description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a bridge having at least one top chord of concrete and a bottom chord of concrete or of metal, said chords being connected to each other by means of structural elements which resist shearing forces.
The two bridge members or chords transmit the moments whilst the structural elements or webs placed between these chords transmit the shearing forces.
2. Description of the Prior Art
In known bridge designs, the webs are constituted by a series of bars arranged in an N-shaped structure. Some of these bars work in compression whilst others work in tension.
The chords and the webs can be of concrete and/or of steel.
In other known designs such as those disclosed, for example, in Swiss patent No. 378,504 and in French patent Application No. 2,494,400, the webs disposed between the chords are constituted by elements of pleated sheet steel. These steel sheets are non-continuous or in other words separated from each other in the direction of the length of the bridge.
In all known designs, should it be desired to obtain webs which are capable of transmitting high shearing forces, it is necessary to increase the number of webs and/or to increase the thickness of these latter. Thus in the case of structures which are intended to sustain very high shearing forces, the construction is heavy and consequently difficult to carry into effect.
The aim of the present invention is to provide a bridge which affords resistance to very high shearing forces while being of lightweight design and easy to construct.
SUMMARY OF THE INVENTION
In accordance with the invention, a bridge having at least one top chord of concrete and a bottom chord of concrete or of metal connected to each other by means of structural elements which afford resistance to shearing forces is distinguished by the fact that the structural elements aforesaid include two pleated or corrugated continuous steel sheets placed on each side of a vertical mid-plane of the bridge, the pleats or corrugations being adapted to extend in a direction which is substantially perpendicular to the length of the bridge.
It has been established by the present Applicant that the fact of replacing known webs of non-continuous pleated steel sheets as disclosed in Swiss Pat. No. 378,504 and in French patent Application No. 2,494,400 by webs of pleated or corrugated continuous steel sheets makes it possible to achieve considerably enhanced resistance of the structure to shearing forces.
Thus the invention permits the construction of a bridge which is capable of withstanding high shearing forces by making use of pleated steel sheets which are of light weight and therefore easy to employ.
In a preferred embodiment of the invention, the continuous steel sheets are made up of two series of flat strips located in two parallel planes, the strips of one of the series being joined to the strips of the other series by means of flat strips which make a predetermined angle with these latter, the junction between the strips being constituted by an arris.
This structure endows the pleated steel sheet with excellent resistance to shearing forces, even when the thickness of said steel sheet is reduced to a few millimeters.
In the application considered in the present invention, the thickness of the steel sheets is within the range of 8 to 12 mm, the amplitude of the pleats is within the range of 10 to 30 cm and the dimension of the steel sheets measured in the direction of said pleats is within the range of 2 to 12 m.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial view in perspective showing a bridge in accordance with the invention.
FIG. 2 is a view in transverse cross-section showing a pleated steel sheet employed in the bridge in accordance with the invention.
FIG. 3 is a partial view in perspective showing an alternative embodiment of a bridge in accordance with the invention.
FIGS. 4 to 17 are schematic views in transverse cross-section showing different alternative embodiments of the invention.
FIG. 18 is a partial schematic side view of a bridge in accordance with the invention and showing how the continuous pleated steel sheet transmits applied forces.
FIG. 19 is a view which is similar to FIG. 18 and illustrates the case of a known bridge constructed with non-continuous pleated steel sheets.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the embodiment of FIG. 1, the bridge in accordance with the invention has a top chord consisting of a concrete slab 1 and a bottom chord consisting of a concrete beam 2 which is connected to the slab 1 by means of two continuous pleated steel sheets 3, 4 disposed on each side of a vertical mid-plane P of the bridge whilst the pleats or corrugations extend in a direction substantially perpendicular to the length of the bridge.
In the example illustrated in FIG. 1, the assembly constituted by the slab 1, the beam 2 and the pleated steel sheets 3, 4 rests on concrete piers 5 by means of lateral bearing blocks 6 extending between the slab 1 and the beam 2. As is apparent from FIG. 2, the continuous steel sheets 3, 4 each have two series of flat strips 7, 8 located in two parallel planes, the strips 7 of one of the series being joined to the strips of the other series by means of flat strips 9 which make a predetermined angle (equal to 37° in the example shown) with these latter, the junction between the strips being constituted by an arris.
Depending on the forces which the bridge is designed to withstand, the thickness of the steel sheets 3, 4 can vary between 8 and 12 mm, the amplitude A of the pleats 7, 9 ; 9, 8 can vary between 10 and 30 cm and the dimension of the steel sheets as measured in the longitudinal direction of these pleats can vary between 2 and 12 m. Moreover, the width of the strips 7, 8, 9 can vary between 0.25 and 0.50 m.
In the case of the embodiment shown in FIG. 1, the assembly constituted by the slab 1, the two pleated steel sheets 3, 4 and the bottom beam 2 forms a tubular structure having a constant triangular cross-section. In view of the fact that the pleated steel sheets 3, 4 are continuous, the lateral surface of the assembly aforesaid is completely closed.
This is also the case with the bridge shown in FIG. 3. In this example, the top and bottom chords are constituted by parallel slabs 10, 11 of concrete. These slabs are connected to each other by means of two pleated steel sheets 3, 4 which are identical with those of the embodiment shown in FIG. 1.
It is further apparent from FIG. 3 that each pleated steel sheet 3, 4 is fitted at each edge adjacent to the slabs 10, 11 with a plate 12, 13 located at right angles to the general plane of the steel sheets 3, 4 and projecting on each side of said plane. On the face which is oriented towards the exterior, each plate 12, 13 is provided with a series of metallic connectors 14 which are embedded in the concrete of the slabs 10, 11.
Thus the steel sheets 3, 4 are securely anchored to the slabs 10, 11.
The mode of connection described in the foregoing can also be adopted in the case of the embodiment shown in FIG. 1.
The continuous steel sheets 3, 4 are not usually of single-piece construction along the full length of the bridge. These sheets are preferably constituted by pleated steel-sheet elements formed in one piece in the direction perpendicular to the length of the bridge and attached to each other in the direction of the length of the bridge by welding, riveting, bolting or the like.
The alternative embodiments shown in FIGS. 4 to 17 have as a common feature the fact that the top chord is a concrete slab 1, 15.
In the alternative embodiments illustrated in FIGS. 4 to 7, the bottom chords are constituted by two metallic beams 16 (as shown in FIGS. 4, 5) or concrete beams 17 (as shown in FIGS. 6, 7), the pleated steel sheets 3, 4 being perpendicular to the slab 15.
In the case of FIGS. 5 and 7, two additional pleated steel sheets 18, 19 extend respectively from the edges of the steel sheet 3 which are adjacent to the slab 15 and to the beam 16 or 17 and form a dihedron, the vertex of which is located in the vertical plane P of symmetry of the bridge.
The two steel sheets 18, 19 which form a dihedron as stated above permit reinforcement of the structure.
FIGS. 8 and 9 are transverse sectional views of the embodiment shown in FIG. 1.
FIGS. 10 and 11 are similar to FIGS. 8 and 9. The difference lies in the fact that the concrete beam 20 which constitutes the bottom chord is of hollow construction and of larger diameter than the beam 2 of FIGS. 1, 8 and 9.
In the embodiments of FIGS. 12 to 17, the bottom chord is constituted by a concrete slab 21, 22, 23, 24, 25, 26 of variable width which is smaller than that of the top slab 15. The pleated steel sheets 3, 4 disposed symmetrically on each side of the vertical plane P of the bridge are inclined at a predetermined angle with respect to this plane.
Among the advantages offered by all the embodiments described in the foregoing are the fact that they are easy to carry out, involve relatively low cost, and are of lightweight construction while at the same time affording distinctly higher resistance to shearing forces than known structures which make use of non-continuous pleated steel sheets in accordance with Swiss patent No. 378,504 and French patent Application No. 2,494,400, as will be demonstrated hereinafter.
In a web of continuous pleated steel sheet 3 (as shown in FIG. 18), applied shearing forces give rise to a uniform field of shear stresses t. Dimensioning of a structure of this type consists in making sure that the shear stress t is lower on the one hand than the buckling stress tv with a suitable safety factor k and lower on the other hand than the permissible value of shear stress tm in the case of steel, namely :
t<tv/k (1)
t<tm (2)
In a web of non-continuous pleated steel sheet 3b, 3c, 3d (as shown in FIG. 19), the applied shearing forces also give rise to shear stresses t but to these are added longitudinal compressive and tensile stresses s (namely stresses parallel to the generator-line of the pleats) which arise from the bending moment which acts upon each web element (so-called "ladder beam" behavior). For the dimensioning of a structure of this type, it is necessary to ensure that the shear stress t is lower than the permissible value tm, that stability remains guaranteed under the combined action of shear stresses and compressive stresses and finally that the compressive stresses are lower than the permissible value sm, namely:
f (t, s)<fm (4)
t<tm (5)
s<sm (6)
Condition (4) is more rigorous than condition (1) but in the case of bridge webs, it is condition (6) which imposes a heavy penalty on non-continuous webs.
Consideration will now be given by way of example to the case of a common type of bridge having a span of 60 m. The height h of the web is approximately 1/20 of the span, namely 3.0 m.
The web of continuous pleated steel sheet has the following characteristics :
thickness: e=0.008 m
width of a panel: 1=0.3 m
amplitude: a=0.18 m
height of web: h=3.0 m
This web of continuous pleated steel sheet is capable of affording resistance to a shearing force T c which has the value: ##EQU1##
The non-continuous web having the same characteristics (see FIG. 19) affords resistance to a shearing force T d ; each web element has a total width L=0.5 m and an inertia I
I=e×L.sup.3 /.sup.12 =0.008×0.53/12=0.0000833 m.sup.4
The web elements are subjected to bending moments M which are of maximum value at the ends, at which they have the following value:
M=+T.sub.d. L/h×H/2=+0.25 T.sub.d
To these moments correspond compressive and tensile stresses: ##EQU2##
It is observed that the ratio T c /T d is very high:
T.sub.c /T.sub.d =370/42.5=8.7
Thus, in respect of identical dimensioning, a web of continuous steel sheet in accordance with the present invention is capable of transmitting a shearing force more than eight times the magnitude of the force which can be transmitted by a web of non-continuous steel sheet.
As can readily be understood, the invention is not limited to the examples of construction described in the foregoing and a large number of modifications may accordingly be contemplated without thereby departing either from the scope or the spirit of the invention.
Thus, each bridge could have more than two continuous pleated steel sheets between the top chord and the bottom chord or chords. | A bridge designed to afford enhanced resistance to shearing forces has at least one top chord (1) of concrete and a bottom chord (2) of concrete or of metal connected to each other by means of structural elements designed to resist shearing forces. These structural elements include two pleated or corrugated continuous steel sheets (3, 4) placed on each side of a vertical mid-plane (P) of the bridge. The pleats or corrugations extend in a direction which is substantially perpendicular to the length of the bridge. | 4 |
This is a division, of application Ser. No. 508,731 filed June 29, 1983, now U.S. Pat. No. 4,490,419.
BACKGROUND OF THE INVENTION
This invention relates to the manufacture of pompons; a method for making pompons, and an apparatus for producing pompons; more particularly, to pompons whose streamer members and whose handle or gripping member are secured to each other by means of ultrasonic welding.
Heretofore many methods for constructing pompons have been employed. Pompons are constructed by attaching a plurality of streamer members, which constitutes the ribbon or the tuft body, to a shaft, handle or other gripping member. Gripping members are usually made of either plastic or wood and the streamer members are made of some suitable cloth, paper or thermoplastic material for durability. Various methods of attachment of the streamer members to a gripping means are known, but all suffer the disadvantage of being labor intensive and thus time-consuming and inefficient. Conventional methods of pompon construction require a human operator to manipulate the gripping member and streamer members so that each may be properly positioned for attachment by mechanical means.
Many conventional manufacturing methods require that the tuft or streamer body be prefabricated to have a collar member from which the individual streamer members depend. The collar member of the tuft body is placed by a human operator about a handle member and secured thereto by either glue, cement, staple or clamp means. Although other construction methods are also known, they too require a human operator to position the streamer members to the handle member whereupon the human operator effects a mechanical attachment of the streamers to the handle member. All conventional methods of attachment of streamers to handles require attachment by mechanical means. Often in pompons produced by conventional methods the staples become detached or the streamers and handles work loose of the glue or clamp means from the continued stress to which a pompon is subjected during use.
Conventional methods for attachment of tuft bodies to handle members are not suitable to accomplishment by an automated construction method, since each requires the time-consuming process of human placement of the tuft body into position on a gripping member for mechanical attachment. Thus, conventional construction methods are not suitable to the development of an automated assembly procedure for the efficient production of pompons.
SUMMARY OF THE INVENTION
This invention discloses a pompon construction which may be accomplished by an automated construction method, which greatly reduces the amount of human manipulation required to produce a pompon.
The pompons of this invention comprise a gripping member having a thermoplastic crown piece mating surface to which a plurality of thermoplastic streamers are ultrasonically fused.
An apparatus has been devised by which production of pompons of the invention may be automated which comprises a means for moving a formed cluster of streamers into a position intermediate of an ultrasonic welding horn and the crown piece mating surface of a handle or gripping member, and a means for contacting and energizing an ultrasonic welding head with the cluster of streamers so as to fuse the streamers to the crown piece by ultrasonic vibrations.
The process of the invention comprises forming thermoplastic streamer clusters and ultrasonically welding the clusters to a thermoplastic mating surface attached to a handle or gripping member.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a method and apparatus for producing pompons which is automated so that minimum human manipulation of the materials used is required.
A further object is to attach pompon streamers to a pompon gripping member or handle in such a way that the streamers will remain permanently and securely affixed to the handle, regardless of the amount of stress to which the pompon is subjected.
Still another object is to produce a pompon which will withstand normal stress at minimal cost and production time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a gripping member with a crown piece attached and streamer members fused to the crown piece in a melted mass at the point of attachment.
FIG. 2 is a side view of the gripping member with the crown piece attached.
FIG. 3 is a top view of the knurled surface of the crown piece.
FIG. 4 is a diagrammatic representation of an apparatus by which the streamer clusters are automatically formed and then ultrasonically welded to the crown piece mating surface of a gripping member.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the pompon 5 of this invention comprises a tuft or streamer body 7 which is secured by ultrasonic welding to a grip member 9. Tuft body 7 is formed of a plurality of individual thermoplastic streamer members 14. For clarity of illustration only portions of a few representative streamer members are illustrated in FIG. 1, but it is to be understood that any number of individual streamer members 14, which may be at any desired length, may be employed to form tuft body 7.
Grip member 9, as best illustrated by FIG. 2, comprises a handle member 12 to one end of which a thermoplastic crown piece 10 is securely affixed. The thermoplastic streamer members 14 forming tuft body 7 are secured to the mating surface 30 of thermoplastic crown piece 10 of grip member 9 by ultrasonic welding. The junction of streamer members 14 to crown piece 10 is accomplished by positioning a bundle or cluster of streamer members 14 upon mating surface 30 of crown piece 10 whereupon ultrasonic vibrations at about a frequency 20k Hz are transmitted through that portion of each streamer member 14 which overlies crown piece 10 and hence into crown piece 10. The vibratory energy is converted to heat causing that portion of the thermoplastic material of each streamer member 14 which overlies crown piece 10 to melt. Further, at least portions of the thermoplastic crown piece 10 which underly streamer members 14 also melt. That portion of each streamer member 14 which overlies crown piece 10 which is melted by ultrasonic vibrations comingles with the melted portion of other tuft body streamer members to form a melt mass 16. Upon formation of melt mass 16, ultrasonic vibration is discontinued, and melt mass 16 solidifies and fuses to the underlying crown piece 10, thus affecting a secure attachment of the unaffected portions of each streamer member 14 to crown piece 10 through melt mass 16.
As noted above, grip member 9 comprises a handle member 12 and a thermoplastic crown piece 10. As illustrated, handle member 12 is preferably an elongated generally tubular element. If desired, a handle member of other design, such as a looped handle which is placed over four fingers of the hand and gripped against the palm, may be used. The handle member may be of any desired shape or material provided only that it is capable of being securely affixed with a crown piece of thermoplastic material.
Crown piece 10, as illustrated, is preferably disk shaped. Other shapes for crown piece 10 may be employed if desired, provided only that the crown piece be formed to have a suitable mating surface 30 for attachment of melt mass 16. As illustrated by FIGS. 2 and 3, it is preferred that the anterior mating surface 30 of crown piece 10 be formed with a plurality of knurled projections 18. Such projections 18 are preferably elevated 40/1000 of an inch above the mating surface 30. The precise dimensions of projections 18 may be changed depending upon the particular thermoplastic materials employed for the streamer members 14 and crown piece 10, to insure that the streamer materials and projection will each begin to melt at approximatley the same time when sumitted to ultrasonic vibrations. There exists a correlation between the dimensions of such projections 18 and the streamer members 14 to be welded to the crown piece 10 which may readily be determined for any desired combination of thermoplastic materials or volume of a streamer cluster. For most applications a dimension wherein the projections 18 are elevated by 40/1000 of an inch is entirely satisfactory. The streamer members 14 and the material of which such projections 18 are made should have approximately similar or compatible melt indexes so that each will melt to one another at about the same time. Upon application of ultrasonic vibrations to crown piece 10, the knurled projecting surfaces 18 melt more quickly than does the bulk mass of crown piece 10, hence insuring a quick and secure attachment of melt mass 16 to the anterior mating surface 30 of crown piece 10 through fusion with the melt provided by the knurled projections 18.
Grip member 9, comprising handle member 12 and crown piece 10, may be formed as an integral unit as by injection molding of a suitable thermoplastic material, or its individual components may be separately formed and suitably assembled in a separate operation. When formed as an integral unit, then grip member 9 must be fashioned from a thermoplastic materials which is compatible for ultrasonic welding with the thermoplastic composition of which streamer members 14 is formed.
Streamer members 14 may be formed from any thermoplastic and need not be formed of the same thermoplastic material as crown piece 10. Streamer members 14 are preferably secured to crown piece 10 at about the midpoint of streamer members 14, although, streamer members 14 may be secured to crown piece 10 at any point of streamer members 14. The number of streamer members 14 is not critical, but there should be a number of streamer members 14 sufficient, when secured to crown piece 10, to give the desired volume to the tuft body of the pompon. Preferably, streamer members 14 are, before welding, about twice the length of gripping member 12.
Suitable thermoplastic materials from which streamer members 14 and crown piece 10 may be formed include among others, polyvinyl chloride, nylon, fluorocarbons, polyethylene, polystyrene and polypropylene. Streamer members 14 and crown piece 10 may be fashioned of the same thermoplastic material or may be comprised of different thermoplastic materials, provided only that when different thermoplastics are employed that they are compatible for ultrasonic welding.
The apparatus, diagrammatically illustrated by FIG. 4, by which the production of pompons may be automated comprises in its general parts a sheet stock storage rack A, a ribbon cluster forming line B through which thermoplastic sheet stock from rack A is drawn, moved and formed into a continuous cluster of individual ribbon members which are moved into station below an ultrasonic welding horn and above the crown piece of a grip member; a grip member holding means C for holding a grip member in station below an ultrasonic welding horn; ultrasonic welding means D; signaling means E by which movement of sheet stock material through forming line B is stopped, the ultrasonic welding means D is actuated to weld the ribbon cluster to the crown piece of a grip member and upon completion of the weld the movement of sheet material through flow line B is reinitiated; and a shearing means F which is actuated by signaling means E to sever the ribbon cluster to which a grip member has been welded from the continuous sheet material.
Sheet stock storage rack A may comprise any suitable framework 33 within which thermoplastic sheet stock rolls 34 may be positioned for free rotation. Thermoplastic sheet stock 32 is thus freely withdrawable from any given sheet stock roll 34.
Ribbon cluster forming line B comprises a series of rollers, some are tensioning rollers like 36, 38, 40 and 42 to maintain the sheet stock flowing through the line taut, and some are pairs of powered rollers like rollers 48, 50, 58, 62 and 72, 74 by which sheet stock material is drawn through the ribbon cluster forming line B and properly position for ultrasonic welding to a grip member 9. Forming line B contains a ribbon cutting wheel 46 and teflon cutting block 44 which forms the means through which sheet stock 32 is drawn and cut into a plurality of individual ribbon members. Power is supplied directly to rollers 48, 58 and 72 in a manner which is responsive to and coordinated with the operations of ultrasonic welding means D. A power transmission means G, comprising an electric motor 52 which through drive change 52b drives an air clutch 54 which by belt 54a drives an in/out gear box 55 from which through appropriate chain drives 55a power is supplied to rollers 48, 58 and 72. Powered rollers 48, 58 and 72 are preferably of rubber or other resilient composition having a high coefficient of friction. Rollers 48 and 72 are mounted in frictional engagement with rollers 50 and 74, respectively, which rollers 50, 74 are also of rubber or other resilient composition having a high coefficient of friction. Roller 58 is mounted in frictional engagement with a toothed wheel 60, preferably of metallic construction, which hereafter shall be referred to as the crimping wheel. Sheet stock is moved through ribbon cluster forming line B by powered roller pairs 48, 50 and 58, 60 and 72, 74. Ribbon cutting wheel 46 comprises an axle to which is mounted in closely spaced relationship a plurality of thin sharp edged metallic cutting disks. Overlying cutting wheel 46 is a block 44, preferably of teflon, which is provided with a plurality of recesses which correspond to and receive the top portion of each metallic cutting disk of cutting wheel 46. Cutting wheel 46 is provided with constant rotational motion from motor 52 by belt drive 52a. As sheet stock passes under block 44 and over ribbon cutting wheel 46 the sheet material is cut into a plurality of individual ribbon elements 32a, hereafter called ribboned sheet stock. Ribbon cluster forming line B is also provided with a channeling sleeve 56 which receives ribboned sheet stock 32a from rollers 48, 50 and channels the ribboned sheet stock 32a into a closely spaced bunched relationship, or what shall be called a ribbon cluster 32b, which passes to rollers 58, 60. Channeling sleeve 56 comprises a flat open tray having small perpendicular side walls. End 56a of sleeve 56 facing rollers 48, 50 is at least as wide as the width of sheet stock 32 which fed to forming line B. Channeling sleeve 56 narrows towards end 56b, the width of end 56b being equal to the width desired for the ribbon cluster 32b, generally from about three-quarters to about one inch in width. A second channeling sleeve 53 is also provided in forming line B, on the side opposite of roller 58 from main channeling sleeve 56. Second channeling sleeve 53 comprises a hollow tubular element having the same width as is desired for ribbon cluster 32b, generally from about three-quarters to about one inch in width. Second channeling sleeve 53 extends in length from a point just adjacent to roller 58 into a point just adjacent to the ultrasonic welding station of ultrasonic welding means D.
The ultrasonic welding means D may comprise any of the commercially available ultrasonic assembly units, such as for example, a Branson Model 8400 marketed by Branson Sonic Power Company. Preferably, the ultrasonic welding means D employed should be an integrated welder. Integrated welders include a power supply, controls, indicators, an actuator, and an electronic programmer which automatically actuates the power supply and controls ultrasonic exposure and pneumatic sequences. Integrated welders are housed in compact housings which are supported by an assembly stand. As diagrammatically illustrated in FIG. 4, the ultrasonic welding means D comprises an ultrasonic welder control housing 70, ultrasonic welding horn 68 and assembly stand 69. Activator switch 66 is illustrated as mounted to assembly stand 69. When activator switch 66 is tripped, in a manner to be explained subsequently, it signals the electronic programmer of the ultrasonic welding means D which then initiates a welding cycle. Upon initiation of a welding cycle, air clutch 54 is pneumatically disengaged by a pneumatic signal generated by the electronic programmer of welding means D, and flow of sheet stock material through forming line B is stopped. Upon completion of a welding cycle a pneumatic signal is generated by the electronic programmer and causes air clutch 54 to reengage and flow of sheet material through forming line B is resumed. FIG. 4 diagrammatically illustrates as broken lines the electronic and pneumatic signaling means E by which sequencing control signals are conveyed through the apparatus.
A grip member holding means C is positioned within flow line B at a point just below the welding station of ultrasonic welding means D. Holding means C may be any device which will hold an individual grip member 9 in station below welding horn 68 of welding means D such that crown piece 10 of grip member 9 will underlie and contact the streamer cluster 32b which passes over such station. The holding means C may be a slotted platform, wherein the holding slot is of a width slightly greater than handle member 12 and smaller than the diameter of crown piece 10 which comprise grip member 9. Wherein the holding means C comprises a slotted platform, the platform is secured at a point within the framework which supports the components of forming line B which underlies the streamer cluster 32b and welding horn 68 and is positioned such that the slot opens on an angle towards roller 72.
Finally, the product end of forming line B is provided with an automatic shear means F which, upon activation of a welding cycle wherein flow of materials through line means B is stopped, is itself actuated and shears that portion of the ribbon cluster to which a grip member 9 has been previously welded, free from the ribboned sheet stock material.
The apparatus diagrammatically illustrated in FIG. 4 operates in accordance with the following description. Thermoplastic sheet stock 32 is drawn from each sheet stock roll 34 and directed around tensioning rollers 36, 38, 40 and 42 which maintains sheet stock 32 in taut relationship. Sheet stock 32 is drawn from the last tensioning roller 42 under cutting block 44 and across cutting wheel 46. Constant rotation is provided to cutting wheel 46 by motor 52 through belt drive 52a. The plurality of cutting disks forming cutting wheel 46 cuts sheet stock 32 passing thereover into a plurality of ribbons, namely ribbon sheet stock 32a. The ribboned sheet stock 32a leaving cutting wheel 46 is passed between powered rollers 48, 50 and through channeling sleeve 56 by which the ribboned sheet stock 32a is funneled or formed into a ribbon cluster 32b. The ribbon cluster 32b is passed between powered rollers 58 and crimping wheel 62, wherein during passage over crimping wheel 62 crimp is imparted to the ribbon members comprising ribbon cluster 32b. Crimping of the ribbon members helps to impart extra body or fluffiness to the pompon tuft body 7 which is ultimately formed from the ribbon cluster 32b. The crimped ribbon cluster 32b leaving crimping wheel 60 is passed through a second channeling sleeve 57 which insures that the individual ribbon members of ribbon cluster 32b are maintained in a tightly bunched relationship as they pass over a grip member 9 held in station below welding horn 68 by grip member holding means C.
Crimping wheel 60 is provided with a trip arm 64 which has a plane of rotation which brings trip arm 64 into contact with actuator switch 66 whenever crimping wheel 60 completes one cycle of rotation. When actuator switch 66 is tripped it generates a signal which activates the internal programmer of welding means D which begins a welding cycle. The programmer of welding means D generates a pneumatic signal which disengages air clutch 54, stopping power transmission to rollers 48, 58 and 76, thus stopping movement of sheet stock through forming line B. Thereafter, in conformance with the programmer control, welding horn 68 moves down into station into contact with that portion of streamer cluster 32b which overlies the crown piece 10 of a grip member 9 held in station by holding means C. The welding horn 68 is then energized and transmits ultrasonic vibrations through that portion of ribbon cluster 32b which overlies crown piece 10 and thus produces a meld fusion of ribbon cluster 32b to crown piece 10 of grip member 9. Typically, the ultrasonic welding means D is programmed to continue ultrasonic vibations for a duration of about one to about two seconds and add a contact pressure of about twenty to about forty psi. Upon completion of the ultrasonic weld, the programmer retracts welding horn 68 to its standby position and causes a pneumatic signal to be generated which reengages air clutch 54, resuming flow of sheet flow material through forming lines B. As may be appreciated from the above description, the end to end length of the ribbon members 14 which form tuft body 7 of pompon 5 produced in this apparatus is directly related to the diameter of crimping wheel 60. Thus, pompons having any desired length of streamers may be formed by changing the diameter of crimping wheel 60.
The end of the ribbon cluster to which a grip member 9 is now welded is passed between powered rollers 72, 74. When air clutch 54 is reengaged, power to rollers 72, 74 is resumed and the ribbon cluster is drawn therebetween by frictional engagement. Since rollers 72, 74 are of rubber or other resilient composition, the grip member 9 welded thereto is drawn from holding means C and easily passes between rollers 72, 74 without difficulty. The ribbon cluster 32b to which gripping member 9 has been welded is passed to automatic shear means F which is also actuated by actuator signal 66 and, upon the next welding cycle, automatic shear means F operates to shear the ribbon cluster free from the continuous sheet stock. The completed pompon 5 thereupon falls free into a storage receptable 78.
Persons having ordinary skill in the art may appreciate that various changes and modifications may be made to the pompon construction and method for making same which are described above which would not depart in scope or spirit from that which is claimed hereafter. | An apparatus as disclosed by which production of pompons of the inventions comprising a gripping member having a thermoplastic crown piece mating surface to which a plurality of thermoplastic streamers are ultrasonically fused may be utimated which comprises a means for moving a form cluster of streamers into a position intermediate of an ultrasonic welding horn and the crown piece mating surface of a handle or gripping member and a means for contacting and engerizing an ultrasonic welding head with the cluster of streamers so as to fuse the streamers to the crown piece by ultrasonic vibrations. | 3 |
FIELD OF THE INVENTION
The present invention relates to a step unit, which includes a step member adjacent to a vehicle sliding door.
BACKGROUND OF THE INVENTION
Conventionally, a step unit is provided on a vehicle main body to be adjacent to a vehicle sliding door thereof. For example, referring to Non-Patent Document 1, a step unit includes a step member (step) and a rail plate member. A lower rail extending in the opening-closing direction of a vehicle sliding door is provided on the lower surface of the step member. The lower rail supports rollers coupled to the sliding door, so that the rollers and the sliding door are guided along the lower rail. Such a step unit has a cutout portion formed in a part of the lower rail. With the rail plate member (sliding door lower rail plate) removed, the cutout portion allows rollers to be supported by the lower rail or to be removed from the lower rail.
PRIOR ART DOCUMENT
Non-Patent Document
Non-Patent Document 1
Repair Manual for TOYOTA ALPHARD VELLFIRE, volume F, May 2008 (DH-282 through DH-285, DH-246, DH-247 and other pages)
SUMMARY OF THE INVENTION
In the above described step unit, the step member and the fastening piece formed by bending the rail plate member each have a fastening hole, and the step member and the rail plate member are assembled together by a bolt passed through the fastening holes. However, to arrange these members of the step unit such that the fastening holes match each other, the rail plate member needs to be held underneath the step member in by touch. This complicates the assembling process.
Further, in the above described step unit, the rail plate member receives a great load from the rollers, and the lower rail has a low rigidity because of its discontinuous structure on the ends of the cutout portion. The rail plate therefore has a complicated shape. That is, a typical rail plate member is formed by welding two metal sheets together, such that one of the sheets protrudes to be flush with the inner surface of the lower rail. A typical rail plate member also has a structure for reinforcing the ends of the cutout portion of the lower rail. The rail plate member has such a complicated structure.
Accordingly, it is an objective of the present invention to provide a step unit that facilitates the assembly and simplifies the shape of a rail plate member.
To achieve the foregoing objective and in accordance with one aspect of the present invention, a step unit including a step member and rail plate is provided. The step member is provided on a vehicle main body to be adjacent to a vehicle sliding door. The step member has, on a lower surface thereof, a pair of lower rails extending in an opening-closing direction of the sliding door. The rail plate member is arranged at a cutout portion, which is formed in a part of one of the lower rails. The rail plate member makes the lower rail continuous in the opening-closing direction. Rollers are coupled to the sliding door and arranged between the pair of lower rails. The rollers, together with the sliding door, are guided by the lower rails in the opening-closing direction. The step member is molded of a plastic material and has an insertion slit and a support extension, the insertion slit extending through the step member in the vertical direction at a position that corresponds to the cutout portion. The support extension extends from an end of the cutout portion of the lower rail to support the rail plate member against load applied to the rail plate member by the rollers. The rail plate member is assembled to the step member by being inserted through the insertion slit from above the step member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view from above illustrating a step unit according to one embodiment of the present invention;
FIG. 2 is a perspective view from below illustrating the step unit shown in FIG. 1 ;
FIG. 3 is a partial plan view illustrating the step unit shown in FIG. 1 ;
FIG. 4A is a cross-sectional view taken along line 4 A- 4 A of FIG. 3 ;
FIG. 4B is a cross-sectional view taken along line 4 B- 4 B of FIG. 3 ;
FIG. 5 is an exploded perspective view illustrating the pulley and the structure for supporting the pulley shown in FIG. 2 ;
FIG. 6 is a partial bottom view illustrating the pulley and the structure for supporting the pulley shown in FIG. 2 ;
FIG. 7 is an explanatory exploded perspective view from below illustrating the support extensions and the rail plate member in the step unit shown in FIG. 1 ;
FIG. 8 is a partial bottom view showing the step unit shown in FIG. 1 ; and
FIG. 9 is a cross-sectional view taken along line 9 - 9 of FIG. 8 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the present invention will now be described with reference to FIGS. 1 to 9 .
A vehicle has a step unit 1 shown in FIG. 1 , which is located adjacent to a vehicle sliding door (not shown).
As shown in FIG. 1 , the step unit 1 of the present embodiment is formed mainly by a drive device (motor unit) 2 for opening and closing the sliding door and a substantially plate-like step member (step) 3 . The step unit 1 is fixed to the main body (not shown) of the vehicle. The entire upper surface of the step unit 1 is covered with an unillustrated thin scuff plate (decorative member). The upper surface of the drive device 2 (the lower surface of the thin plate-like scuff plate) is covered with an unillustrated rigid plate (cover).
The step member 3 is formed by molding a plastic material. The step member 3 is located in the passenger compartment at a position adjacent to the sliding door in the closed state, and includes a flat plate portion 4 , on which an occupant places a foot when getting in or out of the vehicle, and an accommodation portion 5 . The accommodation portion 5 is formed continuous to the flat plate portion 4 and is located on a side of the flat plate portion 4 in the opening direction of the sliding door, or rearward of the flat plate portion 4 . A part of the drive device 2 is fixed and accommodated in the accommodation portion 5 .
Specifically, when the step unit 1 is installed in the vehicle, a bottom 5 a of the accommodation portion 5 is located at a lower position than an upper surface 4 a of the flat plate portion 4 as shown in FIGS. 3 , 4 A and 4 B. The height (depth) of the bottom 5 a of the accommodation portion 5 is determined based on the shape of the drive device 2 . That is, as shown in FIGS. 1 and 3 , the drive device 2 of the present embodiment includes a motor 2 a, which is a drive source, an output portion 2 b, which is attached to the motor 2 a and has a gear and an electromagnetic clutch, a control circuit portion 2 c, which is installed in the output portion 2 b . As shown in FIGS. 4A and 4B , the accommodation portion 5 includes a motor accommodating section 5 b, an output portion accommodating section 5 c, and a circuit accommodating section 5 d, which correspond to the motor 2 a, the output portion 2 b, and the control circuit portion 2 c, respectively. The drive device 2 is fixed by screws such that it partly contacts the bottom 5 a of the accommodation portion 5 . That is, a part of the drive device 2 is located lower than the upper surface 4 a of the flat plate portion 4 . More specifically, one third or more of the entire thickness of the drive device 2 in the vertical direction is located below the upper surface 4 a of the flat plate portion 4 . In the example shown in FIG. 4B , substantially half the entire thickness is located below the upper surface 4 a . Also, a peripheral wall 6 is molded integrally with the step member 3 to encompass (almost the entire circumference of) the accommodation portion 5 as shown in FIGS. 1 , 3 , and 4 . The peripheral wall 6 extends to a position above the upper surface 4 a of the flat plate portion 4 .
As shown in FIG. 2 , pulleys 11 , 12 are located on the lower surface of the step member 3 . A loop belt 13 is rotationally supported by the pulleys 11 , 12 and substantially extends in the opening-closing direction of the sliding door. The drive device 2 is configured to cause the belt 13 to rotate. That is, as shown in FIG. 4A , an output shaft 2 d of the output portion 2 b of the drive device 2 extends through a through hole 5 e formed in the bottom 5 a of the accommodation portion 5 and protrudes from the lower surface of the step member 3 . The output shaft 2 d transmits power that is output by the drive device 2 to the belt 13 via a power transmitting portion 14 (see FIG. 2 ), which is provided on the lower surface of the step member 3 , thereby rotating the belt 13 . In the present embodiment, the opening-closing direction of the sliding door substantially corresponds to the front-rear direction of the vehicle. The position of the belt 13 is regulated by the pulleys 11 , 12 , which are located at ends of the step member 3 in the vehicle front-rear direction, and a regulation portion 15 , which is located between the pulleys 11 and 12 and extends from the lower surface of the step member 3 . The regulation portion 15 is molded integrally with the lower surface of the step member 3 .
A pair of non-annular shaft support portions 16 , which serve as a shaft support portion, are molded integrally with the step member 3 . The pulley 11 , which is located at the front end of the step member 3 , is supported by the non-annular shaft support portions 16 as shown in FIGS. 5 and 6 . The non-annular shaft support portions 16 are formed to engage with and rotationally support the pulley 11 . Specifically, the non-annular shaft support portions 16 are separated in the vertical direction, and each have an opening 16 a, which opens in a direction opposite to the direction of the force that is perpendicular to the axis and applied to the pulley 11 by the belt 13 in a taut state (in other words, the openings 16 a open substantially in the forward direction of the vehicle). A shaft 11 a of the pulley 11 is inserted in the non-annular shaft support portions 16 via the openings 16 a . Accordingly, the pulley 11 is fitted to and rotationally supported by the non-annular shaft support portions 16 . The width of the openings 16 a is slightly smaller than the diameter of the shaft 11 a of the pulley 11 . Therefore, the pulley 11 , which is fitted in the non-annular shaft support portions 16 , is supported by the non-annular shaft support portions 16 , so as not to fall off from the openings 16 a unless it receives a force of a certain magnitude. The pulley 12 , which is located at the rear end of the step member 3 , is rotationally supported by the cover of the power transmitting portion 14 as shown in FIG. 2 .
A pair of lower rails 21 , 22 is molded integrally with the lower surface of the step member 3 as shown in FIG. 2 . The lower rails 21 , 22 extend in the opening-closing direction of the vehicle sliding door (substantially, the front-rear direction of the vehicle). In the present embodiment, the lower rails 21 , 22 are curved inward toward the center of the passenger compartment at a front portion. The lower rails 21 , 22 are connected to each other at both ends in the longitudinal direction. As shown in FIGS. 7 and 8 , a cutout portion 21 a is formed in one of the lower rails, that is, in a part of the lower rail 21 . A rail plate member 31 is arranged at the cutout portion 21 a to make the lower rail 21 continuous in the opening-closing direction of the sliding door (substantially, in the front-rear direction of the vehicle). Rollers 32 (see FIG. 8 ) are supported to roll between the lower rails 21 , 22 (including the rail plate member 31 ). The rollers 32 are coupled to the sliding door, for example, via brackets (not shown). Thus, the rollers 32 and the sliding door are guided in the opening-closing direction by the lower rails 21 , 22 . The rollers 32 are coupled to the belt 13 via brackets (not shown), so that, as the belt 13 rotates, the rollers 32 are moved in the opening-closing direction (while being guided by the lower rails 21 , 22 ).
Specifically, as shown in FIGS. 7 to 9 , the step member 3 has an insertion slit 23 extending through the step member 3 in the vertical direction at a position that corresponds to the cutout portion 21 a . Also, the step member 3 has a pair of support extensions 21 b . The support extensions 21 b extend from the ends of the cutout portion 21 a of the lower rail 21 to support the rail plate member 31 against the load applied to the rail plate member 31 by the rollers 32 (see FIG. 8 ). As shown in FIG. 8 , the pair of support extensions 21 b extend from the ends of the cutout portion 21 a of the lower rail 21 in the direction in which load is applied (upward as viewed in FIG. 8 , and toward the outside with respect to the vehicle width direction), and extend toward each other without being connected to each other (so that there is a space therebetween). Also, the support extensions 21 b are thicker than the lower rail 21 in the direction in which the load is applied (the up-side direction as viewed in FIG. 8 ).
The rail plate member 31 is installed by being inserted through the insertion slit 23 from above the step member 3 as shown in FIG. 7 . The rail plate member 31 is formed by processing a metal plate. As shown in FIGS. 1 and 7 , the rail plate member 31 has an angled portion 31 a at the upper edge (the upper edge in a state after being installed). The angled portion 31 a extends in a direction perpendicular to the vertical direction, or into the passenger compartment with respect to the vehicle width direction in the present embodiment. The rail plate member 31 is assembled with the step member 3 by being inserted into the insertion slit 23 such that the lower side of the angled portion 31 a contacts the upper surface of the step member 3 . The rail plate member 31 is fixed to the step member 3 through press-fitting as shown in FIG. 9 . Specifically, the rail plate member 31 has a pair of press-fit portions 31 b on both sides. The press-fit portions 31 b slightly protrude sideways and are spaced from each other in the vertical direction to be pressed against the ends of the cutout portion 21 a of the lower rail 21 . When the rail plate member 31 is inserted through the insertion slit 23 from above the step member 3 , the press-fit portions 31 b are pressed against the ends of the cutout portion 21 a of the lower rail 21 . At this time, the sides of the cutout portion 21 a may be slightly shaven or elastically deformed by the press-fit portions 31 b.
In the above described configuration, the rail plate member 31 can be removed to insert rollers 32 into the space between the lower rails 21 , 22 through the cutout portion 21 a or remove the rollers 32 from the space between the lower rails 21 , 22 . When the drive device 2 is operated, the belt 13 is rotated. Accordingly, the rollers 32 are moved while being guided by the lower rails 21 , 22 , and the sliding door is operated to open or close. The output shaft 2 d of the drive device 2 or the housing of the drive device 2 has an seal ring, which is not shown, so that water is completely or almost completely prevented from entering the interior of the drive device 2 or the bottom 5 a of the accommodation portion 5 through the through hole 5 e formed in the bottom 5 a of the accommodation portion 5 .
The present embodiment has the following advantages.
(1) The step member 3 has an insertion slit 23 extending through the step member 3 in the vertical direction at a position that corresponds to the cutout portion 21 a, which is formed in a part of the lower rail 21 . The rail plate member 31 is installed by being inserted through the insertion slit 23 from above the step member 3 . This configuration facilitates the assembly process. Also, the step member 3 has a pair of support extensions 21 b , which extends from the ends of the cutout portion 21 a of the lower rail 21 to support the rail plate member 31 against the load applied to the rail plate member 31 by the rollers 32 . Accordingly, the rail plate member 31 is prevented from being deformed by the load applied by the rollers 32 . Further, since the support extensions 21 b extend from the ends of the cutout portion 21 a , the rigidity of the ends of the cutout portion 21 a is increased. This eliminates the need for providing, the rail plate member 31 with a structure for reinforcing the ends of the cutout portion 21 a . Therefore, the shape of the rail plate member 31 can be simplified as in the present embodiment, in which the rail plate member 31 is formed by a single plate (metal plate), for example. Further, if a part of a rail plate member is caused to protrude such that it is flush with the inner surface of a lower rail (the surface that contacts rollers) as in the conventional art, the corners of that part will be rounded. Accordingly, steps are likely to be formed between the ends of the cutout portion of the lower rail and the rail plate member. In the present embodiment, the rail plate member 31 does not need to be molded to protrude. Therefore, it is easy to prevent such steps from being formed. This contributes to smooth movement of the rollers 32 and the sliding door. Further, unlike conventional step members that are formed through sheet-metal processing, the step member 3 is formed through molding a plastic material. This allows the step member 3 to have wide variety of shapes. Accordingly, for example, the support extensions 21 b can be easily molded integrally with the step member 3 .
(2) Since the rail plate member 31 is fixed to the step member 3 through press-fitting, fasteners such as bolts and rivets are not necessary. The number of components of the step unit is thus reduced.
(3) Since the rail plate member 31 is press fitted in the insertion slit 23 to be pressed against the ends of the cutout portion 21 a of the lower rail 21 , steps between the ends of the cutout portion 21 a and the rail plate member 31 are further reduced. Therefore, it is possible to directly suppress chattering of the rail plate member 31 in the opening-closing direction of the sliding door, that is, the direction of movement of the rollers 32 .
(4) The angled portion 31 a , which extends in a direction perpendicular to the vertical direction, is provided at the upper end of the rail plate member 31 . The angled portion 31 a reliably prevents the rail plate member 31 from fall off (the insertion slit 23 of) the step member 3 . Also, with the rail plate member 31 assembled with the step member 3 , the rail plate member 31 can be easily detached from the step member 3 by pushing the lower surface of the angled portion 31 a upward, for example, with a jig.
(5) The pair of support extensions 21 b extend from the ends of the cutout portion 21 a of the lower rail 21 in the direction in which load is applied (upward as viewed in FIG. 8 ) and, extend toward each other. In this case, when arranging the rollers 32 in the space between the lower rails 21 , 22 through the cutout portion 21 a , the support extensions 21 b do not hamper the operation. In addition, since both ends of the rail plate member 31 are supported by the support extensions 21 b , the rigidity of the rail plate member 31 against load applied by the roller 32 is improved compared to a case in which only one end of the rail plate member 31 is supported. Also, the rigidity of the ends of the cutout portion 21 a is increased. In the above described configuration, the rail plate member 31 can be easily pushed upward manually or with a jig by utilizing the space between the support extensions 21 b . The rail plate member 31 thus can be easily removed.
(6) Since the support extensions 21 b are thicker than the lower rail 21 in the direction in which the load is applied (the up-down direction as viewed in FIG. 8 ), the rail plate member 31 can be firmly supported, while achieving the advantage of the item (5).
The above described embodiment may be modified as follows.
In the above described embodiment, the rail plate member 31 is fixed to the step member 3 through press-fitting. However, the rail plate member 31 may be fixed through other configuration. For example, the rail plate member 31 may be fixed to the step member 3 by using fasteners such as bolts or rivets. In this case, for example, the rail plate member 31 may be fixed by the angled portion 31 a and a fastener that is passed through the step member 3 . To prevent the fastener from interfering with the rollers 32 , the angled portion 31 a is preferably fixed such that it extends in a direction away from the pair of lower rails 21 , 22 (toward the outside of the passenger compartment with respect to the vehicle width direction). In the above described embodiment, the rail plate member 31 is press fitted to be pressed against the ends of the cutout portion 21 a of the lower rail 21 . However, the rail plate member 31 may be press fitted to be pressed in the vehicle width direction (up-down direction as viewed in FIG. 8 ).
In the above described embodiment, the angled portion 31 a , which extends in a direction perpendicular to the vertical direction, is provided at the upper end of the rail plate member 31 . However, the present invention is not limited to this, and a rail plate member that does not have the angled portion 31 a may be used. In such a case, for example, the support extensions 21 b of the step member 3 may have a bottom for preventing the rail plate member from falling off (preferably through integral molding).
In the above illustrated embodiment, the pair of support extensions 21 b extend from the ends of the cutout portion 21 a of the lower rail 21 in the direction in which load is applied (upward as viewed in FIG. 8 ), and extend toward each other. However, a support extension 21 b may be formed only at one of the ends of the cutout portion 21 a.
In the above described embodiment, the rail plate member 31 is formed by processing a metal plate. However, the rail plate member 31 may be formed, for example, through molding plastic.
In the above described embodiment, the step unit 1 includes the drive device (motor unit) 2 for opening and closing a vehicle sliding door. However, the step unit 1 does not necessarily include the drive device 2 . That is, a step member that does not include the accommodation portion 5 may be used. In this case, the pulleys 11 , 12 , the belt 13 and the power transmitting portion 14 are not necessary.
Description Of The Reference Numerals
3 . . . Step Member, 21 , 22 . . . Lower Rails, 21 a . . . Cutout Portion, 21 b . . . Support Extensions, 23 . . . Insertion Slit, 31 . . . Rail Plate Member, 31 a . . . Angled Portion, 32 . . . Rollers. | A step unit includes: a step member which is provided with a pair of lower rails extending in an opening and closing direction of a slide door of the vehicle; and a rail plate member which is provided to a cutout formed in a part of either of the lower rails and which continuously connects the lower rails in the opening and closing direction. The step member is molded using a resin material and is provided with an insertion hole which vertically penetrates through the step member at a position corresponding to the cutout; and a support extension section which is extended from a side end of the cutout of the lower rail. The rail plate member is mounted to the step member by being inserted so as to penetrate through the insertion hole from above the step member. | 4 |
TECHNICAL FIELD
[0001] This invention relates to an attachment, in particular to an hydraulic attachment which is particularly suited for use with skid steer loaders including small mechanical loaders such as stand on min-skid steer loaders. The attachment of the invention however is suitable for attachment to any form or size of machinery or vehicles. In a particular aspect, the present invention relates to an attachment which serves as a post driver for use in driving posts such as fence posts or guard rail posts into the ground.
BACKGROUND ART
[0002] Where it is desired to install posts into the ground such as fence posts or guard rails posts, the common procedure is to use a earth drilling device to form a hole in the ground and thereafter install a post in the hole which is backfilled or filled with concrete to hold the post firmly in position. Alternatively the hole can be made manually. In either situation, the procedure is relatively time consuming and tedious where a large number of posts are to be installed. Removal of posts from the ground can also prove difficult.
[0003] Some of the large earth working machines such as backhoes can be provided with pile driving attachments which are mounted on an articulated arm at the rear of the machine. It is difficult to manipulate the pile driver close to the post to be driven into the ground in these machines and hold the pile driver attachment in position during the pile driving operation.
[0004] Current skid-steer loaders including min-loaders have a limited range of attachments usually related to the form of bucket attached to the loader. It would be desirable to provide an attachment which is suitably for use with a range of different devices or tools or for use for a range of different purposes for example for the purpose of post driving, post pulling or post hole drilling.
SUMMARY OF THE INVENTION
[0005] The present invention aims to provide an attachment and in particular an hydraulic attachment which is particularly suited to use with a skid-steer loader and which may be used for a number of different purposes. The hydraulic attachment of the invention however may be used with other machinery such as other forms of loaders such as front end loaders or with or in association with other forms of vehicle. Other objects and advantages of the invention will become apparent from the following description.
[0006] The present invention thus provides in one aspect a hydraulic attachment adapted to be mounted to machinery or a vehicle such as earth working machinery, said attachment including a telescopic mast assembly, said mast assembly including a first lower mast member and at least one second upper mast member telescopically engaged with said lower mast member, at least one hydraulic actuator for extending or retracting said upper mast member relative to said lower mast member, mounting means for mounting said mast assembly to said machinery so as to be supported in use in a substantially upstanding attitude, and support means at the upper end of said mast assembly for supporting or carrying a tool.
[0007] The tool may comprise a post driver tool, an earth drilling tool or a post or tree extraction tool. Suitably the support means is adapted to support the tool such that the tool depends from the support means. The post driver tool for example may comprise reciprocative driving means for applying a reciprocative impact force to a post to be driven into the ground. Preferably the driving means comprise fluid driven driving means suitably pneumatic driving means. Preferably the driving means comprises a pneumatically reciprocative member which carries a weighted anvil or driving head.
[0008] The earth drilling tool may comprise an auger drivable by any suitable driving means for applying rotation to the auger. The driving means may comprise an hydraulic motor. The post or tree extraction tool may include means to grip a post or tree trunk such as hydraulically actuated jaws. Alternatively the post or tree extraction tool may simply comprise a chain which is wrapped around a post or tree and secured to the mast assembly.
[0009] Preferably the tools are detachably engageable with the support means. Preferably the upper ends of the tools are detachably engageable with the support means. Preferably the support means at the upper end of the mast assembly comprises an outwardly extending arm for supporting or carrying a tool. Preferably the respective tools are detachably engaged with the arm such that respective tools may be interchanged. If necessary the arm may be braced to the mast assembly. The mast assembly may have a foot at its lower end which may be engaged with the ground to stabilize the mast assembly in use. The foot may be adjustable from the lower end of the mast assembly for example by being telescopically extendable from the mast assembly. Preferably the foot comprises a planar member adapted to seat on a ground surface.
[0010] The mounting means is suitably provided on the side of the post assembly opposite the support means for the tool. The mounting means suitably includes a first part fixed to the mast assembly and a second part mountable to the machinery. The mounting means may include means for adjusting the upright attitude of the mast assembly in a transverse vertical plane. The first and second parts are preferably pivotally mounted to each other pivotal movement relative to each other about an axis extending substantially normal to the mast assembly which in use comprises a generally horizontal axis. The means for adjusting the upright attitude of the post assembly suitably comprises means for pivoting the second part relative to the first part. The means for pivoting the second part relative to the first part suitably comprises at least one actuator. The actuator suitably is provided between the second part and the mast assembly. The at least one actuator suitably comprises at least one hydraulic ram. Preferably the second part extends laterally of the post assembly. Preferably the second part extends laterally to opposite sides of the post assembly and a pair of hydraulic rams is provided, respective rams being located on opposite sides of the mast assembly and extending between the laterally extending portions of the second part and the mast assembly.
[0011] Means are suitably provided for holding the second part against, or in substantial juxtaposition with, the first part. The holding means suitably comprises at least one connector. The at least one connector suitably extends through at least one slot, suitably an arcuate slot in the first part which can accommodate limited pivotal movement of the first part relative to the second part. Preferably a pair of connectors are provided on opposite sides of the mast assembly and extend from the second part and through respective slots in the first part. Alternatively the second part may include at least one slot and at least one connector may extend from the first part and through the at least one arcuate slot in the second part. The connector or connectors suitable comprise bolts.
[0012] Preferably the second part includes coupling means for coupling to a complementary coupling means carried by the machinery. Preferably the coupling means carried by the second part and machinery comprise male-female coupling means. Preferably the coupling means comprises attachment means for releasably attaching the second part to the complementary coupling means carried by the machinery.
[0013] Preferably the second member of the mast assembly is received telescopically within the first member of the mast assembly. Preferably the second mast member is received non-rotatably within the first mast member. Preferably the first and second mast members comprise hollow sections preferably of a rectangular or square cross section, the sections being such that the second mast member has an external configuration of dimensions slightly less than the internal dimensions of the first mast member so as to be receivable in the first mast member for sliding movement relative thereto.
[0014] The mast assembly suitably also includes a third mast member telescopically received within the second mast member. Preferably the third mast member is received non-rotatably within the mast member. Preferably the third mast member comprises a hollow section preferably of a rectangular or square cross section with an external configuration of dimensions slightly less than the internal dimensions of the second mast member such that the third mast member is receivable in the second mast member for sliding movement relative thereto.
[0015] Preferably the support means for the tool such as an arm is rigidly connected to the third mast member. Preferably the arm extends substantially at right angles to the third mast member. Preferably means are provided to extend and retract the third mast member relative to the second mast member. Such means preferably comprise an hydraulic ram between the third mast member and second mast member. Preferably the hydraulic ram is connected between a bracket secured to the second mast member and third mast member. The bracket suitably comprises an elongated bracket secured at one end to the second mast member and extending longitudinally of the mast members and externally of the main mast member towards the normally lower end of the second and main mast members.
[0016] In a further aspect, the present invention comprises machinery or a vehicle having an attachment described above mounted thereto. The machinery suitably comprises hydraulically operated machinery such as earth working machinery. Preferably the earth working machinery comprises a skid-steer loader or front-end loader and the mounting means mounts the attachment to the loader.
[0017] According to a further aspect, the present invention provides an impact applying attachment adapted to be mounted to machinery such as earth working or loading machinery, said attachment including a telescopic mast assembly, mounting means for releasably mounting said post assembly to said machinery so as to be arranged in a substantially upstanding attitude, and support means from the upper end of said post assembly and extending therefrom, said support means carrying impact applying means.
[0018] Preferably the impact applying means depends from the support means. Suitably the impact applying means is provided on the side of the mast assembly opposite the mounting means. Preferably the impact applying means is associated with a weighted driving head or anvil.
[0019] The mast assembly and mounting means may be substantially of the same configuration as those described above.
[0020] Whilst the impact applying attachment is particularly designed for driving posts or piles into the ground, the attachment may also be used in other applications by replacing the anvil or driving head with another form of too). Thus the driving bead m may be replaced with a rock or concrete breaking head.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein:
[0022] FIG. 1 illustrates in side elevation a hydraulic attachment according to an embodiment of the invention supporting a post driver;
[0023] FIG. 2 is an opposite side elevation of the post driver of FIG. 1 ;
[0024] FIG. 3 is a partly cut-away sectional view of the mast assembly along line A-A of FIG. 1 (excluding the hydraulic extension rams);
[0025] FIG. 4 illustrates the attachment fitted to a skid-steer loader for driving a post into the ground;
[0026] FIG. 5 illustrates an auger assembly for mounting to the attachment;
[0027] FIG. 6 illustrates a post gripper for mounting to the attachment; and
[0028] FIG. 7 illustrates the manner in which a chain puller is used with the attachment for removing a post from the ground.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Referring to the drawings and firstly to FIGS. 1 to 3 , there is illustrated an attachment 10 typically for small size earth-working machinery according to an embodiment of the invention, the attachment 10 comprising an elongated telescopic mast assembly 11 comprising an outer elongated main hollow mast member 12 of square cross section, a second inner elongated hollow mast member 13 of complementary square cross section to and within the main mast member 12 and a third inner elongated hollow mast member 14 of complementary square cross section to and within the second inner hollow mast member 13 . The members 12 , 13 and 14 may thus be extended telescopically relative to each other to extend the length of the mast assembly 11 . Slides 10 ′ (shown in dotted outline in FIGS. 1 and 2 ) are provided within the upper ends of the main hollow member 12 and second inner hollow member 13 and at the lower end and on the outside of the second inner hollow member 13 and third inner hollow member 14 . The slides 10 ′ are provided on each of the faces of the respective members so as to occupy the space between the respective members 12 and 13 and 13 and 14 to facilitate smooth movement of the members 12 , 13 and 14 during telescopic extension and retraction of the post assembly 11 .
[0030] A first hydraulic ram 15 which extends longitudinally of the mast assembly 11 is mounted at opposite ends via mounting brackets 16 and 17 to a lower part of the main hollow member 12 and an upper part of the second member 13 respectively on one side of the mast assembly 11 . A second hydraulic ram 18 which also extends longitudinally of the mast assembly 11 is provided on the opposite side of the mast assembly 11 to the ram 15 and is mounted at its opposite ends 19 and 20 respectively to a bracket at an upper part of the third member 14 and a bracket 21 which is attached at 21 such as by welding to an upper part of the second member 13 , the bracket 21 being of a generally elongated U-shape configuration and extending from its attachment point 21 ′ downwardly along and on the outside of the mast assembly 11 towards a lower end of the main member 12 so that the lower end of the bracket 21 to which the lower end of the ram 18 is attached is free.
[0031] Extension of the first ram 15 will extend the second and third members 13 and 14 together and simultaneously from the main member 12 whist extension of the second ram 18 will extend the third member 14 from the second member 13 . Similarly retraction of the ram 18 will retract the third member 14 into the second member 13 and retraction of the ram 15 will retract the third member 14 and second member simultaneously into the main member 12 .
[0032] Extending substantially at right angles from and rigidly fixed to the third member 14 is a tool support in the form of a boom arm 22 . The boom arm 22 carries in this case an impact hammer 23 which is mounted at its upper end to the arm 22 to depend therefrom so as to be substantially parallel to the mast assembly 11 . The hammer 23 comprises a pneumatically driven impact hammer provided with a weighted impact head or anvil 24 . Pressurized air applied to the impact hammer 23 will cause reciprocation of the driving mechanism of the impact head 24 in a substantially vertical direction. Typically the impact hammer 23 comprises a rock breaker with the driving pin thereof being connected to the impact head 24 .
[0033] The attachment 10 additionally includes a mounting assembly 25 on the side of the mast assembly 11 opposite the arm 22 and impact hammer 23 for mounting the attachment 10 to a suitable prime mover. The mounting assembly 25 comprises a first plate 26 which is fixed rigidly to the main member 12 and extends laterally on opposite sides thereof and a second similar plate 27 which is pivotally mounted to the first plate 26 by a pivot pin 28 (shown in dotted outline) extending through aligned openings in the plates 26 and 27 whereby the plate 27 is mounted for rotation relative to the plate 26 about an axis extending normal to the longitudinal axis of the mast assembly 11 . The second plate 27 is retained to the first plate 26 by a pair of bolts 29 on opposite sides of the post assembly 11 , the bolts 29 passing through arcuate slots 30 in the first plate 26 which allow for limited pivotal movement of the second plate 27 and bolts 29 relative to the first plate 26 . The bolts 29 at the same time maintain the plates 26 and 27 in substantial face-to-face contact.
[0034] A pair of hydraulic rams 31 are provided on opposite sides of the mast assembly 10 respectively and extend between lugs 32 on the opposite outer sides of the second plate 27 and lugs 33 on opposite side of the main member 12 . Corresponding retraction and extension of the rams 31 on opposite sides of the mast assembly 11 will thus cause pivotal movement of the first plate 26 and thus mast assembly 11 relative to the second plate 27 in a transverse vertical plane as indicated by the arrows in FIG. 3 .
[0035] The second plate 27 also carries a coupling 34 to enable the attachment 10 to be mounted to a prime mover such as a stand-on mini skid-steer loader 35 (see FIG. 4 ). Thus a loader 35 provided with a complementary coupling 36 to the coupling 34 can engage and support the attachment 10 , the coupling 36 being provided at the end of link arms 37 of the loader 35 which can be hydraulically elevated or lowered. The coupling 36 is provided with spring-loaded pins 38 to enable positive connection between the couplings 34 and 36 when arranged in a mating complementary relationship with each other, the pins 38 being adapted to locate in corresponding holes 38 ′ in the coupling 34 .
[0036] When the attachment 10 is mounted to a loader 35 as in FIG. 4 and the attachment 10 is to be used to drive a fence post 39 or the like into the ground, the impact hammer 23 is mounted to the arm 22 and the loader 35 is used to position the mast assembly 11 adjacent to the post 39 and the ram and/or rams 15 and/or 18 are used to extend the mast assembly 11 and elevate the impact hammer 23 above the post 39 . The loader 35 can be manipulated towards and away from the post 39 so that the impact head 24 is substantially vertically above the post 39 . The hydraulic rams 31 are actuated if required to pivot the mast assembly 11 about a substantially horizontal axis as indicated by the arrows in FIG. 3 until it is in a substantially vertical position and hydraulic rams which are on the loader 35 and which control the arms 37 can also be adjusted to ensure that the mast assembly 10 is substantially upright. Pressurized air can then be applied to the impact hammer 23 so that the impact head 24 will reciprocate and apply an impact force to the upper end of the post 39 to drive it into the ground. As the post 39 is forced into the ground, the ram and/or rams 15 and/or 18 may be retracted to lower the boom arm 22 for example from the dotted outline position of FIG. 4 to maintain the impact hammer 23 in a position such that the impact head 24 will continued to apply an impact to the post 39 . This procedure is repeated until die post 39 is driven to the required depth into the ground.
[0037] Whilst in the embodiment shown in FIG. 4 , the mast assembly 10 is raised above the ground, the loader 35 can lower the mast assembly 10 onto the ground so that it is supported during the post driving operation. To support the mast assembly 10 , the lower end of the mast member 12 may be provided with a foot 40 shown in dotted outline in FIG. 4 which may comprise a flat plate for seating flat on the ground. The foot 40 may be mounted for telescopic extension from the mast assembly 10 .
[0038] All hydraulic fluid for supplying the rams 15 , 18 and 31 is supplied from the hydraulic supply of the loader 35 and under the control of hydraulic valves on the loader 35 controllable by the operator of the loader 35 . An auxiliary hydraulic supply however may be used to supply fluid to the rams.
[0039] The impact hammer 23 most suitably is detachable mounted to the arm 22 through a detachable coupling 41 which comprises complementary coupling parts on the arm 22 and hammer 23 . Thus the hammer 23 may be removed and replaced with other forms of tool for example an hydraulically operated auger assembly 42 as shown in FIG. 5 . The hydraulic attachment 10 may also carry a drilling device used for deep hole drilling where a series of drill rods may be interconnected one above the other. Thus the hydraulic attachment 10 carrying such a drilling device may be initially extended for attachment of the drilling rods to the drilling motor and then lowered to urge the drill rods into the ground. At the retracted position of the hydraulic attachment 10 , the drill rods may be disconnected from the drilling motor and the attachment 10 then extended to enable attachment of a further drill rods between the drilling motor and drill rod in the ground and the procedure repeated until the required depth is achieved.
[0040] Where the attachment 10 is to be used for extracting a member from the ground such as the post 39 , a post gripper 43 as shown in FIG. 6 may be attached to the arm 22 and lowered such that the jaws 44 of the gripper 43 can locate about the post 39 for gripping the post 39 (shown in dotted outline). For post extraction, to support the hydraulic attachment 10 , the member 12 is lowered by the loader 35 such that the foot 40 seats on the surface of the ground. Alternatively, the foot 40 may be extended from the lower end of the member 12 to engage the ground. The post gripper 43 may then be actuated such that the jaws 44 grip the post 39 after which the rams 18 and/or 15 may be extended to elevate the mast assembly 11 and arm 22 and extract the post 39 .
[0041] In a simplified arrangement, the attachment 10 may include one or more attachment points 45 to which a chain may be connected. Preferably and as illustrated in FIG. 7 , one attachment point 45 may be provided on top of the mast assembly and another attachment point 45 ′ at or adjacent the outer end of the arm 22 . For removal of a post 39 or other member in the ground such as a tree or tree stump, the chain 46 is wrapped around the post 39 or tree and secured to one or both attachment points 45 (an/or 45 ′). The attachment 10 may then again be elevated by means of the rams 15 and/or 18 such as to the position shown in dotted outline in FIG. 7 to lift the arm 22 and the chain 46 and thus lift the post 39 (or other member) from the ground.
[0042] Whilst the attachment 10 is shown and described in association with a mini skid-steer loader, it may be used with other forms of machinery such as earth working machinery or attached to a vehicle. Furthermore whilst the embodiment of FIG. 4 is described as a post driver, a substitute head may be used in place of the impact applying head 24 for other applications such as for jack hammer or rock breaking operations. Whilst the impact hammer 23 suitably comprises a pneumatically operated hammer, it may be any other form of impact applying tool such as a hydraulically operated hammer or tool.
[0043] It will also be appreciated that may different forms of tool may be coupled to the arm 22 through the complementary coupling 41 . The coupling 41 may be of many different configurations which will permit secure but releasable attachment of a tool to the arm 22 .
[0044] Where the hydraulic attachment 10 is to be used for post removal applications, it may not be necessary to include the mounting assembly 25 to provide for vertical adjustment of the attachment 10 .
[0045] It also may be desirable to brace the arm 22 in some applications and for this purpose a bracing member 47 shown in dotted outline in FIG. 1 may be provided between and connected to the arm 22 and member 14 . To accommodate movement of the member 14 relative to the member 12 and/or 13 , the members 12 and 13 are provided with longitudinally extending aligned slots 48 and 49 through which the bracing member 47 passes (see FIG. 3 ) for attachment to the member 14 .
[0046] The term “comprising” or “comprises” as used throughout the specification are taken to specify the presence of the stated features, integers and components referred to but not preclude the presence or addition of one or more other feature/s, integer/s, component/s or group thereof.
[0047] The above has been given by way of illustrative embodiment of the invention. It will be appreciated however that all variations and modifications to the invention as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as defined in the appended claims. | An hydraulic attachment ( 10 ) adapted to be mounted to machinery or a vehicle such as a skid-steer loader ( 35 ) and having a telescopic mast assembly ( 11 ) including a first lower mast member ( 12 ) and at least one second upper mast member ( 13 ) telescopically engaged with the lower mast member ( 12 ) and at least one hydraulic actuator ( 15 ) for extending or retracting the upper mast member ( 13 ) relative to the lower mast member ( 12 ). Mounting means ( 34 ) are provided for mounting the mast assembly ( 11 ) to the loader ( 35 ) so as to be supported in use in a substantially upstanding attitude and the mast assembly ( 12 ) includes support means ( 22 ) at its upper end for supporting or carrying a tool such as an impact applying tool ( 23 ). | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention is related to U.S. patent application Ser. No. 10/821,047, filed Apr. 8, 2004, entitled “AN INTERFACE CIRCUIT FOR COUPLING BETWEEN LOGIC CIRCUIT DOMAINS,”
[0002] U.S. patent application Ser. No. 10/821,048, filed Apr. 8, 2004, entitled “BUFFER/DRIVER CIRCUITS,” and
[0003] U.S. patent application Ser. No. 10/835,501, filed Apr. 29, 2004, entitled “SELF LIMITING GATE LEAKAGE DRIVER,” which are incorporated by reference herein.
GOVERNMENT RIGHTS
[0004] This invention was made with Government support under NBCH30390004 awarded by PERCS. The Government has certain rights in this invention.
TECHNICAL FIELD
[0005] The present invention relates in general to complementary metal oxide semiconductor (CMOS) circuits and, in particular, to circuit methodologies for implementing power-gating to control power and leakage.
BACKGROUND INFORMATION
[0006] Oxide tunneling current in metal oxide silicon (MOS) field effect transistors (FET) is a non-negligible component of power consumption as gate oxides get thinner, and may in the future become the dominant leakage mechanism in sub-100 nm complementary MOS (CMOS) circuits. The gate current is dependent on various conditions for a single transistor and three main static regions of operation may be identified for a MOSFET. The amount of gate-leakage current differs by several orders of magnitude from one region to another. Whether a transistor leaks significantly or not is also affected by its position in relation to other transistors within a CMOS circuit structure as this affects the voltage stress to which a particular device is subjected.
[0007] The three regions of operation are a function of applied bias if one only considers the parameters that affect the magnitude of gate current in a MOSFET as it operates in relation to other MOSFETs. Assuming that the supply voltage (Vdd) and the threshold voltage (Vt) are fixed, then a MOSFET in a static CMOS logic gate operates in one to the three regions, each with a significantly different amount of gate leakage.
[0008] The first region is called “strong inversion” and is the region where a MOSFET operates with the absolute value of the gate to source voltage (|VGS|) equal to Vdd. The gate-leakage current density for an N-channel FET (NFET) in strong inversion may be as high as 10 3 amperes square centimeter (A/cm 2 ) for an oxide thickness of 1.5 nanometers (nm) at Vdd equal to 3 volts (V). For such a thin oxide, a more realistic value for Vdd is 1.2 V, in which case the gate-leakage current would more likely be 20 A/cm 2 .
[0009] The second region is called the “threshold” region where |VGS|=Vt. A MOSFET operating in the threshold region will leak significantly less than one operating in the strong inversion region, typically 3 to 6 orders of magnitude less depending on Vdd and the oxide thickness.
[0010] The third region is called the “Off” region where |VGS|=0.0 V. For an NFET operating in the Off region, there is no leakage if the drain voltage (Vd)=0.0 V. However, if Vd is equal to Vdd, then a small leakage current in the reverse direction (drain to gate) may be present due to gate-drain overlap area. Of course this current depends on transistor geometry and is typically 10 orders of magnitude less than the gate-leakage current in the strong inversion region.
[0011] The above three regions represent three distinct conditions or states for the channel of a MOSFET. Whether an “ON” transistor operates at strong inversion or at threshold is determined by its position inside a logic circuit structure as well as by the state of other transistors in the circuit structure.
[0012] Both NFETs and P-channel FETs (PFETs) in a logic circuit structure operate in one of the three regions described above. However, the main tunneling current in a PFET device in strong inversion is due to hole tunneling from the valence band and the main tunneling current in an NFET device in strong inversion is due to electron tunneling from the conduction band. Because of this, PFET gate currents are about 10 times smaller than equivalent sized NFET devices. This fact is important in assessing gate-leakage in a static CMOS circuit.
[0013] Since gate leakage currents are measured as current density, it follows that the gate-leakage current in a MOSFET is directly proportional to the gate area (width times length). Transistor sizing, therefore, has a direct impact on the amount of gate-leakage in a CMOS logic circuit.
[0014] As CMOS circuits become smaller, leakage current that results when voltage is applied to the gate of the field effect transistors becomes a significant portion of the power dissipation. Leakage power may become the limiting factor in how small devices may be manufactured. As devices are made smaller, the power supply voltage is correspondingly reduced. However, this may not achieve an adequate reduction in leakage power dissipation. Alternate techniques are being employed to reduce leakage power. One popular technique is to use power-gating to isolate the power supply voltage in groups of circuits at controlled times. These circuits are sometimes referred to as being part of a power-gated domain. Other circuits may be evaluating a logic function and may not be in a power-gated domain. Interfacing between circuits in a power-gated domain and circuits in a non-power-gated domain may prove difficult. The state of an output from a power-gated domain may be uncertain during the time period of power-gating. While the benefits of power-gating are known, there is no consensus on strategies to preserve logic states of outputs in the power-gated domains. Since power-gated domains may be variable, the method of preserving output logic states from circuits in a power-gated domain are controlled by the power-gating control signals themselves.
[0015] The current drive capability of a CMOS buffer depends on the channel size of devices used to drive outputs or to drive many other logic gate inputs. Therefore, one would expect the large devices to exhibit large gate-leakage current when the technology has gate oxides that are very thin. Likewise, logic regions with a high number of logic gates may exhibit a large gate-leakage current due to the large number of devices that are in strong inversion at any one static time (between clock transitions). Logic regions with a high number of logic gates may employ power supply gating whereby the power to the logic devices are decoupled by the action MOSFETs, PFETs for the positive power supply voltage and NFETs for the negative power supply voltage. These regions where power supply gating is employed is sometimes referred to as “cuttable” regions. When a cuttable region is interfaced with a non-cuttable region, then logic states at the interface outputs may become indeterminate when power is decoupled.
[0016] Pipeline circuits are configured such that data proceeds from an input latch point through sequential circuits to an output latch point. Because data proceeds through the sequential circuits in a time sequence, it would be advantageous to partition the sequential circuits in a pipeline such that different levels of power-gating may be employed that would allow performance to be maintained while also allowing selected circuit partitions to be “shut-down” using power gating depending on the validity of the input data and when the circuits will be needed for a valid pipeline process.
[0017] There is, therefore, a need for a power-gating circuit to control selected power-gating devices coupled to partitions in a pipeline such that the partitions may be dynamically powered or shut-down to control leakage power dissipation while maintaining pipeline performance.
SUMMARY OF THE INVENTION
[0018] A pipeline circuit is partitioned and has a plurality of sequential power-gated regions between an input latch point and an output latch point. Since data proceeds from the input latch point through circuitry in time sequence, the first pipeline circuit partition (closest to the input latch point) is not power-gated as it would take too much time to charge the power rail if a signal indicating a valid pipeline process was received. The second pipeline circuit has power-gating devices that allow the power rail to be either fully ON or softly ON. Since leakage is proportional to the applied voltage, a power device may be applied to the rail that drops the voltage on the rail a threshold voltage below its normal value. The main power gating device would be OFF in this mode allowing the “soft” power-gating to reduce leakage while allowing fast turn-ON of the power rail in the event a valid signal is received. The third pipeline circuit has complete power-gating that allows the power rail to be completely shut OFF. Since the third pipeline circuit has more time to turn ON, it can be fully power-gated. Latching circuitry may be employed on the valid signal to ensure the valid state is maintained. In one embodiment, the soft power gating device is controlled by a control signal from the power-gating control circuit. In another embodiment, the soft power-gating device is self-biased ON all the time. Registers are employed between the partitions to hold data during periods of power-gating where outputs of power-gated logic may have indeterminate outputs.
[0019] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
[0021] FIG. 1 is a circuit block diagram illustrating a basic topology of embodiments of the present invention for power-gating a virtual ground rail;
[0022] FIG. 2 is a circuit block diagram illustrating a basic topology of embodiments of the present invention for power-gating a virtual positive voltage rail;
[0023] FIG. 3 is a circuit block diagram of pipeline power-gating according to embodiments of the present invention;
[0024] FIG. 4 is a circuit block diagram of pipeline power-gating according to another embodiment of the present invention;
[0025] FIG. 5 is a circuit block diagram of pipeline power-gating according to another embodiment of the present invention; and
[0026] FIG. 6 is a data processing system suitable for practicing embodiments of the present invention.
DETAILED DESCRIPTION
[0027] In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. In other instances, well-known circuits may be shown in block diagram form in order not to obscure the present invention in unnecessary detail. For the most part, details concerning timing, and the like have been omitted inasmuch as such details are not necessary to obtain a complete understanding of the present invention and are within the skills of persons of ordinary skill in the relevant art.
[0028] In the following, power supply voltage potentials are distributed to circuits on circuit traces or printed wires which may be referred to interchangeably as power supply rails, grids or buses. Power supply voltage potentials are coupled to the buses or grids to activate various logic circuitry. The power supply voltage potentials may be referred to simply as positive potential or ground potential. The “voltage” term may be dropped for simplicity with the understanding that all the potentials are voltage potentials. Embodiments of the present invention employ power-gating circuitry for generating “virtual” power supply rails (power rails) where switching devices couple and decouple the power rails from the power supply potential. The term virtual may be dropped to simplify circuit descriptions.
[0029] Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.
[0030] FIG. 1 is a block circuit diagram of power-gating according to embodiments of the present invention. A logic circuit domain 101 has a virtual low (ground) power supply rail or bus (VGR) 103 that is coupled to the ground nodes 130 - 132 of selected circuits 110 , 111 , and 113 in domain 101 . Logic circuit 113 illustrates the FETs making up its logic function. Power supply 115 has positive voltage potential 116 coupled directly to bus 112 and ground voltage potential 117 . The VGR 103 is selectively coupled to the power supply ground voltage potential 117 with parallel N channel field effect transistor (NFET) devices 105 , 107 , and 109 operating as electronic switches. NFETs 105 , 107 , and 109 have nodes 150 - 152 , respectively, coupled to VGR 103 and nodes 153 - 154 , respectively, coupled to ground voltage potential 117 . The NFETs 105 , 107 , and 109 are controlled by logic signals 104 , 106 , and 108 , respectively. Logic signals 104 , 106 , and 108 are generated in logic domain 102 with non power-gated circuitry. In this manner, VGR 103 may be coupled to ground potential 117 with various degrees of conductivity.: Large devices have higher conductivity but generally display higher leakage. Smaller devices have lower conductivity but display lower leakage. In this manner, some or all of parallel connected NFETs 105 , 107 , and 109 may be gated ON when there is a high degree of switching in domain 101 requiring speed in arriving at a logic output in response to logic inputs. Once an output is determined in domain 101 , selective ones of NFETs 105 , 107 , and 109 may be gated OFF thus reducing leakage power.
[0031] FIG. 2 is a block circuit diagram of power-gating according to embodiments of the present invention. A logic circuit domain 201 has a virtual high (positive) power supply rail or bus (VPR) 203 that is coupled to a positive power bus in selected circuits 210 . Ground bus 211 of logic gates 210 is coupled directly to ground potential 117 of power supply 115 . VPR 203 is coupled to the positive potential 116 of power supply with parallel P channel field effect transistor (PFET) devices 205 , 207 , and 209 operating as electronic switches. PFETs 205 , 207 , and 209 have nodes 252 - 254 , respectively, coupled to positive voltage potential 116 and nodes 250 - 251 , respectively, coupled to VPR 203 . The PFETs 205 , 207 , and 209 are gated by logic signals 204 , 206 , and 208 , respectively. Logic signals 204 , 206 , and 208 are generated in logic domain 202 with non-power-gated circuitry. In this manner, VPR 203 may be coupled to the positive potential 116 with various degrees of conductivity. Large devices have higher conductivity but display higher leakage. Smaller devices have lower conductivity but display lower leakage. Some or all of PFETs 205 , 207 , and 209 may be gated ON when there is a high degree of switching in domain 201 requiring speed in arriving at a logic output in response to logic inputs. Once an output is determined in domain 201 , selective ones of PFETs 205 , 207 , and 209 may be gated OFF thus reducing leakage power.
[0032] FIGS. 1 and 2 show partitioned power-gating applied to only one power supply potential at a time, however, it is understood that embodiments of the present invention may employ partitioned power-gating simultaneously to both power supply potentials for logic circuits in a logic domain (e.g., domain 201 ).
[0033] The following FIGS. 3-5 show embodiments of the present invention applied to one power supply bus at a time for simplicity. Likewise, NFETs and PFETs are used as electronic switches to couple power supply potentials to virtual power buses. These NFETs and PFETs have nodes that may not have specific designators as used in FIGS. 1 and 2 for simplicity of the drawings.
[0034] FIG. 3 is a circuit block diagram of pipeline power-gating 300 according to embodiments of the present invention. Data 313 is latched into register 314 by clock 312 . Processing of data 313 proceeds through the pipeline stage 320 comprising partitions A, B, and C. Partitions A, B, and C are not internally clocked but process data in a ripple through mode. In this embodiment, only the input and output of pipeline stage 320 are clocked. Finally the processed data 313 is latched into register 318 with clock 312 . Pipeline 320 is partitioned to allow power-gating according to embodiments of the present invention. It is obvious that logic in partition A processes data 313 before partition B and likewise partition B is needed to process the output of partition A before partition C. Since partition A must act on data 313 first, its logic is not power gated. Partition B has a power bus 323 that is power gated by the action of PFET 305 and NFET 308 and partition C has power bus 324 that is power-gated by PFET 309 .
[0035] Power gating control 302 receives a valid signal 301 which indicates if the data 313 is valid and can be launched into pipeline stage 320 . Partition A can begin processing data 313 immediately upon receipt of a valid signal 301 as its power buses are not power gated. Since there is some time before partition B is needed, its power bus 323 has two levels of power-gating. Since there is not much time to charge its power bus 323 , NFET 308 acts as a soft power-gate. When NFET 308 is turned ON by a logic one on control 307 , it sets bus 323 at a threshold voltage (Vt) below the voltage potential of power rail 326 . Keeping power rail 323 at a slightly lower voltage potential improves leakage while allowing power rail 323 to be quickly charged to the power supply voltage potential when PFET 305 is turned ON by a logic zero on control 304 . In this embodiment, control 307 transitions to a logic one before control 304 transitions to a logic one. Partition C is needed last and more time is available to charge power rail 324 from a lower voltage potential so power rail 324 is fully power-gated. Feedback signals 306 and 310 are used to signal power gating control 302 that partition B 316 and partition C 317 have completed processing and may set to their appropriate power-gating states.
[0036] FIG. 4 is a circuit block diagram of pipeline power-gating 400 according to another embodiment of the present invention. Data 413 is latched into register 414 by clock 412 . Processing of data 413 proceeds through the pipeline stage 420 comprising partition A, B, and C and registers 421 and 422 . Registers 422 and 421 are used to hold outputs of partitions A and B. Partitions A, B, and C are not internally clocked but each process data in a ripple through mode. In this embodiment, only the inputs and outputs of the partitions A, B, and C are clocked. Finally the processed data 413 is latched into register 418 with clock 412 . Pipeline 420 is partitioned to allow power-gating according to embodiments of the present invention. It is obvious that logic in partition A processes data 413 before partition B and likewise partition B is needed to process the output of partition A before partition C. Since partition A must act on data 413 first, its logic is not power gated. Partition B has a power bus 423 that is power gated by the action of PFET 405 and NFET 408 and partition C has power bus 424 that is power-gated by PFET 409 .
[0037] Power gating control 402 receives a valid signal 401 which indicates if the data 413 is valid and can be launched into pipeline stage 420 . Partition A 415 can begin processing data 413 immediately upon receipt of a valid signal 401 as its power buses are not power gated. Since there is some time before partition B 416 is needed, its power bus 423 has two levels of power-gating. Since there is not much time to charge its power bus 423 , NFET 408 acts as a soft power-gate. When NFET 408 is turned ON by a logic one on control 407 , it sets bus 423 at a threshold voltage (Vt) below the voltage potential of power rail 426 . Keeping power rail 423 at a slightly lower voltage potential improves leakage while allowing power rail 423 to be quickly charged to the power supply voltage potential when PFET 405 is turned ON by a logic zero on control 404 . Once processed data has been latched into register 421 , partition B, 416 can be power-gated knowing that the output states are latched into a non power-gated register. In this embodiment, control 407 transitions to a logic one before control 404 transitions to a logic one. Partition C 417 is needed last and more time is available to charge power rail 424 from a lower voltage potential so power rail 424 is fully power-gated. Likewise, once the data from partition C 417 has been latched in to register 418 , it can be fully power-gated. Feedback signals 406 and 410 are used to signal power gating control 402 that partition B 416 and partition C 417 have completed processing and may set to their appropriate power-gating states.
[0038] FIG. 5 is a circuit block diagram of pipeline power-gating 500 according to another embodiment of the present invention. Data 513 is latched into register 514 by clock 512 . Processing of data 513 proceeds through the pipeline stage 520 comprising partition A, B, and C and registers 521 and 522 . Registers 522 and 521 are used to hold outputs of partitions A and B. Partitions A, B, and C are not internally clocked but each process data in a ripple through mode. In this embodiment, only the inputs and outputs of the partitions A, B, and C are clocked. Finally the processed data 513 is latched into register 518 with clock 512 . Pipeline 520 is partitioned to allow power-gating according to embodiments of the present invention. It is obvious that logic in partition A processes data 513 before partition B and likewise partition B is needed to process the output of partition A before partition C. Since partition A must act on data 513 first, its logic is not power gated. Partition B has a power bus 523 that is power gated by the action of PFET 505 and NFET 508 and partition C has power bus 524 that is power-gated by PFET 509 .
[0039] Power gating control 502 receives a valid signal 501 which indicates if the data 513 is valid and can be launched into pipeline stage 520 . Partition A 515 can begin processing data 513 immediately upon receipt of a valid signal 501 as its power buses are not power gated. Since there is some time before partition B 516 is needed, its power bus 523 has two levels of power-gating. Since there is not much time to charge its power bus 523 , NFET 508 acts as a soft power-gate that is self biased ON all the time. NFET 508 is always on and it sets bus 523 at a threshold voltage (Vt) below the voltage potential of power rail 526 when PFET 505 is turned OFF by a logic one on control 504 . Keeping power rail 523 at a slightly lower voltage potential improves leakage while allowing power rail 523 to be quickly charged to the power supply voltage potential when PFET 505 is turned ON by a logic zero on control 504 . Once processed data has been latched into register 521 , partition B 516 can be power-gated knowing that the output states are latched into a non power-gated register. Partition C 517 is needed last and more time is available to charge power rail 524 from a lower voltage potential so power rail 524 is fully power-gated by PFET 509 which also is controlled by control 504 . Likewise, once the data from partition C 517 has been latched in to register 518 , it can be fully power-gated.
[0040] When Valid 533 is a logic one and Clk 512 transitions to a logic one, NFETs 531 and 532 turn ON pulling the input to inverter 502 to a logic zero and the output of inverter 503 to a logic zero turning ON both PFET 505 and 509 thereby charging power rails 523 and 524 to full power supply potential. Since power rail 524 may be fully discharged it takes longer to charge. When Clk 512 transitions to a logic zero, it turns ON PFET 530 and pulls input of inverter 502 to a logic one causing its output to transition to a logic zero turning ON keeper PFET 501 which latches the logic one state at the input of inverter 502 and at the output of inverter 503 . This turns OFF both PFET 505 and PFET 509 . Power rail 523 is soft power-gated as NFET 508 is biased ON setting power rail 523 at threshold voltage Vt below the full power supply potential at power rail 526 and power rail 524 is turned fully OFF.
[0041] FIG. 6 is a high level functional block diagram of a representative data processing system 600 suitable for practicing the principles of the present invention. Data processing system 600 includes a central processing system (CPU) 610 operating in conjunction with a system bus 612 . System bus 612 operates in accordance with a standard bus protocol, such as the ISA protocol, compatible with CPU 610 . CPU 610 operates in conjunction with electronically erasable programmable read-only memory (EEPROM) 616 and random access memory (RAM) 614 . Among other things, EEPROM 616 supports storage of the Basic Input Output System (BIOS) data and recovery code. RAM 614 includes DRAM (Dynamic Random Access Memory) system memory and SRAM (Static Random Access Memory) external cache. I/O Adapter 618 allows for an interconnection between the devices on system bus 612 and external peripherals, such as mass storage devices (e.g., a hard drive, floppy drive or CD/ROM drive), or a printer 640 . A peripheral device 620 is, for example, coupled to a peripheral control interface (PCI) bus, and 110 adapter 618 therefore may be a PCI bus bridge. User interface adapter 622 couples various user input devices, such as a keyboard 624 or mouse 626 to the processing devices on bus 612 . Display 638 which may be, for example, a cathode ray tube (CRT), liquid crystal display (LCD) or similar conventional display units. Display adapter 636 may include, among other things, a conventional display controller and frame buffer memory. Data processing system 600 may be selectively coupled to a computer or telecommunications network 641 through communications adapter 634 . Communications adapter 634 may include, for example, a modem for connection to a telecom network and/or hardware and software for connecting to a computer network such as a local area network (LAN) or a wide area network (WAN). CPU 610 and other components of data processing system 600 may contain pipeline circuitry that is pipeline power-gated according to embodiments of the present invention to manage leakage current and thus leakage power. | A low power consumption pipeline circuit architecture has power partitioned pipeline stages. The first pipeline stage is non-power-gated for fast response in processing input data after receipt of a valid data signal. A power-gated second pipeline stage has two power-gated modes. Normally the power rail in the power-gated second pipeline stage is charged to a first voltage potential of a pipeline power supply. In the first power gated mode, the power rail is charged to a threshold voltage below the first voltage potential to reduce leakage. In the second power gated mode. the power rail is decoupled from the first voltage potential. A power-gated third pipeline stage has its power rail either coupled to the first voltage potential or power-gated where its power rail is decoupled from the first voltage potential. The power rail of the second power-gated pipeline stage charges to the first voltage potential before the third power-gated pipeline stage. | 6 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional application no. 60/895,152, filed Mar. 16, 2007, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to an integrated fan powered silencing terminal unit for HVAC (heating, ventilating, and air conditioning) systems.
BACKGROUND OF THE INVENTION
[0003] Commercial HVAC systems have contained “Fan Powered Terminal Units” (“FPTUs”) for the purpose of providing an outlet for commercial ventilation systems into the rooms of a building or other structure equipped with an HVAC system. A FPTU typically consists of the following components: 1) centrifugal fan, 2) motor, 3) insulated casing, and 4) air inlet (with or without damper).
[0004] In commercial HVAC installations, a “silencer” (or “attenuator”) is often attached to the inlet or outlet of an FPTU in order to attenuate the sound produced by the high-velocity air entering the FPTU. Such silencers have typically comprised an air duct (typically from three to five feet in length) that is lined internally with insulation to attenuate the noise produced by the air flowing through the FPTU. Such internal insulation is also known as a “baffle” and is usually held in place by perforated sheet metal. The perforations in the metal allow the air traveling through the silencer to interact with the insulation material contained inside the baffle. The silencer is attached to the inlet or the outlet of the FPTU and acts to attenuate the noise that is produced by the FPTU. This attenuation is achieved due to the conversion of acoustic energy into heat energy as the air molecules inside the silencer create friction when they collide with the lined insulation.
[0005] The noise generated by an FPTU can be separated into two components: 1) noise due to the air disturbance created in the immediate vicinity of the rotating fan blades and 2) aerodynamic noise due to the fan-induced air flow that has variable pressure regions within the fan discharge velocity profile and the air flow interaction with geometry changes in the air stream. The insulation contained in silencers minimizes both sources of noise created by the FPTU.
[0006] The noise generated by a given FPTU can vary widely depending on how it is utilized in a particular HVAC system and on the configuration of the HVAC system. Similarly, the acoustic performance of a given silencer can also vary widely depending upon the configuration of the HVAC system in which it is installed. Such unpredictability of the noise that will be generated by an FPTU and the attenuation achieved by a silencer is known as the “system effect” of the HVAC system in which the FPTU and silencer are installed. For instance, the manner in which the distribution ductwork is organized in a given building installation can affect the turbulence and air pressures created inside the ductwork. This, in turn, can affect the noise level generated by an FPTU and the acoustic performance achieved by a silencer attached thereto.
[0007] The unpredictability produced by such system effects creates uncertainty when HVAC installers are selecting FPTUs and silencers for installation in a building. Manufacturers of traditional FPTUs and silencers typically test their products under artificial laboratory conditions and produce specifications as to the noise generated by their FPTUs and the noise attenuation achieved by their silencers. However, these specifications do not take into account the system effects produced by installing their products in an actual HVAC system. Thus, HVAC installers generally have only marginally reliable product specifications on which they can rely and often must utilize trial-and-error methods to choose the appropriate combination of FPTUs and silencers that will meet their needs in a particular HVAC installation.
SUMMARY OF THE INVENTION
[0008] The invention (a fan powered silencing terminal unit “FPSTU”) involves an apparatus and method for attenuating the sound generated by a fan powered terminal unit in a predictable and consistent manner. A further object of the invention is the integration of an FPTU and a silencer into a single unit. Another object of the invention is to attenuate sound to a greater degree than is possible with a combination of prior art FPTUs or silencers of a given size.
[0009] Embodiments of the invention can minimize the noise generated by the variable pressure regions within the FPSTU unit by closely coupling the noise-attenuating, insulation-lined silencing portion of the unit to the housing of the centrifugal fan inside the unit. Such close-coupling minimizes the turbulence created by the centrifugal fan and thus minimizes the associated noise.
[0010] Embodiments of the invention also minimize noise within the FPSTU by creating a constant, uniform cross-sectional profile of the air traveling through the unit. This uniform cross-sectional profile minimizes the turbulence created when air exiting a typical FPTU enters a silencer with a larger (or smaller) cross-sectional area. The decreased turbulence in the airflow of the invention, in turn, helps minimize the noise generated by the FPSTU.
[0011] Embodiments of the invention minimize high-frequency noise due to the internal angled or curved geometry of the FPSTU. Such geometry obstructs any direct line-of-sight pathway out of the unit that would otherwise allow high-frequency noise to escape without much attenuation. Traditional silencers lack any such internal geometry and instead allow high-frequency noise to exit the silencer without contacting the baffles of the silencer. Therefore, the high-frequency noise in a traditional silencer can escape without much attenuation.
[0012] Further objects, features, and advantages will become apparent upon consideration of the following detailed description of the invention when taken in conjunction with the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a side elevation view of a centrifugal fan and the velocity and pressure profile of the air leaving the centrifugal fan in a prior art FPTU.
[0014] FIG. 2A is a top cut away view of a prior art FPTU coupled to a prior art silencer with vertical baffles.
[0015] FIG. 2B is a side cross-sectional view of a prior art FPTU coupled to a prior art silencer with horizontal baffles.
[0016] FIG. 3A is a top cut away view of a prior art FPTU coupled to a prior art silencer.
[0017] FIG. 3B is a side cross-sectional view of FIG. 3A .
[0018] FIG. 3C is an end view along line 3 C of FIG. 3B .
[0019] FIG. 3D is a cross-sectional view along line 3 D of FIG. 3B .
[0020] FIG. 4A is a top cut away view of an embodiment of an FPSTU in accordance with the invention.
[0021] FIG. 4B is a side cross-sectional view of FIG. 4A .
[0022] FIG. 4C is an end view along line 4 C of FIG. 4B .
[0023] FIG. 4D is a cross-sectional view along line 4 D of FIG. 4B .
[0024] FIG. 4E is a magnified cross-sectional view of inset 4 E of FIG. 4B .
[0025] FIG. 5A is a top cut away view of an embodiment of an FPSTU in accordance with the invention.
[0026] FIG. 5B is a side cross-sectional view of FIG. 5A .
[0027] FIG. 5C is an end view along line 5 C of FIG. 5B .
[0028] FIG. 5D is a cross-sectional view along line 5 D of FIG. 5B .
[0029] FIG. 5E is a magnified cross-sectional view of inset 5 E of FIG. 5B .
[0030] FIG. 6A is a top cut away view of an embodiment of an FPSTU in accordance with the invention.
[0031] FIG. 6B is a side cross-sectional view of FIG. 6A .
[0032] FIG. 6C is an end view along line 6 C of FIG. 6B .
[0033] FIG. 6D is a cross-sectional view along line 6 D of FIG. 6B .
[0034] FIG. 6E is a magnified cross-sectional view of inset 6 E of FIG. 6B .
[0035] FIG. 7A is a top cut away view of an embodiment of an FPSTU in accordance with the invention.
[0036] FIG. 7B is a side cross-sectional view of FIG. 7A .
[0037] FIG. 7C is an end view along line 7 C of FIG. 7B .
[0038] FIG. 7D is a cross-sectional view along line 7 D of FIG. 7B .
[0039] FIG. 7E is a magnified cross-sectional view of inset 7 E of FIG. 7B .
DETAILED DESCRIPTION
[0040] FIG. 1 is an illustration of the velocity and pressure profile of a centrifugal fan 101 in a typical prior art FPTU 100 . The centrifugal fan 101 is enclosed in a housing 103 and blows air out into a discharge duct 102 or attached silencer. The housing 103 of the fan 101 has a cutoff plate 104 on the lower edge of the housing 103 . The cutoff plate 104 creates a low pressure area 105 immediately behind the cutoff plate 104 . The high-velocity air exiting the fan 101 exhibits a non-uniform bulge 106 of high pressure. As the air travels down the discharge duct 102 , the bulge of high pressure will gradually even out as illustrated in 107 , 108 , 109 , and 110 . The turbulence generated as the high pressure bulge gradually evens out will create noise in the FPTU 100 .
[0041] FIGS. 2A and 2B are illustrations of the close-coupling of a prior art FPTU 201 with a prior art silencer 202 . Such silencers typically have vertical baffles 203 a or horizontal baffles 203 b (with respect to the FPTU 201 ) in order to attenuate the sound produced by the FPTU 201 . Prior art silencers 202 typically have a wider cross-sectional area than a corresponding FPTU 201 , creating a wide area 204 inside the silencer 202 . This wide area 204 creates a space where turbulence can develop in the silencer 202 , thus unnecessarily increasing the noise level in the silencer 202 . In addition, prior art FPTUs 201 contain the cutoff plate 205 described previously, which also increases the noise generated by the FPTU 201 due to the non-uniform bulge of high pressure exiting the FPTU 201 . The cross-sectional area of the blower outlet 210 of prior art FPTUs 201 is typically larger than the cross-sectional area of the air pathway 206 of prior art silencers 202 . Therefore a “nose” 209 is created where the air exiting the blower outlet 210 collides into the baffles 203 a , 203 b inside the silencer 202 . This causes added turbulence and increased noise.
[0042] Prior art FPTUs 201 and silencers 202 also have a direct line-of-sight pathway 206 from the centrifugal fan 207 of the FPTU 201 to the discharge outlet 208 of the silencer 202 . As a consequence of such a direct line-of-sight pathway 206 , high-frequency sounds can travel relatively unobstructed through the silencer 202 . This is because the shorter wavelengths of high-frequency sound waves produce less displacement of the air molecules and hence those air molecules are less likely to collide with the baffles 203 a , 203 b inside the silencer 202 . This “beaming” effect of high-frequency sounds thus reduces the effectiveness of prior art silencers 202 in reducing high-frequency noise.
[0043] FIGS. 3A-3D are depictions of a prior art FPTU 301 closely-coupled to a prior art silencer 304 with only a half-baffle design. That is, the silencer 304 contains a baffle 306 on only a single internal wall. This half-baffle silencer 304 still contains a nose 302 which leads to increased turbulence and noise. The nose 302 is caused because the cross-sectional air pathway 305 of the silencer 304 is narrower than the cross-sectional area of the blower outlet 303 of the FPTU 301 .
[0044] FIG. 3C depicts an end view of the silencer 304 and the perforated metal casing 353 that encloses the insulating material 354 of the baffle 306 . FIG. 3C also shows the casing 351 of the silencer 304 and the casing 352 of the FPTU 301 .
[0045] FIG. 3D depicts a cross-sectional view of the insulating material 354 that comprises the baffle 306 of the silencer 304 . FIG. 3D also shows the casing 351 of the silencer 304 and the casing 352 of the FPTU 301 .
[0046] FIGS. 4A-4E depict an embodiment of an FPSTU 401 in accordance with the invention. FPSTU 401 contains a silencer inlet extension 402 which connects the top edge 403 of the baffle 409 contained in the silencing portion 404 of the FPSTU 401 directly to the cutoff plate 405 of the centrifugal fan 406 housed in the FPSTU 401 . The silencer inlet extension 402 eliminates the low-pressure area 105 caused by the cutoff plate 104 in prior art FPTUs ( FIG. 1 ). Therefore, the air exiting the centrifugal fan 406 does not contain a non-uniform bulge of high pressure as it travels down the air pathway 407 of the silencing portion 404 of the FPSTU 401 .
[0047] In addition, the cross-sectional area of the blower outlet 408 substantially equals the cross-sectional area of the air pathway 407 of the silencing portion 404 of the FPSTU 401 . Therefore, the FPSTU 401 contains no nose, unlike the nose 209 , 302 present in prior art silencers 202 , 304 ( FIGS. 2B , 3 B).
[0048] FIG. 4C depicts an end view of the FPSTU 401 and the perforated metal casing 453 that encloses the insulating material 454 of the baffle 409 . FIG. 4C also shows the casing 451 of the silencing portion 404 of the FPSTU 401 and the casing 452 of the plenum portion of the FPSTU 401 .
[0049] FIG. 4D depicts a cross-sectional view of the insulating material 454 that comprises the baffle 409 of the silencing portion 404 of the FPSTU 401 . FIG. 4D also shows the casing 451 of the silencing portion 404 of the FPSTU 401 and the casing 452 of the plenum portion of the FPSTU 401 .
[0050] FIGS. 5A-5E illustrate an embodiment of the invention wherein the baffle 502 of the silencing portion 503 of the FPSTU 501 flares outward in a “tail” 504 . This tail 504 allows the expanding air that is traveling down the air pathway 505 to maintain a constant pressure. This is because the increased cross-sectional area of the tail portion 504 of the FPSTU 501 provides additional space for the expanding air to occupy, thus preventing a buildup of pressure within the FPSTU 501 .
[0051] FIG. 5C depicts an end view of the FPSTU 501 and the perforated metal casing 553 that encloses the insulating material 554 of the baffle 502 . FIG. 5C also shows the casing 551 of the silencing portion 503 of the FPSTU 501 and the casing 552 of the plenum portion of the FPSTU 501 .
[0052] FIG. 5D depicts a cross-sectional view of the insulating material 554 that comprises the baffle 502 of the silencing portion 503 of the FPSTU 501 . FIG. 5D also shows the casing 551 of the silencing portion 503 of the FPSTU 501 and the casing 552 of the plenum portion of the FPSTU 501 .
[0053] FIGS. 6A-6E illustrate an embodiment of the invention with a high-frequency splitter 602 placed in the air pathway 603 of the FPSTU 601 . The high-frequency splitter 602 scatters high-frequency sound waves that would otherwise pass relatively unobstructed through the air pathway 603 due to the “beaming” effect of high-frequency sound. The scattered high-frequency sound waves will therefore tend to impact the baffle 605 directly or bounce off the casing 604 and then into the baffle 605 , which will attenuate the sound.
[0054] FIG. 6C depicts an end view of the FPSTU 601 and the perforated metal casing 653 that encloses the insulating material 654 of the baffle 605 . FIG. 6C also shows an end view of the high-frequency splitter 602 . FIG. 6C also shows the casing 651 of the silencing portion of the FPSTU 601 and the casing 652 of the plenum portion of the FPSTU 601 .
[0055] FIG. 6D depicts a cross-sectional view of the insulating material 654 that comprises the baffle 605 of the silencing portion of the FPSTU 601 . FIG. 6D also shows the casing 651 of the silencing portion of the FPSTU 601 and the casing 652 of the plenum portion of the FPSTU 601 .
[0056] FIGS. 7A-7E depict an embodiment of the invention wherein the air pathway 702 of the FPSTU 701 is angled or curved, thus minimizing or eliminating the line-of-sight pathway from the centrifugal fan 703 to the discharge outlet of the FPSTU 701 . This elimination of the line-of-sight pathway will likewise minimize the high-frequency noise emitted by the centrifugal fan 703 and prevent high-frequency sound waves from traveling down the air pathway 702 unobstructed. The silencing portion of the FPSTU 701 can be up to five feet in length with an optimal length of three feet or less.
[0057] FIG. 7C depicts an end view of the FPSTU 701 and the perforated metal casing 753 that encloses the insulating material 754 of the angled top baffle 704 . FIG. 7C also shows the casing 751 of the silencing portion of the FPSTU 701 and the casing 752 of the plenum portion of the FPSTU 701 .
[0058] FIG. 7D depicts a cross-sectional view of the insulating material 754 that comprises the top and bottom baffles 704 , 705 of the silencing portion of the FPSTU 701 . FIG. 7D also shows the casing 751 of the silencing portion of the FPSTU 701 and the casing 752 of the plenum portion of the FPSTU 701 .
[0059] While this invention has been described with reference to the structures and processed disclosed, it is to be understood that variations and modifications can be affected within the spirit and scope of the invention as described herein and as described in the appended claims. | An apparatus and method for attenuating the sound generated by a fan powered terminal unit in an HVAC (heating, ventilating, and air conditioning) system. The apparatus utilizes internal geometry to minimize noise due to air disturbances and aerodynamic effects within the apparatus. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a firing mechanism for a subterranean well perforating gun which may be installed in the wall either with the perforating gun, or subsequent to the placement of the perforating gun in the well, and, in the event that the firing mechanism does not function, can be retrieved from the well and replaced by another firing mechanism in order to effect the firing of the gun.
2. History of the Prior Art
In the completion of modern subterranean wells of substantial depth, it has become a common practice to employ a perforating gun that is run into the well on the bottom of a tubing string. A packer is incorporated in the tubing string and is set in the well casing so as to position the perforating gun adjacent the production formation. This practice has the advantage of permitting a much larger perforating gun to be employed than is possible if the gun were run into the well through a tubing string on a wireline. More importantly, it permits the perforating of the well in the so-called "underbalanced" condition wherein the fluid pressure existing in the tubing string adjacent the formation is substantially less than the anticipated fluid pressure of the production formation after the perforating operation is completed. This permits a relatively high velocity flow of production fluid from the newly formed perforations into the tubing string, thus flushing the perforations of the debris that is commonly associated with the perforating operation.
One negative factor encountered in the mounting of a perforating gun on the bottom of the tubing string is the high cost involved in replacing the gun in the event the gun fails to fire. Obviously, the entire tubing string must be withdrawn from the well, the firing mechanism for the perforating gun repaired or replaced, and then the perforating gun again run into the well on a newly formed tubing string. In a deep well this involved a delay of many hours in completing the well.
There is, therefore, a definitive need for a retrievable and replaceable firing mechanism for a tubing carried perforating gun which may be retrieved from the well and replaced by wireline in the event that the firing mechanism fails to operate.
SUMMARY OF THE INVENTION
The invention provides a replaceable firing mechanism for a tubing carried perforating gun which is installed in a subterranean well at a desired location by the setting of a packer incorporated in the tubing string. The firing mechanism for the perforating gun comprises two axially aligned hollow housings. The lower housing has a thin walled solid upper end and contains a conventional booster charge and a primer cord which extends from the booster charge to each of the shaped charges conventionally mounted in vertically and angularly spaced relationship in the perforating gun. The second or upper hollow housing element of the firing mechanism has a thin walled solid bottom portion which is normally disposed in abutting or closely adjacent relationship to the solid top end portion of the first mentioned or lower hollow housing. The upper housing element contains an impact detonatable primer and a downwardly directed shaped charge which is disposed between the primer and the solid bottom end wall of the upper hollow housing. The upper open end of the upper hollow housing is partially closed by an annular hammer support sleeve. A hammer is slidably mounted within the support sleeve and is relatively movable with respect to the primer, which is fixedly mounted within the housing, from a remote or upwardly spaced position to a contiguous position. Such movement of the hammer is produced by a wireline engagable member, similar to a fishing neck, which is secured to the hammer. An outer sleeve is also secured to the wireline engagable member and projects downwardly in surrounding relationship to both the upper housing and the upper portion of the lower housing. A shear pin normally holds the sleeve in a fixed axial position with respect to the upper housing, thus maintaining the hammer in its remote position with respect to the primer.
The lower housing is provided with an external downwardly facing latching surface and a latching collet is disposed between the lower end of the outer sleeve and the outer periphery of the lower housing. The latching collet is provided with a plurality of spring arms having upwardly facing latching surfaces which are engagable with the downwardly facing latching surface provided on the lower housing. The latching collet is retained in its latching position, securing the upper and lower housings in axially abutting relationship by a collet support ring which is shearably secured to the outer sleeve.
In a normal operation of the firing mechanism, the application of a downwardly directed impact force to the wireline engagable member will effect a shearing of the shear screw holding the outer sleeve, and hence the hammer, in an elevated position relative to the primer. The hammer will move downwardly to impact the primer and detonate same. The detonation of the primer will effect the detonation of the downwardly directed shaped charge and this detonation will effect the fragmentation of both the closed bottom end of the upper housing and the closed top end of the lower housing, thus transferring the detonation to the booster charge and in turn to the primer cord extending to the perforating gun. If, for any reason, the primer or the downwardly directed spaced charge malfunction, the entire upper housing of the firing mechanism, including the primer and downwardly directed spaced charge element, may be removed from the remainder of the gun by attaching a wireline to a fishing neck provided on the top end of the wireline engagable member and applying an upwardly directed force thereto. Such force effects the shearing of the shear screws holding the collet support and permits the latching collet to move out of engagement with the downwardly facing latching surface on the lower housing, thus permitting the entire upper housing assembly to be removed from the well by wireline. Such removal is obviously rapidly accomplished and the defective elements of the firing mechanism contained in the upper housing may be replaced at the well surface. The repaired or a new upper housing is then lowered into the well by wireline and the upper housing is secured in axially abutting relationship to the top end of the lower housing by the latching collet, so that the entire firing mechanism is restored to an operative condition.
Further advantages of the invention will be readily apparent to those skilled in the art from the following detailed description, taken in conjunction with the annexed sheets of drawings on which is shown a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1B and 1C collectively represent a vertical quarter sectional view of a firing mechanism for a well perforating gun embodying this invention, with the elements of the gun shown in their run-in position, ready for firing.
FIGS. 2A, 2B and 2C are views similar to FIGS. 1A, 1B, and 1C, respectively, but showing the release of the collet latch from the lower housing preliminary to removing the upper housing from the well.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1A, 1B and 1C, a firing mechanism 1 embodying this invention may be secured to the top of any conventional tubing carried perforating gun (not shown) by a bottom connecting sub 2 having internal threads 2a for connection to the external threads conventionally provided on the top of the perforating gun. As is well known to those skilled in the art, such gun incorporates a plurality of vertically and angularly spaced shaped charges and the charges are detonated by a primer cord PC which extends downwardly into the gun into intimate contact with each of the detonating ends of each of the shaped charges (not shown). See for example Application Ser. No. 432,481, filed Oct. 4, 1982 (BSC-83) and assigned to the assignee of this application now patent No. 4,479,556.
The connecting sub 2 is provided with external threads 2b at its upper end for effecting a threaded connection to a length of tubing 3. O-rings 2c seal this threaded connection. The top end of tubing length 3 is provided with internal threads 3a which are connected to the bottom end of a top connecting sub 4. O-rings 4a seal this connection. The top sub 4 is provided with internal threads 4b for connection in conventional fashion to the bottom end of a tubing string 5.
The bottom sub 2 is further provided with internal threads 2e which threadably engage the bottom end of a hollow lower housing 10 which is formed by the threaded assemblage of two tubular members 10a and 10b. O-rings 2d seal the threaded connection of the lower housing 10 to the bottom sub 2 and threads 10c and O-ring 10d effect the sealed connection of the two tubular members forming the lower housing 10. Those skilled in the art will recognize that the lower housing 10 may be formed as an integral member, but the two piece construction is preferred so as to permit a variety of lengths of this housing to be selected, depending upon the amount of trash which is anticipated may collect around the housing prior to the firing of the perforating gun.
The upper end of housing element 10b is provided with a solid, relative thin end wall 10e. Within the bore 10f of the lower housing 10, a conventional booster charge 6 is mounted which is connected to the upper end of a primer cord PC which extends downwardly into the perforating gun (not shown). Lastly, the upper housing element 10b is provided with an annular recess 10g on its periphery defining a downwardly facing latching surface 10h, for a purpose to be hereinafter described.
From the description thus far, it will be apparent that the booster charge 6 and the primer cord PC are housed within the sealed interior of the lower housing 10 and thus are protected from contact with any corrosive or otherwise deleterious fluids or gasses existing in the well in the vicinity of the perforating gun. Thus, the housing 10, together with the booster charge 6 and primer cord PC, may be run into the well on the tubing string at the same time that the perforating gun (not shown) is run-in, and may remain in the well for an extended period of time without any adverse effects on the booster charge and primer cord. The tubing carried perforating gun normally employed has a completely sealed bore within which the shaped charges are mounted and these charges are likewise not effected by the well environment. See for example the aforementioned co-pending application.
The second half of the firing mechanism comprises an upper housing 20 which has a relatively thin bottom end wall 20a which is normally disposed in abutting relationship to the solid top wall 10e of the lower housing 10. Upper housing 20 defines an upwardly extending bore 20b which has a first counter bore defining an upwardly facing surface 20c upon which is mounted a nylon support ring 21 for conventional shaped charge 25 which is positioned on the support ring 21 so as to direct its explosive force downwardly. The explosive force of the downwardly directed shaped charge 25 is sufficiently great so as to blast through and fragmentize both the bottom end wall 20a on the upper housing 20 and the top end wall 10e of the lower housing 10.
A second counter bore is formed in the bore 20b of upper housing 20 to define an upwardly facing shoulder 20d. This shoulder mounts a spacer ring 22 having an inclined lower surface 22a engaging the conventional rounded upper surface of the downwardly directed shaped charge 25. The upper surface 22b of spacer ring 22 lies in a radial plane and effects an abutting engagement with the bottom end of a detonatable primer 28. An O-ring seal 28a seals this connection, while an O-ring seal 22c effects the sealing of the periphery of the spacer ring 22 with the counter bore 20e of the upper housing 20.
The primer 28 is held in a fixed position in the upper housing 20 by a hammer support sleeve 24 which is threadably secured to internal threads 20f provided at the top end of the upper housing 20. An O-ring 24a seals this connection while an O-ring 24b sealingly engages the top surface of the primer 28.
A hammer 30 having a pointed lower end 30a is mounted for sliding movements within the bore 24c of the hammer support sleeve 24. The upper end of hammer 30 is provided with external threads 30b for securement to internal threads provided on a wireline attachable member 35 having a fishing neck 35a formed on its upper extremity. Thus the position of the pointed end 30a of the hammer 30 relative to the primer 28 is determined by the relative position of the wireline engagable element 35 with respect to the upper housing 20.
This position is determined by an outer sleeve 40 which is secured at its upper end to external threads 35b provided on the lower end of the wireline engagable element 35. A shear screw 41 traverses the wall of outer sleeve 40 and engages an annular slot 20h formed in the lower portions of the upper housing 20. This shear screw thus determines the relative position of the wireline engagable element 35, hence the hammer 30 with respect to the primer 28.
The lower end of outer sleeve 40 surrounds the upper end of the lower housing 10 and is provided with external threads 40c. A collet mounting sleeve 45 is secured to threads 40c and extends downwardly in radially spaced relationship to the outer surface of the lower housing 10, terminating in a radially inward projecting portion 45a which abuts the external surface of lower housing 10. The annular space 46 defined between the collet mounting sleeve 45 and the exterior surface of lower housing 10 is employed for mounting a latching collet 50 having a ring portion 50a and a plurality of peripherally spaced downwardly extending resilient arm portions 50b. The arm portions 50b terminate at their lower ends in a radially enlarged portion 50c defining an upwardly facing latching surface 50d. Whenever a minor upward force is applied to the wireline engagable element 35 or the outer sleeve 40, a collet locking ring 48 will move into abutting engagement with the enlarged end portions 50c of the collet arms 50b and prevent the release of such arms from the downwardly facing latching surface 10h provided on the lower housing 10. However, when a sufficiently large upward force is applied to the wirline engagable element 35, the shear screws 49 will be severed and the collet locking ring 48 will be shifted downwardly relative to the collet mounting sleeve 45 to permit the collet arms 50b to be cammed outwardly into the longitudinally extending windows 45d provided in the body of the collet mounting sleeve 45, thus releasing upper housing 20 from lower housing 10, as illustrated in FIG. 2B.
The operation of the apparatus embodying this invention will be readily apparent to those skilled in the art. As previously mentioned, the lower housing 10, with its contents, are run into the well with the perforating gun. The upper housing 20 may be latched to the lower housing 10 by the latching collet 50 and concurrently run into the well. Alternatively, the upper housing 20, together with the latching collet 50, outer sleeve 40 and wireline engagable member 35 may be subsequently lowered by wireline into the well and latchingly engaged in the position illustrated in FIGS. 1A, 1B and 1C to the lower housing 10 by the latching collet 50.
The firing mechanism is actuated either by dropping a detonating bar 18 into impact engagement with the upper end of the wireline engagable element 35 or by imparting a similar downward impact force to such member by jars incorporated in a wireline connected to member 35. In either event, such downward impact force will effect the shearing of shear element 41 and will thus release the wireline engagable member 35 from the upper housing 20 and permit such member, together with the hammer 30, to move downwardly into impact engagement with the primer 28. The detonation of the primer 28 will effect the firing of the downwardly directed shaped charge 25. This explosive charge will fragmentize the solid end wall 20a of the upper housing 20 and the solid end wall 10e of the lower housing 10, thus resulting in the detonation of the booster charge 6. The detonation of the booster charge 6 will effect the detonation of the primer cord PC which, in turn, will effect the discharge of all the shaped charges contained in the perforating gun. In some cases, the booster charge 6 may be eliminated and the primer cord PC can be directly detonated by the shaped charge 25. Thus said primer cord, with or without the booster charge 6 constitutes a detonatable firing element for the perforating gun.
If for any reason the primer 28 does not detonate, or the downwardly directed explosive charge 25 is not discharged, the entire upper housing 20 containing these defective elements may be removed from the well by engaging the fishing neck 35a of the member 35 with a wireline operated fishing head. Upward force applied to the member 35 will effect the shearing of shear screws 49 and the release of the latching collet 50 from latching engagement with the lower housing 10, permitting all of the upper housing 20, the outer sleeve 40, the collet mounting sleeve 45 and the latching collet 50 to be removed from the well, as shown in FIGS. 2A and 2B. Upon replacement or repair of the defective firing elements of this assemblage, the entire upper housing assemblage can then again be reinserted in the well by wireline and secured in the position illustrated in FIGS. 1A, 1B, and 1C through the engagement of the latching collet 50 with the lower housing 10. During the downward passage of the upper housing assemblage into the well, it should be noted that any obstructions encountered by the depending collet mounting sleeve 45 will not result in the production of any force tending to move the hammer 30 toward engagement with the primer 28.
It is therefore apparent that the aforedescribed invention provides the well operator with an unusual degree of flexibility in that he can select the time for arming the downhole portion of the firing mechanism by wireline, and in the event of a failure of the firing mechanism to function, he may conveniently remove the defective portion of the firing mechanism for repair and replacement without necessitating the pulling of the entire tubing string upon which the perforating gun is suspended.
Although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention. | A firing mechanism for a downhole perforating gun comprises two cooperating housing sections having closed end walls in abutment. The lower housing section contains a booster charge and the primer cord for firing the gun. The upper housing section contains a detonatable primer, a hammer, and a downwardly directed explosive charge positioned between the primer and the bottom end wall of the upper housing. The upper housing is secured to the lower housing by a collet latch which, if firing of the gun does not occur, can be released by the exertion of a substantial upward force on a fishing neck provided in the assemblage of the upper housing. The defective elements can then be repaired or replaced, the upper housing reinserted in the well by wireline, and latched into an operative position with respect to the lower housing to permit another attempt to fire the perforating gun. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation application of and claims the benefit of priority under 35 U.S.C. §120 of U.S. application Ser. No. 13/278,980, filed Oct. 21, 2011, and claims the benefit of priority under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/405,975, filed Oct. 22, 2010, and the entire contents of each of the above are incorporated herein by reference.
BACKGROUND
1. Field
The embodiments discussed herein relate to a panel mounting system. More specifically, a system of extrusions for attaching panels to a building is described.
2. Description of the Related Art
Generally, a mounting system for mounting metal skin exterior panels on structural members of a building must have four basic characteristics: (1) load carrying capability to support the panels without substantial deformation; (2) adjustability to facilitate attachment of the panels to the structural members; (3) tight sealing to minimize infiltration of wind, rain, snow, hail and the like; and (4) removability to allow removal of any panel and/or seal member without disturbing others. However, it is known that the wall panels are widely used to create a finished, durable, and aesthetic appearance on building walls of all types, as well as for panels for truck bodies, shipping containers, and the like. The panels are typically formed as laminates of outer surface sheets bonded to inner core layer or layers that have structural strength and rigidity, yet are light-weight, flexible under building and environmental stresses, and attractive for the external or interior appearance of building walls.
The panels are mounted to building walls by various types of mounting devices. For example, one-piece channel-shaped extrusions of metal or rigid plastic are widely used to retain the panels at joints and corners. With conventional extrusion designs, installation proceeds progressively by first installing a corner or terminal extrusion, then a panel, then an “H” (straight, two-sided) extrusion, then another panel, and so on until another corner of termination is reached. Installers must be able to size the panels, position the mounting extrusions, and form joints that are properly aligned and cleanly formed.
However, conventional mounting systems using extruded devices have been rather inconvenient to use and expensive. With one-piece extrusions, installation proceeds in one direction along a building wall, and caulking the gaps between the panel edges and the extrusions must be done at the time of installation. If the panels are misaligned or a panel becomes damaged, the panels must be removed in sequence in the backward direction. An individual panel cannot be removed out of sequence. The already-installed caulking must be removed or it will detract from the clean appearance of the panels. With one-piece extrusions, the panel fitting and caulking must be done correctly when first installed. Installers may be tempted to leave out the caulking to facilitate panel repair or removal, but this can lead to panel and building failure due to water seepage through the gaps and into the building walls.
Additionally, extrusions in conventional mounting systems typically include a flange or extension that surrounds or overlaps the outer perimeter of the panel to retain and secure the panel to the building or other body to which the panel is mounted. For example, the outer perimeter of the panels may be inserted into a slot or groove of the extrusion so that one wall of the slot or groove is visible on the exterior of the mounted panel. The walls of the slot may be somewhat flexible and are typically spaced for the thickness of the panel. Another conventional mounting system includes multiple components, where the back of the panel is placed against a first component attached to the wall and then a second component snaps into the first component at a joint between adjacent panels. However, this second component includes an extension that overlaps the outer perimeter of the panel, such that a portion of the mounting system is again visible at the exterior edges of each panel section.
Thus, conventional mounting systems such as those described above do not provide a clean, planar surface for the exterior faces of the mounted panels because the flange or the extension securing the edge of the panels is raised from the panel edge and may be of a noticeably different color.
Furthermore, due to the variety of sill flashings, head flashings, and parapet flashings, which are often provided by the various door and window manufacturers, conventional mounting systems are not always compatible with the various flashings and can be troublesome for installers arriving at the jobsite with no directions on how to handle the intersection of two different building materials.
SUMMARY
One exemplary embodiment of the present invention provides a mounting apparatus for mounting a panel to a structure. The mounting apparatus includes one or more panel extrusions that attaches to a back side of the panel such that the panel extrusions are obscured behind the panel. A connector extrusion secures the panel extrusions to the structure.
Another exemplary embodiment of the present invention provides a mounting system for mounting panels to a structure. The mounting system includes an air and water barrier layer, a strip of foam tape disposed on the air and water barrier layer, and a panel assembly. The panel assembly includes a panel and one or more panel extrusions attached to a back side of the panel such that the panel extrusions are obscured behind the panel. A connector extrusion secures the panel assembly to the structure. The connector extrusion is disposed on the strip of foam tape to achieve leveling and seals.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings. However, the accompanying drawings and their exemplary depictions do not in any way limit the scope of the inventions embraced by this specification. The scope of the inventions embraced by the specification and drawings are defined by the words of the accompanying claims.
FIG. 1 is an external perspective view of an installed mounting system according to an exemplary embodiment of the invention;
FIG. 2 is a perspective view of the back side of a panel assembly according to an exemplary embodiment of the invention;
FIG. 3 is a perspective view of a cross-section of the mounting system according to an exemplary embodiment of the invention;
FIG. 4 is a perspective view of a panel extrusion according to an exemplary embodiment of the invention;
FIG. 5 a is a perspective view of a connector extrusion according to an exemplary embodiment of the invention;
FIG. 5 b is a perspective view of an end-of-run connector extrusion according to exemplary embodiment of the invention;
FIG. 6 is a cross-sectional view of two adjacent panel assemblies mounted to a structure according to an exemplary embodiment of the invention;
FIG. 7 is a cross-sectional view of an end run of a panel assembly mounted to a structure according to an exemplary embodiment of the invention;
FIG. 8 is a cross-sectional view of a v-groove cut in a panel according to an exemplary embodiment of the invention;
FIG. 9 is a perspective view of a spring clip according to an exemplary embodiment of the invention;
FIG. 10 is a perspective view of a spring clip inserted in a panel according to an exemplary embodiment of the invention;
FIG. 11 is another perspective view of a spring clip inserted in a panel according to an exemplary embodiment of the invention;
FIG. 12 is a perspective view of an insert strip with a spring clip in each side according to an exemplary embodiment of the invention;
FIG. 13 is perspective view of an insert strip with multiple spring clips in each side of the insert strip according to an exemplary embodiment of the invention; and
FIG. 14 is a perspective end view of an insert strip showing the ends of spring clips extending into the panel extrusions according to an exemplary embodiment of the invention.
DETAILED DESCRIPTION
In the following, the present advancement will be discussed by describing a preferred embodiment with reference to the accompanying drawings. However, those skilled in the art will realize other applications and modifications within the scope of the disclosure as defined in the enclosed claims.
FIG. 1 is a perspective view of a finished wall 10 with panels 12 mounted using the mounting system described herein. The panels 12 are typically mounted using only three specialized extrusions (not all shown in FIG. 1 ). The panels 12 and insert strips 14 obscure the extrusions so there is a clean look to the finished wall 10 . In one non-limiting embodiment, it is preferable to use a panel having a corrugated core laminated between two metallic sheets (see FIG. 8 ). When properly installed, the mounting system provides at least five seals that trap and drain water to the outside of the structure. The five seals are discussed in detail below.
FIG. 2 depicts a completed panel assembly 20 from the back side. A panel assembly includes the panel 12 and panel extrusions 30 . The panel extrusions 30 are visible from the back side of the panel assembly 20 , however, after installation, the panel 12 obscures the panel extrusions 30 , as discussed above. Once a panel assembly 20 is installed by securing it to a structure, insert strips 14 are placed adjacent to panel edges to obscure the connector extrusions 40 (see FIG. 3 ).
FIG. 3 shows a perspective view of the junction between adjacent panel assemblies 20 . For clarity and to avoid obscuring the lines on the figure, the connector extrusion 40 is shown raised in the gutter space between the panel extrusions 30 . When installed, however, the connector extrusion 40 secures the panel extrusions 30 to the structure. As mentioned above, the insert strip 14 is disposed between the two panel extrusions 30 to hide the connector extrusion 40 .
A perspective view of a panel extrusion 30 is shown in FIG. 4 . The following description of the features of the panel extrusion 30 is discussed in relation to the disposition of the panel extrusion as shown in FIGS. 6 and 7 . The panel extrusion 30 is typically formed as a single extruded piece and then cut according to the required lengths. The panel extrusion 30 includes: an intermediate portion 33 , extensions 34 , a panel-side flange 31 , a structure-side flange 32 , and an insert strip flange 36 .
When the panel extrusion 30 is installed, the panel-side flange 31 is secured to the panel 12 in the panel assembly 20 , and the structure-side flange 32 is secured to the wall 100 of the structure. Although one of ordinary skill in the art will recognize that other shapes and positions may be used for the flanges 31 and 32 , in the non-limiting embodiment shown in FIGS. 4, 6, and 7 , the flanges 31 and 32 are substantially flat and extend from respective extensions 34 in opposite directions. It is preferred that the structure-side flange 32 extends in a direction outward from the panel 12 so as to engage with the connector extrusion 40 and to be secured to the wall 100 . The extensions 34 extend from opposite ends of the intermediate portion 33 in opposite directions, thereby adjoining the flanges 31 and 32 to the intermediate portion 33 .
The panel extrusion 30 also includes an insert strip holding portion 35 . In one non-limiting embodiment, the insert strip holding portion 35 is a slot having an opening that is approximately the same width or smaller than the thickness of an insert strip 14 . The slot of the insert strip holding portion 35 is delimited by the insert support flange 36 , the extension 34 , and the intermediate portion 33 . In particular, the insert support flange 36 extends from the extension 34 adjacent to the intermediate portion 33 in a direction such that, when the panel extrusion 30 is installed, the insert strip holding portion 35 opens outward so as to receive an insert strip 14 .
As seen in FIGS. 6 and 7 , the majority of the insert support flange 36 is substantially parallel to the intermediate portion 33 , however, it is understood that one of ordinary skill in the art could alter the position and/or shape of the insert support flange 36 to another angle, so long as the opening of the slot remains substantially the same width or smaller than the thickness of the insert strip 14 . Further, an end portion 37 of the insert support flange 36 may be angled so that it is not co-planar with the majority of the insert support flange 36 . Additionally, it is preferable that the end portion 37 of the insert support flange 36 is angled in a direction away from the intermediate portion 33 , which may ease insertion of the insert strip 14 into the insert strip holding portion 35 .
Furthermore, the panel extrusion 30 includes a raised ridge 38 that runs the length of the intermediate portion. Depending on the width of the insert strip 14 , the ridge 38 may assist in securing the insert strip 14 to the panel extrusion 30 , as shown in FIG. 7 .
The following description of the features of the connector extrusion 40 is discussed in relation to the position of the connector extrusion as shown in FIGS. 6 and 7 . There are two versions of the connector extrusion 40 , a connector extrusion 40 having two projection legs 44 , as seen in FIGS. 5 a and 6 , and a connector extrusion 40 having a single projection leg 44 (an end-of-run connector), as seen in FIGS. 5 b and 7 . The two versions, however, are otherwise substantially the same and therefore, the reference numerals used are the same for both versions.
Like the panel extrusion 30 , the connector extrusion 40 is also typically formed as single extruded piece and then cut according to the required lengths. The connector extrusion 40 includes: a groove 42 and at least one projection leg 44 .
The groove 42 of the connector extrusion 40 is delimited by side walls 42 a and a junction wall 42 b that adjoins the two side walls 42 a . In a non-limiting embodiment, it is preferred that a lower portion of each of the two side walls 42 a extends past the junction wall 42 b . In the version of the connector extrusion 40 with only one projection leg 44 , the projection leg 44 extends from one of the two side walls 42 a away from the groove 42 . In the version of the connector extrusion 40 with a projection leg 44 extending from each side wall 42 a , the two projection legs 44 extend in opposite directions away from the groove 42 . Preferably, in a non-limiting embodiment, the projection legs 44 are substantially perpendicular to the side walls 42 a from which the projection legs 44 extend.
As shown in FIGS. 6 and 7 , panel assemblies are mounted to a structure by engaging the structure-side flange 32 of the panel extrusion 30 with the projection leg(s) 44 of the connector extrusion 40 . FIG. 6 shows a cross-sectional view of the junction between two adjacent mounted panel assemblies 20 . As mentioned above, a panel assembly 20 includes the panel 12 that is connected to a panel extrusion 30 . Typically, the panel 12 is prepared from a planar panel that has been cut with a v-groove 50 (see FIG. 8 ) near each side edge and folded at the cut to make a return edge 12 a and form a box shape. The preferred method of cutting the v-groove is described below. The return edge 12 a of the panel 12 is typically 1 ″ in width, but may be wider or narrower depending on the needs of the particular job. The panel extrusions 30 are correspondingly sized and cut and are typically attached to the inside corners of the box-shaped panel 12 . Preferably, a fastener 24 , such as a screw for example, is used to fasten the panel 12 to the panel extrusion 30 . Additionally, a sealant 22 may be disposed between the panel extrusion 30 and the inside surface of the panel 12 . The sealant 22 is preferably a silicone sealant.
In another non-limiting embodiment, the mounting system further includes: an air and water barrier layer 102 , and a strip of foam tape 104 . The order of the assembled components is as follows. The air and water barrier layer is typically adhered to the surface of the wall 100 and then the strip of foam tape 104 is adhered to the surface of the air and water barrier layer 102 . The connector extrusion 40 is secured to the strip of foam tape 102 with a fastener 26 and engages the structure-side flange 32 , securing the structure-side flange 32 to the strip of foam tape 102 as well. Thus, the panel assemblies 20 are secured to the wall 100 .
The assembly shown in FIG. 7 is substantially the same as described with respect to FIG. 6 , however, as mentioned previously, FIG. 7 depicts a single panel extrusion 30 and a connector extrusion 40 with only one projection leg 44 . In addition, the panel insert 14 is secured only on one side by the insert strip holding portion 35 .
As mentioned above, the complete installed mounting system 10 provides five seals that trap and drain water to the outside of the structure. The five seals are described below with reference to FIG. 6 . The first seal is formed at the contact points of the outer surface of the insert strip 14 with the intermediate portion 33 of the panel extrusion 30 . The second seal is formed at the contact points of the inner surface of the insert strip 14 with the insert support flange 36 over the gutter space, which is between the insert strip 14 and the connector extrusion 40 . The third seal is formed at the contact point between the projection leg 44 of the connector extrusion 40 and the structure side flange 32 of the panel extrusion 30 . The fourth seal is formed between the strip of foam tape 104 and the structure side flange 32 . The fifth seal is formed between the strip of foam tape 104 and the air and water barrier layer 102 . Accordingly, when all of the above components are properly installed, the mounting system has five seals to prevent water from entering the structure to which the panels are mounted.
FIG. 8 is a cross-sectional view of a v-groove 50 cut in a panel 12 to form the box shape. The v-groove 50 may be formed by any of a variety of ways known to those skilled in the art. In a non-limiting embodiment using a laminated panel 12 , it is preferable that the v-groove 50 pass through one of the outer metallic sheets, all the way through the corrugated core, and then begin to cut away a small amount of the inner surface of the opposing metallic sheet. It is preferred to cut the v-groove 50 in the above-described manner so that the panel 12 bends easier and straighter, and does not leave a mark on and/or penetrate the outer surface of the opposing metallic sheet, which would ruin the panel 12 .
A spring clip 60 is depicted in FIG. 9 . The spring clip 60 is used to hold in place narrow insert strips, which would otherwise rest so that the insert strip does not entirely cover the intermediate space between adjacent installed panel assemblies 20 . The spring clip 60 is typically formed as a cylindrical thin rod and then bent to the desired shape, discussed herein. Preferably, the spring clip is an elastic metal, however, other elastic materials may be suitable. In one non-limiting embodiment shown in FIGS. 9-13 , the spring clip 60 includes: an arm extension 61 , a first bend 62 , a first extension 63 , a second bend 64 , a second extension 65 , a third bend 66 , an third extension 67 , and a fourth bend 68 .
The arm extension 61 of the spring clip 60 extends away from the first extension 63 such that the first bend 62 is an angle between approximately 90 and 150 degrees, and preferably approximately 120 degrees. The second bend 64 connects the second extension 65 and the first extension 63 . The second bend 64 forms a loop which allows the first extension 63 and the second extension 65 to be substantially parallel, however the second extension 65 extends from the second bend 64 in a plane that is distinct from the plane along which the first extension 63 extends. The third bend 66 forms a loop which allows the second extension 65 and the third extension 67 to be substantially parallel. Additionally, the third extension 67 may extend from the second bend 64 in substantially the same plane along which the second member 63 extends. The fourth bend 68 , located at the end of the arm extension 61 , prevents the spring clip from digging into the panel once the insert strip is installed.
FIGS. 10 and 11 show the spring clip 60 inserted into the side of an insert strip in two different positions, such that in the position shown in FIG. 10 , the arm extension 61 extends in a first angled direction and in the position shown in FIG. 11 , the arm extension 61 extends in a second angled direction. Further, in FIG. 10 , the third extension 67 remains against the exterior surface of the insert strip such that only the first and second extensions 63 and 65 are inserted into the core of the insert strip. In FIG. 11 , however, the third extension 67 is inserted into the core of the insert strip beside the first and second extensions 63 and 65 . FIG. 12 further illustrates the positions shown in FIGS. 10 and 11 , as the spring clips 60 a and 60 b are inserted into opposite sides of the same insert strip 14 . Once inserted into the insert strip 14 , the arm extensions 61 typically extend at approximately a 45° angle with respect to the edge of the insert strip 14 where the spring clips 60 a and 60 b are inserted.
The two different positions of insertion of the spring clips 60 a and 60 b , as shown in FIG. 12 , cause the arm extensions 61 to hold specific positions with respect to the insert strip 14 . Specifically, the arm extension 61 of spring clip 60 a lies in the plane of the panel surface of the insert strip 14 , at a position of 45° from the cut longitudinal edge of the insert strip 14 . The arm extension 61 of spring clip 60 b is positioned 45° away from the plane of the panel surface of the insert strip 14 , and 45° away from the plane of the cut longitudinal edge of the insert strip 14 , which is perpendicular to the plane of the panel surface of the insert strip 14 .
FIG. 13 shows an insert strip in position to be inserted between panel assemblies 20 . The insert strip in FIG. 13 includes two spring clips 60 on each side.
As depicted in the cross-sectional view in FIG. 14 , the insert strip 14 is inserted into the junction area between two panel assemblies 20 . The arm extensions 61 of the spring clips 60 extend from the sides of the insert strip 14 and abut the panel extrusion 30 to place the insert strip between the two panel assemblies 20 , thereby concealing the mounted connector extrusion 40 .
Obviously, 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. | A mounting apparatus for mounting a panel to a structure. The mounting apparatus includes a panel extrusion that attaches to a back side of the panel such that the panel extrusion is obscured behind the panel in order to show a clean surface look. A connector extrusion secures the panel extrusion to the structure for simple construction. | 4 |
BACKGROUND OF THE INVENTION
1. Field or the Invention
The present invention pertains to instruments to depth measurement or loosely laid pavement mixtures and more particularly to depth measurement instruments used to measure a hot bituminous pavement layer while paving before compaction to determine whether the proper depth or pavement has been set in place.
2. Related Prior Art
Presently, measuring the mat thickness of a bituminous paving layer before compaction is normally done by a very simple portable device. This device usually consists of a one quarter inch rod that has an adjustable washer. The rod with washer fixed in place is inserted into the recently laid bituminous pavement mixture of aggregates and asphalt cement. The rod may be several feet long so that it is easy to handle and can measure significant depths of pavement. The rod may also be threaded so that a lock nut can be used in conjunction with the washer. The washer may be fixed to the nut so that it will not slide when the nut is screwed in place. In most instances, the washer is used in conjunction with a set screw. This arrangement avoids the problem of asphalt tar filling in the threads and preventing movement to the nut.
A ruler normally is used to measure the distance from the end of the rod to the washer to set the desired mat thickness. The washer is then locked down on the rod usually by means of a set screw. The person measuring the mat or bituminous paving layer thickness then walks where the mat has just been laid and shoves the rod into the bituminous paving layer. The rod is pushed into the bituminous paving to see if the rod goes to or exceeds the distance of the washer from the end of the rod. If the washer does not touch the mat, the thickness of the mat is increased. If the bituminous paving exceeds the depth of the washer, the thickness is decreased.
One problem associated with such a device comes from the composition of the paving material itself. This problem occurs primarily because of the size of some of the aggregates used to make certain types of bituminous paving. In some types of bituminous paving the larger aggregates may be one and one half inches in diameter and larger in size. The washer generally is two inches in diameter. If the rod is pushed into the bituminous paving when the mat depth exceeds the desired depth, the washer may be held up by one of these large aggregates before the rod reaches the bottom of the paving layer. This can lead to an inaccurate reading witch results in a false measurement of the thickness of the mat.
When the washer hits a large aggregate and fails to reach the bottom of the pavement layer and an inaccurate measurement is taken. In one situation, the spreader operator may mistakenly believe the depth to be proper and continues to lay down a mat too thick. Or, possibly in another situation, the operator may receive an indication of the depth being too thick. However, since the washer was held up by a large aggregate, the operator would correct for a paving layer having a thickness of too great of a depth by the measured amount. Unfortunately, a correction was made but not great enough because the depth gauge did not measure the true depth. This would result in the amount of reduction to be too small and result in a loss because of the error in the measurement obtained by the rod and washer device. In both of these cases, too much bituminous is being laid and costs can increase by as much as twenty percent.
SUMMARY OF THE INVENTION
The method and apparatus of the present invention eliminates the problem of faulty depth measurement encountered by prior art depth measurement gauges. The bituminous paving depth gauge of the present invention eliminates the need of the fixably attached washer that in some cases can prevent the rod from going down to the complete depth of the mat.
The method of the present invention for measuring the paving layer depth in a bituminous paving operation includes inserting a rod member into the pavement layer, aligning an indicator on the rod with a graduated measuring section on a support member and reading the depth. The rod member has an indicator at its top and a gradually narrowing end for insertion into the paving layer. The gradually narrowing end is designed so that the rod member can easily be inserted into the uncompacted bituminous paving mixture by pushing the aggregates out of the way, allowing the tip of the rod to touch the prepared surface for receiving the pavement. The rod member is supported by a support device having a top portion and a bottom portion. The top portion includes a measuring section having predetermined graduations. This measuring section acts in cooperation with the indicator to provide a measurement of the pavement layer or mat. The bottom portion has support sections for receiving and sildeably holding the rod member. Reading a depth measurement is done according to the position of the indicator with respect to the measuring section. The method for measuring the paving layer depth in a bituminous paving operation may also include preventing the support device from sinking into the paving with a base member mounted on the bottom portion of the support device.
The apparatus of the present invention provides a top reading bituminous paving depth gauge to determine the thickness of paving layers. The gauge of the present invention includes a depressible rod operatively associated with a structural rod support system. The depressible rod has a bottom portion that is slideably mounted in the rod support system. The rod support system has an upper portion and a lower portion. The upper portion includes a graduated measuring gauge fixed on the rod support system. The lower portion has a bottom support device fixed to the lower end of the rod support system. The bottom support device acts as a foot for the measuring gauge. This foot rests on the bituminous paving when the measuring gauge is set in place to measure the depth of the mat. The bottom support device also acts to receive the lower portion of the depressible rod. The top reading bituminous paving depth gauge operates without any washers on the measuring depressible rod to prevent false measurements due to the presence of large aggregates. The upper portion with its graduated measuring gauge fixed on the rod support system operates in conjunction with an indicator on the top of the depressible rod to provide a mark for accurately measuring the depth of the bituminous paving. The indicator is at zero on the measuring gauge when the bottom of the depressible rod is flush with the foot of the bottom support device.
The rod portion of the present invention has no washer that would prevent the rod from going the complete depth of the mat. The rod is preterably five feet long and has a cone shaped bottom to allow insertion into the bituminous paving layer or mat. With the narrowed tip of the cone shaped bottom at the end of the rod, the rod is pushed into the bituminous paving with little effort by the operator of the bituminous layer measuring device. The measuring of the thickness is done from the top of the device of the present invention. When the rod enters the paving the top of the rod lines up with the gauge which is in one quarter inch increments giving an accurate measurement of the mat thickness. The foot on the bottom of the rod support portion of the device of the present invention is preferably three inches by three inches and keeps from sinking into the bituminous paving. The total length of the bituminous paving depth gauge of the present invention is approximately five feet. In this manner the measuring portion of the apparatus of the present invention is places at eye level for easy reading of the depth of the mat. The bituminous paving depth gauge of the present invention is preferably made from aluminum so that is light weight and portable. Thus, it may be carried in a vehicle or in a case mounted on the spreader which would give personnel easy access to the device of the present invention for measuring the bituminous paving layer thickness or depth.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the bituminous paving layer depth gauge of the present invention.
FIG. 2 is an isometric view of the bituminous paving layer depth gauge of FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
The apparatus of the present invention eliminates the problem of faulty depth measurement encountered by prior art depth measurement gauges by removing the need of the fixably attached washer of prior art devices. The present invention provides a top reading bituminous paving depth gauge for measuring the thickness of paving layers. This gauge has a depressible rod operatively associated with a support system. The depressible rod may have a bottom portion with a pointed tip that fits in the rod support system and may have an indicator positioned at some point on the rod. The rod support system has a portion including a graduated measuring section fixed on the rod support system and a portion including a bottom support device fixed to its lower end. The graduated measuring section may be in any location of the support system to act in cooperation with the indicator and its position on the depressible rod.
The depressible rod portion of the present invention has no washer that would prevent the rod from going the complete depth of the mat. The rod is preferably five feet long and has a cone shaped bottom to allow insertion into the bituminous paving layer or mat. With the narrowed tip of the cone shaped bottom at the end of the rod, the rod is pushed into the bituminous paving with little effort by the operator of the measuring device.
Referring now to FIG. 1, a side view of a bituminous paving depth gauge 10 of the present invention is illustrated as having a support system 12 and a depressible rod 14 . The movably mounted depressible rod 14 is shown with an indicator 16 at its top end 18 and a handle 20 located closer to the middle or rod 14 . Although handle 20 is designed for ease of movement in inserting rod 14 into the paving mat, handle 20 is located towards the middle of rod 14 for balance so that paving depth gauge 10 may be carried by handle 20 when moved from one measuring location to the next. Lower end 22 or rod 14 is illustrated as narrowing to a rounded point 24 .
Depressible rod 14 is preferably made or a {fraction (3/16)}″ steel rod for providing the maximum amount of strength while adding the minimum amount of size and weight to paving depth gauge 10 . However, it is to be noted that any material may be used as long as it is strong and heat resistant so that it may be inserted repeatedly into the hot bituminous paving mixture, a mixture of asphalt cement and hot aggregates, without any deleterious ettects. In addition, the material for the depressible rod has a secondary requirement, that is, it must be able to be shaped or reduced in size to narrowed rounded point 24 without compromising its strength. The strength and heat resistance or the material refer to the ablilty of depressible rod 14 to be able to move loosely piled aggregates out of the way as it is pushed to the earth surface where the bituminous paving layer begins. In this respect, the material from which depressible rod 14 is made must retain its rigidness despite the heat of the bituminous paving mixture.
Depressible rod 14 has handle 20 located close to its middle. Handle 20 is positioned for balance to facilitate the moveability of depressible rod 14 . Positioning handle 20 in this manner allows depressible rod 14 to slide from its zero position to its maximum depth reading. Handle 20 may also serve as the carrying device for transporting paving depth gauge 10 between measurement locations. In this regard, handle 20 is preferably four inches long to allow a person to grip handle 20 comfortably. In this regard, handle 20 may be knurled to fit finger spaces to provide a comfortable grip. Handle 20 is preferably welded onto rod 14 and may be made of a steel rod of the same diameter as rod 14 . Thus, the added strength permits the entire depth measuring gauge 10 to be lifted by handle 20 . support system 12 includes a top portion 26 and a bottom portion 28 . Top portion 26 of support system 12 includes a graduated section 30 having graduated marks, ranging from zero to a predetermined number. The graduated marks of measuring section 30 are used in conjunction with indicator 16 to provide an easily readable gauge for viewing the depth of the bituminous pavement. In the preferred embodiment, twelve inches of graduated marks are preferred. The graduated marks are preferably every one quarter of an inch although any spacing may be used to provide a graduated measurement of the depth of the bituminous paving. Zero for graduated section 30 preferably occurs at the very top of top portion 26 of support system 12 in the preferred embodiment. This location was chosen so that the portion where the depth of the mat is read would be approximately eye level and the depth could easily be called out to the operator. The zero mark on graduated section 30 is the position of indicator 16 of depressible rod 14 when the tip of rounded point 24 at lower end 22 of depressible rod 14 is flush with the bottom support system 12 when it is resting on the top of the bituminous paving layer. The zero mark for graduated section 30 may be at any position on support system 12 as long as it is coordinated with the position of indicator 16 of rod 14 .
Support system 12 includes brackets 32 A, 32 B and 32 C. The spacing between brackets 32 A, 32 B and 32 C may be sized to provide balance in the instrument, however, the spacing between brackets 32 A and 32 B must be adequate to permit handle 20 to travel sufficient distance for indicator 16 to traverse all the graduated marks or graduated measuring section 30 . Brackets 32 A, 32 B and 32 C include holes 34 A, 34 B and 34 C, respectively, drilled in each bracket to permit travel of rod 14 to the bottom of the bituminous paving mat.
At a midpoint of support system 12 , a carrying handle or cutout (not shown) may be provided so that measuring gauge 10 may be carried.
Bottom portion 28 includes a bottom support device or base 36 fixed to its lower end 38 . Bottom support device or base 36 provides a stop for measuring gauge 10 to provide an area upon which it may rest. Base 36 also acts to receive lower portion 22 of depressible rod 14 . Base 36 rests on the bituminous paving when bituminous paving layer depth gauge 10 is set in place for measuring. Upper portion 26 with its graduated measuring section 30 fixed on top portion 26 rod support system 12 operates in conjunction with indicator 16 on top end 18 of depressible rod 14 to provide a mark for accurately measuring the depth of the bituminous paving. The indicator is at zero on measuring portion 30 when rounded point 24 of depressible rod 14 is flush with the bottom or base 36 of support system 12 . The reading or the thickness measurement is done from top portion 26 of the device of the present invention. When rod 14 enters the paving, the top or indicator 16 of rod 14 lines up with graduated portion 30 . As rod 14 is inserted into the pavement mat, the indicator is aligned with the graduated marks of section 30 . With the alignment being done at eye level, an accurate measurement of the mat thickness is readily obtained. The foot on the bottom of the rod support portion of the device of the present invention, base 36 , is preferably three inches by three inches. This size keeps the bituminous paving depth gauge 10 of the present invention from sinking into the bituminous paving.
The total length or bituminous paving depth gauge 10 of the present invention when set at zero is approximately five feet. In this manner the measuring portion of the apparatus of the present invention is placed at eye level for easy reading of the depth or the mat. Bituminous paving depth gauge 10 of the present invention is preferably made from aluminum so that it is light weight and portable. Thus, it may be carried in a vehicle or in a case mounted on the spreader. This arrangement gives personnel easy access to the apparatus of the present invention for measuring the bituminous paving layer thickness or depth.
Referring now to FIG. 2, an isometric view of the bituminous paving depth gauge 10 of FIG. 1 is illustrated. As can be seen, depressible rod 14 fits closely but loosely in brackets 32 A, 32 B and 32 C. This is to allow indicator 16 on rod 14 to move or slide easily between the zero point and the maximum depth point in graduated section 30 . However, depressible rod 14 its snugly enough in brackets 32 A, 32 B and 32 C so that depth gauge 10 may be easily carried from measuring point to measuring point without banging or flopping back and forth. Depressible rod 14 is shown as being approximately one inch from support system 12 . This distance is merely for convenience and may be any distance as long as rod 14 moves freely vertically without interference from support system 12 .
The present invention provides a top reading bituminous paving depth gauge for measuring the thickness of paving layers. The measuring device of the present invention as described has a depressible rod operatively associated with a support system. The depressible rod fits in the rod support system. The rod support system has an upper portion having a graduated measuring gauge and a lower portion including a bottom support device fixed to its lower end upon which the support system rests.
As has been illustrated, the depressible rod portion of the present invention has no washer that would prevent the rod from going the complete depth of the mat. The rod is preferably five feet long and has a cone shaped bottom to allow insertion into the bituminous paving layer or mat. With the narrowed tip of the cone shaped bottom at the end of the rod, the rod is pushed into the bituminous paving with little effort by the operator of the device. The support system includes brackets through which the rod slides. The support system also includes a graduated mark section, preferably at eye level, which remains stationary while the rod is inserted into the pavement mat.
While there has been illustrated and described a particular embodiment 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. | A top reading bituminous paving depth gauge is used to determine the thickness of paving layers. The gauge comprises a depressible rod operatively associated when a rod support system comprising an upper portion having a graduated measuring gauge fixed on the rod support system and a bottom support devise fixed to the lower end of the rod support system. The bottom or the support device acts as a foot for the measuring gauge and also acts to receive the lower portion of the depressible rod. The top reading bituminous paving depth gauge operates without any washers on the measuring depressible rod to prevent false measurements due to the presence of large aggregates. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to enhanced trajectory tracking of an automobile and, more particularly, to a method for relative positioning of a host vehicle with respect to surrounding static obstacles and moving targets which uses object detection data along with vehicle dynamics data to compute a closed loop trajectory of the host vehicle, and uses the trajectory in path planning for collision avoidance or other purposes.
2. Discussion of the Related Art
Many vehicles now include systems which can actively control the path of the vehicle—for applications such as collision avoidance. These systems, when they detect a need to alter the path of the vehicle, will determine a desired new path for the vehicle to follow, implement braking and/or steering commands to achieve the desired path, monitor the actual trajectory of the vehicle relative to the desired path, and make further corrections to follow the desired path—all in real time.
In such systems, it is essential that a reliable method of monitoring the actual trajectory of the vehicle is available. Many vehicles equipped with such systems use vehicle dynamics sensors—including velocity, yaw rate and acceleration sensors—as one means of calculating actual vehicle trajectory. However, vehicle dynamics or “dead reckoning” calculations are susceptible to cumulative error. Therefore, another source of vehicle trajectory data is needed—preferably a source which does not accumulate error like the vehicle dynamics data. Global Positioning System (GPS) data is commonly used as the second source of vehicle trajectory data in vehicle path planning systems. However, some vehicles are not equipped with GPS receivers, and even vehicle which are equipped with GPS receivers will sometimes have no signal available—such as in tunnels, “urban tunnels” and roads with tall and dense surrounding tree cover.
SUMMARY OF THE INVENTION
In accordance with the teachings of the present invention, a method is disclosed for determining an actual trajectory of a vehicle using object detection data and vehicle dynamics data. An object detection system identifies point objects and extended objects in proximity to the vehicle, where the point objects are less than a meter in length and width. An updated vehicle pose is calculated which optimally transposes the point objects in the scan data to a target list of previously-identified point objects. The updated vehicle pose is further refined by iteratively calculating a pose which optimally transposes the extended objects in the scan data to a target model of previously-identified extended objects, where the iteration is used to simultaneously determine a probability coefficient relating the scan data to the target model. The updated vehicle pose is used to identify the actual trajectory of the vehicle, which is compared to a planned path in a collision avoidance system.
Additional features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a vehicle with path planning and closed-loop trajectory control using vehicle dynamics and object detection data as input;
FIG. 2 is a block diagram of a vehicle path planning system with closed-loop trajectory control using vehicle dynamics and object detection data as input;
FIG. 3 is an illustration of a vehicle determining its position relative to detected objects, including point objects and extended objects; and
FIG. 4 is a flowchart diagram of a method for vehicle path planning and trajectory following with closed-loop control, using vehicle dynamics and object detection data as input.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The following discussion of the embodiments of the invention directed to a method for determining an actual trajectory of a vehicle using object detection data and vehicle dynamics data is merely exemplary in nature, and is in no way intended to limit the invention or its applications or uses.
Some vehicles are now equipped with collision avoidance systems which can take control of vehicle steering and braking in situations where a vehicle collision appears to be imminent. Collision avoidance systems determine a desired path for the vehicle to take in order to avoid the collision, measure actual vehicle trajectory, and make steering/braking corrections in real time. Actual vehicle trajectory is typically determined in these systems using a combination of vehicle dynamics data and GPS data. However, in vehicles which are not equipped with a GPS receiver, and in situations where GPS data is not available due to sky visibility obstructions, another source of vehicle position data is needed.
FIG. 1 is a schematic diagram of a vehicle 10 with path planning and closed-loop trajectory control using vehicle dynamics and object detection data as input. The vehicle 10 includes a vehicle dynamics module 20 which estimates vehicle motion based on vehicle dynamics calculations, using input from a plurality of sensors 22 . The sensors 22 (one shown) may include a vehicle speed sensor, a yaw rate sensor, lateral and longitudinal acceleration sensors, and possibly others. The vehicle 10 also includes an object range data module 30 , which provides object range data from one or more object detection sensor 32 .
The object detection sensor 32 may use any suitable object detection technology, including short-range radar, long-range radar, LIDAR, and/or camera images. In particular, synthetic aperture radar systems are now becoming available where the radar antenna is a thin sheet which can be placed on or inside of a vehicle body panel or bumper fascia, thus making radar-based object detection more cost-effective. Using any desirable combination of object detection sensors 32 , the object range data module 30 provides object range data which is updated at time intervals such as 100 milliseconds (ms). The vehicle 10 also includes a vehicle pose estimation module 40 , a path planning module 50 and a vehicle control module 60 , which are discussed further below.
FIG. 2 is a block diagram of a vehicle path planning system 70 with closed-loop trajectory control using vehicle dynamics and object detection data as input. The path planning system 70 of FIG. 2 shows how the modules 20 - 60 are inter-related. As discussed above, the vehicle dynamics module 20 provides vehicle motion data to the vehicle pose estimation module 40 , while the object range data module 30 provides object range data to the vehicle pose estimation module 40 . The vehicle pose estimation module 40 uses the vehicle dynamics data and the object range data to estimate the updated vehicle pose, or position and orientation, at each time step. The path planning module 50 provides a desired path for the vehicle 10 to follow—such as for the purpose of collision avoidance. The actual vehicle trajectory data from the vehicle pose estimation module 40 and the desired vehicle path data from the path planning module 50 are provided to a summing junction 55 , where the difference is provided to the vehicle control module 60 which makes further adjustments to steering and braking commands in order to minimize the difference between the actual vehicle trajectory and the desired vehicle path.
It is to be understood that the vehicle dynamics module 20 , the object range data module 30 , the vehicle pose estimation module 40 , the path planning module 50 and the vehicle control module 60 are comprised of at least a processor and a memory module, where the processors are configured with software designed to compute desired and actual vehicle position and issue vehicle control commands based on the described inputs. The logic and calculations used in the vehicle pose estimation module 40 , in particular, will be discussed in detail below.
It is to be further understood that the features and calculations of the vehicle pose estimation module 40 , the path planning module 50 and the vehicle control module 60 could be allocated differently than described herein without departing from the spirit of the disclosed invention. For example, although the functions of the modules 40 , 50 and 60 are described as being distinct throughout this disclosure, they could in fact all be programmed on the same processor. That is, all vehicle position planning, trajectory estimation and control functions could be performed in a single physical device with one or more processors.
FIG. 3 is an illustration of the vehicle 10 determining its position relative to detected objects, including point objects (such as light poles and tree trunks) and extended objects (such as vehicles and concrete barriers). A local world coordinate frame 100 is established with origin O and X-Y axes. The vehicle 10 is located at a position (x H ,y H ) and has a heading angle of θ H with respect to the local world coordinate frame 100 . A method of continuously updating the vehicle pose (consisting of x H , y H and θ H ) based on the detected objects is detailed below.
The calculations described in the following discussion are performed in the vehicle pose estimation module 40 unless otherwise noted. At each time step, a scan map S is received from the object range data module 30 , and S is projected to the local world coordinate frame 100 based on a known previous pose P=(x H ,y H ,θ H ). The scan map S is then grouped into a list of clusters, and each cluster is classified as a point object (which may be defined as those objects with length and width less than 1 meter) or an extended object (if larger). The objective of the method is to predict the new host vehicle pose from the observed relative motion of the scan objects.
A predicted new vehicle pose P′=(x′ H ,y′ H ,θ′ H ) can be computed based on vehicle dynamics and the previous pose P, as follows:
x′ H =x H +ν xH ΔT
y′ H =y H +ν yH ΔT
θ′ H =θ H +ω H ΔT (1)
Where ν xH is the vehicle longitudinal velocity, ν yH is the vehicle lateral velocity, ω H is the vehicle yaw rate and ΔT is the time step increment. Throughout the following discussion, it is important to distinguish between P′, which is the preliminary predicted new vehicle pose based on vehicle dynamics, and other variables such as P* and P″, which are new vehicle poses produced by the calculations based on the object scan data.
A first estimation of the new vehicle pose, producing a value P*, will be made based on the point objects, which are indicated by bracket 110 in FIG. 3 . For each point object in the scan data (represented by circles 112 ), a center of mass o i =(x i ,y i ) is computed, and the point object is matched with a current registered target (represented by stars 114 ) in a point target list {t l }, where each target in {t l } is represented by its position (x l ,y l ). The new pose P* can be found by using a least-squares optimization, as follows:
P * = argmin P ′ ∑ i o i - T P ′ ( t l ( i ) ) σ l ( i ) 2 ( 2 )
Where t l(i) is the corresponding registered target associated with the point object o i , T P′ (t l(i) ) is the projection of t l(i) under rigid transformation P′ determined by the vehicle position, and σ l(i) is the measurement error covariance for the corresponding target t l(i) .
A hit count k l is tracked for each registered target t l . The hit count k l is incremented by one for each registered target t l which is matched by a point object o i from the scan data. If k l is greater than a predetermined threshold, such as four, then the target t l is marked as being matured. If o i does not match with any registered target t l in the map, a new target will be generated with k l =1.
The point target list {t l } can be updated using simultaneous localization and mapping techniques, as follows:
t l ′ = 1 κ l T P * - 1 ( o i ) + κ l - 1 κ l t l ( 3 )
Where t′ l is the new target location (x,y), T P* −1 is the inverse transformation of P*, and o i is the point object from the current scan which matches the registered target t l . The measurement error covariance for the corresponding target t l is updated as:
σ l 2 ′ = 1 κ l ( t l - T P * - 1 ( o i ) ) 2 + κ l - 1 κ l σ l 2 ( 4 )
Where o i is the point object associated with t l . Also, as mentioned above, the hit count k l is updated by incrementing k l =k l +1.
The new vehicle pose P* from Equation (2) is the output from the analysis of point objects described above.
A second estimation of the new vehicle pose can then be performed based on the extended objects, which are indicated by bracket 120 in FIG. 3 . The objective of the extended object calculation is to find the best transformation from an existing model M of extended targets (point clouds) to a current scan S of objects (concatenated clusters). The extended object calculation is iterative in nature because of the ambiguity in associating individual scan points s j in S (represented by circles 122 ) to model points m k in M (represented by stars 124 ).
The iteration is started by assuming an initial value of a pose P (0) is equal to the new vehicle pose P* from Equation (2) of the analysis of point objects. If no point objects are available in the scan data, then P (0) can be set equal to P′ from the vehicle dynamics data. The extended object vehicle pose calculation is then iteratively computed until convergence, as follows:
P ( n + 1 ) = argmin P ( n ) ∑ j , k  j k s j - T P ( n ) ( m k ) σ 2 ( 5 )
Where P (n+1) is the next iterative value of the vehicle pose, s j and m k are extended object scan points and model points, respectively, T P (x) is the operator to apply a rigid transformation P to a point x, and the coefficient matrix  jk , computed by an Expectation-Maximization (EM) algorithm, is the probability that s j is a measurement of m k , and Σ k  jk =1.
In Equation (5), σ is a bandwidth parameter, which is a predefined positive constant. An implementation of  jk can be:
 j k = c exp ( - s j - m k σ 2 ) ( 6 )
Where c is the normalizing factor. After convergence or a certain prescribed number of iterations, an extended object-based transformation P″ is defined as P″=P (n+1) from Equation (5).
If a model point m k is measured by a scan point (e.g., s j ), the hit count for m k is increased by one. When a scan point s j does not match with any model point, the scan point s j is added to the model M and its hit count is set equal to one. When a model point m k is not matched by any scan point in S, its hit count is decreased by one. Model points with hit count less than one are periodically deleted.
The extended object target model M can be modeled as a Gaussian Mixture Model (GMM) distribution:
p ( x;M )=Σ k=1 n M p ( x|m k ) (7)
where
p ( x | m k ) = 1 ( 2 πσ 2 ) 3 2 exp ( - x - m k 2 2 σ 2 ) ( 8 )
And xεR 2 , a point in 2-D Cartesian coordinate frame.
In the above equations, the parameter m k has a normal distribution,
p ( m k ) = N ( v k , σ 2 η k ) ( 9 )
Where ν k is the mean,
σ 2 η k
is the variance, and ν k and η k are parameters of the model M. The update rules for ν k and η k are:
v k ′ = ρ k s _ k + η k T P ″ ( v k ) ρ k + η k ( 10 )
and
η′ k =η k +ρ k (11)
Where ρ k =Σ j  jk , and s k =Σ j  jk s j /ρ k .
To summarize the above discussion, a vehicle pose P* is computed from vehicle dynamics data and point objects in the scan data, and a vehicle pose P″ is computed from the vehicle pose P* and extended objects in the scan data. Different algorithms can be employed for using either the vehicle pose P* or the vehicle pose P″, or a combination of the two. For example, if point objects are dominant in the scan data, then the vehicle pose P* could be used as the updated vehicle position for trajectory tracking purposes. Conversely, if extended objects are dominant in the scan data, then the vehicle pose P″ could be used as the updated vehicle position for trajectory tracking purposes. As another alternative, a fusion calculation could be performed using both point and extended objects, as follows:
P ** = argmin P ( n ) ( ∑ i o i - T P ( n ) ( t l ( i ) ) σ l ( i ) 2 + ∑ j , k  j k s j - T P ( n ) ( m k ) σ 2 ) ( 12 )
Where the first summation is for the point-based objects as shown in Equation (2) and the second summation is for the extended objects as shown in Equation (5). Equation (12) is solved iteratively because of the ambiguity in associating the extended object scan points s j to model points m k , as discussed previously. After convergence or a certain prescribed number of iterations, an overall, fused, scanned-object-based transformation P** is yielded by Equation (12).
FIG. 4 is a flowchart diagram 150 of a method for vehicle path planning and trajectory following with closed-loop control, using vehicle dynamics and object detection data as input. As described previously, the method of the flowchart diagram 150 is performed by algorithms in the vehicle pose estimation module 40 . At box 152 , new scan data is obtained from the object range data module 30 . At box 154 , host vehicle motion data is provided by the vehicle dynamics module 20 . Using the host vehicle motion data and the object scan data, the ground speed of scanned targets can be estimated at box 156 . At decision diamond 158 , it can be determined if moving objects are present in the scan data. If it is determined that only moving objects are present in the scan data, then the process loops back to the box 152 to receive the next time increment of scan data, as moving objects may not be useful for the trajectory tracking purposes discussed above. If moving and stationary objects are identified, the moving objects may be disregarded.
At decision diamond 160 , it is determined whether point objects, extended objects, or both are present in the scan data. At box 162 , point objects in the scan data are used to calculate the new vehicle pose P* using Equation (2). The point object calculations at the box 162 also use the vehicle dynamics data from the box 154 , as discussed in detail previously. At box 164 , extended objects in the scan data are used to calculate the new vehicle pose P″ using Equation (5). The extended object calculations at the box 164 also use the point-object-based pose estimation P* from the box 162 , as discussed in detail previously.
At box 166 , an overall vehicle pose estimation is determined from the scanned object data, using the pose estimations from the boxes 162 and 164 as input. As discussed above, the overall vehicle pose estimation may simply use the value calculated at the box 162 or 164 if point objects or extended objects are dominant in the scan data. Alternatively, a fusion calculation can be performed at the box 166 , using Equation (12). The overall vehicle pose estimation is output from the box 166 , where it is used by the vehicle control module 60 for vehicle trajectory control. The process then loops back to the box 152 to receive the next time increment of scan data.
Using the methods disclosed herein, closed-loop vehicle trajectory control can be implemented using object scan data as input. By eliminating the need for GPS data for vehicle trajectory tracking feedback, system cost can be reduced, and the issue of temporary unavailability of GPS signals is avoided. Furthermore, the ability to process both point objects and extended objects provides a robust solution, while still being implementable in real-time processors onboard the vehicle.
The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims. | A method for determining an actual trajectory of a vehicle using object detection data and vehicle dynamics data. An object detection system identifies point objects and extended objects in proximity to the vehicle, where the point objects are less than a meter in length and width. An updated vehicle pose is calculated which optimally transposes the point objects in the scan data to a target list of previously-identified point objects. The updated vehicle pose is further refined by iteratively calculating a pose which optimally transposes the extended objects in the scan data to a target model of previously-identified extended objects, where the iteration is used to simultaneously determine a probability coefficient relating the scan data to the target model. The updated vehicle pose is used to identify the actual trajectory of the vehicle, which is compared to a planned path in a collision avoidance system. | 1 |
FIELDS OF THE INVENTION
This invention relates to a tubing hanger or dognut and a tubing spool used in servicing oil or gas wells. The apparatus can be used to hold a downhole packer in the packed position or to compensate for a change in length of the tubing.
BACKGROUND OF THE INVENTION
When equipping an oil or gas well or an injection well for production or other use, it is often required to use a downhole packer which is connected to the wellhead by tubing which is held under tension. The tension is required to hold the packer in the packed position, or to compensate for a change in length of the tubing if hot liquid or gases move up or down the tubing. Often, it is required to carry out the installation of this equipment while the well is under pressure from the geological zone of interest.
In a conventional tubing hanger system, once the downhole packer is in place, tension is then put on the tubing by pulling it. To install the tubing hanger on the well, the tubing string is stretched out of the tubing and held by slips. Once the tubing hanger has been installed, the slips are released and the tubing hanger is lowered into place in the conical section of the tubing spool and secured with dog screws. The packing ring is then tightened by turning in the packing bolts. The packing then seals the cavity in the hanger and the casing from anything above the tubing hanger.
When using a conventional tubing spool and tubing hanger system in a well under pressure, the packer and tubing are installed by an operation called "snubbing" where items are pushed into the well against the well pressure with suitable above ground equipment. In order to keep the pressure confined, blow out preventers are utilized. Once the tubing hanger has been installed on the tubing in the same manner as set out above, it is lowered through a first upper blow out preventer which has been opened to allow its passage into the annular space between the blow out preventers. During this operation, the second or lower blow out preventer is sealing the pressure in the well as the tubing slips through it. Once the blow out preventer is closed, the lower blow out preventer is opened to allow the passage of the dognut which is then seated in the conical part of the tubing spool. In order to set the packing, it is then necessary to remove the blow out preventer stack. There is always a problem at this stage as the pressure may not be sealed by the loose packing or primary packing. A second problem associated with the conventional tubing hanger system is that the stretch required to get the tubing through the blow out preventer stack is quite long and in shallow wells this becomes a critical factor in having the proper tension in the tubing with the tubing hanger in its final position in the hanger.
SUMMARY OF THE INVENTION
The present invention provides a tubing spool-tubing hanger dognut system wherein the tubing hanger can move through the tubing spool and be seated and sealed from outside the tubing spool. This system overcomes the problem associated with the conventional tubing spool-hanger system since the tubing hanger is put in place on the tubing and the packer latched in place in the well before the tensioning of the tubing takes place.
According to a broad aspect, the invention relates to a combined tubing spool and hanger assembly for use in servicing oil and gas wells. The assembly comprises a tubing spool for connection to the upper end of the well casing, the spool including an internal annular portion of reduced diameter with respect to the remainder of the internal surface of the spool and sized to allow the tubing hanger to pass therethrough. Means are provided for locating the tubing hanger in the reduced diameter portion of the spool and means are also provided for releasably securing the tubing hanger in the spool and which comprises a plurality of circumferentially spaced recesses in the side wall of the hanger and a corresponding plurality of locking pins positioned in the spool and being engageable with the recesses to prevent movement of the hanger in the spool. An annular, resilient packing element is provided on the hanger and, when compressed, engages and seals against the annular portion of reduced diameter in the spool. Means are provided on the hanger for expanding the resilient packing element into sealing engagement with the spool and means are also located in the wall of the spool to actuate the expanding means. The hanger locating means, releasable securing means and the expander actuating means are all operable from outside of the tubing and hanger assembly.
Once the tubing hanger has been installed on the tubing in the usual manner, it is lowered through the tubing spool. Once the packer is latched and packed off in the well casing, the tubing hanger and tubing string will be pulled upward and the tubing thus stretched. Locking pins located in the tubing spool will then be turned in so as to engage the locking recesses of the tubing hanger, thus locking it in place. Dog pins also located in the tubing spool are then turned in to expand the packing element and seal the spaces below and above the tubing hanger.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view of the tubing spool and tubing hanger after the installation of the tubing hanger on the tubing;
FIG. 2 is a vertical sectional view of the tubing spool and tubing hanger with the latter in the low position after the packer has been set in place;
FIG. 3 is a vertical sectional view of a tubing spool and tubing hanger when the tubing is being stretched;
FIG. 4 is a vertical sectional view of the tubing spool and tubing hanger after the tubing hanger has been locked in place and the spaces above and below it sealed;
FIGS. 5, 6 and 7 are cross-sectional views taken along lines 5--5, 6--6 and 7--7, respectively, of FIG. 4;
FIG. 8 is an enlarged, fragmentary sectional view of a portion of the tubing hanger;
FIGS. 9 and 10 are cross-sectional views of the locking/locating pin and dog pin respectively; and
FIGS. 11, 12 and 13 are schematic sectional views showing the use of the present invention in a well under pressure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1, a tubing spool-tubing hanger arrangement includes a tubing spool illustrated generally at 10 which is adapted for connection to the upper end of a well casing 12, a sub 14 having a packing element 16 on the lower end thereof includes, above the packing element, a tubing hanger 18. This assembly is lowered through the tubing spool 10 so that the packing element enters the area of the casing that is desired to be packed off and the tubing hanger is adapted to seal off the upper end of the spool.
The tubing hanger 18 is of substantial thickness and is circular or cylindrical in configuration and is provided with at least one locating slot 20 on its upper periphery as well as a plurality of sockets or locking holes 22. Usually three or more of the locking sockets are provided and spaced evenly around the periphery of the tubing hanger. A flexible, ring shaped packing element 24 is provided roughly centrally of the tubing hanger around the circumference thereof and, while the packing ring 24 is illustrated as a unitary element, it can be made up of separate rings or the like. This packing element 24 is held in place on the tubing hanger 18 by an energizing ring 26 by means of lock screws 28 as shown more clearly in FIG. 8. Preferably, three or more lock screws 28 are spaced above the periphery of the energizing ring.
The tubing spool 10 is of a standard size, dictated by well requirements and industry standards. Spool 10 has an inside diameter such that the tubing hanger 18 and its associated elements will slide through the packing area 30 of the spool and will be a non-engaging fit in the space 32 there below. The packing area 30 includes bevelled shoulders 34 which serve to guide the tubing hanger to the center of the spool when it is moved through the packing area.
One or more locating pins 36 and locking pins 38 are located on the periphery of the upper end of the spool 10 and they match and cooperate with slot 20 and locking sockets 22 respectively provided for them on the tubing hanger 18. Dogpins 39 are located on a flange 40 of the spool.
During installation, the locating pins 36, locking pins 38 and dogpins 39 are all backed off to their outermost positions so that they will not interfere with the free movement of the tubing hanger 18 through the spool 10 as seen in FIG. 1. The tubing hanger 18 is installed on tubing 14 in a conventional manner and is lowered through the spool 10 on the sub by means of a hook 42 which is suspended by outside means, as shown in FIG. 2. The packer 16 is then latched and packed off in the well casing 12 in the conventional manner. The tubing hanger 18 is now in the position shown in FIG. 2 and, depending on the length of stretch required for the proper tensioning of the tubing 14, the tubing hanger 18 may even be in a position shown by the phantom line in FIG. 2.
The locating pin 36 is then turned into the engaging position as shown at the upper end of FIG. 2 and the tubing hanger 18 and tubing string is now pulled upwardly by the sub 44 and hook 42. With the packer 16 latched in place, the tubing is upwardly stretched until the slot 20 in the tubing hanger engages the locating pin 36 and the tubing hanger terminates in the position shown in FIG. 3. The slot 20 in the tubing hanger is used for locating the tubing hanger in the spool 10 if the hole in the center of the tubing hanger is off-center or if more than one tubing string is in the tubing hanger.
The locking pins 38 are now turned inwardly to engage the locking sockets 22 in the tubing hanger, as shown in cross-section in FIG. 5, and the tubing hanger 18 is now locked in place in the spool 10. Subsequently, the dogpins 39 which have conical inner ends 46, are turned inwardly so that the conical inner ends 46 engage the bevelled periphery 48 of the energizing ring 26 thereby forcing the ring upwardly, the upward movement of the ring 26 compressing the packing ring 24 so that it tightly engages the walls 30 in the upper end of the spool 10, thereby sealing the space below and above the tubing hanger 18. The tubing spool 10 is now setup to accept any of the usual equipment that is required by the end user.
Advantages of the present invention when used in a pressurized well, will be appreciated from a review of FIGS. 11, 12 and 13.
FIG. 11 shows the tubing hanger 18 being run on the last joint of the tubing 14. An upper blow-out preventer 50 and a lower blow-out preventer 52, with an intermediate spool 54, are mounted on top of the tubing spool 10. The upper blow-out preventer 50 is opened and the bottom blow-out preventer 52 is closed.
In FIG. 12, the tubing hanger has been lowered through the upper blow-out preventer which is now closed and the lower blow-out preventer 52 being opened so that the tubing hanger 18 travels down through the spool 10. The packer 16 is then latched and packed off and the sub is now pulled upwardly to set the tension in the tubing and the tubing hanger 18 is seated, locked in place and sealed as shown in FIG. 13. The blow-out preventer equipment can now be safely taken off and the required equipment put on the well head. It will be noted that the stretched length of the tubing 14 can be set exactly as required due to the fact that the tubing hanger 18 is put in place in tubing 14 and the packer 16 latched in place in the well before the tensioning of the tubing takes place. The length of tubing in the BOP stack is not a factor in the final tubing length.
Those skilled in the art will appreciate the various features, characteristics and advantages of the present invention have been set forth herein or are readily realizable from the detailed description of the illustrated embodiment. However, the disclosure is illustrative and various changes may be made while utilizing the principles of the present invention in falling within the scope of the invention as expressed in the appended claims. | There is disclosed an apparatus including a tubing spool and tubing hanger which overcomes problems associated with servicing of oil and gas wells under pressure. In the invention, a tubing hanger can move through a tubing spool and be seated and sealed from the outside the tubing spool. The tubing hanger includes a flexible packing element with means for engaging and expanding the element to the tubing hanger in the tubing spool and a plurality of locking means adapted to secure the dognut in relation to the tubing spool. | 4 |
RELATED APPLICATIONS
[0001] This application incorporates by reference the contents of co-pending patent application Ser. No. 12/684,597, filed Jan. 8, 2010, entitled “Rodless Dispenser.” This application also incorporates by reference the contents of co-pending patent application Ser. No. 12/703,613, filed Feb. 10, 2010, and which is entitled “Piston and Piston Rod for a Rodless Dispenser.” Also incorporated by reference is application Ser. No. 12/703,471 filed Feb. 10, 2010, and entitled, “Rodless Dispenser for Extrudable Materials Having a Contents Indicator.”
BACKGROUND
[0002] Mechanical dispensers for viscous or extrudable materials include common, piston-type caulking guns found in any hardware store as well as small, hand-held devices for rolling up a flexible tube, such as the tubes that dispense toothpaste. Most extrudable material dispensers employ a piston attached to one end of an elongated piston rod. The piston is advanced through a half or partial-cylinder holder, the shape of which is reminiscent of a trough, the function of which is to hold a cylindrical canister of extrudable material.
[0003] Extrudable material in a canister is forced from the canister through a canister tip by driving a canister-internal piston installed into the “bottom” of the canister. The piston in the bottom of the canister is hereafter referred to as a canister piston.
[0004] The canister piston drives extrudable material from the canister when the canister piston is driven through the canister by the piston attached to the piston rod. The piston rod is driven by a pistol grip mechanism that forms part of the dispenser. The pistol grip mechanism can be attached to either a ratcheting or ratchetless transmission device. Actuation of the pistol grip causes the piston rod to be advanced into the cylinder, which in turn drives the first piston (attached to the connecting rod) into the second piston (in the bottom of a canister of extrudable material) forcing extrudable material from the dispensing tube. As the first piston moves away from the transmission device and into the dispensing tube, extrudable material is forced from the tip of the canister.
[0005] A problem with prior art caulking guns or other dispensers for extrudable materials is that the push rod is relatively long and extends outwardly to make the dispenser unwieldy. The extended rod also makes the device difficult to store or set down between uses, especially when such devices are used in close quarters, as often happens when the devices are used in restaurants to dispense condiments and other extrudable food products. A dispenser for dispensing extrudable material which eliminates the push rod would be an improvement over the prior art.
BRIEF DESCRIPTION OF THE FIGURES
[0006] FIG. 1 is a perspective view of an alternate embodiment of a rodless dispenser.
[0007] FIG. 2 is an exploded view of the rodless dispenser.
[0008] FIG. 3 is a left side view of a drive mechanism.
[0009] FIG. 4 is a right side view of the drive mechanism.
[0010] FIG. 5 is a perspective view of the right side of the drive mechanism.
[0011] FIG. 6 is a left side view showing the push chain, piston and drive mechanism.
DETAILED DESCRIPTION
[0012] Referring to FIG. 1 , the rodless dispenser 100 is comprised of an elongated tube support 102 , a push chain drive mechanism 104 located inside a housing 106 . The housing 106 is attached to the elongated tube support 102 . A handle 108 is formed as part of or which is attached to the housing 106 and an actuating trigger 110 . The housing 106 has right and left substantially planar sides 107 , 109 , which cover and protect components inside the housing 106 . A piston 112 is attached to and driven by a push chain, not visible in FIG. 1 . At least part of the push chain is stored in a push chain magazine 114 attached to or formed as part of the tube support 102 .
[0013] When the trigger 110 is pulled toward or into the handle 108 , the piston 112 advances incrementally into the tube support 102 . When a tube of extrudable material is placed into the tube support, the piston 112 will drive the material from the tube so that the material can be dispensed. A pair of ratcheting pawls inside the housing, which comprise the drive mechanism, are configured to allow the piston to be advanced incrementally with each actuation of the trigger and held in position. The drive mechanism thus advances the piston yet prevents it from retreating in response to the opposing force that the piston “sees” when it pushes against extrudable material.
[0014] When the piston needs to be retracted, such as when a tube needs to be removed from the tube support, the ratcheting pawls are configured to be released together by a single actuator. The actuator that releases both pawls, and which releases the piston, is embodied as one end of a pawl that is configured to hold the piston in place.
[0015] FIG. 2 is an exploded view of the rodless dispenser 100 . The tube support 102 can be seen to be comprised of a roughly half cylinder or semi-cylinder 200 having first and second ends, 202 , 204 . The push chain magazine 114 is formed from a trough 206 located at the bottom of the semi-cylinder 200 . A substantially round end panel 218 is sized, shaped and arranged to receive and be affixed to the first end 202 of the semi-cylinder 200 . The end panel 218 is considered herein to comprise a first end of the support tube 102 . A tube-retaining ring 220 having a centrally-located opening or hole 222 is attached to the second end 204 of the semi-cylinder 200 and forms a second end of the tube support 102 .
[0016] Several, substantially U-shaped push chain links 208 are joined to each other to form a push chain 210 having first and second opposing ends 212 , 214 . The first end 212 of the chain 210 is attached to a bottom end of a piston rod 224 . The piston rod 224 is attached to the bottom side 226 of the piston 112 , i.e., the side of the piston 112 oriented toward the housing 106 and drive mechanism 104 . The first end 212 of the chain 208 and the piston rod 224 extend through a rectangular hole or opening 226 formed in the substantially circular-shaped end panel 218 .
[0017] Inside the housing 106 , the chain 210 and its links 208 wrap part way around a push chain sprocket not visible in FIG. 2 , and extend into the magazine 114 . Inside the magazine, 114 , the second end 214 of the push chain 210 is attached to a substantially U-shaped push chain retractor 228 .
[0018] The U-shaped push chain retractor 228 is formed to fit over the vertical side surfaces 230 of the magazine 114 . The push chain retractor 228 is thus configured to be graspable, i.e., capable of being grasped, by a thumb and an index finger or other digit. The retractor 228 is also formed with a post or tab 232 that extends upwardly through an elongated slot 234 formed into the bottom surface 236 of the magazine 114 . Grasping the retractor 228 and sliding it or translating the retractor 228 back and forth along the length of the magazine 114 thus moves the chain 210 and its links 208 into and out of the magazine 114 , so long as the pawls described herein are disengaged to allow the chain to move freely.
[0019] Each of the chain links 208 is substantially U-shaped. Each link has a “first” side that opens into the U-shaped link. The first side is also sized and shaped to receive a “tooth” of a chain sprocket. A second side is substantially planar.
[0020] The links are sized, shaped and arranged such that the first sides of the links are able to rotate or fold toward each other, enabling the links and the chain they form to wrap around a chain sprocket. The first sides of the links are not able to rotate or fold away from each other in the opposite direction but instead lock to become rigid and substantially columnar, as long as the links are urged to rotate the open sides away from each other.
[0021] FIG. 3 is a side view of the drive mechanism 104 . The drive mechanism 104 is shown inside the housing 106 , but the left side 109 of the housing is shown as being removed in FIG. 3 in order to reveal components of the drive mechanism 104 .
[0022] A substantially U-shaped horizontal axle support 300 is attached to and extends away from the first end 218 of the tube support 102 and part way into the housing 106 . The left and right (first and second) sides 302 , 304 of the axle support 300 hold corresponding ends of a first axle 306 , which extends into the plane of FIG. 3 .
[0023] The first end 308 of axle 306 is engaged with a hole or opening 310 formed into the first end 314 of the trigger 110 . The trigger 110 extends downwardly at an angle theta relative to the handle 108 .
[0024] The first end 314 of the actuating trigger 110 is formed or provided with a substantially U-shaped drive pawl support arm 318 having a slot between the opposing and substantially parallel sides 319 of the support arm 318 . The drive pawl support arm 318 and its sides 319 extend laterally away from the axle 306 and opening 310 in the first end 314 of the trigger 110 such that rotation of the trigger 110 around the axle 306 also rotates the entire drive pawl support arm 318 through the same angle of rotation.
[0025] The far or distal ends of the sides 319 of the drive pawl support arm 318 are provided with concentric holes 320 sized, shaped and arranged to receive a drive pawl support axle 322 . The drive pawl support axle 322 extends into both of the sides 319 of the U-shaped drive pawl support arm 318 .
[0026] The drive pawl 324 fits between the sides 319 of the drive pawl support arm 318 . The drive pawl 324 has a hole, not visible in the figures, through which the drive pawl axle 322 extends and by which the drive pawl 324 is rotatably supported in the drive pawl support arm 318 . Rotatably supported in the drive pawl support arm 318 means that the drive pawl 324 is able to rotate on, or rotate with, the drive pawl support axle 322 while the drive pawl 324 is inside the U-shaped drive pawl support arm 318 .
[0027] The drive pawl 324 has a first end 326 that is able to reach into and engage notches 328 in a fine-toothed drive wheel 330 responsive to the drive pawl rotation through the small angle. (The terms, “fine-toothed drive wheel” “drive gear” and “drive wheel” are used interchangeably hereinafter.) An opposing second end 328 of the drive pawl 322 extends downwardly from the drive pawl support arm 318 .
[0028] The toothed wheel 330 is circular. Its outside surface is formed or provided with equidistant, equally-spaced notches 328 . The drive pawl 322 is biased by a torsion spring 323 , best seen in FIG. 4 , such that the first end 324 is normally engaged with a notch 328 .
[0029] When the second end 113 of the trigger 110 , which is attached to the first axle 306 , is pulled toward the handle 108 , the trigger 110 rotates around the geometric axis of the first axle 306 . Such actuation of the trigger 110 also rotates the drive pawl support arm 318 in the same direction. Rotation of the drive pawl support arm 318 in the direction of R will of course also rotate the drive pawl support axle 322 and the drive pawl 324 in the same direction. Since the first end 326 of the drive pawl 324 is biased to engage notches in the drive wheel 330 , rotation of the actuating trigger 110 around the first axle 306 rotates the drive wheel 330 in the same direction. The teeth in the drive wheel are cut or formed at an angle, such that the drive pawl is able to exert force on the drive wheel in one direction only.
[0030] As used herein, a ratchet is a mechanism comprised of a bar or pawl, which drops into successive inclined teeth of a gear so that one-way motion can be imparted to the gear by movement of the bar or pawl into the teeth of the gear.
[0031] The trigger 110 is biased by a spring 402 inside the handle and inside the trigger to move away from the handle 108 . The spring 402 is preferably a torsion spring, i.e., a spring that provides torque, but could also be provided by a compression spring, i.e., a spring that provides either a compressive force or a tensile force.
[0032] When the trigger 110 is pulled toward the handle 108 , the drive pawl engages a tooth in the drive gear and rotates the gear by the rotation of the trigger 110 around the axis of the first axle 306 . When the trigger is released, the drive pawl and the driver rotate in an opposite direction, however, because of the angle at which the teeth in the drive wheel are oriented, the first end of the drive pawl slips over the teeth in the drive gear without moving the drive gear. The drive pawl thus acts as a ratchet to the drive gear. Repeatedly squeezing the trigger 110 toward the handle 108 will thus rotate the drive wheel in one direction.
[0033] Still referring to FIG. 3 , there is a second pawl 340 that is rotatably supported on a third axle. The third axle 346 is supported by the sides 107 , 109 of the housing 106 .
[0034] The second pawl 340 , which is considered to be a locking/unlocking pawl, has a first end 342 that extends away from the third axle 346 and configured to extend into engagement with the notches 328 on the drive gear 330 . An opposite second end 344 of the second pawl 340 extends away from the third axle 346 .
[0035] The third axle 346 fits into a hole formed in the second pawl 340 . The third axle 346 rotatably supports the second pawl 340 . The third axle 346 also supports a bias spring 345 , which urges the first end 342 of the second pawl 340 into engagement with notches 328 on the drive gear 330 such that the first end 342 of the second pawl 340 provides a second ratchet for the drive wheel 330 . The second pawl 340 thus prevents the drive wheel 330 from “backing up” or reversing its rotation when the trigger 110 is released and moves away from the handle 108 .
[0036] The second pawl 340 is able to rotate through a small angle responsive to a compressive force applied to the second end 344 of the second pawl 342 . A compressive force, which can be provided by a user's finger or thumb, needs only be sufficient to overcome the bias applied to the second pawl 340 by the spring 345 .
[0037] The third axle 346 , which extends through the second pawl 340 , extends into and out of the plane of FIG. 3 . The opposite ends of the third axle are supported in the right and left sides 107 , 109 of the housing 106 .
[0038] FIG. 4 is a right-side view of the drive mechanism 104 . A bias spring 345 is wound around the third axle 346 . It provides a bias force that urges the first end 342 of the second pawl 340 into engagement with notches 328 in the drive wheel 330 .
[0039] As the second pawl is arranged and structured, the bias applied by the spring 345 maintains the first end 342 of the second pawl in contact with a notch 328 . The engagement of the second pawl to the toothed wheel 330 keeps the toothed wheel 330 from rotating backwardly, i.e., the second pawl limits the direction of rotation of the toothed wheel. As long as the first end 342 of the second pawl is engaged with a notch 328 , the toothed wheel 330 is unable to rotate against or counter to the direction that the toothed wheel is driven by the first pawl. In other words, the toothed wheel can only rotate in the “R” direction.
[0040] Both the first end 342 and the second end 344 of the second pawl 340 extend away from the third axle 346 but not necessarily in opposite directions. In a preferred embodiment as shown, the second end of the second pawl is curved such that the second end 344 of the second pawl is proximate to the second end 326 of the first pawl (not visible in FIG. 4 ) such that depressing or forcing the second end 344 of the second pawl 340 inwardly as shown causes the second end of the second pawl into engagement with the second end 326 of the first pawl.
[0041] Pushing the second end of the second pawl such that the second end of the second pawl also pushes the second end of the first pawl inwardly, i.e., toward the first axle, causes the first end of both pawls to disengage from the respective notches in the drive wheel. Stated another way, the first end of the second pawl and the first end of the first pawl are both disengaged from the toothed wheel 330 when a force is applied to the second end of the second pawl sufficient to overcome the bias applied to both pawls by their respective actuating bias springs.
[0042] Referring now to FIG. 5 , a toothed sprocket 360 is attached to and rotates with the toothed wheel 330 on the same first axle 306 . The second end 309 of first axle 306 is supported in the housing 106 by the second side 304 of the axle support 300 .
[0043] The sprocket 360 is formed to have sprocket teeth 362 , which are sized, shaped and arranged to engage or fit into the open or first side 402 of the U-shaped links 208 of the push chain 210 . The attachment of the toothed wheel 330 to the sprocket 360 means that rotation of the toothed wheel 330 will also rotate the sprocket 360 . As long as the first sides 402 of the push chain links 208 are engaged to the sprocket teeth 362 , rotation of the sprocket 360 will drive and retract the first end 214 of the push chain 210 into and out of the tube support 102 , pushing and pulling the piston 112 at the same time.
[0044] The links of the chain 210 are kept engaged to the sprocket and its teeth by two push chain retainers 404 , 406 . In a preferred embodiment and as shown in FIG. 5 , the push chain retainers 404 , 406 are columns or pins that extend outwardly from at least one of the two sides 107 , 109 of the housing 106 . Alternate embodiments include pads or tabs that extend over the push chain links just ahead of where the push chain links engage the sprocket teeth so that the chain links are able to travel past the retainers and engage the sprocket.
[0045] The push chain retainers 404 , 406 are located relative to the sprocket and sprocket teeth in order to keep portions of the push chain 400 that wrap around the sprocket 360 in place, i.e., keep the chain links engaged to the sprocket teeth. The bottom or second push chain retainer 406 also functions to limit the rotational travel of the actuating trigger 110 .
[0046] As best seen in FIG. 4 , portions of the push chain that extend outwardly or away from the sprocket, i.e., toward the first end of the tube support, are substantially straight. Those links, i.e., the ones beyond the push chain retainers, are considered herein to be “fully unfolded.” The fully unfolded links in the “top” portion of the chain, i.e., the portion of the chain that extends into the support tube 102 , are fully unfolded and able to support a compressive load, including the force applied to the first section of straight chain that extends from the top or first push chain retainer 404 forwardly to the second end of the push rod. Stated another way, the push chain retainers 404 , 406 are located and fixed at locations along the length of the chain where the straight sections, i.e. the chain section inside the tube support and inside the chain magazine begin to bend around the sprocket. The links that engage the sprocket thus form a third intermediate or curving section of push chain links. The third or intermediate curving section is considered herein to be the number of chain links that are engaged with teeth of the sprocket. By virtue of their engagement with the circular sprocket, the links forming the intermediate section cannot be straight and are, in fact, curved.
[0047] FIGS. 3 , 4 and 5 show a push chain guide 410 , best seen in FIG. 5 . It is preferably embodied as a thin, flat curved strip of metal having a radius of curvature substantially equal to the radius of curvature described by the sprocket and push chain links engaged therewith. The opposing first and second ends 412 , 414 of the push chain guide 410 are mounted to or attached to the two aforementioned push chain retainers 404 , 406 . The push chain guide 410 facilitates “threading” or feeding the push chain 210 and its links 208 into engagement with the sprocket teeth during initial assembly of the drive mechanism 104 . At assembly the second end 214 of the push chain 210 can be fed or inserted into the opening in the first end 218 of the support tube 102 and then “fed” into engagement with the sprocket teeth. The push chain guide 410 thus ensures that the open sides 402 of the push chain links 208 will engage teeth 362 on the sprocket 360 .
[0048] Referring to FIGS. 4 and 5 , actuating the second end 344 of the second pawl 340 , both pawls will disengage the toothed wheel, allowing the sprocket to rotate “backwardly” allowing the push chain 210 to be wrapped around the sprocket and have the second end 214 of the chain 210 pushed into the magazine 104 . When the entire length of the push chain 210 is installed, the piston rod is attached to the first end 212 of the push chain 210 .
[0049] For completeness, FIG. 6 shows a side view of the rodless dispenser drive mechanism 104 , push chain 210 and piston rod 224 but with the push chain 210 removed from the magazine to show that the back or second sides of the links are able to provide a substantially straight, flat or planar surface when the first sides 402 of links 208 are rotated away from each other. The push chain 210 is shown as it would rest in the magazine 114 , with several links 208 that are adjacent to each other, “fully unfolded.”
[0050] When the open, first sides 402 of two more links are rotated away from each other to be fully unfolded, those chain links form a substantially straight and substantially column-like, rod-like structure. Such chain links are able to provide a compressive force along a line formed by the links that are unfolded, i.e., urged to rotate in a direction opposite the direction that the chain links are able to rotate toward each other. When the links are unfolded, the open or “first” sides 402 of each chain link 208 face upwardly. The opposing second sides 403 , which are shown as edges, are depicted by straight line segments of each link 208 .
[0051] The links 208 that are shown wrapped part way around the sprocket 360 are partly folded toward each other. Stated another way, the links are able to rotate toward each other as they wrap part way around the sprocket.
[0052] The chain links 208 that are to the left of the lower push chain retainer 406 are fully unfolded relative to each other. Since the second side 403 of each link is planar, the second sides of the fully unfolded links that are adjacent to each other and to the left of the push chain retainer 406 provide an extended flat or planar surface 600 . The planar surface 600 formed by second sides 403 of two or more fully unfolded chain links 208 is able to freely slide over the push chain retainers 404 and 406 .
[0053] The piston rod 224 has a geometric center line 606 . The piston 112 itself also has a center line 610 . When the piston 112 is urged against an extrudable material by force 608 applied to the piston 112 by the piston rod 224 , or when the piston 112 is urged against another, different piston inside a tube of extrudable material not shown, an opposing force 612 is distributed across the face 614 of the piston 112 driven by the piston rod 224 . The opposing force 612 on the piston 112 effectively acts through the center line 610 of the piston 112 .
[0054] When the T-shaped piston rod 224 is properly attached to the bottom of the piston 112 , driving force 608 from the chain 210 is effectively transmitted into the connecting rod 224 through the geometric center line 606 of the piston rod 224 . The piston rod 224 is attached to the piston such that the force 608 applied to the piston 112 from the piston rod 224 will be offset from the center 610 of the piston 112 such that the force 608 from the piston rod 224 is applied to the piston 112 below the center line 610 of the piston 112 , as described in the aforementioned patent application Ser. No. 12/703,613, filed Feb. 10, 2010, and which is entitled “Piston and Piston Rod for a Rodless Dispenser, incorporated herein by reference. Since the opposing force from extrudable material 612 acts in an opposite direction, and at a location above the point of application of the force 608 driving the piston 224 into the extrudable material, the piston 112 will tend to rotate in the tube of extrudable material. The direction of rotation R′ (read as “r” prime) will be clockwise as the piston 112 is shown in FIG. 6 . A rotation of the piston 112 and piston rod 224 “into” the chain links will tend to urge the chain links 208 that extend forwardly from the top of the toothed drive wheel 330 to their fully unfolded position keeping them locked and able to support/provide the force 608 to the piston 112 . Stated another way, the chain links connected to the slightly rotated piston 112 and slightly rotated piston rod 224 will be locked into their fully unfolded position just by the exertion of a force 608 on the piston 112 by the chain 210 .
[0055] Replacing a tube of extrudable material is accomplished by the dual disengagement of the pawls, followed by or accompanied by retracting the chain 210 . The chain is retracted simply by grasping the retractor and sliding the retractor 220 outwardly toward the second end 204 of the tube support while the pawls are held disengaged from the drive wheel 330 . The dual disengagement of both pawls by the operation of a single actuator simplifies and facilitates the retraction of the piston 112 and push chain 210 into the magazine 114 and is an improvement over prior art.
[0056] The foregoing description is for illustration purposes only. The true scope of the invention is set forth in the claims. | A dispenser for viscous, extrudable materials uses a sprocket-driven push chain that is drawn from a chain magazine responsive to actuation of a user trigger. The sprocket for the chain is driven by a toothed wheel, which is driven by a first, ratcheting drive pawl, which is actuated by the trigger. A second ratcheting locking pawl prevents the toothed wheel and hence the chain sprocket from rotating backward when the trigger is released. A single “button” or actuator can be actuated by one hand of a user while the user's other hand grasps a chain retractor to pull an extended chain back to a starting position whereat the dispenser can be reloaded. | 1 |
CROSS REFERENCES TO RELATED APPLICATIONS
This application is a U.S. national stage application of international app. No. PCT/FI2004/000058, filed Feb. 5, 2004, the disclosure of which is incorporated by reference herein, and claims priority on Finnish App. No. 20030205, Filed Feb. 11, 2003.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The invention relates to an apparatus and a method in the treatment of the stock passed to a headbox of a paper machine or equivalent.
Centrifugal cleaning is needed in paper machines for separation of sand and contaminants. With today's technology, the cleaning efficiency of centrifugal cleaning deteriorates when the fiber consistency of the pulp suspension exceeds 1 percent. This limits the increasing of the feed consistency of the stock to be fed to the headbox. In practice, the slotted screen technique has made it unnecessary to use centrifugal cleaning for separating reject fibers, such as shives. A hydrocyclone plant is placed in the short circulation of the paper machine, where the flow rates are high, as high as 2000 l/s. To be operative, centrifugal cleaning requires a pressure difference of 120-150 kPa. In that connection, all (about 5) steps of the hydrocyclone plant require pumps, which represent as much as about 25 percent of the energy consumption of the short circulation. At a flow rate of 2000 l/s, the power consumption of centrifugal cleaning is about 1200 kW. A typical amount of fiber reject from centrifugal cleaning is about 0.1-0.2 percent of production. The loss of the filler pigments coming with coated broke is at its worst about 0.5 percent of machine production.
A filler recovery system is often incorporated in connection with the centrifugal cleaning of the short circulation. In addition to filler, the system must also process other rejects, such as fiber reject and sand, coming from the short circulation. In that case, the efficiency of the filler recovery system is not best possible.
Concepts are known in which the cleaning of the stock has been transferred from the short circulation to pulp lines. The consistency (about 3 percent) of the broke system is, however, not suitable for separation of sand with hydrocyclones.
When centrifugal cleaning is in the pulp line (e.g. chemical pulp, DIP or TMP), these pulps need not be cleaned again any more, but the debris, sand and non-disintegrating coating sheets of paper coming to the broke system via pulpers should be treated by means of hydrocyclones.
SUMMARY OF THE INVENTION
By placing a hydrocyclone plant in accordance with the invention in a broke system line in the short circulation, the problem is solved. The fiber consistency in the headbox can be increased, when needed, to a level of over 2 percent without the fiber consistency in the centrifugal cleaning exceeding the limit of 1 percent.
The size and the energy consumption of the hydrocyclone plant would be only about one third of the present size and energy consumption. The size is determined based on the maximal broke percentage.
At the same time, better selectivity is achieved in the filler recovery process.
In the invention, a hydrocyclone plant is placed in a stock line which is in the short circulation and uses broke, and it is connected with another stock line, so that the bulk of the stock flow (the purer stock) bypasses centrifugal cleaning.
The proposal reduces the energy consumption of centrifugal cleaning by about 65 percent, which means a saving of about 17 percent in the energy need of the short circulation. On a large machine the saved power is about 800 kW.
The amount of reject from centrifugal cleaning is reduced to a fraction, which means that the amount of reject from centrifugal cleaning would be in its entirety less than 0.05 percent of production. In practice, it could halve the amount of reject in the area of the paper mill, thus reducing the handling capacity associated with fiber recovery.
The investment in equipment is reduced by about 65 percent in centrifugal cleaning and by about 10 percent in respect of the short circulation. A hydrocyclone plant is a subprocess that takes up much space. By means of the arrangement in accordance with the invention, the paper machine hall is shortened by 3 m, with the result that the saving in building costs is considerable.
In accordance with the invention, a system is formed that includes at least two stock chests. The first stock chest comprises a stock composition M 1 containing pulp that requires centrifugal cleaning before it is passed to the headbox of the paper machine. The stock composition M 1 contains broke pulp passed from the paper machine and, in addition, it can contain pulp coming from fiber recovery and further mechanical pulp. The second stock chest comprises a stock composition M 2 containing pulp that has already undergone centrifugal cleaning, such as recycled fiber and/or chemical pulp and/or TMP. Thus, it does not contain any broke coming from the paper machine. In the arrangement in accordance with the invention, only the stock M 1 of the first stock chest is treated in the hydrocyclone plant and at least one accept is passed from it into connection with a second stock chest line and its stock M 2 . There can be more stock chests than two.
The apparatus in accordance with the invention thus includes a hydrocyclone plant that is much cheaper in capital expenditure and takes up less space than that of the prior art because its capacity need not be as high as that of the prior art arrangements in which all stock is passed through a hydrocyclone plant. In the arrangement in accordance with the invention, it is only the stock M 1 which has come as broke that is passed through the hydrocyclone plant in the short circulation of the headbox.
In the following, the invention will be described with reference to some advantageous embodiments of the invention shown in the figures of the appended drawings, but the invention is not meant to be exclusively limited to them.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a prior art apparatus for passing stock to a headbox of a paper machine.
FIG. 1B shows an arrangement in accordance with the invention.
FIG. 2A shows a first embodiment of the invention in which broke-containing stock is passed from a first stock chest to a hydrocyclone plant, and in which embodiment the stock is passed through a wire pit.
FIG. 2B shows a second embodiment of the invention.
FIG. 3 is an illustration of principle of the operation of a hydrocyclone plant.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1A shows a prior art stock system in which all stock M 1 +M 2 +M 3 is passed to a hydrocyclone plant 20 , which means that a high capacity is required from the hydrocyclone plant.
FIG. 1B shows an arrangement in accordance with the invention. A stock chest 10 a 1 contains stock, i.e. a pulp fraction M 1 , which contains broke passed from a paper machine and said pulp fraction M 1 is treated in a hydrocyclone plant 20 . The cleaned stock, its accepts are passed further into connection with stocks M 2 and M 3 that do not contain broke and further to a headbox 100 . The pulp fractions M 2 and M 3 that do not contain broke in stock chests 10 a 2 and 10 a 3 thus bypass the centrifugal cleaning 20 , and the accept of the stock M 1 from the hydrocyclone plant 20 is passed into connection with said stocks M 2 and M 3 . The hydrocyclone plant 20 is not required to have as high a capacity as that of the embodiment of FIG. 1A .
In the embodiment of FIG. 2A , stock M 1 , or a pulp fraction, of a first stock chest 10 a 1 also comprises a stock composition that requires centrifugal cleaning before it is passed to a headbox of a paper machine. The stock M 1 contains broke coming from the paper machine and, in addition, it may contain pulp coming from fiber recovery, and further mechanical pulp.
Stock M 2 of a second stock chest 10 a 2 comprises a stock composition that has already undergone centrifugal cleaning, such as recycled fiber and/or chemical pulp and/or TMP.
In the embodiment of FIG. 2A , the stock M 1 is passed from the stock chest 10 a 1 through a stock line a 1 to a lower part of a wire pit 11 . The line a 1 includes a pump P 1 . In the lower part of the wire pit, the stock M 1 is diluted with wire water obtained from a wire section of a paper machine (not shown) along a line d 1 to a consistency required by a hydrocyclone plant 20 . A line a 2 leads from the lower part of the wire pit 11 to the suction side of a pump P 2 and a line a 2 leads from the pressure side of the pump P 2 to a first centrifugal cleaning step 20 a 1 of the hydrocyclone plant 20 situated in the short circulation of the paper machine. In the figure, the centrifugal cleaning steps are designated with 20 a 1 , 20 a 2 , 20 a 3 . . . An accept line from the centrifugal cleaning step 20 a 1 of the hydrocyclone plant 20 ; a line a 3 is passed further to join a line b 1 of the stock M 2 of the second stock chest 10 a 2 via a mixing device 12 . The mixing device 12 is also supplied with wire water from the wire pit 11 along a line e 1 for diluting the stock M 2 to be fed to the headbox 100 to a suitable consistency.
From the upper part of the wire pit 11 there is further a line c 1 for dilution water, said line c 1 including a pump P 3 . The line c 1 leads further from the discharge side of the pump P 3 to a deaeration tank 13 a 1 . The dilution water passed through the deaeration tank 13 a 1 is conducted further after the deaeration treatment to a discharge line f 1 and further while pumped by a pump P 4 to a machine screen 14 a 1 , whose accepted fraction, i.e. accept, is passed to a dilution inlet header J 2 in the headbox 100 .
The stock chest 10 a 2 is provided with the line b 1 for the stock and further to the suction side of a pump P 5 . On the discharge side of the pump P 5 , the line b 1 is connected to the mixing device 12 , after which there is a pump P 6 in a line b 2 for pumping the combined stock further along the line b 2 to a deaeration tank 13 a 2 , from which a discharge line f 2 leads further to the suction side of a pump P 7 . On the discharge side of the pump P 7 , in the line f 2 there is a machine screen 14 a 2 , from which an accepted fraction, i.e. accept, is passed to a stock inlet header J 1 of the headbox 100 .
In the device arrangement in accordance with the invention, only the broke-containing stock M 1 passed from the stock chest 10 a 1 is treated in the hydrocyclone plant 20 . An accept line a 3 leads from said hydrocyclone plant further into connection with the stock line b 1 of the stock M 2 of the second stock chest 10 a 2 . Since the stock M 2 of the second stock chest 110 a 2 comprises stock that has already previously undergone centrifugal cleaning, said line can be connected directly to the headbox 100 of the paper machine, via its deaeration tank 13 a 2 and machine screen 14 a 2 .
In the embodiment of FIG. 2B , stock M 1 , i.e. a pulp fraction, of a first stock chest 10 a 1 also comprises a stock composition that requires centrifugal cleaning before it is passed to a headbox of a paper machine. The stock M 1 contains broke coming from the paper machine and it can additionally contain pulp coming from fiber recovery and further mechanical pulp.
Stock M 2 of a second stock chest 10 a 2 comprises pulp that has already undergone centrifugal cleaning, such as recycled fiber and/or chemical pulp and/or TMP.
Also in this embodiment of the invention, only the stock M 1 passed from the stock chest 10 a 1 is treated in a hydrocyclone plant 20 . In the embodiment of the figure, the stock is passed from the stock chest 10 a 1 through a line a 1 while pumped by a pump P 10 to a mixing device 120 , in which the stock is diluted to a centrifugal cleaning consistency with wire water obtained from a line f 4 , and the stock M 1 is passed further through a line a 2 to the suction side of a pump P 20 . The line a 2 on the pressure side of the pump P 20 is connected to the hydrocyclone plant 20 to form the feed of its first centrifugal cleaning step 20 a 1 .
In the embodiment of FIG. 2B , the hydrocyclone plant 20 situated in the short circulation of the paper machine includes centrifugal cleaning steps 20 a 1 , 20 a 2 and 20 a 3 . An accept line a 3 leads further from the first hydrocyclone, i.e. the centrifugal cleaning step 20 a 1 of the hydrocyclone plant 20 into connection with a stock line b 1 of a second stock chest 10 a 2 .
In the embodiment, wire water from the paper machine is passed to a wire pit 110 through a line d 1 , which wire pit 110 in this embodiment is formed by a planar wire pit structure, a so-called flume, which comprises a horizontal flow path for wire water. Said wire pit 110 removes effectively air in bubble form from the wire water, and pre-deaeration of the wire water is accomplished by means of said wire pit type. The wire water is passed from the wire pit 110 through a discharge line d 2 and a pump P 30 to a deaeration tank 13 a 3 , from which there is further a discharge line f 3 leading into connection with the line b, of the stock M 2 of the second stock chest 10 a 2 via a mixing device 12 . The line f 4 leads further from the discharge line f 3 of the deaeration tank 13 a 3 into connection with the line a 1 of the stock M 1 of the first stock chest 10 a 1 via the mixing device 120 . A branch line f 5 leads further from the line f 3 to a pump P 40 and further from the pressure side of the pump P 40 to a machine screen 14 a 3 , which conducts the wire water further as accept from the machine screen 14 a 3 to a dilution water inlet header J 2 of a headbox 100 .
The stock M 2 is passed from the stock chest 10 a 2 through a pump P 50 along the line b 1 to the mixing device 12 in order to be combined with the stock coming as accept along the line a 3 from the hydrocyclone plant 20 and with the dilution water coming along the line f 3 . After that the diluted stock is pumped by means of a headbox feed pump P 60 through a machine screen 14 a 4 to a stock inlet header J 1 of the headbox 100 .
As shown in FIG. 3 , the hydrocyclone plant 20 includes several centrifugal cleaning steps 20 a 1 , 20 a 2 , 20 a 3 , so that, as shown in the figure, accept from the first step 20 a 1 is passed through the line a 3 further into connection with the line b 1 of the stock M 2 of the second chest 10 a 2 . As shown in FIG. 3 , the stock is passed through the line a 1 as a feed to the first centrifugal cleaning step of the hydrocyclone plant 20 , i.e. to the hydrocyclone 20 a 1 . The stock flows along a spiral-shaped path inside the hydrocyclone 20 a 1 and heavier particles separate as reject from the bottom of the hydrocyclone and lighter particles rise as accept further through the line a 3 into the line b 1 of the stock M 2 passed from the second stock chest 10 a 2 . There can be several hydrocyclones 20 a 1 , 20 a 2 , 20 a 3 . . . and the reject from the first hydrocyclone 20 a 1 can be passed further to the second hydrocyclone 20 a 2 as its feed and the accept from it in one embodiment can be passed further to the line b, of the stock M 2 of the second stock chest 10 a 2 .
The figure shows a headbox 100 . The headbox 100 in accordance with the invention is advantageously a so-called dilution headbox, which means that the dilution water passed to the dilution water inlet header J 2 is passed further across the width of the headbox to different points of the stock passed from the stock inlet header J 1 In this way, dilution makes it possible to regulate the basis weight of the web across the width of the web. The dilution water passed from the dilution water inlet header J 2 is passed to ducts which are provided with dilution water valves, by means of which the supply of dilution water can be regulated as desired across the width of the headbox, thus enabling the basis weight of the web to be regulated to be even across the entire width of the web.
As shown in the figure, the hydrocyclone plant can also include several accept lines, the stock passed through them being conducted into connection with another stock or with stocks passed from other chests. In accordance with the invention, it is also possible to use several stock chests, but in the invention only that stock, such as the broke-containing stock M 1 , which shall be treated in the hydrocyclone plant is circulated through the hydrocyclone plant 20 . The pulp fraction M 2 which need not be cleaned with hydrocyclones is passed directly to deaeration and, after a machine screen, to the stock inlet header J 1 of the headbox 100 . The accept derived from the stock M 1 in the centrifugal cleaning 20 is conducted into connection with said stock.
When the stocks M 1 and M 2 of the chests 10 a 1 , 10 a 2 are referred to in this application, it is also possible to call them a pulp fraction M, and a pulp fraction M 2 . In this application, the paper machine is understood to mean paper, board and tissue machines.
The broke can be formed of paper broke, which can include trimmings or paper passed to a pulper in connection with web breaks.
The present application refers to lines by which are meant stock lines, pipes, ducts along which stock/wire water is passed. | An apparatus in the treatment of stock passed to a headbox of a paper machine or equivalent includes at least two stock chests ( 10 a 1 , 10 a 2 ). Stock (M 1 ) from a first stock chest ( 10 a 1 ) is passed along a line (a 1 , a 2 ) to a hydrococyclone plant ( 20 ) in the short circulation of the paper machine or equivalent. An accept line (a 3 ) of the hydrocyclone plant is connected with a stock line (b 1 ) of the stock (M 2 ) fed from a second stock chest ( 10 a 2 ), and a combined stock flow is passed along a line (b 2 ) to the headbox ( 100 ) of the paper machine or equivalent. A method in the treatment of the stock passed to a headbox of a paper machine or equivalent is disclosed. | 3 |
FIELD OF THE INVENTION
The present invention relates to a transcoder for a mobile communication system. More particularly, the present invention relates to a multi-channel transcoder rate adapter having an integrated echo cancellation function.
BACKGROUND INFORMATION
Mobile digital communication systems, particularly systems using the Group Special Mobile (GSM) standard, require various interfacing devices to connect a "far-end" mobile unit, for example a cellular mobile phone, to a "near-end" network, for example a land-based Public Switched Telephone Network (PSTN). A typical mobile system, as depicted in FIG. 1, includes a collection of mobile units 103 that communicate multiple channels of voice data via known radio carrier methods through an area 104 having a collection of base transceiver systems (BTS) 102 deployed at preselected geographic locations. The BTS's 102 are in turn connected via, for example, Abis lines 107 to a mobile switching center (MSC) 101 that coordinates the various signals being transmitted to and from the base stations. The MSC 101 is further connected to at least one echo-canceller 108 (explained further below) via at least one standard 64 Kbps PCM line 109. The echo-canceller 108 is then connected to the PSTN 105 via, for example, at least one standard 64 Kbps PCM trunk line 106.
In order to maximize the bandwidth available to the GSM network and to ensure the reliability of transmitted signals, data transmitted over the GSM network is encoded prior to radio transmission, and then decoded upon reception. This encoding/decoding process is accomplished through the use of transcoders located, for example, in the MSC 101 and the mobile unit 103. The functional architecture of a conventional GSM transcoder processing a single traffic channel is shown in FIG. 2. The transcoder 200 would be located, for example, at both the MSC 101 and each mobile unit 103 in order to provide encoding and decoding functions at both "ends" of the network. The transcoder 200 can be functionally divided into a transmit handler 201 (also known as a TxDtx handler) and a receive handler 202 (also known as an RxDtx handler).
Typically, the TxDtx handler 201 includes a voice activity detector (VAD) 203, a speech encoder 205, a comfort noise generator 207, and discontinuous transmission (DTX) control unit 209. In operation, digital data, for example digitized speech, is received by the speech encoder 205 as well as the VAD 203. The speech encoder 205 performs an encoding function on the speech data (for example, the encoding functions specified by GSM Specification 6.10) and sends the encoded data to the transmit DTX control unit 209. The VAD 203 concurrently analyzes the speech data and determines whether speech data is actually present or whether the data represents silence (such as a pause between speech). The VAD 203 then either clears or sets a VAD flag bit (VAD bit), depending on whether speech is present (clear) or not present (set). The VAD bit is sent to the Transmit DTX control unit 209.
If the VAD bit is not set, the transmit DTX control unit 209 causes the TxDtx handler 201 to output, for example, the encoded speech bits and a Speech Present flag bit (SP bit) at a set level, indicating the presence of speech in the data stream. If the VAD flag bit is set, however, the transmit DTX control unit 209 causes the TxDtx handler 201 to output a "comfort noise" signal (generated by the comfort noise generator 207). As is known in the art, comfort noise is a lower bandwidth representation of the silence between speech. The GSM Specification uses comfort noise to reduce the bandwidth needed to implement mobile communication. Thus, when no speech is present, the TxDtx handler 201 will output the comfort noise signal as well as the SP bit at a reset level to indicate the presence of comfort noise in the data path.
Also as shown in FIG. 2, the RxDtx handler 202 has an analogous structure to the TxDtx handler 201. Included in the RxDtx handler 202 are a speech decoder 204, a comfort noise decoder 206, and a receive DTX control unit 210. The input received by the receive DTX control unit 210 includes, for example, speech data bits, a silence descriptor flag bit (SID bit), and six time alignment bits (C-bits). If the SID bit is set (indicating comfort noise data in the data stream), the receive DTX control unit 210 diverts the speech data to the comfort noise decoder 206, which appropriately decodes the data. If the SID bit is not set (and the other transmitted flag bits are also not set), the speech data is sent to the speech decoder 204, where the data is decoded using a decoding function, for example the decoding function specified in GSM Specification 6.10.
The six C-bits (e.g., C6-C11) are used for "time-alignment." This adjustment is used to optimize the audio delay in the radio path. As described in the GSM specification, the bits C6-C11 force the decoder function to speed up or slow down in increments of 250 μs while the encoder function runs at a constant rate. The GSM specification also states that the encoding function and decoding function in the transcoder should not be synchronized. This allows for what is called "slew," where the long term rate of encoder and decoder messages is slightly different by the "slew" amount.
Due to the relatively slow data transmission rate used by GSM traffic channels (e.g., 16 Kbps) in comparison to the transmission rate of a PSTN trunk line (e.g., 64 Kbps), rate adaption is required to convert the GSM data received from or transmitted to the PSTN to the appropriate speed. Such known rate adapters have been implemented, for example, using digital signal processors (DSPs) to perform this rate conversion function. However, it has heretofore not been possible to handle more than one traffic channel in a single DSP rate adapter implementation together with transcoding functions due to, in part, the processing limitations of DSP technology. In a GSM mobile system where, for example, multiple channels are implemented, reduction of the number of DSPs needed to perform transcoding and rate adaption is advantageous to minimize system cost, physical size, and complexity.
An additional problem experienced in mobile telephony is signal echo, i.e. the reception of a previously transmitted signal due to reflection somewhere along the transmission path. Signal echo is not unique to mobile communications as any transmission network will experience echo where an impedance mismatch exists. However, mobile communication systems are highly susceptible to echo effects due to the signal delay inherent in the many signal processing functions performed along the transmission pathway. Echo effects are generally imperceptible to the human ear where the round trip transmission delay of the echo signal is less than 25 milliseconds. However, where the delay between the original transmission and the echo signal is of greater duration, the speaker/listener will be able to detect the echo, making conversation irritating. Mobile systems generally incur delays well over 25 milliseconds.
To combat echo, typical mobile telephone systems employ separate devices, known as echo-cancellers, added at the near-end (e.g. the PSTN end) of the mobile network. These separate devices, which can be implemented using DSPs, detect the presence of echo and filter the echo from received signals. A typical configuration for such an echo-canceller is depicted in the block diagram of FIG. 3. Although the operation of the echo-canceller shown in FIG. 3 is known in the art, the following summary explanation of the operation of a conventional echo-canceller is provided. A more detailed description of prior art echo-cancellers can be found, for example, in D. G. Messerschmitt, "Echo Cancellation in Speech and Data Transmission", IEEE Journal on Selected Topics in Communications, SAC-2, No.2, 283-303 (March 1984), which is expressly incorporated by reference.
The echo-canceller operates by first performing an adaptation process (also known as "training") to optimize the echo cancellation filters. As is illustrated by FIG. 3, Block 301 converts an 8 bit μ-law reference signal 310 (for example, the far-end speech data) to a 14 bit linear signal. Block 302 saves the most recent 128 reference samples in a FIFO, and outputs a far-end reference signal y(i). The transversal filter of block 303 perform a convolution of the far-end reference signal y(i) and the filter coefficients a(k) stored in block 305. Thus, block 303 creates signal est(i) which is the estimate of an echo signal s(i). For example, this convolution can be expressed as:
est(i)=summation for k=0. . . N-1 of {a(k)*y(i-k)}
The coefficients a(k) are adjusted, for example, using the LMS algorithm implemented in blocks 304 and 305 as follows:
a(k)=a(k)+2*G*u(i)*y(i-k),
where a(k) are the new updated coefficients of the transversal filter of block 303, u(i) is a filtered signal (described below), y(i-k) are the 128 most recent reference samples, and G is a gain value which controls the speed of the adaptation process.
In order to obtain optimal filter coefficients, a near-end speech detector 306 (NESP) is used to sense whether the near-end person is talking, and to halt the adaptation process when such speech is detected. A "hangover counter" (HCNTR) is set, for example, to the numeric value 600 whenever the following speech detector expression is true:
|s(i)|>0.5*max{|y(i)|,|y(i-1).vertline., . . . ,|y(i-N)|},
where
N is the number of transversal filter coefficients,
y(i) are the reference samples, and
s(i) is the output from block 308 which creates a 14 bit linear version of an 8 bit μ-law near-end signal (further described below).
HCNTR is decremented to zero, for example, on every 8 KHz sample and the adaptation of the a(k) coefficients resumes when HCNTR=0.
Block 308 receives the near-end signal from, for example, the PSTN, and converts this signal from an 8 bit μ-law signal to a 14 bit linear signal s(i). The error estimate signal est(i) is subtracted from the received signal s(i) to produce a filtered signal u(i). This filtered signal u(i) may still contain some residual echo even after filtration due to inaccuracies in the filter coefficients. Block 307 checks the signal u(i) for the presence of an unacceptable amount of residual echo, according to, for example, the following formulae:
Lu(i+l)=0.99*Lu(i)+0.01*|u(i)|,
Ly(i+l)=0.99*Ly(i)+0.01*|y(i)|,
where Lu(i) is a measure of the long-term energy in u(i),
Ly(i) is a measure of the energy in the signal y(i), and
u(i)=0 (suppress) whenever Ly(i)/Lu(i)>16 (16 corresponds to 24 db).
Where the residual echo is sizable (i.e. Ly(i)/Lu(i)≦16), the signal u(i) is not altered by block 307, and the completely filtered signal u(i) is set equal to u(i). However, when the echo-canceller output energy is, for example, 24 db below the reference energy, the signal u(i) is assumed to consist entirely of uncancelled echo with no local speech, so the signal u(i) is completely suppressed by block 307 (i.e. u(i)=0). Block 307 is also disabled whenever the NESP 306 detects near-end speech in order to allow this speech to pass through the echo-canceller without filtration.
The completely filtered signal u(i) is then converted from 14 bit linear format to 8 bit μ-law format in block 309, and finally transmitted over, for example, a 64 Kbps PCM line to an MSC.
As described above, conventional echo-cancellers compute the filter parameters by a training process that uses the existing far-end signal from the MSC as the reference signal 310. In a GSM network, however, silence is replaced by comfort noise. Add-on echo-cancellers cannot easily distinguish between comfort noise and actual speech. Thus, an add-on echo-canceller could falsely detect "doubletalk" which slows the training process, thereby reducing performance. It would be advantageous, therefore, to enhance the ability of the echo-canceller to detect such doubletalk.
An additional problem of using such add-on echo-cancellers is that they increase the cost and complexity of the mobile system. As mentioned previously, a single echo-canceller is required for each line connected to the PSTN. Thus, where multiple lines are used in the system, multiple echo-canceller units are required.
As mentioned above, mobile systems experience large amounts of signal delay along the transmission path from the mobile user to the PSTN. This delay is caused by the various signal processing functions performed on the voice signal along the communication path before it reaches its destination. One source of delay is the previously mentioned decoding process performed by transcoders. For example, the GSM Specification requires that a transmission consist of a 20 ms frame of 260 bits of user voice data, comprised of the data illustrated by the following table:
TABLE 1______________________________________Name Description No. Of Bits Bit No.______________________________________Sub Frame 1 Filter Parameters 36 b1-b36 LTP parameters 9 b37-b45 RPE Parameters 47 b46-b92Sub Frame 2 LTP Parameters 9 b93-b101 RPE Parameters 47 b102-b148Sub Frame 3 LTP Parameters 9 b149-b157 RPE Parameters 47 b158-b204Sub Frame 4 LTP Parameters 9 b205-b213 RPE Parameters 47 b214-b260 Total 260 bits 20 ms______________________________________
As shown in Table 1, each 260 bit frame can be divided into an initial sub-frame of 92 bits and three subsequent sub-frames of 56 bits each. Voice data frames are received by the transcoder unit, which then performs GSM decoding functions, for example those set forth in FIG. 4. The decoded data is output for further processing and ultimate transmission to either the PSTN or the mobile network.
FIG. 4 illustrates the functional elements of a conventional GSM speech decoder, such as speech decoder 204 shown in FIG. 2. The decoder 204 is run once for every 20 ms data frame. Short-term synthesis filter 401 uses bits b1-b36 and an internal signal dp(i) {i=1 . . . 160} to create signal sr(i) {i=1 . . . 160}. RPE grid decoder 402 uses bits b46-b92, b102-b148, b158-b204, and b214-b260 to create an error signal ep(i) {i=1 . . . 160}. Long term synthesis filter 403 is preset using bits b37-b45, b93-b101, b149-b157, b205-b213. The long term synthesis filter 403 then runs 160 times, each time using signal dp(i) {i=1 . . . 160} and creating signal dpp(i) {i=1 . . . 160}. Finally, post-processing block 404, which is a de-emphasis filter, uses signal sr(i) {i=1 . . . 160} and creates signal sro(i) {i=1 . . . 160}. The 160 bits sro(1) to sro(160) are the decoded voice data bits. Blocks 401, 402, 403 and 404, which are well known in the art, are more fully described in GSM Specification 6.10.
As described above, known transcoders utilize decoding units that must wait for the entire 20 ms frame of voice data to be received and decoded by the transcoder prior to beginning the transmission process. It is advantageous, however, to reduce this delay as much as possible in order to reduce echo effects which can degrade the quality of the communication services provided.
SUMMARY OF THE INVENTION
An object of the present invention is to implement a multi-channel transcoder rate adapter in a single DSP. The present invention provides a DSP system having multiple input and output buffers for storing multiple channel audio data. The DSP performs rate adaption through an interrupt-driven routine to place the appropriate channel data onto both the near-end and far-end transmission lines at the appropriate data rate. With the implementation of rate adaption, the DSP also has further processing power available to perform encoding and decoding of the incoming audio data.
A further object of the present invention is to enhance the echo-cancellation capability of a GSM system and to reduce the cost of implementing echo-cancellation in a GSM system. The present invention employs an echo-canceller that uses the already robust voice activity detection bits produced by the transcoder to perform a more accurate filtration of echoed signals. The combination transcoder/echo-canceller can implemented, for example, in a single DSP, which reduces the physical size and cost of the system, particularly where multiple lines are used.
A further object of the present invention is to reduce the delay caused by the GSM decoding process. The method of the present invention decodes a subframe of encoded audio data and places the resulting decoded bits in a transmit queue for transmission over the network. While the transmission of the resulting decoded bits is taking place, the next subframe of audio data is decoded. By initiating transmission of decoded data bits immediately, and not waiting until all the audio data bits have been received and decoded, significant reduction in the delay associated with the decoding process is achieved.
A further object of the present invention is a multi-channel transcoder unit having transcoding, rate adaption, and echo-cancellation functions, and using an improved decoding process, implemented in a single DSP. By scheduling the occurrence of system events into time windows according to the time allowed under the GSM specification, multi-channel operation can be achieved without time delay and within the bandwidth limitations of present DSPs. Additional benefits of reduced system size and cost are also realized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of an exemplary cellular mobile telephone systems.
FIG. 2 shows a block diagram of an exemplary conventional GSM transcoder unit.
FIG. 3 shows a block diagram of an exemplary conventional add-on echo-canceller.
FIG. 4 shows a functional block diagram of conventional GSM decoding functions according to the GSM Specification.
FIG. 5 shows a block diagram of a hardware implementation of a first exemplary embodiment of a transcoder rate adapter according to the present invention.
FIG. 6 shows a functional block diagram of multi-channel operation of the transcoder rate adapter according to the present invention.
FIG. 7 shows a flow chart of the multi-channel operation of the transcoder rate adapter according to the present invention.
FIG. 8 shows a functional block diagram of a second exemplary embodiment of a transcoder with an integral echo-canceller according to the present invention.
FIG. 9 shows a functional block diagram of the echo cancellation functions of the transcoder with an integral echo-canceller according to the present invention.
FIG. 10 shows a functional block diagram of a comfort noise booster according to the present invention.
FIG. 11 shows a third exemplary embodiment of a multi-channel transcoder with an integral echo-canceller according to the present invention.
FIG. 12 shows a functional block diagram of the decoding unit of a fourth exemplary embodiment of the present invention.
FIG. 13a shows a flow chart of the decoding process for a first subdecoder according to the present invention.
FIG. 13b shows a flow chart of the decoding process for a second subdecoder according to the present invention.
FIG. 13c shows a flow chart of the decoding process for a third subdecoder according to the present invention.
FIG. 13d shows a flow chart of the decoding process for a fourth subdecoder according to the present invention.
FIG. 14 shows a schedule of single channel software functions according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A block diagram of the hardware configuration for a first exemplary embodiment of a transcoder rate adapter unit (TRAU) according to the present invention is shown in FIG. 5. The TRAU 500 is located, for example, at the MSC of the GSM network, such that the encoding, decoding, and rate adaption functions required at the MSC can be realized.
TRAU 500 includes a single DSP chip 501. The DSP 501 is connected to a 16 Kbps transmission line 502 capable of carrying, for example, 4 traffic channels. The DSP 501 is connected to a 64 Kbps transmission line 503 also capable of carrying, for example, 4 traffic channels. The 16 Kbps transmission line can be, for example, a 16 Kbps Abis line, and the 64 Kbps transmission line can be, for example, a 64 Kbps PCM line. These lines are functionally bidirectional, each transmission line is connected to both an input and output of the DSP 501. The DSP 501 is further connected via an address bus 504, a data bus 505, and a control bus 506 to at least one RAM 507 and at least one a ROM 508 chip, in a conventional manner. The DSP used in this exemplary embodiment can be, for example, an Analog Devices 2106x DSP chip.
FIG. 6 is a diagrammatic representation of the multi-channel operation of the TRAU 500 according to the present invention. As previously mentioned, the DSP 501 is connected to the 16 Kbps transmission line 502 and the 64 Kbps transmission line 503. Within the TRAU 500 are buffers for storing the voice data received by the TRAU 500 from these lines: a bank of 4 GSM-receive buffers 601-604; and a bank of 4 PSTN-receive buffers 613-616. Also within the TRAU 500 are buffers for storing voice data that has been processed by the TRAU functional units and is ready for transmission to the PSTN or GSM network: a bank of 4 GSM-transmit buffers 609-612; and a bank of 4 PSTN-transmit buffers 605-608. Each buffer in each bank of four buffers corresponds to an individual traffic channel. Thus, in this exemplary embodiment of the present invention, the TRAU 500 is capable of processing four traffic channels.
FIG. 7 describes the method steps performed by the DSP 501 in implementing a multi-channel TRAU architecture according to the present invention. The DSP 501 generates an interrupt 701 every, for example, 125 microseconds, to force the initiation of a reception/transmission routine. As a first step 702 of a far-end receive routine, the DSP 501 sequentially samples the 16 Kbps line 502, reading two bits corresponding to one of four possible GSM traffic channels: TCH1; TCH2; TCH3; or TCH4. In step 703, these bits are stored in an appropriate GSM-receive buffer 601-604 corresponding to the sampled traffic channel. Once these two bits have been received in the current channel buffer, step 704 switches the designated GSM-receive buffer to the next channel buffer in preparation for the next execution of the far-end receive routine. The data bits are stored sequentially in the GSM-receive buffers 601-604, so that the information that is read from these buffers by other functional units within the TRAU 500 (such as, for example an RxDtx handler) will coherently represent the transmitted voice data.
A far-end transmit routine is also executed to transmit multi-channel voice data to the far-end network. In step 721, the DSP 501 reads two bits from the appropriate GSM-transmit buffer. In step 722, the DSP 501 places the bits on the 16 Kbps transmission line 502 in a conventional manner. In step 723, the DSP 501 switches to the next channel buffer in preparation for the next execution of the far-end transmit routine.
Routines for transmission to and receipt from the near-end network are also performed, as shown by steps 741-763. For example, in step 761 of the near-end transmit operation, the DSP 501 reads 8 bits of data from one of the PSTN-transmit buffers 605-608 containing voice data corresponding to one of four traffic channels: PCM1; PCM2; PCM3; or PCM4. In step 762, the DSP 501 places this data sequentially on the 64 Kbps transmission line 503 in a conventional manner. In step 763 the DSP 501 switches to a new buffer corresponding to another traffic channel, in preparation for the next near-end transmission sequence. In step 741 of the near-end receive operation, the DSP 501 samples the 64 Kbps transmission line 503 for 8 bits over 125 microseconds. In step 742, the DSP 501 sequentially places the sampled bits in the PSTN-receive buffer corresponding to one of the four traffic channels. In step 743, the DSP 501 switches to another buffer in preparation for the next near-end receive cycle.
Thus, as previously described, the TRAU 500 of first exemplary embodiment of the present invention implements four GSM traffic channels in a single DSP. The resulting TRAU 500 is a single DSP implementation of a complete transcoder and rate adapter, capable of processing multiple traffic channels. Consequently, system size, cost and complexity are significantly reduced.
The four-channel embodiment described above can be achieved while still leaving additional processor bandwidth available for further functional implementations in the DSP. This remaining DSP bandwidth can be utilized, for example, to implement the additional functions needed for echo-cancellation at the MSC end of the network (as is more fully described below).
A block diagram of the functional elements of a second exemplary embodiment of the present invention is shown in FIG. 8. This exemplary embodiment implements a transcoder unit having an integrated echo-canceller. These elements may be implemented using conventional hardware components, including DSPs arranged in a conventional manner. The transcoder/echo-canceller unit 800 is located, for example, at the MSC of the GSM network, such that the encoding, decoding, and echo-cancellation functions required by the MSC may be realized.
A GSM-in buffer 801 is connected to the input from the far-end network and can also connect to a comfort noise booster 811, as shown. An RxDtx handler 202 (as previously described in FIG. 2) has an input connected to the comfort noise booster 811 and an output connected to a receive-in buffer 801. A GSM-out buffer 802 has an output connected to the far-end network and has an input connected to an output of a TxDtx handler 201 (as previously described in FIG. 2). Both the GSM-in and GSM-out buffers 801, 802 are further connected to a speech detector 810.
The speech detector 810 has an output connected to an echo-canceller 809. The echo-canceller 809 has an input connected to the receive-in buffer 803 and an output connected to the TxDtx handler 201 via a send-out buffer 804. The echo-canceller 809 also has an output connected to a receive-out buffer 805 and an input connected to a send-in buffer 806. The receive-out and send-in buffers 805, 806 are connected to the near-end network.
In the receive operation of the transcoder/echo-canceller unit 800 according to the present invention, voice data is received by the GSM-in buffer 801 from the far-end network. The voice data received by the GSM-in buffer includes, for example: a plurality of information bits (representing speech bits); the SID bits; the BFI bit; the TAF bit; and the C-bits. After a comfort noise boosting function is performed by the comfort noise booster 811 (described below), the RxDtx handler 202 reads the voice data from the GSM-in buffer 801, performs a decoding function on this data (as previously described) and places the decoded voice data bits in the receive-in buffer 803. The echo-canceller 809 retrieves the decoded voice data bits from the receive-in buffer 803, performs various echo cancellation operations (as described below), and transmits these bits to the receive-out buffer 805. From there, the decoded voice data bits enter the near-end network for transmission to the land-based listener in a conventional manner.
In the transmit operation of the transcoder/echo-canceller unit 800, near-end voice data is received by and stored in the send-in buffer 806. The echo-canceller 809 retrieves this data from the send-in buffer 806 and performs echo-cancellation functions to remove possible echo from the voice data (as described below). The filtered voice data is subsequently placed in the send-out buffer 804, where it can be retrieved by the TxDtx handler 201. The TxDtx handler 201 performs the encoding and voice detection functions on the voice data.
Specifically, if the voice activity detector 203 (see FIG. 2) located in the TxDtx handler 201 determines that the filtered voice data does not contain speech, the SP bit is cleared to indicate the absence of speech, and the comfort noise generator 207 (see FIG. 2) is directed to replace the filtered voice data with comfort noise data. However, if the voice activity detector 203 determines that speech is present in the filtered voice data, the encoder 205 performs an encoding function on the filtered voice data and sets the SP bit. The resulting voice data bits and SP bit are sent to the GSM-out buffer 802, where they will enter the far-end network for transmission to the mobile user in a conventional manner.
The integrated echo-canceller feature of the transcoder/echo-canceller unit 800 according to the present invention shown in FIGS. 8 and 9 implements integrated echo-cancellation through the use of echo-canceller unit 809, speech detector unit 810 and comfort noise booster 811. As shown by FIG. 9, the echo-canceller 809 employs many of the same functional units as the conventional echo-canceller illustrated in FIG. 3. Since the GSM network uses linear audio samples, though, the μ-law to linear converter block 301 and the linear to μ-law converter block 309 are not needed. An additional linear to μ-law converter block 901, however, is needed at the near-end output of the echo-canceller in order to prepare the signal for transmission over, for example, the PSTN. Furthermore, echo-canceller 809 of the present invention uses the signals INHIBIT and HCNTR to achieve a better training than available with conventional echo-cancellers, as will be more fully described below.
As previously described, echo cancellation is achieved through two phases of operation: a training phase; and a filtering phase. The echo-canceller unit 809 determines the appropriate phase of operation based on the level of a signal HCNTR, which is derived in the NESP 306 (FIGS. 3, 9), and a signal INHIBIT which is derived in the speech detector 810 illustrated in FIG. 8. As is already known in the art, the NESP 306 detects the presence of speech-in the near-end data and halts the training process whenever near-end speech is present. The signal HCNTR is produced by the NESP 306 to indicate a halt condition. The present invention also uses the speech detector 810 to detect speech in the data path. The speech detector 810 accesses the SID bits and the SP bit from the GSM-in buffer 801 and the GSM-out buffer 802, respectively, to determine whether speech is present from either the near-end or far-end. When the far-end is quiet (and therefore comfort noise is being produced) and the near-end is talking, the INHIBIT signal is set, signifying that the training phase must be momentarily halted. This can be expressed as, for example:
if (far end is quiet and near end is talking) then don't train.
Or, for example, as a "C" language expression:
if ((SID==1 || SID==2) && SP==1) {INHIBIT=1;} else {INHIBIT=0;}
When INHIBIT is set, this halts the update of the transversal filter coefficients. Thus, the use of the INHIBIT signal in addition to the HCNTR signal improves the training phase by preventing false training when local speech is indeed present. The robust SP and SID bits from the GSM data stream add reliability to the echo-canceller speech detection operation.
As previously described, in the training phase of operation, the echo-canceller 809 trains on the signal being sent by the mobile user. Training provides the parameters for the echo cancellation filters 303 used to filter incoming voice data. When far-end speech is not present, comfort noise is automatically sent from the mobile unit (per the GSM specification). The integrated echo-canceller of the present invention uses this comfort noise signal for training. Since the comfort noise is conditioned to the individual channel, it is not offensive to the near-end listener.
The comfort noise booster 811 is used to amplify the comfort noise signal when needed for training operations. The comfort noise booster 811 is shown in more detail in FIG. 10. Demultiplexer 1001 extracts bits from the 260 bit voice frame corresponding to the amplitude parameters for each subframe (denoted Xmax1-Xmax4). It is then determined in the amplification block 1003 whether a boost is required, according to, for example, the following expression:
if training phase is active and the far-end is sending comfort noise, then amplification is on, else amplification is off.
Or, for example, as a corresponding "C" language expression:
if (HCNTR==0 && SID|=0) {boost=1;} else {boost=0;}.
If it is determined that amplification is needed, each Xmax parameter is set to, for example, a value of 16. Multiplexer 1002 then reinserts the Xmax parameters into the correct locations in the 260 bit data frame.
In the filtering phase of operation, the echo canceller 809 receives the voice data from the near-end network (as stored in the send-in buffer 806) and filters that voice data according to the parameters of the echo cancellation filters 303 set during training. The filtered voice data is subsequently stored in the send-out buffer 804, for later retrieval by the TxDtx handler 201.
As a result of the combination of transcoder and echo-cancellation functions, the transcoder/echo-canceller unit 800 of the present invention exploits the robust GSM speech detection functional units to derive a better training function. The transcoder/echo-canceller unit 800 of the present invention also exploits the comfort noise used by the GSM network to derive a better training.
FIG. 11 shows, as a third exemplary embodiment of the present invention, a multi-channel transcoder/rate adapter/echo-canceller (TRAU/EC) 850. The TRAU/EC 850 implements a multi-channel GSM architecture (for example a four channel system) by using multiple transcoder/echo-cancellers 800 (as shown by FIG. 8) in conjunction with the rate-adaption architecture of TRAU 500 (as shown by FIG. 6). Furthermore, the TRAU/EC 850 of this third exemplary embodiment can be implemented in a single DSP chip (for example, in the hardware configuration shown in FIG. 5), using the excess bandwidth remaining after the implementation of rate adaption and transcoding functions.
As shown functionally by FIG. 11, each of the functional units of the transcoder/echo-canceller 800 (shown in FIG. 8) would be implemented four times within the DSP 501 in forming TRAU/EC 850. Rate adaption is achieved using a rate adaption control block 1101 in conjunction with the buffering scheme of FIGS. 6 and 8. Specifically, the GSM-in and GSM-out buffers 801, 802 for the multi-channel TRAU/EC 850 would correspond to the individual GSM-receive and GSM-transmit buffers 601-604, 609-612 for each channel (as shown by FIG. 6). Accordingly, the receive-out and send-in buffers 805, 806 for the multi-channel TRAU/EC 850 would correspond to the individual PSTN-transmit and PSTN-receive buffers 605-608, 613-616 for each channel. The receive-in and send-out buffers 803, 804 are also implemented as four individual buffers corresponding to each traffic channel being serviced. The rate adaption control block 1101 performs, for example, the functions described in the flow chart in FIG. 7. Thus the multi-channel TRAU/EC 850 can provide full transcoding, rate adaption, and optimized echo-cancellation functions over multiple traffic channels, all implemented in a single DSP system.
A fourth exemplary embodiment of the present invention is an optimized decoding method implemented in a decoding unit for use in an RxDtx handler (such as RxDtx Handler 202 (see FIG. 2)). The decoding method of this fourth exemplary embodiment of the present invention uses, for example, four subdecoding units to process each 20 ms frame of data to be decoded. As will be further explained below, each subdecoder operates on a different subframe of speech data, producing 40 samples of decoded voice data, which can be sent to an appropriate buffer for immediate transmission without the need to wait for the completion of the decoding being performed by other subdecoders. Since the method of the present invention relates to decoding of GSM data, it can be implemented in the transcoder at, for example, both the MSC and mobile unit ends of the network.
As shown by FIG. 12, a decoder unit 1201 is implemented within a transcoder 1200 using four subdecoder units: Subdecoder0 1202; Subdecoder1 1203; Subdecoder2 1204; and Subdecoder3 1205. The decoder unit 1201 receives encoded digital voice data, for example a 260-bit GSM voice data frame, from a data source (not shown). Since the decoder unit 1201 can be used in both a near-end and the far-end transcoder, the data source could be either a near-end or a far-end user. The data source can be interfaced by using, for example, a receive buffer 1206. The receive buffer 1206 is connected to the decoder unit 1201, so that the subdecoders 1202-1205 can read the voice data bits from the receive buffer 1206. The output of the decoder unit 1201 is connected to, for example, a transmit buffer 1207, which can act as an interface between the decoder unit 1201 and the subsequent functional units of the transcoder 1200 (e.g. a DTX controller (see FIG. 2)) or the destination network.
FIGS. 13a-13d show the operation of the decoding process according to the present invention. As shown by step 1301 in FIG. 13a, Subdecoder0 1202 reads the first 92 bits of the digital voice data frame from the receive buffer 1206. In step 1302, these bits are split into three groups: Filter Initialization bits; LTP bits for subframe 1; and RPE bits for subframe 1 (described in Table 1). In step 1303, the bits b1-b36 are input into the short term synthesis filter 401 for use over the entire 20 ms frame by all four subdecoders. In step 1304, the bits b37-b45 are sent to the long term synthesis filter 403, and in step 1305 the bits b46-b92 are sent to the RPE grid decoder 402. In step 1306, the GSM decoding operations--short term synthesis filtering, long term synthesis filtering, RPE grid decoding and positioning, and post-processing--are then performed on the subframe, according to the same methods as described in FIG. 4. The product of the decoding process of subdecoder0 1202 are the bits sro(i) {i=1 . . . 40}, which represent the first 40 bits of decoded voice data. In step 1307, these 40 bits are stored in transmit buffer 1207. Transmission of these 40 bits over the destination network may now begin (step 1308).
Once subdecoder0 1202 has sent the first 40 decoded bits to the transmit buffer 1207, subdecoder1 1203 begins decoding the next 56 bits of the data frame. Accordingly, in step 1311, bits b93-b148 are read from the receive buffer 1206, and in step 1312, split into LTP parameter bits and RPE parameter bits. Since the Filter Initialization bits have already been set (during the execution of subdecoder0 1202), these bits need not be altered. The long term synthesis filter 403 is next loaded with the LTP parameter bits (step 1313) and the RPE grid decoder 402 is loaded with the RPE parameter bits (step 1314). In step 1315, the decoding functions 401-404 are run using the bits b93-b148, producing the 40 sampled bits sro(i) {i=41 . . . 80}. In step 1316, these 40 decoded samples are then sent to the transmit buffer 1207 in the same fashion as for subdecoder0 1202, where, in step 1317, transmission of these bits may begin.
Subdecoder2 1204 and subdecoder3 1205 are similar to subdecoder1 1203, except that in subdecoder2, the bits b149-b204 are retrieved from the receive buffer 1206 and operated on in a manner similar to subdecoder1, and in subdecoder3 the bits b205-260 are retrieved from the receive buffer 1206 and operated on in a manner similar to subdecoder1. The 40 decoded samples resulting from each of these subdecoders are likewise sent to the transmit buffer 1207.
As indicated above, once a subdecoder has completed processing a subframe of GSM speech data by sending 40 decoded samples to the transmit buffer 1207, the transcoder 1200 can then, in steps 1308, 1317, 1327, and 1337, begin transmission of the received voice data bits from the transmit buffer 1207 concurrent with the decoding of the next subframe of voice data. By performing transmission prior to reception and decoding of the entire digital voice data frame, the delay inherent in the decoding process can be significantly reduced.
For example, the delay caused by the decoding process where the entire digital voice data frame is received prior to beginning transmission is, at a minimum, 20 ms (the length of time needed for complete reception). However, the delay caused by the decoding process according to the present invention is, for example, 92 bits/260 bits*20 ms=7 ms. This delay reduction helps reduce echo effects, and improves the overall characteristics of the mobile network.
A fifth exemplary embodiment of the present invention is a multi-channel TRAU/EC that uses the optimized decoding method previously described. This fifth exemplary embodiment of the present invention can be implemented, for example, in a four channel system, such as is shown by FIG. 11. The speech decoder 204 used by the RxDtx handler 202 is replaced by the decoder unit 1201.
This fifth exemplary embodiment can be implemented in a single DSP (according to the hardware architecture of FIG. 5). However, in order to run four completely independent (and therefore asynchronous) traffic channels in a single DSP multi-channel TRAU/EC, a scheduling of the functions to be performed by the DSP is required so that delay and/or data loss does not occur. For example, for each channel, the encoding, echo-cancellation, and decoding functions (including the running of the four subdecoders) must be performed within a 20 ms window to keep pace with the GSM data stream.
FIG. 14 shows functional diagram of an exemplary schedule for one of the four channels. While only a single channel schedule is illustrated, the schedule shown is otherwise similar for all other channels, as will be explained below.
As previously stated, every 20 ms the functions of the encoder, echo-canceller, subdecoder0, subdecoder1, subdecoder2, and subdecoder3 must be performed. Each of these functions requires a maximum amount of time to run. For example, in an Analog Devices 21062 DSP at 40 MHz, the encoder was measured to take 1.0 ms, a 32 taps echo-canceller was measured to take 1.0 ms, and each subdecoder required 0.2 ms. To accommodate these tolerances, the schedule is broken into four, 5 ms windows: T1; T2; T3; and T4. The functions to be executed by the DSP (also called "jobs") are scheduled so that a single channel uses no more than 1.2 ms of processing. As a result, functions can be performed on all four channels in each 5 ms window, since 1.2 ms×4=4.8 ms. The remaining time in each time window can be used for other functions, such as diagnostics.
For example, as shown in FIG. 14, in time window T1, an echo-canceller job and a subdecoder0 job can both be run for a single traffic channel (1.0 ms+0.2 ms=1.2 ms). In time window T2, an encoding job and a subdecoder1 job can both be run for a single traffic channel (1.0 ms+0.2 ms=1.2 ms). In time window T3, subdecoder2 can be run, and in time window T4, subdecoder3 can be run. Thus, all functions required to be executed for the traffic channel can be run within the 20 ms time frame, leaving ample time to execute similar operations for the other three traffic channels.
The exemplary schedule of the fifth exemplary embodiment also accounts for time alignment. As previously described, the C-bits in the decoder stream tell the decoder to speed up or slow down, creating a slew effect. Slewing is accommodated by the dashed boxes in the FIG. 14. If this process is needed, it is only allowed to run in time windows T3 or T4, since these time windows are underutilized. Note that, even with additional processing due to slew, the totals for each time slot never exceed 4.8 ms. Thus all four-channels can run asynchronously and maintain data integrity. | A multi-channel transcoder with rate adapter converts the data rate of GSM and PSTN network data in a multi-channel network. A transcoder having echo-cancellation features uses the robust voice activity detection functions of the GSM transcoder functions to enhance the accuracy of echo-cancellation of near-end signals. A method for decoding a GSM signal in which the transmission of the audio data over the network is commenced prior to the completing of the decoding process. A transcoder unit having rate adaption and echo-cancellation with improved decoding is implemented in a single DSP and processes multiple traffic channels simultaneously. | 8 |
FIELD OF THE INVENTION
The present invention pertains to medical instruments, more particularly to tools in aid of safe handling, storage and disposal of surgical needles in a manner to minimize accidental needle puncture.
BACKGROUND OF THE INVENTION
As any user of surgical needles will readily attest, their handling has always entailed the risk of inadvertent needle punctures, particularly in the area of the hands. Rare, if ever, would be an instance of where even an occasional, much less frequent, user of surgical needles has not experienced repeated accidental needle punctures.
In cases where the inadvertent puncture is occasioned by a needle of assured sterility, no particular hazard of any significant or seriously threatening consequence is presented. Where, however, a needle is being used to inject or extract fluids into or from a body of unknown and possibly infectious germ state, the risk of needle puncture to the user becomes a matter of grave concern due to fact that such user could become seriously, if not fatally, infected.
Consider the practice of dentistry, where a practitioner would typically come in contact with a number of patients of casual acquaintance on a given day. In many instances, each patient will receive one or more injections of an anesthetic, or the like, depending on the dental procedure on hand. After each injection, good practice demands that the needle be recapped, either for re-use on the same patient, or preparatory to its discard. Heretofore, an inordinate risk of needle puncture has attended each needle recapping procedure, a procedure carried out so often and so routinely as to assure an untold number of instances of inadvertent needle puncture.
The long felt concern over accidental needle punctures by the users of surgical needles for fluid injections and extractions has become magnified due to the increasing prevalence of Acquired Immune Deficiency Syndrome (AIDS). Of course, for many years, there have been other serious diseases known to be transmitted by inadvertent punctures with infected needles, notably hepatitis. Now, with the lurking AIDS virus, practitioners have come to universally feel that even one accidental needle puncture is, emphatically, one too many. There is, accordingly, a keenly felt need for some expedient means towards minimizing the risk of such punctures.
SUMMARY AND OBJECTS OF THE INVENTION
The present invention is embodied in a surgical needle capping device designed to minimize the user's risk of inadvertent needle punctures in the course of handling such needles and more particularly to facilitate the safe capping/recapping of such needles for momentarily laying aside and/or ultimate discard. The device is of simple construction and economical manufacture, and is exemplified in both throw-away and reusable versions, the latter featuring a needle ejecting mechanism.
The subject device is sized for easy hand holding in an operative attitude and essentially comprises a conically-shaped needle entry section tapering to a tubular section and a socket of particular configuration formed within such tubular section at its juncture with such conical section. The socket is configured to receive and grip the hub of a conventional surgical needle and hub assembly against rotational movement to permit threaded engagement/disengagement of the assembly from a conventional surgical syringe. The conical needle entry section is designed to provide an optimum target to intercept and guide a needle point, as it is thrusted toward and into such section, to a safe and secure seating of the needle assembly hub portion within the mating socket while greatly decreasing the risk a chanced needle puncture of the user.
It therefore becomes an object of the invention herein described to provide a capping device for the safe and sure capping/recapping of surgical needles to thereby minimize disease transmission via accidental needle punctures.
Another object of the present invention resides in the provision of a hand-sized surgical needle capping device embodying a simplicity of design of easy and safe use and amenable to economical and precise manufacture in large quantities.
A further object of this invention is a surgical needle capping device of the above referenced character and having provision for the ready ejection of a needle assembly housed therewithin, whereby the capping device may be sterilized for re-use.
Yet another object of the present invention is a surgical needle capping device as above characterized wherein provision is made to accommodate needle assemblies of varying length.
Another object of this invention is to provide a surgical needle capping device as above characterized having an enhanced needle target area and which resists rolling when laid aside.
Other objects and advantages of the present invention will become apparent and will obviously follow a perusal of the following description and the accompanying drawings, which are merely illustrative and not limiting of such invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 pictorially illustrates heretofore conventional practice in capping/recapping surgical needles depicting the attendant liability of inadvertent needle punctures.
FIG. 2 pictorially illustrates the practice of capping surgical needles utilizing an embodiment of the needle capping device of the present invention.
FIG. 3 is a longitudinal perspective view depicting the entry of a conventional surgical needle assembly into an embodiment of the needle capping device of the present invention.
FIG. 4 is an axial perspective view of the needle capping device as viewed from its tubular end.
FIG. 5 is a view similar to that of FIG. 4, but from the opposite, conical end of the device.
FIG. 6 is a longitudinal perspective view of a needle ejecting version of the capping device depicting a conventional needle and hub assembly seated within such device and the needle ejecting plunger in its biased, needle-receiving position.
FIG. 7 is a view similar to that of FIG. 6, but depicting the interrelationship between the needle ejecting plunger in its depressed, needle-ejecting position and the disengagement of the hub member of a conventional needle assembly from the capping device.
DETAILED DESCRIPTION OF THE INVENTION
With further and particular reference to the drawings, FIG. 1 illustrates conventional surgical needle capping procedure and offers a depiction of the all too easily encountered hazard of needle puncture in performing the capping procedure. A conventional syringe 10 for surgical needles would typically comprise a syringe body or barrel 12 having a longitudinal opening 14 to facilitate the insertion of a vial or carpule 16 containing a chosen medication or other fluid. A syringe plunger 18 is mounted at one end of the barrel to be reciprocated longitudinally along such barrel and operative to force a fluid-tight piston element 20 housed within the carpule to urge evacuation of the carpule contents. At the end of the syringe barrel 12 opposite the mounting of the plunger 18, there is provided an externally threaded stud or base, not shown, sized to receive a conventional, internally threaded hub member 22 mounting the needle 24 of a standard surgical needle and hub assembly.
As depicted in FIG. 1, in the course of capping/recapping a needle for discard or subsequent re-use, a conventional cap 26 (in which the needle and hub assembly typically comes as a sterile package) is held in a fashion therein typified preparatory to the insertion of the needle and hub assembly 22, 24. Once the assembly is secured within the cap 26, it can then be removed from the syringe 10 by a twisting action for replacement with a fresh assembly.
FIG. 2 again illustrates the initiation of a needle capping procedure, but in this case utilizing the capping device 30 according to the present invention. The greatly enhanced protection from accidental needle punctures in utilizing the subject device 30, when compared to the showing in FIG. 1 utilizing conventional capping device 26, becomes readily apparent.
It should be noted that FIG. 2 depicts a preferred manner of grasping the needle capping device comprising the present invention, namely in fisted fashion. It is recognized, however, that same users may, by virtue of habit or otherwise, prefer to grasp and hold the capping device in some manner different from that shown. In any case, the user will benefit from a greatly reduced chance of accidental needle punctures.
Turning now to the showings in FIGS. 3-5 for a more detailed understanding of the subject needle capping device 30, it is seen that such device is characterized by a conical section 32 tapering to a tubular section 34. The embodiment shown in FIGS. 3-5 is designed for one-time, throw-away usage, wherein the tubular section may be open-ended, but of sufficient length to shield the full length of the needle contemplated for use. The conical and tubular sections are preferably of single piece construction, as by injection molding.
The inner diameter of the tubular section, at least in a zone immediately adjacent its juncture with the conical section, is formed to define a socket 36, as best shown in FIG. 5, having a size and configuration to axially receive and snugly mate with the hub member 22 of a conventional surgical needle and hub assembly. To insure positive rotational gripping between the socket and hub member, longitudinally extending locking ribs 38 may be provided on the inside socket surface to better engage the ribbed surface of a typical needle hub member 22, as depicted in FIGS. 1-3. Preferably, a socket shoulder 40, as best viewed in FIG. 5, is formed at the interface between the tubular and conical sections and bounding the socket entrance to receive and seat hub flange 42 (see FIG. 3) formed at the base of hub member 22, to thereby limit the axial extent of hub member insertion into socket 36.
To optimize the hand fit and feel of the capping device and to provide an enhanced shielded area to the user, a radially outwardly extending rim 44 is integrally formed around the flared end of the conical section. Flattened segments 46 may be formed along the periphery of rim 44 to inhibit the device from rolling about when not in use. Optionally, to further improve gripping of the device and overall stiffness, there may be provided radially spaced ribs 48 extending axially along the outer surface of the tubular section.
Turning now to FIGS. 6 and 7, there is depicted a further embodiment of the present invention wherein a needle and hub assembly may readily be ejected from the capping device and discarded, to thereby enable reuse of the device once it has been properly sterilized. Such needle ejection is accomplished by the provision of spring biased plunger 50 mounted to reciprocate axially within the tubular section 34 at the end remote from conical section 32. Any suitable plunger biasing means may be employed, a coil spring 52 being symbolized in FIGS. 6 and 7. A retaining collar 54 is threaded or otherwise affixed on the end of the tubular section to house the plunger biasing element 52 and to retain the plunger 50 within the end of the tubular section 34. FIG. 6 depicts plunger 50 in its biased, needle receiving position, while FIG. 7 depicts the plunger in its depressed, needle ejecting position. It will be noted in comparing FIGS. 6 and 7, that the axial stroke distance of plunger 50 is at least equal to the axial length of hub member 22, as measured from hub flange 42 to the point of reduced hub diameter, i.e. the axial length of the hub member surface contacting the interior wall of socket 36 when the hub member 22 is fully inserted in such socket.
Though not illustrated, it is contemplated that the plunger retaining collar 54 may be modified to provide for axially shifting the biased locus of the plunger 50 to thereby accommodate varying needle lengths.
In striking a balance between comfortable hand-sizing and gripping base, on the one hand, and providing a suitably sized needle target area, it is preferred that the conical section 32 of the present capping device have a flared-end diameter within the range of approximately 30 to 35 mm. and an axial dimension within the range of approximately 15 to 20 mm.; the tubular section 34 have an external diameter of approximately 8 to 10 mm.; the rim 44 have a width of approximately 3 mm.
From the foregoing description and drawings, it will be appreciated that the present invention provides an economical and practical means for significantly enhanced protection from accidental surgical needle punctures at a time of heretofore unequalled concern over infectious disease transmissions by contaminated needles.
The present invention may be practiced in ways not here specifically set forth without departing from the spirit and essential characteristics of such invention. The herein described embodiments of the invention are, therefor, to be considered in all respects as merely illustrative, and not limiting, thereof. All changes and variations coming within the meaning and just range of equivalency of the appended claims are intended to be fully embraced therein. | The present invention involves a hand-held capping device for surgical needles designed to minimize the risk of accidental needle punctures, characterized by a conical, rimmed shield tapering to a tubular section, a socket being formed at the juncture of the shield with the tubular section in a configuration to receive and grip the hub portion of a conventional surgical needle assembly. The device may include mechanisms to effect needle assembly ejection and/or accommodate assemblies of varying needle length. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a U.S. National Phase application submitted under 35 U.S.C. §371 of Patent Cooperation Treaty application serial no. PCT/DE2007/001946, filed Oct. 30, 2007, and entitled TURBO ENGINE, which application claims priority to German patent application serial no. DE 10 2006 052 786.0, filed Nov. 9, 2006, and entitled TURBOMASCHINE, the specifications of which are incorporated herein by reference in their entireties.
TECHNICAL FIELD
The invention concerns a turbo engine, especially a gas turbine.
BACKGROUND
From DE 10 2004 037 955 A1 there is a known turbo engine with a stator and a rotor, wherein the rotor has rotating blades and the stator has a housing and guide blades. The rotating blades at the rotor side form at least one rotating blade ring, which at one radially outward lying end adjoins a radially inward lying wall of the housing, by which it is surrounded and with which it bounds a radial gap. The radially inward lying wall of the housing is also known as the inner ring or casing ring and serves in particular as the substrate for a run-in coating. Furthermore, from DE 10 2004 037 955 A1 it is known that the gap between the casing ring of the housing and the radially outward lying end of the rotating blade ring or each rotating blade ring can be adjusted or adapted in its size by servomechanisms to provide a so-called Active Clearance Control, so as to automatically influence the gap and ensure an optimal gap maintenance over all operating conditions. According to DE 10 2004 037 955 A1, the radially inward lying housing wall or the casing ring is segmented in the circumferential direction, and preferably each segment is assigned a separate servomechanism. The servomechanisms are preferably electromechanical actuators.
DE 101 17 231 A1 discloses a turbo engine with a stator and a rotor, wherein the gap between radially outward lying ends of the rotating blades and the radially inward lying housing wall can be adjusted by means of a pneumatic, i.e., pressurized air-operated, actuator unit of a rotor gap control module. The pneumatic actuator unit of the rotor gap control module disclosed there has an actuator chamber, a pressure chamber, and valves connecting the actuator chamber and the pressure chamber, and depending on the pressure prevailing in the actuator chamber sealing elements of the rotor gap control module are inflated so as to adjust or adapt the size of the gap between radially outward lying ends of rotating blades and the casing ring of the housing in the sense of a pneumatic Active Clearance Control.
DE 29 22 835 C2 and U.S. Pat. No. 5,211,534 disclose further turbo engines with a pneumatic or pressurized air-operated Active Clearance Control.
Thus, the turbo engine of DE 29 22 835 C2 has a stator and a rotor, while the gap between radially outward lying ends of the rotating blades and an inner ring or casing ring of a housing wall can be pneumatically adjusted. For this, the casing ring is connected to a support ring via flexible sidewalls, with the casing ring, the support ring and the side walls forming a bellows-like structure. By adjusting the pressure in a cavity defined by the bellows-like structure, the gap between radially outward lying ends of the rotating blades and the casing ring can be adjusted. The flexible sidewalls of DE 29 22 835 C2 are curved several times. Accordingly, seen in the axial direction, the sidewalls of DE 29 22 835 C2 curve inward into the cavity for some segments and outward from the cavity for some segments.
SUMMARY
Starting from the previously discussed background, the problem of the present invention is to create a new kind of turbo engine with a pneumatic Active Clearance Control.
According to a first aspect of the invention, a turbo engine is provided, wherein, in the region of the bellows-like structure or each bellows-like structure, the wall connecting the casing ring to the support ring is curved only once inwardly into the respective cavity, looking in the axial direction.
According to a second aspect of the invention, a turbo engine is provided, wherein, in the region of the bellows-like structure or each bellows-like structure, the wall connecting the casing ring to the support ring is curved only once outwardly from the respective cavity, looking in the axial direction.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred modifications of the invention will emerge from the subclaims and the following description. Sample embodiments of the invention are explained more closely by means of the drawing, without being restricted to these. This shows:
FIG. 1 , a cross section through subassemblies at the stator side of a turbo engine according to the invention;
FIG. 2 , a schematic representation of a bellows-like structure of the turbine per FIG. 1 ;
FIG. 3 , a schematic representation of an alternative bellows-like structure of a turbo engine; and
FIG. 4 , a cross section of a turbo engine in according with an alternative embodiment.
DETAILED DESCRIPTION
FIG. 1 shows a partial cross section through a stator of a compressor 10 of a turbo engine, wherein the stator comprises a housing 11 as well as several stationary guide blades 12 . The guide blades 12 on the stator side form so-called guide blade rings, which are arranged one behind the other looking in the axial direction. FIG. 1 shows a total of four stationary guide blade rings 13 , 14 , 15 and 16 at the stator side.
Besides the stator, the compressor 10 contains a rotor 40 not shown in FIG. 1 , the rotor being formed from several rotor disks, not shown, arranged one behind the other in axial direction 42 , each rotor disk carrying several rotating blades 44 , likewise not shown, alongside each other in the circumferential direction (see FIG 4 ). The rotating blades assigned to one rotor disk and arranged alongside each other in the circumferential direction form so-called rotating blade rings, while between every two neighboring guide blade rings 13 and 14 , 14 and 15 , and 15 and 16 , there is arranged a respective rotating blade ring 46 , not shown.
Besides the stator, the compressor 10 contains a rotor 40 not shown in FIG. 1 , the rotor being formed from several rotor disks, not shown, arranged one behind the other in axial direction 42 , each rotor disk carrying several rotating blades 44 , likewise not shown, alongside each other in the circumferential direction (see FIG. 4 ). The rotating blades assigned to one rotor disk and arranged alongside each other in the circumferential direction form so-called rotating blade rings 46 , while between every two neighboring guide blade rings 13 and 14 , 14 and 15 , and 15 and 16 , there is arranged a respective rotating blade ring 46 (see FIG. 4 ).
The housing 11 of the stator of the compressor 10 comprises a radially inward lying housing wall, while the radially inward lying housing wall forms a so-called inner ring or casing ring in the region of each rotating blade ring 46 at the rotor side, not shown in FIG. 1 , and encloses the respective rotating blade ring 46 radially on the outside. Besides the casing rings 17 of the radially inward lying housing wall, the housing 11 further comprises a radially outward lying housing wall 18 .
As already mentioned, the radially inward lying housing wall forms a so-called casing ring 17 in the region of each rotating blade ring at the rotor side (not shown), which encloses the rotating blade ring radially on the outside. Thus, between the radially outward lying ends of the rotating blades 44 of each rotating blade ring 46 and the respective casing ring 17 is formed a radial gap 48 ( FIG. 4 ), which is subject to considerable changes during the operation of the compressor, since on the one hand the rotating blades and the respective casing rings have different thermal behavior and on the other hand the rotating blades undergo a change in length 50 due to the centrifugal forces at work during operation.
It is quite difficult to maintain definite dimensions of the respective gap between the radially outward lying ends of the rotating blades of a rotating blade ring and the respective casing ring 17 during operation, yet it is of critical importance for optimized efficiency.
The present invention concerns only those details which can be used to exactly maintain radial gaps between radially outward lying ends of rotating blade rings and the respective casing ring 17 .
Per FIG. 1 , the casing rings 17 which extend between the guide blade rings 13 and 14 , as well as 15 and 16 , are connected by curved and elastically flexible walls 19 to a support ring 20 , the respective support ring 20 being arranged between the respective casing ring 17 and the radially outward lying housing wall 18 . The respective casing ring 17 , the support ring 20 , and the curved walls 19 extending between the respective casing ring 17 and the respective support ring 20 form a bellows-like structure 21 , having a cavity 22 . The bellows-like structure 21 and thus the cavity 22 fully surrounds and thereby encloses the rotating blade ring, looking in the circumferential direction.
By changing a pressure prevailing in the respective cavity 22 of the bellows-like structure 21 , the gap 48 between the respective casing ring 17 and the radially outward lying end of the respective rotating blade ring 46 can be adjusted pneumatically. If the pressure is increased in the cavity 22 of the respective bellows-like structure 21 , the respective radially inward lying casing ring 17 can be forced radially inward and the respective radially outward lying support ring 20 radially outward. By reducing the pressure in the cavity 22 of the respective bellows-like structure 21 , an opposite deformation of the respective bellows-like structure 21 can be accomplished.
In the preferred embodiment of FIG. 1 , the curved and elastically flexible walls 19 of the bellows-like structures 21 are curved only one time inward into the respective cavity 22 , looking in the axial direction. In the region of a vertex of the curve, wall segments of the respective wall 19 subtend a relatively obtuse angle α larger than 90 degrees. This is described hereafter in reference to FIG. 2 , which shows a schematic representation of a bellows-like structure 21 .
Thus, FIG. 2 shows that in the region of a vertex 29 of the curve, the wall segments of the respective wall 19 subtend an obtuse angle α. For such curved walls 19 , two effects are superimposed when the pressure increases in the respective cavity 22 of the respective bellows-like structure 21 .
First, due to the pressure rise in the cavity 22 , the respective casing ring 17 and the respective support ring 20 are forced apart, looking directly in the radial direction. Secondly, this radial forcing apart of the casing ring 17 and support ring 20 is supported or at least not hindered by a toggle-like effect of the curved walls 19 . The curved walls 19 are essentially subjected only to compressive forces.
According to FIGS. 1 and 2 , the bellows-like structure 21 has a greater radial dimension than its axial dimension. Preferably, the walls 19 of the bellows-like structure 21 have a greater radial dimension than their axial dimension.
In the sample embodiment shown in FIG. 1 , the curved walls 19 of each bellows-like structure 21 have a roughly constant wall thickness, looking in the radial direction. In contrast to this, it is also possible for the curved walls 19 to have a variable wall thickness, looking in the radial direction.
As can likewise be seen from FIG. 1 , the radially inward lying casing ring 17 of each bellows-like structure 21 has a smaller wall thickness that the respective radially outward lying support ring 20 . The support ring 20 of each bellows-like structure 21 is accordingly designed with a greater wall thickness than the respective casing ring 17 . This ensures that deformations of the bellows-like structure 21 brought about by change of pressure prevailing in the particular cavity 22 act primarily on the casing ring 17 .
Moreover, one can infer from FIG. 1 that the casing ring 17 of each bellows-like structure 21 has a radially outward curved contour 23 , protruding into the respective cavity 22 , in a middle region, looking in the axial direction.
Thanks to this, upon deformation of the casing ring 17 due to a pressure change in the cavity 22 of the respective bellows-like structure 21 , an outer contour 28 of the casing ring 17 is displaced essentially only parallel, looking in the radial direction, so that a gap between the casing ring 17 and the rotating blade ring can be adjusted exactly.
Each bellows-like structure 21 is coordinated with at least one pressurized air line 24 , in order to either bring pressurized air into the cavity 22 of the respective bellows-like structure 21 or drain pressurized air from it. For an easier representation, FIG. 1 shows one such pressurized air line 24 only for the bellows-like structure 21 positioned between the two guide blade rings 13 and 14 , looking in the axial direction. Each bellows-like structure 21 is coordinated with at least one such pressurized air line 24 . The more such pressurized air lines 24 are present per bellows-like structure 21 , the quicker pressurized air can be taken to or drained from the respective cavity 24 .
In the sample embodiment of FIG. 1 , one bellows-like structure 21 is arranged between the two guide blade rings 13 and 14 , and also between the two guide blade rings 15 and 16 , while no such bellows-like structure is present between the two guide blade rings 14 and 15 . Instead, according to FIG. 1 , a sensor unit 25 is arranged between the two guide blade rings 14 and 15 and, thus, in the region of a rotating blade ring arranged between the former.
With the sensor unit 25 , one can measure at least the radial dimension of the gap 48 between the corresponding rotating blade ring 46 and the casing ring 17 surrounding this rotating blade ring. Via a signal line 26 , the sensor unit 25 transmits the corresponding actual value to a feedback control mechanism 52 ( FIG. 4 ) where the feedback control mechanism compares the actual value against a setpoint and, depending on this, adjusts the pressure prevailing in the cavities 22 of the bellows-like structures 21 so that the actual value comes near the setpoint.
It can be provided that the pressurized air feed to the cavities 22 and the pressurized air drain from the cavities 22 of the bellows-like structures 21 can be adjusted by individual valves, in order to individually adjust the pressure prevailing in the cavities 22 of the two bellows-like structures 21 and thus individually adjust the dimension of the radial gap between the casing ring 17 and the corresponding rotating blade ring as a function of the respective radial dimension of the rotating blade ring.
Alternatively, as best seen in FIG. 4 , it can be provided to adjust the pressurized air feed 24 to the cavities 22 of the bellows-like structures 21 and the pressurized air drain from same by a common valve 54 . Different deformations of the bellows-like structures 21 required due to different radial dimensions 50 of the particular rotating blade ring 46 of the compressor 10 can then be achieved by an adapted curvature of the curved walls 19 and/or an adapted wall thickness of the curved walls 19 and/or by an adapted radial dimension of the bellows-like structures 21 . For example, in the embodiment shown in FIG. 4 , the profiles of the first curved walls 19 disposed between guide rings 13 and 14 are adapted to produce a different deformation of the associated bellows-like structure 21 (denoted by deformed casing ring 17 ′, shown in broken line) than the profiles of the second curved walls 19 disposed between guide rings 15 and 16 produce in the associated bellows-like structure 21 . In particular, the curvature of the curved walls 19 of the bellows-like structure 21 disposed between guide rings 13 and 14 is different (i.e., greater than) than the curvature of the curved walls 19 of the bellows-like structure 21 disposed between guide rings 15 and 16 . Further, the wall thickness of the curved walls 19 of the bellows-like structure 21 disposed between guide rings 13 and 14 is different (i.e., less than) than the wall thickness of the curved walls 19 of the bellows-like structure 21 disposed between guide rings 15 and 16 . These differences between the profiles of the first curved walls 19 disposed between guide rings 13 and 14 and the profiles of the second curved walls 19 disposed between guide rings 15 and 16 result in different deformations of the respective bellows-like structures 21 .
According to FIG. 1 , the two bellows-like structures 21 are divided in the axial direction by dividing planes extending in the radial direction, and the two axial halves of the bellows-like structures 21 are welded together during the fabrication process. Alternatively, it is also possible to divide the bellows-like structures 21 in the radial direction.
According to FIGS. 1 and 2 , each wall 19 in the region of each bellows-like structure 21 is curved only once inward into the respective cavity 22 , looking in the axial direction.
In contrast with this, it is also possible, as diagrammed in FIG. 3 , for each curved, elastically flexible wall 19 in the region of each bellows-like structure 30 to be curved only once outward from the respective cavity 22 , looking in the axial direction. Wall segments of the respective wall 19 in the region of a vertex 29 of the curvature subtend a relatively acute angle β smaller than 90 degrees.
According to FIG. 3 , the wall segments of the wall 19 subtending the angle β extend basically in the axial direction. Like the casing ring 17 and the support ring 21 , they are exposed to the pressure prevailing in the cavity 22 and thereby support a radial moving apart of the casing ring 17 and support ring 20 when pressure increases in the cavity 22 . A negative toggle effect in this variant is also totally eliminated by the acute angle β.
The bellows-like structure 30 per FIG. 3 has a larger axial dimension than its radial dimension; in particular, the walls 19 of the bellows-like structure 30 have a larger axial dimension than their radial dimension. | A turbomachine, especially a gas turbine, includes a rotor having rotating blades and a stator having a housing and guide blades. The rotating blades form at least one rotating blade ring, which at one radially outward lying end adjoins an inner ring or casing ring of the housing, thereby defining a gap therebetween. The casing ring is connected to a support ring via curved walls, which together with the casing ring and the support ring bound a cavity and form a bellowslike structure. By changing the pressure prevailing in the cavity of the respective bellowslike structure, the gap between the casing ring and the radially outward lying ends of the respective rotating blade ring can be pneumatically adjusted. | 5 |
GOVERNMENT SUPPORT
This invention was made with government support under contract number 1214 awarded by the National Institutes of Health. The U.S. government has certain rights in the invention.
FIELD OF THE INVENTION
The invention relates generally to the field of target tracking. In particular, the invention relates to apparatus and methods for reflectance-based servo tracking for image stabilization and precision target tracking.
BACKGROUND OF THE INVENTION
Active servo tracking systems are used in numerous military, industrial, and medical applications. In operation, active servo tracking systems utilize information about a target's motion to correct the physical position of an object to be stabilized in a target frame of reference. The information about the target's motion may be obtained by numerous techniques such as direct position measurements, position correlation, and velocity sensing.
Direct position measurement techniques for obtaining information about a target's motion typically utilize position sensitive detectors, such as quadrant detectors, to detect a "hot spot" associated with the target. Position correlation techniques for obtaining information about a target's motion compare previously stored images of the target to the current image at predetermined time intervals. The resulting image overlap or correlation function is utilized to determine the target displacement.
Velocity sensing techniques for obtaining information about a target's motion typically utilize a signal proportional to the rate of displacement in the frequency domain. The signal is then integrated to give target position information. There are numerous velocity sensing techniques known in the art such as coherent laser-based Doppler and speckle methods.
U.S. Pat. No. 4,856,891 describes an eye fundus tracking system that utilizes active servo tracking and correlation. The system includes a laser source that projects a tracking strip of coherent light on the fundus and optics for producing an image of reflected light from the tracking strip onto a detecting element. The system also includes a means for scanning the intensity profile of the image strip and electronics for analyzing the scanned intensity profile and for providing correction signals which direct the optical path of both the tracking laser beam and a diagnostic laser beam to a fixed position on the fundus. The system, however, is relatively complex to implement.
Numerous applications, such as ophthalmologic and other micro-surgical procedures, require high-speed positioning with accuracy in the cellular dimension range. In addition, it is desirable for such tracking systems to utilize low-power incoherent tracking beams.
SUMMARY OF THE INVENTION
It is a principal object of this invention to provide apparatus and methods for tracking a feature on a target surface and continually providing analog corrections to tracking mirrors in real time by utilizing a low-power incoherent tracking beam to detect the movements of a reference feature on the target and confocal reflectometry to monitor the reflection from the tracking beam's current position. It is another object of this invention to utilize small, periodic, transverse oscillations in the tracking beam and phase sensitive detection of the reflectance variations to generate error signals which are utilized to compensate the target displacement.
It is another object of this invention to provide independent steering of a tracking beam and a therapeutic beam by a balanced "scan and de-scan" technique. It is another object of this invention to provide a high-speed fundus tracking system that utilizes confocal reflectometry for retinal photocoagulation.
Accordingly, the present invention features a tracking system for tracking a reference feature on a target surface. The tracking system includes a dithering device positioned in an optical path of a tracking beam. The tracking beam may be formed from a light emitting diode or from numerous other low-power coherent or incoherent light sources.
The dithering device dithers the tracking beam in a first and a second direction with an oscillatory motion having a first and a second phase, respectively. The first and second phases of oscillatory motion may be orthogonal to each other. The dithering device may comprise a pair of orthogonally mounted galvanometers operatively connected to reflectors.
The tracking system also includes a tracking device for controlling the position of a therapeutic beam relative to a target and for controlling the position of the tracking beam relative to a reference feature. The reference feature may be associated with an eye or may be a retro-reflecting material. The tracking device includes a first input for accepting a first direction control signal and a second input for accepting a second direction control signal. The first and second direction control signals cause the tracking device to move the therapeutic beam in the first and second directions, respectively. The tracking velocity of the tracking device may be proportional to the product of a dither frequency of the dithering device and a spatial dimension of the reference feature.
The tracking system also includes a reflectometer positioned in an optical path of a reflected tracking beam. The reflectometer provides an output signal with a phase corresponding to the phase of the reflected tracking beam. The reflectometer may be a confocal reflectometer.
The tracking system also includes a signal processor for comparing the phase of the reflectometer output signal to the phases of the oscillatory motion in the first and second directions. The signal processor generates the first and second direction control signals which are coupled to the first and second inputs of the tracking device, respectively. The first and second direction control signals cause the therapeutic beam to track relative to the reference feature.
The present invention also features an eye tracking system for tracking a reference feature associated with an eye. The eye tracking system includes a first pair of reflectors. The first reflector is positioned in an optical path of an incident and reflected tracking beam. The second reflector may be a beamsplitter that passes a coagulating beam in transmission and reflects the tracking beam in reflection. The first pair of reflectors controls the position of the tracking beam. The tracking beam may be formed from a light emitting diode or from numerous other low-power incoherent light sources.
The eye tracking system also includes a pair of dither drivers operatively connected to the first pair of reflectors. The dither drivers dither the first reflector in a first direction and the second reflector in a second direction with an oscillatory motion having a first and a second phase, respectively. The first and second phases may be orthogonal. The pair of dither drivers may be orthogonally mounted galvanometers operatively connected to the first pair of reflectors.
The eye tracking system also includes a second pair of reflectors for positioning the tracking beam onto a reference feature in an eye and for positioning the coagulating beam onto a target in the eye. The eye tracking system also includes a pair of tracking drivers for controlling the position of the second pair of reflectors. The pair of tracking drivers is operatively connected to the second pair of reflectors and comprises a first input for accepting a first direction control signal and a second input for accepting a second direction control signal. The first and second direction control signals cause the pair of tracking drivers to move the second pair of reflectors in the first and the second direction, respectively. A tracking velocity of the pair of tracking drivers is proportional to the product of a dither frequency of the pair of dither drivers and a spatial dimension of a reference feature.
The eye tracking system also includes a reflectometer positioned in the optical path of the reflected tracking beam. The reflectometer, which may be a confocal reflectometer, provides an output signal with a phase corresponding to a phase of the reflected tracking beam.
The eye tracking system also includes a signal processor for comparing the phase of the reflectometer output signal to the phases of the oscillatory motion in the first and second directions. The signal processor generates the first and the second direction control signals which are coupled to the first and second inputs of the tracking driver, respectively. The first and second direction control signals cause the coagulating beam to track relative to the reference feature.
The eye tracking system may include a shutter for blanking the coagulating beam so that a surgeon can precisely control when the coagulating beam is delivered to the target. The eye tracking system may also include an offset signal generator operatively coupled to the dither driver and to the tracking driver for displacing the coagulating beam with respect to the tracking beam a predetermined distance. When a "scan" signal is input to the tracking driver to reposition the therapeutic beam, an offsetting "de-scan" signal is input to the dither driver. Such an offset signal generator will significantly increase the speed at which the coagulating beam can be translated from one target to another target.
The present invention also features a method of tracking that includes directing a tracking beam to a reference feature. The tracking beam is dithered in a first and a second direction with an oscillatory motion having a first and a second phase, respectively. A reflector is positioned in an optical path of a therapeutic beam. The reflector may also be positioned in an optical path of the tracking beam.
The phase of a reflected tracking beam reflected from the reference feature is measured. The phase of the reflected tracking beam is compared to the first and the second phase of the oscillatory motion. The method also includes repositioning the reflector a distance related to the comparison of the phase of the reflected tracking beam and the first and the second phases of the oscillatory motion where the distance causes the therapeutic beam to track a displacement of the reference feature. In addition, the method may include displacing the therapeutic beam relative to the tracking beam a predetermined distance. The displacement will increase the speed at which the coagulating beam can be translated from one target to another target.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention is described with particularity in the appended claims. The above and further advantages of this invention may be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic diagram of a tracking system which embodies the invention.
FIG. 2 is a functional block diagram of a signal processor utilized in the tracking systems which embody the invention.
FIG. 3 is a schematic diagram of the optics for an eye tracking system which embodies the invention.
FIG. 4A-C illustrates the operation of the signal processor.
DETAILED DESCRIPTION
FIG. 1 is a schematic diagram of a tracking system 10 which embodies the invention. The tracking system 10 tracks a target 12 relative to a reference feature 14. The reflectivity of the reference feature 14 is different from the reflectivity of an adjacent background area 16 at the wavelength of a tracking beam 18. The reference feature 14 may be any approximately axisymmetric feature of appropriate size and reflectivity contrast.
The reference feature 14 may be associated with an eye or may be a retro-reflecting material. The reference feature 14 may be photocoagulation eye lesions which are useful for retinal laser surgical application. Photocoagulation lesions are commonly used for marking a physical reference position on the retina. However, many retinal features have a high enough reflectivity contrast with the background area 16 to be suitable as reference features.
The tracking beam 18 locks onto the reference feature 14 by inducing small, periodic, transverse oscillations or dithers in the tracking beam. The tracking beam 18 may be any low-power light beam that detects movement of the reference feature 14. The tracking beam 18 may be formed from a light emitting diode or from numerous other low-power incoherent light sources. Typically, the reference feature 14 is locked onto by the tracking beam in two dimensions with a circular dither.
The tracking system 10 includes a dithering device 20 positioned in an optical path 22 of the tracking beam 18. The dithering device 20 may comprise a pair of orthogonally mounted galvanometers scanner-driven mirrors (not shown). Galvanometers with low armature inertia can be used to achieve a high-speed tracking response.
The dithering device 20 dithers the tracking beam 18 in a first 19 and a second direction 21 with an oscillatory motion having a dither frequency with a first and a second phase, respectively. The dithering device 20 produces a circular dither at the reference feature 12 when the oscillatory motions, in the first and second direction, have identical amplitudes and have a phase difference of 90 degrees.
The tracking system 10 also includes a tracking device 24 for controlling the position of a therapeutic beam 26 relative to the target 12 and for controlling the position of the tracking beam 18 relative to the reference feature 14. The therapeutic beam 26 is typically a high-power coagulating beam. A blanking element 28 may be positioned in an optical path 30 of the therapeutic beam 26 for controlling when the therapeutic beam 26 is delivered to the target 12.
The tracking device 24 includes a first input 32 for accepting a first direction control signal, and a second input 34 for accepting a second direction control signal. The first and second direction control signals cause the tracking device 24 to move the therapeutic beam 26 in the first and the second direction, respectively. The tracking velocity of the tracking device 24 may be proportional to the product of the dither frequency and a spatial dimension of the reference feature 12.
The tracking system 10 also includes a reflectometer 36 positioned in an optical path 38 of a reflected tracking beam 40. The reflectometer 36 provides an output signal with a phase corresponding to a phase of the reflected tracking beam 40. The reflectometer 36 may be a confocal reflectometer. When the tracking beam 18 traverses a region of changing reflectance (not shown), a corresponding variation in the output signal of the reflectometer 36 occurs. The reflectometer output signal varies synchronously (when appropriately corrected for phase shifts) with the oscillatory motion caused by the dither driver 20.
The tracking system 10 also includes a signal processor 42 for comparing the phase of the reflectometer output signal to the phases of the oscillatory motion in the first and second directions. The signal processor 42 generates the first and the second direction control signals which are coupled to the first 32 and second input 34 of the tracking device 24, respectively. The first and second direction control signals cause the therapeutic beam 26 to track relative to the reference feature 14. The maximum tracking velocity of such a tracking system is determined by the dither frequency and a diameter 44 of the reference feature 14.
The signal processor 42 may include an offset signal generator 44, that is operatively coupled to the dithering device 20 and to the tracking device 24 via the signal processor 42, for displacing the therapeutic beam 26 with respect to the tracking beam 18 a predetermined distance. Such an offset signal generator 44 can be utilized to increase the speed at which the therapeutic beam 26 is translated from one target to another target. By providing equal and opposite voltages to the dithering device 20 and to the tracking device 24, the therapeutic beam 26 can be translated relative to the tracking beam 18 much more quickly than the maximum tracking velocity.
FIG. 2 is a functional block diagram 100 of the signal processor 42 (FIG. 1) utilized in the tracking systems which embody the invention. The signal processor 42 includes an oscillator 102 having a first 104 and a second output 106. The first 104 and the second output 106 have a first and a second phase, respectively, which differs by 90 degrees. The first 104 and the second output 106 of the oscillator 102 are coupled to a first 108 and a second dither driver 110 of the dithering device 20 (FIG. 1) and cause the transverse dithers in the first and the second direction with equal amplitude and a phase difference of 90 degrees.
The signal processor 100 also includes a phase-sensitive detector 116 that may comprise a combination of a narrow-band amplifier circuit (not shown), such as an analog multiplication or mixing circuit, and a low-pass filter (not shown). The phase-sensitive detector 116 electronically compares the phase of the reflectometer signal to the phases of the oscillatory motion in the first and second directions and generates a first and second phase comparison signal at a first 118 and second output 120, respectively.
The first and second phase comparison signals comprise DC offset voltages which are proportional to the amplitude of the components of the reflectometer signal which are in phase with the dither signals. These DC offset voltages are vector correction or error voltages that are proportional to the displacement from equilibrium per dither cycle.
The signal processor 100 also includes an integrator 122 having a first 112 and a second input 114 connected to the first 118 and second output 120 of the phase-sensitive detector 116. The integrator 122 produces a first and a second integrated signal of the first and the second phase comparison signal, respectively. In addition, the signal processor 100 may include a first 128 and a second trim voltage power supply 130 which has a first 132 and a second trim voltage output 134. The first 132 and the second trim voltage output 134 are summed at a node 135 with the first 124 and the second output 126 of the integrator 122. The first 128 and second trim voltage supply 130 may be used to compensate for voltage drifts in the electronics of the signal processor 100.
The signal processor 100 also includes an offset signal generator 136 that accepts the summed outputs of the trim voltage supplies 128, 130 and the integrator 122 at a first 140 and a second 142 input. The offset signal generator 136 produces a first and a second directional control signal at a first 144 and a second output 146, respectively. The first and a second directional control signal are connected to a first 152 and a second tracking driver 154 of the tracking device 24 (FIG. 1).
The offset signal generator 136 also produces a first and a second offset signal at a third 148 and a fourth output 150. The third 148 and the fourth output 150 of the offset signal generator are connected to the first 108 and the second dither driver 110 of the dithering device 20 (FIG. 1). The offset signal generator 136 may be utilized to displace the therapeutic beam 26 (FIG. 1) with respect to the tracking beam 18 (FIG. 1) a predetermined distance. The offset signal generator 136 can greatly increase the speed at which the therapeutic beam 26 is translated from one target to another target. By providing equal and opposite voltages to the dither and the tracking drivers, the therapeutic beam can be translated relative to the tracking beam 18 much more quickly than the maximum tracking velocity.
FIG. 3 is a schematic diagram of optics for an eye tracking system 200 which embodies the invention. The eye tracking system 200 tracks a target 202 associated with an eye (not shown) relative to a reference feature 204. The reflectivity of the reference feature 204 is different from the reflectivity of a background area 206.
The eye tracking system 200 includes a source of radiation 208 for generating an incident tracking beam 210. The incident tracking beam 210 may be collimated by a lens 212. A beamsplitter 214 may divert a portion of the incident tracking beam 210 to an absorbing stop 216. A second lens 218 may be used to focus the incident tracking beam emerging from the beamsplitter 214 onto the target 202.
A first pair of reflectors comprising a first 220 and a second reflector 222 is positioned in an optical path 224 of a tracking beam 210. The first pair of reflectors controls the position of the tracking beam 210. The second reflector 222 may be a beamsplitter 222 that reflects the tracking beam 210 in reflection and that passes a coagulating beam 226 in transmission. The beamsplitter 222 may be a dichronic beamsplitter that efficiently reflects at the tracking beam wavelength and that transmits without significant attenuation at the coagulating beam wavelength. Utilizing such a beamsplitter both reduces the optical path lengths of the tracking 210 and the coagulating beam 226, and reduces the number of optical components necessary to realize a practical system.
A first 228 and a second dither driver 230 are operatively connected to the first 220 and the second dither reflector 222, respectively. The first 228 and second dither driver 230 dithers the first reflector 220 in a first direction and the second reflector 222 in a second direction with an oscillatory motion having a dither frequency and a first and a second phase, respectively. The first and second phases may be orthogonal. The pair of dither drivers may be orthogonally mounted galvanometers operatively connected to the first pair of reflectors.
The required dither frequency depends upon several factors. For example, if the tracking beam is imaged on the retina of an eye at unit magnification, a two kilohertz dither frequency will correspond to approximately a 50 μm displacement per dither cycle at a target velocity of 10 cm/sec (greater than 300 degrees/sec in an eye). Such a dither frequency is sufficient to track a coagulating laser with a spot size of approximately 400 μm.
The eye tracking system 200 also includes a second pair of reflectors for positioning the tracking beam 210 onto the reference feature 204 and for positioning the coagulating beam 226 onto the target 202. The second pair of reflectors comprises a first 232 and a second tracking reflector 234. A pair of tracking drivers is operatively connected to the second pair of reflectors for controlling the position of the second pair of reflectors.
The pair of tracking drivers comprises a first 236 and a second tracking driver 238. The first 236 and second tracking driver 238 has a first and a second input (not shown) for accepting a first and a second direction control signal, respectively. The first and second direction control signals cause the pair of tracking drivers to move the second pair of reflectors in the first and the second direction, respectively. A tracking velocity of the pair of tracking drivers may be proportional to the product of a dither frequency of the pair of dither drivers and a spatial dimension of the reference feature 204.
The second pair of reflectors directs the tracking beam 210 to the target 202 where a reflected tracking beam 240 is directed back into the optical path 224. The reflected tracking beam 240 is consequently "de-scanned" through the first and second pair of reflectors. The lens 218 collects and collimates the reflected tracking beam 240. A portion of the reflected tracking beam 241 is reflected by the beamsplitter 214 to a focusing lens 242.
A reflectometer 244 is positioned in an optical path 246 of the reflected tracking beam 246 after the focusing lens 242. The reflectometer 244 may be a confocal reflectometer. The portion of the reflected tracking beam 241 is focused onto a confocal aperture 248. A diameter 250 of the confocal aperture 248 may be approximately the size of an image (not shown) of the reference feature 204. The reflectometer 244 provides an output signal with a phase corresponding to a phase of the reflected tracking beam 240.
The coagulating beam 226 is directed at a beamsplitter 252 which may divert a portion of the coagulating beam 226 to the absorbing stop 216. A lens 254 may be used to collimate the incident tracking beam emerging from the beamsplitter 252. A reflector 256 directs the coagulating beam 226 to the beamsplitter 222. The eye tracking system 200 may include a shutter (not shown) in an optical path 258 of the coagulating beam 226 for blanking the coagulating beam 226 so that a surgeon can control when the coagulating beam 226 is delivered to the target 202. The tracking system 100 may also include a camera 260 which views the optical path 258 to the target 202. An image received by the camera 260 is stabilized by the tracking system 200.
The eye tracking system 200 utilizes a signal processor (not shown) for comparing the phase of the reflectometer 244 output signal to the phases of the oscillatory motion in the first and second directions. The signal processor generates control signals which are coupled to the pair of tracking drivers 236, 238. The first and second direction control signals cause the coagulating beam to track relative to the reference feature.
FIG. 4A-C illustrates the operation of the signal processor. A dither circle 300 and an image of the reference feature 302 is schematically illustrated in three relative positions. Also, the oscillatory motion in the first 304 and second direction 306 with the first and the second phase, respectively, is illustrated. In addition, the output signal 308 of the reflectometer 36 (FIG. 1) is illustrated as a function of time. The corresponding first 310 and the second direction control signals 312 are also shown. Moreover, a tracking lock signal 314 is illustrated.
FIG. 4A illustrates the operation of the signal processor 42 (FIG. 1) when the dither circle 300 is partially within the image of the reference feature 302. The reflectometer produces a synchronous output signal 308 with a phase that depends on the direction in which the image of the reference feature 302 is displaced from the dither circle 300. The signal processor consequently generates a first and a second direction control signal proportional to an error in the first and the second direction. In addition, the signal processor generates a tracking lock signal 314 that indicates that the dither circle is locked onto the image of the reference feature 302.
FIG. 4B illustrates the operation of the signal processor when the dither circle 300 is centered and locked onto the image of the reference feature 302. The signal processor generates null first 310 and a second direction control signal 312. In addition, the signal processor generates a tracking lock signal 314 that indicates that the dither circle 300 is locked onto the image of the reference feature 302.
FIG. 4C illustrates the operation of the signal processor when the dither circle 300 is outside the image of the reference feature 302. The reflectometer output signal is low which indicates a loss of tracking. The signal processor generates a null first 310 and second direction control signal 312. In addition, the signal processor generates a null tracking lock signal 314 that indicates that the dither circle 300 is not locked onto the image of the reference feature 302.
EQUIVALENTS
While the invention has been particularly shown and described with reference to specific preferred embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | Apparatus and methods for tracking a feature on a target surface and continually providing analog corrections to tracking mirrors in real time by utilizing a low-power incoherent tracking beam to detect the movements of a reference feature on the target and confocal reflectometry to monitor the reflection from the tracking beam's current position are described. The apparatus includes a dithering device for dithering the tracking beam in a first and a second direction with an oscillatory motion, a tracking device for controlling the position of a therapeutic beam relative to a target and for controlling the position of the tracking beam relative to a reference feature, a reflectometer for providing an output signal with a phase corresponding to a phase of the reflected tracking beam, and a signal processor for comparing the phase of the reflectometer output signal to the phases of the oscillatory motion and for controlling the tracking device so that the therapeutic beam to tracks relative to the reference feature. | 6 |
BACKROUND OF THE INVENTION
It is known that economy of production in modern weaving is essentially based on two factors:
1--high productivity of the machines (looms);
2--the shortest possible dead times for changing the articles and for preparing the changed articles.
Both of these factors are influenced by the adjustment of the weft yarn tension. In fact, the efficiency and thus the productivity of a loom--especially in the case of a high--performance loom are greatly affected by the various weft tension adjustments, as well as the weft tension variations in relation to the desired, but unachieved continuous characteristics as concern dyeing pigments, spooling oils and production processes in gerneal. Furthermore, a loom working with a new yarn, or with a yarn belonging to a different lot, may require--and it usually does--a new tension adjustment; this is now done by manual intervention and the speed of the adjustment depends on the skill of the technician.
The present invention proposes to automate the process of weft yarn tension adjustment in weaving looms.
It is known that most of these looms and, above all, the modern looms with continuous weft feed, are equipped with a weft feeder having yarn brake means, and with a sensor controlling the weft picking, or warp stop motion device, usually positioned downstream of the brake means and upstream of the device for changing the colors in the loom.
SUMMARY OF THE INVENTION
In a loom thus equipped, the present invention provides for a system to automatically control the tension of the weft yarns fed thereto, characterized in that it makes use of signals from the warp stop motion device, representing the value of weft yarn tension, which are suitably processed into an electronic interface circuit, so as to control, through an actuator, the braking of the yarn and to restore its tension as desired.
The desired tension can be a reference tension preset in the electronic interface circuit, or it can be a tension already prearranged to be variable in the loom working cycle, in which case it is modulated by means of the signal from the warp stop motion device.
As an alternative to the signals from the warp stop motion device, use can be made--even if the costs will be slightly higher--of signals representing the value of weft yarn tension, sent from a special tensiometer arranged on the weft yarn path between the weft feeder and the loom.
In order to control weft yarn braking, the actuator may act on the brake means already provided at the outlet of the weft feeder, or on a braking device provided for the purpose downstream of the weft feeder.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is now described in further deatail, with reference to the accompanying drawing, in which:
FIGS. 1 and 2 are schematic side views illustrating two different embodiments of the system according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The diagram of FIG. 1 illustrates a continuous weft loom 1, to which the weft yarn is fed by a weft feeder 2 having a weft yarn winding drum 3 on which acts a brake means 4.
A warp stop motion device 5 is arranged between the weft feeder 2 and the loom 1, upstream of the yarn-changing device.
According to the invention, the warp stop motion device is of the type adapted to send a signal of intensity proportional to the rubbing of the weft being picked onto a specially prearranged element 6 therof, that is, a signal proportional to the tension of said weft.
Always according to the invention, said signal--suitably processed in a special electronic interface circuit 7--is sent to an actuator 8 provided to control, by means of suitable leverages 9, the brake means 4 of the weft feeder 2. The braking action imparted by said means will thus depend on the weft yarn tension detected by the warp stop motion device 5.
The diagram of FIG. 2 illustrates a continuous weft feed loom 1, with which there are still associated a weft feeder. 2, a warp stop motion device 5 of the same type as the previous embodiment an electronic circuit 7 to process the signals sent from the warp stop motion device, and an actuator 8, but this latter, instead of controlling the brake means of the weft feeder 2, acts on an independent brake 10, provided downstream of said feeder 2.
In either case, once a reference tension value--deemed optimal for the working being carried out on the loom--has been preset in the interface circuit 7, any variation in respect of said value of the tension of the yarn f, detected by the warp stop motion device 5, produces a control on the brake means by the actuator 8, which is adapted to restore the tension to the desired reference value. Thus, if there is less tension, the braking action will be increased (thereby to increase the tension of the yarn f). On the other hand, if the tension is higher, the braking action will be reduced (in order to reduce the tension of the yarn f).
A further embodiment of the system according to the invention, which it has been deemed superfluous to illustrate in the drawings, provides for the use --as an alternative to the signals from the warp stop motion device--of signals representing the value of weft yarn tension sent by a sensor--suitably a tensiometer--provided for the specific purpose of the invention. Said tensiometer may be positioned upstream or downstream of the warp stop motion device 5, as long as it is on the path of the weft yarn between the weft feeder and the loom. In this case, the warp stop motion device may be of the conventional type. It is to be deemed that the system, thus modified--even if less economic than those heretofore described and illustrated by FIG. 1 and 2--turns out to be more efficient, as it can make use of a sensor more adaptable to the purposes of the invention.
With each of the described embodiments of the system according to the invention--according to the nature and type of interaction between the actuator and the brake means (usually mechanical or magnetic)--it will be possible to rely on different response times, so as to obtain adjustments during the actual working cycle of the loom in which the work is being performed, or to base the adjustment on statistical concepts and thus obtain the adjustment after a certain number of cycles.
According to the weft picking characteristics, which are quite different between single-width and double-width looms, it is even possible to select between an immediate and a statistical adjustment, according to loom width.
In the event of the brake means operating in a variable way during the loom working cycle, it will not be possible to fix a reference value of the tension with which to compare the instantaneous value taken by the warp stop motion device, but a modulation of the ordinary signal controlling the action of the actuator 8 will be carried out by the signals sent from the warp stop motion device 5.
It is understood that each of the weft yarns to be picked in the loom shed has to be in a position to self-adjust its own tension in the way explained above. The sensor may however be a single sensor, if it has more possibilities of control.
The electronic interface circuit 7 will have to provide for a digiting member, for a monitoring member and for a logic. Said circuit should perform the following functions:
1--take from the code of the article being produced, containing all the working parameters of the loom for that article, the tension reference value; alternatively, said value may be input directly by the operator;
2--detect working tension values, even in different positions of the picking cycle: the operator selects the value which he deems more appropriate as reference value (according to loom behaviour and to the quality of the fabric). Said value is repeated for the other yarns if they have the same characteristics (the information being supplied by a code or by the operator) on the same loom and/or (by connection to the mains) also on other looms;
3--if braking must be modulated during operating, the tension parameters can be defined in various positions each constituting reference value for each cycle: this means that the actuator will modulate its cycle in a different way for each position;
4--the loom can also be supplied with a data-base through which, having indicated the type of weft, the loom speed and width it is possible to choose the reference value of the tension of the yarn f;
5--it is also possible to provide for a connection between the reference parameter and the working of the loom: this means that, upon weft breakage in certain steps, it is possible to operate a change in the reference tension, which will thus be continuously optimized on each yarn, in order to compensate any relative differences between the systems. In this case, a so-called "open system" will be realized. | In a system for automatically controlling the tension of weft yarns fed to a loom with continuous weft feed, the extent of braking of the weft yarn is controlled based on signals output from a device for measuring weft yarn tension. Specifically, signals from a weft yarn tension measuring device are output to an electronic interface unit, which processes those signals and directs an actuator to brake the weft yarn more heavily when the detected tension is below a predetermined level, and less heavily when the detected tension is above a predetermined level. | 3 |
BACKGROUND OF THE INVENTION
This invention discloses frictional rotational energy transfer devices, such as drum-type brakes and band-type clutches, containing two concentric mating members, in which the external member may be contracted or the internal member may be expanded, by magnetic force, or both members may change, so that contact occurs between intervening friction members when the appropriate magnetic fields are established, and rotational energy may be transferred from one mating member to the other.
In the prior art magnetic shrink fits are disclosed, in which an internal mating member has an unstressed external diameter greater than the unstressed internal diameter of the external mating member, and in which the external magnetic mating member is increased and not decreased in diameter due to magnetic forces.
Magnetic brakes and clutches of the prior art use solenoids or similar devices to actuate conventional mechanical brakes and clutches.
BRIEF DESCRIPTION OF THE INVENTION
Drum-type brakes and band-type clutches are frictional rotational energy transfer devices, and have common characteristics, in that an external circular annular mating member and a concentric circular internal mating member, with or without one or more intervening friction members, rotate without mutual friction, until the clutch or brake is actuated, when one or both mating members change diameter, so that rotational friction occurs between them, which transfers energy between mating members, and both mating members may be caused to rotate in the same direction at the same speed.
For convenience, in this disclosure, we designate as a brake, a device which transfers energy between the mating members when current flows in magnetizing windings, and designate as a clutch, a device which transfers energy between mating members when no current flows in magnetizing windings.
In this disclosure, an external annular magnetic mating member is caused to expand or contract in diameter, by magnetic forces generated by one or more conducting windings, carrying current, located around the annulus, and an internal annular magnetic mating member is caused to expand or contract in diameter by magnetic forces generated by one or more conducting windings, carrying current, located around the annulus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a simplified diagram of a magnetic clutch according to the invention.
FIG. 2 shows a simplified diagram of a magnetic brake according to the invention.
FIG. 3 shows a different winding arrangement for FIGS. 1 and 2.
FIG. 4 shows a simplified diagram of a frictional rotational torque transfer device with a conducting insulated winding on only the external mating member, according to the invention.
FIG. 5 shows a simplified diagram of a frictional rotational torque transfer device with a friction lining on only the external mating member, according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a simplified diagram of a magnetic clutch according to the invention. An external circular annular magnetic mating member 1, which is attached to an external mechanism, not shown, carries four alternate insulated conducting windings 7, 8, 9 and 10 of opposed directions of windings, in series, the number of turns wound in one direction being substantially equal to the number of turns wound in the opposed direction, with the external leads for the combined windings designated 11 and 12. A substantially non-magnetic friction lining 13 is internally attached to member 1, and is notched to permit the turns of windings 7, 8, 9, and 10 to pass around member 1.
Shaft 3 is concentric with member 1, and is concentric with and attached to internal circular annular magnetic mating member 2. Internal member 2 carries insulated conducting winding 4, with all turns in the same direction, and with external leads 14 and 15. Mating member 2 has externally attached friction lining 5. Friction linings 5 and 13 are strongly pressed together when no current flows in the windings, so that the clutch is engaged.
When a d-c voltage is applied to leads 11 and 12, external mating member 1 expands, due to the opposed magnetic fields, and when a d-c voltage is applied to leads 14 and 15, internal mating member 2 contracts, due to the aiding magnetic field, so that annular air gap 6 appears between friction linings 5 and 13, and the clutch is then disengaged.
It is apparent that one or both of friction linings 5 and 13 may be omitted, and that windings 7, 8, 9 and 10, or winding 4, may be omitted, and the mating member without windings need not be magnetic. If both mating members are magnetic and if both friction linings are omitted, a non-magnetic separator may take the place of one of the friction linings.
FIG. 2 shows a simplified diagram of a magnetic brake according to the invention. An external circular annular magnetic mating member 1, attached to an external mechanism not shown, carries insulated conducting winding 25, with all turns in the same direction, and with external leads 23 and 24. A non-magnetic friction lining 13 is internally attached to member 1, and is notched to permit the turns of winding 25 to pass around member 1.
Shaft 3 is concentric with, and is attached to, internal circular annular magnetic mating member 2. Internal member 2 carries four alternate insulated conducting windings 17, 18, 19 and 20, of opposite directions of winding, connected in series, with external leads 21 and 22 for the combined windings. Mating member 2 has externally attached friction lining 5. Friction lining 5 and 13 are separated by annular air space 6, when no current flows in the windings, and the brake is not actuated.
When a d-c voltage is applied to leads 21 and 22, internal mating member 2 expands, due to the opposed magnetic fields in member 2, and when a d-c voltage is applied to leads 23 and 24, external mating member 1 contracts, due to the aiding magnetic fields in member 1, so that annular air gap 6 is closed, and friction linings 5 and 13 press strongly against each other, so that the brake is actuated.
It is apparent that one or both of friction linings 5 and 13 may be omitted, and that windings 17, 18, 19 and 20, or winding 25, may be omitted, and the mating member without windings need not be magnetic. If both mating members are magnetic, and if both friction linings are omitted, a non-magnetic separator may take the place of the friction linings.
FIG. 3 shows another winding arrangement. In FIG. 1 and 2 the windings on the mating members are shown as toroidal in the drawings. It is evident that each of these windings, of one direction of winding, may consist of a concentrated multi-layer winding, with the same direction of winding as the toroidal winding of which it is the equivalent. This arrangement is shown in FIG. 3.
Circular annular magnetic mating number 30, with coils 31, 32, 33 and 34, connected in series to an external circuit by leads 35, 36, 37, 38 and 39, may be substitution for one or more of mating numbers 1 and 2 of FIG. 1, and 1 and 2 of FIG. 2, with their associated windings. Windings 31, 32, 33 and 34 are concentrated coils which may have one or more layers of turns, with all the turns of any one coil wound in the same direction. When series-aiding magnetic fields are required, as in internal member 2 of FIG. 1 and external member 1 of FIG. 2, coils 31 32, 33 and 34 are connected in series, so that their magnetic fields are in aiding relationship circumferentially. When adjacent opposed magnetic fields are required, as in external member 1 of FIG. 1 and internal member 2 of FIG. 2, coils 31, 32, 33 and 34 are connected in series, with polarities such that alternate coils generate opposed circumferential magnetic fields.
FIG. 4 shows a simplified diagram of a frictional rotational torque transfer device with a conducting insulated winding on only the external mating member.
In FIG. 4 an external annular magnetic mating member 1, which is attached to an external mechanism not shown, carries four insulated conducting windings 7, 8, 9 and 10, of alternately opposed directions of winding in series, the number of turns being wound in each direction being substantially equal, with external leads 11 and 12. A non-magnetic friction lining 13 is internally attached to member 1, and is notched to permit the passage of turns of windings 7, 8, 9 and 10.
Shaft 3 is concentric with member 1 and is concentric with and attached to internal circular annular mating member 40, which has externally attached friction lining 5. Friction members 5 and 13 are separated by annular air space 6 when energy is not transferred by friction between members 1 and 40, and air space 6 is reduced to zero when energy is transferred by friction.
FIG. 5 shows a simplified diagram of a frictional rotational torque transfer device with a friction lining on only the external mating member.
In FIG. 5 an external circular annular magnetic mating member 1 carries an insulated conducting winding 25, with all turns wound in the same direction, with leads 23 and 24. A friction lining 13 is attached internally to member 1 and is notched to pass the turns of winding 25.
Shaft 3 is concentric with, and is attached to, internal circular annular mating member 40. Friction member 13 and internal mating member 40 are separated by annular air gap 6 when energy is not being transferred by friction between members 1 and 40. Air gap 6 is reduced to zero when energy is being transferred by friction.
Since many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as being illustrative only and not limiting. | Drum-type brakes and band-type clutches which are activated by expansion or compression, or both, of one or more concentric magnetic members, with conducting windings carrying electric currents. Circular annular mating members carrying one or more conducting windings expand or contract in diameter, due to magnetic forces caused by currents in the winding or windings, and operate as a brake or a clutch. | 5 |
This application is a divisional application of Ser. No. 08/792,571, filed Jan. 30, 1997, now U.S. Pat. No. 5,861,033, which is a file wrapper continuation of Ser. No. 08/502,390 filed on Jul. 14, 1995, Abandoned, which in turn is a continuation application of Ser. No. 08/031,238 filed on Mar. 12, 1993 which is now U.S. Pat. No. 5,433,909 issued Jul. 18, 1995 which is a continuation in part of application Ser. No. 07/850,862, filed Mar. 13, 1992 now abandoned. The contents of all of the aforementioned application(s) are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
Many fluoropolymer materials, such as polytetrafluoroethylene (PTFE), are thermoplastic polymers. That is, they have the property of softening when heated and of hardening again when cooled. PTFE is generally produced in the form of white powder referred to as resin. It has a higher crystalline melting point (327° C.) and higher viscosity than other thermoplastic polymers, which makes it difficult to fabricate in the same manner as other plastics.
PTFE is a long chain polymer composed of CF 2 groups. The chain length determines molecular weight, while chain orientation dictates crystallinity. The molecular weight and crystallinity of a given resin prior to sintering are controlled by the polymerization process.
Currently, three different types of PTFE resins are available which are formed from two different polymerization processes. The three resins are granular polymer, aqueous dispersions, and coagulated dispersion products.
In the coagulated dispersion of PTFE resin, small diameter (0.1-0.2 micrometer) particles are coagulated under controlled conditions to yield agglomerates ranging in size from 400 to 500 micrometers in diameter. The morphological structure of these agglomerates can be considered as long chains of PTFE that are intermingled in a tangled network.
A known method of forming articles from fluoropolymer resins, such as PTFE, is to blend a resin with an organic lubricant and compress it under relatively low pressure into a preformed billet. Using a ram type extruder, the billet is then extruded through a die in a desired cross-section. Next, the lubricant is removed from the extruded billet by drying or other extraction method. The dried extruded material (extrudate), is then rapidly stretched and/or expanded at elevated temperatures. In the case of PTFE, this results in the material taking on a microstructure characterized by elongated nodes interconnected by fibrils. Typically, the nodes are oriented with their elongated axis perpendicular to the direction of stretch.
After stretching, the porous extrudate is sintered by heating it to a temperature above its crystalline melting point while it is maintained in its stretched condition. This can be considered as an amorphous locking process for permanently "locking-in" the microstructure in its expanded or stretched configuration.
It has been found that the effect caused by stretching PTFE is dependent on extrudate strength, stretch temperature, and stretch rate. According to U.S. Pat. No. 3,953,566 of W. L. Gore, products expanded at high rates of stretch have a more homogenous structure and possess much greater strength. Extrudate strength is more generally a function of the molecular weight and degree of crystallinity of the starting resin and extrusion conditions such as extrusion pressure, lubricant level, and reduction ratio. These parameters also control the degree of alignment that results from extrusion. The degree of alignment, in turn, affects one's ability to homogeneously stretch the extrudate.
Molecular weight and crystallinity affect the stretch characteristics, sinter profile and ultimately the final properties of the processed material. For the initial stages of fabrication, most PTFE fine powders used for ram extrusion and expansion processing are highly crystalline (>90%). as determined by IR spectroscopy, but their molecular weights may differ.
Low molecular weight materials tend to crystallize quickly and become highly crystalline and very brittle. In addition, the intermolecular forces between difluoromethylene groups are very low. Thus, in order to achieve adequate strength, one needs either very high molecular weight, highly crystalline material or one needs some way to disrupt the crystalline order. With a homopolymer, the best way to inhibit crystallization is to increase the viscosity of the molten material to very high values by selecting a polymer with very high molecular weight. In fact, PTFE coagulated dispersion resins that have very high molecular weights with molecular weight distributions have been developed for expanded PTFE processes.
In line with these considerations, the primary function of the "sintering" step is to heat the polymer above its crystalline melt point so that it can be reformed upon cooling to a low enough crystalline content to achieve the sort of mechanical properties required for the current application. To maintain a low crystalline content in the final product, the melt viscosity, corresponding to the molecular weight of the polymer, must be very high.
Most known methods for processing PTFE describe unilateral stretching techniques and stress the importance of stretching the fluoropolymer at rapid rates. For example, U.S. Pat. Nos. 3,953,566 and 4,187,390 issued to Gore state that while there is a maximum rate of expansion beyond which fracture of the material occurs, the minimum rate of expansion is of much more practical significance. Indeed, the patents state that at high temperatures within the preferred range for stretching (35° C.-327° C.) only the lower limit of expansion rate has been detected. The patents estimate this rate to be ten percent of the initial length of the starting material per second. The patents go on to note that the lower limit of expansion rates interact with temperature in a roughly logarithmic fashion so that at higher temperatures within the preferred stretching range, higher minimum expansion rates are required.
U.S. Pat. No. 4,973,609 to Browne describes another method for producing porous PTFE products by stretching at a rate of 10% per second. The patent also states that a differential structure is obtained by using an alloy of two different fluoropolymer resins which are characterized by significantly different stretch characteristics. The resins have different molecular weights and/or crystallinities. Accordingly, the final physical properties, such as strength, of PTFE articles formed in such a way are affected by the different molecular weights and/or crystallinities of the starting resins.
U.S. Pat. Nos. 4,208,745 and 4,713,070 also describe methods for producing porous PTFE products having a variable structure. The processes utilize a sintering step having a differential sintering profile. That is, one surface of an expanded PTFE article is sintered at a temperature which is higher than the sintering temperature of another surface. This results in fibrils being broken and provides an inherently weak material.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a process for producing a shaped porous article which is more truly semi-permeable than known articles formed of fluoropolymer materials. It is another object of the invention to provide such a process in which a fluoropolymer extrudate can be homogeneously stretched independently of rate. Still another object is to provide a porous article. Yet another object of the invention is to provide a porous article having a porosity which is variable in the direction of the article's cross-section.
These and other objects are achieved by the present invention which in one aspect features a process for producing a porous article. The process includes the steps of providing an extrudate of a fluoropolymer material which is capable of being stretched and bilaterally stretching the extrudate along its longitudinal axis. Conditions are maintained during stretching sufficient to yield an article which is substantially uniformly stretched over a major portion of its length. These conditions include stretch rate, ratio, and temperature.
The stretched extrudate has a microstructure which is characterized by elongate nodes which are connected by fibrils. This microstructure is locked in by sintering the stretched extrudate while maintaining it in its stretched state.
An important feature of the invention is that the fluoropolymer extrudate is bilaterally stretched. That is, in accordance with the invention both ends of the extrudate are displaced along the extrudate's longitudinal axis away from a central portion of the extrudate. It has been found that this stretching method provides significant advantages over known stretching methods wherein one end of an extrudate is held stationary while only the other end is displaced.
In various embodiments of this aspect of the invention the bilateral stretching is carried out at rates not greater than ten percent per second. Indeed, it has been found that stretching at rates slower than even one percent per second provides a material having an extremely desirable microstructure of nodes and fibrils, the nodes being significantly larger than nodes resulting from known processes of rapidly stretching single-resin extrudates unilaterally.
In carrying out the stretching step in accordance with the process of the invention, the ends of the extrudate can be displaced either simultaneously or sequentially. For example, in one embodiment of the invention, a first end of the extrudate is displaced to a stretch ratio of not greater than two to one. That first end is then held stationary while the second end of the extrudate is displaced in the opposite direction to again result in a stretch ratio of not greater than two to one. Restricting the individual stretches to stretch ratios of not greater than two to one ensures a substantially homogeneous microstructure along a major portion of the length of the extrudate.
In another aspect, the invention features a process for producing a porous tube of polytetrafluoroethylene including the step of providing a preformed billet of a mixture of a polytetrafluoroethylene resin and a lubricant. As with the above-described aspect of the invention, the billet is extruded, the extrudate is then dried, and bilaterally stretched along its longitudinal axis under conditions sufficient to yield a tube having a substantially homogenous microstructure over a major portion of its length. The stretched tube is then sintered while being maintained in its stretched state to produce the porous tube.
In one embodiment of this aspect of the invention, the preformed billet is formed to have a lubricant level which selectively varies in the direction of the billet's cross-section. That is, for example, the billet might have a lubricant level of fifteen percent by weight at its inner and outer surfaces and a lubricant level of approximately twenty percent at a radial position between its inner and outer surfaces. When extruded and stretched, such a billet results in a porous tube having a microstructure which varies in a controlled fashion in the direction of the tube's cross-section. This phenomenon and its advantages are described below in greater detail.
Accordingly, in the various embodiments of this aspect of the invention, a porous article having a desired microstructure is provided by controlling the billet lubricant level, the billet reduction ratio, and bilateral stretching conditions such as stretch rate and ratio. These steps avoid the problems such as weak material which are associated with known resin-blending and varied-profile sintering techniques.
In still another aspect, the invention features a tube formed of an expanded porous fluoropolymer material. The material has a microstructure characterized by ring shaped nodes interconnected by fibrils. An important feature of this aspect of the invention is that substantially all of the nodes each circumscribes, at least in part, the longitudinal axis of the tube and extends from the inner to the outer surface of the tube wall, thereby creating between the nodes continuous through-pores from one surface to the opposite surface.
In accordance with yet another aspect, the invention features a tube formed of porous fluoropolymer material characterized by a structure of nodes and fibrils wherein the nodes are radially oriented and the fibrils extend substantially parallel to the axis of the tube between successive nodes, the nodes and fibrils forming pores having radially tapering size distribution conducive to tissue through-growth.
These and other features of the invention will be more fully appreciated by reference to the following detailed description which is to be read in conjunction with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a porous article formed in accordance with the teachings of the present invention,
FIG. 2 is a scanning electron microscopic view of a longitudinal cross-section of a porous article in accordance with the invention,
FIG. 3 is a scanning electron microscopic view of a radial cross-section of a porous article in accordance with the invention,
FIG. 4 is a schematic depiction of a billet suitable for extrusion in accordance with the invention,
FIG. 5A is a scanning electron microscope longitudinal cross-section view of another porous article in accordance with the invention,
FIG. 5B is a scanning electron microscope view of the inner surface of the porous article shown in FIG. 5A,
FIG. 5C is a scanning electron microscope view of the outer surface of the porous article shown in FIG. 5A,
FIG. 6 is a schematic longitudinal cross-section view of still another porous article in accordance with the invention,
FIG. 7 is a schematic representation of a tubular structure according to a presently preferred embodiment of the invention,
FIG. 7A is a photomicrograph of a radial section through the structure of FIG. 7,
FIG. 7B is a photomicrography of a tangent section taken at the interior of the structure of FIG. 7,
FIG. 7C is a photomicrograph of a tangent section taken of the exterior of the structure of FIG. 7,
FIG. 8A schematically illustrates a tube preform with layered material of radially decreasing lube level, and
FIGS. 8B and 8C are photomicrographs of tangential sections of a tube formed from the preform of FIG. 8A, taken in the regions corresponding to B and C, respectively, of FIG. 7.
DETAILED DESCRIPTION
As stated above, in one aspect the invention features a process for producing a shaped porous article. A significant feature of the process is that an article having a homogeneous microstructure is formed independently of the rate at which it is stretched.
By homogenous microstructure, in this patent application, it is intended to convey first that the microstructure of the article, including relatively dense nodes separated by relatively light connecting fibrils, is relatively uniform along at least one dimension, e.g., the length of the article, although as will be explained below, aspects of microstructure may be, and preferably are, intentionally varied in another direction, e.g., in cross-section of the article.
Various fluoropolymer resins are suitable for use in the present invention. For example, polytetrafluoroethylene or copolymers of tetrafluoroethylene with other monomers may be used. Such monomers may be ethylene, chlorotrifluoroethylene, perfluoroalkoxytetrafluoroethylene, or fluorinated propylenes such as hexafluoropropylene. In particular, however, polytetrafluoroethylene (PTFE) works well. Accordingly, while the inventive process can be utilized to produce porous articles formed of various fluoropolymer materials, the following description pertains specifically to the formation of an article from PTFE resin.
For purposes of the present invention, all fluoropolymers that require a lubricant/extrusion aid and are capable of being expanded can be used. However, it is preferred to use highly crystalline, high molecular weight resins to achieve maximum strength. When PTFE is used, resin of a molecular weight between 5,000,000 and 70,000,000 is suitable.
It should be noted, however, PTFE does not dissolve in any common solvent; therefore its molecular weight cannot be measured by the usual methods. According to the Encyclopedia of Polymer Science and Engineering (Wiley and Sons, 1989), though, the following relationship has been established between number-average molecular weight (Mn), for molecular weights between 5.2×10 5 and 4.5×10 7 , and the heat of crystallization (ΔHc) in Joules/gram (calories/gram).
Mn=(2.1×10.sup.10)×ΔHc.sup.-5.16
Accordingly, by determining the heat of crystallization of a given PTFE resin, a number average molecular weight of the resin is determined using this relationship.
As with known methods of processing PTFE, the invention utilizes a preformed billet which comprises a PTFE resin mixed with an organic lubricant. Various lubricants are suitable such as naphtha, ISOPAR-G and ISOPAR-H available from Exxon Corporation. Low odor paraffin solvents can be used as well. The blended resin is compressed at low pressure (less than 1000 PSI) into a tubular billet of approximately one third of the resin's original volume. Billet forming processes are generally known in the art.
As discussed above, extrusion conditions have a significant effect on the resulting extrudate's reaction to being stretched. In particular, once a resin of a given molecular weight and crystallinity has been selected, extrudate qualities are controlled by the level of lubricant mixed with the resin to form the billet, the reduction ratio at which the billet is extruded and the extrusion pressure. These are believed to influence the micromechanical properties of the extruded article because these parameters affect the degree to which the molecular chains of PTFE align themselves during extrusion.
The process of the invention is most effective when using preformed billets ranging in lubricant level from between 8 to 25 percent by weight to produce an extrudate well adapted for the inventive stretching process.
When PTFE extrudate is subjected to an external tensile force, such as during stretching, the intermingled network of PTFE particles separate. Accordingly, the force required to separate these particles, and hence stretch the extrudate, is dependent upon the degree of intermingling of the PTFE particles. The longer the polymer chains (higher molecular weight), the greater the amount of intermingling that will occur and, therefore, the greater the force that will be required to separate the coagulated dispersion particles.
Two other extrusion parameters having an effect on a resulting extrudate's reaction to stretching are reduction ratio and extrusion pressure. The range of suitable reduction ratios is bounded at its lower end by the minimum reduction ratio permissible which provides an extrudate of sufficient strength so as not break during stretching. At its upper limit, the range of suitable reduction ratios is bounded by the maximum ratio permissible which provides an extrudate that is amenable to being homogeneously stretched. Accordingly, experimentation has shown that for purposes of the present invention the preformed billet should be extruded to a reduction ratio of between approximately 50:1 and 600:1. A preferred reduction ratio is between approximately 200:1 and 400:1.
Reduction ratio and stretch characteristics are interrelated since the force required to deform a PTFE extrudate and form fibrils from the nodes is related to how the material was aligned (packing density) during extrusion. Fibrils are not formed as easily from nodes with high reduction ratio extrudates as they are with low reduction ratio extrudates. This is believed to be because internal forces are much higher in high reduction ratio extrudates.
The third extrusion parameter which has a significant effect on the resulting extrudate's properties upon being stretched is extrusion pressure. While extrusion pressure is, to a certain extent, related to reduction ratio, by varying lubricant level, extrusion pressure can be varied independently of reduction ratio. While measured extrusion pressure will vary depending upon the type of extrusion equipment being used, the range of suitable extrusion pressures to practice the present invention will be apparent to those skilled in the art. For example, pressures between approximately 6000 PSI and approximately 10,000 PSI have been used successfully for the practice of the invention.
Once an extrudate has been produced according to the above described parameters, in accordance with the inventive process it is stretched under conditions sufficient to yield an article that is uniform over a major portion of its length. Stretching processes are characterized in terms of stretch rate and stretch ratio. Stretch rate refers to the percentage change in length of the extrudate per unit time. In the case of a fifty centimeter long extruded tube, for example, stretching five centimeters per second results in a stretch rate of ten percent per second. The percentage change is calculated with reference to the initial length of the extrudate.
Stretch ratio, on the other hand, is not time dependent but merely refers to the ratio of the final length of the stretched extrudate to that of the initial length of the unstretched extrudate. Accordingly, stretching a fifty centimeter long extruded tube to one hundred centimeters, results in a stretch ratio of 2:1 regardless of the duration of the stretch.
With this in mind, it is an important feature of the invention that extruded materials are stretched to form porous articles independently of stretch rate. In certain instances the process is dependent on stretch ratio. As stated above, known methods for processing fluoropolymer materials teach that stretching must be carried out at a rate generally exceeding approximately ten percent per second. In accordance with the invention, however, homogeneous articles are produced at stretch rates not greater than approximately ten percent per second. Indeed, the preferred rate of stretching ranges from approximately 0.5 percent per second to approximately 10 percent per second.
To stretch an extrudate, the extrudate must be placed in tension. This is done by applying opposed forces to the ends of the extrudate. The level of force applied to the extrudate, and hence the rate at which the extrudate stretches, determines how the above-described intermingled network of PTFE particles unravels. In known methods for stretching PTFE, force is applied to place the extrudate in tension by displacing one end of the extrudate with respect to the other end. At stretch rates lower than ten percent per second, this method of stretching cannot uniformly stretch the extrudate to greater than a 2:1 ratio. To the contrary, at greater ratios the material stretches preferentially at its moving end. The fixed end of the material, on the other hand, experiences significantly less stretching.
In accordance with the invention, on the other hand, bilateral stretching results in more even force distribution along the length of the extrudate and produces a more homogeneously stretched material. It has been found that stretching bilaterally, that is, displacing both ends of the extrudate away from the middle of the extrudate, provides a material that is homogeneously stretched over the majority of its length independent of the stretch rate.
After the extrudate has been bilaterally stretched it is sintered by heating it above its crystalline melting point under tension. As discussed above, this locks in the microstructure of the material and completes the process of producing the porous article.
FIG. 1 is a schematic representation of a porous tube 10 formed by the above described bilateral stretching process. For purposes of description, the microstructure of the tube 10 has been exaggerated. Accordingly, while the dimensions of the microstructure are enlarged, the general character of the illustrated microstructure is representative of that microstructure prevailing in an article formed by the inventive process.
The tube 10 includes a microstructure characterized by elongate nodes 12 interconnected by fibrils 14. A significant feature of the tube 10 is that the nodes 12 are ring-shaped to form, in effect, a series of washer-type, or plate-like solid bodies circumscribing the tube's longitudinal axis L. The nodes 12 are oriented generally radially, i.e., perpendicularly to the axis of stretching, represented by arrows T which is coincident with the longitudinal axis L.
Another significant feature of the tube's microstructure is that substantially all of the nodes 12 extend along a transverse axis t from an inner surface 16 of the tube to an outer surface 18 of the tube. This dimension of the nodes 12 along the inside-to-outside direction is significantly larger than the corresponding dimension of nodes formed by conventional single-resin fluoropolymer processing methods. Such nodes are randomly arranged and may be characterized by a transverse axis which is generally oriented perpendicularly to the axis of stretch. Notably, however, the nodes of these known structures are considerably shorter and smaller than nodes produced in accordance with the present invention. Indeed, the above-referenced U.S. patents to Gore note that nodes formed by that known technique generally range in size from smaller than one micron to approximately 400 microns.
Unlike the short, randomly stacked nodes and microfibrillar spaces formed by conventional single-resin fluoropolymer stretch or expansion processing, the method of the present invention provides a microporous structure having microfibrillar spaces which define through-pores or channels extending entirely from the inner to the outer wall of the expanded extrudate. These through-pores are perpendicularly oriented internodal spaces which traverse from one surface to another.
As discussed below in greater detail, by varying lubricant levels such internodal through-pores are preferentially altered in accordance with the present invention such that the surface pore on one surface is made to be larger or smaller than the surface pore on the opposing surface.
A longitudinal cross-section view of a tubular article formed by the process of the invention is shown in FIG. 2. There, it can be seen that the present invention produces an article having a microstructure characterized by elongate nodes which are substantially larger than the nodes of materials produced by known single-resin forming methods. Indeed, the nodes shown in FIG. 2 consistently range in size from approximately 500 microns to approximately 900 microns. Substantially all of the nodes of the article shown in FIG. 2 extend from the inner surface of the tubular article to the outer surface of the tubular article, thereby creating through-pores substantially all of which traverse from one surface of the article to the other.
FIG. 3 is a radial cross-section view of the tubular article shown in FIG. 2. There it can be seen that while the nodes are generally oriented perpendicularly to the axis of stretch, as represented in FIG. 1, they are not perfectly flat and, therefore, a radial cross-section cuts through many nodes. Accordingly, while the schematic representation in FIG. 1 is useful for purposes of explanation, the scanning electron microscope photographs in FIGS. 2 and 3 are more accurate depictions of the microstructure of a product produced by the inventive process.
Products provided by the invention are suitable for a wide range of biological applications such as for vessel implants or organ wall grafts. In particular, as described below, vascular grafts formed by the process of the invention enjoy various advantages. Indeed, the processes of the invention are well suited for the formation of the various biological devices described in the following commonly assigned and co-pending United States Patent Applications: U.S. Ser. No. 760,753 (abandoned in favor of Filed wrapper continuation Ser. No. 08/109,103 now U.S. Pat. No. 5,411,550) for "IMPLANTABLE PROSTHETIC DEVICE FOR THE DELIVERY OF A BIOACTIVE MATERIAL"; U.S. Ser. No. 760,716, now U.S. Pat. No. 5,197,976 for "MANUALLY SEPARABLE MULTI-LUMEN VASCULAR GRAFT"; U.S. Ser. No. 760,728 (abandoned, refiled as file wrapper continuation Ser. No. 08/029,982 now U.S. Pat. No. 5,320,100) for "IMPLANTABLE PROSTHETIC DEVICE HAVING INTEGRAL PATENCY DIAGNOSTIC INDICIA"; U.S. Ser. No. 760,717 (abandoned, refiled as file wrapper continuation Ser. No. 08/029,990, now U.S. Pat. No. 5,370,681) for "POLYLUMENAL IMPLANTABLE ORGAN"; and U.S. Ser. No. 760,718, now U.S. Pat. No. 5,192,310, for "SELF-SEALING IMPLANTABLE VASCULAR GRAFT" all of which were filed Sep. 16, 1991. The specifications of these applications for patent are hereby incorporated herein by reference.
As stated, several structural, clinical and biological advantages accrue from the microstructure engendered by the inventive process. For example, as discussed below in greater detail with regard to the various examples, larger node size provides a structure having a significantly improved radial tensile strength. Also, tubes formed by the inventive process have improved burst pressure and suture strength characteristics. The flat ring-like node structure imparts significantly more flexibility, without kinking, than conventional fluoropolymer processes, in addition to providing superior resistance to radial twist compression (colloquially known as "torque twist"). The tubular article formed by the process of the invention allows a significant degree of bending or radial twist, before experiencing lumen collapse or kinking, unlike conventional fluoropolymer articles which exhibit significantly less resistance to "torque twist" or "bending." Conventional articles, therefore, kink under smaller stress loads than do the articles of the current invention.
Additionally, the method of the current invention produces articles which exhibit significantly more resistant to compression than conventionally processed articles. This provides more resistance to luminal collapse under equivalent stress loads. The articles provided by the invention also exhibit increased flexibility for enhanced drapability, or ability to bend more readily, without restricting luminal cross-sectional area, thereby improving ease of handling during surgery, while not increasing stress on the points of attachment and fixation. The ring like nodal architecture of the invention also produces tubular structures with significantly more resistance to tearing or splitting in the horizontal direction, as compared to conventional non-reinforced fluoropolymer tubular articles.
For experimentation, an extrudate was prepared by blending PTFE resin (Fluon CD-123 obtained from ICI Americas) with "ISOPAR-H" odorless solvent (produced by Exxon Corporation) used as an extrusion aid at a level of 150 cc of solvent per pound of resin. The blend was compressed into a tubular billet, heated to 300° C., and extruded into a 6 mm I.D. by 7 mm O.D. tube in a ram extruder having a reduction ratio of about 149:1 in cross-sectional area from billet to the extruded tube. The volatile extrusion aid was removed by drying in a heated oven prior to stretching.
To demonstrate the advantages of bilateral stretching in accordance with the invention, samples of the tubular extrudate were then stretched various ways as discussed below.
Method 1
An apparatus was developed that allowed samples of the tubular extrudate to be stretched at controlled rates and temperatures. The apparatus consisted of two clamps for holding the tube, one clamp held fixed within the oven and another clamp attached to a chain drive coupled to a variable speed motor. The tube was stretched an amount equal to 50% of its original length at a rate of approximately 10% per second. The fixed and moveable ends were then inverted and the stretching step repeated. The stretch and inversion steps were repeated until the extrudate sample had been stretched to a final stretch ratio of three to one. The oven temperature was then raised to 370° C. for ten minutes while the samples were held clamped.
Method 2
An apparatus was developed that allowed both ends of the extrudate to be displaced simultaneously, at a controlled temperature and rate. The apparatus included two clamps independently mounted to two slide drive systems. Following mounting to the stretch apparatus, both sides of the sample were displaced simultaneously at equal speeds in opposite directions for a selected distance. The applied stretch rate using the combined displacements rates from each side was calculated to be approximately 10% per second. The final stretch ratio was approximately three to one.
Method 3
The apparatus described in Method 2 was used to displace each end of the extrudate sequentially. That is, first one end of the extrudate was held fixed while the other was displaced a given distance at a constant speed, then, without inverting the sample, the previously displaced end was held stationary while the formerly stationary end was displaced the same distance at the same speed. Again, the sample was stretched at a rate of approximately 10% per second to a final ratio of approximately three to one.
Samples produced by the above described methods were then tested along with commercially available PTFE tubes produced by conventional, unilateral stretch techniques, the results appearing below.
______________________________________SAMPLE A B C D E F______________________________________Conventional 3060 640 7.9 55 2.2 800 Method 1 2660 803 2.9 90 0.5 1462 Method 2 2720 833 2.8 95 0.5 1382 Method 3 2400 845 2.8 95 0.5 1861______________________________________
Where A is longitudinal tensile strength (pounds per square inch);
where B is radial tensile strength (pounds per square inch);
where C is water entry level (pounds per square inch);
where D is radial burst pressure (pounds per square inch);
where E is ethanol bubble point (pounds per square inch); and
where F is suture strength (in grams) for a 2 mm bite.
Further, tubular extrudate samples as produced above were bilaterally stretched, displacing both ends simultaneously, at other stretch rates. Again, the stretch rates were calculated by combining the displacement rates of both ends of the extrudate. Tests performed on samples produced in this manner yielded the results detailed below.
______________________________________ A B C D F______________________________________10%/sec 2232 780 2.8 95 1838 5%/sec 2144 933 2.4 90 1657 0.5%/sec 2372 953 2.1 105 1612______________________________________
The data clearly indicate that enhanced radial strength and suture strength along with a corresponding decrease in Water Entry Pressure and Ethanol Bubble Point, result from the inventive bilateral stretching process.
For purposes of evaluating homogeneity, additional tubular extrudate samples were marked at 1/2" spaced intervals using a permanent marker. The samples were mounted and stretched either unilaterally with one end held fixed throughout the stretching process or bilaterally in which both ends were displaced simultaneously. After stretching at rates equal to or lower than 10% per second the samples were sintered and analyzed by measuring the distance between the marks along the sample lengths. This distance, divided by the original half-inch spacing yields a local measure of the expansion ratio. The results detailed below indicate that at low rates of stretch bilateral stretching produces a structure which is more uniform than unilaterally stretched products. That is, with the bilaterally stretched samples, each half inch segment stretched an amount comparable to all segments through the length of the sample. Each unilaterally stretched sample, on the other hand, stretched preferentially at its moving end, often by a factor three to five times greater than that of its restrained end.
______________________________________BILATERAL STRETCHING FINAL STRETCH LENGTH IN INCHES OF EACH SEGMENT 10%/SEC 5%/SECORIGINAL DISTANCE FROM MIDDLE 3:1 4:1 3:1 4:1 (INCHES) RATIO RATIO RATIO RATIO______________________________________2.0 1.375 1.75 1.25 1.75 1.5 1.375 1.875 1.5 2.0 1.0 1.375 1.875 1.375 2.0 0.5 1.5 1.875 1.5 1.875 0.5 1.5 1.75 1.5 1.875 1.0 1.5 2.0 1.5 2.0 1.5 1.5 2.0 1.375 1.875 2.0 1.5 1.75 1.5 2.0______________________________________
It can be seen that at a rate of 10% per second, bilaterally stretching an extrudate to a ratio of 3:1 in accordance with the invention yields an achieved expansion factor that varies by under 10% along the length of the stretched extrudate. Bilaterally stretching to a 4:1 ratio at this rate yields a variation of less than 8%.
Bilaterally stretching at 5% per second yields similar uniformities in achieved expansion factor. Moreover, such variations as there are, appear to be distributed in a more spatially uniform way.
______________________________________UNILATERAL STRETCHING FINAL STRETCH LENGTH IN INCHES OF EACH SEGMENT 10%/SEC 5%/SEC 0.5%/SECORIGINAL DISTANCE FROM FIXED END 3:1 4:1 3:1 4:1 3:1 4:1 (INCHES) RATIO RATIO RATIO RATIO RATIO RATIO______________________________________0.5 1.25 1.375 1.0 0.5 0.875 0.75 1.0 1.125 1.5 1.0 0.5 0.875 0.75 1.5 1.0 1.75 1.0 0.875 0.875 0.75 2.0 1.125 1.875 1.125 1.5 1.0 1.0 2.5 1.375 2.25 1.25 1.875 1.375 1.75 3.0 1.625 2.375 1.5 3.5 1.875 3.5 3.5 2.125 2.75 2.125 4.0 2.25 4.0 4.0 2.875 2.75 2.375 4.0 2.625 4.25______________________________________
These results show that with unilateral stretching at the above-noted rates and ratios, a far greater variation in achieved expansion results. In particular, the results show that at these rates and ratios, a unilaterally stretched sample stretches preferentially at its moving end.
In another embodiment of the invention, a porous article is formed utilizing a preformed billet such as billet 50 shown in FIG. 4. Billet 50 includes radial inner portion 52 and radial outer portion 54. A significant feature of billet 50 is that while radial portions 52 and 54 comprise the same resin, different lubricant properties prevail in the portions. For example, different types of lubricant, different molecular weight lubricants of the same type, lubricants of different viscosity, or a single lubricant but at different relative proportions may be used.
The formation of layered preform billets is generally known in the art. For example, various known techniques have been used to produce extrudates having a conductive layer in electronic applications or a colored layer in general tubing applications. U.S. Pat. No. 4,973,609 assigned to Browne describes a layering technique using different resins.
In accordance with this aspect of the present invention, the microstructure of an extruded and expanded PTFE article is controlled using a single resin with a varying lube characteristic, preferably the lube level, through the preform billet. For instance, the sample shown in FIGS. 5A through 5C was produced using a single PTFE resin that was preformed in a layered fashion at two different lube levels across its cross-section and processed according to the above described bilateral stretching process.
FIG. 5A is a longitudinal cross-section view of a wall 60 of a tubular article formed utilizing the billet 50 in accordance with the above-described inventive process. As can be seen in the Figure, the material forming the wall 60 is characterized by a microstructure of large nodes 62A and small nodes 62B interconnected by fibrils 64. This results due to the inner radial portion 52 of billet 50 having a lower lubricant level than the outer radial portion 54. That is, lower lubricant levels result in smaller, more closely spaced nodes.
Several advantages accrue from the structure of wall 60. For example, by forming a tube having porosity at an inner surface 66 (FIG. 5B) which is smaller than the porosity at an outer surface 68 (FIG. 5C), a vascular graft is provided which defines an efficient flow channel at its inner surface while fostering improved cellular ingrowth at its outer surface.
It should be understood that in addition to the illustrated embodiment, billets can be formed in accordance with the present invention having lubricant properties which vary in a selected pattern through the cross-section to achieve desired pore or channel distribution. For example, by forming a tubular billet which has a lubricant level which is different at a radial position of the cross-section from the lubricant level at another position, e.g., the inner or outer surfaces of the cross-section, and by carefully extruding a preform from the billet, a unique product is formed. For example, a tubular article having a wall 70, such as shown in FIG. 6, can be formed by this method. Note that the wall 70 has relatively large pores at its inner and outer surfaces 76 and 78 but includes a barrier region 80 of smaller pores between the inner and outer surfaces. Such a structure used as an implant or vascular graft is expected to promote cellular ingrowth from both sides of the wall 70 while preventing cellular growth completely through the wall.
From the fact that stretching of the extrudate yields an article with pore structure corresponding to the lube distribution of the preform, it appears that flow in the long tapered extrusion head is highly laminar. Such flow can result in a uniformity of PTFE molecular orientation. Applicant expects this property to result in an extrudate that, after sintering (but even without any stretching), will have high tensile strength, as compared to conventionally extruded materials. Accordingly, it is also comprehended within the scope of the present invention to extrude an extrudate from a billet of varying lube level or other characteristic, and, without stretching the extrudate, sinter it to fix its dimensions.
For biological applications, the unique through-pore orientation created by the individual nodal spaces is exploited, for example, to either increase or decrease the migration of certain cellular and or biological materials directly into or onto the inventive tubular structure. This results in improved biocompatibility. For example, it is well documented that specific cell types penetrate, grow into, or onto porous fluoropolymer structures. By providing a matrix of large, oriented nodes to present non-tortuous pathways, full cellular penetration is possible, without "dead ended" channels. This offers a significantly improved cellular environment, for example, to promote the growth of morphologically complete capillaries. The provision of large-entry channels with a taper offers similar advantages, with the added feature of precisely limiting the depth of tissue penetration. Hence the hybrid nodal structure design of this invention offers many structural, physical and biological characteristics not found with other, well documented pure fluoropolymer, composite or coated tubular articles.
In accordance with the invention, therefore, methods and materials are provided for the formation of biological implants having enhanced structures and tissue support features. Both organ wall grafts and vessel implants can be formed by practice of the invention. Representative methods of fabricating tube structures with taper nodal geometry will now be briefly described.
Method 4
PTFE resin identified as Fluon CD-123 obtained from ICI Americas was blended in two separate containers with 98 cc and 150 cc, respectively, per pound of resin, of an odorless mineral solvent, identified as Isopar-H produced by Exxon Corporation. The solvent serves as a lubricant for extrusion of the resin, in a manner well known in the art. The two resin/lube mixes were then separately poured into a preforming cylinder in concentric layers to form a billet or preform 50 as shown in FIG. 4. Inner layer 52 of extrusion preform 50 contained the lower lube level (98 cc lube/lb) resin. Outer layer 54 of preform 50 contained the higher lube level (150 cc/lb) resin. A core-rod cylinder was fitted over the core rod of the preforming cylinder to separate the layers during pouring. The cylinder was removed after pouring was completed, and the extrusion preform, or billet, was formed by compacting the layered mass under a compaction pressure of 600 psi, to produce a dense preform billet having a concentric stepped concentration of lube level.
The preform billet was then inserted into a ram extruder and extruded into a 4 mm I.D./5.3 mm O.D. tube, the ram extruder having a reduction ratio of 350:1 in cross-sectional area from preform to extruded tube. Fifteen inch samples were cut from the tubular extrudate and allowed to bake at 300° C. for five minutes prior to stretching in order to remove the lubricant, which was a volatile extrusion aid. The samples were then stretched at 300° C. at a rate of 0.5% per second to a length of 45 inches. Sintering was effected by clamping the tube ends and heating the restrained samples to a temperature of 370° C. for four minutes.
FIG. 7 indicates in schema a tube structure 150 formed in this fashion having interior surface 152 and exterior surface 154, with the section lines A, B, and C identifying radial and inside and outside sections for which electron micrographs of a prototype tube are discussed below.
Indicated sample sections of the expanded tube were then prepared and subjected to electron micrography, as shown in FIGS. 7A-7C.
As best seen in the radial section, FIG. 7A, the inner surface 152 of a tube prepared in this manner has a more frequent node structure than the outer surface, with nodes spaced almost twice as frequently along the tube axis as at the outer surface 154. Fibril length is therefore necessarily shorter, but both inner and outer regions have full, densely-arrayed fibrils with none of the coalescence that characterizes the differential-heating approach to node tailoring of the prior art. Moreover, the diameter of the fibrils is essentially the same at the inside and outside regions.
As seen in FIG. 7C, the node-fibril structure in the radially outer portion of the tube is characterized by large intact node bodies, spaced 40-80 micrometers apart, whereas that of the radially inner portion has a node spacing in the range of 25-50 micrometers (FIG. 7B). The overall form of the nodes is that of flat plates oriented perpendicular to the tube axis, and extending in partial or complete annuli about the central lumen of the tube. The inside edges of the nodes may be seen to be somewhat fragmented or frayed in appearance, while still preserving the overall plate-like form and radial orientation of the outer portion, despite their closer spacing.
The resulting structure therefore has through-pores extending substantially continuously from the inside to the outside. In addition, applicant has found this material to have a strength comparable to conventional stretched PTFE products fabricated using much higher stretch rates.
Method 5
PTFE resin as used in Method 4 was blended in two separate containers with 104 cc and 150 cc, respectively, of Isopar-H per pound of resin. The two resin/lube mixes were then separately poured into a preforming cylinder in concentric layers as shown in FIG. 8A with the inner layer 52' of extrusion preform 50' comprised of higher lube level (150 cc lube/lb) resin and the outer layer 54' of preform 50' comprised of lower lube level (104 cc/lb) resin. As before, a core-rod cylinder was fitted over the core rod of the preforming cylinder to separate the layers during pouring and was removed after pouring was completed. An extrusion preform was then formed by compacting the layers under a pressure of 600 psi.
The preform was then extruded into a 4 mm I.D./5.6 mm O.D. tube in a ram extruder having a reduction ratio of 220:1 in cross-sectional area from preform to extruded tube. Fifteen inch samples were cut from the tubular extrudate and allowed to bake at 300° C. for five minutes prior to stretching in order to remove the extrusion lubricant. The samples were then stretched at a rate of 2.5% per second to a length of 45 inches, followed by sintering by heating the restrained samples to a temperature of 370° C. for four minutes.
As shown in FIG. 8B, a tangential section at the inner region of a tube so formed has a nodal structure of relatively large, ring-like sheets oriented perpendicular to the tube axis. As indicated in FIG. 8C, the nodal structure at the outer region retains the same orientation, but becomes more closely spaced. Thus, the relative porosity varies, from the inside to the outside, in a sense opposite to that of the tube structure produced by Method 4.
It will be appreciated by those skilled in the art that in each of the foregoing embodiments the structure of nodes and fibrils results in a pore structure wherein interstitial spaces of tapering aspect extend entirely, or substantially entirely through the wall of the tube.
As described above, extrusion from a billet formed with varying levels of lubricant produces a preform, and after stretching results in an article, having a pore structure that varies. Applicant expects a similar effect to result from use of a billet wherein, rather than varying the level of lubricant, one position (e.g., inside, or outside) is formed using a lubricant of different density or a different composition than is used in the other portion. For the example, the preform may be made using a layer of PTFE material mixed with an Isopar-like lubricant, e.g., a simple hydrocarbon solvent of density approximately 0.6, and a layer of the same PTFE material mixed with a heavy oil, such as a more viscous hydraulic pump oil or a glycerin-containing fluid. Following extrusion, both lubricants are baked out, and the final stretched or unstretched article is sintered to fix its microporous structure.
Related effects are also expected when forming a billet wherein one portion has its lubricant less uniformly dispersed in or mixed with the resin. In that case, the voids left upon baking out the lubricant may be expected to result in regions having different nodal size in the coarsely-mixed extrudate than in the well-mixed extrudate. Thus, the invention is understood to include articles formed by extrusion of two different extrusion materials, wherein the materials have the same resin, and differ only in type, quantity, uniformity or other property of the lubricant included in the material.
It will be further understood that while the invention has been described with reference to extrusion of a billet formed of different concentric cylinders to make a tubular item, billets of other shape may advantageously be used to extrude articles of other aspect or shape, such as multi-lumenal solid or perforated bodies as described in applicant's aforesaid co-pending United States patent applications.
Furthermore, a tubular product as described above, may be slit longitudinally to provide a belt-like sheet, and one or more such sheets may be joined or assembled in a multi-layer stack to form an article having through-wall porosities of two or more successive or opposed tapers. In other constructions, a tube as described above may be pressed flat so that it forms a strip two layers thick, with a larger (or smaller) pore structure at its center than at either outside surface.
In addition, as noted above, the invention contemplates the manufacture of articles which have been extruded with a varying lubricant distribution, but not subjected to a stretching or expansion step. These articles have a generally more rigid structure with lower porosity, and do not have the fibril structure characteristic of the expanded product, but may still benefit from the additional control over porosity combined with enhanced microstructure alignment as provided by the present invention, to tailor their mechanical properties.
According to a principal aspect of one presently preferred embodiment of the invention, this structure is employed in a vascular graft, formed of PTFE tube having a lower inside than outside porosity, the variation being introduced by extrusion from a billet having higher outside lube levels, followed by stretching and sintering. Advantageously, the node structure of plate-like sheets oriented perpendicular to the axis of the tube permits deep cellular ingrowth, and provides a flexible anti-kink and non-collapsing lumen structure, yet prevents blood leakage at the smaller-pored wall.
In a proof-of-principle experiment carried out with a tubular prosthesis made in accordance with Method 4 above, the tubes were implanted in the carotid artery of dogs and left in vivo for extended periods to assess patency, cell growth and tissue compatibility. In implants that remained patent, tissue ingrowth had progressed by forty-five days such that morphologically complete normal capillaries had grown through the entire thickness of the tube wall. This single-resin expanded fluoropolymer graft thus appeared to demonstrate, for the first time known to the inventors, an artificial vessel replacement structure essentially capable of supporting natural vessel wall regrowth extending not only along the interior surface, but between the inside and outside surfaces.
It is expected that in other areas where it has historically been possible to achieve tissue growth only for limited times or to limited depths, different forms of prosthesis made in accordance with the above pore-tailoring and uniformity-promoting processes will support enhanced natural or seeded growth of other cell types to form replacement tissue for diverse organs, vessels and tissue structures.
For example, the invention contemplates that an organ prosthesis, partial organ, patch, graft, or organlike structure be formed of material having the desirable permeability to fluids on a macroscopic scale and porosity to receive cellular growth, possibly in connection with one or more lumena defining flow paths therethrough for carrying blood and/or other biological fluids. For a discussion of a range of shaped porous articles intended for diverse such uses, reference is made to applicant's above-mentioned patent applications. Such shapes may be configured to constitute grafts, intended to patch over and regenerate regions of tissue that have been lost to trauma, disease or surgery, or may constitute entire organs. Furthermore, such prostheses need not be patched into an existing organ, but may, for example, be seeded with culturable cells, cultured and implanted into a well-vascularized region capable of supporting tissue growth and of receiving the material expressed by the tissue for circulating it in the bloodstream. Thus, the inventive prosthesis provides a bioreactor for producing biological material, the walls and lumens serving to sustain the culture and allow exchange of cultured products in the body.
For this latter application, the tailored pore structure of articles of the present invention allows tissue growth and exchange of expressed bioactive materials, without allowing exogenous cells to circulate and without allowing immunity-mediating cells to reach the cultured tissue. The cellular containment thus diminishes the likelihood of inducing a whole body rejection or cell-mediated immune response. By way of example, an artificial pancreas for insulin replacement therapy may be formed by seeding a closed multiluminal article to grow islets of Langerhans, with the cell products and secretions entering blood circulating through one or more of the lumena. In this case, it is desirable to culture the cells and supporting material in vitro, and then implant the functioning culture body to initiate insulin or other replacement therapy. In other examples of this method of use of articles of the present invention, endothelial cells may be cultured to provide their cell products into the bloodstream.
Another class of articles of the present invention having varying pore structure is the class of filters or filtration units. For this application, the presence of a tapering pore structure can be used, for example, in different orientations to prevent particles from reaching and clogging subsurface regions of a filter membrane, or to allow greater fluid pressure through the depth of a filter membrane, in each case having the effect of enhancing overall the filter's lifetime, capacity or filtration rate.
Still another class of articles directly pertaining to the present invention is that of culture beds or bioculture reactors, wherein an extrudate, e.g., a porous tube or sheet made in accordance with the invention, serves as the anchoring structure for cellular material--tissue or microorganisms--that synthesize an enzyme or other substance which is the end product of the process. In this case, the porosity, possibly in a tubular or multilumenal structure may allow the transport of nutrients to one side of the article, and the harvesting of product at another or the same side, without having to break up the cell mat to affect such feeding or harvesting.
Further alterations to the above described embodiments of the invention will be apparent to those skilled in the art and are intended, therefore, to be embraced within the spirit and scope of the invention. That is, the preceding detailed description is intended as illustrative rather than limiting. Accordingly, the invention is to be defined not by the preceding detailed description but by the claims that follow. | A method of forming porous articles with a varying pore distribution by extrusion from a billet with a varying lubricant distribution. A single-polymer polytetrafluoroethylene is extruded and then stretched and sintered to provide a differential porous PTFE structure composed of fibers and nodes connected to one another by these fibers. The microfibrous structure has a portion within the cross-section that possesses a different pore size, accompanied by a different node and fiber geometry, than adjacent areas within that cross section. In a vascular graft, the pores taper inwardly, providing a fluid-tight lumen wall structure that prevents leakage, yet promotes cellular ingrowth and natural tissue regeneration. A node structure of radially-oriented plates provides flexibility, suture strength, and enhanced protection against collapse. | 8 |
[0001] This application claims the priority benefit of Taiwan patent application number 096217239 filed on Oct. 15, 2007.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an electric fan and more specifically, to fan blade assembly, which facilitates accurate installation of the core shaft in the fan blade body for enabling the core shaft to support magnetic levitation rotation of the fan blade body stably.
[0004] 2. Description of the Related Art
[0005] Cooling fans are intensively used in different electronic apparatus for quick dissipation of heat energy. When the mechanical operation speed of a cooling fan is increased, the noise level resulted from friction between the core shaft and the axle bearing is relatively increased. Excessive high temperature during operation of a cooling fan may cause burnout of the component parts.
[0006] FIG. 1 illustrates a conventional magnetic levitation motor fan. According to this design, a fan blade assembly, referenced by 1 , of the magnetic levitation motor fan comprises a fan blade body 11 , a core shaft 12 , and magnetic devices 13 . The fan blade body 11 comprises an accommodation chamber 112 , a metal guide plate 113 mounted on the inner surface of the peripheral wall of the accommodation chamber 112 , and a plurality of radial blades 111 equiangularly spaced around the periphery. The magnetic devices 13 are mounted on the magnetic guide plate 113 . The core shaft 12 is vertically downwardly suspending in the accommodation chamber 112 . When the core shaft 12 is coupled to the magnetic levitation motor (not shown), the magnetic devices 13 act with the magnetic levitation motor, causing magnetic levitation rotation of the fan blade assembly 1 . This design of magnetic levitation motor fan still has drawbacks. According to this design, the core shaft 12 is made by means of injection molding and fixedly mounted inside the fan blade body 11 . During installation of the core shaft 12 in the fan blade body 11 , the perpendicularity of the core shaft 12 must be accurately checked. A small deviation of the core shaft 12 will cause unstable rotation of the fan blade assembly 1 . The complicated installation procedure of the core shaft 12 greatly increases the consumption of labor and time during fabrication of the magnetic levitation motor fan.
SUMMARY OF THE INVENTION
[0007] The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a fan blade assembly, which facilitates accurate installation of the core shaft in the fan blade body for enabling the core shaft to support magnetic levitation rotation of the fan blade body stably.
[0008] To achieve this and other objects of the present invention, the fan blade assembly comprises a fan blade body and a core shaft. The fan blade body comprises a center accommodation open chamber and an axle housing downwardly suspending in the center accommodation open chamber at the center. The axle housing has an axle hole axially and downwardly extending to its bottom side, and an inside annular flange transversely extending around the inside wall and suspending in the axle hole. The core shaft is inserted into the axle hole of the axle housing to support rotation of the fan blade body on the core shaft, having a coupling groove extending around the periphery and coupled to the inside annular flange of the axle housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a sectional view of a conventional magnetic levitation motor fan.
[0010] FIG. 2 is a cutaway of a fan blade assembly in accordance with a first embodiment of the present invention.
[0011] FIG. 3 is an exploded view of FIG. 2 .
[0012] FIG. 4 is an enlarged view of a part A of FIG. 2 .
[0013] FIG. 5 is a schematic sectional side view of the fan blade assembly in accordance with the first embodiment of the present invention.
[0014] FIG. 6 corresponds to FIG. 5 , showing a magnetic member fastened to the locating hole of the fan blade body.
[0015] FIG. 7 is a schematic sectional side view of the fan blade assembly in accordance with a second embodiment of the present invention.
[0016] FIG. 8 is a schematic sectional side view of the fan blade assembly in accordance with a third embodiment of the present invention.
[0017] FIG. 9 is a schematic sectional side view of the fan blade assembly in accordance with a fourth embodiment of the present invention.
[0018] FIG. 10 is a schematic sectional side view of the fan blade assembly in accordance with fifth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Referring to FIGS. 2˜4 , a fan blade assembly in accordance with a first embodiment of the present invention is shown comprised of a fan blade body 2 and a core shaft 3 .
[0020] The fan blade body 2 has an accommodation open chamber 22 disposed at the center and facing one side, namely, the bottom side, a plurality of radial blades 21 equiangularly spaced around the peripheral wall of the accommodation open chamber 22 , a metal guide plate 23 mounted on the inner surface of the peripheral wall of the accommodation open chamber 22 , a plurality of permanent magnets 24 affixed to the metal guide plate 23 , a locating hole 26 located at the center of the top wall of the accommodation open chamber 22 and disposed outside the accommodation open chamber 22 for accommodating a magnetic member 27 (see FIG. 6 ), and an axle housing 25 downwardly extending from the center of the top wall of the accommodation chamber 22 opposite to the locating hole 26 and suspending inside the accommodation open chamber 22 . According to this embodiment, the locating hole 26 is a recessed hole. The axle housing 25 has an axle hole 251 axially and downwardly extending to its bottom side, and an inside annular flange 252 transversely extending around the inside wall and suspending in the axle hole 251 . The core shaft 3 is inserted with its one end into the axle hole 251 of the axle housing 25 , having a coupling groove 31 extending around the periphery and forced into coupling with the inside annular flange 252 of the axle housing 25 .
[0021] Referring to FIG. 5 , by means of inserting one end of the core shaft 3 into the axle hole 251 of the axle housing 25 to force the coupling groove 31 into coupling with the inside annular flange 252 of the axle housing 25 , the installation of the core shaft 3 is quite easy, and a user needs not to worry about alignment between the fan blade body 2 and the core shaft 3 . After installation of the core shaft 3 in the axle housing 25 , a gap about 0.1 mm exists between the coupling groove 31 and the inside annular flange 252 , and the permanent magnets 24 are spaced around the core shaft 3 at a distance.
[0022] Referring to FIG. 5 again, when the electric fan is started, the magnetic lines of force of the permanent magnets 24 are separated, and the fan blade body 2 pulled downwards due to the effect of magnetic attraction, keeping the core shaft 3 in position. Because a gap about 0.1 mm exists between the coupling groove 31 and the inside annular flange 252 , the fan blade body 2 is supported on the top edge of the core shaft 3 and made to rotate stably in a magnetic levitation rotation manner. During magnetic levitation rotation of the fan blade body 2 , the axle housing 25 does not touch the core shaft 3 , therefore the friction coefficient between the fan blade body 2 and the core shaft 3 is minimized.
[0023] Referring to FIG. 6 , after installation of the magnetic member 27 in the locating hole 26 of the fan blade body 2 , the magnetic member 27 imparts a magnetically attractive force to the core shaft 3 to secure the core shaft 3 to the inside of the axle hole 251 . At this time, the core shaft 3 has its top edge stopped against the center of the top wall of the accommodation open chamber 22 and is kept suspending in the axle hole 251 without touching the peripheral wall of the axle housing 25 . Therefore, the fan blade body 2 can be rotated stably in a magnetic levitation rotation manner, lowering friction and noise level.
[0024] FIG. 7 is a schematic sectional side view of the fan blade assembly in accordance with a second embodiment of the present invention. This second embodiment is substantially similar to the aforesaid first embodiment with the exception that the locating hole 26 of this second embodiment is a through hole disposed in axial connection with the axle hole 251 , and the top edge of the core shaft 3 is directly stopped against the magnetic member 27 , enhancing the positioning accuracy.
[0025] FIG. 8 is a schematic sectional side view of the fan blade assembly in accordance with a third embodiment of the present invention. This third embodiment is substantially similar to the aforesaid first embodiment with the exception that the locating hole 26 of this third embodiment is a through hole disposed in axial connection with the axle hole 251 , and the top end of the core shaft 3 is inserted into the axle hole 251 and the locating hole 26 and secured in place by a retainer ring 28 that is mounted inside the locating hole 26 .
[0026] FIG. 9 is a schematic sectional side view of the fan blade assembly in accordance with a fourth embodiment of the present invention. This fourth embodiment is substantially similar to the aforesaid first embodiment with the exception that the axle housing 25 according to this fourth embodiment comprises an axially extending axle hole 251 , an annular stop flange 29 suspending at the bottom side of the axially extending axle hole 251 , an axle bearing 32 mounted in the axle hole 251 , and a retaining ring 28 mounted in the axially extending axle hole 251 and stopped between the axle bearing 32 and the annular stop flange 29 and fastened to the coupling groove 31 of the core shaft 3 to secure the top end of the core shaft 3 to the inside of the axle bearing 32 ; the locating hole 26 according to this fourth embodiment is a through hole disposed in axial connection with the axle hole 251 and holding a magnetic member 27 in direct contact with the top edge of the core shaft 3 . According to this fourth embodiment, the axle bearing 32 is a slide bearing.
[0027] FIG. 10 is a schematic sectional side view of the fan blade assembly in accordance with fifth embodiment of the present invention. This fifth embodiment is substantially similar to the aforesaid fourth embodiment with the exception that the axle bearing 32 according to this fifth embodiment is a ball bearing.
[0028] Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. | A fan blade assembly includes a fan blade body, which has an axle housing downwardly suspending in a center accommodation open chamber thereof at the center and defining therein an axle hole and an inside annular flange in the axle hole, and a core shaft, which is inserted into the axle hole of the axle housing to support magnetic levitation rotation of the fan blade body and has a coupling groove extending around the periphery thereof and coupled to the inside annular flange of the axle housing with a gap left therebetween. | 5 |
TECHNICAL BACKGROUND
[0001] The present invention is generally directed to the control of odors resulting from the decomposition of human efflux, and in particular, the effect of a hydroxydiphenyl ether in a modified acidic environment applied to a personal hygiene product to control odors resulting from autolytic and enzymatic decomposition of human exudates and excreta into volatile nitrogenous byproducts.
BACKGROUND OF THE INVENTION
[0002] Disposable absorbent personal hygiene products are designed to capture and retain human excreta in a convenient and in-expensive article. Advances in performance have been made in disposable diapers, adult incontinence pads and feminine hygiene products to further improve waste acquisition and maintain skin wellness. Enhanced top-sheet layers have been introduced that reduce the contact abrasion due to friction of the personal hygiene against one's skin. Transfer intermediate layers are constantly in development whereby the waste, and in particular urine, is quickly wicked from the top-sheet to an absorbent core material. Improved core materials are available that can retain a liquid insult in spite of external compressive forces. While such advances have improved physical performance with regard to liquid and solid wastes, the decomposition of those wastes into volatile byproducts has been addressed with only limited effectiveness.
[0003] Disposable diapers and adult incontinence pads have improved in retention capability and can be worn for longer periods without loss of waste containment. While issues related to containment have improved, the development of odors remains a problem.
[0004] Urine, a primary form of liquid waste encountered by diapers and incontinence pads, is comprised in significant part of urea. The decomposition of urea results in the formation of volatile nitrogenous byproducts, most notably being ammonia, which are particularly malodorous.
[0005] Prior attempts to control ammonia odors have met with limited success. Sequesterants, such as cyclodextrins and zeolite clays are effective only in “capturing” the ammonia once formed. If the structure of the sequesterant becomes occluded or contaminated by the presence of the complex milieu of proteins and salts found in urine, functionality is significantly degraded. The use of acids to shift the pH of the urine insult, and thereby protonate the ammonia into a nonvolatile ammonium ion, has been tried with variable results due, once again, to the chemical complexity inherent to urine. The most practiced method for controlling malodorous decomposition byproducts has been the use of perfumes and fragrances. This practice, however, has generally been found unsatisfactory as ammonia odors are particularly pungent and difficult to mask.
[0006] An alternate method by which ammonia odor may be controlled is to target the degradation pathways, which produce ammonia.
[0007] Autolytic degradation of urea into ammonia occurs when urea is exposed to oxygen. In the environment of a personal hygiene product, and specifically in the fibrous component of a disposable diaper or incontinence pad, urine is wicked into interstices of the product's high loft structure. These interstices form micro-environments where urea autolysis then occurs.
[0008] Enzymatic decomposition is an active process induced by specialized enzymes found in bacterial flora. Many genera of bacteria are ubiquitous to the human skin, the gastrointestinal tract, and the uro-genital tract as well as in the form of environmental contaminates found in the personal hygiene products itself. A general category of enzyme present in this flora allows for the breakdown of urea into ammonia. This enzyme is referred in general as a catalase, and specifically as a urease. When there is a liquid insult onto the hygiene product, bacteria are carried along with the liquid front and into the interstices of the fibrous construction. Ureases in the bacterial burden are active during this period, adding significantly to the production of ammonia. Certain bacteria are particularly receptive to this environment and will thrive, blooming the bacterial count and further increasing urea decomposition over time.
[0009] Various attempts have been made to control bacterial metabolism and bacterial growth, and thereby reduce odors. As in ammonia protonation, the use of acids as a topical treatment is a relatively effective means for skewing the pH of the environment and imparting a deleterious effect on bacterial health. However, problems in attaining and maintaining a desired pH range against the broad range of urine chemistries encountered in the human population in not trivial. Further, producing a uniform distribution of the acid treatment so as to equally affect all microenvironments is complicated by the solubility of the acid.
[0010] There remains an unmet need for an effective treatment for controlling noisome decomposition byproducts, and specifically those byproducts, which are ammonia-based, from developing in soiled personal hygiene products. The odor control mechanism must exhibit sufficient robustness in the face of highly variable human waste chemistries while retaining stability during the hygiene product's shelf-life. The present invention addresses these issues through use of a hydroxydiphenyl ether in a modified acidic environment.
SUMMARY OF THE INVENTION
[0011] The present invention is directed to the control of noisome odors created by the decomposition of human waste in a personal hygiene product. Control of the decomposition process is by the pre-application of an odor control compound comprising a hydroxydiphenyl ether in a modified acidic environment to one or more components of the personal hygiene product. The odor control compound exhibits a multi-functional performance, affecting not only the odiferous decomposition byproducts, but also the biochemical decomposition and degradation pathways.
[0012] Human excreta and exudates are received and absorbed into the personal hygiene product. A particularly problematic human waste control issue involves a urine insult in a diaper or incontinence pad. FIG. 1 and FIG. 2 shows typical hygiene product constructions, whereby the urine contacts 10 or 14 a proximal surface of the hygiene product, then wicks through that surface and one or more other dispersing layers, eventually being absorbed into the structure of a 12 lofty fibrous core. Upon leaving the human body and being sequestered into the 12 absorbent core, the constituent chemistry of the urine begins to decompose. Urea, a compound comprising a significant amount of the urine chemistry, decomposes by autolytic and enzymatic mechanisms. The urea is broken down into nitrogenous volatile byproducts, most notably being ammonia. As ammonia evolves out of the solid hygiene product, both malodorous and detrimental skin-wellness effects occur.
[0013] By employing the compound of the present invention in one or more layers of the personal hygiene product, the production of ammonia is significantly curtailed. The hydroxydiphenyl ether reduces the metabolic performance of bacteria present in the environment. The presence of the hydroxydiphenyl ether in a modified acidic carrier further improves the bacteriostatic performance of the ether as well as introducing a pH shift that disfavors the further release of ammonia by inducing protonation of the ammonia into a nonvolatile ammonium ion.
[0014] The hydroxydiphenyl ether can be present in conjunction with the modified acidic carrier or located within immediate proximity. A preferred embodiment involves the admixing of the hydroxydiphenyl ether with the modified acidic carrier in an aqueous solution. This aqueous solution can then be applied to one or more layers of the personal hygiene product prior to or during product fabrication. Alternately, the hydroxydiphenyl ether can be incorporated into the polymeric composition prior to the formation of that composition into a construct, such as a fiber, filament or film, with the modified acidic carrier being applied topically thereafter. As the hydroxydiphenyl ether blooms to the surface of the construct, interaction with the modified acidic carrier can readily occur.
[0015] Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention will be more easily understood by a detailed explanation of the invention including drawings. Accordingly, drawings, which are particularly suited for explaining the invention, are attached herewith; however, it should be understood that such drawings are for explanation purposes only and are not necessarily to scale. The drawings are briefly described as follows:
[0017] [0017]FIG. 1 is a cross-sectional diagram of a typical personal hygiene product; and
[0018] [0018]FIG. 2 is a cross-sectional diagram of a modified personal hygiene product having a unified top sheet and transfer layer.
DETAILED DESCRIPTION
[0019] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
[0020] To control the production of volatile nitrogenous byproducts, most notably ammonia, produced from the decomposition of urine in a personal hygiene product, a hydroxydiphenyl ether of the following form is used:
[0021] Whereby R′, R″, and R′″, are selected halogen substitutions. A preferred hydroxydiphenyl ether is a trichloro- derivative as described and synthesized in U.S. Pat. Nos. 3,506,720 and 3,629,477, hereby incorporated by reference.
[0022] The trichlorodiphenyl ether exhibits bacteriostatic properties in the presence of the bacterial flora found in the personal hygiene product. It is postulated that the reduction of bacterial load reduces the number of viable and metabolically active bacteria, which results in a corresponding decrease in the concentration of catalases found in those bacteria. A reduction in catalase activity, primarily ureases, subsequently reduces the rate at which urea is decomposed into ammonia, and thereby reducing the noisome odors formed in the hygiene product.
[0023] By introducing the trichlorodiphenyl ether in a modified acidic carrier, performance of the mixture is significantly enhanced. Suitable modified acidic carriers include those acids that shift the pH of the trichlorodiphenyl ether environment to an approximate range of between 3.0 and 5.0. It is within the purview of the present invention that either inorganic or organic acids, alone or in combination, can be used in the capacity of a modified acidic carrier. A presently preferred modified acid carrier is one selected from the aliphatic acids, with hexanedioic acid being most preferred.
[0024] The hydroxydiphenyl ether and modified acid carrier can be incorporated into a personal hygiene product, such as a sanitary napkin, diaper, training pant, incontinence pant, and the like, by a number of different routes, including as a topical treatment, a spin finish, and/or a melt additive. Topical treatment is particularly efficacious in incorporating the odor control compound as a simple aqueous solution can be prepared and applied directly to a substrate material, which is then used as one or more component layers in the fabrication of a personal hygiene product. Suitable substrate materials include nonwoven fabrics, woven fabrics, and films.
EXAMPLES
Example 1
[0025] A 50 gram per square meter nonwoven fabric was fabricated from carded and thermally bonded staple fiber batt. The staple fiber used was a Type T-187 blue pigmented polypropylene polymer with a 1.5″ staple length and a diameter of 12 dpf, as supplied by Fibervisions of Athens, Ga. The staple fiber was carded by conventional practice known to those skilled in the art and subsequently thermal bonded by use of a heated calender. A calender temperature of about 340° F. and a nip pressure of 470 pounds per linear inch were employed.
Example 2
[0026] The nonwoven fabric of Example 1 was subsequently treated with an odor control compound comprising 3 mM trichlorodiphenyl ether, supplied as “MICROBAN” from the Microban Corporation, 68 mM hexanedioic acid, and deionized water. A Weko Atomizer was used to uniformly distribute the odor control compound to the nonwoven fabric at an add-on level of 15% by weight.
[0027] Table 1 presents the effect of untreated and treated nonwoven fabric on bacterial growth. One inch square samples of Example 1 and Example 2 were placed on uniform bacterial lawns, then incubated overnight. Individually tested bacterial organisms where unable to live under the conditions imposed by the treated nonwoven material whereas the untreated material had no effect.
[0028] Table 2 is a variation of the zone of inhibition test performance given in Table 1. A test was performed whereby a bacterial broth receives a one inch sample of either Example 1 or Example 2, then allowed to incubate overnight. When compared to control bacterial broth of known viable organism count, the untreated material is seen to have no significant deleterious effect where as the odor control treated material has reduced viable cell count by at least 95 %.
[0029] Table 3 provides results on the effectiveness of the odor control compound on perceived odor production. Ten inch by seven inch samples were taken from Example 1 and Example 2. These samples were then substituted for the transfer layer of a “SERENITY” brand adult incontinence pant, a registered trademark of Johnson & Johnson, and a five inch square sample of the entire construct excised from the central medial region of the pant. The construct samples were then transferred to the interior bottom surface of individual glass container. A 100 ml volume of mock urine seeded with bacteria was then applied to the samples and the glass containers closed. At time points throughout the testing period, the container was briefly opened and the odor compared against the control. As can be seen from the data provided, the perceived smell was significantly reduced.
[0030] It should be understood that the present invention is applicable to disposable absorbent articles such as incontinence briefs, incontinence undergarments, diapers, training pants, pull-on garments, feminine hygiene garments, sanitary napkins, and the like.
[0031] A diaper, for example, preferably comprises a containment assembly comprising an odor control liquid pervious topsheet; a liquid impervious odor control backsheet joined to the odor control topsheet; and an odor control absorbent core positioned between the odor control topsheet and the odor control backsheet. The odor control absorbent core has a pair of opposing longitudinal edges, an odor control inner surface and outer surface. The diaper can further comprise elastic leg features, elastic waist features, and a landing member.
[0032] From the foregoing, it will be observed that numerous modifications and variations can be affected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims.
TABLE 1 Zone of Inhibition (mm) Staphylococcus Escherichia Proteus Test Material epidermidis coli vulgaris Example 1 0 0 0 Example 2 9 2 9
[0033] [0033] TABLE 2 Viability Count Staphylococcus Escherichia Proteus Test Material epidermidis coli vulgaris Example 1 100% 100% 100% Example 2 0.36% 0.66% 4.58%
[0034] [0034] TABLE 3 Perceived Odor (reduction in odor) Test Material 1 hr 2 hr 4 hr 6 hr 8 hr 12 hr Example 1 0% 0% 0% 0% 0% 0% Example 2 17% 41% 18% 30% 26% 42% | The present invention is directed to the control of noisome odors created by the decomposition of human waste in a personal hygiene product. Control of the decomposition process is by the pre-application of an odor control compound comprising a hydroxydiphenyl ether in a modified acidic environment to one or more components of the personal hygiene product. The odor control compound exhibits a multi-functional performance, affecting not only the odiferous decomposition byproducts, but also the biochemical decomposition and degradation pathways. | 0 |
REFERENCE To RELATED APPLICATIONS
[0001] The Present Disclosure claims priority to prior-filed Korean Patent Application No. 10-2013-0065152, entitled “Mounting Structure And Method Of Connector For Flexible Cable,” filed on 7 Jun. 2013 with the Korean Patent Office. The content of the aforementioned Patent Application is incorporated in its entirety herein.
BACKGROUND OF THE PRESENT DISCLOSURE
[0002] This Present Disclosure relates, generally, to a flexible cable connector, and, more specifically, to a mounting structure and method for a flexible cable connector wherein the cable is mounted on the upper surface of a printed circuit board (PCB), but the soldering takes place on the lower surface of the PCB.
[0003] In order to increase the degree of design freedom in information technology products and the like, the use of flexible printed circuits or flexible flat cables, rather than rigid PCBs, has become widespread. Typically, a connector is used in order to electrically connect a flat circuit cable of this type with a PCB.
[0004] Recently, as the thickness of electronic products with parts mounted therewithin including flexible cable connectors has decreased, two-sided PCBs have gradually been replaced by one-sided PCBs. On one-sided PCBs, a pattern is formed only on the top, and there are no holes connecting top and bottom. The bottom serves only as a base, which has the advantage of reducing production costs. An example of a flexible cable connector being mounted to a one-sided PCB is disclosed in Korean Patent No. 1221506, applied for and registered by the Present Applicant. The content of this Patent is incorporated by reference in its entirety herein. In addition to this, due to the above-mentioned advantages, many flexible cables are mounted to one-sided PCBs.
[0005] However, although flexible cable connectors like that disclosed in the '506 Patent do have the above-mentioned advantages, it is often difficult to secure space between parts for soldering, because all parts must be soldered at the same time they are mounted.
SUMMARY OF THE PRESENT DISCLOSURE
[0006] The purpose of the Present Disclosure, devised in order to resolve the above-described disadvantages, is to provide an installation structure and method for a flexible cable connector that can enable sufficient soldering space for parts that are mounted to the PCB, by having the parts be mounted to the upper surface of the PCB, but have the soldering take place on the lower surface. Another object of the Present Disclosure is to provide an installation structure and method for a flexible cable connector that enables the flexible cable connector to be firmly mounted to the PCB because the soldering to the PCB takes place in four directions of the housing.
[0007] The flexible cable mounting structure of the Present Disclosure is a flexible cable connector comprising a housing, whereon a contact terminal is mounted that enables insertion and withdrawal of the flexible cable and contact with the flexible cable. An actuator that opens/closes is installed to enable rotation on the housing. A fitting nail is furnished on the housing that fixes the housing to the PCB. The fully-assembled flexible cable connector, wherein the contact terminal, actuator, and fitting nail have each been mounted to the housing, passes through from the bottom to the top of the PCB, and the bottom of the contact terminal and bottom of the fitting nail are soldered to the lower surface of the PCB.
[0008] The contact terminal protrudes toward the back of the housing and is soldered to the lower surface of the PCB. The fitting nail protrudes toward either side and the front of the housing and is soldered to the lower surface of the PCB. The flexible cable is inserted and withdrawn via the front face of the housing, and is rotated backward when the actuator is closed.
[0009] When the actuator closes, the terminus protrudes further toward the back than the back end of the housing. The protruding terminus contacts the upper surface of the PCB when the actuator is depressed, and the support projection that supports the actuator is made to protrude downward. The actuator has a closing prevention structure so that when the fully-assembled flexible cable connector penetrates the PCB, the actuator remains in its open state. Further, the actuator is fixed rotatably on the side fitting nail furnished on either side of the housing. In the part of the actuator rotation axle, which contacts the side fitting nail, that touches the top of the side fitting nail, a flat area is formed so that the actuator is kept open. When the flexible cable inserted, the flexible cable remains a distance from the PCB.
[0010] The method of the Present Disclosure for mounting a flexible cable connector comprises: (a) a step wherein a flexible cable is assembled by mounting a contact terminal, actuator, and fitting nail on a housing; (b) a step wherein the fully-mounted flexible cable connector is inserted into the connector through hole of the flipped PCB with the actuator in open state; (c) a step wherein the bottom end of the contact terminal protruding outside the housing and the bottom end of the fitting nail are soldered to the soldering surface so as to contact the lower surface of the PCB; (d) a step wherein after soldering, the PCB is flipped and a flexible cable is inserted into the housing; and (e) a step wherein the actuator is closed by rotating backwards. In step (b), the actuator remains in open state. In step (d), the actuator is further rotated forward so as to facilitate insertion of the flexible cable.
[0011] The flexible cable connector mounting structure and method of the Present Disclosure has the following effects. First, because the flexible cable connector is mounted to the upper surface of the PCB but soldering takes place on the lower surface of the PCB, it facilitates circuit configuration because sufficient soldering space for other parts that are mounted to the top of the PCB can be secured. Second, the flexible cable connector can be firmly mounted to the PCB because the soldering to the PCB takes place in the four directions of the housing. Specifically, if a conventional flexible cable connector was soldered to the upper surface of the housing, there were no problems in reliability of mounting even through it was only soldered to the PCB in three directions of the housing. But, if the soldering took place on the lower surface of the PCB, then if the soldering took place only in three directions of the housing, then when the actuator was depressed in order to close it, the reliability of the connector mounting was unavoidably impaired; this can be resolved by soldering in four directions of the housing.
BRIEF DESCRIPTION OF THE FIGURES
[0012] The organization and manner of the structure and operation of the Present Disclosure, together with further objects and advantages thereof, may best be understood by reference to the following Detailed Description, taken in connection with the accompanying Figures, wherein like reference numerals identify like elements, and in which:
[0013] FIG. 1 is a cross-section of a flexible cable connector mounting structure according to a preferred embodiment of the Present Disclosure;
[0014] FIG. 2 is an oblique view showing the flexible cable connector of FIG. 1 , separated from a printed circuit board;
[0015] FIG. 3 is an exploded oblique view of the flexible cable connector of FIG. 1 ;
[0016] FIG. 4 is a bottom view of the flexible cable connector of FIG. 1 ;
[0017] FIGS. 5-8 show the process of mounting the flexible cable connector of FIG. 1 ;
[0018] FIG. 9 is a partial cutaway view of the housing in order to show the state in which the actuator is rotatably coupled to the side fitting nail; and
[0019] FIG. 10 shows the state in which the respective sides of the actuator are rotatably coupled to the side fitting nail.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] While the Present Disclosure may be susceptible to embodiment in different forms, there is shown in the Figures, and will be described herein in detail, specific embodiments, with the understanding that the Present Disclosure is to be considered an exemplification of the principles of the Present Disclosure, and is not intended to limit the Present Disclosure to that as illustrated.
[0021] As such, references to a feature or aspect are intended to describe a feature or aspect of an example of the Present Disclosure, not to imply that every embodiment thereof must have the described feature or aspect. Furthermore, it should be noted that the description illustrates a number of features. While certain features have been combined together to illustrate potential system designs, those features may also be used in other combinations not expressly disclosed.
[0022] Thus, the depicted combinations are not intended to be limiting, unless otherwise noted.
[0023] In the embodiments illustrated in the Figures, representations of directions such as up, down, left, right, front and rear, used for explaining the structure and movement of the various elements of the Present Disclosure, are not absolute, but relative. These representations are appropriate when the elements are in the position shown in the Figures. If the description of the position of the elements changes, however, these representations are to be changed accordingly.
[0024] With reference to the Figures, according to the flexible cable connector mounting structure of the Present Disclosure, the connector 1 penetrates the PCB 2 with the housing 10 , contact terminal 20 , actuator 30 and fitting nails 40 , 50 assembled. The connector 1 then is mounted on the PCB 2 passing through the PCB 2 from below to above. The actuator 30 and the part of the housing 10 whereinto the flexible cable 3 is inserted are located on the top of the PCB 2 . The terminus of the contact terminal 20 protrudes beyond the housing 10 , and the bottoms of the fitting nails 40 , 50 are soldered to the lower surface of the PCB 2 . A connector through hole 2 a is formed on the PCB 2 wherethrough the connector 1 penetrates. Solder surfaces 2 b, 2 c, where soldering takes place are formed near the connector through hole 2 a on the lower surface of the PCB 2 . When the flexible cable 3 is inserted into the housing 10 , the flexible cable 3 can be readily inserted and withdrawn because the flexible cable 3 is set apart from the PCB 2 .
[0025] As shown in FIG. 1 , when the actuator 30 closes, the terminus protrudes backward beyond the back of the housing 10 . On the protruding terminus, a support projection 31 protrudes backward that supports the actuator 30 while contacting the upper surface of the PCB 2 when the actuator 30 is depressed. The location where the support projection 31 makes contact should preferably be on the opposite side from the soldering surface 2 b where the contact terminal 20 is soldered. By means of this structure, when the actuator 30 is pressed closed by hand, deformation of these parts is prevented without causing any problem for the part that is soldered to the PCB 2 .
[0026] As described above, the flexible cable connector 1 comprises a housing 10 , contact terminal 20 , actuator 30 and fitting nails 40 , 50 . The flexible cable can be inserted and withdrawn via the front part of the housing 10 . The contact terminals 20 that contact the flexible cable are mounted to the housing 10 via the back part. The contact terminals 20 are mounted on the housing 10 to contact the flexible cable that is inserted into the housing 10 . The bottom of the contact terminal 20 is soldered to the soldering surface (pattern) formed on the lower surface of the PCB.
[0027] The actuator 30 is installed rotatably on the housing 10 , so that when it is open the flexible cable can be inserted and after the flexible cable has been inserted, it is closed by rotating backward, thus enabling the flexible cable to reliably make contact with the contact terminal 20 . Because the actuator 30 tightly presses the flexible cable and the contact terminal 20 together when the actuator 30 is in closed position, the contact between the flexible cable and the contact terminal 20 remains stable unless the flexible cable is manually pulled out.
[0028] The fitting nails 40 , 50 are furnished on the housing 10 to hold the housing 10 firmly to the PCB 2 , and comprise a pair of side fitting nails 40 fixed to either side of the housing 10 , and a plurality of front fitting nails 50 fixed to the front part of the housing 10 . On either side of the housing 10 , the side fitting nails 40 are affixed in a sliding fashion. On the front of the housing 10 , a plurality of fitting nail holding grooves 11 are formed at a distance from one another, whereinto the front fitting nails 50 are inserted.
[0029] As shown in FIG. 4 , when the contact terminal 20 , side fitting nails 40 and front fitting nails 50 are assembled on the housing 10 , the bottom parts thereof protrude beyond the housing 10 . Specifically, the bottom of the contact terminal 20 protrudes behind the housing 10 , the side fitting nails 40 protrude to either side of the housing 10 , and the front fitting nails 50 protrude in front of the housing 10 .
[0030] Before the flexible cable connector 1 is mounted, an assembly process is conducted wherein the contact terminal 20 , actuator 30 and fitting nails 40 m 50 are assembled on the housing 10 . After the flexible cable connector 1 has been assembled, as shown in FIG. 5 , the connector 1 is inserted into the connector through hole 2 a of the PCB 2 from above to below (from the lower surface to the upper surface of the PCB), with the PCB 2 flipped and the flexible cable connector 1 that was assembled using the pickup nozzle 4 also in a flipped state. The actuator 30 must be opened vertically, as shown in the Figures, in order for the actuator 30 not to catch on the entrance to the connector through hole 2 a in the insertion process.
[0031] Because the terminus of the actuator 30 protrudes backward from the housing 10 , if the connector 1 is inserted when the actuator 30 is in closed position, the terminus of the actuator 30 catches on the connector through hole 2 a, and consequently the connector 1 is inserted when the actuator 30 has been opened.
[0032] As shown in FIG. 6 , if the assembled flexible cable connector 1 has been entirely inserted, the bottoms of the contact terminals 20 that protrude outward from the housing 10 and the bottoms of the fitting nails 40 , 50 respectively are contacted and soldered to the soldering part formed on the lower surface of the PCB 2 . After soldering has been conducted, as shown in FIG. 7 , the PCB 2 is flipped over and the actuator 30 in vertical state is further rotated forward to open it further, so that the flexible cable can be readily inserted.
[0033] After the actuator 30 has been fully opened, as shown in FIG. 8 , the flexible cable 3 is inserted, and the actuator 30 is closed by rotating backward. As the actuator 30 is closed, the flexible cable 3 and contact terminals 20 are firmly pressed together for a stable connection. In the process of closing the actuator 30 , the terminus of the actuator 30 is depressed by hand; the support projection 31 formed on the terminus of the actuator 30 is contacted with the upper surface of the PCB 2 to support the actuator 30 .
[0034] At the top end of the side fitting nails 40 , a rotation axle insertion part 41 is formed in the form of a hole whereinto the rotation axle 32 formed on either side of the actuator 30 is inserted. The rotation axle insertion part 41 has a shape that is opened toward the back.
[0035] When the actuator 30 is opened vertically, the part of the exterior surface of the rotation axle 32 that touches the top of the rotation axle insertion part 41 is formed as a flat space 32 a. Accordingly, when the actuator 30 is opened vertically, the actuator 30 is kept in its vertically opened state, preventing closure, unless the actuator 30 is pushed manually.
[0036] According to the above-described flexible cable connector mounting structure and method of the Present Disclosure, the following technical characteristics can be expected. First, because the flexible cable connector 1 is mounted to the upper surface of the PCB 2 , but soldering takes place on the lower surface of the PCB 2 , it facilitates circuit configuration because sufficient soldering space for other parts that are mounted to the upper surface of the PCB 2 can be secured. Especially pronounced effects can be obtained if parts are mounted to only one side of the PCB 2 for purposes of enhancing the thinness of the electronic product.
[0037] Second, the flexible cable connector 1 can be firmly mounted to the PCB 2 because the soldering to the PCB 2 takes place in four directions of the housing 10 . Specifically, if a conventional flexible cable connector was soldered to the top surface of the housing, there were no problems in reliability of mounting even through it was only soldered to the PCB 2 in three directions of the housing. However, if the soldering took place on the lower surface of the PCB, then if the soldering took place only in three directions of the housing, then when the actuator was depressed in order to close it, the reliability of the connector mounting was unavoidably impaired. This can be resolved by the Present Disclosure by adding front fitting nails 50 and soldering in four directions of the housing 10 .
[0038] While a preferred embodiment of the Present Disclosure is shown and described, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the foregoing Description and the appended Claims. | The flexible cable mounting structure of the Present Disclosure is a flexible cable connector comprising a housing, whereon a contact terminal is mounted that enables insertion and withdrawal of the flexible cable and contact with the flexible cable. An actuator that opens/closes is installed in such a way as to enable rotation on the housing. A fitting nail is furnished on the housing and fixes the housing to the PCB. The fully-assembled flexible cable connector, wherein the contact terminal, actuator, and fitting nail have each been mounted to the housing, passes through from the bottom to the top of the PCB, and the bottom of the contact terminal and bottom of the fitting nail are soldered to the lower surface of the PCB. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/952,956 filed Nov. 23, 2010 and claims priority of German patent application No. 10 2009 047 196.0 filed Nov. 26, 2009.
BACKGROUND OF THE INVENTION
The invention relates to a process for preparing 1,6-hexanediol, in which a hexanediol having a proportion by weight of nitrogen of less than 5 ppm is obtained, 1,6-hexane-diol having a proportion by weight of nitrogen of less than 5 ppm and also the use of this 1,6-hexanediol for preparing polymers.
There is a great demand for 1,6-hexanediol which has no amines in amounts which have a catalytic effect in the preparation of polyurethanes, since these catalytic amounts of amines lead to considerable amounts of by-products which hinder the reaction to form the polyurethane.
DE 10112117 A1 describes a process for removing nitrogen-comprising compounds using acidic and/or basic ion exchangers. The proportion by weight of nitrogen is determined here by means of a CPR (controlled polymerization rate). This purification process has the disadvantage that the use of acidic and/or basic ion exchangers leads to increased costs since the ion exchangers themselves represent costs and their use means an increased use of solvents since ion exchangers are only finitely useable and have to be regenerated every now and again. In addition, to avoid losses of product, rinsing of the ion exchanger is necessary and leads to increased use of solvents or regeneration media. Since 1,6-hexanediol is solid under normal conditions, the feed to the ion exchanger has to be additionally heated for a reaction over the ion exchanger to be possible at all. Thus, the process for purifying polyalcohols in DE 101112117 A1 has considerable disadvantages. Furthermore, DE 101112117 A1 does not describe the removal of nitrogen-comprising compounds from 1,6-hexanediol.
The preparation of 1,6-hexanediol starts out from the appropriate cyclo-C 6 -alkanes, alcohols, ketones and/or mixtures of these compounds, and these are either oxidized in the presence of nitric acid and/or subjected to oxidation with subsequent water extraction of the organic stream.
In the case of 1,6-hexanediol, streams comprising adipic acid are produced in this way from, for example, cyclohexanol and/or cyclohexanone by oxidation using nitric acid. For the present purposes, streams comprising adipic acid are streams which can comprise adipic acid itself or else adipic acid in the form of its esters. In the oxidation, it is possible to use both the adipic acid obtained by oxidation and the mixture remaining after the adipic acid has largely been separated off, which mixture comprises adipic acid, glutaric acid and succinic acid.
Furthermore, other sources of adipic acid or streams comprising adipic acid are in principle streams which can be mixed with the abovementioned streams, for example streams obtained by oxidation of cyclohexane to cyclohexanol/cyclohexanone mixtures and subsequent water extraction of the organic stream.
The abovementioned streams usually comprise impurities which in the case of the oxidation of cyclohexanol/cyclohexanone are formed by oxidation using nitric acid and comprise nitrogen. Nitrogen components are also present as undesirable secondary components in the water extracts after the oxidation of cyclohexane by means of air.
These nitrogen compounds, which can be present, for example, as nitro group, amides or ammonium ion, are able to form amines during the hydrogenation of streams comprising adipic acid, which can also be esterified. For example, nitro compounds can be hydrogenated directly to amines and/or amides. Ammonium ions can aminate alcohols formed during the hydrogenation.
Amines are basic components and as such are undesirable in 1,6-hexanediol since they have properties which are undesirable in the uses of 1,6-hexanediol. Thus, these amines can, for example, have a catalytic action in the preparation of polyurethanes, so that process control for preparing a product having precisely defined properties is difficult if not impossible. It can happen that entire production batches have to be disposed of. This also applies in principle in the preparation of polyesters or polyester alcohols which are then again reacted further with isocyanates to form urethanes.
One possible way of establishing whether undesirable N-comprising compounds are present in the form of basically acting amines in 1,6-hexanediol is to determine the CPR (controlled polymerization rate). The content of basically acting amine is accordingly coupled with the CPR and can, as explained for the example of 1,6-hexanediol, be determined as follows:
30 g of 1,6-hexanediol are dissolved in 100 ml of a solution of potassium hydroxide in methanol (0.001 mol/l) and stirred for 15 minutes. This solution is, for example, titrated potentiometrically with 0.01N hydrochloric acid to the end point using a Titroprocessor 682™ from Metrohm, Herison, Switzerland. The Titroprocessor 682 is equipped with two pH electrodes, viz. a glass electrode (3 M KCl, Metrohm 6.0133.100) and an Ag/AgCl/LiCl electrode (alcohol, Metrohm 6.0726.100). The procedure is repeated using a comparative solution comprising 100 ml of a solution of potassium hydroxide in methanol (0.001 mol/l) to determine the blank.
The CPR is determined from the two results of potentiometric titration as follows:
CPR= 10×( V 1 −V 2), where
V1 is the consumption of 0.01N hydrochloric acid in the case of the polyalcohol sample, V2 is the consumption in the comparison (blank) and 10 corresponds to the calculation factor in accordance with JIS (Japan Industrial Standard) K 1557-1970.
For example, at a CPR of 10, i.e. a net hydrochloric acid consumption of 1 g of 0.01 molar HCl, about 5 ppm of N is present in the 1,6-hexanediol. Such a CPR of 10, i.e. an N content of 5 ppm, is already an undesirably high level and can cause considerable secondary reactions in subsequent polyurethane reactions.
It is therefore an object of the present invention to provide a process which makes it possible to prepare 1,6-hexanediol having a CPR of less than 10, without an additional outlay and costs associated with additional solvents and/or acidic and/or basic ion exchangers having to be incurred.
BRIEF SUMMARY OF THE INVENTION
This object is achieved by a process for purifying 1,6-hexanediol, which comprises the following steps
I) provision of a mixture comprising 1,6-hexanediol II) distillation of this mixture from step I III) collection of a 1,6-hexanediol having a nitrogen content of less than 5 ppm,
wherein more than 500 ppm of carboxylic acids and/or esters which have a boiling point higher than that of 1,6-hexanediol and are in contact with the 1,6-hexanediol at temperatures of ≧100° C. for at least 5 minutes are comprised before and/or during the distillation in step II.
DETAILED DESCRIPTION OF THE INVENTION
In the process of the invention, it is necessary for the mixture from step I of the process of the invention which is to be distilled to comprise not only 1,6-hexanediol but also carboxylic acids and/or esters which have a boiling point higher than that of 1,6-hexanediol itself. This can be achieved by the mixture used in step I) comprising not only 1,6-hexanediol but also carboxylic acids and/or esters which form higher-boiling esters with 1,6-hexanediol or else, before and/or during the distillation in step II, either carboxylic acids and/or esters having a boiling point higher than that of 1,6-hexanediol (high boilers) being added to the mixture from step I or carboxylic acids and/or esters which react with part of the 1,6-hexanediol to form esters which after the reaction have a boiling point higher than that of 1,6-hexanediol are added. It is also possible to use mixtures of high boilers and carboxylic acids and/or esters which with 1,6-hexanediol form esters having a boiling point higher than that of 1,6-hexanediol itself.
When high boilers or carboxylic acids and/or esters which form higher-boiling esters with 1,6-hexanediol itself are added before and/or during the actual distillation in step II, then the distillation has to be carried out so that these high boilers and/or higher-boiling esters are in contact with the 1,6-hexanediol in the mixture from step I for a particular time before the 1,6-hexanediol is distilled off. This contact time during the distillation has to be at a temperature of ≧100° C. for at least 5 minutes. Preference is given to a contact time of ≧10 minutes, particularly preferably a contact time of ≧15 minutes. For the purposes of the present invention, the contact time is the time for which the 1,6-hexanediol is in contact with the high boiler and/or the higher-boiling esters in the liquid or gaseous state within the column. The contact space in which the 1,6-hexanediol has to be in contact with the high boiler and/or the higher-boiling esters is the entire column and also the associated piping and, if appropriate, the vaporizer. The contact space thus comprises the packing within the column, the collectors and distributors and also the associated piping, the bottom of the column and also any attached vaporizer and the pipe to this.
The temperature during the contact time should be ≧100° C., preferably at least 120° C., particularly preferably at least 140° C.
The carboxylic acids and/or esters which are if appropriate added to the mixture from step I before the distillation in step II are selected from the group consisting of adipic acid, adipic esters, 6-hydroxycaproic acid, 6-hydroxycaproic esters. Particular preference is given to the esters selected from the group consisting of dimethyl adipate, methyl 6-hydroxycaproate, 1,6-hexanediol methyl adipate, the di-1,6-hexanediol ester of adipic acid, the 1,6-hexanediol ester of 6-hydroxycaproic acid and mixtures of these esters.
The amount of carboxylic acids and/or esters which are reacted with the 1,6-hexanediol to form the higher-boiling esters and also the amount of high boilers added and the amount of mixtures of added high boilers and carboxylic acids and/or esters which are reacted with 1,6-hexanediol to form the higher-boiling esters are in the range of ≧500 ppm, preferably in the range of ≧1000 ppm, particularly preferably ≧1500 ppm, based on the amount of 1,6-hexanediol to be distilled.
The pressures during the distillation are preferably in the range from 5 to 3000 mbar absolute. Before the actual distillation in step II of the process of the invention, other compounds can, if appropriate, be distilled off beforehand. These are in particular compounds which have a boiling point at least 50° C. lower than that of 1,6-hexanediol itself and are referred to as low boilers. The low boilers are preferably selected from the group consisting of methanol, water, dimethyl ether, 1-hexanol and 1-methoxy-6-hydroxyhexane. The low boilers can be separated off in a separate column which is located upstream of the distillation in step II. The pressure within this column for separating off the low boilers is, for example when methanol and/or water are to be separated off, in the range from 200 to 3000 mbar absolute, and when 1,6-hexanediol is to be separated off from high boilers and/or the higher-boiling esters, the pressure during this distillation is in the range from 5, preferably 10 to 500 mbar absolute, preferably in the range from 20 to 300 mbar absolute, particularly preferably in the range from 30 to 200 mbar absolute.
The distillations can be carried out as batch process or continuously, but preference is given to continuous operation, especially when 1,6-hexanediol is to be produced in industrial amounts.
To prepare 1,6-hexanediol having a proportion by weight of nitrogen of less than 5 ppm, adipic acid which has been prepared either by oxidation of cyclohexanol and/or cyclohexanone by means of nitric acid, by oxidation of cyclohexane to cyclo-hexanol/cyclohexanone mixtures and subsequent water extraction of the organic stream or by oxidation of cyclohexane by means of air and subsequent water extraction is used as starting material. Here, the adipic acid comprising the solutions is esterified with an alcohol selected from the group consisting of methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, pentanols, hexanols, 2-ethylhexanol, 2-propylheptanol, 1,5-pentanediol, 1,6-hexanediol, tridecanol, pentadecanol and mixtures of the alcohols, preferably methanol, ethanol, propanol, n-butanol and 1,6-hexanediol. Particular preference is given to methanol and 1,6-hexanediol for esterification. The subsequent hydrogenation can be carried out in the gas phase or in the liquid phase.
When the subsequent hydrogenation is to be carried out in the gas phase, methanol is preferred as alcohol for esterification.
If hydrogenation is to be carried out in the liquid phase, not only methanol but also 1,6-hexanediol are preferred.
The alcohol is used in an at least equimolar amount relative to the carboxyl groups of the adipic acid and, if appropriate, other carboxyl groups of other acids which may be present. However, preference is given to a molar excess of alcohol per carboxyl group of at least 2.
The esterification can proceed without added catalyst, but preference is given to using one catalyst after an acid conversion of 50% by weight. This can be, for example, sulfuric acid or sulfonic acids, but also acidic solids such as ion exchangers, usually ion exchangers based on sulfonic acid.
The water of reaction formed is preferably separated off during the esterification, e.g. by distillation. Alcohol is also entrained. For this reason, preference is given to distilling the alcohol/water mixture separately and recirculating the alcohol.
Depending on the esterification technology, the dialkyl adipate can be obtained in a form ready for use in the hydrogenation, but it can also be that alcohol and water still have to be separated off or the dialkyl adipate has to be purified by distillation in order to separate off incompletely reacted acid which is either disposed of or preferably, if appropriate after discharge of a small percentage to avoid accumulation of undesirable components, recirculated to the esterification. The optionally purified dialkyl adipate is subsequently hydrogenated.
This can occur in the liquid phase or gas phase, preferably over Cu-comprising catalysts.
In the liquid-phase hydrogenation, preference is given to employing pressures of 100-330 bar absolute, preferably a gauge pressure of 150-270 bar, while in the gas phase a gauge pressure of from 5 to 100 bar is appropriate, with particular preference being given to from 20 to 70 bar.
It is advantageous for the hydrogenation product mixture still to comprise carboxyl groups, preferably esters. These can be, for example, dimethyl adipate, methyl 6-hydroxycaproate, 1,6-hexanediol methyl adipate, the di-1,6-hexanediol ester of adipic acid and/or the 1,6-hexanediol ester of 6-hydroxycaproic acid. If exclusively or virtually exclusively dimethyl adipate and/or methyl 6-hydroxycaproate are to be present as carboxyl-comprising compounds in the hydrogenation product mixture, it has to be ensured in the subsequent distillation stage(s) or in a separate stage that these esters are not distilled off completely from 1,6-hexanediol. In the process of the invention, these esters are reacted with 1,6-hexanediol at temperatures of ≧100° C. to form corresponding esters having a boiling point higher than 1,6-hexanediol itself. These corresponding higher-boiling esters are selected from the group consisting of 1,6-hexanediol methyl adipate, the di-1,6-hexanediol ester of adipic acid and/or the 1,6-hexanediol ester of 6-hydroxycaproic acid. The content of these higher-boiling esters based on the content of 1,6-hexanediol is at least 500 ppm, preferably ≧1000 ppm, particularly preferably ≧1500 ppm.
The reaction of dimethyl adipate and methyl 6-hydroxycaproate with 1,6-hexanediol can occur either purely thermally or in the presence of catalytically active compounds such as acids or bases. Preference is given to the thermal variant in which the temperature is ≧100° C. and the time for which the esters and 1,6-hexanediol are in contact has to be at least 5 minutes. Preference is given to temperatures of ≧120° C. and contact times of ≧10 minutes.
In a preferred embodiment, if methyl esters have been used in the hydrogenation, at least 50% of the methanol has been removed by distillation before this contact time. This is preferably combined with the methanol removal step which precedes the actual distillation in step II.
The mixture comprising 1,6-hexanediol, the high boilers, higher-boiling esters and if appropriate low boilers is fractionally distilled. Here, compounds having a boiling point lower than that of 1,6-hexanediol, for example the low boilers such as methanol, are preferably separated off by distillation in a first distillation unit, e.g. a continuously operated column. By-products such as water and dimethyl ether are obtained together with the methanol. In the distillation, the energy is preferably introduced via the bottom of the column, for example by means of a bottom circuit. The temperature at the bottom should be at least 100° C. It is advantageous to keep the temperature of the feed to the column above 20° C., for example at the level at which the hydrogenation product mixtures are obtained so that their thermal energy can be utilized in the column. The average residence time of the 1,6-hexanediol together with the abovementioned high boilers and higher-boiling esters at temperatures of at least 100° C. in this column is at least 5 minutes. This 1,6-hexanediol-comprising stream is advantageously processed in a further column to give 1,6-hexanediol having a proportion by weight of nitrogen of less than 5 ppm. Here, it is possible to use, for example, a dividing wall column or a column having a side offtake in which the low boilers such as 1-hexanol, 1-methoxy-6-hydroxyhexane together with very little 1,6-hexanediol are distilled off at the top, high boilers and/or higher-boiling esters which likewise comprise very little 1,6-hexanediol are taken off at the bottom and liquid or gaseous 1,6-hexanediol having a nitrogen content of less than 5 ppm is taken off via the side offtake. This 1,6-hexanediol preferably comprises less than 3 ppm of nitrogen. This column is operated at a temperature at the bottom of above 100° C. and average residence times of more than 5 minutes. The nitrogen-comprising components are discharged to an extent of at least 50% with the high-boiling bottom stream.
Instead of the one column having a side offtake, it is also possible to use two separate columns, with low boilers being removed at the top in the first column and the 1,6-hexanediol then being distilled off from high boilers and/or higher-boiling esters in the second column. A temperature of at least 100° C. with average residence times of at least 5 minutes is set at the bottom of at least the first of the two columns.
To prepare relatively small amounts of 1,6-hexanediol, use can also be made of batch columns in which the hexanediol is purified batchwise. Here, low boilers compared to hexanediol are separated off first, followed by the 1,6-hexanediol itself. High boilers and higher-boiling esters comprising the nitrogen components remain in the bottom.
A further variant is to add carboxyl-comprising components other than carboxylic acids and esters after the hydrogenation. These compounds are, for example, aldehydes and ketones which with the 1,6-hexanediol form compounds which have boiling points higher than that of 1,6-hexanediol itself.
If water is used as solvent, it is useful to hydrogenate the adipic acid itself. As hydrogenation catalyst, it is then possible to use, for example, Co- , Re- and Ru-comprising catalysts. Here too, the conversion of carboxylic acids and/or esters should be incomplete, so that the proportion of carboxylic acids and/or esters in the hydrogenation product mixture is preferably above 500 ppm, particularly preferably above 1000 ppm.
The 1,6-hexanediol prepared in this way, which has a nitrogen (N) content of less than 5 ppm, can be used in any process for preparing polymers in which diols are used. Since the 1,6-hexanediol has an N content of less than 5 ppm, polymers can be obtained therefrom without problems. The 1,6-hexanediol obtained according to the invention is preferably used for the preparation of polyurethanes and polyesters. Here, the 1,6-hexanediol is reacted with diisocyanates such as hexamethylene diisocyanate, tolylene 2,4-diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate and 4,4′-diisocyanatodicyclohexylmethane to form polyurethanes. To prepare polyesters, the 1,6-hexanediol obtained according to the invention is used in the presence of dicarboxylic acids such as succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, dodecanedioic acid, terephthalic acid, isophthalic acid and phthalic acid.
EXAMPLES
Example 1
Adipic acid, obtainable as product of the oxidation of cyclohexanol/cyclohexanone by means of nitric acid, having a content of 4 ppm of nitrogen is esterified by means of an acidic ion exchanger as catalyst (Amberlite IR 120) and methanol to form dimethyl adipate. After complete esterification and removal of the ion exchanger and excess methanol, the ester is distilled (18 mbar, boiling point: 115° C.) and obtained in a purity of 99.98%. The nitrogen (N) content of the ester was 4 ppm. The dimethyl adipate is hydrogenated in the gas phase at 60 bar and 195-210° C. over a copper-comprising catalyst. The space velocity over the catalyst is 0.15 kg of ester feed/liter of catalyst per hour. The reactor is a shaft reactor preceded by a vaporizer in which the feed stream is vaporized at about 195° C. with the aid of a stream of hydrogen gas. The stream of hydrogen gas is composed of fresh gas (4.5 mol/mol of dimethyl adipate) and a recycle gas stream (about 80 mol of hydrogen/mol of feed stream). Downstream of the reactor, the gaseous mixture is cooled and liquid products are taken off. The gaseous output is recirculated by means of a recycle gas compressor. A small part of the gas stream is discharged as offgas. The dimethyl adipate conversion is about 99.9%. A little methanol was lost via the offgas stream. The collected outputs (about 30% by weight of methanol, about 68% by weight of 1,6-hexanediol, about 0.5% by weight of methyl 6-hydroxycaproate and 0.06% by weight of hexanediol ester of 6-hydroxycaproic acid, about 0.3% by weight of hexanol, 0.1% by weight of dimethyl adipate, balance in each case below 0.1% by weight) have an N content of 5 ppm and are worked up by distillation. Here, predominantly methanol is removed at temperatures at the bottom of up to 140° C. and pressures of from 1013 mbar absolute to 100 mbar over a period of one hour. The remaining bottoms (about 0.08% by weight of 1,6-hexanediol methyl adipate, 0.02% by weight of the di-1,6-hexanediol ester of adipic acid, 0.3% by weight of the 1,6-hexanediol ester of 6-hydroxycaproic acid) is fractionally distilled batchwise in a distillation column (1 m packed column, reflux ratio 5, no entry of air) at 100 mbar absolute and temperatures at the bottom of about 185° C. over a period of two hours. After removal of low boilers such as residual methanol and hexanol, 1,6-hexanediol is obtained in a distillation yield of about 90% with a purity of 99.9% and an N content of 1 ppm. The N content in the remaining bottom is 15 ppm.
Comparative Example 1
Example 1 is repeated with the difference that a second reactor which corresponds in terms of dimensions and capacity to the first and through which the reaction mixture flows after the first reactor is additionally installed in the hydrogenation. Accordingly, the space velocity over the catalyst decreases to 0.75. The conversion of dimethyl adipate was virtually quantitative, and the output comprised methanol and hexanediol together with 6-hydroxycaproic esters in the form of methyl and hexanediol esters in amounts of less than 0.03% by weight, about 0.6% by weight of hexanol, a balance in each case less than 0.05% by weight. The output again has an N content of 5 ppm. It is worked up further to give 1,6-hexanediol as in example 1. The resulting 1,6-hexanediol had an N content of 5 ppm, and the bottom product had an N content of 7 ppm. | The invention provides 1,6-hexanediol having a proportion by weight of nitrogen of less than 5 ppm, and polymers obtained by reacting the 1,6-hexanediol with at least one reactive compound. The 1,6-hexanediol is obtained by distilling a mixture including 1,6-hexanediol and more than 500 ppm of at least one carboxylic acid, ester, or both, having a boiling point higher than that of the 1,6-hexanediol and being in contact with the 1,6-hexanediol at a temperature range greater than or equal to 100° C. for at least 5 minutes before, during, or before and during, the distillation, followed by collection of the 1,6-hexanediol. In certain embodiments of this invention, the 1,6-hexanediol has a proportion by weight of nitrogen of less than 3 ppm and less than 2 ppm. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Claims priority to U.S. Provisional Application No. 61/227,923 “Strict-Sense Minimal Spanning Switch Non-Blocking Architecture,” originally filed Jul. 23, 2009.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO A SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention provides a method and apparatus for implementing a non-blocking minimal spanning switch.
2. Background of the Invention
Telecommunication systems require switching networks to transmit data signals, or messages, from one point of the network to another point of the network. Many systems often employ the Clos Network, a type of switch network, for data transfer. The Clos Network is a multi-stage switch network, where each stage consists of a crossbar or crossbar switch. The system can be arranged into three stages: the ingress stage; the middle stage; and the egress stage. A total of n inputs are allowed into the ingress stage, where n=the total number of data input signals which are transmitted into the total crossbar connections (r) of the ingress stage (or any other stage). The data input into the ingress stage is subsequently output from the ingress stage; a total of m outputs are allowed, where m=the total number of data output signals which are transmitted out of the ingress stage and m=the total number of crossbar connections located in the middle stage. One connection is provided to allow the data from the (n−1) data inputs of the ingress stage to be transmitted out of the ingress stage and into the middle stage, and one connection is provided to allow this data to be transmitted out of the middle stage and into the egress stage. The classic Clos Network switch fabric is illustrated in FIG. 7 .
Charles Clos further defines a Strict-Sense Non-Blocking Clos Network, where unused ingress crossbar connections are connected to unused egress crossbar connections, where m≧(2n−1). In a typical three stage Clos Network, to guarantee the connection of n connections, (2n−1) crossbar connections are required in the middle stage; with (n−1) data inputs active in the ingress stage crossbar connections, and another (n−1) data inputs potentially active in the egress stage crossbar connections, (2n−2) crossbar connections are required in the middle stage to allow the connection, where (n−1)+(n−1)=(2n−2). However, as (2n−2) crossbar connections may be unable to provide every necessary connection, an extra crossbar is provided to ensure Strict-Sense Non-Blocking, with (2n−1) middle stage crossbar connections.
(2n−1) middle stage crossbar connections would consume a large amount of resources, but in a Clos Network, m≧(2n−1) is necessary to maintain Strict-Sense Non-Blocking. When implementing a Clos Network which does not adhere to m≧(2n−1), the data connections may need to be re-routed in order to establish new connections, and such re-routing would result in interrupted or blocked connections, i.e., dropped telephone connections.
One method of minimizing the number of crossbar connections in the middle stage is through the use of a Non-Blocking Minimal Spanning Switch. When using a Non-Blocking Minimal Spanning Switch system, the connections between the ingress stage, middle stage and egress stage are symmetrical, with n ingress stage crossbar connections, n middle stage crossbar connections and n egress stage crossbar connections. This is achieved through the use of multiple sub-switches located in each stage; as an example a 4×4 switch including two input crossbar connections and two output crossbar connections are used. In a Non-Blocking Minimal Spanning Switch system, any data input signal input to any ingress location may be output from any egress location provided there is an open connection and an open path; however, signals can be blocked when they arrive from the ingress stage to the middle stage where the sub-switch locations are already in use, requiring other signals to be re-routed to ensure transmission. Such re-routing of signals is undesirable; the signals being transmitted are already carrying data, thus re-routing the data signal would again result in interrupted or blocked connections, i.e., dropped telephone connections.
Therefore, a method of re-routing the data signals transmitted through switching fabrics, without causing such interruptions, is required.
SUMMARY OF THE INVENTION
The present invention discloses a novel Strict-Sense Minimal Spanning Non-Blocking Architecture for use in frame-based data communications networks, providing the ability to re-route a telecommunications connection without interrupting the data signal. To maximize efficiency, the amount of logic duplicated on each data stream is minimized through the use of a n framer system, where n=the total number of framers in the system. In addition, n=the total number of data input signals which are transmitted into the crossbar connections (r) of the system. In the present invention, a “framer” refers to a machine which recognizes inherent framing patterns in transmitted data which occurs at predictable intervals. In the n framer system, each of the n bit streams enters n framers at a crossbar connection, and the n framers subsequently determine the inherent framing patterns within the transmitted data which are necessary for re-alignment. From these inherent framing patterns, the n framers can derive an arbitrary frame start signal, or the “start of frame.” The start of frame, as derived by the n framers, indicates to the n framers to write the transmitted data into a specific, but arbitrary location(s) of n buffers. These arbitrary locations of n buffers represent the offsetting bit location in each of the n buffers where the n framers are to start writing the transmitted data to allow the data to be written into the n buffers in a re-aligned fashion. A multiplexer can then read out the realigned data from the n buffers and select from any of the re-aligned data signals to provide a single data output signal. In an illustrative embodiment of the invention, the n incoming data input signals are transmitted to n framers, where each of the n incoming data input signals are divided into d data signals, where d can be any arbitrary and user-definable amount of data signals. This provides a total of x internal data signals, as n×d=x. The x internal data signals are then written into a specific, but arbitrary location(s) of x buffers. A multiplexer can then read out the realigned data from the x buffers and select one, single data output signal; i.e., each crossbar connection has one data output signal, therefore m crossbar connections have m data output signals. Through this method, each crossbar connection of the switch will output the exact same data in each of the m data output signals. Therefore, when any of m crossbar connections (where m=the total number of data output signals switches from one sub-switch to another sub-switch, no interruption occurs; as the data on each sub-switch within a crossbar connection is identical, any connection can be successfully used by the switch.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating four inputs and one output of a switch (prior art).
FIG. 2 is a block diagram illustrating the basic structure of a 4×4 switch (prior art).
FIG. 3 is a block diagram illustrating four data signals input into a 4×4 switch (prior art).
FIG. 4 is a block diagram illustrating four data inputs and one data output in accordance with an illustrative embodiment of the present invention.
FIG. 5 is a block diagram illustrating the internal circuitry of each sub-switch in accordance with an illustrative embodiment of the present invention.
FIG. 6 is a block diagram illustrating four data signals input to four crossbar connections and four data signals output from the four crossbar connections in accordance with an illustrative embodiment of the present invention.
FIG. 7 is a block diagram illustrating a simplified version of the classic Clos Network switch fabric (prior art).
DETAILED DESCRIPTION OF THE INVENTION
An illustrative embodiment of the invention employs a n framer system as applied to a 4×4 switch. The crossbar connections employed may be Field Programmable Gate Arrays (FPGAs) or any other logic circuitry element. It should be noted that this example is provided for illustrative purposes only and is not meant to limit the scope of the invention, as any size switch can be accommodated. In the 4×4 switch, each of the crossbar connections m has four separate data input locations and one single data output location. This is illustrated in FIG. 1 , where four data input signals A, B, C and D enter a single crossbar connection m( 1 ), where multiplexer ( 1 ) selects one of data input signals A, B, C and D and subsequently outputs the signal from the system through the single data output location; this is illustrated as data output signal W. As illustrated in FIG. 2 , the 4×4 switch is composed of four crossbar connections, m( 1 ), m( 2 ), m( 3 ) and m( 4 ). The input of the four data input signals A, B, C and D into the 4×4 switch is illustrated in FIG. 3 , where each of the four data input signals A, B, C and D are input into each of the four crossbar connections, m( 1 ), m( 2 ), m( 3 ) and m( 4 ); the four data input signals A, B, C and D transmitted into each of the four crossbar connections, m( 1 ), m( 2 ), m( 3 ) and m( 4 ) provides a total of 16 data inputs to the 4×4 switch. However, each of multiplexers 1 ( 1 ), 1 ( 2 ), 1 ( 3 ) and 1 ( 4 ), located in crossbar connections, m( 1 ), m( 2 ), m( 3 ) and m( 4 ), respectively, select from the four data inputs to provide one data output for each of crossbar connections m( 1 ), m( 2 ), m( 3 ) and m( 4 ), for a total of four data output signals, W, X, Y and Z. As illustrated in FIG. 3 , data output signal W is output from m( 1 ), data output signal X is output from m( 2 ), data output signal Y is output from m( 3 ), and data output signal Z is output from m( 4 ).
FIG. 4 provides an illustrative embodiment of the Strict-Sense Minimal Spanning Non-Blocking Architecture applied to a 4×4 switch system. As illustrated, each of data input signals A, B, C and D are fed into their respective data input locations of crossbar connection m( 1 ). Please note that each of data input signals A, B, C and D are likewise fed into respective data input locations of crossbar connections m( 2 ), m( 3 ) and m( 4 ), as the internal circuitry of the crossbar connection m( 1 ) is identical to the internal circuitry of m( 2 ), m( 3 ) and m( 4 ); thus FIG. 4 can be considered as representation of any of crossbar connections m. As illustrated in FIG. 4 , the data input to each of data input locations A, B, C and D enters one of framers ( 2 ). The framers ( 2 ) are able to recognize the start of frame, or the first byte of the frame. Framers ( 2 ) detect the start of frame in the incoming data by identifying the Frame Alignment Signal (FAS), an inherent and repeating framing pattern. With the start of frame known, the four data input signals A, B, C and D can be written into buffers ( 3 ) in a re-aligned fashion, writing the start of frame, or any other common starting byte, into a first common and specific location of each of buffers ( 3 ), despite any difference in the arrival times for each of data input signals A, B, C and D. Multiplexer 1 ( 1 ) can now read data out of a second common and specific location of each of buffers ( 3 ). Please note that these common first and second locations in each of buffers ( 3 ) can be any arbitrary and user-definable data locations. A pointer from multiplexer 1 ( 1 ) reads the re-aligned data out of the second common and specific location of each of buffers ( 3 ), ensuring that re-aligned and skew-free data is read from the buffers, despite any difference in arrival times between data input signals A, B, C and D. Multiplexer 1 ( 1 ) now selects from the data input signals A, B, C and D to provide a single data output, W.
The full 4×4 switch is illustrated in FIG. 6 , where the four data input signals A, B, C and D, are input into each of the four crossbar connections m( 1 ), m( 2 ), m( 3 ) and m( 4 ). Once the data is selected from the four input signals of each of the four crossbar connections m( 1 ), m( 2 ), m( 3 ) and m( 4 ) via the internal circuitry illustrated in FIG. 4 , one data signal is output from each of the four crossbar connections m( 1 ), m( 2 ), m( 3 ) and m( 4 ), for a total of four data signals output from the system. This is illustrated in FIG. 6 , where the four data output signals, W, X, Y and Z, are input into each of the four crossbar connections m( 1 ), m( 2 ), m( 3 ) and m( 4 ). Each of the data output signals, W, X, Y and Z will carry identical data, thus any of crossbar connections m( 1 ), m( 2 ), m( 3 ) or m( 4 ) may be chosen to make a connection.
DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT OF THE INVENTION
FIG. 5 illustrates a further illustrative embodiment of the present invention, employing a trunk framing system, where a trunk lane allows for one or more logical lanes in a single trunk lane. This illustrative embodiment of the invention is provided for illustrative purposes only and is not meant to limit the scope of the invention, as the invention may be applied to time switches or combinational space-time switches. The invention again employs a n framer system as applied to a 4×4 switch. The crossbar connections employed may be Field Programmable Gate Arrays (FPGAs) or any other logic circuitry element. It should be noted that this example is provided for illustrative purposes only and is not meant to limit the scope of the invention, as any size switch can be accommodated. As illustrated in FIG. 5 , trunk framers ( 7 ) receive the data input signals A, B, C and D, identify the start of frame, and therefore identify the frame alignment for each of data input signals A, B, C and D. With the framing pattern identified, de-multiplexers ( 8 ) divide each of trunk lanes A, B, C and D into four logical lanes ( 9 ), for a total of 16 logical lanes ( 9 ) in the system. Therefore, in a 4×4 switch, 64 logical lanes would exist within the 4 crossbar connections. As illustrated, with the start of frame known, each of the 16 logical lanes ( 9 ) within a single crossbar connection can be written into one of buffers ( 5 ) in a re-aligned fashion, with the start of frame, or any other common starting byte, written into a first common and specific location of each of buffers ( 5 ), despite any difference in the arrival times for each of the 16 logical lanes ( 9 ). The data from each of the logical lanes ( 9 ) remains buffered in buffers ( 5 ) until multiplexer ( 6 ) sends a pointer to each of the 16 buffers ( 5 ) to read data out of a second common and specific location of each of buffers ( 5 ). Again, this ensures that multiplexer ( 6 ) reads out re-aligned and skew-free data from each of buffers ( 6 ), despite any difference in arrival times between data input signals A, B, C and D, or any timing differences between logical lanes ( 9 ). Multiplexer ( 6 ) now selects from the 16 logical lanes ( 9 ) to provide a single data output, W.
Through using this Strict-Sense Minimal Spanning Non-Blocking Architecture, the present invention ensures that each of the four crossbar connections m( 1 ), m( 2 ), m( 3 ) and m( 4 ) output the exact same data in each of the four data output signals, W, X, Y and Z, respectively. Therefore, when the 4×4 switch switches from one of crossbar connections m( 1 ), m( 2 ), m( 3 ) or m( 4 ), to any other of crossbar connections m( 1 ), m( 2 ), m( 3 ) or m( 4 ), no interruption occurs; the data on each crossbar connection m( 1 ), m( 2 ), m( 3 ) and m( 4 ) is identical, thus any connection can be used for the switch. This allows for the use of a m=n Non-Blocking Minimal Spanning Switch, where n=the total number of data input signals and m=the total number of data output signals and m=the number of crossbar connections in each switch, while eliminating the possibility of data interrupts. | The present invention discloses an apparatus to implement a m=n Non-Blocking Minimal Spanning Switch, where n=the total number of data input signals and m=the total number of data output signals and m=the number of crossbar connections in each switch. Data is input to the switch as a plurality of frames, whereby each crossbar connection contains a framer which detects framing patterns in the data. Skewed data is re-aligned and buffered so that the data output by each crossbar connection is equal and identical, thus any crossbar connection may be used to ensure a connection, eliminating the possibility of data interrupts. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention generally relates to fluid treatment system distributor plates and, more particularly, to a distributor plate assembly including a secondary baffle plate positioned beneath the primary distributor plate of such a system.
2. Discussion of the Related Art
Water softeners are widely used for removing calcium and other deposit causing materials from so-called “hard-water.” The typical water softener relies on an ion exchanges process taking place in an ion-exchange resin bed stored in a resin tank or pressure vessel of the water softener. As the water to be processed passes through the resin-filled tank, ions of calcium and other minerals in the water are exchanged with ions found in the resin, e.g., sodium, thereby removing objectionable ions from the water and exchanging them for less objectionable ions from the resin.
The capacity of the resin to exchange ions is finite and is reduced during the ion exchange process. If measures are not taken to regenerate the resin by replacing the undesirable ions with desirable ions, the ion exchange capacity of the resin will become exhausted. Water softeners are typically configured to periodically regenerate the ion exchange resin stored in the resin tank. Regeneration typically involves chemically replacing the objectionable ions such as calcium ions from the resin with less objectionable ions such as sodium ions. The replacement is usually performed by introducing a regenerant solution of sodium chloride or potassium chloride into the resin bed from a brine tank and thereafter flushing the regenerant solution from the bed, i.e., brining. Regeneration of a water softener resin bed is sometimes accomplished in a direction that is co-current with the flow of water to be treated (often referred to as “downflow regeneration” or “service flow”) and is sometimes accomplished in a direction countercurrent to the flow of the water being treated (often referred to as “upflow regeneration” or “backwash flow”). The resin bed is typically backwashed in order to remove trapped particulate matter, and the resin tank can be rinsed to remove objectionable soluble materials. In order to prevent interruption of service, most water softeners are configured to allow bypass of untreated water directly to the service lines during backwash, rinse, and regeneration.
Resin tanks typically employ a distributor plate that allows water to flow through either a filter media bed or an ion exchange bed. Such distributor plates are configured to distribute flow as evenly as possible across the bed to ensure that the entirety of the bed is treated. However, such distributor plates do not operate as efficiently as is desired, particularly in resin tanks employing an upflow brining system. Upflow brining involves forcing water from the brine tank downward through a central riser tube to the bottom of the resin tank and then upward, i.e., upflow, through the distributor plate and the resin bed and out of the top of the tank.
During the brining operation, and particularly the brine draw operation where the brining solution is drawn up through the resin bed, gasses trapped in the fluid are disassociated and form bubbles, which float up through the distributor plate. The bubbles tend to float directly up near the centrally located riser tube and form channels through the resin bed media through which fluid tends to flow, effectively short circuiting the flow of brine past the media.
Further, after the brining process is complete, a slow rinse phase occurs, which is configured to remove excess brine from the resin bed. In the slow rinse phase, raw, untreated water (or, in some systems, treated water) is delivered to the lower end of the resin tank by the riser tube. However, as the rinse water exits bottom of the riser tube, it tends to immediately percolate up through the distributor plate along the riser tube rather than flowing out toward the edge of the tank. This concentrated flow near the riser tube results in the water being concentrated near the center of the tank, leading to insufficient rinsing of media located near the outer edge of the tank.
At least some of these issues are not unique to resin tanks of water conditioning system but, instead, are of a concern in a variety of fluid treatment systems in which a treatment medium is subject to brining.
The need therefore exists to provide a resin tank configured to more uniformly distribute water or other fluid across the entirety of the resin tank during a brining phase and/or a slow rinse phase of an upflow brining process.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the invention, a fluid treatment device is provided that includes a tank containing a bed of fluid treatment media and a fluid. A distributor plate is received in the tank and separates the bed from a lower end portion of the tank. A secondary plate or baffle is positioned beneath the distributor plate. The baffle is configured to direct a rinsing fluid delivered to the lower end around an edge of the baffle to improve flow distribution radially across the tank. The baffle may have a downwardly facing concave surface configured to trap air bubbles generated, for example, during the brining phase of a media regeneration cycle.
The baffle may extend radially approximately halfway between a hub of the distributor plate and an outer edge of the tank. The baffle may be positioned, relative to vertical, about halfway between a bottom of the tank and an underside of the distributor plate.
In accordance with another aspect of the invention, a method of operating a fluid treatment device comprises delivering a fluid to a lower end portion of a resin tank through a centrally located riser tube. The method further comprises diverting the fluid outwardly from the riser tube with a baffle positioned beneath the distributor plate to thereby distribute the fluid radially across the tank. The method may also comprise trapping air bubbles beneath a concave bottom surface of the baffle.
Various other features, embodiments and alternatives of the present invention will be made apparent from the following detailed description taken together with the drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration and not limitation. Many changes and modifications could be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings, in which like reference numerals represent like parts throughout, and in which:
FIG. 1 is a sectional side elevation view of a bottom portion of a pressure vessel according to the prior art and is appropriately labeled “PRIOR ART”;
FIG. 2 is a sectional side elevation view of a pressure vessel including a secondary plate according to an aspect of the present invention;
FIG. 3 is a sectional bottom plan view of the pressure vessel taken from beneath the secondary plate;
FIG. 4 is a sectional side elevation corresponding to FIG. 2 and additionally illustrating a guard coupled to the secondary plate; and
FIG. 5 is a partial sectional side elevation view showing the secondary plate and guard in additional detail.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and, initially, FIG. 1 , a prior art resin tank 10 used in a water treatment system (not shown). One of a variety of water treatment systems with which the resin tank 10 is usable is disclosed in U.S. Pat. No. 6,402,944, the contents which are incorporated herein by reference. The tank 10 includes a blow-molded plastic liner 33 reinforced by a layer 34 of fiberglass wrap or the like. The interior of the tank 10 contains a resin bed 12 separated from a lower end portion 14 of the tank 10 by a distributor plate 16 . The distributor plate 16 comprises a central hub 18 through which a distributor or riser tube 20 is securely received such that the distributor plate 16 is capable of supporting the riser tube 20 . The distributor plate 16 further includes an outer ring 22 , which is bonded to the interior wall of the resin tank liner 33 forming the outer edge of the tank 10 . A slotted plate 24 , supported by a number of reinforcing ribs 40 , is provided between the hub 18 and the outer ring 22 and is configured to allow water to pass through the distributor plate 16 between the resin bed 12 and the lower end portion 14 of the tank 10 . The distributor plate 16 may be integrally constructed from a plastic or similarly suitable material. The hub 18 defines a flange 25 which extends downwardly from an upper surface of the distributor plate 16 . The flange 25 may include a threaded portion 26 configured to engage a corresponding threaded portion 28 on the bottom 30 end of the riser tube 20 . An inlet tube 32 , positioned beneath the bottom end 30 of the riser tube 20 , extends downwardly through the distributor plate 16 in communication with the lower end portion 14 of the tank 10 .
As is generally understood in the art, in upflow brining, a brine solution is passed down the riser tube 20 to the lower end portion 14 of the resin tank 10 . The brine then flows upwardly through the distributor plate 16 and then through the resin bed 12 and eventually out of the resin tank 10 . Because the brine solution is heavier than water, the brine solution tends to puddle or pool underneath the distributor plate 16 . With the relatively low velocities involved with pushing the brine solution up through the distributor plate 16 and the resin bed 12 , a portion of the brine solution begins to puddle or pool underneath the distributor plate 16 after all of the brine solution has been delivered to the lower end portion 14 of the tank 10 . Further, during the delivery of the brine solution to the lower end portion 14 , gasses trapped in the water are disassociated and form air bubbles 39 . These bubbles 39 float up through the resin bed 12 and create channels along the riser tube 20 through which the brine solution may be preferentially directed, which thereby prevents or at least inhibits the brine solution from reaching the outer edge of the resin tank 10 .
After the brine solution is delivered to the resin bed 12 , the fluid treatment system operates in a so-called “slow rinse” phase of the water treatment cycle to clear any remaining brine solution from the resin tank 10 , typically using untreated or raw water, or in some cases treated water, both of which have a lower density than the brine remaining in the tank. Because the slow rinse water is less dense in prior art fluid treatment systems such as that shown in FIG. 1 , the water for the slow rinse phase begins to percolate directly upwardly near the distributor plate 16 almost immediately upon leaving the riser tube 20 and thus does not get evenly distributed across the radius of the resin tank 10 , thereby resulting in less effective or even ineffective rinsing of the resin in the outer portions of the tank.
In particular, as indicated by arrows 36 , during the slow rinse phase, water is introduced into the lower end portion 14 of the tank via the riser tube 20 and the inlet tube 32 . The water flows out of the end of tube 32 and, as indicated by the arrows 38 , immediately begins to rise nearly vertically upwardly near the distributor plate 16 . Thus, the water is heavily concentrated near the riser tube 20 as indicated by arrows 41 , resulting in an inefficient rinsing of the outer portion of the resin bed 12 . Even this flow is hindered by the “unrinsed brine” accumulated on the bottom of the tank during the brining operation as shown at 37 .
With reference now to FIGS. 2-3 , a resin tank 110 is shown in accordance with an embodiment of the invention. Resin tank 110 and the associated distributor plate 116 are of generally the same construction as the corresponding components of the prior art resin tank 10 of FIG. 1 except for the fact that a secondary plate or baffle 142 is provide beneath the primary distributor plate 116 . Since many of the structures and features of the resin tank 110 are identical to those of the resin tank 10 of FIG. 1 , the foregoing descriptions thereof apply equally unless otherwise indicated. The reference numerals of the structures of FIG. 1 are incremented by 100 in FIGS. 2-5 .
The secondary plate or baffle 142 is positioned vertically between the bottom surface of the tank 110 and distributor plate 116 . It may be mounted directly or indirectly on the hub 118 of the distributor plate 116 , the bottom of the tank 110 , or the tank liner 133 . It is indirectly mounted on the hub 118 in this embodiment by being coupled to the inlet tube 132 . Hence, the baffle 142 may be coupled to inlet tube 132 or may be integrally formed therewith as shown. At least the bottom surface 143 of the baffle 142 is concave so as to face downwardly. The baffle 142 may also include a mounting ring 150 integrally formed and extending from the bottom surface 143 thereof. The mounting ring 150 may be configured to receive an accessory as will be described in additional detail herein.
As will be explained in additional detail hereinafter, the distributor plate 116 may include a port 151 , which may be provided to allow an operator of the tank 110 to fill the lower end portion 114 of the tank 110 with an inert particulate media as discussed below.
The diameter of the baffle 142 is selected so as to position its circular outer edge 145 at a location that results in directing some fluid toward the outer edge of the tank 110 while still assuring that enough fluid flows up the inner portion of the resin bed 112 to achieve the desired relatively uniform flow throughout the radius of the resin bed 112 . The ideal baffle diameter will depend on a number of factors including, but not limited to, the density, viscosity, and flow rate of the fluid, as well as the vertical spacings between the baffle 142 and the bottom of the tank 110 and between the baffle 142 and the bottom of the distribution plate 116 . In a preferred construction of the baffle 142 , the outer edge 145 of the baffle 142 is positioned between 20% and 80%, more preferably 40% to 70%, and most preferably approximately halfway between the flange 125 of the hub 118 and outer edge of the tank 110 as defined by the inner surface of the liner 133 . Further, in a preferred construction of the baffle 142 , the concavity of the baffle 142 is sized to define a volume of sufficient size to accommodate a worst-case scenario with respect to the amount of bubbles 139 that may be formed during the brining process so as to be capable of at least substantially entirely capturing the bubbles 139 .
The baffle 142 may be spaced in any number of positions relative to vertical with respect to the distributor plate 116 . For a given baffle diameter, the nearer to the distributor plate 116 that the baffle 142 is positioned, the better the baffle 142 is able to trap the bubbles 139 , whereas the nearer to the bottom of the tank 110 the baffle is positioned, the better the baffle is at redirecting the water or fluid toward the outer edges of the tank 110 to better distribute the fluid from the slow rinse cycle evenly across the radius of the tank 110 . In the illustrated embodiment in which diameter of the baffle 142 is about half that of the tank 110 , the baffle 142 is positioned approximately halfway between the bottom of the distributor plate 116 and the bottom of the tank 110 .
In operation, during the slow rinse phase, the water is delivered to the lower end portion 114 of the tank via the riser tube 120 and the inlet tube 132 as indicated by the arrows 136 . However, unlike in the prior art systems, as the water exits the riser tube 120 , the water is forced outwardly toward the outer edge of the resin tank 110 as indicated by arrows 138 . As the water reaches the edge of the baffle 142 , it flows around the past the outer edge 145 of the baffle 42 . From there some of the water flows toward the riser tube 120 and the center of the resin tank 110 , and some is diverted toward the outer edge of the resin tank 110 as illustrated by arrows 152 . In this manner, the water used for the slow rinse cycle is more evenly distributed across the entire radius of the resin tank 110 as illustrated by arrows 141 and therefore is better able to entirely rinse the resin bed 112 of the brine solution. Further, as opposed to the prior art, the air bubbles 139 are caught underneath the baffle 142 and thus at least substantially prevented from floating up toward the distributor plate 116 , thus preventing the formation of a channel through the resin bed 112 through which the water or other fluid may flow. The bubbles 139 may then be subsequently removed during the so-called “fast rinse” phase of the water treatment cycle.
With reference now to FIGS. 4 and 5 , another embodiment of the present invention is illustrated. In the present embodiment, the structures of the tank 210 are identical to those of the first embodiment illustrated in FIGS. 2 and 3 unless otherwise indicated, and the structures are numbered as in FIGS. 2 and 3 and incremented by 100.
In the present embodiment, the distributor plate 216 and the baffle 242 are of identical construction to the corresponding components of the first embodiment. In addition, the lower end portion 214 of the tank 210 is filled with an inert media, generally shown as numeral 254 . The media may be introduced to the lower end portion 214 via the port 251 in the distributor plate 216 corresponding to the port 151 of the first embodiment (see FIG. 3 ) after installation of the plates 216 , 242 and related components into the tank 210 . Alternatively the inert media may be inserted prior to installation of the plates 216 , 242 and related components. In either case the case, the port 251 is plugged after insertion of the inert media to prevent unwanted matter from moving through the distributor plate 216 in either direction.
Preferably, substantially the entirety of the volume of the tank 210 beneath the distributor plate 216 is filled with the inert media 254 in order to minimize the volume where brine will be trapped during operation. Accordingly, the inert media may be either heavier than or lighter than the fluid of the fluid treatment tank. The inert media 254 is preferably granular and may be in the form any or all of gravel, polypropylene beads, polyethylene beads, etc. The inert media 254 thereby minimizes and reduces the void volume beneath the bottom the distributor plate 216 . Since the volumetric flow rate of rinse water is the same (typically about 2.5 gallons per minute) whether or not the inert media is present in the bottom portion of the tank, the presence of the media causes the rinse water through flow in the bottom portion 214 of the tank 210 at a higher velocity, improving the flushing of unrinsed brine from the bottom portion 214 of the tank 210 and improving the rinse phase overall.
A guard 256 may be coupled to the mounting ring 250 of the baffle 242 . The guard 256 is configured to protect the bottom of the inlet tube 232 from the ingress and egress of the inert material 254 during operation. The guard 256 may be sized and shaped in any manner so long as the guard 256 is capable of preventing the intrusion of the inert media 254 . As illustrated, the guard 256 is generally frusto-conically shaped and includes a relatively flat bottom 258 , a circumferential sidewall 260 having a plurality of apertures, holes, or other such openings 262 to allow for fluid flow therethrough, and a flanged upper end 264 , which is configured to be coupled with the mounting ring 250 . The openings 262 of the guard 256 preferably are sized and shaped to prevent the inert media 254 from entering the guard 256 and, thereby, the inlet tube 232 and the riser tube 220 . The guard 256 may be integrally molded with the mounting ring 250 or connected to the mounting ring 250 by any other suitable mechanism.
Although the best mode contemplated by the inventors of carrying out the present invention is disclosed above, practice of the present invention is not limited thereto. It will be manifest that various additions, modifications and rearrangements of the aspects and features of the present invention may be made in addition to those described above without deviating from the spirit and scope of the underlying inventive concept. The scope of some of these changes is discussed above. The scope of other changes to the described embodiments that fall within the present invention but that are not specifically discussed above will become apparent from the appended claims and other attachments. | A fluid treatment device includes a tank containing a fluid treatment medium and a fluid. A distributor plate is received in the tank and separates the bed from a lower end portion of the tank. A baffle is positioned beneath the distributor plate and is configured to direct fluid exiting a riser tube of the fluid treatment device toward the peripheral of the tank to thereby provide a more evenly-distributed flow through the radius of the distributor plate and through the fluid treatment medium. The baffle may have a downwardly facing concave surface that traps air bubbles generated during a brine draw operation. | 1 |
This invention is a continuation-in-part of my copending prior application Ser. No. 782,886, filed Mar. 30, 1977 and now abandoned.
Background
This invention relates to energy conversion devices in general and is particularly concerned with a prime mover adapted for efficiently harnessing the kinetic energy in ocean waves.
The continued growth of the industrial nations has placed an ever increasing burden upon world energy supplies. It is now apparent that traditional sources of energy will be adequate to meet the world energy needs for only a relatively short time. In particular, the unreplenishable fossil fuels are being depleted at an ever-increasing rate, especially in industrialized nations. Virtually every credible energy study made in recent years reaches the conclusion that conventional energy supplies will be essentially exhausted in the near future unless new sources of energy are found.
Accordingly, there is an immediate, extremely critical need for development of alternate sources of energy. Various proposals for utilizing new energy sources, ranging from promising to ridiculous, have been set forth in an effort to meet the impending world-wide crisis. Almost without exception, the proposed sources of new energy present one or more serious drawbacks to their use in the foreseeable future. Many proposed sources are simply environmentally unacceptable, while others are so technically sophisticated that many years of research and development are required before they can be considered a practical alternative to conventional energy supplies. Still other new energy proposals, while not detrimental to the environment and while within the scope of our present technology, are so expensive as to render them economically infeasible at the present time.
Hence, there is clearly a demand for a source of clean, environmentally acceptable and relatively inexpensive supply of energy. One such source which has heretofore been underdeveloped is the tremendous amount of energy contained in surface water waves. While many efforts have been made to utilize water wave energy, almost all have been unsuccessful because of a failure to amplify unitized wave energy and to protect equipment from destructive wave forces. Such energy has for centuries virtually gone unused in continuous pounding of the waves along thousands of mile of shorelines, while often only miles inland scientists and inventors struggled with the perplexing problem of satisfying world energy needs. Hence, even in our highly technical, energy starved society, little progress has been made in efficiently harnessing the energy of oceanic waves.
Many of the ocean wave energy systems involve highly complex structure and are still in the initial experimental stage. One exception is the device disclosed in U.S. Pat. No. 1,498,707 issued to Wilcott. This patent shows a wave-powered water motor but fails to adequately consider such practical problems as required torque conversion, operation under storm conditions and optimal rotor positioning. Thus, the Wilcott device does not make provision for amplification of unitary wave energy nor does it have adequate protection from wave damage in storm conditions.
SUMMARY OF THE INVENTION
In an effort to overcome the aforementioned problems, the prime mover of the present invention comprises a series of bladed rotors adapted to be supported in wave-receiving relation over a body of water and having a hydraulic lift for positive height adjustment of the rotors in response to changing wave conditions. A planetary gear assembly between each rotor and the drive shaft of the prime mover accomplishes torque conversion in a desired manner such that the shaft is continuously rotated at the required speed notwithstanding the fact that the individual rotors are themselves only intermittently subjected to wave impact and accordingly revolve at a slower speed.
In preferred forms, a computerized controller is coupled with the lift assembly and receives input from electronic wave height sensors positioned on the ocean floor for the purpose of automatically adjusting the elevation of the rotors in response to the height of the incoming waves. In this manner, the rotors can be at all times positioned to receive the more effective driving force found in the upper portion or crest of a wave, and further, there is precluded undesired breaking of waves over the rotors with resultant structural damage or loss of efficiency to the prime mover.
There is also disclosed an alternate embodiment having a wave diverter capable of intercepting large maverick waves and directing the latter downwardly for additional driving impact against a rotor disposed therebelow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary front elevational view of a wave powered prime mover constructed in accordance with the principles of the present invention;
FIG. 2 is an enlarged, side elevational view;
FIG. 3 is an enlarged, fragmentary plan view;
FIG. 4 is an enlarged, fragmentary cross-sectional view of the planetary gear assembly;
FIG. 5 is an enlarged, cross-sectional view taken along line 5--5 of FIG. 4;
FIG. 6 is a schematic diagram illustrating the automatic rotor elevation control system;
FIG. 7 is an enlarged, side elevational view of a second embodiment of the present invention; and
FIG. 8 is a front elevational view of the embodiment shown in FIG. 7.
DETAILED DESCRIPTION
In FIGS. 1-5 there is shown an oceanic wave powered prime mover 10 comprising stationary structure in the form of a number of spaced upright pylons 12 secured in the floor of a body of water and projecting above the surface S of the latter, a generally horizontal elongate drive shaft 14 shiftably supported on the pylons 12 for up and down movement toward and away from the surface S, and a number of bladed rotors 16 coaxially carried on the shaft 14 and operably coupled therewith for driving the latter in response to wave movement past the pylons 12. Though not shown, it is contemplated that the output from shaft 14 could be utilized to mechanically power a large electric generator or the like.
Each rotor 16 comprises a central hub 18 and six radially extending blades 20 mounted in circumferentially spaced relation on the hub 18. As shown in FIGS. 1 and 2, the longitudinal axes of the blades 20 extend parallel to the shaft 14 and each blade 20 has a concavo-convex cross section tapering from the hub 18 to an edge 22 at the outer extremity of the blade 20. The curvature of the blades is hydrodynamically engineered to direct the thrust of the wave to the structurally reinforced load-bearing portion at the lower half of the blade adjacent the hub 18. A number of annular bands 24 circumscribe each rotor 16 innerconnecting the edges 22 for the purpose of increasing the rigidity of the rotors 16.
Each pylon 12 has an elongate arm 26 pivotally mounted thereon for up and down swinging movement about a generally horizontally extending trunnion 28. The trunnions 28 are disposed intermediate the ends of the arms 26, one end of each arm 26 supporting a planetary gear assembly 30 which is in turn coupled to the shaft 14 and a respective rotor 16. The opposite end of each arm 26 supports a generally horizontally extending beam 32 upon which are carried a plurality of counterweights 34 for the purpose of facilitating swinging of the arm 26 in a direction to raise the rotor 16.
Lift means in the form of a hydraulic cylinder assembly 36 for each arm 26 is provided to accomplish selective movement of the latter and desired positioning of the rotors 16. As shown in FIG. 2, the cylinder assemblies 36 are each mounted in a manner to extend between an arm 26 and the top end of a respective pylon 12 such that retraction and extension of the assemblies 36 causes up and down movement of the rotors 16. Though not shown, it is to be understood that the assemblies 36 are actuated by a common hydraulic system for in unison movement of the arms 26 and simultaneous shifting of the rotors 16.
Considering now FIGS. 4 and 5, there is illustrated the details of construction of the plantary gear assemblies 30. Each gear assembly 30 comprises a housing 38 rigidly mounted to a respective arm 26 and having formed therein a ring gear 40 circumscribing the shaft 14. Three planet gears 42 are carried by a spider member 44 in mating engagement with the ring gear 40. As shown in FIG. 4, the spider member 44 is rigidly coupled with the hub 18 of a respective rotor 16 for rotation therewith. Finally, a sun gear 46 keyed to the shaft 14 is disposed in mating engagement with the planet gears 42 whereby the latter are caused to orbit around the gear 46 upon rotation of the rotor 16. Note that the arrangement and size of the gears 40, 42 and 46 are such that the angular velocity of the rotor 16 is stepped-up in order to obtain the desired angular velocity of the shaft 14. In actual practice, it has been determined that a step-up ratio of 30 to 1 may be required in order to impart the desired angular speed to the shaft 14; of course, it may be necessary to utilize two or more planetary gears 30 in tandem to accommodate stresses and accomplish the desired speed ratio. Further, it is contemplated that an override clutch will be contained in each gear assembly 30 in order to lessen shock forces on the shaft 14 and to permit most efficient utilization of wave energy.
A computerized control for the hydraulic cylinder assemblies 36 is shown diagramatically in FIG. 6. A number of electronic wave height sensors positioned on the ocean floor monitor the height of incoming waves and transmit this information to a computer or central controller. The central controller compares this information with data received from rotor elevation sensors mounted on the rotors 16 and sends appropriate signals to a hydraulic lift control to extend or retract the cylinder assemblies 36 as required in order to position the rotors 16 at the optimum height for receiving the incoming waves. Thus, the rotors 16 are continuously raised and lowered in response to changing wave conditions whereby to maximize the efficiency of the prime mover 10. Though the height control system for the rotors 16 is itself unique, it is noted that all of the basic components of the system are commercially available, as for example from Marines Systems Division of Honeywell, Inc., Seattle, Wa.
An alternate embodiment of the present invention is shown in FIGS. 7 and 8 comprising a prime mover 50 including a plurality of rotors 16, planetary gear assemblies 30, and a drive shaft 14, as found in the prime mover 10. Additionally, the prime mover 50 is provided with a number of upright pylons 52, analogous to pylons 12 but extending a greater distance above the surface S of the body of water, and a plurality of linkage assemblies 54 pivotally mounting respective rotors 16 and the shaft 14 on the pylons 52 for up and down movement.
Each linkage assembly 54 comprises an arm 26 pivotally secured to a pylon 52 by a trunnion 28 and supporting a counterweight 34, a second arm 56 pivotally secured to the pylon 52 at a point spaced above the trunnion 28, and an elongate bar 58 interconnecting the arms 56 and 26 to form a four bar parallel linkage as shown for example in FIG. 7.
The lowermost end of each bar 58 supports a respective planetary gear assembly 30 in the manner shown and there is mounted on the bar 58 a wave diverter 60 in overlying relation to the rotor 16.
The diverter 60 is a substantially upright panel presenting an arcuate, out-turned uppermost margin 62 and a lowermost funnel-like structure 64 adapted to direct water downwardly toward the rotor 16. It is contemplated that wave diverters 60 may be employed to harness maverick waves of significantly greater dimension than the mean wave height without requiring excessive up and down movement of the rotors 16. In this connection, the rotors 16 of prime mover 50 are normally not raised to receive large maverick waves, but rather, the latter are intercepted by the deflectors 60 and directed downwardly through the funnel-like structures 64 to impart a driving force on respective rotors 16. It is important to note that inasmuch as the wave diverters 60 are mounted directly on bars 58, the diverters 60 move up and down with the rotors 16 such that the structures 64 are always properly positioned relative to the latter.
A hydraulic cylinder assembly 66 is mounted between each pylon 52 and its respective second arm 56 to provide powered shifting of the linkages 54 and consequent up and down movement of the rotors 16. Cylinder assemblies 66 are actuated by a single hydraulic system similar to the actuating system for cylinder assemblies 36.
Operation of the prime movers 10 and 50 is apparent from the foregoing detailed description. In the case of prime mover 10, incoming waves on surface S are intercepted by the blades 20 of rotors 16 such that rotary movement is imparted to the shaft 14 through the planetary gear assemblies 30. The rotary movement of the shaft 14 may have any number of beneficial applications such as for example driving a large electric generator. In this latter regard, note that the planetary gears 30 including their override clutch feature permit continuous high speed rotation of the shaft 14 notwithstanding the fact that waves are only intermittently intercepted by the individual rotors 16.
During operation of the prime mover 10, it is desirable to maintain the rotors 16 at an optimum wave intercepting height in order to derive maximum operating efficiency. Preferably, the height of rotors 16 is adjusted such that each wave is intercepted by only the lower portion of the rotor 16. Manifestly, the wave height is not uniform but varies from wave to wave, and consequently, it is necessary to adjust the height of the rotors 16 in response to changes in the height of the incoming waves. This desired continuous height adjustment for the rotors 16 is accomplished by the lift control system shown diagramatically in FIG. 6.
Raising of the rotors 16 is facilitated by the provision of counterweights 34 which substantially balance the force moments about trunnion 28. Hence, only a relatively small force need be exerted by the cylinder 36 in order to accomplish movement of the arm 26 in a direction to raise the rotor 16. Of course, under storm conditions, it may be desirable to operate cylinder 36 in such a manner as to raise the rotors 16 a maximum distance above surface S until normal surf conditions return.
The operation of prime mover 50 is substantially the same as that of prime mover 10 with the exception that the rotors 16 are not raised in response to maverick waves with which exceed the mean wave height by a predetermined dimension. When such waves are encountered, the rotors 16 remain at their normal operating position, the diverters 60 serving to deflect the maverick wave in a manner to drive the rotor 16 as explained hereinabove.
From the foregoing, it can be seen that the present invention offers unique means for efficiently harnessing the energy in oceanic waves. The provision of planetary gears 30 assures rotation of shaft 14 at a speed which is practical for operation of electrical generators or the like, the override clutch feature protecting against undesirable drag and severe impact on the shaft 14 by the rotors 16.
The hydraulic cylinders 36 accomplish positive height control for the rotors 16 while at the same time permitting implementation of automatic rotor elevaton control. In this latter regard, the automatic lift control system disclosed contemplates continuous adjustment of the height of rotors 16 in response to changing wave conditions such that the prime movers 10, 50 operate at maximum efficiency. | A prime mover has a number of bladed rotors supported on a drive shaft over the surface of a wave-generating body of water for rotating the shafts by action of waves against the rotors. Unique planetary gearing assemblies coupling each rotor to the shaft provide necessary torque conversion for rotating the shaft at the desired speed. In preferred forms, the drive shaft is shiftably supported on a plurality of stationary pylons for up and down movement relative to the surface of the water through the action of a hydraulic lift assembly. A bank of wave height sensors is coupled to a computerized control for the lift assembly to adjust the position of the rotors in response to changes in wave height whereby the prime mover operates at maximum efficiency under the prevailing surf conditions. | 8 |
FIELD OF THE INVENTION
The present invention relates to methods for estimating risk of damage that is likely to be sustained by a structure from a physical disturbance. Specifically, the present invention provides a method for inspecting and determining the structural integrity of wood frame residential structures relative to earthquake shaking and wind forces acting upon such structures, and for quantifying the potential risk of such structure sustaining damages from such forces.
BACKGROUND OF THE INVENTION
Wood frame structures (especially those used for residential purposes) have long sustained significant amounts of damage due to physical disturbances accompanying "natural disasters" such as earthquakes and wind forces (hurricanes, tornadoes, nor'easters etc.). Due to the frequency of such events and the amount of damage which they can inflict on residential communities, damage risk assessment is an important consideration and priority for homeowners, lending, insurance and real estate industries, damage relief organizations and governmental agencies. Accurate prediction of such natural disasters has proven to be ineffective in most cases.
This leaves the burden of damage risk assessment to an analysis of the structural condition of a given home and how the structure would react to the varying stresses from physical disturbances experienced during earthquake shaking and high wind events. To date, such risk assessments have been made in two ways: (1) solely based on a subjective, onsite inspection analysis; or (2) solely based on a group "aggregate" comparison and evaluation of similar homes in the general geographic location as the structure in question.
In the first approach, engineers, architects and other technical specialists consider each home as an individual "project." Due to the fact that the specialist employed usually deals with a small number of exhaustive analyses, the time it takes for a risk assessment is great, ranging from weeks to months. Furthermore, due to the time and character of the report produced, this style of risk assessment can cost on the order of thousands of dollars. An onsite inspection by a technical specialist with a subsequent report and analysis is thus a process which is cost prohibitive for the average home owner or buyer. It also is a process which is not conducive to mass production, as each technical specialist works on a case by case basis, usually doing every part of the assessment themselves. In addition, conflicting standards used by such specialists in performing their inspections and analyses often results in inconsistent and unreliable data and conclusions that are difficult to interpret and of uncertain value to the entities listed above. Furthermore, such specialists have not been known to use (or have the facilities to use) geologic data and wind data specific to the site of the structure (such as the frequency, intensity, and proximity of earthquake faults), and thus are not able to consider this crucial element of the risk assessment process.
The second approach above can be seen to be even more unreliable and unusable, since it does not even include a direct observation of the specific characteristics of the structure in question.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of this invention to provide a method for accurately and reliably classifying wood frame structures (such as residential homes) for purposes of defining the potential risk level and damage that may be caused by physical disturbances, such as may be caused by earthquake or wind forces. As used herein, "physical disturbances" generally refers to seismic, wind, flood, tornado and other similar forces which might have a deleterious effect on the physical integrity of a wood frame structure.
A further objective of this invention is to provide a method of home risk analysis which can be inexpensively performed and thus made available to a larger number of potential users.
It is another objective of this invention to provide a useful diagnostic process for inspecting and evaluating wood frame structures that can be used to detect significant flaws in such structures, and for recommending corrections to such structures to reduce risk of damage from occurrences of the aforementioned physical disturbances.
The above objectives are accomplished by the method of the present invention, which estimates risk of damage likely to be sustained by a wood frame structure located at a particular site from a physical disturbance such as a wind storm or earthquake. The method generally includes the following steps: first, an inspection is made onsite to determine and collect structural characteristics data of the structure's frame and related physical data. This data is input into a database usable by a probabilistic engine computer program. This program generates an estimate of the risk of damage to the structure, based on a combination of the structure data and wind storm or earthquake database related information for the area where the structure is located.
The structural characteristics data collected can include data relating to the structure's frame, openings, supporting walls, foundation, cripple wall, roof and "soft" stories. Building code data and empirical damage historical data for such structure is also incorporated to refine the risk estimate.
An earthquake force specific risk report can be generated based on the structural characteristics data, and available seismic database information such as USQUAKE, which takes into consideration earthquake information related to the vicinity of the structure, such as probable type and size, recurrences and other geologic conditions. Similarly, a wind force specific risk assessment report can be generated based on the structural characteristics data, and available wind force database information such as USWIND, which takes into consideration information such as probable type and size of storms in the vicinity of the site.
The resulting report includes an overall rating for such structure that can be used for actuarial purposes. Additional information on defects detected in the structure, and recommendations for curing such defects is also included. The prediction or rating is also used by a homeowner as an evaluation factor in his/her decision to strengthen the structure against earthquake and/or wind storm damage. Government agencies and other entities can also utilize the risk assessment and information for many other uses such as but not limited to: disaster relief decisions, emergency planning, population displacement planning, etc.
By using a standard, uniform set of structural characteristics and available seismic and wind force database technology, the present invention permits inexpensive risk assessment that can be made more widely available to a larger percentage of the population. Further unlike prior art methods, the present report and rating can be generated within days of an onsite inspection. These factors make the present risk assessment process significantly more affordable in cost than a specially hired engineer, architect or other technical specialist.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram generally depicting steps employed in the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Single family wood frame homes are the most prevalent construction type in North America and other locations around the world. Windstorms, earthquake shaking and flooding are the most common natural hazards that damage and cause destruction to such structures. Earthquake shaking and windstorms are similar in nature relative to how they cause damage to wood frame structures. A structure is shaken and stressed by both of these natural events. A high percentage of damage that occurs to wood frame structures during shaking events is due to common design and construction flaws. By identifying these critical design aspects and assessing types of stress inducing events a structure may experience (such as may be obtained from available earthquake and wind databases), a reliable, inexpensive and quantified risk determination can be obtained. This risk determination can be converted into a standardized "rating" that can be used by homeowners, insurance companies, etc.
The risk evaluation method of the present invention is depicted generally by the flow diagram of FIG. 1.
A wood frame structure first undergoes an onsite inspection 10 to detect defects and flaws. The onsite inspection is preferably done by a person trained and qualified to detect structural and construction defects. While a professional inspector is preferred in order to increase the accuracy of the inspection, any person who has significant practical field experience in examining various aspects of home structure and design aspects (and who can collect sufficient information for a risk evaluation program described below) can perform onsite inspection 10.
Structural characteristics data 20 and other related data for the structure are collected and compiled by an inspector or other suitably trained person. A standardized set of parameters and information is collected in all cases to promote uniformity and reliability. In general, structural characteristics data 20 collected is based on knowledge and information provided by structural engineers of ordinary skill in the art, and includes provisions for ascertaining characteristics of structures important in evaluating their probable performance when stressed by natural forces such as earthquake shaking and wind storms. Structural data considered by home inspection business practitioners and others skilled in this art to be important to risk assessment evaluations is also preferably collected.
The structural characteristics data collected primarily includes data pertaining to typically weak elements of wood frame structures that are known (i.e., such as from standard design/modelling information, or empirical analyses of earthquake and storm damage to such structures) to be critical elements associated with damage. As is apparent, the information collected below is specific to wood frame structures. It will be evident to those skilled in the art, however, that the present invention could be applied in a similar manner to structures constructed of masonry, adobe, concrete block, or other such materials.
In a preferred embodiment, the present invention is used to analyze structures up to three stories in height, and less than 5000 square feet. On a broad level, information concerning general design characteristics of the wood frame structure are collected, including such things as building height (number of stories), approximate size of living space (square feet), general dimensions, including total length of front-facing walls, and total length of left or right facing walls. Primary exterior finishes are also determined, as well as obvious major defects in structural framing, bracing or foundation systems (e.g., dry-rot, deterioration, critical corrosion) as might be observed in any bracing system, the existence and prevalence of wood studs and sill plates (or their nailing and anchors), floor joist and beam systems, and perimeter foundation concrete defects. General architecture features (i.e., ceiling heights, room proportions, etc.) are also examined, along with the vertical configuration of the structure (i.e, whether exterior walls extend to the foundation). In addition, building plan layouts, slope of building pads, the existence and nature of any chimneys, and roofing information (roof materials, number of layers, roof decking materials) are also considered.
More specific information on walls of the structure is also collected, such as total wall length that is uninterrupted by doors, windows or other openings for each floor, and relative strengths of walls on any particular floor. This aspect of design is one which has been regularly recognized by those skilled in the art as a critical element of design relative to earthquake-induced shaking damage. It is advantageous to determine not only the length of walls, but the relative strength which they lend to the structure as a whole. For example, a solid wall is regarded as "stronger" than a wall which is interrupted by a large sliding glass door.
Specific details of foundation materials and anchorage are also inspected and collected, including perimeter foundation type, type of anchorage to the foundation, and age, size and spacings of anchor bolts or other anchoring mechanism. Again, this is an aspect of design which is empirically associated with damage sustained by earthquake shaking. If a structure is on a sub-standard foundation, such as an old brick foundation, damage can be experienced if the foundation fails. More commonly, if the structure is not properly anchored to the foundation, damage can be sustained during earthquake shaking if the structure is shaken off (or wind-lifted off) its foundation.
The most common design aspect associated with earthquake shaking, cripple wall design, is also examined. A cripple wall is a wall which connects the house structure to the foundation and elevates it to provide a crawl space beneath the house. If a cripple wall is weak, not properly braced, or braced with weak materials and/or incorrect fastenings, there is an empirically proven high rate of damage to the structure from earthquake forces. The cripple wall is susceptible to failure due to a high amount of shear stress exerted upon it during earthquake shaking. Failure of the cripple wall causes the structure to "fall" off the foundation and often experience further damage due to bouncing, distortion and impact. Thus, information is also collected concerning the cripple wall (existence, type, coverage, age) and related structures (perimeter cripple-wall studs, diagonal braces, exterior and interior bracing panel size, distribution and coverage, hold-downs & fasteners (and defects)). Furthermore, the quality of any bracing, including whether panels are fully nailed and supported at all edges, and nail spacing is noted. Framing clips in cripple-wall or rim joist systems are also examined.
Finally, the onsite inspection also evaluates the possible existence of "soft stories," a living area which is located above incomplete or structurally inadequate support walls. This typically refers to a living area over a garage. A garage door wall, due to the fact of the large interruption represented by the door, is not typically an adequate support wall. Thus, information concerning whether the garage is attached to the primary structure, whether there is a living space over garage, the number of side-by-side parking spaces in any garage, and total length of solid wall in line with any garage door opening is also collected.
The year of original construction of the structure is also ascertained, and from this, applicable building codes associated with the structure can be determined. Such codes also can be correlated in some instances to empirical rates of damage in earthquakes or storms for homes of similar age.
These are but examples of what information can be collected, and it will be apparent to those skilled in the art that additional or lesser data can be used as needed or desired. For an inspection designed to evaluate risk of wind damage, for example, appropriate structural information relating to wind forces would be collected. In addition to the above list, for example, this could include information on windows (size and location) and roofs (type, overhangs and shape).
After the structure is inspected, and the structural characteristics data 20 is collected, this information is input to a risk evaluation program at step 30 for analysis. In a preferred embodiment, the information is digitized and entered into a GIS (Geographic Information Systems) database containing a probabilistic program that has been specifically designed to evaluate and determine the relative risk of a given structure, specific to its location and other factors, when subjected to shaking and stresses of earthquake shaking or wind forces, as indicated by databases for geologic data 33 and wind data 36 respectively. In a preferred embodiment, the specific databases used by program 30 include USQUAKE and USWIND. USQUAKE and USWIND are both available database-probabilistic-software engine programs designed by EQE International of San Francisco, Calif. The above programs are examples of a type of database related software that is becoming more and more useful to insurance and reinsurance industries to evaluate portfolios of insurance policies for actuarial purposes. In addition, lenders of all types are starting to utilize this type of database and related software in their loss reduction and risk analysis efforts.
USQUAKE, and similar database-probabilistic-programs contain GIS databases, normal type databases and sophisticated engineering analyses which can evaluate a number of parameters in determining the relative risk of damage to a structure. In a preferred embodiment of the present invention, such programs are used to consider such parameters as: 1! distance to earthquake faults; 2! probable type and size of earthquakes; 3! earthquake recurrence intervals; 4! building code that the structure was built under; 5! type of construction used; 6! geology of area where the structure is located; and 7! empirical damage rates. Thus, such databases can include geologic, geographic, demographic and regulatory information. Similar types of information are utilized for a wind related analysis.
The above parameters are considered because (correlating to the above): 1! It is generally accepted that earthquake shaking intensity decreases with distance from the causative fault. Since most faults rupture along a line (linearly) it follows that the perpendicular distance from the causative fault is a prime factor in damage analyses; 2! Although the magnitude or size of an earthquake is of paramount importance to the amount of damage it can cause, it is also very important what type of earthquake rupture occurs. A seismograph recording of earthquakes records its character and this information can be considered in combination with historic earthquakes on each possible causative fault in order to evaluate the most probable size and most probable type of earthquake that is likely to effect a given structure; 3! The recurrence interval of earthquakes on a given fault is an important factor that is preferably evaluated relative to probable effect on a given structure; 4! Building codes that govern design of structures and construction practices have changed significantly over the years since 1950. In general, requirements for strengthening against earthquakes and wind storms has increased with each new building code. Which building code under which a specific structure was designed and built is a very important factor when evaluating risk; 5! Wood frame, one to three story structures are considered generally to be most earthquake resistant. When an individual structure varies from this ideal, risk of damage also increases; 6! Shaking characteristics of an earthquake are maintained or modified by geologic structure and geologic materials. Certain geologic structures can reflect or deflect shaking energy. In general softer geologic materials increase the shaking amplitude while decreasing its frequency thereby causing more violent shaking of structures which increases the risk to damage. 7! Damage to a specific structure can also be estimated by empirical comparison to how similar structures performed in shaking or wind events in the past.
A probabilistic software engine program 30 therefore utilizes the above parameters and evaluates the likelihood of various types of damage occurring and the probable monetary value (cost) of the likely damage for a given set of conditions. In these type of probabilistic calculations, accuracy improves significantly when a large number of individual properties are evaluated in this way. Accordingly, the present invention has an additional advantage in that the reliability of results obtained should improve with time. It can be see also that the inclusion of detailed site specific information results in a higher degree of reliability of probability quantifications than is attained than that allowed by group portfolio analyses alone.
Geologic/seismic database 33 (and/or wind force database 36) information and structural data 20 retrieved from the onsite inspection are combined by probability calculation program 30 for a given structure. Structural data 20 collected serves to define parameters of the structural design as it modifies probabilistic analysis of the structure. The physical disturbance database (geologic/seismic and/or wind force) information serves to define parameters of the likely stresses, empirical failure rates and the geographic and demographic characteristics for a given structure. It will be appreciated by those skilled in the art that other programs 30 can be substituted to perform the above analysis, subject only to the constraint that they be capable of correlating structural data 20 collected at the onsite inspection, with a preexisting geologic database 33 and/or wind database 36 (which also include geographic, demographic and regulatory information as noted above).
After the analysis is completed, a report 40 is generated. Report 40 can include a rating indicating whether the structure has a high or low probability of damage due to the stresses expected. An unfavorable, or low rating can be given to a structure which is given a higher probability of damage due to expected stress characteristics. Report 40 also fully describes the findings and reasons for any given rating.
The rating and report can be used for actuarial purposes by insurance carriers. For example, such carriers may decide to give structures getting a favorable rating much lower insurance rates. The report also includes information on the defects and flaws in such structure, and how to strengthen such structures against damage causing events. Many structures that initially obtain an unfavorable rating can undergo a retrofitting step 50 to permit an optional re-inspection as shown in FIG. 1. This mechanism provides residential homeowners with incentives to strengthen their homes because a higher rating may be obtained from a subsequent re-evaluation.
Furthermore, it is apparent that after a structure has been inspected once, and retrofitting has been done to such structure, the necessity and cost of another complete actual on-site inspection can usually be avoided. Thus, only the retrofitting portions of the inspection would be repeated if it appears that there is no reasonable basis for concluding that (other than the retrofitting) substantial changes need to be made in the original collected structural data. If the original collected structural data is preserved in permanent electronic form usable by program 40, the necessity for another complete onsite inspection can even be avoided.
One beneficial consequence of using the present invention therefore is a structurally upgraded and more sound housing stock. In all cases, regardless of retrofitting or insurance eventualities, homeowners are made aware of the risk level of their home being damaged by earthquake shaking or wind forces. Home buyers, Realtors, lending institutions and other organizations interested in the potential risk of damage to a specific structure also can benefit from increased reliability and certainty provided by the present invention. The precise substance and format of report 40 can be tailored to fit specific needs of any particular market segment or audience.
Although the present invention has been described in terms of a preferred embodiment, it will be apparent to those skilled in the art that many alterations and modifications may be made to such embodiments without departing from the teachings of the present invention. Accordingly, it is intended that the all such alterations and modifications be included within the scope and spirit of the invention as defined by the appended claims. | Residential wood home structures are evaluated and classified according to a defined risk level relative to damage likely to be caused by earthquake shaking or wind forces. Susceptibility to damage is evaluated and predicted by a probabilistic software engine based on existing databases of geologic and/or wind data coupled with specific structural characteristics information obtained by an onsite inspection of the structure. The software engine combines these data sets, and produces a report with a reliable, quantified risk rating that can be used by insurance companies to make decisions regarding offering of insurance and rates of insurance. The report is also used by homeowners as an evaluation factor in deciding to strengthen the structure against earthquake and/or wind storm damage. Because of its high volume capability and affordability, this inventive process makes assessment of a home's risk relative to damage induced by earthquake shaking and/or wind forces available to a larger segment of the general market, including home owning and home buying persons. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to photographic materials processing apparatus and more particularly to a light tight processing tank apparatus for the processing or treating of photographic material such as the developing, fixing and washing of photographic film and paper, either black and white or color.
2. Description of the Prior Art
Equipment such as tank processors for photographic film and print material, in roll and sheet form, are well known in the art. Due to the necessity of assuring complete and rapid removal and changing of processing chemical solution to eliminate uneven development and contamination of one processing solution by another solution, processing tanks have been provided with means for filling through the top and draining through the bottom to avoid the necessity of having to invert the tank to drain processing solution. However, such prior art processing devices provided with bottom drain means are rather complex in construction and are often difficult or awkward to operate. In addition, the structure of such prior art processing tanks generally does not take into consideration the desirability and/or necessity for the recovery of processing solutions to minimize the expense incident to the processing of photographic films and papers. Some prior art processing tanks provided with a bottom drain valve do include a manual drain valve operator but the complexity and/or operation thereof is not suited to the rapid efficient draining of the processing solution and more significantly is not constructed so as to readily facilitate the recovery of processing solutions for reuse or servicing of the valve to remove potentially contaminating deposits of precipitated processing chemicals or solubilized light sensitive emulsion constituents. In this regard U.S. Pat. Nos. 1,208,244; 2,530,734; 2,748,678 and 3,677,163 are exemplary of prior art processing tanks of the above described general structure. Another shortcoming of prior art developing tanks is that they are generally not of variable capacity or of variable vertical extent and therefore are not suitable for providing a tank of exactly the proper size for the intended job so as to efficiently utilize processing solutions and minimize entrainment of air during agitation to minimize spotting from air bubbles that keep the processing solutions from uniformly acting upon the photographic emulsion.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a photographic film and print processing tank that provides for the efficient, economical, reliable, uniform processing of photographic film and paper.
Another object of the invention is to provide a processing tank that provides for the rapid uniform drainage of processing solutions while facilitating the recovery of the solutions in a simple efficient manner.
Another object of the invention is to provide a bottom draining processing tank having a readily serviceable bottom drain valve that preferaby coacts with a tank support to facilitate operation of the drain valve.
Another object of the invention is to provide a bottom draining processing tank that is constructed so as to enable the selective adjustment of the volumetric capacity and vertical extent of the tank to adjust the tank for each processing situation.
Other objects and advantages of the invention will be apparent to those skilled in the art by the description which follows when read in conjunction with the drawings.
The objects of the invention are attained by a processing tank in which a tank is provided with a generally conventional light tight closure and a novel bottom drain valve means whereby processing solution can be rapidly and completely drained from the tank and selectively recovered for reuse. A bottom drain valve operating means is provided to facilitate operation of the drain valve in a manner that insures complete recovery of processing solutions, which are preferably filtered during recovery. The body of the tank is provided with means for selectively varying the extent of the tank intermediate the top and the bottom drain valve carrying portion of the tank. The bottom portion is preferably provided with means to enable the tank to stand upright on a planar supporting surface. The valve operating means of the present invention preferably includes a processing tank supporting means that coacts with the valve operator to enable operation of the drain valve by relative movement of the processing tank and tank supporting means. In a preferred form of the invention the tank supporting means comprises a stand that supports the tank above a support surface a distance sufficient to enable placement of a beaker, or the like, under the bottom drain valve to collect the processing solution being drained from the tank. In order to facilitate cleaning the device, or replacement of a worn drain valve body or valve seat or valve member, the drain valve is preferably removably secured to the bottom of the processing tank. Further, within the bounds of not impeding the proper drainage of processing solutions the drain valve is preferably provided with a filter element whereby recovered processing solution may be directly returned to storage without the necessity of further handling.
DESCRIPTION OF THE DRAWINGS
Reference is now made to the accompanying drawings wherein like reference numerals designate like parts and wherein:
FIG. 1 is a perspective view of a photographic processing device embodying the invention;
FIG. 2 is an enlarged vertical sectional view of the device of FIG. 1;
FIG. 3 is a horizontal sectional view taken along the line 3--3 of FIG. 2;
FIG. 4 is a fragmentary vertical sectional view similar to the view of FIG. 2, illustrating relative movement of certain drain valve elements;
FIG. 5 is an exploded fragmentary perspective view of the embodiment of FIG. 1 showing certain details of the drain valve and drain valve operating means;
FIG. 6 is a top plan view of the drain valve operator of the device of FIG. 1;
FIG. 7 is a perspective view of a tubular member for selectively varying the capacity of the device of FIG. 1; and
FIG. 8 is a perspective view of another embodiment of a photographic processing device embodying the invention and provided with the tubular member of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The device, about to be described in detail, is disclosed for use in connection with the processing of photographic film and paper. Since the device of the invention can be utilized with conventional photographic film and paper holders, such as in the form of a reel or rack, it is not considered necessary to describe the structure of such a holder that would be utilized within the device to support the sheet material being processed.
With particular reference to FIG. 1 a processing tank indicated generally at 10 includes a tubular body portion indicated at 12 and a removable top closure indicated at 14 which includes a filling opening 16 provided with a closure cap 18 and a light baffle 20. The top closure structure described above is of generally conventional construction. The tank body 12 and top closure 14 are provided with means 22, such as complementary continuous or interrupted threads for example, for coupling the tank body 12 and top closure 14 in fluid-tight relation. It will be appreciated that the specific structure of the fluid-tight coupling means is merely a matter of choice and can be of any configuration that will removably couple the members in removable fluid-tight relation.
The tank 10 includes an integral bottom wall 24 provided with a bottom drain valve means 26 for rapidly and efficiently draining processing solution from the tank 10. In the preferred embodiment illustrated, the bottom wall 24 is frusto-conical and provided with a centrally disposed outlet port 25. The drain valve means 26 is coaxial with the port 25 to insure complete draining of processing solution. A light baffle 28, either integral or removable, the latter of which is shown, is provided to preclude entry of light into the tank through valve means 26. It will be appreciated that the bottom wall may be other than frusto-conical, and the drain valve other than centrally disposed so long as processing solution will drain completely and the valve means 26 is capable of being operated by means to be described. Turning now to FIGS. 2 and 4 it will be seen that the drain valve means 26 includes a valve body 30 threadably received in a threaded boss 32 integral with the tank bottom wall 24. The valve 26 is preferably a ball valve and includes an annular valve seat 34 provided with a frusto-conical valve port 36, that coacts with a spherical or ball valve member 37. The ball 37 is positioned and operated by a valve operator member 38 threadably journaled on the valve body 30. As seen best from a consideration of FIGS. 2, 4 and 6 the valve operator 38 includes an integral spider having a plurality of arms 40 and a centrally disposed ball supporting and positioning seat 42. As seen from a comparison of FIGS. 2 and 4 axial movement of the valve operator 38 relative to the valve body 30, by virtue of rotation of the threaded coupling of the operator 38 and body 30, seats and unseats the ball 37 with respect to the valve port 36. The valve operator 38 is preferably provided with a filter element 44 downstream of the spider. It will be appreciated that the dimensions of the tank outlet port 25 and the valve port 36 are selected so as to provide rapid and complete draining of processing solution from the tank 10. The lower portion of the tank body 12 is provided with means, indicated at 48, for supporting the tank 10 on a generally planar surface. To this end an exemplary means comprises an annular skirt 50 integral with the tank body 12, which skirt 50 extends downwardly a distance at least as great as the downward extent of the valve means 26 from the bottom wall 24. The valve 26 can be operated by reaching beneath the skirt 50 and rotating the valve operator 38 to open and close the valve as shown in FIGS. 4 and 2 respectively. However, a significant aspect of the invention resides in the fact that the skirt 50 also provides a means for positioning the tank 10 on a stand 52 that comprises a means for supporting tank 10 a substantial distance above a support surface by means of a plurality of legs 53 while also providing a portion of a means for operating the drain valve 26 as a result of relative movement of the tank body 12 and stand 52. The stand is generally dimensioned so as to permit placement of a receptacle, such as a beaker, under the stand to receive solution being drained from the tank.
The coaction between the drain valve 26 and stand 52, in the embodiment illustrated, is effected by provision on the exterior of the valve operator 38 of means for frictional or positive engagement with a valve operator operating means carried by the stand 52. In this regard, as best seen from FIG. 5 and 6, the outer periphery of the valve operator 38 is octagonal. The stand 52 includes a top 54 configured so as to telescope within the bottom of the tank body 12 for free rotational movement with respect thereto. The top 54 of the stand is provided with an aperture 56 and a tubular extension 58 complementary to the shape of the valve operator 38 to permit upward and downward movement of the valve operator 38 relative to the stand top 54 as the operator moves along the threads of the valve body. It will be appreciated that the structural details of the drain valve means and the stand can be varied considerably from that shown without departing from the concept of operation to the valve means by relative movement between the tank body and stand. In FIG. 1 it will be seen that the tank is provided with a legend to indicate that clockwise rotation of the tank 10 relative to the stand 52 effects rotation of the valve operator 38 to close the valve, as seen in FIG. 2, and counterclockwise rotation of the tank 10 effects opening of the valve, as seen in FIG. 4.
Turning now to FIGS. 7 and 8, it will be seen that another significant aspect of the present invention resides in the provision of means for varying the volumetric capacity and vertical extent of the tank body. Toward these ends the invention contemplates the provision of one or more tubular tank body extension members, or sleeves 60, which are complementary in cross-sectional configuration to the tank body 12. The sleeves 60 are provided with coupling means 122 complementary to the coupling means 22 of the tank body 12. Thus, as seen in FIG. 8, a sleeve 60 has been coupled in fluid tight relation to the tank body 12 and the closure 14 coupled in fluid-tight relation thereto so as to increase the volumetric capacity and vertical extent of the tank body. The tank can thus be varied to accommodate a plurality of stacked film or paper carrying drums or racks, or can be varied to enable the processing of a relatively large sheet of photographic film or paper supported on a suitable drum or arcuate rack.
Although not specifically set forth heretofore it will be appreciated that the device of the present invention may be fabricated of any material that is sufficiently rigid and is suitably inert to the processing solutions normally utilized. The tank and stand normally are of molded synthetic resin. While the drain valve means 26 is illustrated as being removable, so as to facilitate cleaning of the valve and permit replacement in the event the valve is worn or damaged, it will be understood that the valve body may be formed integral with the tank body.
From the foregoing it will be appreciated that the present invention provides a very versatile photographic processing tank that is highly suited to the economical and efficient processing of film and sheet material. While the invention has been described in detail with reference to preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention. | A photographic film and print processing tank having a bottom drain valve which in a preferred embodiment coacts with a tank support stand whereby the valve and stand cooperate to facilitate rapid substantial draining of processing solution and recovery thereof for reuse. The size of the tank is selectively variable to enable the volumetric capacity, and vertical extent, of the tank to be adjusted to minimize the amount of processing solution required for processing varying amounts and sizes of photographic film or print material. | 6 |
BACKGROUND OF THE INVENTION
The invention relates to a lift system that produces a vertical parallel movement of a platform relative to a base, and it also relates to a weighing system that has a sample changer equipped with the inventive lift system that produces the vertical parallel movement of a sample changer platform.
Lift systems are used in different technical fields where a vertical movement, e.g. of a platform or an object relative to a base is required.
For example in the field of weighing technology, a lift system in conjunction with a sample changer serves to transfer one or more weighing object units or weighing containers to a balance pan. In a frequently used arrangement, the balance pan is located above or below a sample changer position of a sample changer, where the balance pan and the sample changer are vertically movable in relation to each other.
A piece-counting apparatus with a balance is disclosed in U.S. Pat. No. 5,883,336. A rotating sample changer has receiver openings for a container into which the pieces are placed that are to be counted. An empty container is brought by the sample changer into the filling position above the balance. By means of a pneumatic lifting mechanism, a weighing platform is moved vertically to lift the container off the sample changer—by reaching through the receiver opening of the sample changer—in order to perform the weighing. The lifting mechanism in this apparatus has a pneumatic lifting cylinder arranged centrally below the weighing platform and, in addition, requires three guiding elements arranged around the lifting cylinder, each of which consists primarily of a pin guided in a sleeve.
Known technical solutions are in practical use for balances, in particular for comparator balances, where a sample changer working together with the balance is equipped with a single lift unit arranged in the middle of a platform that is vertically movable in relation to the weighing pan. This device is suitable for balances that are specified for smaller loads, e.g., in a range from a few grams up to a few kilograms because, due to the small overall dimensions of the sample changer and the balance pan, the vertical travel distance between the sample changer and the balance pan for the transfer of the weighing object is likewise relatively small. It is therefore possible to use a simple mechanical device, such as for example an eccentric, as a lifter unit, although the drive torque as well as the speed of the vertical movement are not constant over the vertical lifting range of an eccentric.
For balances with a fine resolution of the weighing result, it is of critical importance that after the transfer of one or more weighing object units onto the weighing pan, the combined center of gravity of the weighing object units should lie on a vertical line passing through the area where the load is introduced into the weighing cell. It is therefore a requirement that the vertical movement, e.g. for seating the weighing object on the sample changer, occurs in exact parallel alignment relative to the weighing pan and furthermore in a sufficiently gentle and jolt-free manner so that the weighing object units will not shift their positions relative to each other during the transfer.
As a principal observation, in the case of low-capacity balances that have a sample changer equipped with a centrally arranged lift unit, the small amounts of torque occurring in the transverse direction are not significant enough to present a problem. Nevertheless, if a balance of the same type is designed for larger loads, a single lift unit arranged in the middle of a platform that is vertically movable relative to the weighing pan can prove to be a problem. When the relatively heavy platform is raised and lowered, transverse forces can occur that have an adverse effect on maintaining exact parallelism in the movement of the platform. Constraining the movement in conformance with the existing state of the art by means of several guiding elements arranged around a central lift unit requires a large amount of space and allows little flexibility. Furthermore, in the case of pneumatic as well as hydraulic lifting systems, preventive measures have to be taken against an accidental lowering of the platform from the lifted position, e.g., if there is a malfunction.
OBJECT OF THE INVENTION
It is therefore the object of the present invention to provide a lift system that is capable of sustaining the transverse torques, in particular for a relatively heavy platform, e.g., for a sample changer in a high-capacity weighing system, and that is also capable of vertically moving the platform in a jolt-free manner and maintaining parallelism. At the same time, the objective also calls for a space-saving and flexible arrangement of the lift system.
SUMMARY OF THE INVENTION
In accordance with the present invention, a lift system for the vertical parallel movement of a platform relative to a base is equipped with at least three mutually interchangeable mechanical lift units of the same kind carrying the platform. The lift units are arranged in an at least triangular flexible layout on the base. The lift system has a drive system with a transmission device and a drive unit, wherein the transmission device connects the lift units to each other and to the drive unit. As a result, the lift units move up and down simultaneously and, consequently, the platform is always aligned in a plane that is substantially orthogonal to the direction of the gravity force.
With a lift system that has a plurality of lift units acting on the platform on more than one point or one line, it is possible to prevent the occurrence of transverse forces. The parallelism of the platform movement relative to a base that carries the lift units is assured, because there is a common drive system for all of the lift units and because the lift units are of the same kind and are mutually interchangeable. It is particularly advantageous if the lift units are to a large extent identical.
The arrangement of the lift units on the base is flexible, the only condition being that they form at least a triangle. This allows spaces to be freed up below the platform where other assembly groups can be accommodated and arranged; for example, a space can be freed up in a weighing system to accommodate the weighing unit that includes the weighing cell. This leads to a compact configuration of the overall system.
In contrast to a lift system consisting of several mechanical lift units where each of the lift units has its own drive unit, the lift system according to the invention has the advantage that it does not require any measures for the synchronization of the lift units. The inventive lift system is designed to produce a simultaneous vertical movement of all lift units. The lift units to be used in the inventive lift system are preferably of a kind in which the driving force or driving torque as well as the speed of the vertical movement are substantially uniform over the entire vertical lifting range.
In an advantageous embodiment of the invention, the lift system is driven by an endless drive belt, in particular a spur belt, where each lift unit is equipped with a gear pulley and the spur belt is in form-fitting engagement with the gear pulley. The drive unit is preferably an electric motor.
In a particularly advantageous embodiment, each lift unit is configured as a lifting cylinder with a cylinder tube and a cylinder rod, where the cylinder rod is connected to the movable platform and is movable axially by means of a spindle that is guided in a threaded nut. This provides the lift system with an inherent intrinsic safety with regard to a malfunction. If the drive unit fails or the spur belt breaks, the lift units and the platform resting on them will be kept in their current position and will not drop. The spindles of all of the lift units have external threads of substantially the same pitch.
In view of the variance due to manufacturing tolerances in the production of mechanical components, it is a particularly significant feature of the invention that each lift unit is individually adjustable and that the individual adjustability of each lift unit remains available even after the lift unit has been installed in the lift system.
The lift system according to the invention is particularly well suited for use in a weighing system, especially if the weighing system is equipped with a sample changer. Thus, according to the invention, a weighing system that has a weighing unit with a weighing pan and a sample changer for transferring the weighing object from the sample changer to the weighing pan has a lift system equipped with at least three mechanical lift units that are of the same kind, mutually interchangeable, carrying a sample changer platform, and occupying an at least triangular flexible layout on a base. The lift system further includes a drive system with a transmission device and a drive unit, wherein the drive system effects a simultaneous vertical movement of the lift units. At all positions of vertical displacement, the sample changer platform is always aligned in a plane that is substantially orthogonal to the direction of gravity.
Since this kind of weighing system is preferably equipped with a weighing cell that works according to the principle of electromagnetic force compensation, the lift system is made substantially of non-magnetic materials.
In a preferred embodiment of the inventive weighing system, the sample changer has a tray that is rotatable on the platform and that is configured to be raised and lowered together with the platform.
The weighing system is modular, which means that the weighing unit can easily be removed from the sample changer for servicing. The weighing unit in this arrangement has an understructure that allows the weighing unit to be set either on rollers so that it can be pulled out from an opening in the sample changer or to be set on feet when the weighing unit is installed inside the sample changer.
A lift system according to the invention can be employed particularly in situations where a lifting mechanism for large and heavy objects is needed and where at the same time a high degree of precision is required in the control of the lifting movement. The flexibility of the inventive lift system is also of advantage where platforms have to be lifted that are for example asymmetric, because the lift units can be arranged to support the platform at the places where they are required.
BRIEF DESCRIPTION OF THE DRAWINGS
Details of the invention are described below based on an example from the field of weighing technology embodied in a comparator balance with a sample changer which is illustrated in drawings using a largely schematic drawing format, wherein:
FIG. 1 shows an overall view of the weighing system in a perspective representation, wherein the weighing system has been taken apart to show the individual assembly groups;
FIG. 2 shows the lift system in a three-dimensional view;
FIG. 3 shows the drive system in a three-dimensional view;
FIG. 4 shows a lift unit in a three-dimensional view; and
FIG. 5 shows a lengthwise section through a lift unit.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates the weighing system which consists substantially of a sample changer 1 and a weighing unit 2 , shown taken apart in a three-dimensional view. Facing the viewer is the weighing unit 2 , which is accommodated in a separate housing. To the right and more towards the background of FIG. 1 is the sample changer 1 . The latter has an opening 4 for the weighing unit 2 . To move the weighing unit into position, the weighing unit 2 has an understructure 5 which allows the weighing unit to be selectively set either on rollers 6 , e.g., to move the weighing unit out of the opening 4 for servicing, or on feet 7 . When the weighing unit 2 is installed in its operating position within the opening 4 , it is set on three feet 7 (only one being visible in the drawing) by raising the rollers. By means of the fastener elements 3 , the weighing unit 2 is attached to the sample changer 1 , so that it can no longer change its position. The weighing unit 2 is enclosed at the front by a cover panel 8 . A force-transmitting rod member 10 that connects to the weighing cell (not shown) protrudes from the top of the weighing unit 2 , set back in a recess 9 for protection from air drafts.
The sample changer 1 stands on three cylindrical pillars 11 , each of which is height-adjustable at its bottom end for the purpose of leveling the sample changer. A circular tray 12 that is rotatable about its center point has sample receivers 13 arranged in four positions spaced at angles of 90° from each other. The sample receiver 13 is configured as a grate, so that a weighing pan 14 with protruding ridges can reach through the grate to pick up one or more weighing object units from the sample receiver 13 that is currently in the position above the weighing pan 14 . In FIG. 1 , the sample receiver 13 and the weighing pan 14 in the forward-facing sample changer position are shown taken apart. The ring 15 serves for additional protection of the weighing pan 14 from the influence of air drafts. Two drive units 16 , 17 , on the one hand for a rotary movement (drive unit 17 ) of the tray 12 , and on the other hand for an up and down movement (drive unit 16 ) are connected to the sample changer 1 .
FIG. 2 shows the lift system 21 of a sample changer 1 in a three-dimensional representation, viewed at a slight downward angle. The pillars 11 on which the sample changer 1 is supported have a horizontal step at about three fourths of their total height, where the profile shape of a hollow cylinder changes into a post 22 with the profile of a circular arc with the same radius as the pillar 11 . The step in the pillar profile supports a base plate 23 that serves as mounting base for the lift system 21 .
Four lift units 24 (three of which are visible in FIG. 2 ) are bolted onto the base plate 23 . The transmission device 25 , which connects the lift units 24 to each other and to the drive unit 16 , is likewise accommodated on the base plate 23 . The platform 26 , extending parallel to the base plate 23 , is supported by the four lift units 24 which can raise and lower the platform 26 in relation to the base plate 23 . Besides the lift units 24 , there is no other connection between the platform 26 and the base plate 23 .
The platform 26 has a circular passage opening 27 for the weighing pan 14 (see FIG. 1 ). The platform 26 is of a circular shape and has a step 28 along its circumference that serves to guide the rotary movement of the tray 12 (see FIG. 1 ). The tray 12 is supported by rollers that run along the step 28 as the tray turns in a circle. Furthermore, FIG. 2 also shows the opening 4 for the weighing unit 2 .
FIG. 3 represents a three-dimensional illustration of the base plate 23 with the platform 26 taken off, viewed at a slightly downward-directed angle. As shown in this drawing, the transmission device 25 for the lift system 21 is mounted on the base plate 23 . In the interest of clarity, the rotation mechanism, which is likewise mounted on the base plate 23 and is driven by the drive unit 17 , has been omitted in the drawing. The drive unit 16 , preferably an electric motor, serves to drive the lift system 21 . The four lift units 24 are connected to each other and to the drive unit 16 by an endless spur belt 18 . The spur belt 18 is trained over six guide pulleys 20 that are installed on the base plate 23 by means of pulley mounts 19 , so that the spur belt 18 runs without crossings in a closed loop parallel to the surface of the base plate 23 , connecting the drive unit 16 and all four lift units 24 . This assures that all lift units 24 are driven simultaneously. The concept of driving the lift units simultaneously and the substantially identical design of the lift units 24 among each other are prerequisites for maintaining parallelism in the raising and lowering of the platform 26 (not shown in FIG. 3 ) in relation to the base plate 23 by means of the lift units 24 .
The pulley mounts 19 for the guide pulleys 20 are bolted onto the base plate 23 . By slightly loosening the screw 50 of any of the pulley mounts 19 , the respective pulley mount with its pulley 20 can be swiveled slightly about the axis of the bolt, whereby the spur belt is loosened or tightened. The drive unit 16 , preferably an electric motor, can reverse its sense of rotation for the up and down movement of the lift units 24 .
The base plate 23 and the platform 26 are aligned in a plane that extends orthogonal to the direction of the gravity force, so that a precise transfer of one or more weighing object units can be performed from the sample receiver 13 to the weighing pan 14 (see FIG. 1 ).
FIG. 4 shows a lift unit 24 in a perspective representation. It has a mounting socket 29 standing on four stilts 30 , each of which has a screw hole 31 to hold a screw for fastening the mounting socket 29 to the base plate 23 . Between the stilts below the mounting socket 29 , there is a gear pulley 32 designed for a form-fitting engagement with the spur belt 18 . The gear pulley 32 has a groove 33 around its circumference to receive a precisely fitting ridge of the spur belt 18 .
Connected to the top of the mounting socket 29 , the cylinder tube 34 extends vertically upward. A cylinder rod 35 , shown protruding from the cylinder tube in FIG. 4 , is guided inside the cylinder tube and constitutes the vertically movable part of the lift unit 24 . The cylinder rod 35 has a narrower section at its upper end forming a horizontal ledge 36 . The ledge 36 supports the platform 26 (not shown here), which can be clamped between the ledge 36 and a clamping disk 37 that can be screwed tightly onto the lift unit 24 . All four lift units 24 are held in this manner between the base plate 23 and the platform 26 . It is important for the lift units 24 to be in exact vertical alignment on the base plate 23 , so that the platform 26 can be aligned parallel to the base plate 23 and orthogonal to the direction of the gravity force.
FIG. 5 shows a lengthwise section through a lift unit 24 . The drawing also illustrates at the same time how a lift unit 24 is installed as the connecting element between the base plate 23 and the platform 26 . Each lift unit 24 has at its lower end an axial bearing 38 in which a spindle 39 is rotatably supported. The axial bearing 38 , which serves to take up axial forces, is accommodated in an appropriately configured recess 52 of the base plate 23 . The recess 52 has a further set-back portion 53 at the center, so that the rotating spindle 39 has no contact with the base plate 23 .
The gear pulley 32 , which is surrounded as well as covered at the top by the mounting socket 23 , is fixed on the spindle 39 by two set screws (not shown in drawing) for which the tapped holes 40 are provided. The gear pulley 32 has a groove 33 around its circumference to receive the spur belt 18 in a form-locking engagement. The cylinder tube 34 is inserted in the mounting socket 29 from above and is seated on the top surface of the mounting socket 29 by means of a step 41 . The cylinder tube 34 forms the housing for the lift unit 24 and also serves as a guide for the cylinder rod 35 that moves inside the cylinder tube 34 . The bottom end of the cylinder tube 34 holds a radial bearing 42 that absorbs the radially directed forces exerted on the spindle 39 by the spur belt. The section 43 of the spindle 39 that extends above the radial bearing 42 has an external thread. As a counterpart to the external thread, a threaded nut 44 is fixedly installed in the cylinder rod 35 which runs coaxially inside the cylinder tube 34 , where the threaded nut 44 is interposed between the cylinder rod 35 and the spindle 39 . The external thread of the spindle 39 runs in the internal thread of the threaded nut 44 whereby the nut, and thus the cylinder rod 35 , is moved up and down relative to the cylinder tube 34 . An upper polymer bearing 46 and a lower polymer bearing 47 are interposed between the cylinder rod 35 and the cylinder tube 34 to guide the movement of the cylinder rod 35 .
The cylinder rod 35 contains a hollow space 45 to receive the spindle 39 as the lift unit 24 moves downward. At the top, the cylinder rod 35 protrudes from the cylinder tube, and the upper end of the cylinder rod 35 has a stepped-down section 48 forming a horizontal ledge 36 . The stepped-down section 48 of the cylinder rod 35 is inserted in the platform 26 which rests on the ledge 36 , with a rubber shim 49 inserted for damping. The platform 26 is attached to the lift unit 24 by inserting a clamping disk 37 in the recess 54 of the platform 26 and fastening the clamping disk 37 to the cylinder rod 35 with a screw from the top. As a damping measure, it is recommended to also insert a rubber shim 51 between the platform 26 and the clamping disk 37 .
As the spur belt 18 connects all of the lift units 24 to each other and to the drive unit 16 , all four lift units 24 are moved together at the same time. With the lift units 24 being substantially identical, in any event at least of the same type and mutually interchangeable, the arrangement performs a synchronous vertical movement of the cylinder rods 35 of all four lift units 24 , whereby the platform 26 remains parallel to the base plate 23 . The movement is jolt-free, and the transfer of the weighing object units from the sample receiver 13 of the sample changer 1 to the weighing pan is gentle enough so that the weighing object units will not change their positions relative to each other.
Differences between the lift units 24 that are due to manufacturing tolerances, e.g., variations between the pitches of the spindles 39 and possibly other components of the lift system, can be compensated by a height adjustment. To allow this adjustment, the cylinder rod has a hexagonal hole 55 above the tapped hole 56 that serves to fasten the clamping disk 37 . By inserting a matching key into the hexagonal hole 55 and turning the cylinder rod up or down, the lift system can be level-adjusted even in the installed condition of a lift unit 24 and with the spur belt 18 pulled tight.
The mechanical lift units 24 that are driven by a spindle 39 running in a threaded nut 44 put a substantially constant torque load on the drive unit and produce a lift movement of substantially uniform speed over the entire vertical lifting range. Furthermore, the intrinsic safety is inherently assured for this type of lift drive. This means that in case of a power failure of the drive unit 17 or if the spur belt 18 breaks, the lift units 24 , and thus the platform 26 , are held at their current positions, and an abrupt fall of the platform is not possible. | A lift system for effecting a vertical parallel movement of a platform relative to a base, in particular for moving a sample changer platform of a sample changer in a weighing system, has at least three substantially identical and mutually interchangeable mechanical lift units supporting the platform. The lift units occupy an at least triangular flexible layout on the base. The lift system is equipped with a drive system that includes a transmission device and a drive element, wherein the transmission device connects the lift units among each other and to the drive element. The arrangement produces a simultaneous vertical movement of the lift units with the platform always staying aligned in a plane that is substantially orthogonal to the gravity force. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/892,843 filed Oct. 18, 2013, which application is incorporated herein by reference.
[0002] This invention was made with Government support under Department of Energy Solar America Contract No. DE-FG36-08GO18009. The government has certain rights in this invention.
BACKGROUND
[0003] There is worldwide interest in solar photovoltaic (PV) cells that efficiently convert the sun's energy into low cost electricity. A major cost of silicon-based PV solar cells is the extremely high purity silicon (Si) used in PV cells. A significant reduction in the cost of high purity silicon would reduce the price of PV cells and both expand their use and expand the applications in which PV cells are competitive with traditional sources of electricity. An important feature of the cost of high purity silicon is the raw material source and the inherent cost of the manufacturing processes that isolate and purify the silicon contained in the raw silicon-containing materials that are processed to yield the high purity silicon used in solar cells.
[0004] Most high purity silicon manufacturing processes use carbothermal reduction of quartz/carbon mixtures. The raw material components most often used are centimeter or greater sized quartz and carbon containing feedstocks that are reacted at temperatures upwards of 1900° C. (3450° F.) to yield silicon purities of 97 to 99%. Impurity levels of 1-3% are considered relatively high and the resulting silicon is only usable in low-value metallurgical industries. This type of low purity silicon is called “metallurgical grade” silicon or Si met because of these relatively high levels of impurities.
[0005] For PV cells (Si pv ) and electronics grade (Si eg ) silicon, the required purities are typically greater than 99.999% (termed “five nines” purity) and often greater than 99.999999% (“eight nines” purity) respectively. These high purity requirements require expensive further purification steps that typically require a chemical reaction of lower metallurgical grade Si met with hydrochloric acid (HCl) to produce HSiCl 3 and SiCl 4 . HSiCl 3 can be further reacted to produce SiCl 4 and SiH 4 . SiH 4 is further decomposed in a second high temperature step, typically to produce electronics grade silicon of nine nines purity (Si eg ). The SiCl 4 can also be reacted with H 2 to produce HCl and SiH 4 or six nines or high purity solar grade silicon or Si pv , but the processes require extremely high temperatures and other energy intensive steps that significantly increase the cost of the overall process.
[0006] The necessity of using HCl gas and chlorosilanes in multiple high temperature steps, coupled with the need to recapture HCl and prevent release of chlorosilanes into the atmosphere during processing, results in major capital expenditures. Furthermore, these are energy intensive processes that add massive expense to the cost of producing high purity Si-based PV cells. Although earlier work by some scientists suggested the potential to avoid chlorosilane processing, these efforts did not result in actual production of high purity silicon from rice hulls.
[0007] As noted above, an important cost factor is the raw material source of the silicon used in the manufacturing and purification processes that yield high purity silicon. While sources such as sand and quartz rock are commonly used, agricultural products are also known to contain high quantities of raw and purse silicon. For example, a number of agricultural grains and grasses are known to concentrate silicon in their stalks and seed hulls and are, therefore, an attractive source of silicon because the seed hulls and stalks are waste products that are created when other useful parts of the plant are processed to produce food products. Also, some agricultural waste products, such as rice hulls, are further processed i.e., burned to produce energy and the resulting inorganic byproduct, such as rice hull ash, contains many of the valuable original inorganic components such as silica. However, the byproduct also contains other impurities that require extensive chemical processing and purification steps to recover the desired silicon at high purities.
[0008] Very significant differences exist in the processing and purification processes between rice hull (RH) and rice hull ash (RHA). RHA impurities are more reactive with acids than those in RH. While this difference results in much higher purities following acid leaching, the difference in reactivities also requires different chemical processing steps to efficiently remove undesired impurities. In addition, while existing processes attempt to produce high purity silicon using rice hulls and/or group II metal reductants, there is no evidence that existing processes successfully produce high purity silicon having both the physical and chemical properties useful in applications that require extremely high purity silicon (5 nines and higher) and having only a minimal presence of certain key contaminants or impurities.
[0009] Accordingly, a need exists to develop a low cost, low energy process for 1) purifying RHA, (2) converting the purified RHA into polycrystalline silicon using carbothermal reduction, and 3) controlling the impurities during the process to meet or exceed the standards for high quality photovoltaic cells, such as solar silicon feedstock (SEMI III).
SUMMARY OF INVENTION
[0010] The current invention includes a method of producing high purity silicon using biogenic silica sources including grasses (wheat, rice, barley, oats, etc.) that take up SiO 2 in their stalks and seed hulls with minimal incorporation of the standard impurities found in “high purity quartz” as well as diatomaceous earth from diatoms. Thus the plants and diatoms naturally pre-purify the silica incorporated in their structure. Rice hulls (RH) have the highest silica content of all the grasses and are used as the example of a this patent in the form of rice hull ash (RHA). However, other forms of biogenic silica may be utilized in the same fundamental process.
[0011] The invention includes processing steps that reduce energy, reduce cost of materials, and reduce processing times using each of selected reagents, techniques and materials that individually improve the process from raw source material to final product. The process steps include selection of raw source material, milling of raw materials, specifically agricultural waste, and more specifically biogenic waste, such as rice hull ash (RHA), with acid to recover a purified intermediate silicon product. Several washing steps to are used further purify the silicon products and remove impurities. The further processing of acid-leached biogenic silica products with a catalytic base, and optionally a glycol, such as ethylene glycol or other diol to reduce silica content, is used to adjust the final SiO 2 :C ratio. Processing a purified biogenic silica product at high temperatures, typically in an electric arc furnace, combined with isolating molten silicon having purities of at least 99.99% purity, and also at least 99.999% and at least 99.9999% yields high purity silicon. Moreover, the resulting high purity silicon can be cast in molds allowing directional solidification/crystallization providing improved purities greater than 99.9999% (six nines purity).
[0012] This invention is the first demonstration that high purity silicon can be produced from biogenic silica, especially in the form of RHA, and specifically a high purity silicon having a purity greater than 99.99 wt. % purity and preferably closer to 99.9999 wt. % purity. Such high purity silicon is produced to specified purity values and absent threshold values for specific impurities. The resulting silicon products are conclusively and quantitatively demonstrated to meet the requirements of high purity and low contaminants. Still further, the processes described herein require less energy and are kinetically much faster than traditional electric arc furnace processing of Si met because of the intimate mixing (at 100 nm length scale) of SiO 2 and carbon in the RHA and other biogenically derived materials.
[0013] This invention is the first demonstration that high purity silicon can be produced from biogenic silica, especially in the form of RHA, and specifically that a high purity silicon can be produced from these raw materials resulting in a final purity greater than 99.99 wt. % purity, and greater than 99.9999 wt. % and preferably greater than 99.99999% and 99.999999 purity. Such high purity silicon is produced to yield specified silicon purity values and also absent threshold values for specific impurities that reduce the value of the resulting product. the resulting silicon products are conclusively and quantitatively demonstrated to meet the requirements of high purity and low contaminants needed for specialty photovoltaic and other applications. Still further, the process described herein require less energy and are kinetically much faster than traditional electric arc furnace processing of Si met because of the intimate mixing (at 100 nm length scale) of SiO 2 and the carbon in the RHA and other biogenically derived materials.
[0014] The invention also includes intermediate, partially purified silicon-containing compositions having characteristic components that result from the processes described herein and the selections of the raw material source and other parameters, including but not limited to C:SiO 2 ratios, densities, particle sizes, and absolute and combination profiles of impurities including but not limited to Aluminum, Boron, Calcium, Chromium, Copper, Iron, Magnesium, Manganese, Potassium, Sodium, and Phosphorus.
[0015] The invention may be also defined by final high purity silicon products having characteristic high purity levels for silicon and characteristic levels of impurities or combinations thereof including levels of impurities below threshold values usable in applications such as PV cells.
DESCRIPTION OF THE FIGURES
[0016] FIG. 1 is a schematic of a prior art silicon purification process using rice hulls (RH) as the source raw material, generally in accord with Amick et al. U.S. Pat. No. 4,214,920 (1980).
[0017] FIG. 2 is a schematic of a process to produce high purity silicon from rice hull ash (RHA) according to the present invention.
DETAILED DESCRIPTION OF INVENTION
[0018] Impurity levels for rice hulls harvested from around the world are known to be relatively similar. A number of prior art processes have been developed both to increase the purity of the silicon end-product and to remove impurities that impede performance of high purity silicon in PV and other electronic applications requiring high purity silicon. Prior art processes leach impurities by rinsing RHA with water five times followed by boiling in HCl:H 2 O at varying ratios and then washing with electronics grade water, per Table 1 columns 2-9 from left to right and Table 2. Thereafter, coking the rice hulls at 900° C. (with considerable evolution of gases and smoke) in flowing Ar/I % HCl (Table 1 column 10) forms a material with a C:SiO 2 ratio of 4:1 while keeping low impurity contents (Table 1 column 10) or even reducing impurities (relative to silicon content) by as much as 97 wt. % (Table 2c). In a fourth step, this material is further coked at ≈950° C. in flowing CO 2 to adjust the C:SiO 2 ratio to ≈2:1. In a fifth step, the feedstock in a particulate form is fed continuously into an electric arc furnace (EAF) heated to keep the walls at ≈1900° C. and thereafter the furnace is cooled allowing recovery of the purified Silicon. Note that the “Coked” HCl in column 10 in Table 1 is a 900° C. treatment with gaseous HCl, considerably increasing the cost of such processes in terms of the number of steps and the capital equipment needed to contain high temperature HCl.
[0019] In this prior art process, the coked RH is fed into the furnace in pellets formed using sucrose binders, leading to the results in Table 3a. Table 3b lists projected Si impurities, although absolute values for the projected impurities have not been quantitatively measured in these experiments.
[0000]
TABLE 1
Prior Art Amick et al characterization of RHs after specific treatments.
EMISSION SPECTROGRAPHIC ANALYSES OF RAW AND CLEANED RICE HULLS
Processing Steps
Previous
Previous
Clean
Clean
Rinses
Rinses
Plus 1:1
Plus 1 Hr.
1:3 HCl:H 2 O
1:1 HCl:H 2 O
Raw
5X
Plus
Plus 1:3
HCl:H 2 O
Soak in
Plus 1:1
Duplicate
Boiled 1 Hr.
Rice
Distilled
HCl
HCl:H 2 O
Boiled
Distilled
HCl:H 2 O
of Previous
Plus Coked
Hulls
Water
Aqueous
Boiled
20 Mins.
Water
Plus SC-2
Sample
in 1% HCl
(La.)
Rinses
Cleaning
1 Hour
20 Min. Hot
in Argon
Double
Acid
HCl/H 2 O 2
Raw
Water
Acid
Acid
Acid
Water
HCl/H 2 O
Cleaned
HCl
Impurities
Hulls
Washed
Cleaned
Cleaned
Cleaned
Soak
Cleaned
Duplicate
Coked
Dopants
B
10
40
—
10
10
10
10
10
5
Al
200
900
100
100
60
50
200
100
10
N.D.
Present
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Lifetime
Cr
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
10
40
N.D.
Killers
Mn
1500
1600
50
30
30
40
40
30
10
Fe
900
700
30
50
40
30
40
30
10
Cu
10
20
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Ni
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Mobile
Na
400
600
70
10
10
10
10
30
10
Ions
K
—
2000
—
30
10
10
20
20
10
Li
—
N.D.
—
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Mg
3000
2200
50
60
60
60
60
80
20
Ca
4000
6300
50
70
50
70
60
70
N.D.
Miscellaneous
Ti
20
200
10
60
60
60
70
200
N.D.
Zn
—
N.D.
—
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Pb
—
10
—
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Mo
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Pd
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Total
10,040
14,620
360
420
330
340
520
580
75
[0000]
TABLE 2
Prior Art Amick et al characterization of RH impurities after specific treatments.
a
T (h)
0.25
0.25
5.0
Ratio (HCl:H 2 O)
1:3
1:10
1:10
Temp. (° C.)
Boil
Boil
50
Impurity*
Concentration (ppmw)
Al
40
40
20
B
1
1
<1
Ca
30
20
150
Fe
4
4
15
K
5
5
200
Mg
15
5
90
Mn
5
3
50
Na
10
5
15
Ti
1
5
5
b
Average from preceding tables
Impurity*
Leached/
Coked
(ppmw)
Raw
Leached
coked
only
Al
10
10
50
50
B
2
1
0.7
10
Ca
1000
23
20
>1000
Fe
20
20
10
200
K
3800
30
90
>1000
Mg
500
10
40
1700
Mn
350
3
20
1000
Na
25
9
20
10
P
130
40
40
20
S
40
5
20
<1
Ti
3
9
2
10
Rice
Water
1:3 aqueous
1:1 aqueous
HCl
Impurities
hulls
washed
HCl cleaned
HCl cleaned
coked
Dopants
B
10
40
10
10
5
Al
200
900
100
60
10
P
N.D.
Present
N.D.
N.D.
N.D.
Lifetime killers
Cr
N.D.
N.D.
N.D.
N.D.
N.D.
Mn
1500
1600
30
30
10
Fe
900
700
50
40
10
Cu
10
20
N.D.
N.D.
N.D.
Ni
N.D.
N.D.
N.D.
N.D.
N.D.
Ti
20
200
60
80
N.D.
Zn
—
N.D.
N.D.
N.D.
N.D.
Mo
—
—
—
—
—
Mobile ions
Na
400
600
10
10
10
K
—
2000
50
10
10
Mg
3000
2200
80
60
20
Ca
4000
6300
70
50
N.D.
Miscellaneous
Pb
—
10
N.D.
N.D.
N.D.
Pd
—
—
—
—
—
Total (Other than Si)
10,040
14,820
420
330
75
Residue (Ash)
13.99%
13.58%
10.82%
55.74%
*Other impurities <1 ppmw.
[0000]
TABLE 3
Prior Art Characterization of impurities (a) Pellets produced with
sucrose binder and coked, (b) PROJECTED final Si impurity levels.
Sample
Sucrose
Relative
no.
(%)
Density
strength
8
12
816*
Low
4
13
816*
Low
CRP-3
15
1.44**
Medium
7
17
784*
Medium
CRP-2
21
1.35**
High
CRP-1
32
1.17**
High
Conc. in silicon (ppmw)
Impurity
Coked-only hulls
Leached/coked hulls
Al
40
40
B
7
0.5
Ca
>500
10
Fe
160
8
P
3
6
Ti
8
2
*Bulk (g/l),
**Actual (g/cm 3 ).
[0020] In the process described herein, the preferred biogenic silica source is rice hull ash (RHA) typically having a density of between about 1.5-2.0 g/cc, which is less voluminous than rice hulls (0.7-1.1 g/cc), thereby minimizing the capital equipment and transport expense for a given mass of material.
[0021] The following steps disclose the basic advantages of the process steps of the present invention. The steps are susceptible of standard revisions known to those skilled in the art based on known process and energy input considerations. The first step in the process of the invention extracts impurities with dilute HCl solution and washes with distilled water, but at lower acid concentrations compared to prior processes.
[0022] In this step, RHA is milled in acid to remove impurities. Rice hull ash is milled in dilute acid for 3-120 hours preferably from 12 to 72 hours and most preferably from 24 to 48 hours at a pH preferably less than about 5, and then washed with two equal volumes of water with vigorous agitation and then with an equal volume of boiling water after filtration to remove acid. Following additional, water washes, the milled RHA is then subjected to catalytic base/ethylene glycol or other diol described in U.S. Publication No. US2013/0184483 A1, Jul. 18, 2013 publication date, to reduce silica to carbon ratios. The step of working lower purity silicon products with water preferably is comprised of washing with at least 2 aliquots of water having incongruous temperatures and the intermediate product is molded wet. Table 4 reveals the utility of milling in lower acid concentrations and the importance of washing with water after each step using acid. A boiling water wash (BWW) is an added important step that provides much lower impurities without high temperature (900° C. HCl) treatments.
[0023] Acid milling removes most impurities efficiently, but one important aspect is that impurities dissolve in acid solution can re-absorb. Water washed after milling remove re-absorbed species, often in amounts comparable to those initially removed by milling. Also while RHA contains significant phosphorous as phosphates, the high solubility of phosphates in dilute acid reduces the presence below detectable levels early in the process. Also, while potassium is present as a mixture of potassium oxide, hydroxide and carbonate, all three compounds are very soluble in dilute acid and are effectively removed in the early processing steps.
[0024] By requiring much less concentrated acids, purification of RHA by the processes disclosed herein is much more cost effective than existing techniques. As measured per unit of contained silica purified, the RHA purification process described herein requires 5 time less acid. Accordingly, at equivalent size, the processing equipment can purify RHA at 5 times the rate of RH. Additionally, RH acid extraction leads to an undesirable wet product that must be dried prior to conversion to RHA, thereby consuming more energy and resulting in a significant loss of net energy.
[0000]
TABLE 4
Total
Ppm
Al
B
Ca
Cr
Cu
Fe
Li
Mg
Mn
Ni
K
Na
Ti
P
Zn
ppmw
RHA/raw
340
16
1200
<1.0
4.8
350
ND
750
260
ND
11400
260
0.2
2100
50
16732
after milling
140
5
190
<1.0
1.2
240
ND
210
60
ND
1300
35
ND
10
0.3
2193
after cold wash
64
4
76
<1.0
0.5
110
ND
40
22
ND
150
5
ND
ND
ND
473
after hot wash
64
4
45
<1.0
0.5
45
ND
32
20
ND
80
5
ND
ND
ND
297
After BWW
12
2
21
ND
ND
14
ND
8
8
ND
10
3
ND
ND
ND
78
Complete process
1
1
11
ND
ND
2
ND
5
2
ND
6
3
ND
ND
ND
31
[0025] Table 4. Various simple treatments of RHA to remove impurities. Raw; after milling in 3.7 wt. % HCl (1:10 HCl:H 2 O); after milling in 3.7 wt. % HCl then water washed; after milling in 3.7 wt. % HCl then hot water washed; after milling in 3.7 wt. % HCl then boiling water washed (BWW) under reflux overnight; after milling in 3.7 wt. % HCl, then displacement washed, then leached in boiling acid (6.2 wt %) under reflux overnight, then boiling water washed (BWW) under reflux overnight (Complete process). Data presented in ppmw, carbon not included.
[0026] In the next step, purified RHA is further processed by either of two paths. (See FIG. 2 ). In a first and simpler path, high purity carbon (preferably graphite powder) is added to the purified RHA to adjust the C:SiO 2 to ≈2:1. Addition of fine carbon powder preferably adjusts the C:SiO 2 ratios to less than 2.1:1 and including ranges of from 1.4:1 to 2.1:1, preferably 1.6:1 to 2.0:1 and most preferably 1.65:1 to 1.9:1, and this mixture is carbothermally reduced in an electric are furnace (EAF) or an induction furnace. In a second path, the C:SiO 2 ratio of the purified RHA is adjusted by extraction with ethylene glycol or some other diol and catalytic amounts of base as described in U.S. Pat. No. 8,475,758, which is specifically incorporated by reference herein.
[0027] This extraction method of U.S. Pat. No. 8,475,758 currently requires 6-20 hours to remove 20-50% of the silica to adjust the C:SiO 2 ratio to near 2:1. Removing significant amounts of SiO 2 generates higher porosity allowing further purification with follow-on acid reaction and BWW. Optimally the silica extraction follows acid milling and a simple water wash of the RHA. Thereafter, a further impurity extraction step with dilute acid, followed by hot and more preferably a BWW wash, eliminates the need for the 1% HCl/Ar step used in the prior art process described in FIG. 1 . The purities in the “complete process” of Table 4 are superior to those of Table 1, column 10.
[0028] The next step is EAF carbothermal reduction to produce Si pv as discussed below. It should be noted that purified RHA and purified silica depleted RHA (SDRHA) can be formed into pellets without the use of the binders, e.g. sucrose, that were the standard practice in the prior art.
[0029] Referring again to FIG. 2 , this process avoids the two high temperature steps shown in FIG. 1 , e.g. coking and carbon oxidation, and avoids the low temperature sucrose addition step. The process of the invention as shown in FIG. 2 adds either carbon powder or an extraction step for adjusting C:SiO 2 and an additional HCl wash that obviates a costly 900° C. 1% HCl/Ar step/coking step. The impurities in the silicon produced in this process can be further reduced by directional solidification and/or a conventional Czochralski recrystallization before the resulting product is used to make silicon boules. These two paths also avoid the Siemens process entirely, greatly reducing anticipated Si pv costs.
[0030] The fixed costs of the process described in FIG. 2 are significantly less than the prior art process of FIG. 1 . Specifically, the invention facilitates more efficient materials handling because the volume of the raw silica source (RHA vs. RH) is less. Shipping costs are lower and the capital costs for the chemical reactors and processing equipment is lower. While the process of FIG. 1 is energy intensive and costly, the production of RHA from RH used in the process generates energy equal or in excess of the energy required by the rest of the process.
[0031] In addition, RHA is available with a wide range of C:SiO 2 ratios, from 5:95 to 40:60 (Agrielectric of Lake Charles, La., USA produces pelletized RHA having a defined C:SiO 2 ratio 5:95 or at custom values selected by the purchaser); (Producers Mills RHA has a 40:60 ratio requiring less extraction to reach 2:1 ratios). The total silica content is higher than the desired amounts with respect to the carbon content present. If a catalytic base is used, then the resulting mixture is again filtered and the recovered material washed with dilute acid and then water or boiling water to eliminate residual base and the resulting material is then pelletized using components that are not plastic, plastic coated metal or ceramic or ceramic coated metal pellizing machines.
[0032] The average particle size of the molded pellet components are 0.5-2000 μm and are most preferably between about 0.05 to 10 μm. The pellets have densities of 0.7 g/cc to 2.0 g/cc, and most preferably between about 1.2 to 1.8 g/cc. The pellets have a diameter of 0.5 to 10.0 cm, and most preferably between about 2-5 cm.
[0033] Carbothermal (EAF) Reduction.
[0034] Carbothermal reduction of SiO 2 to Si in intimate mixtures with C commences at ≈1400° C.; however, SiC is the primary product if carbon is in large excess and only rapid heating in an arc or induction furnace can drive direct reduction to Si. The EAF temperature is preferably in the range of 1400° to 2100° C. and more preferably between about 1500° to 1900° C., and most preferably between about 1600° to 1850° C. The time of electric are furnace processing is for periods of 4 to 72 hours, more preferably times of 6-48 hours, and most preferably times of 10-40 hours. However, these are suggested times and are meant to be exemplary and not limiting. The data herein establish that the invention provides high purity Si and eliminates or reduces cross-contamination from extraneous EAF components which are a primary source of residual impurities.
[0035] Table 5. Comparison of KHUA impurity content and corresponding impurity level in the silicon produced for that Batch. All purities are metal based and by weight (ppm by weight, ppmw).
[0000]
TABLE 5
Batch
Si
Batch
Si
Batch
Si
Batch
Si
Si *
SEMI
ppmw
1
impurities
2
impurities
3
impurities *
4
impurities
impurities
III**
Al
180
0.7
350
3.5
1600
0
350
0
0.1
0.3
B
28
0.4
53
0.0
Unk
0.2
15
0.1
0.05
0.1
Ca
840
0.3
1400
10.9
5250
0.2
1400
0.2
0.3
0.1
Cr
<1.0
0.5
1.2
0
Unk
0.05
<1.0
0.05
0
0.2
Cu
4.6
0
8.3
0
Unk
0
4.6
0
0
0.2
Fe
190
12.7 †
330
5.6 †
1400
4.3 †
340
2.0 †
0.1
0.2
Mg
530
0.05
850
10.6
2400
0.03
740
0
0.01
0.1
Mn
160
1.0
240
7.5
1050
0.5
260
0.2
—
0.2
K
10000
0.5
20000
67.3
33800
0.4
11000
0.2
1.2
0.1
Na
250
0
410
2.7
650
0
260
0
0.4
0.1
P
2100
0
5000
0
1050
0
2000
0
0
0.05
% Purity
98
99.998
97
99.98
95
99.9994
98
99.9997
99.9997
99.999**
* Second run, batch 4
**SEMI standard also contains heavy metal impurities not discussed here (as RHA and Si made from RHA do not contain heavy metals).
† Cross contamination from metal holders for electrodes.
[0036] The process may be supplemented by automated addition of 2:1 C:SiO 2 pellets or other ratios that allow control of the Si production rates over periods of from 1-40 h such that continuous reduction is achieved such that molten silicon is produced and remains molten over the period of addition.
[0037] Table 6 provides data for process optimization from minimizing cross-contamination. For example, pyrex glass reactors are pre-rinsed with hot 3.75 wt % HCl prior to introduction of milled and BWW washed RHA to minimize contamination from the borosilicate glass surface. This reduces the Boron and Aluminum content impurity, but Aluminum impurities from the furnace bricks are still thought to cause residual cross contamination. The purities observed in Tables 5-6 are prior to any effort to recrystallize the resulting silicon, which is anticipated to produce up to 8 Ns purities depending on the method of recrystallization used.
[0038] The process of isolating molten silica is comprised of decanting or filtrating molten silicon from by-product SiC with casting into heated molds, cooling the molds along a gradient to induce a crystallization front from one end to the other end of the mold. This technique drives and concentrates the impurities in front of the crystallization front leading to one end of the cooled, molded silicon having higher concentrations of impurities than all of the remaining silicon such that this silicon end can be cut off for recycling.
[0039] Table 6. Impurities in last EAF produced silicon sample (all numbers based on metal purity so C is not taken into account).
[0000]
TABLE 6
Si impurities
Si impurities
Si impurities
Si impurities
ppmw
ppmw
ppmw
ppmw
SEMI III
ppm
Experiment #1
Experiment #2
Experiment #3
Experiment #4
Standard
Al
0
0.2
0.2
0.3
0.3
B
0
0
0
0
0.1
Ca
0.1
0.1
0.1
0.1
0.1
Cr
0
0
0
0
0.2
Cu
0
0
0
0
0.2
Fe
0.5
0.4
0.5
0.4
0.2
K
0.4
0.05
0.03
0.02
0.1
Mg
0.1
0.06
0.1
0.1
0.1
Mn
0.2
0.2
0.2
0.2
0.2
Na
0.2
0.04
0.03
0.02
0.1
P
0
0
0
0
0.05
Purity
99.9998%
99.99988%
99.99988%
99.99986%
99.999%
[0000]
TABLE 7
Table 7. Impurities detected in bulk silicon sample
Si impurities
Si impurities
Si impurities
ppm
ppm
ppm
ppm
Example 6
Example 7
Example 8
SEMI III
Al
34
0.5
0.1
0.3
B
2
ND
ND
0.1
Ca
0.3
0.2
0.1
0.1
Cr
ND
ND
ND
0.2
Cu
ND
ND
ND
0.2
Fe
5
0.4
0.2
0.2
K
0.5
1.0
0.05
0.1
Mg
2
0.1
0.05
0.1
Mn
4
0.3
ND
0.2
Na
0.5
0.9
0.02
0.1
P
ND
ND
ND
0.05
Purity
99.99%
99.999%
99.9999%
99.999%
[0040] As seen in Tables 5-7, the purities achieved are much higher than anticipated by the projected purities of the process of FIG. 1 and Table 3b. For example, the Aluminum and Calcium impurities are two orders of magnitude smaller than anticipated. Further, Boron, Phosphorus, and Titanium are not detectable. Still further, the iron quantities are more than an order of magnitude smaller than the process of FIG. 1 . Furthermore, no reported values exist for Sodium or Potassium contamination. However, electric are furnace (EAF) processing at time periods of 6 h gives Sodium or Potassium contamination at 0.5-2 ppm which are reduced to 0.02 ppm if the process times are greater than 6 h because these elements, along with other alkali and alkaline earth metals, evaporate during the longer process times.
[0041] The EAF used in the Examples below is a 50 kW single top electrode direct current furnace using graphite walls. The inside of the walls, in contact with the RHA, and the silicon, do not react with graphite and are observed to remain intact after each application of the process, and thus do not contribute carbon to the reaction. Example 6 below shows that higher power and/or temperatures produce higher batch yields, but sometimes at the expense of purity.
[0042] The arc power settings, once operating temperature is reached, are from 7 kW to 20 kW, corresponding to 8-12 kWh of energy consumed per kg of feedstock at present scale. Scaled up to a 10 kg/h silicon production theoretical capacity, this represents a 44% increase in Si production rate (5.8 kg/h vs 4 kg/h for conventional feedstock) and a 13% reduction in energy costs (33.6 kWh/kg of Si vs 40 kWh/kg of Si for conventional feedstock).
[0043] By using purified RHA as feedstock, the amorphous silica is intimately pre-mixed with some carbon (carbon initially present in RHA before graphite addition) at the submicron scale. The time to complete reaction is controlled solely by the distance species in the largest particles must travel (diffuse) to reach the reaction zone (typically at the particle surface). Hence the larger the biggest particles are, the longer time it takes to get complete reaction. The following empirical formula, Equation (1), can be used as a guide to predict reaction times for solid-state reactions.
[0000]
[
1
+
(
z
-
1
)
x
]
2
3
+
(
z
-
1
)
(
1
-
x
)
2
3
=
z
+
2
(
1
-
z
)
Kt
r
A
2
[0044] Equation 1 describes the time required for reactant A particles of radius r, and mole fraction x, to react given a global rate constant Kt for reaction, where z is the unit volume of product formed from a unit volume A. The latter accounts for changes in density. This formula is a relatively crude method of predicting solid-state reaction times because it does not consider phase changes, or impurities in primary particles, or aggregates. It does indicate that the production of Si0 g , should be faster when using RHA than by using the usual quartz and coal feedstock.
[0045] Si, O and C elemental mapping of the purified RHA was performed to confirm the nanometer scale mixing of the SiO 2 and C in RHA. As observed in FIG. 2 , carbon and silicon atoms are relatively homogeneously dispersed in the RHA particles confirming the intimate mixing of the amorphous SiO 2 and C in the RHA. FIG. 2 also shows that the apparent individual particle sizes are approximately 50-100 nm in size.
[0046] In addition this intimate mixing results in very much smaller diffusion distances: the time to complete the transformation to silicon should be much faster meaning high throughput in a continuous reactor and or the potential to use a smaller EAF and less electricity to produce identical amounts as the processing times are reduced.
[0047] In a small scale EAF, most of Sio g leaves the reaction zone. In the following examples, the high concentration of Si g in the reactor results in a quantity condensing back into the reaction zone, as occurs in larger reactors. This explains the higher than expected yields. The high rate of SiO g production probably also explains the high rate of conversion of the RHA to silicon. The rate of purified RHA consumption in the system is roughly 4× the rate expected compared to typical quartz/coal feedstocks. Even though currently the carbothermal reduction of silica to silicon only represents a small fraction of the price of final Si pv (Si met only costs $3/kg), a faster rate of conversion has some benefits. If these results are confirmed at industrial scales, energy losses as well as the amortizing cost of the capital equipment per kg of Si produced will be lowered.
[0048] All analyses were conducted using ICP-OES analysis of HF digested samples.
Example 1
Conversion of Purified RHA to Si Via EAF Carbothermal Reduction, Single Batch Process
[0049] 4.3 kg of purified RHA (similar to Table 4 after complete process) was mixed with 615 g of high purity graphite powder, then 2.3 L of distilled water was added and the slurry was formed into 40-50 g spherical pellets. Pellets were dried for 8 h at 225° C. then placed inside the EAF. Power was quickly increased from the initial 2 kW to 16 kW at 200 kw/min; it took 6 h for all the RHA to react. 220 g of silicon was collected, analysis shown in Table 5 column 2. EAF used in these experiments is the 50 kW single top electrode direct current EAF using graphite walls described above.
Example 2
Conversion of Purified SDRHA to Si Via EAF Carbothermal Reduction, Single Batch Process
[0050] Silica depleted RHA (SDRHA) was prepared by reacting milled RHA (milled in 3.7 wt. % HCl, then washed in water, then neutralized using 10 wt. % ammonium hydroxide solution) in ethylene glycol (36.2 L) and catalytic amount of sodium glycolate silicate (3.94 mole of SGS) where 40 wt. % of the silica was extracted. SDRHA was then filtered, washed in water, then acid leached in 6.7 wt % HCL, then washed in boiling water. Pellets were dried for 8 h at 250° C. 265 g of high purity graphite powder was added and 3.2 L of distilled water was added and the slurry was formed into 40-50 g spherical pellets. Pellets were dried for 8 h at 250° C. then placed inside the EAF. Power was quickly increased from the initial 2 kW to 16 kW at 200 kw/min; it took 6 h for all the RHA to react. 110 g of silicon was collected. The analysis is given in Table 8 below.
[0000]
TABLE 8
Analysis of Si produced from SDRHA. (all numbers based
on metal purity so C is not taken into account)
Impurities
Al
B
Ca
Cr
Cu
Fe
Mg
Mn
K
Na
P
Purity
Si impurities
0.4
ND
1.6
ND
ND
3.6
0.6
ND
1.7
1.2
ND
99.9990%
ppmw
Example 3
Conversion of Purified RHA to Si Via EAF Carbothermal Reduction, Multi Batch Batch Process
[0051] 9.5 kg of purified RHA (similar to Table 4 after complete process) was mixed with 1273 g of high purity graphite powder, then 7 L of distilled water was added and the slurry was formed into 40-50 g spherical pellets. Pellets were dried for 8 h at 225° C. ⅓ of the pellets were placed in the EAF. Power was quickly increased from the initial 5 kW to 11 kW in 30 minutes, after 4 hours power was reduced to 7 kW; another ⅓ of the pellets was added after 8 h, then the final third after 13 h. Total run time was 19 h. 350 g of silicon was collected, analysis shown in Table 6, column 2.
Example 4
[0052] In this example, the same methods were used as in Example 3. The approximate yield was 600 g and the analysis is that given in Table 6, column 3.
Example 5
[0053] In this example, the same methods were used as in Example 3. The approximate yield was 450 g and the analysis is that given in Table 6, column 4.
Example 6
[0054] In this example, first 20 kg of RHA was milled twice (3.7 wt % HCl), washed with water and boiling water (BBW). 15.2 kg of pellets were formed and one-third of the pellets were placed in the crucible and the arc was started at 4 kW and increased to 15 kW after 30 min. A uniform but somewhat higher than normal operating temperature was reached after 5 h and 12 kW was required to keep the temperature stable. Another third of the pellets was added after 10 h with the final third added after 16 h. The total run was 22 h and gave approximately 1.4 kg of silicon and approximately 0.2 kg of SiC.
[0055] The production quantities at higher temperatures were more than double those of previous examples. However, the higher temperatures also generated more impurities from the supporting structure of the EAF at this level of production as seen in Table 7 yielding Si purity to 4 Ns as a result.
Example 7
[0056] 11.3 kg (dry weight, 15.6 kg actual weight) of purified RHA pellets were prepared for this run. ⅓ of the pellets were placed in the crucible and the arc was started at 4 kW and increased to 12 kW in 30 minutes. Operating temperature was reached after 5 hours and 9.5 kW was required to keep temperature stable (top of the furnace was slightly different to try to limit Al contamination). Another third of the pellets was added after 10 hour, and the final third was added after 16 hours. Total run was 21 hours. Once the EAF cooled down, 550 g of silicon was collected. The purity is 6 Ns per Table 7.
Example 8
[0057] The run that gave the highest silicon purity (6 Ns) had a yield of 550 g (16% of theoretical yield): Initially 3.76 kg (dry weight) of purified and carbon adjusted RHA pellets (using Path 1) were placed in the crucible, after 10 h another 3.76 kg was added, then a final 3.76 kg after 16 h. Total arc duration was 21 h at which point the arc was shut and the system allowed to cool down before the silicon could be collected. The initial setting of the arc is 4 kW, increased to 12 kW in 30 minutes. The power was reduced after 5 h to 9.5 kW to keep temperature constant (1880-1930° C.). On cooling, 550 g of silicon was collected (16% of theoretical yield).
Example 9
[0058] The run that had the highest yield produced 1.4 kg of silicon from 10.9 kg of RHA (dry weight) of Path 1 pellets (C:SiO 2 ration 1:1.65). One-third of the pellets were placed in the crucible, then the arc was started at 4 kW and increased to 15 kW after 30 min. A uniform but somewhat higher than normal operating temperature (temperature could only be measured reliably at the bottom exterior of the crucible: 2015-2040° C. vs. 1850-1930° C. for standard operation) was reached after 5 h and 12 kW was required to keep the temperature stable. Another third of the pellets was added after 10 h with the final third added after 16 h. The total run time was 22 h and gave ≈1.4 kg of silicon (37% of theoretical yield). | A low cost process is provided for creating high purity silicon from agricultural waste, particularly rice hull ash. The process uses a series of chemical and thermal steps to yield high purity silica while using less energy and more efficient chemical processes. The high purity silicon features fewer impurities that negatively affect the use of high purity for PV cells and reduces capital and operating costs of processes to yield ultra-pure silicon. | 2 |
RESERVATION OF COPYRIGHT
[0001] A portion of the disclosure of this patent document contains materials that are subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND
[0002] 1. FIELD
[0003] The present invention relates generally to garbage collection and, more specifically, to root set enumeration in a garbage collection process.
[0004] 2. DESCRIPTION
[0005] The function of garbage collection, i.e., automatic reclamation of computer storage, is to find data objects that are no longer in use and make their space available for reuse by running programs. Garbage collection is important to avoid unnecessary complications and subtle interactions created by explicit storage allocation, to reduce the complexity of program debugging, and thus to promote fully modular programming and increase software application portability. Because of its importance, garbage collection is becoming an integral part of managed runtime environments.
[0006] The basic functioning of a garbage collector may comprise three phases. In the first phase, all direct references to objects from currently running programs for all threads may be identified. These references are called roots, or together a root set, and a process of identifying all of such references may be called root set enumeration. In the second phase, all objects reachable from the root set may be searched since these objects may be used in the future. An object that is reachable from any reference in the root set is considered a live object; otherwise it is considered a garbage object. An object reachable from a live object is also live. The process of finding all live objects reachable from the root set may be referred to as live object tracing (or marking and scanning). In the third phase, storage space of garbage objects may be reclaimed (garbage reclamation). This phase may be conducted either by a garbage collector or a running application (usually called a mutator). In practice, these three phases, especially the last two phases, may be functionally or temporally interleaved and a reclamation technique may be strongly dependent on a live object tracing technique. Depending where root set enumeration occurs, the root set enumeration may be called register root set enumeration (hereinafter register enumeration), heap root set enumeration (hereinafter heap enumeration), or stack root set enumeration (hereinafter stack enumeration). Compared to stack enumeration, overheads incurred by root set enumeration in other storage areas are usually small in a typical application and may be ignored.
[0007] When free storage space is running below a limit, garbage collection may be invoked and all threads may be suspended so that root set enumeration for each thread may be started (for concurrent garbage collection, some threads might not be suspended in order to invoke root set enumeration). For stack enumeration for a thread, the stack frame (in the thread's stack) where the thread is suspended becomes a current frame from which stack enumeration may start. All live references in the current frame may be identified and enumerated. After the current frame is enumerated, the next stack frame (i.e., a caller's frame) in a call stack becomes a current frame in which all live references may be identified. This process, which is referred to as stack unwinding, continues until all frames in a call chain are walked through and enumerated.
[0008] A stack unwinding mechanism involved in the stack enumeration in a garbage collector unwinds or walks up stack frames of a call stack, one frame at a time, to identify currently active references, i.e., references to form a root set. For some applications, especially those with a large number of threads and a deep call chain per thread, stack unwinding incurs significant runtime overhead for garbage collection. The more threads there are and the deeper the call chain is per thread, the higher the runtime overhead that may be used. Therefore, it is desirable to improve the efficiency of stack enumeration by reducing the overhead incurred by stack unwinding.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The features and advantages of the present invention will become apparent from the following detailed description of the present invention in which:
[0010] FIG. 1 depicts a high-level framework of an example managed runtime system that uses at least one stack trace cache to improve the performance of garbage collection, according to an embodiment of the present invention;
[0011] FIG. 2 is an exemplary flow diagram of a high-level process in which a stack trace cache is used during root set enumeration for garbage collection in a managed runtime system, according to an embodiment of the present invention;
[0012] FIG. 3 is a high-level functional block diagram of a stack enumeration mechanism that uses a stack trace cache, according to an embodiment of the present invention;
[0013] FIG. 4 is an exemplary flow diagram of a process in which a stack trace cache is created and used to improve the performance of root set enumeration during garbage collection for a thread, according to an embodiment of the present invention; and
[0014] FIGS. 5 ( a )-( d ) are schematic illustrations of the status of a stack trace cache during different sessions of stack enumeration for a thread, according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0015] An embodiment of the present invention is a method and apparatus for improving the performance of root set enumeration for garbage collection using at least one stack trace cache. The present invention may be used to reduce the overhead of stack enumeration during garbage collection in software applications with a large number of threads and a deep call chain per thread, without much cost. In many software applications, a function call chain in a thread may be repetitive, that is, caller and callee relationships might not change much, from one garbage collection session to the next. Such a characteristic may result in similar or partly similar stack traces for two consecutive garbage collection sessions. Thus, a stack trace cache may be used for the thread to store stack trace information, which reflects caller-callee relationships in a call chain. The stack trace information may comprise a list of stack frames, context information associated with each frame, current instruction pointer (IP), and/or source line number information. In the first stack enumeration (the first session of garbage collection), full stack unwinding may be performed and a stack trace cache may be created to store trace information for each frame in a stack. In the second or later stack enumeration (the second or later session of garbage collection), part or all work involved in full stack unwinding may be avoided by simply retrieving repetitive portions of stack trace information from the stack trace cache. Also in the second or later stack enumeration, the stack trace cache may be modified to accommodate new traces and/or to update old traces.
[0016] Reference in the specification to “one embodiment” or “an embodiment” of the present invention means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrase “in one embodiment” appearing in various places throughout the specification are not necessarily all referring to the same embodiment.
[0017] FIG. 1 depicts a high-level framework of an example managed runtime system that uses at least one stack trace cache to improve the performance of garbage collection, according to an embodiment of the present invention. The managed runtime system 100 may comprise a core virtual machine (VM) 110 , at least one Just-In-Time (JIT) compiler 120 , a root set enumeration mechanism 130 , at least one stack trace cache 140 , and a garbage collector 150 . The core VM 110 is an abstract computing machine implemented in software on top of a hardware platform and operating system. The use of a VM makes software programs independent from different hardware and operating systems. A VM may be called Java Virtual Machine (JVM) for Java programs, any may be referred to as other names such as, for example, Common Language Infrastructure (CLI) for C# programs. In order to use a VM, a program must first be compiled into an architecture-neutral distribution format, i.e., intermediate language such as, for example, bytecode for a Java code. The VM interprets the intermediate language and executes the code on a specific computing platform. However, the interpretation by the VM typically imposes an unacceptable performance penalty to the execution of a bytecode because of large runtime overhead processing. A JIT compiler has been designed to improve the VM's performance. The JIT compiler 120 compiles the intermediate language of a given method into a native code of the underlying machine before the method is first called. The native code of the method is stored in memory and any later calls to the method will be handled by this faster native code, instead of by the VM's interpretation.
[0018] The root set enumeration mechanism 130 may identify initial live references (roots) in a stack, registers, and other storage areas. The root set enumeration mechanism may be a part of the core VM 110 , a part of a garbage collector, a part of both the core VM and the garbage collector, or separate from either the core VM or the garbage collector. The root set enumeration mechanism may comprise a stack enumeration mechanism 135 to identify live references in a stack, a register enumeration component to identify live references in registers, and other components to identify live references in other storage areas. Since stack enumeration may incur more overhead than enumeration in registers and other areas, a stack trace cache 140 may be used to reduce stack enumeration overhead for a thread. A stack trace cache may comprise a storage space in memory. In one embodiment, the stack trace cache may be implemented using dynamic and scalable data structures such as, for example, a linked list.
[0019] The stack enumeration mechanism 135 may use a stack trace cache to store stack trace information for a thread. The stack trace information may comprise a list of stack frames, context information associated with each frame, current instruction pointer (IP), and/or source line number information. During the first stack enumeration (for the first garbage collection session), the stack enumeration mechanism may create a stack trace cache and cache the stack trace information in the stack trace cache, while the stack enumeration mechanism walks through and enumerates every frame in a stack, i.e., unwinds the entire stack. During the second or later stack enumeration (for the second or later garbage collection session), the stack enumeration mechanism may first start to walk through each frame in the stack. For a frame, the stack enumeration mechanism may detect if trace information starting from the frame is cached in the stack trace cache. If the trace information starting from the frame is cached, it may mean that the stack enumeration mechanism can directly use the trace information without further unwinding the stack. On the other hand, if the trace information starting from the frame is not cached, or has changed since the last stack enumeration, the stack enumeration mechanism may modify the stack trace cache to cache the new or updated trace information. After the second or later stack enumeration, the stack enumeration mechanism may update stack trace information in the stack trace cache.
[0020] The garbage collector 150 may comprise a live object tracing mechanism 152 and a garbage reclamation mechanism 154 . The live object tracing mechanism 152 may search a storage space to find all objects reachable from a root set. Since these objects may be used in the future, they are considered live objects. The live object tracing mechanism may mark these objects as live objects and further scan to find any other live objects these objects can reach. Objects other than live objects are considered garbage objects whose storage space may be reclaimed by the garbage reclamation mechanism 154 . In practice, the live object tracing mechanism and the garbage reclamation mechanism may be functionally interleaved and a reclamation technique may be strongly dependent on a live object marking technique. The garbage reclamation mechanism may reclaim garbage objects' space with or without moving live objects to a contingent area at one end of the storage space. In one embodiment, the garbage reclamation mechanism may be a part of a mutator rather than a garbage collector.
[0021] FIG. 2 is an exemplary flow diagram of a high-level process in which a stack trace cache is used during root set enumeration for garbage collection in a managed runtime system, according to an embodiment of the present invention. At block 210 , a garbage collection session may be initiated. At block 220 , stack enumeration may be performed using a stack trace cache. A stack trace cache may be created during the first stack enumeration for a thread to cache stack trace information when full stack unwinding is performed. During a later session of stack enumeration for the thread, part or all of cached stack trace information may be retrieved without conducting full stack unwinding, if it has not changed from the last stack enumeration session. For those frames whose trace information has changed, stack unwinding may be performed and the stack trace cache may be modified to accommodate updated stack trace information. At block 230 , root set enumeration in other storage areas may be performed to find live references in other storage areas such as registers. Blocks 220 and 230 may be performed concurrently, or in a reverse order without affecting the spirit of the present invention. At block 240 , live references obtained during stack enumeration and root set enumeration in other storage areas may be put together to form a root set. At block 250 , a storage space may be searched to mark and scan all live objects reachable from references in the root set. At block 260 , all those objects in the storage space that are not marked may be considered garbage and their space may be reclaimed.
[0022] FIG. 3 is a high-level functional block diagram of a stack enumeration mechanism that uses a stack trace cache, according to an embodiment of the present invention. The stack enumeration mechanism 135 may comprise a stack frame classifier 310 , a trace information caching mechanism 320 , a stack unwinding mechanism 330 , an unchanged trace detecting mechanism 340 , and an unchanged trace retrieving mechanism 350 . The stack frame classifier 310 may use the value of an “in-cache” tag of a stack frame in a stack 370 to decide if the stack frame is newly generated (i.e., not cached) or has already been in a stack trace cache 140 (i.e., cached). The “in-cache” tag may be set up by a compiler when a call is initiated. When the stack frame associated with the call is created for the first time, the compiler may set the value of the “in-cache” tag to be false. When the stack frame classifier classifies a stack frame as “not cached,” the stack unwinding mechanism 330 may perform normal stack unwinding for this frame (i.e., enumerate references in this frame and go to the next frame) and save live references in a root set 360 . Subsequently, the trace information caching mechanism 320 may cache the trace information of the frame into the stack trace cache and change the value of the “in-cache” tag of the stack frame from false to true, i.e., the stack frame becomes cached. The trace information caching mechanism may comprise a cache creator 325 that creates a stack trace cache when stack enumeration is first conducted. In the second or later session of stack enumeration, the cache creator may modify the stack trace cache to accommodate newly generated and/or updated stack frames. The stack trace cache may comprise two areas: an identification area to store identifiers of stack frames and a list area to store live references enumerated in each stack frame. In one embodiment, cached stack trace information may be represented by the following data structure:
struct CachedStackFrame { <eip, esp> id; /* eip and esp represent IP and SP, respectively */ Ref_List ref_list; /* cached enumerated references for this frame */ } cache[MAX_CALL_DEPTH];
where cache[MAX_CALL_DEPTH] array is a thread local object, that is, each thread has its own stack trace cache.
[0024] The trace information caching mechanism 320 may also comprise a identification component to identify each stack frame in a stack trace cache with values of a pair of registers, i.e., instruction pointer register (IP) and stack pointer register (SP). The IP may also be referred to as program counter (PC) and may be sufficient to point out source location and method name of a stack frame. The SP points to the current stack position. Since there may be multiple calls (with different stack positions) to a same method on the stack with the same IP (e.g., recursive calls), IP alone might not be able to identify a stack frame and SP may differentiate frames associated with these calls. Thus, using <IP, SP> may be desirable to identify a stack frame uniquely.
[0025] When the stack frame classifier 310 classifies a stack frame in the stack 370 as “cached” in the second or a later stack enumeration, the unchanged trace detecting mechanism 340 may search the stack trace cache from top to bottom and detect a starting frame of an unchanged portion of a stack trace. The starting frame of the unchanged portion in the stack trace cache may be detected when values of <IP, SP> of a frame in the stack trace cache is found to be equal to values of <IP, SP> of a current frame. When the starting frame of the unchanged portion is detected in the stack trace cache, the unchanged portion retrieving mechanism 350 may copy references in the unchanged portion directly to the root set 360 without further unwinding the stack.
[0026] FIG. 4 is an exemplary flow diagram of a process in which a stack trace cache is created and used to improve the performance of root set enumeration during garbage collection for a thread, according to an embodiment of the present invention. At block 410 , stack enumeration may be started. At block 415 , a decision whether this is the first stack enumeration for the thread may be made. If this is the first stack enumeration for the thread, a stack trace cache may be created for the thread at block 420 before a frame in a stack is evaluated for enumeration starting at block 425 ; otherwise, frames in the stack may be evaluated (one by one) directly starting at block 425 . At block 425 , a frame in the stack may be checked to see if the frame is tagged “cached” or “not cached.” If the frame is tagged “not cached,” normal stack enumeration may be conducted at block 430 , where stack unwinding may be started until a “cached” frame is reached in the stack. At block 435 , trace information about frames that have been enumerated at block 430 may be cached and the frames may be tagged as “cached.” The trace information may comprise an identifier for each frame and enumerated live references in each frame. The identifier of a frame may comprise values of IP and SP. At block 440 , the stack is checked to see if there are any frames left to be enumerated. If there are, the next frame in the stack may evaluated at block 425 and the process between block 425 and block 455 (not including block 455 ) may be reiterated until no frame is left in the stack. If a frame is found “cached” at block 425 , the stack trace cache may be searched to detect a starting point for an unchanged portion of a stack trace at block 445 . Once the starting point of the unchanged portion has been detected, references in frames following the starting point in the stack trace cache may be copied to a root set at block 450 , without further unwinding the stack. At block 455 , references from all frames in the stack may be obtained.
[0027] The advantages of using a stack trace cache for stack enumeration may further be illustrated by comparing the process of normal stack enumeration and the process of stack enumeration using a stack trace cache. The former is illustrated by Pseudo Code 1, and the latter is illustrated by Pseudo Code 2.
Pseudo Code 1. Normal Stack Enumeration © 2003 INTEL CORPORATION 1 Frame_Context context; 2 Ref_List allref = { }; /* stack enumeration result list */ 3 ... ... 4 context.initialize_to_gc_suspend_point( ); 5 while (not finished) { 6 normalize_if_necessary (&context); 7 /* perform normal stack enumeration */ 8 Ref_List rl = enumerate (&context); 9 /* copy enumerated references into result list */ 10 allref.append (rl); 11 finished = unwind_to_next_frame (&context); 12 }
[0028] In Pseudo Code 1, “Frame_Context” on line 1 represents a data structure of a call frame and contains information such as, for example, saved registers and spilled data. Before stack enumeration for a thread starts, “context” is initialized to a frame where the thread is suspended through “initialize_to_gc_suspend_point( ) in line 4 . “normalize_if_necessary( )” in line 6 normalizes a frame's SP from its suspended position to its base position, if necessary. Enumeration of references in this frame may start from normalized SP position. At the end of enumeration for this frame, “unwind_to_next_frame ( )”
Pseudo Code 2. Stack Enumeration Using Stack Trace Cache © 2003 INTEL CORPORATION 1 Frame_Context context; 2 Ref_List allref = { }; /* initialize stack enumeration result list */ 3 /* temporary cache to save stack frames not in cache */ 4 CachedStackFrame notcached[MAX_CALL_DEPTH]; 5 ... ... 6 context.initialize_to_gc_suspend_point( ); 7 while (not finished) { 8 if (context.in_cache == false) { 9 normalize_if_necessary (&context); 10 /* perform a normal enumeration */ 11 Ref_List rl = enumerate (&context); 12 /* copy enumerated references into result list */ 13 allref.append (rl); 14 /* add information of this frame to temporary cache */ 15 add_to_cache (notcached, <context.eip, context.esp>, rl); 16 finished = unwind_to_next_java_frame (&context); 17 } else { 18 /* find the starting point of reusable trace in cache */ 19 for (j = top; j >= 0; j−−) 20 if (context.<eip, esp> == cache[j].<eip, esp>) break; 21 /* copy enumerated references in cache to result list */ 22 for (; j >= 0; j−−) 23 allref.append (cache[j].ref_list); 24 /* stop unwinding, and jump out of loop */ 25 break; 26 } 27 } 28 /* update the cache with information in temporary cache */ 29 update_cache (cache, notcached);
unwinds the stack to a caller's frame in a call chain and retrieve the caller's context. The enumeration process continues until all frames in the call chain are enumerated. In other words, Pseudo Code 1 illustrates a process of full stack unwinding.
[0030] Pseudo Code 2 differs from Pseudo Code 1 by utilizing a stack trace cache (shown in lines 18 - 25 ) to increase the opportunity of avoiding part or all of stack unwinding. Therefore, overheads incurred by stack enumeration using a stack trace cache may be smaller than overheads incurred by stack enumeration through full stack unwinding.
[0031] FIGS. 5 ( a )-( d ) are schematic illustrations of the status of a stack trace cache in different sessions of stack enumeration for a thread, according to an embodiment of the present invention. FIG. 5 ( a ) illustrates a stack before the first session of stack enumeration is started. When stack enumeration is invoked for the first time for a thread, all frames in the stack are tagged “not cached” by a compiler. Thus, full stack unwinding is performed during the first stack enumeration, after which all frames are tagged with “cached” because a stack trace cache has been created and enumerated references for each frame has been cached in the stack trace cache, as shown in FIG. 5 ( b ). Each frame in the stack trace cache has an identification (id) area to store frame ids (i.e., values of IP and SP), and a list area to store enumerated references for each frame. FIG. 5 ( c ) illustrates status of each frame in the stack and the stack trace cache in a later session of stack enumeration. When this later session of stack enumeration is initiated, it may be not necessary to perform full stack unwinding because some frames (e.g., 4 frames corresponding to methods T.main, A.a, B.b, and C.c in FIG. 5 ( c )) remain unchanged in the stack and may be directly retrieved from the stack trace cache without conducting stack unwinding. Only information for another three frames (i.e., frames corresponding to methods G.g, H.h, and I.i) are not cached. Thus only partial stack unwinding (up to the frame corresponding to method B.b) is needed. Additionally, the stack trace cache may be modified to cache information on frames being enumerated during the partial stack enumeration. FIG. 5 ( d ) illustrates the status of the stack and the stack trace cache after this later session of stack enumeration.
[0032] Although the present invention is concerned with using stack trace caches for root set enumeration in a stack during garbage collection, persons of ordinary skill in the art wilt readily appreciate that the present invention may be used for reducing overheads incurred by any process involving stack unwinding such as, for example, exception handling, caller-callee relationship detecting, etc. Additionally, the present invention may be used for automatic garbage collection in any systems such as, for example, managed runtime environments running Java, C#, and/or any other programming languages.
[0033] Although an example embodiment of the present invention is described with reference to block and flow diagrams in FIGS. 1 - 5 ( d ) and Pseudo Codes 1-2, persons of ordinary skill in the art will readily appreciate that many other methods of implementing the present invention may alternatively be used. For example, the order of execution of the blocks in flow diagrams or steps in pseudo codes may be changed, and/or some of the blocks in block/flow diagrams and the steps in pseudo codes described may be changed, eliminated, or combined.
[0034] In the preceding description, various aspects of the present invention have been described. For purposes of explanation, specific numbers, systems and configurations were set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one skilled in the art having the benefit of this disclosure that the present invention may be practiced without the specific details. In other instances, well-known features, components, or modules were omitted, simplified, combined, or split in order not to obscure the present invention.
[0035] Embodiments of the present invention may be implemented on any computing platform, which comprises hardware and operating systems. The hardware may comprise a processor, a memory, a bus, and an I/O hub to peripherals. The processor may run a compiler to compile any software to the processor-specific instructions. Processing required by the embodiments may be performed by a general-purpose computer alone or in connection with a special purpose computer. Such processing may be performed by a single platform or by a distributed processing platform. In addition, such processing and functionality can be implemented in the form of special purpose hardware or in the form of software.
[0036] If embodiments of the present invention are implemented in software, the software may be stored on a storage media or device (e.g., hard disk drive, floppy disk drive, read only memory (ROM), CD-ROM device, flash memory device, digital versatile disk (DVD), or other storage device) readable by a general or special purpose programmable processing system, for configuring and operating the processing system when the storage media or device is read by the processing system to perform the procedures described herein. Embodiments of the invention may also be considered to be implemented as a machine-readable storage medium, configured for use with a processing system, where the storage medium so configured causes the processing system to operate in a specific and predefined manner to perform the functions described herein.
[0037] While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, which are apparent to persons skilled in the art to which the invention pertains are deemed to lie within the spirit and scope of the invention. | An arrangement is provided for using a stack trace cache when performing root set enumeration in a stack of a thread during garbage collection. During the first root set enumeration in the stack, full stack unwinding may be performed and a stack trace cache may be created to cache stack trace information relating to stack frames. Subsequent sessions of root set enumeration in the stack may access and copy parts or the entire cached stack trace information instead of performing full stack unwinding. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 USC §119(e) (1) of provisional application No. 60/534,298, filed Jan. 5, 2004.
This application is related to U.S. patent application Ser, No. 10/983,256, filed Nov. 4, 2004, which is incorporated herein by reference. This application claims priority from provisional application No. 60/534,298, filed Jan. 5, 2004.
BACKGROUND OF THE DISCLOSURE
Field of the Disclosure
This disclosure relates in general to circuit designs, and in particular to an improvement in the design of IEEE 1149.1 Tap interfaces of ICs and core circuits for improved communication of test, debug, emulation, programming, and general purpose I/O operations.
Today's ICs may contain many embedded 1149.1 Tap architectures (Tap domains). Some of these TAP domains are associated with intellectual property (IP) core circuits within the IC, and serve as access interfaces to test, debug, emulation, and programming circuitry within the IP cores. Other TAP domains may exist in the IC which are not associated with cores but rather to circuitry in the IC external of the cores. Further, the IC itself will typically contain a TAP domain dedicated for operating the boundary scan register associated with the input and output terminals of the ICs, according to IEEE std 1149.1.
FIG. 1 illustrates a simple example of an IEEE 1149.1 Tap domain 102 . The Tap domain includes a Tap controller 104 , an instruction register (IR) 106 , at least two data registers (DR) 108 , and multiplexer circuitry 110 . The Tap domain interface consists of a TDI input, a TCK input, a TMS input, a TRST input, and a TDO output. In response to TCK and TMS control inputs to Tap controller 104 , the Tap controller outputs control to capture data into and shift data through either the IR 106 from TDI to TDO or a selected DR 108 from TDI to TDO. The data shifted into IR 106 is updated and output on bus 114 to other circuits, and the data shifted into a DR 108 is updated and output on bus 112 to other circuits. DR 108 may also capture data from other circuits on bus 112 and IR 106 may capture data from other circuits on bus 114 . In response to a TRST input to the Tap controller 104 , the TAP controller, IR and DR are reset to known states. The structure and operation of IEEE 1149.1 Tap domain architectures like that of FIG. 1 are well known.
FIG. 2 illustrates the state diagram of the Tap controller 104 . All IEEE 1149.1 standard Tap controllers operate according to this state diagram. State transitions occur in response to TMS input and are clocked by the TCK input. The IEEE 1149.1 Tap state diagram is well known.
FIG. 3 illustrates an example system where a number of Tap domain 102 interfaces of ICs 306 - 312 or embedded cores 306 - 312 within ICs are connected together serially, via their TDI and TDO terminals, to form a scan path 302 from TDI 304 to TDO 306 . Each Tap domain 102 of the ICs/cores 306 - 312 are also commonly connected to TCK 314 , TMS 316 , and TRST 318 inputs. The scan path's TDI 304 , TDO 306 , TCK 314 , TMS 316 , and TRST 318 signals are coupled to a controller, which can serve as a test, debug, emulation, in-system-programming, and/or other application controller. While only four Tap domains 102 of ICs/cores 306 - 312 are shown, any number of IC/core Tap domains may exist in scan path 302 , as indicated by dotted line 322 . The scan path 302 arrangement of IC/core Tap domains is well known in the industry.
As seen in FIG. 3 , if data is to be input to Tap domain 102 of IC/core 312 from controller 320 it must serially pass through all leading Tap domains of ICs/cores 306 - 310 . Further, if data is to be output from Tap domain 102 IC/core 306 to controller 320 it must pass through all trailing Tap domains of ICs/cores 308 - 312 . Thus a data input and output latency exists between Tap domains of ICs/cores in scan path 302 and controller 320 . As will be seen later, the present disclosure provides a way to eliminate this data input and output latency by making use of the direct TMS 316 and/or TCK 314 connections between the Tap Domains of ICs/cores 306 - 312 and controller 320 . Having a direct connection for data input and output between the controller 320 and the Tap domains 102 , via the TMS and/or TCK connections, provides improved data communication throughput during test, debug, emulation, in-circuit-programming, and/or other type of operations. Further, using the direct TCK and/or TMS connections for data input and output between controller 320 and Tap domains 102 only involves the controller and the targeted Tap domain. Non-targeted Tap domains are not aware of or affected by the direct TMS and/or TCK communication.
SUMMARY OF THE DISCLOSURE
The present disclosure provides a method and apparatus of communicating data between; (1) an IC in a scan path and a controller of the scan path using the standard direct TMS and/or TCK connections that exists between the IC and controller, (2) a first IC of a scan path and a second IC of the scan path using the direct TMS and/or TCK connections between the lOs, (3) a first core circuit of a scan path in an IC and second core circuit of the scan path of the IC using the direct TMS and/or TCK connections between the cores. The TMS and/or TCK data I/O communication occurs while the Tap controller of the Tap domains of the IC/core are in a non-active state. Thus the TMS and/or TCK I/O communication does not disturb or modify the state of Tap domains of the IC/core in a scan path. The TMS and/or TCK I/O communication is achieved by adding circuitry to the IC/core and coupling the circuitry to the TMS and/or TCK terminals of the IC's/core's Tap domain. When enabled by control output from the IC's/core's Tap domain, the added circuitry becomes operable to input data from the Tap domain's TMS and/or TCK terminal or output data onto the Tap domain's TMS and/or TCK terminal. Conventional controllers 320 coupled to the TMS and TCK signals are improved, according to the present disclosure, such that they can input data from a Tap domain's TMS and/or TCK terminal and output data to a Tap domain's TMS and/or TCK terminal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a conventional IEEE 1149.1 Tap domain architecture.
FIG. 2 illustrates the state diagram of a conventional IEEE 1149.1 Tap controller.
FIG. 3 illustrates a conventional arrangement of ICs or cores within ICs with their Tap domains connected in a scan path and the scan path coupled to a controller.
FIG. 4 illustrates the scan path and controller arrangement of FIG. 3 adapted for TMS I/O communication according to the present disclosure.
FIG. 5 illustrates TMS I/O communication circuitry coupled to a Tap domain according to the present disclosure.
FIG. 6 illustrates the TMS I/O Circuit of FIG. 5 according to the present disclosure.
FIG. 7 illustrates circuitry and timing for receiving Manchester encoded TMS input data according to the present disclosure.
FIG. 8A illustrates a Manchester decoder state machine for receiving encoded TMS data according to the present disclosure.
FIG. 8B illustrates a state diagram of the operation of the Manchester decoder state machine of FIG. 8A .
FIG. 9 illustrates circuitry and timing for transmitting Manchester encoded TMS output data according to the present disclosure.
FIG. 10A illustrates a Manchester encoder state machine for transmitting encoded TMS data according to the present disclosure.
FIG. 10B illustrates a state diagram of the operation of the Manchester encoder state machine of FIG. 10A .
FIG. 11 illustrates how TMS I/O communication can occur while a Tap controller is in the Run Test/Idle state according to the present disclosure.
FIG. 12 illustrates how TMS I/O communication may occur while a Tap controller is in other states according to the present disclosure.
FIG. 13 illustrates TMS I/O communication occurring between and IC and a controller.
FIG. 14 illustrates TMS I/O communication occurring between two ICs.
FIG. 15 illustrates TMS I/O communication occurring between two core circuits within an IC.
FIG. 16 illustrates the scan path and controller arrangement of FIG. 3 adapted for TCK I/O communication according to the present disclosure.
FIG. 17 illustrates TCK I/O communication circuitry coupled to a Tap domain according to the present disclosure.
FIG. 18 illustrates the TCK I/O Circuit of FIG. 17 according to the present disclosure.
FIG. 19 illustrates circuitry and timing for receiving Manchester encoded TCK input data according to the present disclosure.
FIG. 20A illustrates a Manchester decoder state machine for receiving encoded TCK data according to the present disclosure.
FIG. 20B illustrates a state diagram of the operation of the Manchester decoder state machine of FIG. 20A .
FIG. 21 illustrates circuitry and timing for transmitting Manchester encoded TCK output data according to the present disclosure.
FIG. 22A illustrates a Manchester encoder state machine for transmitting encoded TCK data according to the present disclosure.
FIG. 22B illustrates a state diagram of the operation of the Manchester encoder state machine of FIG. 22A .
FIG. 23 illustrates how TCK I/O communication can occur while a Tap controller is in the Run Test/Idle state according to the present disclosure.
FIG. 24 illustrates how TCK I/O communication may occur while a Tap controller is in other states according to the present disclosure.
FIG. 25 illustrates TCK I/O communication occurring between and IC and a controller.
FIG. 26 illustrates TCK I/O communication occurring between two ICs.
FIG. 27 illustrates TCK I/O communication occurring between two core circuits within an IC.
DETAILED DESCRIPTION
FIG. 4 illustrates a scan path system 402 of ICs/cores that include Tap domains plus additional TMS I/O circuitry. The combination of the Tap domain and TMS I/O circuitry is referred to as TAPIO 416 . FIG. 4 is similar to FIG. 3 in regard to the way the TDI, TDO, TCK, TMS, and TRST signals are coupled between the TAPIOs 416 and controller 420 . Controller 420 is different from controller 320 in that it has been improved according to the present disclosure to include the capability of communicating data to and from the TAPIOs 416 via the TMS connection. Controller 420 maintains the conventional ability of controller 320 to communicate the Tap domains of the TAPIOs 416 using the standard IEEE 1149.1 serial protocol. As seen, the TMS connection between controller 420 and TAPIOs 416 is shown as a bidirectional signal path, as opposed to the unidirectional signal path of the TMS connection in FIG. 3 . When a TAPIO 416 is selected for sending data to the controller 420 according to the present disclosure, the TMS connection will become an output from the TAPIO and an input to the controller. When a TAPIO 416 is selected for receiving data from the controller 420 according to the present disclosure, the TMS connection will become an output from the controller and an input to the TAPIO. As can be seen in FIG. 4 , data is transferred directly between a selected TAPIO 416 and controller 420 . Therefore the data latency problem mentioned in regard with FIG. 3 does not exist in FIG. 4 .
Additionally, according to the present disclosure, one TAPIO of an IC/core in the scan path may communicate to another TAPIO of an IC/core in the scan path via the common bidirectional TMS connection. To achieve this mode of operation, the controller 420 selects one TAPIO to transmit and another TAPIO to receive. The controller then disables its TMS output driver so that the transmitting TAPIO can output on its TMS terminal to send data to the TMS terminal of the receiving TAPIO. Again, the data is directly transferred between the TAPIOs without the aforementioned latency problem.
FIG. 5 illustrates the TAPIO circuit 416 in more detail. As seen the TAPIO 416 consists of a Tap domain 502 , a TMS communication circuit 514 , And gates 506 - 508 , and a Clock Source circuit 528 . The Clock Source 528 can be a clock producing circuit within the IC or it can come from a pin of the IC. Tap domain 502 is similar to Tap domain 102 with the exception that it includes And gate 504 for detecting when the Tap controller 104 is in the Run Test/Idle (RTI) state 202 of FIG. 2 . The Tap controller 104 is a four bit state machine defining the 16 unique states shown in FIG. 2 . Each of the 16 Tap states is defined by a unique one of the four bit state machine codes. While not shown, the four inputs of the And gate 504 are inverted or not inverted to allow the And gate to detect, with a logic high output, when the Tap controller is in the Run Test/Idle state. For example, if the Run Test/Idle state has a four bit code of 0101, then the “0” inputs to And gate 504 will be inverted such that the And gate will receive all “1's” at its inputs so that it outputs a logic one when the Tap controller is in the Run Test/Idle state. This will be the case throughout the remainder of this specification for all And gates that are described for use in detecting Tap controller states. Also while And gates are shown being used to detect Tap controller states, other gating circuits may be used as well.
Further, Tap domain 502 differs from Tap domain 102 in that it includes an Enable TMS Output signal 510 and an Enable TMS Input signal 512 . The Enable TMS Output signal is set whenever the TMS communication circuit 514 is to perform a data output operation on TMS. The Enable TMS Input signal is set whenever the TMS communication circuit 514 is to perform a data input operation on TMS. As seen, the Enable TMS Input or Enable TMS Output signals can come, by design choice, from either the IR 106 via bus 114 or from a DR 108 via bus 112 .
When Enable TMS Output is set high and when the Tap controller 104 is in the Run Test/Idle (RTI) state 202 , the output of And gate 506 will go high to enable the TMS communications circuit 514 to perform a TMS output operation. When Enable TMS Input is set high and when the Tap controller 104 is in the Run Test/Idle (RTI) state, the output of And gate 508 will go high to enable the TMS communications circuit 514 to perform a TMS input operation. During either TMS communication operation, the Tap controller 104 remains in the Run Test/Idle state 202 .
TMS communication circuit 514 consists of a Frame Counter 516 , And gate 520 , TMS I/O Circuit 526 , Data Source 522 , and Data Destination 524 . The Frame Counter 516 is a data register 108 that can be scanned via TDI and TDO by the Tap controller 104 to load a count of the number of data frames that are to be sent from the Data Source 522 during a TMS output operation. A data frame in this disclosure is defined by a fixed number of transmitted data bits. After being scanned, and when enabled by the output of And gate 506 , the Frame Counter operates as a counter to count the number of data frames output on TMS. After all data frames have been sent out on TMS, the count complete (CC) output from the Frame Counter will go low to halt the TMS output operation of TMS I/O Circuit 526 , via And gate 520 . And gate 520 is gated on and off by the Enable TMS Output signal being high and low respectively. When gated off, the CC output from the Frame Counter cannot inadvertently, say during an 1149.1 operation that passes through the Run Test/Idle state, enable the TMS I/O Circuit 526 . The Frame Counter receives IR & Tap Control input via bus 530 for scanning in the count, control input 518 from the TMS I/O Circuit 526 for knowing when to count a frame, and a clock input from the Clock Source circuit 528 .
When enabled for inputting data from TMS, the TMS I/O Circuit 526 receives the TMS data and transfers it to the Data Destination circuitry 524 . Data Destination circuitry 524 may be any circuitry within an IC including but not limited to; (1) an address bus, (2) a data bus, (3) a Ram memory, (4) a Cache memory, (5) a register file, (6) a FIFO, (7) a register, (8) a processor, (9) a peripheral circuit, or (10) a bus coupled to circuitry external to the IC.
When enabled for outputting data on TMS, the TMS I/O Circuit 526 receives data from the Data Source circuitry 522 and outputs the data on TMS. Data Source circuitry 522 may be any circuitry within an IC including but not limited to; (1) an address bus, (2) a data bus, (3) a Ram memory, (4) a Rom memory, (5) a Cache memory, (6) a register file, (7) a FIFO, (8) a register, (9) a processor, (10) a peripheral circuit, or (11) a bus coupled to circuitry external to the IC.
FIG. 6 illustrates TMS I/O Circuit 526 in more detail. TMS I/O Circuit consists of a Data & Clock Decoder 604 , Input Register 602 , Data & Clock Encoder 614 , and Output Register 612 . As will be described in more detail later, the TMS communication is based on Manchester data communication whereby the clock and data signals are combined and transmitted together on TMS.
The function of the Data & Clock Decoder 604 is to receive a frame of Manchester encoded data on TMS terminal 316 , extract the data 606 and clock (CK) 608 components from the encoded data, and input the data 606 serially to Input Register 602 in response to the extract CK signal 608 . Enable (EN) signal 628 enables Input Register 602 to receive the data 606 . Input Register 602 , once filled with a complete serial data frame, outputs the data frame in parallel to Data Destination 524 via data bus 622 . CK signal 608 and Data In Ready control signal 606 controls the Data Destination to receive the parallel data from bus 622 . This process of receiving Manchester encoded serial data frames from TMS terminal 316 , decoding the serial data frames into parallel data patterns, and inputting the parallel data patterns to Data Destination 524 is repeated until the TMS input communication operation is completed.
The function of the Data & Clock Encoder 614 is to control the Output Register 612 , via Enable (EN) 626 , CK 618 and Data Output Ready 616 signals, to receive parallel data patterns from the Data Source 522 via bus 624 and output the data serially, via Data signal 620 , to the Data & Clock Encoder 614 . The Data & Clock Encoder 614 encodes the serial input data 620 with a clock from Clock Source 528 to produce a frame of serial Manchester encoded data to be output on TMS terminal 316 . This process of receiving a parallel data pattern from the Data Source 522 , converting the parallel data pattern into a frame of serial Manchester encoded data, and outputting the frame of serial Manchester encoded data onto TMS terminal 316 is repeated until all the parallel data patterns from Data Source 522 have been serially transmitted from TMS terminal 316 . As seen in FIG. 6 , the Data Out Ready signal 616 , which controls the input of parallel data patterns from the Data Source to the Output Register is also input to Frame Counter 516 to control the frame count. The count value in the Frame Counter 516 controls the number of parallel data patterns that are output as encoded serial frames from TMS 316 . The Frame Counter 516 decrements once per each Data Out Ready signal. As seen in FIG. 5 , when the frame count in Frame Counter 516 expires, the Frame Counter halts the TMS serial output operation by setting the count complete (CC) signal low.
FIG. 7 illustrates a timing example of the Data & Clock Decoder circuit 604 receiving Manchester encoded data on TMS terminal 316 . Manchester encoding, is well known and operates by sending an encoded signal as a pair of opposite bits. In the timing diagram, each pair of opposite bits are shown within boxes 708 . Each box represents a Manchester encoded signal. In one example of Manchester encoding, an encoded logic one is represented by a logic zero bit followed by a logic one bit, and an encoded logic zero is represented by a logic one bit followed by a logic zero bit. An alternate Manchester encoding reverses the polarity of the bit pair for an encoded logic one and encoded logic zero.
As seen the Manchester Decoder circuit 702 in circuit 604 , when enabled by Input Enable, becomes operable to receive Start signals 704 , four logic ones in this example, from TMS 316 . More than two consecutive logic ones is an illegal Manchester bit encode, therefore more than two logic ones can be used as an indication to initialize the Manchester Decoder for receiving serial frames of encoded TMS data. While two Start signals, each comprising two logic ones, are shown in this example, more Start signals may be used if desired. After recognizing the Start signals, the Manchester Decoder receives frames 1-N of Manchester encoded serial data from TMS 316 . The Manchester Decoder extracts the Data and CK components from each Manchester encoded bit in the frame and shifts the extracted Data into the Serial Input Parallel Output (SIPO) Register 602 . The Enable output from the Manchester Decoder enable the SIPO Register 602 to receive data. After each frame is decoded and shifted into SIPO Register 602 , the Manchester Decoder outputs the Data In Ready signal to Data Destination 524 . In response to the Data In Ready signal the Data Destination receives (stores and/or processes) the parallel output of Register 602 . This process continues until the Manchester Decoder receives Stop signals 706 , four logic zeros in this example, from TMS 316 . More than two consecutive logic zeros is an illegal Manchester bit encode, therefore more than two logic zeros can be used as an indication to cause the Manchester Decoder to stop receiving serial frames of encoded TMS data. While two Stop signals, each comprising two logic zeroes, are shown in this example, more Stop signals may be used if desired.
FIG. 8A illustrates a more detail example of Manchester Decoder circuit 702 . The Manchester Decoder 702 consists of a Manchester Decoder State Machine 802 and a Bit Counter 806 . The state machine 802 receives the TMS signal from TMS terminal 316 , a clock signal from Clock Source 528 , the Input Enable signal from And gate 508 , and a count complete (CC) signal from Bit Counter 804 . The state machine outputs a Data signal to SIPO Register 602 , a clock (CK) signal to SIPO Register 602 and Data Destination 524 , an Enable signal to SIPO Register 602 , the Data In Ready signal to Data Destination 524 , count control to Bit Counter 804 .
FIG. 8B illustrates the operation of state machine 802 . When the Input Enable signal is set high, the state machine begins sampling the TMS input for Start signals 704 . The frequency of the Clock Source is set sufficiently high to allow over-sampling of the TMS input signal. After Start signals are detected, the state machine begins sampling the TMS input to decode the Manchester encoded bit pairs 708 . Each time a bit pair is decoded, the appropriate Data value is clocked into SIPO Register 602 by the CK signal and the Bit Counter is clocked by counter control outputs. During the decode operation, the state machine monitors the CC input from the counter 804 . When a CC signal is detected, indicating that the number of bits received is equal to a full frame of bits, the state machine sets the Data In Ready signal high to enable the Data Destination to receive the full frame of bits from the parallel output from SIPO Register 602 . This process continues until the state machine receives the Stop signals 706 on the TMS signal, indicating the end of the transmission of Manchester encoded data frames. The state machine transitions to the Stop state and waits for the Input Enable signal to be set low by the Tap controller 104 exiting the Run Test/Idle state. A subsequent JTAG scan operation to either the DR 108 or the IR 106 register (i.e. the register from which it came) can set the Enable TMS input signal 512 low. When Input Enable goes low, the state machine 802 transitions back to the Input Enable state.
FIG. 9 illustrates a timing example of the Data & Clock Encoder circuit 614 outputting Manchester encoded data on TMS terminal 316 . In the timing diagram, each Start 704 , Data 708 , and Stop 706 bit signals are again illustrated as they were in FIG. 7 . As seen the Manchester Encoder circuit 902 in circuit 614 , when enabled by Output Enable, becomes operable to transmit Start signals 704 , four logic ones in this example, onto TMS 316 . Since the TMS terminal of an IC or Core is normally driven by a controller 420 , the controller must disable its drive of the TMS terminal to allow the TMS terminal of the IC or Core to become an output to drive the TMS of the controller during TMS output modes of operation. The disabling of the TMS controller output is indicated a “Z” in the timing diagram.
As seen, a 3-state buffer 904 inside the Manchester Encoder 902 becomes enabled during TMS output operation to drive the TMS terminal of the IC or core. After transmitting the Start signals, the Manchester Encoder loads parallel data into the Parallel Input Serial Output (PISO) Register 612 from the Data Source 522 and starts shifting the PISO Register 612 . Each bit shifted from the PISO Register to the Manchester Encoder is appropriately encoded as a Manchester bit pair signal 708 and transmitted out of the IC or core via the TMS terminal 316 . As seen the transmission of the Manchester bit pairs begins following the last transmitted Start signal. The Manchester Encoder combines the data and clock components together such that a Manchester Decoder 702 in the receiving controller 420 or other IC/core can extract the components back into separate data and clock signals. The Enable output from the Manchester Encoder enables the PISO Register 612 to load and shift out data. The serial data shifted out from one parallel load of the PISO Register forms one serial bit frame. After each frame is shifted out of the PISO Register 612 , the Manchester Encoder outputs the Data Out Ready signal to PISO Register 612 and Data Source 522 . In response to the Data Out Ready signal the PISO Register 612 inputs parallel data from Data Source 522 to began the next serial output frame that is encoded and output on TMS 316 . This process continues until the Output Enable input to the Manchester Encoder goes low, at which time the Manchester Encoder outputs Stop signals 706 , four logic zeros in this example, onto TMS 316 and disables the output buffer 904 , ending the TMS output operation.
FIG. 10A illustrates a more detail example of Manchester Encoder circuit 902 . The Manchester Encoder 902 consists of a Manchester Encoder State Machine 1002 , Bit Counter 1004 , TMS buffer 904 , and Clock Divider (CD) 906 . The state machine 1002 receives the Data output signal from PISO Register 612 , a clock signal from Clock Source 528 via Clock Divider 906 , the Output Enable signal from And gate 520 , and a count complete (CC) signal from Bit Counter 1004 . The state machine outputs a clock (CK) signal to PISO Register 612 and Data Source 522 , an Enable signal to PISO Register 612 , a Data Out Ready signal to PISO Register 612 and Data Source 522 , count control to Bit Counter 1004 , and encoded data to TMS 316 via buffer 904 .
FIG. 10B illustrates the operation of state machine 1002 . When the Output Enable signal is set high, the state machine enables the output buffer 904 and outputs Start signals 704 onto TMS 316 . Also the first parallel data pattern from Data Source 522 is loaded into PISO Register 612 . After sending the Start Bits, the state machine begins encoding the serial output data shifted from PISO Register 612 into Manchester encoded outputs on TMS 316 . The frequency of the CK output from the state machine 1002 is sufficiently less than the frequency of the clock output from the Clock Divider 906 to allow each data bit shifted out of PISO Register 612 to be encoded into the appropriate Manchester bit pair signal 708 . Each time an encoded bit pair is output on TMS 316 , the Bit Counter counts in response to control inputs from state machine 1002 . During the encoding operation, the state machine monitors the CC input from the Bit Counter 1004 . When a CC signal is detected, indicating that the last bit of the current bit frame is being shifted out of PISO Register 612 , the Data Out Ready signal is set to cause the next parallel data pattern from Data Source 522 to be loaded into PISO Register 612 to allow starting the next frame of data bit outputs from the Register 612 . Each data bit of each new frame of data loaded and shifted out of PISO Register 612 is encoded into Manchester bit pairs and output on TMS 316 . This process continues until the state machine 1002 detects the Output Enable signal going low, as a result of the count in Frame Counter 516 expiring and setting its frame count complete CC signal low, which in turn sets the Output Enable signal low via And gate 520 . When Output Enable is detected low, the state machine 1002 outputs the Stop signals 706 to indicate to controller 420 or other IC/core that the transmission of Manchester encoded data frames has come to an end. The state machine then disables output buffer 904 from driving the TMS terminal 316 and transitions to the Output Enable state of the diagram. When the TMS output operation is ended, the controller 420 enables its TMS output, transitions the Tap 104 from the Run Test/Idle state to set the Enable TMS Output signal low by a JTAG scan operation to either the DR 108 or the IR 106 register from whence it came.
Preferably the Clock Sources 528 in the transmitting and receiving devices (i.e. controller 420 , IC, or core) are of the same frequency. This would ensure that, by the use of Clock Divider 906 of Manchester Encoder 902 , the data encoded and output from a transmitting device's Manchester Encoder 902 will be at a bit rate easily over-sampled and decoded by the non-divided Clock Source 528 driving the Manchester Decoder 702 in a receiving device. A test that TMS data transmitted from Encoder 902 at the divided Clock Source rate is properly received by Decoder 702 at the full Clock Source rate can be achieved by simply enabling both circuits in the same device to operate simultaneously to transmit and receive data over their common TMS connection, then check that the data received in the Data Destination circuit 524 is correct.
As seen in the TMS Manchester communication timing diagrams of FIGS. 7 and 9 , the format of a TMS output operation is the same as the format a TMS input operation. Both formats include a header of at least two Start signals 704 followed by frames of Manchester data signals 708 followed by a trailer of at least two Stop signals 706 . This allows simple and standardized data communication between a TMS transmitting device (i.e. controller 420 , IC, or core) and a TMS receiving device (i.e. controller 420 , IC, or core). Other more complex formats may also be implemented as the need arises, such as formats that include frames for addressing and commanding operations to support more sophisticated communication needs.
FIG. 11 illustrates how a TMS I/O operation is initiated by the Tap controller transitioning into the Run Test/Idle state 202 . Prior to transitioning into the Run Test/Idle state, a scan operation will have been performed to set the Enable TMS Output 510 or Enable TMS Input 512 signal high, depending upon whether an TMS input or TMS output is desired. Also if it is a TMS output operation, the Frame Counter 516 is loaded with the frame count value. Once this setup procedure is accomplished, the Tap controller 104 is transitioned into the Run Test/Idle state as shown in FIG. 11 . Once in the Run Test/Idle state, the TCK clock is halted at a low logic level. The RTI signal is set which enables And Gates 506 and 508 to pass the Enable TMS Input or Output signals 510 and 512 to TMS communication circuit 514 . The selected TMS input or TMS output operation begins at time 1102 and is executed during time 1104 as shown in FIG. 11 while the Tap is in the Run Test/Idle state with the TCK halted. When the TMS input or TMS output operation is competed at time 1106 , the TMS and TCK signal may once again be operated by the controller 420 to transition the Tap controller 104 through its states. As can be seen, with the Tap controller in the Run Test/Idle state and with the TCK halted, TMS input and TMS output operations are completely transparent to the Tap controller and all IEEE 1149.1 circuitry connected to the Tap controller. While this example halts the TCK at a low logic level, the TCK could be halted at a high logic level as well.
FIG. 12 is provided to illustrate that other Tap controller states, other than Run Test/Idle, may be used to perform TMS input and TMS output operations. For example, the Shift-DR state 1202 , the Pause-DR state 1204 , the Shift-IR state 1206 , and the Pause-IR state 1208 all may be used in addition to the Run Test/Idle state for TMS input and output operation modes. To use these additional Tap controller states as states in which TMS input and output operations may be performed is simply a matter of providing And gates 1210 to decode when the Tap controller is in one of the states, as And gate 504 did for detecting the Run Test/Idle state, and providing an Or gate 1212 for indicating when any of the And gate 1210 outputs are high. The output of the Or gate 1212 would be substituted for the RTI output of And gate 504 in FIG. 5 and input to And gates 506 and 508 . With this substitution made, the TCK could be halted in any one of these states to allow the TMS I/O operation to be started, executed, and stopped, as was shown and described in regard to the Run Test/Idle state of FIG. 11 . While And/Or gating is shown in this example, other gating circuitry types could be used as well to detect the other Tap states.
FIG. 13 illustrates an example of the TMS I/O operation of the present disclosure being performed between an IC 1302 of a scan path 402 and a controller 420 as shown in FIG. 4 . If the controller is performing a TMS output operation, the IC will be performing a TMS input operation to receive the data from the controller via the TMS connection. If the IC is performing a TMS output operation, the controller will be performing a TMS input operation to receive the data from the IC via the TMS connection.
FIG. 14 illustrates an example of the TMS I/O operation of the present disclosure being performed between a first 1402 and second 1404 IC of a scan path 402 . If IC 1402 is performing a TMS output operation, IC 1404 will be performing a TMS input operation to receive the data from IC 1402 via the TMS connection. If IC 1404 is performing a TMS output operation, IC 1402 will be performing a TMS input operation to receive the data from IC 1404 via the TMS connection. During these operations, the TMS output of controller 420 of FIG. 4 will need to be disabled to allow the TMS terminal of the outputting IC to drive the TMS connection between the lOs.
FIG. 15 illustrates an example of the TMS I/O operation of the present disclosure being performed between a first 1502 and second 1504 core circuit within an IC of scan path 402 . If core 1502 is performing a TMS output operation, core 1504 will be performing a TMS input operation to receive the data from core 1502 via the TMS connection. If core 1504 is performing a TMS output operation, core 1502 will be performing a TMS input operation to receive the data from core 1504 via the TMS connection. During these operations, the TMS output of controller 420 of FIG. 4 , or the output of an internal buffer in the IC being driven by the TMS output of controller 420 will need to be disabled to allow the TMS terminal of the outputting core to drive the TMS connection between the cores.
In all of the examples in FIGS. 13-15 , the TMS I/O data communication between the devices (IC and controller, IC and IC, core and core) is performed directly and without introducing any communication latency by having to pass the communicated data through any other devices. Further, devices not involved in the TMS I/O communication are not effected by the TMS I/O communication.
FIG. 16 illustrates a scan path system 1602 of ICs/cores that include Tap domains plus additional TCK I/O circuitry. The combination of the Tap domain and TCK I/O circuitry is referred to as TAPIO 1616 . FIG. 16 is similar to FIGS. 3 and 4 in regard to the way the TDI, TDO, TCK, TMS, and TRST signals are coupled between the TAPIOs 1616 and controller 1620 . FIG. 16 is different from FIG. 4 in that communication is provided between the controller 1620 and TAPIO 1616 via the TCK signal 314 instead of via the TMS signal 316 . Controller 1620 is different from controller 420 of FIG. 4 in that it has been improved according to the present disclosure to include the capability of communicating data to and from the TAPIOs 1616 via the TCK connection. As with controller 420 , controller 1620 maintains the conventional ability of controller 320 to communicate the Tap domains of the TAPIOs 1616 using the standard IEEE 1149.1 serial protocol. As seen, the TCK connection between controller 1620 and TAPIOs 1616 is shown as a bidirectional signal path, as opposed to the unidirectional signal path of the TCK connection in FIG. 3 . When a TAPIO 1616 is selected for sending data to the controller 1620 according to the present disclosure, the TCK connection will become an output from the TAPIO and an input to the controller. When a TAPIO 1616 is selected for receiving data from the controller 1620 according to the present disclosure, the TCK connection will become an output from the controller and an input to the TAPIO. As can be seen in FIG. 16 , data is transferred directly between a selected TAPIO 1616 and controller 1620 . Therefore the data latency problem mentioned in regard with FIG. 3 does not exist in FIG. 16 .
Additionally, according to the present disclosure, one TAPIO of an IC/core in the scan path may communicate to another TAPIO 1616 of an IC/core in the scan path via the common bidirectional TCK connection. To achieve this mode of operation, the controller 1620 selects one TAPIO to transmit and another TAPIO to receive. The controller then disables its TCK output driver so that the transmitting TAPIO can output on its TCK terminal to send data to the TCK terminal of the receiving TAPIO. Again, the data is directly transferred between the TAPIOs without the aforementioned latency problem.
FIG. 17 illustrates the TAPIO circuit 1616 in more detail. As seen the TAPIO 1616 consists of a Tap domain 502 , a TCK communication circuit 1714 , And gates 506 - 508 , a Clock Source circuit 528 , and a D flip flop 1702 . The Clock Source 528 can be a clock producing circuit within the IC or it can come from a pin of the IC. Tap domain 502 is similar to Tap domain 102 with the exception that it includes the previously described And gate 504 for detecting when the Tap controller 104 is in the Run Test/Idle (RTI) state 202 of FIG. 2 , and that it includes an Enable TCK Output signal 1710 and an Enable TCK Input signal 1712 . D flip flop 1702 has a data (D) input and a reset (R) input coupled to the output of And gate 504 , an inverted clock input coupled to TCK 314 , and a data (Q) output (RTI) coupled to an input of And gates 506 and 508 . The Enable TCK Output signal is set whenever the TCK communication circuit 1714 is to perform a data output operation on TCK. The Enable TCK Input signal is set whenever the TCK communication circuit 1714 is to perform a data input operation on TCK. As seen, the Enable TCK Input or Enable TCK Output signals can come, by design choice, from either the IR 106 via bus 114 or from a DR 108 via bus 112 .
When the Tap controller 104 is in the Run Test/Idle state 202 the output of And gate 504 will be high, placing a logic one on the data input and the reset input of D flip flop 1702 . With the Tap controller in Run Test/idle, the RTI output of D flip flop 1702 will go high on the falling edge of TCK via the logic one output from And gate 504 . When the Tap controller exits from the Run Test/Idle state, the RTI output of And gate 504 goes low by the output of And gate 504 going low, which resets the RTI output of D flip flop 1702 to a logic zero.
When Enable TCK Output is set high and the RTI output of D flip flop 1702 is high, the output of And gate 506 will go high to enable the TCK communications circuit 1714 to perform a TCK output operation. When Enable TCK Input is set high and the RTI output of D flip flop 1702 is high, the output of And gate 508 will go high to enable the TCK communications circuit 1714 to perform a TCK input operation. During either TCK communication operation, the Tap controller 104 remains in the Run Test/Idle state 202 since the TMS signal 316 input from controller 1620 will be held low.
The structure and operation of TCK communication circuit 1714 is the same as TMS communication circuit 514 of FIG. 5 with the exception that TCK I/O Circuit 1726 has been substituted for TMS I/O Circuit 526 .
When enabled for inputting data from TCK, the TCK I/O Circuit 1726 receives the TCK data and transfers it to the Data Destination circuitry 524 . Data Destination circuitry 524 may be any circuitry within an IC including but not limited to; (1) an address bus, (2) a data bus, (3) a Ram memory, (4) a Cache memory, (5) a register file, (6) a FIFO, (7) a register, (8) a processor, (9) a peripheral circuit, or (10) a bus coupled to circuitry external to the IC.
When enabled for outputting data on TCK, the TCK I/O Circuit 1726 receives data from the Data Source circuitry 522 and outputs the data on TCK. Data Source circuitry 522 may be any circuitry within an IC including but not limited to; (1) an address bus, (2) a data bus, (3) a Ram memory, (4) a Rom memory, (5) a Cache memory, (6) a register file, (7) a FIFO, (8) a register, (9) a processor, (10) a peripheral circuit, or (11) a bus coupled to circuitry external to the IC.
FIG. 18 illustrates TCK I/O Circuit 1726 in more detail. TCK I/O Circuit 1726 is the same as TMS I/O Circuit 526 of FIG. 6 with the exception that it uses the TCK signal 314 for communication instead of the TMS signal 316 .
As described previously in regard to TMS I/O Circuit 526 , the function of the Data & Clock Decoder 604 of FIG. 18 is to receive a frame of Manchester encoded data on TCK terminal 314 , extract the data and clock (CK) components from the encoded data, and input the data serially to Input Register 602 in response to the extract CK signal. Input Register 602 , once filled with a complete serial data frame, outputs the data frame in parallel to Data Destination 524 via data bus 622 . CK signal and Data In Ready control signal controls the Data Destination to receive the parallel data from bus 622 . This process of receiving Manchester encoded serial data frames from TCK terminal 314 , decoding the serial data frames into parallel data patterns, and inputting the parallel data patterns to Data Destination 524 is repeated until the TCK input communication operation is completed.
As described previously in regard to TMS I/O Circuit 526 , the function of the Data & Clock Encoder 614 of FIG. 18 is to control the Output Register 612 to receive parallel data patterns from the Data Source 522 via bus 624 and output the data serially to the Data & Clock Encoder 614 . The Data & Clock Encoder 614 encodes the serial input data 620 with a clock from Clock Source 528 to produce a frame of serial Manchester encoded data to be output on TCK terminal 314 . This process of receiving a parallel data pattern from the Data Source 522 , converting the parallel data pattern into a frame of serial Manchester encoded data, and outputting the frame of serial Manchester encoded data onto TCK terminal 314 is repeated until all the parallel data patterns from Data Source 522 have been serially transmitted from TCK terminal 314 . As seen in FIG. 18 , the Data Out Ready signal 616 , which controls the input of parallel data patterns from the Data Source to the Output Register is also input to Frame Counter 516 to control the frame count. The count value in the Frame Counter 516 controls the number of parallel data patterns that are output as encoded serial frames from TCK 316 . The Frame Counter 516 decrements once per each Data Out Ready signal. As seen in FIG. 17 , when the frame count in Frame Counter 516 expires, the Frame Counter halts the TCK serial output operation by setting the count complete (CC) signal to And gate 520 low.
FIG. 19 illustrates a timing example of the Data & Clock Decoder circuit 604 receiving Manchester encoded data on TCK terminal 314 . The timing example is the same as that described previously in FIG. 7 , with the exception that the TCK signal 314 is used for communication instead of the TMS signal 316 . Also it is seen that the Input Enable goes high on the falling edge 1902 of TCK 314 . Referring back to FIG. 17 , the output of D flip flop 1702 is set high on the falling edge of TCK 314 when the Tap is in the RTI state 202 , which in turn sets the Input Enable output of And gate 508 high if Enable TCK Input 1712 is high. Use of the falling edge of TCK to initiate the TCK input operation allows the operation to start after TCK has transitioned to a low logic state which allows the Start signals 704 (four logic one's in this example) on TCK to be more easily recognized by the Data & Clock Decoder circuit 604 .
As seen the Manchester Decoder circuit 702 in circuit 604 , when enabled by Input Enable, becomes operable to receive Start signals 704 , four logic ones in this example, from TCK 316 . After recognizing the Start signals, the Manchester Decoder receives frames 1-N of Manchester encoded serial data from TCK 314 . The Manchester Decoder extracts the Data and CK components from each Manchester encoded bit 708 in the frame and shifts the extracted Data into the Serial Input Parallel Output (SIPO) Register 602 . The Enable output from the Manchester Decoder enable the SIPO Register 602 to receive data. After each frame is decoded and shifted into SIPO Register 602 , the Manchester Decoder outputs the Data In Ready signal to Data Destination 524 . In response to the Data In Ready signal the Data Destination receives (stores and/or processes) the parallel output of Register 602 . This process continues until the Manchester Decoder receives Stop signals 706 , four logic zeros in this example, from TCK 314 , to cause the Manchester Decoder to stop receiving serial frames of encoded TCK data.
FIG. 20A illustrates a more detail example of Manchester Decoder circuit 702 , which is the same as that described in FIG. 8A with the exception that the TCK signal 314 is substituted for the TMS 316 signal. The Manchester Decoder 702 consists of a Manchester Decoder State Machine 802 and a Bit Counter 806 . The state machine 802 receives the TCK signal from TCK terminal 314 , a clock signal from Clock Source 528 , the Input Enable signal from And gate 508 , and a count complete (CC) signal from Bit Counter 804 . The state machine outputs a Data signal to SIPO Register 602 , a clock (CK) signal to SIPO Register 602 and Data Destination 524 , an Enable signal to SIPO Register 602 , the Data In Ready signal to Data Destination 524 , count control to Bit Counter 804 .
FIG. 20B illustrates the operation of state machine 802 , which is the same as described previously in regard to FIG. 8B . When the Input Enable signal is set high, the state machine begins sampling the TCK input for Start signals 704 . The frequency of the Clock Source is set sufficiently high to allow over-sampling of the TCK input signal. After Start signals are detected, the state machine begins sampling the TCK input to decode the Manchester encoded bit pairs 708 . Each time a bit pair is decoded, the appropriate Data value is clocked into SIPO Register 602 by the CK signal and the Bit Counter is clocked by counter control outputs. During the decode operation, the state machine monitors the CC input from the counter 804 . When a CC signal is detected, indicating that the number of bits received is equal to a full frame of bits, the state machine sets the Data In Ready signal high to enable the Data Destination to receive the full frame of bits from the parallel output from SIPO Register 602 . This process continues until the state machine receives the Stop signals 706 on the TCK signal, indicating the end of the transmission of Manchester encoded data frames. The state machine transitions to the Stop state and waits for the Input Enable signal to be set low by the Tap controller 104 exiting the Run Test/Idle state. A subsequent JTAG scan operation to either the DR 108 or the IR 106 register (i.e. the register from which it came) can set the Enable TCK input signal 1712 low. When Input Enable goes low, the state machine 802 transitions back to the Input Enable state.
FIG. 21 illustrates a timing example of the Data & Clock Encoder circuit 614 outputting Manchester encoded data on TCK terminal 314 . The timing example is the same as that described previously in FIG. 9 , with the exception that the TCK signal 314 is used for communication instead of the TMS signal 316 . Also it is seen that the Output Enable goes high on the falling edge 2102 of TCK 314 . Referring back to FIG. 17 , the output of D flip flop 1702 is set high on the falling edge of TCK 314 when the Tap is in the RTI state 202 , which in turn sets the Output Enable output of And gate 506 high if Enable TCK Output 1710 is high. Use of the falling edge of TCK to initiate the TCK output operation allows the operation to start after TCK has transitioned to a low logic state and the controller 1620 has disabled (“Z”) its TCK output driver.
In the timing diagram, the Start 704 , Data 708 (of frames 1-N), and Stop 706 signals are again illustrated as they were in FIG. 9 . As seen, the Manchester Encoder circuit 902 in circuit 614 , when enabled by Output Enable, becomes operable to transmit Start signals 704 , four logic ones in this example, onto TCK 314 . As mentioned above, the controller 1620 will have disabled its TCK output driver to allow the output buffer 904 of the Manchester Encoder circuit 902 to drive the TCK 314 terminal.
After transmitting the Start signals, the Manchester Encoder loads parallel data into the Parallel Input Serial Output (PISO) Register 612 from the Data Source 522 and starts shifting the PISO Register 612 . Each bit shifted from the PISO Register to the Manchester Encoder is appropriately encoded as a Manchester bit pair signal 708 and transmitted out of the IC or core via the TCK terminal 314 . The Manchester Encoder combines the data and clock components together such that a Manchester Decoder 702 in the receiving controller 420 or other IC/core can extract the components back into separate data and clock signals. The Enable output from the Manchester Encoder enables the PISO Register 612 to load and shift out data. The serial data shifted out from one parallel load of the PISO Register forms one serial bit frame. After each frame is shifted out of the PISO Register 612 , the Manchester Encoder outputs the Data Out Ready signal to PISO Register 612 and Data Source 522 . In response to the Data Out Ready signal the PISO Register 612 inputs parallel data from Data Source 522 to began the next serial output frame that is encoded and output on TCK 314 . This process continues until the Output Enable input to the Manchester Encoder goes low, at which time the Manchester Encoder outputs Stop signals 706 , four logic zeros in this example, onto TCK 314 and disables the output buffer 904 , ending the TCK output operation.
FIG. 22A illustrates a more detail example of Manchester Encoder circuit 902 , which is the same as that described in FIG. 10A with the exception that the TCK signal 314 is substituted for the TMS 316 signal. The Manchester Encoder 902 consists of a Manchester Encoder State Machine 1002 , Bit Counter 1004 , TCK buffer 904 , and Clock Divider (CD) 906 . The state machine 1002 receives the Data output signal from PISO Register 612 , a clock signal from Clock Source 528 via Clock Divider 906 , the Output Enable signal from And gate 520 , and a count complete (CC) signal from Bit Counter 1004 . The state machine outputs a clock (CK) signal to PISO Register 612 and Data Source 522 , an Enable signal to PISO Register 612 , a Data Out Ready signal to PISO Register 612 and Data Source 522 , count control to Bit Counter 1004 , and encoded data to TCK 314 via buffer 904 .
FIG. 22B illustrates the operation of state machine 1002 . When the Output Enable signal is set high, the state machine enables the output buffer 904 and outputs Start signals 704 onto TCK 314 . Also the first parallel data pattern from Data Source 522 is loaded into PISO Register 612 . After sending the Start Bits, the state machine begins encoding the serial output data shifted from PISO Register 612 into Manchester encoded outputs on TCK 314 . The frequency of the CK output from the state machine 1002 is sufficiently less than the frequency of the clock output from the Clock Divider 906 to allow each data bit shifted out of PISO Register 612 to be encoded into the appropriate Manchester bit pair signal 708 . Each time an encoded bit pair is output on TCK 314 , the Bit Counter counts in response to control inputs from state machine 1002 . During the encoding operation, the state machine monitors the CC input from the Bit Counter 1004 . When a CC signal is detected, indicating that the last bit of the current bit frame is being shifted out of PISO Register 612 , the Data Out Ready signal is set to cause the next parallel data pattern from Data Source 522 to be loaded into PISO Register 612 to allow starting the next frame of data bit outputs from the Register 612 . Each data bit of each new frame of data loaded and shifted out of PISO Register 612 is encoded into Manchester bit pairs and output on TCK 314 . This process continues until the state machine 1002 detects the Output Enable signal going low, as a result of the count in Frame Counter 516 expiring and setting its frame count complete CC signal low, which in turn sets the Output Enable signal low via And gate 520 . When Output Enable is detected low, the state machine 1002 outputs the Stop signals 706 to indicate to controller 1620 or other IC/core that the transmission of Manchester encoded data frames has come to an end. The state machine then disables output buffer 904 from driving the TCK terminal 314 and transitions to the Output Enable state of the diagram. When the output operation is ended, the controller 1620 enables its TCK output and sets the Enable TCK Output signal low by a JTAG scan operation to either the DR 108 or the IR 106 register from whence it came.
As with the TMS I/O communication, it is preferable that the Clock Sources 528 in transmitting and receiving devices (i.e. controller 1620 , IC, or core) be at the same frequency. This would ensure that, by the use of Clock Divider 906 of Manchester Encoder 902 , the data encoded and output from a transmitting device's Manchester Encoder 902 will be at a bit rate easily over-sampled and decoded by the non-divided Clock Source 528 driving the Manchester Decoder 702 in a receiving device. A test that TCK data transmitted from Encoder 902 at the divided Clock Source rate is properly received by Decoder 702 at the full Clock Source rate can be achieved by performing the test previously describe with the TMS I/O communication.
As seen in the TCK Manchester communication timing diagrams of FIGS. 19 and 21 , the format of a TCK output operation is the same as the format a TCK input operation. Both formats include a header of Start signals 704 followed by frames of Manchester data signals 708 followed by a trailer of Stop signals 706 . This allows simple and standardized data communication between a TCK transmitting device (i.e. controller 1620 , IC, or core) and a TCK receiving device (i.e. controller 1620 , IC, or core). As with the previously described TMS communication of FIGS. 7 and 9 , TCK communication may be expanded to include other more complex formats as the need arises, such as formats that include frames for addressing and commanding operations.
FIG. 23 illustrates how a TCK I/O operation is initiated by the Tap controller transitioning into the Run Test/Idle state 202 . Prior to transitioning into the Run Test/Idle state, a scan operation will have been performed to set the Enable TCK Output 1710 or Enable TCK Input 1712 signal high, depending upon whether a TCK input or TCK output is desired. Also if it is a TCK output operation, the Frame Counter 516 is scanned to load the frame count value. Once this setup procedure is accomplished, the Tap controller 104 is transitioned into the Run Test/Idle state as shown in FIG. 23 . Once in the Run Test/Idle state, and after the RTI output of D flip flop 1702 goes high, the selected TCK input or output operation can begin.
The RTI signal is set high on the falling edge of TCK at time 2302 which enables And Gates 506 and 508 to pass the Enable TCK Input or Output signals 1710 and 1712 to TCK communication circuit 1714 . If a TCK output operation is to be performed, the controller 1620 will disable its TCK output driver after the falling edge of TCK at time 2302 and before time 2304 to allow a transmitting device to drive the TCK signal 314 . The selected TCK input or TCK output operation begins at time 2304 and is executed during time 2306 as shown in FIG. 23 while the Tap is in the Run Test/Idle state. When the TCK input or TCK output operation is competed at time 2308 , the TCK signal may once again be driven by the controller 1720 to conventionally operate Tap controller 104 using IEEE 1149.1 protocols. As can be seen, with the Tap controller in the Run Test/Idle state with TMS held low, TCK input and TCK output operations are completely transparent to the Tap controllers and all IEEE 1149.1 circuitry connected to Tap controllers.
FIG. 24 is provided to illustrate that other Tap controller states, other than Run Test/Idle, may be used to perform TCK input and TCK output operations. For example, the Pause-DR state 1204 or the Pause-IR state 1208 may be used in addition to the Run Test/Idle state 202 for TCK input and output operation modes. To use these additional Tap controller states as states in which TCK input and output operations may be performed is simply a matter of providing And gates 2402 to detect when the Tap controller is in one of the states, as And gate 504 did for detecting the Run Test/Idle state, and providing an Or gate 2404 for indicating when any of the And gate 2402 outputs are high. The output of the Or gate 2404 would be substituted for the output of And gate 504 in FIG. 17 as input to D flip flop 1702 . The output of D flip flop 1702 , renamed “TCK I/O State” in FIG. 24 , would maintain its connection to And gate 506 and 508 as shown in FIG. 17 . With this substitution made, the Tap controller 104 could be transitioned into any one of these states, and held there by asserting a low on TMS, to allow a TCK I/O operation to be started, executed, and stopped, as was shown and described in regard to the Run Test/Idle state of FIG. 23 . While it is possible to also use the Shift-DR state 1202 and Shift-IR state 1206 for TCK input and output operations, as was shown and described in the TMS input and output operations of FIG. 12 , one must be aware that data will be shifting through the lOs/cores of scan path 1602 from TDI to TDO during the TCK input or output operations, since the TCK signal will be active. This may or may not be a desired situation and is therefore left up to the user of the disclosure to determined whether TCK input and output operations are also allowed in the Shift-DR and Shift-IR Tap states. If allowed, then additional And gates 2402 would be assigned to detect these additional Tap states and the Or gate 2404 would be equipped with additional inputs for receiving the outputs from the additional And gates 2402 .
FIG. 25 illustrates an example of the TCK I/O operation of the present disclosure being performed between an IC 2502 of a scan path 1602 and a controller 1620 as shown in FIG. 16 . If the controller is performing a TCK output operation, the IC will be performing a TCK input operation to receive the data from the controller via the TCK connection. If the IC is performing a TCK output operation, the controller will be performing a TCK input operation to receive the data from the IC via the TCK connection.
FIG. 26 illustrates an example of the TCK I/O operation of the present disclosure being performed between a first 2602 and second 2604 IC of a scan path 1602 . If IC 2602 is performing a TCK output operation, IC 2604 will be performing a TCK input operation to receive the data from IC 2602 via the TCK connection. If IC 2604 is performing a TCK output operation, IC 2602 will be performing a TCK input operation to receive the data from IC 2604 via the TCK connection. During these operations, the TCK output of controller 1620 of FIG. 16 will need to be disabled to allow the TCK terminal of the outputting IC to drive the TCK connection between the lOs.
FIG. 27 illustrates an example of the TCK I/O operation of the present disclosure being performed between a first 2702 and second 2704 core circuit within an IC of scan path 1602 . If core 2702 is performing a TCK output operation, core 2704 will be performing a TCK input operation to receive the data from core 2702 via the TCK connection. If core 2704 is performing a TCK output operation, core 2702 will be performing a TCK input operation to receive the data from core 2704 via the TCK connection. During these operations, the TCK output of controller 1620 of FIG. 16 , or the output of an internal buffer in the IC being driven by the TCK output of controller 1620 will need to be disabled to allow the TCK terminal of the outputting core to drive the TCK connection between the cores.
In all of the examples in FIGS. 25-27 , the TCK I/O data communication between the devices (IC and controller, IC and IC, core and core) is performed directly and without introducing any communication latency by having to pass the communicated data through any other devices. Further, devices not involved in the TCK I/O communication are not effected by the TCK I/O communication.
While the Manchester encoding and decoding circuits described herein to achieve the TMS and TCK I/O communication have been described as being state machines operating synchronous to a clock source 528 , the disclosure is not limited to a particular type of Manchester encoding and decoding circuit. Indeed, other types of Manchester encoding and decoding circuits may be readily substituted for the example circuits shown herein and used to achieve the Manchester based TMS and TCK I/O communication objective of the present disclosure.
While the TMS and TCK I/O communication circuit examples were shown as residing in ICs and/or cores, it should be clear that similar TMS and TCK I/O communication circuits or software that can emulate the TMS and TCK I/O communication circuit functionality also resides in the controllers that connect to the ICs and/or cores to enable the controllers to communicate with the ICs and/or cores during TMS and TCK I/O communication operations.
Although the present disclosure has been described in detail, it should be understood that various changes, substitutions and alterations may be made without departing from the spirit and scope of the disclosure as defined by the appended claims. | The present disclosure describes using the JTAG Tap's TMS and/or TCK terminals as general purpose serial Input/Output (I/O) Manchester coded communication terminals. The Tap's TMS and/or TCK terminal can be used as a serial I/O communication channel between; (1) an IC and an external controller, (2) between a first and second IC, or (3) between a first and second core circuit within an IC. The use of the TMS and/or TCK terminal as serial I/O channels, as described, does not effect the standardized operation of the JTAG Tap, since the TMS and/or TCK I/O operations occur while the Tap is placed in a non-active steady state. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
This is the 35 USC 371 national stage of international application PCT/NO97/00012 filed on Jan. 15, 1997, which designated the United States of America.
FIELD OF THE INVENTION
The invention concerns a method and a system for automatic identification of ammunition type in connection with guns both with and without firing computers. The method and the system are particularly, but not exclusively, intended for firing shells from armoured vehicles. The invention also concerns an application of the system for calculation of firing data.
BACKGROUND OF THE INVENTION
Many types of ammunition are often used today, where the different ammunition types have different departure speeds and weights. The result of this is that the different ammunition types have differing ballistic characteristics. At present the ammunition type is normally manually fed by the person who loads the gun. As a rule this process is implemented by the person pressing a key or operating a switch on a control panel associated thereto. Ballistic data concerning the ammunition are then retrieved from the control panel, which data are either presented to the person who has to calculate the firing parameters or are transmitted directly to a firing computer which performs these calculations and controls the firing. When firing takes place with a gun employing this kind of manual feeding of ammunition type, it is a common occurrence for the person loading the gun and feeding in the ammunition type to place one type of ammunition in the gun and key in another type of ammunition or perhaps forget to key in the ammunition type. One result of this is that the target is not hit since the ballistic data which form the basis of the firing parameters, and the actual ballistic data for ammunition deviate from each other. This kind of faulty feeding in of information occurs relatively frequently, and up to 10% of the entries are assumed to be wrong. An example of a control panel currently in use is illustrated in FIG. 1.
U.S. Pat. No. 5,233,125 discloses a system for automatic loading, and comprises a device for identification of ammunition type and selection of the correct ballistic data which are transmitted to a computer for control of the firing. This identification device is based on the bar code principle, which implies that all ammunition must be provided with bar codes to enable the identification device to work. If bar codes are not applied to the ammunition which has to be used, an operator must manually feed in the necessary data concerning ammunition type. The device also requires the ammunition to be located in a specific position, and thus cannot be used independently of the automatic loading system.
U.S. Pat. No. 5,157,486 describes a camera sensor having an array of charge-coupled device (CCD) units that are used in connection with the real-time creation of a high resolution silhouette image of an object on a moving conveyor. The sensor is used in relation to automatic inspection or assembly of objects. The objects pass between a camera sensor and a light source after which they move downstream to a conventional detector and diverter which enables reorientation and/or rejection of improperly oriented or sized articles. The sensor is not meant for use in combination with a weapon firing system and is thus not adapted to this purpose.
SUMMARY OF THE INVENTION
The object of the present invention is therefore to avoid the drawbacks mentioned in connection with the purely manual feeding in of the ammunition type, as well as the flaws and defects of the system according to the above-mentioned U.S. patent. Further objects of the invention are to simplify the loader's tasks and reduce the time taken to prepare the gun for firing. Provided the gunner carries out his job correctly, in all probability the target will thereby always be hit.
The above-mentioned advantages and objects are achieved with a method and a system which are characterized by features which are presented in the claims. Further features and advantages are presented in the attached dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in more detail in the form of an embodiment with reference to the attached figures, in which:
FIG. 1 illustrates a known control panel for manual feeding in of ammunition type,
FIG. 2 illustrates silhouettes of some ammunition types currently in use,
FIG. 3 is a principle drawing of a first embodiment of the invention,
FIG. 4 is a principle drawing of a second embodiment of the invention,
FIG. 5 is a principle drawing of a further development of the invention,
FIG. 6 illustrates the invention mounted inside the turret of an armoured vehicle, and
FIG. 7 illustrates the invention mounted inside the turret of an armoured vehicle viewed from another angle.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 the reference numeral 1 indicates the keys between which the loader must choose in order to specify the correct ammunition type, while reference numeral 20 designates the control panel which the loader has to operate before firing shots.
FIG. 3 illustrates a linear sensor 31 for optical reading of the ammunition's silhouettes. The sensor is placed in the roof in the vicinity of the gun's breech block and is thereby not dependent on the ammunition being placed in a specific position. It is sufficient to pass the ammunition through a zone which extends over a relatively large area. It can also be envisaged that the ammunition is stationary while the sensor(s) are moved in relation to the ammunition, or that by means of, e.g., optical systems with movable mirrors or lenses, an apparent movement is created between ammunition and sensor.
The sensor may be of different types, one type being a sensor which performs a number of one-dimensional readings of the ammunition's contour (curtain sensor). When the readings are assembled a two-dimensional image of the contour will be obtained. Another type of sensor which can be employed is a video camera or, e.g., a CCD chip which takes one or more two-dimensional images of the ammunition. The use of such sensors enables the entire system to be stationary, with no relative movement being required between sensor and ammunition. In practice, more than one image will be employed to enable noise to be removed from the images by comparing several images taken at almost the same time. By means of devices in the microprocessor 33 the two-dimensional image(s) are analysed or the series of one-dimensional images from the first sensor type. The analysis determines the ammunition's silhouette, and on this basis it can be established what kind of ammunition is recorded by the sensor(s). Identification systems of this kind work rapidly and with great reliability. The ammunition type can thereby be determined with a high degree of accuracy by the microprocessor 33, despite interference in the form of, e.g., smoke or empty shell cases.
In connection with the sensor, the system can include an infrared radiation source 32. This source emits infrared radiation at least within the zone in which the sensor(s) perform the measurement(s). The infrared radiation source can either be mounted in the vicinity of the sensor 31 (not shown) or directly incorporated with the sensor 31 as illustrated in FIGS. 3 and 4.
The sensor 31 possibly with the infrared radiation source 32 together form a read unit 30, which together with the microprocessor 33 constitute an identification device. The reference numeral 20 designates the control panel from FIG. 1, while the reference numeral 21 designates the firing computer.
In FIG. 4 the microprocessor 33 is incorporated with the sensor 31 and possibly the infrared radiation source 32 to form a complete identification device 40. The identification device according to one of the FIGS. 3 or 4 reduces the fault rate to 0.1%.
The signals from the microprocessor 33 are identical to the signals which are generated when the loader presses the correct key 1 on the control panel 20 in the known system for manual determination of ammunition type. By means of the present invention the possibility of error is avoided in connection with a manual specification of ammunition type. The firing computer 21 will thereby receive the correct ballistic data for calculation of the firing parameters when the identification device according to the invention is employed.
Between the control panel 20 and the firing computer 21 a selector switch 22 can be mounted for selecting between AUTOMATIC and MANUAL feeding of ammunition type. Even though the switch is positioned in AUTOMATIC mode, the functions which are not concerned with feeding of ammunition type will be connected to the firing computer. In a second variant (not shown in the figures) the selector switch can be built into the control panel, in which case the sensor(s) will be connected to this panel via the microprocessor which performs the actual analysis/identification of the ammunition and via the built-in selector switch.
In the embodiment according to FIG. 5 the read unit 30 together with the microprocessor 33, or the identification device 40, are extended with an additional optical sensor 41, e.g. of the CCD type. This additional sensor is preferably equipped with its own microprocessor for processing the image from the actual sensor. The assembly is generally designated by reference numeral 50. This variant further reduces the fault rate in identification of ammunition type.
FIGS. 6 and 7 illustrate the system mounted in the turret of an armoured vehicle. Reference numeral 61 designates one of the devices 30, 40 or 50 together with the cable to the control panel. The reference numerals 20 and 21 are the same as before, referring to the control panel and firing computer respectively.
It is possible to connect a display panel to the identification system. e.g. if a firing computer is not used. When the identification system has identified the ammunition type, data concerning the ammunition type are employed to obtain ballistic data from a memory dedicated thereto. This memory may either be of a non-volatile or a volatile type.
The optical sensor(s) may be of other types than that specified above, e.g. the use may be envisaged of laser systems instead of the sensor types indicated. Other optical sensors may also be used, and as such lie within the scope of the invention. Many possibilities exist, the most important according to this invention being that it is not necessary to provide the ammunition with a special marking, e.g. in the form of bar codes, magnetic or electronic tags, etc.
It is also possible to incorporate several functions together with this system, e.g. the gun can be provided with an automatic safety device. This may be implemented, e.g. in such a manner that the system secures the gun for a predetermined period after the ammunition type has been established.
A special application of the system according to the invention is for automatically correcting the firing data for the tube wear resulting from the firing of a shot with a special ammunition type. Tube wear from the use of a specific ammunition type (HEAT-T M456 A1) for armoured vehicles is illustrated in table 1, which indicates the chances in tube diameter and muzzle velocity for a 105 mm gun, with consequent adjustment of the elevation for a given firing distance.
Other ammunition types give other wear values. When firing it will be necessary to correct the firing data for an existing tube wear which will be determined by the number of previously fired shots and ammunition types employed. When the ammunition type is recorded with the system according to the present invention and the shot fired, the tube wear for this shot can thereby be immediately specified and the firing data corrected for the next shot. When a firing computer is used the wear compensation can be performed entirely automatically in a particularly expedient fashion. This has obvious advantages when different ammunition types are used in turn. The standard conditions for wear correction for different ammunition types can then be stored in the firing computer's memory or in a memory connected with the microprocessor.
TABLE 1______________________________________HEAT-T M456 A11.6 NON-STANDARD CONDITIONSCHANCE OF ELEVATION ANGLE ANDDEPARTURE SPEED AS A RESULT OF TUBE WEARNo. ofstandard Tube %shells dia. change Change of elevation angleleft mm V.sub.0 of V.sub.0 1000 m 1500 m 2000 m 2500 m______________________________________186 104,496 1180 +0,511 -0,042 -0,070 -0,106 -0,152171 104,750 1177 +0,256 -0,021 -0,035 -0,053 -0,076155 105,004 1174 0 4,322 7,137 10,557 14,778139 105,258 1171 -0,256 +0,024 +0,041 +0,062 +0,070124 105,512 1168 -0,511 +0,048 +0,081 +0,124 +0,180109 105,766 1165 -0,767 +0,072 +0,122 +0,186 +0,21793 106,020 1162 -1,022 +0,096 +0,162 +0,247 +0,36178 106,274 1159 -1,278 +0,121 +0,203 +0,309 +0,45162 106,528 1156 -1,533 +0,145 +0,244 +0,371 +0,54147 106,782 1153 -1,789 +0,169 +0,284 +0,433 +0,63231 107,036 1150 -2,044 +0,193 +0,325 +0,495 +0,72116 107,290 1147 -2,300 +0,217 +0,366 +0,557 +0,8120 107,544 1144 -2,555 +0,241 +0,406 +0,618 +0,902______________________________________ | A method and a system for automatic identification of ammunition type simultaneously with the performance of loading is based on optical reading of the ammunition's silhouette, and emits a signal concerning ammunition type to a computer for calculation of parameters for firing of the ammunition or to a display panel which indicates the ballistic data for the ammunition. The system is specially, but not exclusively, intended for use in armored vehicles. The system may include a selector switch for selecting between AUTOMATIC and MANUAL modes. The method and the system may also be employed for automatic correction of firing data as a result of wear caused by the use of different ammunition types. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention claims priority of U.S. Provisional Patent Application Ser. No. 61/250,320 filed Oct. 9, 2009, titled ADAPTIVE DYNAMIC RANGE ENHANCEMENT OF AUDIO RECORDINGS, to inventors Walsh et al.; and U.S. Provisional Patent Application Ser. No. 61/381,860 filed Sep. 10, 2010, titled ADAPTIVE DYNAMIC RANGE ENHANCEMENT, to inventors Walsh et al. U.S. Provisional Patent Application Ser. Nos. 61/217,562 and 61/381,860 are hereby incorporated herein by reference.
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not Applicable
BACKGROUND
[0003] 1. Technical Field
[0004] The present invention generally relates to audio signal processing, more particularly, to enhancing audio streams and recordings by restoring or accentuating their dynamic range.
[0005] 2. Description of the Related Art
[0006] Following the adage that ‘louder is better’, it has become common practice in the recording industry to master and release recordings with higher levels of loudness. With the advent of digital media formats such as CDs, music was encoded with a maximum peak level defined by the number of bits that can be used to represent the encoded signal. Once the maximum amplitude of a CD is reached, the perception of loudness can be increased still further through signal processing techniques such as multiband dynamic range compression, peak limiting and equalization. Using such digital master tools, sound engineers can maximize the average signal level by compressing transient peaks (such as drum hits) and increasing the gain of the resulting signal. Extreme uses of dynamic range compression can introduce clipping and other audible distortion to the waveform of the recording. Modern albums that use such extreme dynamic range compression therefore sacrifice quality of musical reproduction to loudness. The practice of increasing music releases' loudness to match competing releases can have two effects. Since there is a maximum loudness level available to recording (as opposed to playback, in which the loudness is limited by the playback speakers and amplifiers), boosting the overall loudness of a song or track eventually creates a piece that is maximally and uniformly loud from beginning to end. This creates music with a small dynamic range (i.e., little difference between loud and quiet sections), oftentimes such an effect is viewed as fatiguing and void of the artist's creative expression.
[0007] The other possible effect is distortion. In the digital realm, this is usually referred to as clipping. Digital media cannot output signals higher than the digital full scale, so whenever the peak of a signal is pushed past this point, it results in the wave form becoming clipped. When this occurs, it can sometimes produce an audible click. However, certain sounds like drum hits will reach their peak for only a very short time, and if that peak is much louder than the rest of the signal, this click will not be heard. In many cases, the peaks of drum hits are clipped but this is not detected by the casual listener.
[0008] FIGS. 1 a and 1 b provide a visual representation of deleterious mastering techniques. The audio recording waveforms depicted in FIGS. 1 a and 1 b represent an originally mastered track and a version of the same track that has been mastered using different techniques. FIG. 1 a represents the original recording, the presence of numerous peaks indicates a high dynamic range that is representative of the kinds of dynamics present in the original performance. This recording provides for a vibrant listening experience as certain percussive notes, such as drum hits, will sound punchy and clear. In contrast, the recording depicted in FIG. 1 b is remastered for a louder commercial CD release. Most of the peaks present in the original recording are compressed or even clipped, and the dynamic range of the recording has been compromised as a result. This increasingly aggressive use of dynamic range compression at the mastering stage of commercial music has spawned much backlash from consumers, producers and artists.
[0009] Approaches discussed in the audio industry for addressing this issue concentrate on questioning the mastering techniques that are at the origin of the issue. One such example is described in Bob Katz. Mastering Audio, Second Edition: The Art and the Science. Katz describes how recordings can be mastered for loudness without distorting the final result using calibrated monitoring of the processing signal and using more moderate compression parameters. While most mastering engineers would concur with Katz's approach is often superseded by demands of the studio management. Even if more conservative mastering techniques do become the new norm, it does not resolve the problem for the body of existing recordings already mastered and distributed to end-users.
[0010] Existing processing techniques for modifying the dynamics of an audio recording are known in the art. One such process is loudness leveling where differences between the perceived loudness of audio materials, which have been subjected to varying degrees of dynamic range compression, are normalized to some predetermined level. However, these approaches are used to normalize the average loudness of consecutive tracks played from various sources and do not make any attempt to restore the dynamic range of overly dynamic range compressed content. As a result, compressed media can sound even more devoid of dynamic expression when played at lower prescribed listening levels.
[0011] Another known technique is applying an upward expander as described in U.S. Pat. No. 3,978,423 issued to Bench, titled Dynamic Expander. An upward expander, applies a time-varying gain to the audio signal according to a fixed ‘expansion curve’ whereby the output signal level is greater than the input level above a selected threshold. As a result, the amplitude of the louder portions of the source signal is increased. However, this can result in originally dynamic soundtracks having overemphasized transients in the output signal.
[0012] Another known technique is dynamic spectral equalization, where lower and higher frequency bands are boosted when transients are detected. As a result, a more dynamic output is yielded. Dynamic spectral equalization is described in X Rodet, F Jaillet, Detection and Modeling of Fast Attack Transients (2001), Proceedings of the International Computer Music Conference; U.S. Pat. No. 7,353,169 issued to Goodwin et al, titled Transient Detection and Modification in Audio Signals; and U.S. patent application Ser. No. 11/744,465 issued to Avendano et. al., titled Method for Enhancing Audio Signals. Unlike the previous approaches, these dynamic enhancement techniques exclusively affect signal transients. However, it affects all signal transients, even those that already exhibit high dynamics. Dynamic spectral equalization generally applies processing to all audio signal content, whether or not it is needed. This can result in an overly dynamic processed output for certain types of audio content
[0013] U.S. Pat. No. 6,453,282, issued to Hilpert et al. outlines a method of transience detection in the discrete-time audio domain. Such time-domain methods are less reliable when analyzing heavily dynamic range compressed material as changes in energy due to transients becoming less apparent when looking at the signal as a whole. This leads to the misclassification of transient signals and results in yielding false positives.
[0014] In view of the ever increasing interest to improve the rendering of audio recordings, there is a need in the art for improved audio processing.
BRIEF SUMMARY
[0015] In accordance with the present invention, there are provided methods and an apparatus for conditioning an audio signal. The present invention provides a compelling enhancement to the dynamic range of audio signals, particularly for audio signals that have been subjected to deleterious mastering techniques.
[0016] According to one aspect of the present invention there is included a method for conditioning an audio signal having the steps of: receiving at least one audio signal, each audio signal having at least one channel, each channel being segmented into a plurality of frames over a series of time; calculating at least one measure of dynamic excursion of the audio signal for a plurality of successive segments of time; filtering the audio signal into a plurality of subbands, each frame being represented by at least one subband; deriving a dynamic gain factor from the successive segments of time; analyzing at least one subband of the frame to determine if a transient exists in the frame; and applying the dynamic gain factor to each frame having a transient.
[0017] The measure of dynamic excursion may be represented by the crest factor for a segment of time. A crest factor for each successive segment of time may be calculated by taking ratios of functions of peak signal magnitudes to functions of average signal magnitudes of the audio signal within the frame. The method may further include the step of calculating a subband relative energy function for at least one subband.
[0018] An overall subband transient energy may be calculated for each frame by comparing the subband transient energy in each subband of the frame, or potion of that frame, to a relative energy threshold value, and summing the number of subbands that pass that relative energy threshold value. A transient may be present in a frame where the number of subbands passing the relative energy threshold is greater than a predetermined fraction of the total subbands under analysis for that frame. For example, a transient may be present in a frame where the number of subbands passing the relative energy threshold is greater than a quarter of the total subbands under analysis for that frame.
[0019] The method continues by calculating a dynamic gain weighting factor based on the number of subbands passing the threshold for the total number of subbands under analysis. The dynamic gain factors are weighted for each frame according to the weighting factor. The previous dynamic gain for the frame may be reduced to a value of 1 using an exponential decay curve if no transients are detected for the frame. Before applying final dynamic gain to the input signal, a check for tone-like audio may be made to avoid audible modulation of strong tones present in the input signal. If a strong tone is detected within a subband, no additional gain is applied to that subband for that frame period and the dynamic gain for that subband continues to decay based on dynamic gain values of previous frames.
[0020] According to another aspect of the present invention, an audio signal processing apparatus is provided. The audio signal processing apparatus comprising: a receiving component for receiving at least one audio signal, each audio signal having at least one channel, each channel being segmented into a plurality of frames over a series of time; a calculating component for calculating at least one measure of dynamic excursion of the audio signal for a plurality of successive segments of time; a filtering component for filtering the audio signal into a plurality of subbands, each frame being represented by at least one subband; a deriving component for deriving a dynamic gain from the measure of dynamic excursion and analyzing at least one subband of the frame to determine if a transient exists in the frame; and applying the dynamic gain to each frame having the transient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which:
[0022] FIG. 1 a is a perspective view of a waveform of an original audio recording;
[0023] FIG. 1 b is a perspective view of a waveform of a remastered audio recording where the dynamic range has been overly compressed;
[0024] FIG. 2 is a schematic view of a listening environment employing adaptive dynamic enhancement for playback over multi channel loudspeakers or headphones in accordance with an embodiment of the present invention;
[0025] FIG. 3 is a flowchart depicting an optional loudness leveling processing block preceding the adaptive dynamics enhancement processor in accordance with an embodiment of the present invention;
[0026] FIG. 4 is a flowchart depicting the steps taken during adaptive dynamic enhancement processing to detect a transient and accordingly apply a gain in accordance with one embodiment of the present invention;
[0027] FIG. 5 is a flowchart depicting the steps taken during adaptive dynamic enhancement processing to detect a transient, assess the transient against a known threshold, and accordingly apply an adaptive EQ curve in accordance with one embodiment of the present invention
DETAILED DESCRIPTION
[0028] The detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiment of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the functions and the sequence of steps for developing and operating the invention in connection with the illustrated embodiment. It is to be understood, however, that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention. It is further understood that the use of relational terms such as first and second, and the like are used solely to distinguish one from another entity without necessarily requiring or implying any actual such relationship or order between such entities.
[0029] An object of the present invention addresses deleterious recording techniques where audio recordings are mastered to be as loud as possible using aggressive applications of dynamic range compression algorithms. The dynamic excursions of transients in those recording signals are much lower than they should be. This yields a perception of a muted, dull or lifeless reproduction when listening at moderate levels.
[0030] The present invention analyzes the dynamics of audio recordings and enhances the transients that show evidence of deleterious mastering practices. The present invention is designed using smart/adaptive processing driven by analysis of the loudness and dynamics properties of the source audio recording signal. Modifying the dynamics of the original audio recording signal is avoided unless necessary. However, the default amount of additive dynamics processing can also be adjusted by the user such that the dynamics of any recording can be exaggerated for an even sharper or ‘more punchy’ sound, or reduced for a more subtle enhancement. The invention could be used to enhance transient dynamics in any music, movie or gaming soundtrack derived from any media source and in any listening environment.
[0031] Now referring to FIG. 2 , a schematic diagram depicting the implementation of multiple embodiments is provided. FIG. 2 depicts an audio listening environment for playback of dynamically enhanced audio recordings over loudspeakers or headphones. The audio listening environment includes at least one consumer electronics device 10 , such as a DVD or BD player, TV tuner, CD player, handheld player, Internet audio/video device, a gaming console, or the like. The consumer electronic device 10 provides a source audio recording that is dynamically enhanced to compensate for any deleterious mastering techniques.
[0032] In the present embodiment, the consumer electronic device 10 is connected to an audio reproduction system 12 . The audio reproduction system 12 processes the audio recording through adaptive dynamic enhancement processing (ADE), which dynamically enhances the audio recording. In an alternative embodiment, a standalone consumer electronic device 10 may enhance the audio recording through ADE processing.
[0033] The audio reproduction system unit 12 includes a Central Processing Unit (CPU), which may represent one or more conventional types of such processors, such as an IBM PowerPC, Intel Pentium (x86) processors, and so forth. A Random Access Memory (RAM) temporarily stores results of the data processing operations performed by the CPU, and is interconnected thereto typically via a dedicated memory channel. The audio reproduction system 12 may also include permanent storage devices such as a hard drive, which are also in communication with the CPU over an i/o bus. Other types of storage devices such as tape drives, optical disk drives may also be connected. A graphics card is also connected to the CPU via a video bus, and transmits signals representative of display data to the display monitor. External peripheral data input devices, such as a keyboard or a mouse, may be connected to the audio reproduction system over a USB port. A USB controller translates data and instructions to and from the CPU for external peripherals connected to the USB port. Additional devices such as printers, microphones, speakers, and the like may be connected to the audio reproduction system 12 .
[0034] The audio reproduction system 12 may utilize an operating system having a graphical user interface (GUI), such as WINDOWS from Microsoft Corporation of Redmond, Wash., MAC OS from Apple, Inc. of Cupertino, Calif., various versions of UNIX with the X-Windows windowing system, and so forth. The audio reproduction system 12 executes one or more computer programs. Generally, the operating system and the computer programs are tangibly embodied in a computer-readable medium, e.g. one or more of the fixed and/or removable data storage devices including the hard drive. Both the operating system and the computer programs may be loaded from the aforementioned data storage devices into the RAM for execution by the CPU. The computer programs may comprise instructions which, when read and executed by the CPU, cause the same to perform the steps to execute the steps or features of the present invention.
[0035] The foregoing audio reproduction system 12 represents only one exemplary apparatus suitable for implementing aspects of the present invention. The audio reproduction system 12 may have many different configurations and architectures. Any such configuration or architecture may be readily substituted without departing from the scope of the present invention. A person having ordinary skill in the art will recognize the above described sequences are the most commonly utilized in computer-readable mediums, but there are other existing sequences that may be substituted without departing from the scope of the present invention.
[0036] Elements of one embodiment of ADE processing may be implemented by hardware, firmware, software or any combination thereof. When implemented as hardware, the ADE processing may be employed on one audio signal processor or distributed amongst various processing components. When implemented in software, the elements of an embodiment of the present invention are essentially the code segments to perform the necessary tasks. The software preferably includes the actual code to carry out the operations described in one embodiment of the invention, or code that emulates or simulates the operations. The program or code segments can be stored in a processor or machine accessible medium or transmitted by a computer data signal embodied in a carrier wave, or a signal modulated by a carrier, over a transmission medium. The “processor readable or accessible medium” or “machine readable or accessible medium” may include any medium that can store, transmit, or transfer information. Examples of the processor readable medium include an electronic circuit, a semiconductor memory device, a read only memory (ROM), a flash memory, an erasable ROM (EROM), a floppy diskette, a compact disk (CD) ROM, an optical disk, a hard disk, a fiber optic medium, a radio frequency (RF) link, etc. The computer data signal may include any signal that can propagate over a transmission medium such as electronic network channels, optical fibers, air, electromagnetic, RF links, etc. The code segments may be downloaded via computer networks such as the Internet, Intranet, etc. The machine accessible medium may be embodied in an article of manufacture. The machine accessible medium may include data that, when accessed by a machine, cause the machine to perform the operation described in the following. The term “data” here refers to any type of information that is encoded for machine-readable purposes. Therefore, it may include program, code, data, file, etc.
[0037] All or part of an embodiment of the invention may be implemented by software. The software may have several modules coupled to one another. A software module is coupled to another module to receive variables, parameters, arguments, pointers, etc. and/or to generate or pass results, updated variables, pointers, etc. A software module may also be a software driver or interface to interact with the operating system running on the platform. A software module may also be a hardware driver to configure, set up, initialize, send and receive data to and from a hardware device.
[0038] One embodiment of the invention may be described as a process which is usually depicted as a flowchart, a flow diagram, a structure diagram, or a block diagram. Although a block diagram may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed. A process may correspond to a method, a program, a procedure, etc. FIG. 2 is a schematic diagram illustrating an audio reproduction system 12 for reproduction over headphones 14 or loudspeakers 16 . The audio reproduction system 12 may receive digital or analog audio source signals from various audio or audio/video sources 10 . The audio source signal may be a mono signal, a two-channel signal (such as a music track or TV broadcast), or a multi-channel signal (such as a movie soundtrack). The audio signal may be any perceived or unperceived sound, such as a real world sound, or an engineered sound, and the like.
[0039] The audio reproduction system 12 can include analog-to-digital converters for connecting analog audio sources, or digital audio input interfaces. It may include a digital signal processor for processing the audio signals, as well as digital-to-analog converters and signal amplifiers for converting the processed output signals to electrical signals sent to the transducers (headphones 14 or loudspeakers 16 ). The audio reproduction system 12 may be a home theater receiver or an automotive audio system dedicated to the selection, processing and routing of audio and/or video signals. Alternatively, the audio reproduction system 12 and one or several of the audio signal sources may be incorporated together in a consumer electronics device 10 , such as a portable media player, a TV set or a laptop computer. The loudspeakers 16 may also be incorporated in the same appliance, as in the case of a TV set or a laptop computer.
[0040] FIG. 3 is a high level flow chart depicting the ADE processing environment. The flow chart initiates at step 300 by receiving an input signal. The input signal is an digital audio signal. In the present embodiment, at step 310 , the input signal is processed by a loudness leveling algorithm, whereby the gain of the incoming input signal is adapted over time such that it has a substantially constant average loudness level (say, −20 dB relative to 0 dB full scale). The loudness level algorithm is an optional feature and is not required for implementing ADE processing. Subsequently, at 320 , if there is an upstream gain normalization algorithm, ADE processing may factor the reference gain level into available headroom that is required to extend the gain of the incoming signal without causing audible artifacts that may result from signal waveform clipping. This communication is depicted by the dotted arrow. ADE headroom requirements may also factor the input master gain and the gain of the input signal content. The amount of dynamics enhancement applied can be scaled using the user parameter described by DYNAMICS ENHANCEMENT LEVEL. The output limiter is used to ensure that no output saturation takes place as a result of applying the required dynamic EQ to the input signal.
[0041] Now referring to FIG. 4 , a flowchart depicting one embodiment of ADE processing is depicted. ADE processing is initiated at step 400 by receiving an input signal representing an audio recording. The input signal is a digital audio signal of at least one channel. The input signal represents a tangible physical phenomenon, specifically a sound, which has been converted into an electronic signal, converted to a digital format by Analog/Digital conversion, and suitably pre-processed. Typically, analog filtering, digital filtering, and other pre-processes would be applied to minimize aliasing, saturation, or other signal processing errors downstream, as is known in the art. The audio signal may be represented by a conventional linear method such as PCM coding. At step 410 , the input signal is filtered by a multi-tap, multi-band, analysis filter bank, which may suitably be a bank of complementary quadrature minor filters. Alternatively pseudo quadrature mirror filters (PQMF) such as polyphase filter banks could be used. The filter bank produces a plurality of subband signal outputs. In the present embodiment, 64 of such subband outputs are employed. However, a person skilled in the art will readily recognize that the input signal may be filtered into any number of subbands. As part of the filtering function, filter bank should preferably also critically decimate the subband signals in each subband, specifically decimating each subband signal to a lesser number of samples/second, just sufficient to fully represent the signal in each subband (“critical sampling”). This subband sampling may also mimic the physiology of human hearing.
[0042] Subsequent to filtering, the subbands are analyzed for transient detection at step 420 . It is contemplated that not all subbands are analyzed for transients, as it may be known that certain frequencies have a lower likelihood of having transients. In the present embodiment, transients are detected using a transient detection algorithm that calculates a weighted sum of energies across frequency bands. Since the energy of the signal usually dominates the lower frequencies, the additional weighting is used to emphasize the energy of the signal where transients are more noticeable. This decreases the possibility of ‘false positives’ during the identification of transients:
[0000]
TE
HF
(
m
,
c
)
=
∑
k
=
0
N
-
1
w
(
k
)
G
(
k
,
m
,
c
)
2
,
(
1
)
[0043] where TE HF (m,c) is the instantaneous, high-frequency weighted, transient energy, k is the frequency band index, m is the analysis frame index, c represents the channel index, w(k) corresponds to the k-th frequency weighting filter coefficient and. |G(k,m,c)| represents the absolute gain of the k-th band of the m-th analysis frame of the c-th channel. A person skilled in the art will understand that various transient detection algorithms may be applied in accordance to the present invention and the above the example is provided by way of example and should not be construed as limiting the scope of the invention.
[0044] The instantaneous transient energy function is compared to a time average of previous transient energies. This comparison will indicate a likely transient event wherein the instantaneous transient energy should be much greater than the average transient energy. The average transience energy, TE av , may be calculated by applying a leaky integrator filter in each frequency band:
[0000] TE av ( m,c )(1−α TE )TE av ( m− 1, c )+α TE TE HF ( m,c ), (2)
[0045] where α TE corresponds to the transience energy damping factor, m represents the frame index and c represents the channel index
[0046] A transient onset is triggered if
[0000]
TE
HF
(
m
,
c
)
TE
av
(
m
,
c
)
>
G
TRANS
,
[0000] where G TRANS corresponds to some predetermined transience threshold value. Typically, values of G TRANS between 2 and 3 yield good results, but threshold values can also change depending on the source material. Subsequently, at step 440 , a multiband crest factor value, CF(k,m,c), is calculated by taking the ratio of the peak signal levels to a time average of previous signal levels within each of the 64 analysis bands.
[0000]
CF
(
k
,
m
,
c
)
=
G
peak
(
k
,
m
,
c
)
G
av
(
k
,
m
,
c
)
(
3
)
[0047] Both the peak signal level and the average signal level are derived using leaky integrators having different attack and release time constants. Alternative methods of calculating average signal levels include averaging across several ‘frames’ of past frequency subbands stored in system memory. The peak and average gain computations in this embodiment use leaky integrator filters.
[0000] G peak ( k,m,c )=(1−α peak — att ) G peak ( k,m− 1, c )+α peak — att G ( k,m,c )
[0000] if G ( k,m,c )> G peak ( k,m− 1, c ) (4)
[0000] G peak ( k,m,c )=(1−α peak — rel ) G peak ( k,m− 1, c )+α peak — rel G ( k,m,c )
[0000] if G ( k,m,c )≦ G peak ( k,m− 1, c ) (5)
[0000] G av ( k,m,c )=(1−α av ) G av ( k,m− 1, c )+α av G ( k,m,c ) (6)
[0048] The derived crest factor is based on a ratio of gains. As a result, the derived crest factor is independent of the level of the input signal. Thus, the results are the same regardless of the master gain of the system or the recording level of the original recording. Looking at eq. (3), distinctive transients, such as percussion hits, should have a higher crest factor value than more steady state or tone-like signals. If a signal contains a transient onset that exhibits contrary crest factor values, this is a strong indicator of post-recording dynamic range compression or limiting at that frequency band. In this case, it is likely that the original signal could benefit from a short-time gain boost to yield an expected crest factor value, where short-time refers to onset and decay time on the order of the onset and decay time of the of the detected transient.
[0049] As a result, ADE processing assesses the crest factor whenever a transient onset is detected. At step 460 , the crest factor is assessed and if it is lower than a target crest factor threshold (determined through a combination of algorithm tuning and/or user preference), the gain in that subband is increased such that the desired crest factor value is attained. This gain may be limited to remain within a prescribed or dynamically assessed headroom budget:
[0000]
G
eq
(
k
,
m
,
c
)
=
min
(
G
eq_max
,
(
1
-
α
attack
)
G
eq
(
k
,
m
-
1
,
c
)
+
α
attack
CF
target
CF
(
k
,
m
,
c
)
)
if
CF
Target
CF
(
k
,
m
,
c
)
<
1
and
TE
HF
(
m
,
c
)
>
G
TRANS
TE
av
(
m
,
c
)
(
7
)
[0050] where, G eq (k,m,c) represents the applied gain function, G eq — max represents the maximum allowable gain (usually corresponding to the allotted algorithm headroom), α attack is a gain attack damping function which may be tuned to some value close to 1 if artifacts are discovered resulting from rapid gain changes. The value of this damping function could be frequency dependent to allow gain ramping to occur at different rates for different frequency ranges. CF Target represents the target crest factor value and CF(k,m,c) represents the measured crest factor value at frequency k and frame m and channel c.
[0051] If a transient onset is not detected or if the crest factor is greater than or equal to the target crest factor value the applied dynamic EQ gain falls back towards a value of 1 using an envelope that mimics a the dynamics of a typical transient hit. The rate of gain reduction is weighted such that higher frequency gains reduce faster than lower frequency gains:
[0000] G eq ( k,m,c )=max(1,α decay ( k,m ) G eq ( k,m− 1, c )) (8)
[0000] where α decay (k.m) represents a frequency dependent decay damping factor. In the current embodiment, α decay (k.m) is represented by a 64-point function that ramps exponentially across frequency from a higher to a lower value with boundaries of 1 and 0.
[0052] At step 480 , the user parameter represented by the ‘Dynamics Enhancement Level’ (DEL) scales the target crest factor by a value between 0.0 and 1.0. A DEL value of 0.0 implies that the crest factor threshold will always be attained, and therefore no enhancements will be made on the original signal. A DEL value of 0.5 represents the default analysis threshold and represents a ‘reasonable’ crest factor expectation. With this value, signals that have been compressed are enhanced, while signals with sufficient dynamics will receive little or no dynamics enhancement. A DEL value of 1.0 represents more than a ‘reasonable’ crest factor expectation, such that the dynamics of most transients will be enhanced whether or not they need it.
[0053] The output is derived by multiplying the subband input signal components with a time-varying EQ curve that is derived from the enhancement gains. These gains are smoothed across frequency to avoid artifacts. The EQ curve is applied to the original complex input signal data and the resulting complex band coefficients are then recombined and transformed to a time domain output sample block using a 64-band synthesis bank or equivalent frequency-to-time domain filter. Finally, the time-domain output of the synthesis filter band is passed through a soft limiter (or equivalent) to counteract any occasional level overshoots that may have been caused by signal level increases that were beyond the available headroom.
[0054] This input/output process is repeated for each analysis frame. The gain of the EQ curve dynamically changes according to the analysis of each frame. In the embodiment described above, the derived gain curve was applied to the original signal by multiplication in the frequency domain followed by an output synthesis that is complementary to the input synthesis block. In other embodiments, the analysis and synthesis methods may differ. For example, the analysis could take place in the frequency domain, as described above, and once the desired gain curve has been calculated, a filter representing that desired frequency response could be implemented in the time domain using FIR and/or IIR filters. The coefficients of the time domain filters would change according to the analysis of each input data frame. Alternatively, the analysis of crest factors and transient onset detection could also take place in the time domain in its entirety.
[0055] The analysis and synthesis described above uses evenly spaced frequency bands. It is preferred to perform the analysis over logarithmically spaced bands that better match the psychoacoustics of human hearing.
[0056] Now referring to FIG. 5 , a flowchart depicting a preferred embodiment of ADE processing is presented. The flow chart initiates, at step 500 , by converting input signals into a complex frequency domain representation using 64-band oversampled polyphase analysis filter banks. Other types of filter banks could be used. A different number of filter banks could also be used. In the implementation described here, the analysis filter bank extracts a block of 64 frequency domain samples for each block of 64 time domain input samples, to form subband audio signals.
[0057] At step 510 , a frequency independent per-frame crest factor is derived for each channel, in order to assess the amount of dynamics present in the input signal.
[0058] Where H sum (m,c) is defined as the sum of k frequency band magnitudes for the mth frame of the cth channel of input data:
[0000] H sum ( m,c )=Σ H ( k,m,c )
[0059] A peak sum function is defined as
[0000] H sum — pk ( m,c )= H sum ( m,c )) if H sum ( m,c )> H sum — pk ( m− 1, c )
[0000] otherwise,
[0000] H sum — pk ( m )=(1−α pk — rel ) H sum — pk ( m− 1)+α pk — rel H sum ( m )
[0060] The average sum function is defined by the leaky integrator function:
[0000] H sum — av ( m,c )=(1−α avg ) H sum — av ( m− 1, c )+α avg H sum ( m,c )
[0061] where α pk — rel represents the peak release coefficient and α avg represents the average smoothing coefficient.
[0062] The per-frame crest factor is defined as the ratio of the peak signal magnitude to average signal magnitude,
[0000]
CF
(
m
,
c
)
=
H
sum_pk
(
m
,
c
)
H
sum_av
(
m
,
c
)
[0063] where CF(m) represents the crest factor of the m th frame of the c th channel of input data. It is contemplated that the crest factor may be described in terms of energy summation.
[0000] H sum ( m,c )=Σ| H ( k,m,c )| 2
[0064] The per-frame crest factor indicates the amount of dynamic range present in the input signal. This crest factor should be greater than or equal to some expected target value when a transient is detected. If the per-frame crest factor is too low in the presence of a transient, a short-term gain is applied to the input signal frame to increase the measured crest factor to a more-expected value, where short-time here refers to onset and decay time on the order of the onset and decay time of the of the detected transient.
[0065] At step 520 , a per-frame dynamic gain, G DYN (m,c) is derived by taking the ratio of the a prescribed target crest factor, CF T and the measured crest factor CF(m,c) represents the amount of gain required to attain the desired level of dynamic excursion.
[0000]
G
DYN
(
m
,
c
)
=
CF
T
CF
(
m
,
c
)
[0066] The value of CF T is assumed to represent a reasonable crest factor for dynamic material, 14 dB for example. This prescribed target crest factor could also be modified by a user controllable gain called the Dynamic Enhancement Level (DEL) thereby indirectly affecting the amount of enhancement applied.
[0000]
G
DYN
(
m
,
c
)
=
[
DEL
*
CF
T
]
CF
(
m
,
c
)
[0000] If the target crest factor is greater than the measured crest factor, G DYN (m,c) will be less than 1. If this gain value were allowed, it would ultimately lead to a decrease in the level of transient events in the input. However, in the present embodiment G DYN (m,c) is limited to be greater or equal to 1.
[0000]
G
DYN
(
m
,
c
)
=
max
(
1
,
[
DEL
*
CF
T
]
Cf
(
m
,
c
)
)
[0000] The G DYN (m,c) is not applied to the input signal at this stage. But rather, it is only applied if two other conditions are met:
1. A transient has been detected for the current frame; or 2. The subbands to which the gain is applied do not have any strong tonal content.
[0069] At step 540 , transients in the current frame are detected. The subband signals are analyzed to detect transients using a transient detection algorithm that calculates a per subband relative energy function. The value of this function will increase sharply when a large increase in energy is detected within a subband. The presence of more subbands indicates a simultaneous increase, which further indicates a higher likelihood that a transient has been detected within a given frame.
[0000] The relative energy function may be defined as:
[0000]
RE
(
k
,
m
,
c
)
=
E
inst
(
k
,
m
,
c
)
E
av
(
k
,
m
,
c
)
(
1
)
[0070] where E inst (k,m,c) represents the energy measured at the k th subband of the m th frame of the c th channel and E av (k,m,c) represents the averaged energy measured at the k th subband of the m th frame of the c th channel. The per-subband averaging is based on a leaky integration function:
[0000] E av ( k,m,c )=(1−ε av ) E av ( k,m− 1, c )+ε av E inst ( k,m,c )
[0071] For each subband relative energy function, the current value is compared to some relative energy threshold value, RE TRESH . If the relative energy function threshold is exceeded in a subband, that subband is tagged as having an energy increase that is indicative of a transient. An overall per-frame transient energy function is then calculated by summing the number of subbands that pass the relative energy threshold:
[0000] TE( m,c )=Σ(RE( k,m,c )>RE TRESH )
[0072] Here, TE(m,c) is an integer value between 0 and K where K represent that total number of subbands used for analysis. Note that K can be less than the total number of bands in the frame. For example, it may be more desirable to focus transience detection on subbands bands in which significant energy has been detected.
[0073] A significant proportion of subbands surpassing the relative energy threshold is indicative of a broadband increase of energy that is representative of a transient. However, it is difficult to correlate an exact number of subbands with positive results to specifically define a transient. In some circumstances, the average signal level may be so high that the relative energy threshold may remain low in many bands. While the required number of subbands with positive results to account for this may be lowered, this may lead to a ‘false-positive’ transient detection. Therefore, the per-frame transient energy function is thresholded to derive an estimate of the likelihood of a transient. Further, a series of gain weighting functions are calculated that are proportional to the number of subbands in which RE TRESH is exceeded. For example,
[0000] W T ( m,c )=1 if TE( m,c )> K/ 2
[0000] W T ( m,c )=0.75 if TE( m,c )> K/ 3
[0000] W T ( m,c )=0.5 if TE( m,c )>K/4;
[0074] where K represents the total number of subbands under analysis.
[0075] Otherwise,
[0000] W T ( m,c )=0
[0076] Other values could be used for the positive subband thresholds and the associated weighting gains. At step 550 , it is determined that any value of W T (m,c)>0 on either input channel represents a transient onset. The dynamic gain is then modified by the weighting factor:
[0000] G DYN — MOD ( m,c )=max(1, G DYN ( m,c )* W T ( m,c ))
[0077] The boundary check is applied to ensure a gain less than 1 is not applied. This gain can them be applied to all subbands of the current data frame. However, this may not be desired in subbands that have significant tone-like components as a sudden increase in gain in these bands may result in audible signal modulation. To avoid this scenario, each subband is analyzed for the presence of strong tones. By their nature, tone-like components have relatively low peak-to-average ratios (or subband crest factors). Therefore, there are no additional gains applied to subbands having measured crest-factors that are below a so called tonality threshold and they continue to decay based on their original decay trajectory.
[0078] At step 530 , a per subband crest factor value is calculated by taking the ratio of the peak gain levels to a time averaged gain within each of the analysis bands.
[0000]
CF
(
k
,
m
,
c
)
=
G
peak
(
k
,
m
,
c
)
G
av
(
k
,
m
,
c
)
[0079] Both the peak and the average filters are implemented using leaky integrators.
[0000] G peak ( k,m,c )= G ( k,m,c ) if G ( k,m,c )>G peak ( k,m− 1, c )
[0080] where G(k,m,c) represents the magnitude of the k th subband of the m th frame of the c th channel. Otherwise,
[0000] G peak ( k,m,c )=(1=β peak — rel ) G peak ( k,m− 1, c )+β peak — rel G ( k,m,c ))
[0000] G av ( k,m,c )=(1−β av ) G av ( k,m− 1, c )+β av G ( k,m,c ))
[0081] where β peak — rel represents the per-subband peak release function and β av represents the average smoothing function.
[0082] In frames where a transient onset is detected, the per subband crest factor is compared to a predefined threshold, γ TONE , which determines if a tone like component is present in that subband. If the subband crest factor is below this threshold, we assume a tone-like component is detected and no gains are applied to that subband for that frame. Various measures of tonality may be used, such as a coefficient of tonality as described in J. Johnston, “ Transform coding of audio signals using perceptual noise criteria,” IEEE J Sel. Areas in Comm., vol. 6, no. 2, pp. 314-323, February 1998. The final per-subband dynamic gains, described as EQ DYN (k,m,c) are instantly updated to a value of:
[0000] EQ DYN ( k,m,c )= G DYN — MOD ( m,c ) if CF ( k,m,c )> γTONE
[0083] At step 560 , it is determined that if no transients are detected or if a tone-like component is detected in a subband, the relevant subband values of EQ DYN (k,m,c) decay towards a value of 1 (no processing) using a frequency dependent exponential curve that models a typical transient decay function:
[0000] EQ DYN ( k,m,c )=max( EQ DYN ( k,m,c )*σ decay ( k ),1)
[0084] where σ δecay (k) represents a per-subband decay coefficient function that decreases with increasing frequency to mimic how lower frequency transients decay more slowly than high frequency transients. The boundary check is applied to ensure a gain less than 1 is not applied.
[0085] At step 570 , EQ DYN (k,m,c) is constrained within a limited range to avoid output saturation, as follows:
[0000]
If
EQ
DYN
(
k
,
m
,
c
)
*
X
(
k
,
m
,
c
)
>
Y
max
EQ
DYN
(
k
,
m
,
c
)
=
EQ
DYN
(
k
,
m
,
c
)
Y
max
X
(
k
,
m
,
c
)
[0086] where |X(k,m,c)| represents the magnitude of the input data for the k th bin of the m th frame of the c th channel and Y max represents the maximum allowed output value for every subband of every frame of every channel. The final version of EQ DYN (k,m,c) can be smoothed across frequency to avoid artifacts, if warranted.
[0087] At step 580 , the prescribed enhancement is applied to the appropriate input channel by multiplying the complex input coefficients in each band with EQ DYN (k,m,c).
[0000] Y ( k,m,c )= EQ DYN ( k,m,c ) X ( k,m,c )
[0000] where X(k,m,c) represents the input data for the k th bin of the m th frame of the c th channel and Y(k,m,c) represents the output data for the k th bin of the M th frame of the c th channel.
[0088] The resulting complex band coefficients are recombined and transformed to a time domain output sample block using a 64-band synthesis bank or equivalent frequency-to-time domain filter.
[0089] The input/output processes described above (steps 500 -s 580 ) are repeated for each input sample block. The gain of the EQ curve will change dynamically according to the analysis of each input signal block.
[0090] The gain of the EQ curve dynamically changes according to the analysis of each input signal frame. In the embodiment described above, the derived gain curve is applied to the original signal by multiplication in the frequency domain followed by an output synthesis that is complementary to the input synthesis block. In other embodiments, the analysis and synthesis method may be different.
[0091] The analysis and synthesis described above employs evenly spaced frequency bands. However, it is preferred to perform the analysis over logarithmically spaced bands that better match the psychoacoustics of human hearing.
[0092] The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show particulars of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice. | There are provided methods and an apparatus for conditioning an audio signal. According to one aspect of the present invention there is included a method for conditioning an audio signal having the steps of: receiving at least one audio signal, each audio signal having at least one channel, each channel being segmented into a plurality of frames over a series of time; calculating at least one measure of dynamic excursion of the audio signal for a plurality of successive segments of time; filtering the audio signal into a plurality of subbands, each frame being represented by at least one subband; deriving a dynamic gain factor from the successive segments of time; analyzing at least one subband of the frame to determine if a transient exists in the frame; and applying the dynamic gain factor to each frame having a transient. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
This is a divisional of an application filed Aug. 13, 2001 and assigned U.S. Ser. No. 09/928,827.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to forming polymeric materials and more particularly to a method and apparatus for forming distortion-free polymeric materials.
Polymeric materials are used in a wide variety of applications. Typically, polymeric materials are used to manufacture transparent panels such as windows or windshields for various applications including aircraft, automobiles, motorcycles, boats and the like. Such applications, especially those for aircraft, require an extremely clear, undistorted, transparent panel, which is resistive to scratching and impact in order to afford the pilot a clear view of the surroundings.
Traditionally, acrylic plastic is used to form such transparent panels. Acrylic plastic is noted for its excellent optical properties and weatherability, having outstanding resistance to the effects of sunlight and exposure to the elements over long periods of time. Subjected to long term exposure to the elements, acrylic plastic does not experience significant yellowing or any other significant changes in its physical properties. Acrylic plastic, however, does not have as high an impact strength as do other polymeric materials and thus, are less preferred for applications where impact strength is of importance.
Polycarbonate is a high-performance thermoplastic with the characteristics of high impact strength, optical clarity, heat resistance and dimensional stability. Polycarbonate, on the other hand, does not include the same weatherability characteristics of acrylic plastic. However, the transparent panels, whether produced using acrylic plastic or polycarbonate, include a hard protective coating to prevent scratching, abrasions or other markings that would reduce the service life of the transparent panel. Further, the hard protective coating protects the base sheet, whether acrylic plastic or polycarbonate, from UV degradation. As a result, the transparent panel is protected from any degradation, such as yellowing, abrasion distorting, and the like, even though the base sheet (e.g. polycarbonate) would otherwise degrade from such exposure. Therefore, it is desirable in the industry to use polycarbonate for producing transparent panels because of its high impact strength, while it remains protected from UV degradation and abrasion by the protective coating which is applied regardless of the material used.
Traditionally, polymeric sheets of acrylic plastic are formed using molds that include contoured upper and lower surfaces. The contoured surfaces define the desired shape of the polymeric sheet, directly contacting the entire upper and lower surfaces of the polymeric sheet. Because of the hardness of the upper and lower surfaces of an acrylic plastic sheet, it may be formed in this manner without distorting the upper and lower surfaces. However, the upper and lower surfaces of a polycarbonate sheet are not as hard and therefore, when heated, may be distorted upon contact during the forming process. For this reason, the use of traditional molds, which directly contact the upper and lower surfaces of the polymeric sheet, are not desirable for forming polycarbonate sheets. Traditional molds have increased potential for distorting the surfaces of the polycarbonate sheet, thus producing an increased number of rejected panels and driving up production costs.
Accordingly, the present invention provides an apparatus for forming a polymeric material, such as polycarbonate. The present invention enables forming of a polycarbonate sheet without distorting the key visibility areas of the sheet. The apparatus of the present invention provides a forming mold including a first half having a bottom wall and a first side wall defining a first interior space and a first edge and a second half having a top wall and a second side wall defining a second interior space and a second edge. The first and second halves come together to clamp the peripheral edge portions of a sheet of polymeric material therebetween for forming the sheet whereby the sheet is vacuum drawn into one of the first and second interior spaces. A cooling mechanism is disposed within one of the first and second interior spaces and a sensing mechanism is attached to one of the first and second halves for sensing a draw depth of the sheet within one of the first and second interior spaces. The first edge is preferably contoured for defining a final edge contour of the sheet and the second edge correspondingly contoured for facilitating engagement of the first and second halves. Further, the first edge is preferably beveled and the second edge correspondingly beveled for facilitating engagement of the first and second halves.
In a preferred embodiment, a trimming mechanism is provided for trimming a perimeter of the sheet to a desired shape. A retention mechanisms is also provided and operatively supported by one of the first and second halves for biasing the sheet into contact with one of the first and second edges of the first and second halves.
The present invention further provides an improved method for forming a sheet of polymeric material. The method of the present invention includes the steps of: heating the sheet to a first temperature, retaining a sheet between first and second mold halves of a forming mold, generating a vacuum on one side of the sheet thereby drawing the sheet into an interior space of one of the first and second mold halves, and cooling the sheet from the first temperature to a second temperature upon achieving a specified draw depth of the sheet within one of the first and second mold halves. The method preferably includes the step of detecting a draw depth of the sheet within one of the first and second mold halves for initiating the cooling. Alternatively, the heated sheet may be formed by use of blow air to exert a pressure on the other side of the sheet in lieu of the vacuum forming process or perhaps by use of a combination of both blow air and vacuum on opposite sides of the sheet.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a perspective view of a forming mold in accordance with the present invention;
FIG. 2 is a top view of the forming mold of FIG. 1 ;
FIG. 3 is a side view of a lower half of the forming mold;
FIG. 4 is a sectional view of the forming mold taken along line 4 - 4 of FIG. 2 ;
FIG. 5A is a detailed view of a retention mechanism of the forming mold;
FIG. 5B is a view of an alternative embodiment of a trimming means;
FIG. 6 is a perspective view of the lower half of the forming mold having a finished polymeric sheet resting thereon.
FIG. 7 is a perspective view of the forming mold including an alternative trimming means; and
FIG. 8 is a schematic view of an exemplary processing line for forming the polymeric material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
With reference to the Figures, there is shown a forming mold 10 including upper and lower halves 12 , 14 that come together to form a heated sheet of polymeric material 16 therebetween. The sheet 16 is preferably an optical quality polycarbonate material and is retained within a rigid frame 17 having a length and width somewhat greater than that of the upper and lower halves 12 , 14 , and that clamps about the complete peripheral edge of the sheet 16 . Edges of the upper and lower halves 12 , 14 are contoured to define a desired end form for peripheral edges of the sheet 16 . A vacuum is created within an interior space 18 of the lower half 14 for drawing the sheet 16 downward, thereby forming the sheet 16 as defined by the contoured edges of the upper and lower halves 12 , 14 . The drawing process ensues until the sheet 16 crosses a trigger point whereby the vacuum draw ceases and cooling mechanisms 20 , disposed within an interior space 22 of the upper half 12 , act to cool the sheet 16 in its desired end form. Alternatively, rather than drawing a vacuum in interior space 18 , the gas pressure in interior space 18 may be increased by supplying pressurized gas thereto to exert a forming force on sheet 16 or both a vacuum within space 18 and increased gas pressure within space 22 may be utilized to accomplish the forming operation.
In an exemplary embodiment, the forming mold 10 is configured for forming an aircraft windshield. As best seen in FIG. 2 , the perimeter of the forming mold 10 is correspondingly shaped for the particular application. It will be appreciated, however, that the forming mold 10 can be configured to form sheets 16 into various shapes and contours in accordance with the requirements of a variety of applications. The lower half 14 includes a bottom wall 24 and four sidewalls 26 , 28 , 30 , 32 defining the interior space 18 . The sidewalls 26 , 28 , 30 , 32 have upper edges 34 , 36 , 38 , 40 , respectively, and are selectively contoured along their lengths for defining the end form of the peripheral edge of sheet 16 . The upper edges 34 , 36 , 38 , 40 are preferably beveled, sloping downward toward the interior of the lower half 14 . The upper half 12 includes a top wall 42 and four sidewalls 44 , 46 , 48 , 50 defining the interior space 22 . The sidewalls 44 , 46 , 48 , 50 have lower edges 52 , 54 , 56 , 58 , respectively, and are correspondingly contoured along their lengths to engage the upper edges 34 , 36 , 38 , 40 . The lower edges 52 , 54 , 56 , 58 are preferably beveled sloping downward toward the interior of the lower half 14 for corresponding alignment with the beveled upper edges 34 , 36 , 38 , 40 . The lower half 14 further includes an opening 60 for drawing air from the interior space 22 . In this manner, a vacuum may be created within the interior space 18 for forming the sheet 16 , as will be described in further detail below.
As seen in FIG. 4 a series of retention mechanisms 62 are preferably included around the perimeter of the upper half 12 and are operatively disposed within the sidewalls 44 , 46 , 48 , 50 of the upper half 12 . As best shown in FIG. 5A , the sidewalls 44 , 46 , 48 , 50 include a series of cavities 64 therein having openings 66 through the beveled lower edges 52 , 54 , 56 , 58 . The retention mechanisms 62 each include a retention pin 68 that is partially disposed within the cavity 64 . The retention pin 68 includes a pin portion 70 slidably disposed in and extending outwardly through the opening 66 and an enlarged diameter head 72 slidably disposed within the cavity 64 . The pin portion 70 includes a rounded end face 71 . The retention mechanism 62 further includes a spring 74 disposed between an upper face 76 of the cavity 64 and a top face 78 of the retention pin 68 . The spring 74 biases the retention pin 68 downward through the opening 66 . Also included is an access cover 77 for providing access to the cavity 64 . The access cover 77 runs the length of the cavity 64 and is held in position by a series of screws 79 . In this manner, the retention mechanisms 62 can be assembled into and accessed within the sidewalls 44 , 46 , 48 , 50 .
The retention mechanism 62 retains the sheet 16 in position between the upper and lower halves 12 , 14 throughout the hereindescribed forming process, whereby the rounded end face 71 of the pin portion 70 is biased into contact with the sheet 16 . It will be appreciated, however, that the retention mechanisms 62 may be alternatively housed within the sidewalls 26 , 28 , 30 , 32 of the lower half 14 , whereby the spring 74 biases the retention pin 68 upward through the opening 66 .
A sensing mechanism 80 is provided and is mounted to the sidewall 28 of the lower half 14 . In accordance with a first preferred embodiment, the sensing mechanism 80 includes a laser 82 . The laser 82 selectively generates a beam of laser light 84 that travels across the interior space 18 of the lower half 14 and is reflected by a reflector 86 , fixedly attached to the side wall 32 . The laser 82 includes a sensor for sensing the reflected beam 84 . In accordance with a second preferred embodiment, the sensing mechanism 80 includes an optical sensor such as a video camera or the like. The beam emitted by the sensing mechanism 80 or the line of sight is positioned so as to be intersected and/or interrupted by the lowest most point of sheet 16 as it is formed to its finished shape. When this point is detected by sensor 80 , sensor 80 generates a control signal to discontinue the vacuum as well as to trigger a cooling stage, as will be described in further detail hereinbelow.
The cooling mechanisms 20 are disposed within the interior space 22 of the upper half 14 , fixedly attached to the top wall 42 . In a first preferred embodiment, the cooling mechanisms 20 include fans for circulating air through the interior space 22 of the upper half 14 . Alternatively, it is anticipated that the cooling mechanisms 20 may also include other air blowing or circulating means known in the art, such as blowing ducts and the like which may draw air from outside mold 10 or may include apparatus for cooling the air being circulated thereby. The cooling mechanisms 20 circulate cooling air for cooling the sheet 16 after forming, as described in further detail hereinbelow.
The forming mold 10 further includes trimming means 88 for trimming edges of the sheet 16 as defined by the external shape of the forming mold 10 . In a first preferred embodiment, the trimming means 88 includes a series of blades 90 fixedly attached about the perimeter of the upper half 12 by bolts 91 . The blades 90 extend downward past the lower edges 52 , 54 , 56 , 58 of the sidewalls 44 , 46 , 48 , 50 and include a sharpened leading edge 92 . As the upper and lower halves 12 , 14 come together to retain the sheet 16 therebetween, the blades 90 simultaneously cut through the sheet 16 , cutting away excess material and forming a perimeter of the sheet 16 as defined by the perimeter of the forming mold 10 . As shown the pin portion 70 preferably extends past the leading edge 92 so as to contact the sheet 16 prior to the engagement of the sharpened leading edge 92 therewith so as to insure it is securely retained in position during the trimming operation. Additionally, it should be noted that in a preferred embodiment, as shown in FIG. 5B , there are a plurality of blades 90 along each edge with each leading edge 92 being angled relative to the surface of the sheet 16 so as to provide a series of progressive trimming sections along each side of sheet 16 and thus reduce the force required to accomplish same.
It is also anticipated that alternative trimming means 88 may be implemented for trimming the perimeter of the sheet 16 . Such means include a laser, a high-speed water jet, and the like. In such an arrangement, a laser trimming or water jet trimming mechanism may be provided to orbit the perimeter of the forming mold 10 , trimming away excess material as it travels. After the mold has been moved to a closed position. An exemplary embodiment of the alternative trimming means in detailed in FIG. 7 .
A controller 100 is provided and is in electrical communication with various components of the forming mold 10 , including the sensing mechanism 80 and the cooling mechanism 20 . Depending upon the particular embodiment, the controller 100 may also be in electrical communication with laser or water jet trimming mechanisms for controlling their activity. The controller 100 controls the forming process as discussed in detail below.
The present invention provides a method of forming the sheet 16 of polymeric material, preferably utilizing the above-detailed forming mold 10 . With particular reference to FIG. 8 , the method of the present invention will be described in detail. Initially, at step 200 , the sheet 16 is loaded into the frame 17 . The sheet 16 is heated in one or more stages, represented as steps 210 , 220 , 230 , until it is heated past a glass transition temperature, achieving a glass-transition stage, thereby becoming viscous or rubbery. It should be noted, however, that the sheet should not be heated to the point that it reaches a melting temperature, whereby the sheet would melt and become, scrap. The number of heating stages, their respective lengths and temperatures, may vary in accordance with the type of material and thickness of material used. Heating the sheet 16 in stages is believed preferable to avoid possible blistering or other deformation of the surface of the sheet 16 that could otherwise occur.
The sheet 16 is subsequently brought into the forming stage, at step 240 , and placed on top of the lower half 14 , with a bottom surface 102 resting on the upper edges 34 , 36 , 38 , 40 of the sidewalls 26 , 28 , 30 , 32 . The upper half 12 travels downward in alignment with the lower half 14 , whereby the lower edges 52 , 54 , 56 , 58 of the side walls 44 , 46 , 48 , 50 engage an upper surface 104 of the sheet 16 thereby forming the area around the periphery of the sheet 16 to the contour of edges 52 , 54 , 56 , 58 and retaining the sheet 16 between the upper and lower edges. The frame holds the perimeter of the sheet 16 in rigid form, and thus the sheet 16 is pulled and stretched as it is enclosed within the forming mold 10 . Concurrently, the retention mechanisms 62 provide a downward force, biasing the bottom surface 102 of the sheet 16 into tight engagement with the upper edges 34 , 36 , 38 , 40 of the sidewalls 26 , 28 , 30 , 32 , creating an airtight seal therebetween. Additionally, the edges of the sheet 16 are trimmed in accordance with the perimeter shape of the forming mold 10 . In accordance with the preferred embodiment, trimming of the sheet 16 occurs concurrently with the closing of the upper and lower halves 12 , 14 , whereby the blades 90 cut through the sheet 16 as the upper half 14 engages the upper surface 104 of the sheet 16 . In an alternative embodiment, however, trimming may occur subsequent to the upper and lower halves 12 , 14 closing, whereby a laser or water-jet trimming mechanism travels about the perimeter of the forming mold 10 or the knives may be movable relative to upper half 12 and employ a separate activating mechanism to perform the trimming operation. Alternatively, the trimming operation may be performed once sheet 16 has been formed by any one of a laser, water-jet or separately actuated knives.
Once the sheet 16 is retained between the upper and lower halves 12 , 14 , a vacuum is created within the interior space 18 of the lower half 12 by drawing air from the interior space 18 , through the opening 60 . The vacuum is achievable due to the airtight seal between the bottom surface 102 of the sheet 16 and the upper edges 34 , 36 , 38 , 40 of the sidewalls 26 , 28 , 30 , 32 . As a result, the sheet 16 is drawn downward by the vacuum force into the interior space 18 , thus forming the desired shape. The sensing mechanism 80 senses when the sheet achieves a particular draw depth within the interior space 18 . Upon sensing the sheet 16 achieving the draw depth, the cooling mechanisms 20 are activated for cooling the sheet 16 below its glass-transition temperature, thereby again achieving a rigid state. The vacuum is held at steady state during the cooling process and is not relieved until the sheet 16 is sufficiently cooled. The cooling time of the sheet may be monitored by the controller 100 , which controls each of the above-described activities. Once the sheet 16 is sufficiently cooled, the vacuum is relieved from the lower half 14 and the upper half 12 withdraws. The frame 17 , with excess sheet material, are also withdrawn, thereby leaving the formed sheet 16 accessible for removal from the forming mold 10 . This is best shown in FIG. 6 . A secondary clamping mechanism 110 is used to grasp a perimeter edge of the sheet 16 and carry it through the remaining processes.
Subsequent to the forming process, the frame and excess material are carried away at step 250 for reprocessing of the excess material and the formed sheet 16 undergoes several finishing processes for producing an end product. These stages preferably include a first quality check, at step 260 , primer and coating stages at steps 270 , 280 , respectively, and a second quality check at step 290 . The first and second quality checks 260 , 290 are preferably achieved using optical means, such as a camera, for checking the polymeric sheet 16 for any distortion, scratches and/or abrasions. The primer and coating stages 270 , 280 preferably include a wash substep, preferably with water, to remove any dust or other particles from the surfaces of sheet 16 followed by a drying stage and then priming via dip, flow coating or spray process, a primer drying sub-step, a hard coat application by dip, flow coating or spraying process sub-step and a hard coat drying sub-step. It will be appreciated, however, that the hereindescribed finishing processes are merely exemplary in nature and may be substituted for or further include any one of a number of other finishing processes commonly known in the art. Finally, at step 300 , the finished sheet 16 is packaged for customer delivery.
It should be noted that at least the primer and coating stages will be performed under strict temperature humidity and dust controlled conditions to ensure proper flow free coating of sheet 16 . The primer coat may be of any suitable material capable of providing a clear distortion free bond with sheet 16 and the top coat. At present, the preferred primer and top coating materials are experimental materials supplied by General Electric Co. applied by a flow coating process that are believed to offer an improved life span of 8-10 years which is significantly longer than currently available materials which may be utilized for this purpose. Preferably the primer and hard coat will be applied to both surfaces of sheet 16 .
Although FIG. 8 and the supporting description herein, describe a generally linear processing line for forming polymeric material, it will be appreciated by those skilled in the art that the processing line may vary in layout. For example, it is anticipated that the processing line may be a rotary line, whereby the processing steps are generally organized as a circle. In this manner, the sheet 16 rotates about the circular layout through each of the processing stages for forming the finished product.
While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to provide the above-stated advantages, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims. | A base sheet of transparent polycarbonate material has a formed shape including a center portion and a peripheral portion. The center portion is formed by a non-contact forming operation occurring at a temperature above the glass transition temperature and below the melt temperature of the transparent polycarbonate material, thereby resulting in the center portion of the base sheet being free of visual distortion. A top coat layer is disposed over the base sheet. The top coat layer has a greater resistance to abrasion than the polycarbonate material and provides UV protection to the base sheet. A primer coating is disposed between the base sheet and the top coat layer to facilitate bonding therebetween. The peripheral portion can have a shape created by a contact forming operation occurring at a temperature above the glass transition temperature and below the melt temperature of the polycarbonate material. | 1 |
CROSS RELATED APPLICATION
[0001] This applications claims priority to U.S. Provisional Patent Application Ser. No. 61/157,446 filed Mar. 4, 2009, the entirety of which application is incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] Webs of material (including but not limited to tissue paper, towel paper, other papers, board, plastics, and polymers) are transported through spans that typically have web stabilizers, such as shown in U.S. Pat. No. 4,321,107. The webs move at a relatively high speed through the spans and across the stabilizers.
[0003] Stabilizers traditionally have a generally flat or planar surface against which the web moves as the web traverses a span. The stabilizer is positioned adjacent the web such that the web is a short distance from the flat surface of the web. The web moves at a high speed, such as 4,000 to 7,000 feet per minute (1,200 to 2,100 meters per minute). The movement of the web induces air flows on both the top and bottom sides of the web. The air flow tends to move at the same speed as the web.
[0004] The web may flutter due to disturbances in the air flows on either or both sides of the web. Disturbances may be caused by the laminar air stream immediately adjacent the web, e.g. the air flow boundary layer, to separate from the web such that a disturbed airflow is adjacent the web.
[0005] A web stabilizer having a surface immediately adjacent the web reduces the tendency of the web to flutter. U.S. Pat. Nos. 4,321,107 and 4,906,333 disclose examples of web stabilizers. As the web moves across the surface of the stabilizer, the stabilizer provides a physical barrier to web flutter in the direction the stabilizer and tends to smooth the air flow between the stabilizer and web. By smoothing the air flow, a laminar boundary layer air flow may be maintained adjacent the web, which reduces flutter of the web.
[0006] A difficulty with conventional stabilizers is that the web tends to fall away from the surface of the stabilizer, especially if the surface is long in the direction of web travel and the web travels below the stabilizer. Bump bars have been added to the leading edges of stabilizers to reduce flutter. A bump bar is a pipe or bar (circular in cross-section) welded to the leading edge of the stabilizer and extending below (in the direction of the web) the stabilizer such that the web first moves over the bar before moving over the bottom surface of the stabilizer.
[0007] Another approach to overcome the difficulty of web flutter below a stabilizer is to inject a high velocity air stream in the gap between the stabilizer surface and web, such as disclosed in U.S. Pat. No. 6,325,896. The high velocity air reduces the air pressure between the web and stabilizer. The reduced air pressure draws the web towards the stabilizer. However, injecting a high velocity air stream requires an air supply, air ducts and air jets or slots, which increase the cost to make and operate a stabilizer. Further, the air injection nozzles and slots are subject to clogging.
[0008] Another approach is to shape the stabilizer as an airfoil such that a low pressure is formed between the stabilizer and the web, as disclosed in U.S. Pat. No. 6,325,896. However, an airfoil shaped stabilizer, that is long relative to the direction of web travel, has difficultly in reducing flutter in the downstream region of the stabilizer. There is a need for web stabilizers that suppress web flutter over long stabilizer surfaces, have low manufacturing and operating costs, and are not susceptible to clogging of air injection nozzles and slots.
BRIEF DESCRIPTION OF THE INVENTION
[0009] A web stabilizer has been developed having one or more transitions in the surface facing the web. These transitions may be transverse to the direction of web travel, such as a ridge or step extending the width of a stabilizer or an array of recesses and protrusions on the surface of the stabilizer. Because of the transitions and the movement of the web, a low pressure region is formed immediately downstream of each transition in the direction of web travel. These low pressure regions create a pressure differential between opposite sides of the web that draw (bias) the web towards the surface of the stabilizer.
[0010] The transitions in the surface of the web stabilizer create low pressure regions between the web and stabilizer, preferably without injection of high velocity air at the transitions. By arranging the transitions at various locations on the surface of the stabilizer, the low pressure regions formed by the transitions draw the web towards the stabilizer along the length of the stabilizer. The transitions on stabilizers with long surfaces above a web assist in reducing flutter in the web along the entire length of the stabilizer.
[0011] Various transition shapes and arrangements of transitions on the stabilizer, such as disclosed herein, are in accordance with the invention. The shapes of transitions include: steps, ridges and grooves extending the width of the surface of a stabilizer and transverse to the direction of web travel; air passages extending from the surface of the stabilizer and facing the web to an exhaust port discharging air to atmospheric pressure or to a suction device such as a dust collector, where the passages are preferably tilted away from the direction of web travel; and arrays of protrusions and recesses on the surface of the stabilizer, wherein the protrusions and recesses are preferably widest in a direction transverse to the direction of web travel.
[0012] Further, the surface of the stabilizer between the transitions may be linear, curved, undulating or otherwise shaped. The various shapes and arrangements of transitions on the surface of the stabilizer between the transitions promote a low pressure zone between the stabilizer surface and the web and reduce web flutter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1A is a diagram of a web moving across a stabilizer having a step transition.
[0014] FIG. 1B is a diagram of a web moving across a stabilizer having a surface with a step transition.
[0015] FIG. 2 is a schematic side cross-sectional view of a web stabilizer having a surface with step (square) transitions and planar surface regions between the transitions, where the planar surface regions are substantially parallel to each other and to the direction of web travel.
[0016] FIG. 3 is a schematic side and cross-sectional view of a web stabilizer having a surface with step (concave or fillet) transitions and planar surface regions between the transitions, where the planar surface regions are substantially parallel to each other and to the direction of web travel.
[0017] FIG. 4 is a schematic side and cross-sectional view of a web stabilizer having a surface with step (square) transitions and planar surface regions between the transitions, where the planar surface regions are substantially parallel to each other and are inclined with respect to the direction of web travel.
[0018] FIG. 5 is a schematic side and cross-sectional view of a web stabilizer having a surface with step (square) transitions extending the width of the stabilizer and the stabilizer has concave surface regions between the transitions.
[0019] FIG. 6 is a schematic side and cross-sectional view of a web stabilizer having a planar surface which is generally parallel to the direction of web travel, the surface has grooves or concave transitions extending the width of the surface at intervals along the length of the surface.
[0020] FIG. 7 is a schematic and side cross-sectional view of a web stabilizer having a planar surface which is generally parallel to the direction of web travel, the surface has slots or passages preferably extending traverse to the direction of web travel, where the slots or passages allow air from between the web and stabilizer surface to exhaust and thereby form low pressure regions at the inlet to slots and passages on the surfaces.
[0021] FIG. 8 is a schematic and side cross-sectional view of a web stabilizer having a surface with an array of recesses and protrusions.
[0022] FIG. 9 is a schematic plan view of the surface of the stabilizer shown in FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIGS. 1A and 1B show a portion of a tissue machine 10 in which a web 12 moves across a span 13 between components 11 , e.g., a calendar and a roller, of the machine. A stationary stabilizer 1 is fixed immediately above the web and in the span such that the web moves across a lower surface 14 that is generally parallel to the web.
[0024] The lower surface 14 of the stabilizer has a bump bar transition 16 extending across the width (W) of the stabilizer. The bump bar 16 forms a step in the lower surface 14 . As the web 12 moves (direction of travel 19 ) over the bump bar, the web is drawn up to the rearward area 17 of the lower surface. The web is pulled up because a low pressure region is formed immediately downstream of the bump bar 16 in the gap between the lower surface and the web. Because the web is pulled up to the lower surface 14 , the tendency of the web to flutter is reduced.
[0025] The transitions 16 may be arranged at various locations along the length of the lower surface of the stabilizer. For example, transitions may be arranged at intervals of one third the length of the lower surface. Preferably, a least one transition 16 is at the upstream half or third of the length of the lower surface 14 of the stabilizer in the direction 19 of web travel and another transition is at the downstream half or third of the length of the lower surface of the stabilizer. Transitions at the downstream half or third of the stabilizer assist in reducing flutter in the web as the web moves past the stabilizer.
[0026] FIG. 2 shows a stabilizer 21 having a lower surface 14 with substantially parallel surfaces 2 , 3 and 4 that are generally planar and arranged sequentially along the direction 19 of web travel. The surfaces 2 , 3 , and 4 may be substantially parallel with each other and to the direction of web travel. The surfaces 2 , 3 and 4 may extend the width of the web and lower surface of the stabilizer.
[0027] Separating each of the parallel surfaces 2 , 3 and 4 , are substantially square step transitions 5 that preferably extend the width of the stabilizer and are transverse to the direction of web travel 19 . These square transitions 5 form a step having right angled corners between surfaces 2 and 3 and between surfaces 3 and 4 . The step may have a height dimension in a range of, for example, 0.25 inches to 0.75 inches (6.3 to 19 millimeters—mm). The step may also be shorter than this range and have a height, for example, of 0.06 inches (1.5 mm). The step may also be greater than this range and a height, for example, of 1.5 inch (38 mm).
[0028] The height of the step transition 5 may be determined to avoid interfering with, e.g., tearing, the web and to form a low pressure region immediately downstream of the step and between the surface of the stabilizer and the web. The transitions 5 may extend substantially the full width of the stabilizer or the width of the web.
[0029] The transition 5 may be substantially perpendicular to the direction of web travel. Alternatively, the transitions may be oblique to the direction of web travel, such as at an angle of 75 degrees to 89 degrees to the direction of web travel. Further the transition may not form a straight line and have portions that are perpendicular to the web travel and other portions that are canted with respect to the direction of web travel.
[0030] The transition may be formed by making corners or sloped surfaces in the lower surface of the stabilizer, by overlapping plates on the lower surface where the plates are separated by a narrow gap, or by some other irregular shape on the lower surface of the stabilizer.
[0031] The square transitions 5 may be formed of one or more bars or other machined pieces that are fixed, e.g., welded or fastened, to the lower surface of the stabilizer. The square transitions 5 may form structural supports for panels forming the surfaces 2 , 3 and 4 . The joints between the square transitions 5 and panels forming the surfaces 2 , 3 and 4 may be sealed to avoid air entering or escaping from or to an interior portion of the stabilizer. Alternatively, the joints may not be sealed such that the air pressure in the region immediately downstream of each transition equalizes with an air pressure, e.g., ambient atmospheric pressure, inside the body of the stabilizer.
[0032] FIG. 3 shows a stabilizer 23 with substantially parallel planar regions 2 , 3 and 4 on a lower surface 14 of the stabilizer. Similar to the stabilizer 21 shown in FIG. 2 , the planar regions 2 , 3 , and 4 are separated by transitions that extend the width of the stabilizer and are generally transverse to the direction 19 of web travel. The transitions 16 form steps between the regions 2 and 3 and between regions 3 and 4 .
[0033] The transitions 15 are concave or filleted step or otherwise curved steps at the joints between the surfaces 2 , 3 and 4 . The transitions 24 may be formed from one or more pieces, e.g., bars, machined to form a concave, filleted or curved shape 25 . The pieces of the transition 24 are manufactured and assembled, e.g., welded or fastened, to the stabilizer and may provide structural support for the panels forming the regions 2 , 3 , and 4 . The concave or filleted shape 25 of the transition 24 reduces the open corner volume at the transition as compared to the square transition shown in FIG. 2 and thereby minimizes dust and contamination build-up in the transition corner volume immediately downstream and adjacent to the curved shape 24 of the transition.
[0034] FIG. 4 shows a stabilizer 30 with substantially flat lower surfaces 31 , 32 and 33 and a square step transition 34 between these surfaces. The lower surfaces may not be parallel to the web direction and may be parallel to each other. The lower surfaces 31 , 32 and 33 may be inclined with respect to the web direction at an angle of 2 to 10 degrees such that the surfaces slope towards the web in the direction 19 of web travel. The transitions 34 may be substantially the full width of the stabilizer 30 and substantially perpendicular to the direction of web travel.
[0035] FIG. 5 shows a stabilizer 40 having a lower surface with concave surface regions 25 , 26 and 43 , separated by step transitions 44 . The concave surface regions may or may not be parallel with the direction of web travel. The transitions 44 may be substantially the full width of the stabilizer 40 or the web, and substantially perpendicular to the direction 19 of web travel. The transitions 44 may be formed in the same manner as the transitions shown in FIGS. 2 to 4 . The concave surface regions 41 , 42 and 43 may be panels bowed to form a concave shape and supported at the transitions 44 and by the internal supports 45 in the stabilizer, such as internal ribs and support grids. These internal supports may also be included in the other stabilizers disclosed herein. Further, the surface regions 41 , 42 and 43 may have convex surfaces rather than the concave surfaces shown in FIG. 5 .
[0036] FIG. 6 a stabilizer 46 with a lower surface formed of parallel surfaces 47 separated by substantially concave transitions 48 , e.g., grooves. The surfaces 47 are substantially parallel with the web direction. The transitions 48 may extend substantially the full width of the stabilizer and be substantially perpendicular to the direction of web travel. The surfaces 47 may be substantially planar with each other and interrupted by the recessed transition slots 48 . The transition slots 48 may be one or more pieces, e.g., bars, machined to have grooves forming the transition slots. The pieces are mounted in the stabilizer and may provide structural support for the panels forming the surfaces 47 .
[0037] FIG. 7 shows a stabilizer 50 having a lower surface that may be formed of substantially parallel lower surface sections 51 , 52 and 53 separated by slots, other air passages or open areas 54 . The surface(s) 51 , 52 and 53 may be in a plane substantially parallel with the web direction and may be parallel to each other.
[0038] The slots, air passage or open areas (collectively transitions) 54 may extend the width of the stabilizer (or the width of the web) and be generally perpendicular (or oblique) to the direction of web travel. The transitions 54 may be formed by one or more pieces, e.g., bars, machined to an appropriate shape and assembled, e.g., welded or fastened, in the stabilizer to form the slots, passage or open areas.
[0039] The transitions 54 have air inlets adjacent the lower surface sections 51 , 52 and 53 . The transitions 54 have outlets 55 that exhaust air from a surface of the stabilizer distant from the lower surfaces 51 , 52 and 53 or to an internal air duct in the stabilizer. The outlets 55 may exhaust to the atmosphere at an ambient air pressure or to another device, such as a dust collection system 56 , e.g., a vacuum, that applies suction to the outlets 55 and transitions 54 to draw air from the inlets to the transitions. The ducts of the transitions 54 may be inclined, e.g., at an angle of 30 to 55 degrees with respect to the lower surfaces 51 , 52 and 53 and sloped such that the inlet is upstream of the outlet 36 in the direction of web travel. The transitions 54 allow a portion of the air moving with the web and between the web and the lower surfaces 51 , 52 and 53 to flow into the transitions and thereby create a low pressure region between the web and the lower surfaces.
[0040] FIGS. 8 and 9 show a stabilizer 60 with a lower surface 62 that may be in a plane substantially parallel to the web. The lower surface may have convex or concave regions, and step transitions as shown in FIGS. 2 to 7 .
[0041] The lower surface 62 includes an array of transitions 64 which may be undulating regions in which the surface gradually rises and falls from the web. For example, the transitions may include recesses or protrusions 64 that have a width dimension perpendicular to the direction of web travel that is substantially greater than a length dimension. For example, a transition 64 may be a generally rectangular bump on the lower surface 62 having a width of between 50 mm to 500 mm, a length (parallel to web travel) of 20 mm to 200 mm and a height of 5 to 20 mm. These transitions 64 may have a sloped leading edge facing the direction 19 of web travel and a sharp cornered, e.g., 90 degree corners, trailing edge to form air disturbances and low pressures immediately downstream of the transitions.
[0042] The transitions 64 may be arranged in an array such that the transitions are arranged in rows parallel to the direction of web travel and the transitions are staggered from row to row as shown in FIG. 9 .
[0043] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A web stabilizer adapted to stabilize a web moving across a span between two components of a web machine or machines, the stabilizer including: a surface facing and adjacent the moving web, and at least one transition in the surface of the stabilizer, wherein the transition is a protrusion or recess in the surface between a leading edge of the stabilizer facing a direction of web travel and a trailing edge of the stabilizer. | 3 |
FIELD OF THE INVENTION
This invention relates to a process and apparatus for the recovery and purification of refrigerant with a solid adsorbent. More particularly, this invention relates to an efficient process and apparatus for recovering and purifying refrigerant discharged from sources such as automobile air conditioners, home refrigerators and commercial refrigeration facilities.
BACKGROUND OF THE INVENTION
Refrigerants are used throughout the world in machines to provide temperature control in the industrial areas of food processing, storage, and distribution in mechanical air conditioning for homes, buildings and automobiles, and in the chemical industry. Since 1860, with the development of the basic concepts of today's refrigeration system, refrigerants for vapor-compression systems were sought which were stable, incombustible, nontoxic and nonirritating chemical fluids which vaporize and condense at pressures and temperatures appropriate for their application. In about 1930, it was discovered that certain halogenated hydrocarbons having chlorine and fluorine atoms could be employed as "safe" refrigerants. These halogenated hydrocarbons include chlorofluorocarbons (CFC's) and hydrochlorofluorocarbons (HCFC's). Recently, it was discovered that some of these "safe" refrigerants are harmful to the environment, and in particular, the release of CFC's to the atmosphere could lead to damaging of the earth's ozone layer. In the atmosphere they can migrate to the stratosphere where photolysis reactions release the chlorine atoms, which can react with ozone. As a result many Western countries have regulations for the elimination of production of CFC's by Jan. 1, 1996. HCFC's have a hydrogen atom in the molecule which can reduce the stability of the compound relative to CFC's. HCFC's are now considered part of the ozone depletion problem and their production is to be phased out (eliminated) by the year 2030. Hydrofluorocarbons (HFC's) are the replacements for CFC's and HCFC's. Examples of CFC's, HCFC's, and HFC's are given in Table 2 of the 1993 ASHRAE FUNDAMENTALS HANDBOOK, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, Ga. page 16.4, which is herein incorporated by reference. Because CFC's and HCFC's may be found in the refrigeration systems of old refrigerators, automobiles, and commercial refrigeration facilities, it is desired to have a "safe", simple and economical way of recovering and/or purifying these compounds with a minimum risk of their release to the environment.
Typically, during the continued operation of a refrigeration system, the refrigerant becomes contaminated with impurities such as water vapor, air, acids and particulate matter. In the past, when a refrigeration system needed repair, the standard practice was to vent or bleed the refrigerant to the atmosphere. This technique wasted refrigerant, which can be cleaned and reused, and added a material to the atmosphere, which is now known to cause damage to the ozone layer.
Various methods have been employed to recover and purify refrigerant from refrigeration units. Some of these methods remove the contaminated refrigerant from the refrigeration units, expand the contaminated refrigerant and remove the impurities by condensation. U.S. Pat. No. 4,939,903 to Goddard is an example of this impurity condensation approach. In these systems, it is critical to maintain the system under pressure at all times to prevent any leakage of the refrigerant to the atmosphere.
Others have developed devices for receiving and dispensing a gaseous refrigerant. For example, U.S. Pat. No. 5,165,247 discloses such a device comprising a pressurized vessel, containing an adsorbent, wherein the adsorbent is secured to a heat exchange surface. The pressurized vessel is connected to refrigeration systems to collect or refill the refrigeration system using either cooling to adsorb refrigerant during a collection operation, or heating to desorb refrigerant during a refill operation.
The U.S. Pat. No. 5,094,087 discloses an apparatus incorporating a purifying filter for reclaiming and recovering volatile liquids such as a refrigerant contained in a closed network. The purifying filter includes an oil mist filter and a moisture adsorbing filter, and the filters are arranged in a flow connection between a discharge side of the compressor and the condenser in a refrigeration system. The filters are periodically removed from the closed net work by switch valve means for air drying.
European Patent No. EPO317709B1 discloses a process for disposing of refrigerant from sealed refrigeration systems by opening the system allowing the refrigerant to depressurize and flow to a collecting vessel containing an activated carbon adsorbent. The activated carbon adsorbent adsorbs the refrigerant and permits any air in the system to pass through the collecting vessel, or a group of such vessels connected in series to one another.
In another similar device, U.S. Pat. No. 5,245,839 discloses an apparatus which employs an adsorbent to adsorb refrigerant in a vessel. The adsorbed refrigerant is desorbed with heat to provide a refrigerant gas which is subsequently condensed to a liquid, dried to remove water from the liquid and purged to remove non-condensable gas before returning the refrigerant liquid to a refrigerant reservoir.
U.S. Pat. No. 5,231,980 to Filipovic et at. discloses a process for the recovery of halogenated hydrocarbons from a gas stream, such as anaesthesia in patient exhalent, by passing the gas through a hydrophobic high silica zeolite molecular sieve having a silica to alumina ratio (SiO 2 /Al 2 O 3 ) of about 12 or greater. The process passes the gas stream through the adsorbent material until just prior to breakthrough. The adsorbed halogenated hydrocarbons are removed from the adsorbent by purging the adsorbent with an inert gas stream at desorption conditions. The halogenated hydrocarbons are subsequently removed from the purging gas stream by condensation, and the condensate is purified by fractional distillation for reuse. The preferred high silica zeolite adsorbent is silicalite.
All of these devices employ separate purification steps requiring additional equipment and liquid or gas handling steps which complicate the process of recovering and purification of refrigerants and increase the risk of escape of refrigerant to the atmosphere. Processes are sought which combine the steps of collecting and purification without requiring additional separation, filtering and purging steps.
Methods are sought which provide for low energy collection and recovery of the refrigerant with a minimum risk of loss of any refrigerant to the environment and with a minimum use of energy in that recovery.
SUMMARY OF THE INVENTION
The present invention may be employed to recover and purify halogenated hydrocarbons. The most common source of these halogenareal hydrocarbons is from vapor-compression refrigeration systems. The present invention may be employed to recover halogenated hydrocarbons from discarded refrigeration systems such as old refrigerators, junked automobile air conditioners and commercial refrigeration systems. The process of the present invention may be used either in a continuous manner whereby refrigerant is both recovered and purified, the process may be terminated following the recovery or adsorption steps in one location and the process continued for the desorption and regeneration steps at another location to provide a recovered and purified refrigerant stream.
The invention can employ an adsorbent material which was found at ambient conditions to have a surprisingly high capacity for adsorbing refrigerants with a correspondingly low selectivity to impurities such as oxygen, nitrogen, carbon monoxide, carbon dioxide, and small quantities of water in the liquid and vapor phase normally present in refrigeration systems.
The present invention is a process for the recovery and purification of a contaminated refrigerant stream comprising halogenareal hydrocarbons and impurities. The impurities include water and air. The process comprises a series of sequential steps. The contaminated refrigerant stream is passed through a first bed of a molecular sieve adsorbent. The adsorbent is selective for the adsorption of halogenated hydrocarbons, whereby the halogenated hydrocarbons are selectively removed from the contaminated refrigerant stream forming a halogenated hydrocarbon front in the first bed. A first vent gas stream comprising the impurities is withdrawn from the first bed. The first vent gas stream is passed to a second bed of the molecular sieve adsorbent. The passing of the contaminated refrigerant stream to the first bed is continued until at least a portion of the halogenareal hydrocarbon front has moved into the second bed. A second vent gas comprising the impurities is withdrawn from the second bed. The passing of the contaminated refrigerant stream is terminated and the first bed is isolated. The first bed is heated to desorb refrigerant from the first bed. A purified refrigerant stream is recovered and a regenerated first bed is provided.
In another embodiment the present invention relates to the use of an adsorbent for the recovery and purification of a contaminated refrigerant stream comprising halogenated hydrocarbons from a mixture thereof with water and air. The adsorbent is selected from the group consisting of ZSM-5, low cerium rare earth exchanged zeolite Y, low cerium rare earth exchanged steamed zeolite Y, mordenite, Breck Structure Six, ECR-32, faujasite having a SiO 2 /Al 2 O 3 ratio less than about 20, and mixtures thereof.
In other embodiments the invention relates to a process for the purification and recovery of a contaminated refrigerant stream comprising halogenated hydrocarbons and impurities including water and air. The contaminated refrigerant stream is passed through a first bed of a molecular sieve adsorbent selective for the adsorption of halogenareal hydrocarbons, whereby the halogenated hydrocarbons are selectively removed from the contaminated refrigerant stream forming a halogenated hydrocarbon front in the first bed. A first vent gas stream comprising the impurities is withdrawn from said first bed. The first vent gas stream is passed to a second bed of the molecular sieve adsorbent. The passing of the contaminated refrigerant stream to the first bed is continued until at least a portion of the halogenated hydrocarbon front has moved to the second bed. A second vent gas comprising the impurities is withdrawn from the second bed. The passing of the contaminated refrigerant stream is terminated and the first bed is isolated. The first bed is sealed and replaced with another bed containing the molecular sieve adsorbent. The contaminated refrigerant stream is passed to the other bed and a third vent gas stream comprising impurities is withdrawn. The third vent gas stream is passed to the other bed until at least a portion of the halogenated hydrocarbon front has moved into the second bed. The steps of sealing and replacing the first bed with the other bed and passing the contaminated refrigerant therethrough until the halogenated hydrocarbon front moves into the second bed are repeated. The passing of the contaminated refrigerant to the other bed is terminated prior to the breakthrough of the halogenated hydrocarbons from the second bed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram of the process of the invention.
FIG. 2 is a schematic flow diagram of an alternate process of the invention.
FIG. 3 is a graph showing a refrigerant adsorption isotherm for a low cerium-rare earth exchanged zeolite Y-84 adsorbent.
FIG. 4 is a graph showing a refrigerant adsorption isotherm for a low cerium rare earth-exchanged zeolite LZ-210.
FIG. 5 is a graph showing breakthrough curves for refrigerant R-22 in a bed of silicalite over a range of feed velocities.
FIG. 6 is a graph showing breakthrough curves for refrigerant R-12 in a bed of silicalite over a range of feed velocities.
FIG. 7 is a graph showing the length of the R-22 mass transfer adsorption front in a bed containing silicalite over a range of feed velocities.
FIG. 8 is a graph showing the length of the R-12 mass transfer adsorption front in a bed containing silicalite over a range of feed velocities.
DETAILED DESCRIPTION OF THE INVENTION
The process of the instant invention relates to the recovery of refrigerants from refrigeration systems. The term refrigerants refers to halogenated hydrocarbons including chlorofluorocarbons (CFC's), hydrochlorofluorocarbons (HCFC's), and hydrofluorocarbons (HFC's). More particularly, the invention relates to a method for the recovery, the reclamation and the recycling of refrigerant employing a unique purification step. The term `recovery` refers to the removal of refrigerant from a refrigeration system into a tank or reservoir with a minimal emission of refrigerant to the atmosphere. The term `reclamation` refers to the processing of recovered refrigerant usually at a remote site to remove contaminants and returning a purified refrigerant to original refrigerant quality specification. Reclamation is typically accompanied by some chemical or physical analysis to confirm that the quality specifications are achieved. The term `refrigerant recycling` refers to the processing of recovered refrigerant, usually on the site of the refrigeration system. The refrigerant recycling is typically performed periodically to remove contaminants such as oil, organic and mineral acids, particulates and the like. No analysis procedure is required in refrigerant recycling before returning the purified refrigerant to the refrigeration system. In addition to the above contaminants, impurities such as air, water, and inert gases build up in refrigeration systems as a result of mechanical leaks in the system and leaks which develop during refrigerant transfers to and from the system. These impurities reduce the efficiency of the refrigeration system and must be removed. Typically, the buildup of impurities in refrigerant tanks and systems is removed by releasing a mixture of the refrigerant and the impurities to the atmosphere. The method of this invention, may be employed to remove impurities such as water and air in refrigerant recovery or in refrigerant recycling operations without emitting refrigerant to the atmosphere. The process of the instant invention employs a lead/trim adsorbent bed configuration and an adsorbent cycle of adsorption and desorption steps which minimize the possibility for emission of the refrigerant to the atmosphere. By the use of adsorption zones in a lead/trim configuration, the refrigerant forms a mass transfer zone in the lead adsorbent bed which travels through the adsorption bed, pushing the non-adsorbed impurities out of the lead bed and leaving essentially pure refrigerant adsorbed on the adsorbent. According to the process of the invention, the adsorption of the refrigerant is continued until the mass transfer zone of the refrigerant has passed through the first adsorption zone (lead) and has progressed into a second adsorption zone (trim) such that essentially all of the impurities have been pushed out of the lead adsorption bed, leaving the essentially pure refrigerant remaining in the lead adsorption bed. At this point the adsorbent beds may be isolated. In one embodiment of the invention following the passage of the mass transfer zone of the refrigerant into the trim bed, the lead bed may be sealed at the feed and effluent ends and the lead bed may be transported to a separate site for the recovery of the purified refrigerant. The trim bed may be used with another lead bed to collect additional refrigerant with the termination of the adsorption step in the lead bed following the progression of the new lead bed mass transfer zone into the trim bed. This process of replacing the lead bed with a fresh adsorbent bed may be continued up to the point prior to refrigerant breakthrough from the trim bed.
In another embodiment for a periodic or semi-continuous refrigerant recovery operation, following the passage of the mass transfer zone through a lead bed, the feed end of the second, or trim bed, is connected to the refrigeration system and refrigerant is permitted to flow through the second bed releasing impurities to the atmosphere directly, while the former lead bed or first adsorbent bed is heated to desorb the adsorbed refrigerant and a purified refrigerant stream is recovered. The purified refrigerant can be returned directly to the refrigeration system as a vapor at a point in the refrigeration system such as upstream of the compressor in the refrigeration system; or, the purified refrigerant can be compressed and cooled to form a condensed liquid and reintroduced to the refrigeration system either downstream of the refrigeration system compressor or to a refrigerant storage tank. Preferably, the second adsorbent bed will have sufficient capacity for adsorption of refrigerant to permit the further adsorption of refrigerant in the second adsorbent bed to permit the freshly regenerated first adsorbent bed to be placed in the trim position at a point in the cycle prior to the breakthrough of refrigerant from the second bed, thus completing the cycle. The adsorbent beds can take the form of bottles or cylinders filed with an adsorbent selective for adsorbing refrigerants and having a feed end and an effluent end with a connecting means such as a line or a flexible line and appropriate fittings to connect the feed end of the adsorbent bed to a refrigeration system, and an effluent end which has a connecting means to connect the effluent end of the adsorbent bed to another adsorbent bed. In this configuration, the adsorbent beds can be interchanged between the lead and trim positions depending upon their capacity. In addition, the adsorbent beds will be provided with a heating means such as a steam heater or electric heater in the form of a core or a jacket to provide heat to desorb the adsorbed refrigerant without requiring a purge gas. The introduction of a purge gas during desorption would reintroduce impurities to the purified refrigerant or require further separation steps to remove the purge gas from the refrigerant. Thus the lead bed is heated to desorb the purified refrigerant. The adsorption step for the collection of refrigerant may be carried out at a remote site and then returned to a central location for the desorption or reclamation step, or both the adsorption and desorption steps may be employed at the site of the refrigeration system to provide a recycling system which returns purified refrigerant directly to the refrigeration system.
Although there are a variety of solid adsorbents which are suitable for use according to the present invention including but not limited to activated carbons, activated clays, silica gel, activated alumina and crystalline molecular sieves, molecular sieves are preferred for adsorption because of their uniform pore size, i.e., effective pore diameter. The term "effective pore diameter" is conventional in the art and is used herein to functionally define the pore size in terms of the size of molecules that can enter the pores rather than actual dimensions which are often difficult to determine as the pores are often irregularly shaped, i.e., non-circular. D. W. Breck, in Zeolite Molecular Sieves, John Wiley and Sons, New York, 1974, at pages 633 to 641, provides a discussion of effective pore diameter which is hereby incorporated by reference. These molecular sieves include, for example, the various forms of silicoaluminophosphates, and aluminophosphates disclosed in U.S. Pat. Nos. 4,440,871, 4,310,440, and 4,567,027, hereby incorporated by reference, as well as zeolitic molecular sieves.
Zeolitic molecular sieves in the calcined form may be represented by the general formula:
Me.sub.2/n O: Al.sub.2 O.sub.3 : xSiO.sub.2 : yH.sub.2 O
where Me is a cation, n is the valence of the cation, x has a value from about 2 to infinity and y has a value of from about 2 to 10.
Typical well-known zeolites which may be used include, chabazite, also referred to as Zeolite D, clinoptilolite, erionite, faujasite, also referred to as Zeolite X and Zeolite Y, ferrierite, silicalite, mordenite, Zeolite A, and Zeolite P. Derailed descriptions of the above-identified zeolites, as well as others, may be found in D. W. Breck, Zeolite Molecular Sieves, John Wiley and Sons, New York, 1974, hereby incorporated by reference. Other zeolites suitable for use according to the present invention are those having a low silica content, i.e. those having silica to alumina ratios less than 50 and preferably less than about 20, more preferably less than about 12, and most preferably a molecular sieve zeolite having silica to alumina ratios of between about 5 and about 12.
Zeolites which are preferred for use in the present invention are those zeolites which permit the desorption of water at moderate to low temperatures and have a relatively low heat capacity. Such preferred zeolites may be selected from the group consisting of faujasite zeolites, and more particularly are selected from the group consisting of zeolite Y-85, low cerium rare earth exchanged zeolite Y-84, Breck Structure Six (BSS), ECR-32, and low cerium rare earth-exchanged LZ-210. Zeolite Y-85 is a steam-stabilized modified zeolite Y the preparation of which is disclosed in U.S. Pat. No. 5,208,197 and is herein incorporated by reference. The low cerium rare earth exchanged zeolite Y-84 is prepared in a manner similar to the preparation of Y-85. The starting material is a form of zeolite Y which has been ion-exchanged with ammonium ions, or ammonium ion precursors such as quaternary ammonium or other nitrogen-containing organic cations, to reduce the alkali metal content to less than about 4.0 wt-% (anhydrous basis) and preferably to less than about 3.0 wt-%. The manner of carrying out this first ammonium ion exchange is not a critical factor and can be accomplished by means well known in the art. A second ammonium ion exchange is carried out in the conventional manner at a pH well above 4.0 and the resulting zeolite is subjected to a rare earth exchange by contacting the zeolite with an aqueous solution of rare earth salt in the known manner. A mixed rare earth chloride salt can be added to an aqueous slurry of the ammonium exchanged zeolite to yield a zeolite product having a rare earth content generally in the range of 3.5 to 12.0 weight percent rare earth as RE 2 O 3 . The product is then water washed and calcined in dry air at a temperature of from about 55° C. to about 850° C., preferably 500° C. to about 750° C. for a period of time to reduce the unit cell dimension to less than 24.8 Angstroms and more particularly in the range of 24.35 to 24.72 Angstroms. The final low cerium rare earth exchanged zeolite Y-84 has a cerium content less than about 0.2 weight percent. Zeolite LZ-210 is defined in a U.S. Pat. No. 4,503,023 in column 12, lines 5-68. The low cerium rare earth exchanged zeolite LZ-210 may be prepared by subjecting the LZ-210 to a conventional rare earth exchange step followed by the dry air calcination step described above, or a steam calcination step wherein steam is introduced during the calcination step according to conventional methods. Preferably the low cerium rare earth exchanged zeolite LZ-210 will be prepared by the process of providing a crystalline sodium zeolite Y starting composition and contacting the starting composition with ammonium cations under cation exchange conditions as exemplified in U.S. Pat. No. 5,013,699 to reduce the Na 2 O content of the starting composition to less than 3.0 weight percent to provide an ammonium exchanged composition. Contacting the ammonium exchanged composition with rare earth cations under ion exchange conditions as described hereinabove to provide a rare earth exchanged composition. Hydrothermally steaming the low cerium rare earth exchanged composition at a temperature of from about 550° C. to about 850° C. to reduce the unit cell dimension of the crystal lattice and provide a steam calcined, rare earth exchanged zeolite LZ-210 having a Si/Al 2 ratio in the range of 6.5 to 20. It was discovered that adsorbents prepared in the above described manner had surprisingly superior adsorption properties for the adsorption of halogenated hydrocarbons, such as CFC's, HCFC's, HFC's, and water, combined with surprisingly low desorption temperatures for the desorption of these materials. U.S. Pat. Nos. 4,503,023 and 5,013,699 are hereby incorporated by reference.
Other adsorbents in the faujasite family which have a Si/Al 2 ratio within a range of about 3 to about 20 and have water and oxygen adsorption values similar to the hereinabove described LZ-210 material are BSS and ECR-32. The structure of BSS, often referred to as `hexagonal faujasite` is described in Breck, ibid., at pages 55-58, and the direct synthesis of BSS is disclosed in U.S. Pat. No. 5,273,945 as example 1 in Column 7, and is herein incorporated by reference. ECR-32 is a `cubic variant` of the faujasite structure having a Si/Al 2 ratio of at least 6 and containing tetrapropyl and/or tetrabutyl ammonium cations in its super cages as described in European Patent Office publication No. 320114 A on Jun. 14, 1989. The synthesis of ECR-32 is based on the preparation of a gel having the following molar formula:
17.7 SiO.sub.2 : 1 Al.sub.2 O.sub.3 : 4.2 (R).sub.2 O: 1.25 Na.sub.2 O: 295 H.sub.2 O
wherein R is the tetrapropyl (TPA) and/or tetrabutyl ammonium cation. The gel is prepared by adding a sodium aluminate solution containing sodium hydroxide, sodium aluminate, and aluminum sulfate, to a sodium silicate solution, containing a colloidal silica source(40% silica), TPA(OH), and zeolite-forming alumino-silicate seeds according to the procedure disclosed in U.S. Pat. No. 4,340,573 and EPO publication 320114A, which are hereby incorporated by reference. The gel is maintained at a temperature of about 100° C. for a period of about 10 days to crystallize. The resulting crystals are filtered, washed, and calcined for about 2 hours in air at a temperature of between about 400° C. and about 600° C. Both the BSS and the ECR-32 may under go the further steps of rare earth exchange and calcination as described hereinabove.
For purposes of the present invention it is required that the solid adsorbent be agglomerated with a binder. Although there are a variety of synthetic and naturally occurring binder materials available such as metal oxides, clays, silicas, aluminas, silica-aluminas, silica-zirconias, silica-thorias, silica-berylias, silica-titanias, silica-alumina- thorias, silica-alumina-zirconias, mixtures of these and the like, clay type binders are preferred. Examples of clays which may be employed to agglomerate the zeolites without substantially altering the adsorptive properties of the zeolite are attapulgite, kaolin, volclay, sepiolite, halloysite, palygorskite, kaolinite, bentonite, montmorillonite, illite and chlorite.
DETAILED DESCRIPTION OF THE DRAWINGS
The further description of the method of this invention is presented with reference to the attached schematics, FIGS. 1 and FIG. 2. The figures represent preferred arrangements of the invention and are not intended to be a limitation on the generally broad scope of the invention as set forth in the claims. Of necessity, some miscellaneous appurtenances including valves, pumps, separators, heat exchangers, and etc. have been eliminated. Only those vessels and lines necessary for complete and clear understanding of the process of the present invention are illustrated.
Referring to FIG. 1, a schematic diagram of an apparatus for purifying refrigerant according to the process of the instant invention is illustrated. The operation of the process as shown in FIG. 1 is based on an 8-valve design. The apparatus can be employed in a continuous or periodic operation for purifying refrigerant. A contaminated refrigerant gas stream is withdrawn from a refrigeration system and is passed in line 1 through valve V-8, line 2, line 3, valve V-1 and lines 4 and 5 to a first adsorption zone 24. Adsorption zone 24 is filled with an adsorbent selective for the adsorption of the refrigerant. Adsorption zone 24 is operated at ambient conditions such as an adsorption temperature ranging from -15° C. to about 40° C. and about atmospheric pressure and contains a heat exchange coil 25 for use during desorption at a desorption temperature ranging from 30° C. to about 250° C. The contaminated refrigerant enters the adsorption zone 24 and forms a mass transfer zone which travels through the first adsorption zone in the direction of the feed flow. An adsorption effluent is withdrawn from adsorption zone 24 in line 6 and passed via line 7, valve V-5, line 12 and line 13 to a second adsorption zone 26, connected in series with the first adsorption zone. A second adsorption effluent comprising impurities is withdrawn from the second adsorption zone 26 in line 20 and passed through lines 21, valve V-4, line 11 and line 10. In this manner, impurities such as water, air and other gases are vented from the process. The process continues in this adsorption mode until the mass transfer zone of the refrigerant has traveled through adsorption zone 24 and has progressed into adsorption zone 26. At this point in the process, essentially no impurities or contaminants remain in adsorption zone 24. The flow of the contaminated refrigerant through valve V-8 is terminated and the regeneration of adsorption zone 24 with the recovery of purified refrigerant therefrom is begun while adsorption zone 26 is isolated. Valve V-8 is closed and valves V4 and V-5 are closed, and valve V-7 is opened. Heat from an external source, such as hot water, steam or electric power is applied to the heat exchange coil 25 to heat adsorption zone 24 to the desorption temperature. Heating adsorption zone 24 results in the desorption of the previously adsorbed refrigerant from the selective adsorbent, and the desorbed refrigerant evolved therefrom passes through lines 5 and 4, valve V-1, line 3, line 29, line 17, valve V-7, line 18, vacuum pump 28 and line 19. From line 19 the purified refrigerant having had the impurities removed may now be returned to the refrigeration device from which the contaminated refrigerant was removed. Vacuum pump 28 shown in FIG. 1 may be an external vacuum pump for returning the purified refrigerant to the refrigeration system, or may be the compressor within the refrigeration system. In some installations additional filtration equipment (not shown) may be employed to filter mineral and organic acids and sludge from the refrigerant stream at a point before the purified refrigerant is returned to the refrigeration system, or before the contaminated refrigerant enters the first adsorption zone. At the completion of this desorption step, the second adsorption zone 26 may now be activated as the lead bed by closing valve V-7, valve V-5, valve V-4 and valve V-1. Both heater 25 and heater 27 are off. Contaminated refrigerant flows from line 1 through valve V-8, lines 2, 29, 16, and 15, valve V-2, lines 14 and 13 to adsorbent bed 26. An intermediate effluent stream is withdrawn from the adsorption zone 26 via line 20 and passed through line 22, valve V-6, line 23 and line 5 to the fully regenerated bed 24, now in the trim position. The impurities are withdrawn at essentially atmospheric pressure from adsorption zone 24 through lines 6, 8, valve V-3, line 9 and line 10. This lead/trim operation continues until the mass transfer zone of the refrigerant moves from adsorption zone 26 into adsorption zone 24. At this point in the process, adsorption zone 24 is placed on standby and adsorption zone 26 under goes regeneration in a manner similar to that described herein above for adsorption zone 24. Valve V-2 and valve V-7 are open while all other valves are closed, and heater 27 is activated to provide heat for the desorption of refrigerant from adsorption zone 26. Desorbed, purified refrigerant passes from adsorption zone 26 through lines 13, 14, valve 2, line 15, line 16, line 17, valve V-7, line 18, vacuum pump 28, and line 19 to be returned to the refrigeration system.
Referring to FIG. 2, an alternate arrangement of the invention is described. The description hereinbefore presented with reference to FIG. 1 is applicable here unless otherwise set forth below. In the arrangement of FIG. 2, there are 9 valves labeled L-1 through L-9. As in FIG. 1, there are two adsorption beds (bed 53 and bed 54) and two heater means (55 with respect to adsorption zone 53 and heater means 56 with respect to adsorption zone 54). The heater means may employ heated water, steam, or electricity in the form of coils or elements placed in contact with the adsorbent in the adsorption zones. In the operation of the scheme depicted in FIG. 2, initially valve L-1, L-4, L-6, and L-7 are open while all other valves are closed, and the heaters 55 and 56 are in the off position. Contaminant refrigerant enters the process via line 30, line 31, valve L-1, lines 32 and 34 and flows to adsorption zone 53. An intermediate effluent 35 is withdrawn from adsorption zone 53 and passed via line 35, line 37, Valve L-7, lines 41, 42, and 45, Valve L-6, line 46 and line 47 to the feed end of adsorption zone 54. Impurities materials and contaminants are withdrawn as an effluent from adsorption zone 54 in lines 48 and 49, and passed through valve L-4 to lines 40 and 39 where they are vented to the atmosphere. This lead/trim adsorption operation continues until the mass transfer zone of refrigerant passes through adsorption bed 53 into adsorption bed 54 to a point such that only purified refrigerant remains adsorbed on the selective adsorbent within the lead adsorption zone 53. At this point, the valves L-5 and L-9 are open and all other valves are closed and heater 55 raises adsorption zone 53 to the desorption temperature while adsorption zone 54 is isolated. Purified regenerant gas evolves from the desorption of the regenerant in adsorption zone 53 at a desorption pressure at or below atmospheric pressure as heat is applied from heater means 55, allowing purified refrigerant gas to pass through lines 34, 33, valve L-5, line 43, line 44, valve L-9, line 57 to vacuum pump 60 and line 58 to be returned to the refrigeration system. This regeneration of adsorption zone 53 continues until no more refrigerant is evolved. Vacuum pump 60 can again be a separate compression device or it can, optionally, be a compression device within the refrigeration system itself. At the completion of the regeneration of adsorption zone 53, adsorption zone 54 now becomes the lead adsorption zone and regenerated adsorption zone 53 becomes the trim adsorption zone. Valves L-1, L4, L-6, L-7 and L-9 are now closed and valves L-2, L-3, L-5 and L-8 are open while both the heater means 55 and 56 are not operated. Contaminated refrigerant flows from line 30 to lines 52, valve L-2, line 50, and line 47 to adsorption zone 54. An intermediate stream is withdrawn from adsorption zone 54 in line 48 and passed via lines 62, valve L-8, line 61, line 42, line 43, valve L-5, line 33 and line 34 to adsorption zone 53. The impurities in a second effluent stream are withdrawn via line 35 and passed through line 36, valve L-3, line 38 and line 39 to be vented to the atmosphere. This arrangement continues until the mass transfer zone of the refrigerant from adsorption zone 54 passes into adsorption zone 53. At that point, the adsorption zone 53 is placed in standby and adsorption zone 54 undergoes regeneration by the closing of valves L-1 through L-5 and L-7 and L-8, opening valves L-6 and L-9, and activating the heater means 56. Purified refrigerant gas is evolved in adsorption zone 54, passed through line 47, line 46, valve L-6, line 45, line 44 valve L-9, line 57 to vacuum pump 60 and returned to the refrigeration system via line 58.
The invention as depicted in FIG. 1 or FIG. 2 may be employed to purge non-condensable gases such as air from refrigerant recovery and recycle machines. Such machines typically contain filter driers, oil separators, and have a refrigerant recovery tank containing contaminated refrigerant recovered from other refrigeration systems. These systems also contain a refrigerant storage tank containing purified refrigerant. The process of the instant invention may be used to withdraw contaminated refrigerant from the refrigerant recovery tank and return at least a portion of purified refrigerant, depleted in air and water vapor to the refrigerant recovery tank. In another embodiment, a portion of the purified refrigerant from the instant process may be passed to the refrigerant storage tank.
The invention will be further clarified by a consideration of the following examples, which are intended to be purely exemplary of the use of the invention.
EXAMPLES
Example I
The refrigerant adsorption screening tests were conducted in a modified BET absorption apparatus. The apparatus measures adsorption by sensing changes in pressure and temperature inside a reference volume which is attached to an adsorption vessel containing the adsorbent sample. The adsorbent sample was maintained at a steady temperature by the action of a temperature controlled bath. The reference volume can be isolated from the adsorbent vessel by means of an isolation valve. The reference volume may also be connected or isolated from a vapor source by means of another isolation valve, and finally the absolute pressure of the reference volume may be controlled by means of a high vacuum pump which is also connected to the reference volume by means of a third isolation valve. Adsorption measurements were made by first evacuating the reference volume and the adsorbent sample vessel to a pressure of approximately 5×10 -6 torr while heating the adsorbent and adsorbent vessel to an activation temperature of approximately 200° C. The temperature of activation was controlled and monitored. The activation was considered complete after the pressure of the system was dropped to 5×10 -6 torr. (generally, about 16 hours). After activation, the sample was isolated from the reference volume and the evacuation pump and was cooled to room temperature. The reference volume also evacuated to 5×10 -6 torr was also isolated from the vacuum pump and was charged to a vapor pressure of about 5 torr with pure refrigerant vapor. The pressure of refrigerant was monitored by an MKS Baratron Pressure Transducer. Once stable readings were obtained on both the pressure and temperature within the reference volume, the isolation valve separating the adsorbent sample from the reference volume was opened and the pressure and temperature of the system were monitored until they stabilized, i.e., changing no more than by 1 part in 10 6 within one minute. Refrigerant isotherms were obtained by repeating the isolation, charging and equilibration of the reference volume with the adsorbent vessel until a pre-determined loading level or pressure level were obtained. Refrigerant loadings on an adsorbent sample of a rare earth exchanged zeolite LZ-210 with a SiO 2 /Al 2 O 3 ratio of less than about 12 and silicalite. The isotherms of the refrigerant for the adsorbent were determined at 25° C. and shown in FIG. 3. Surprisingly, the rare earth exchanged zeolite LZ-210 over the range of 100 to about 600 kPa showed an adsorption of R-22 refrigerant in the range of about 30 to about 48 wt % compared to an adsorption of R-22 refrigerant in the range of about 14 to 20 for a silicalite adsorbent. Thus, the low cerium rare earth exchanged LZ-210 showed a better than 2 fold increase in capacity for the R-22 over the silicalite. FIG. 4 shows the performance of the same adsorbent at a temperature of 35° C. At the higher temperature, over a refrigerant pressure from 100 to 600 kPa, the silicalite adsorption capacity ranged from about 12 wt % to about 18 wt %, and the low cerium rare earth exchanged LZ-210 zeolite adsorption capacity ranged from about 25 to about 42, again representing a two fold increase in capacity over the silicalite.
Example II
Samples of low cerium rare earth exchanged zeolite LZ-210 were prepared at a SiO 2 /Al 2 O 3 ratio of 6.5 and 12.0 and a portion of each of the samples were calcined according to normal practice while the remaining portion was in the presence of steam. Adsorption isotherms according to the procedure outlined in Example I were developed for the adsorption of R-22. This isotherm data for R-22 were summarized as a value of Xm for each of the sample adsorbents.
TABLE 1______________________________________ADSORBENT LOADING FOR R-22 @ ABOUT 298° K. ADSORBENT Xm, wt %______________________________________A RE210-6.5C 41.63B RE210-6.5S 46.33C RE210-12.0C 65.67D RE210-12.0S 48.76E Silicalite 18.77______________________________________
The term Xm is the maximum loading level of the adsorbent according to the Langmuir Isotherm Equation (See Adamson, "Physical Chemistry of Surfaces,"4th Edition, John Wiley & Sons, New York, 1982, at p. 521). Adsorbents A and B have a silica to alumina ratio of 6.5 and adsorbents C and D have a silica to alumina ratio of about 12. Adsorbents A and C were calcined, and adsorbents B and D were in the presence of steam (1 wt % ) calcined according to procedures well-known to one skilled in the art. Adsorbent E is a silicalite adsorbent. The Xm results for samples A-D indicates that the R-22 adsorption capacity of these faujasite based samples having SiO 2 /Al 2 O 3 ratios of about 6.5 to about 12 showed a greater than 2 times the adsorption capacity over the silicalite sample.
Example III
Experimental measurements of the speed of the mass transfer front and the length of the breakthrough fronts were developed for refrigerant R-22 and R-12 on a silicalite adsorbent. A cylinder with an inside diameter of about 5 cm (2 inches) and 30.48 cm (12 inches) in height was filled with silicalite pellets having a nominal 1.6 mm (1/16 inch) diameter. A refrigerant supply cylinder supplied a flow of refrigerant gas to the cylinder at a flow rate controlled by a pressure regulator and the pressure of the effluent gas from the cylinder was monitored by an absolute pressure transducer. Prior to each experiment, the cylinder, loaded with adsorbent, was purged with nitrogen until no trace of refrigerant vapor was present. The concentration of refrigerant vapor was measured by a flame ionization detector which was calibrated independently for each refrigerant. Following each nitrogen purge, the absolute pressure in the adsorbent filled cylinder was essentially at atmospheric pressure. Refrigerant vapor was introduced at a controlled rate and the pressure and the concentration of refrigerant of the effluent gas was monitored as a function of time. FIG. 5 illustrates the analytical results for the refrigerant R-22 breakthrough curves at flows ranging from 4 to 16 standard liters per minute (SLPM) as measured at 0° C. and 1 atmosphere. FIG. 6 shows the analytical results of the breakthrough curves for refrigerant R-12 at 4, 8, and 16 SLPM. The total pressure of the refrigerant in both determinations was controlled at about 150 kPa (22 psia) and both series were developed at a room temperature of about 25° C. The sharp nature of the mass transfer zone for the refrigerants over the adsorbent indicated that essentially all of the unadsorbed nitrogen, or inert gas, would be pushed out of a first adsorption bed when the mass transfer zone is passed through the first adsorption bed and into a second adsorption bed. The capacity of an adsorption bed at the point when the stoichiometric point of the mass transfer front reaches the end of the bed is by definition the equilibrium capacity of the adsorbent in the adsorption bed. The mass transfer front lengths were determined as a function of the refrigerant gas feed velocity from the breakthrough curves for each refrigerant and shown in FIG. 7 for R-22 and FIG. 8 for R-12. These figures indicate that the front length is a relatively linear function of the gas feed velocity and that for velocities in the range of about 1 to about 10 cm/second, and the results confirm a relatively sharp mass transfer zone wherein following the passing of the mass transfer zone from an adsorbent bed, the material remaining in the adsorbent bed will be essentially all refrigerant. The adsorbents of Example I which demonstrated similarly shaped adsorption isotherms for refrigerants R-22 and R-12 with at least twice the capacity for the adsorption of the refrigerants as silicalite will have a similarly sharp mass transfer zone. The sharp mass transfer profile and relatively short mass transfer length permits a surprisingly large portion of the adsorption bed to be employed for refrigerant capacity with a relatively small portion of the bed reserved for the mass transfer zone. This permits the trim bed to be used with more than one lead bed for refrigerant collection applications.
Example IV
Samples of the BSS and ECR-32 materials were prepared according to the synthesis methods disclosed in U.S. Pat. No. 5,273,945 for BSS and European Patent Office Publication 320114 A for ECR-32, and compared to low cerium rare earth exchanged LZ-210 and Zeolite Y-64, the starting material for producing LZ-210. The results of the analysis are shown in Table 2. The unit cell sizes, Ao are shown for each of the materials tested. The BSS material has a hexagonal structure wherein the a and b dimensions are equal. The silica to alumina ratio of the materials tested ranged from about 5 to about 12. The oxygen adsorption, expressed in weight percent was measured at 100 torr and -183° C. The oxygen adsorption capacities of the BSS and ECR-32 were similar to the Y-64 and the rare earth exchanged and steam calcined LZ-210. The capacity for the adsorption of water was measured at 4.6 torr and about 25° C. The similar silica to alumina ratios and the similar water and oxygen adsorption capacities of the BSS and ECR-32 indicate a similar affinity for the adsorption of refrigerants shown by the low cerium rare earth exchanged LZ-210 zeolites of Example I.
TABLE 2______________________________________COMPARATIVE ADSORBENT PHYSICAL PROPERTIES Y-64 RE LZ-210 BSS ECR-32______________________________________Ao (a) 24.711 24.58 17.36 24.506(c) 28.45Si/Al.sub.2 5.13 6.3 7.14 8.82O.sub.2, wt-% 35.72 34.8 32.06 36.4H.sub.2 O, wt-% 35 28 33.7 31.4______________________________________
Other embodiments of the invention will be apparent to the skilled in the art from a consideration of this specification or practice of the invention disclosed herein. It is intended that the specification and the examples be considered exemplary only, with the true scope and spirit of the invention being indicated by the following claims. | A process and apparatus for the recovery and purification of a contaminated refrigerant withdrawn from a refrigeration or refrigerant recovery system which employs a compressor and an adsorbent selective for the adsorption of halogenated hydrocarbons. The adsorbent is selected from the group consisting of silicalite, faujasites, steamed and rare earth exchanged zeolite Y, mordenite, ZSM-5 and mixtures thereof, and more particularly the group consisting of a low cerium rare earth exchanged zeolite Y-84, a low cerium rare earth exchanged zeolite LZ-210, Breck Structure Six, ECR-32, and mixtures thereof. A significant increase in the capacity of these adsorbents over conventional adsorbents combined with the use of novel process steps to recover, purify and return a purified refrigerant to the refrigeration system result in significant cost savings at reduced risk of release of halogenated hydrocarbons to the environment. | 8 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to a switch device for starting and stopping the rotation of a DC electric motor for opening and closing a window of a motor vehicle such as an automobile or for a similar purpose and more particularly to such a switch device for a DC electric motor operating at a high source voltage (such as 42V).
[0002] Automobiles currently make use of a 14V electrical system with source voltage of 12V. Since an increased number of electronic devices are being carried on automobiles, however, a 14V system is sometimes hardly capable of supplying sufficient power. As a result of global discussions in consortia representing both universities and industries in view of this problem, a consensus has been obtained from the point of view of safety to human bodies to adopt a voltage system that is three times higher, or a 42V system with source voltage of 36V. Examples of electrical equipment to be operated in a 42V electrical system include DC motors contained in a door for opening and closing a window (or so-called DC motors for operating a power window).
[0003] [0003]FIGS. 10A and 10B are respectively a structural diagram and a circuit diagram of a prior art switch device 1 for rotating (both in positive and negative directions) and stopping such a DC motor 2 for operating a power window. Such a switch device may typically be installed inside the elbow rest attached to the front or back seat of the vehicle or inside a door. FIGS. 10A and 10B show the switch device 1 when the DC motor 2 is stopped, that is, when a knob 3 therefor is not being operated. In what follows, this condition is referred to as the neutral condition.
[0004] The knob 3 is attached to a case 4 on a door such that it can be tilted by a specified angle both in clockwise and counter-clockwise directions, as shown in FIG. 10A. If the knob 3 is rotated in the clockwise direction, the window is closed (to be in the UP condition). If the knob 3 is rotated in the counter-clockwise direction, the window is opened (to be in the DOWN condition). If the force applied on the knob 3 is released, or if the finger is lifted therefrom, the knob 3 returns to its neutral position by the operations of a spring 5 and a plunger 6 buried inside the knob 3 and thereafter remains in this neutral condition.
[0005] The knob 3 has a downward protrusion 7 which is at a position as shown in FIG. 10A when the knob 3 is in the neutral position but swings to the left when the knob 3 is in the UP condition as shown in FIG. 12A and to the right when the knob 3 is in the DOWN condition (not shown in drawing).
[0006] Provided inside the case 4 is a switch unit 9 mounted to a printed circuit board 8 so as to function as a two-circuit two-contact switch of a momentary type. FIG. 11 shows an external view of this switch unit 9 , comprising a housing 10 , two common terminals 11 and 12 coming out of one side surface of the housing 10 , one normally open terminal 13 coming out of the other side surface of the housing 10 and two normally closed terminals 14 and 15 coming out of the bottom surface of the housing 10 . These terminals 11 - 15 are soldered to specified conductor circuits on the printed circuit board 8 so as to be connected to a power source line (or the +B line) 17 , a grounding line 18 and the DC motor 2 , as shown in FIG. 10B.
[0007] As shown in FIG. 10B, the switch unit 9 includes two switch mechanisms A and B adapted to operate mutually exclusively according to the position of a slider 28 on the upper surface of the switch unit 9 . In the above, to be switched mutually exclusively means opening only the normally closed (NC) contact of either one of the switch mechanisms A and B, or closing only the normally open (NO) contact of that switch mechanism.
[0008] Explained more in detail, when the slider 28 is in the neutral condition, as shown in FIG. 10A, it is in the closed condition between the moving contact 19 and the NC contact 23 of the first switch mechanism A and between the moving contact 20 and the NC contact 24 of the second switch mechanism B. In this position, the NO contacts 21 and 22 of both switch mechanisms A and B are in open condition and the NC contacts 23 and 24 of both switch mechanisms A and B are in closed condition, as their names (NO and NC) indicate. If the slider 28 is moved to the left as indicated by arrow L in FIG. 11 to be in the UP condition, the closed condition between the moving contact 20 and the NC contact 24 of the second switch mechanism B is maintained but the NC contact 23 of the first switch mechanism A is released from the closed condition and a new closed condition is established between the moving contact 19 and the NO contact 21 . Likewise, if the slider 28 is moved to the right as indicated by arrow R in FIG. 11 to be in the DOWN condition, the closed condition between the moving contact 19 and the NC contact 23 of the first switch mechanism A is maintained but the NC contact 24 of the second switch mechanism B is released from the closed condition and a new closed condition is established between the moving contact 20 and the NO contact 22 .
[0009] The switching operations as described above are made possible by the movement of the slider 28 as well as by the designed shape of the bottom surface of the slider 28 . FIGS. 11C and 11D are sectional views of the slider 28 taken respectively along lines 11 C- 11 C and 11 D and 11 D of FIG. 1B. FIG. 1C shows that the right-hand half of the slider 28 is made thicker and FIG. 11D shows that the left-hand half of the slider 28 is made thicker. As will be explained below, the switching mechanisms A and B are switched in a mutually exclusive manner according to the positional relationship between these thickly made portions of the slider 28 . It is to be noted that only one of the common terminals 11 and 12 and one of the normally closed terminals 14 and 15 are visible in FIG. 10A because the others of the common terminals and the normally closed terminals are hidden behind the front ones.
[0010] As explained above, the switch unit 9 described above functions as a two-circuit two-contact switch of a momentary type. This comes about because the moving contacts 19 and 20 , the NO contacts 21 and 22 and the NC contacts 23 and 24 are connected respectively to the common terminals 11 and 12 , the normally open terminal 13 and the normally closed terminals 14 and 15 such that the switching of contacts in two circuits (that is, the switching between the NO contact 21 and the NC contact 23 by the moving contact 19 and the switching between the NO contact 22 and the NC contact 24 by the moving contact 20 ) can be effected in a mutually exclusive manner.
[0011] The moving contacts 19 and 20 are attached at the tips of a mobile pieces 25 and 26 each in the form of a metallic spring plate, and these mobile pieces 25 and 26 are biased downwardly with reference to FIG. 10A by means of push buttons 27 A (for the first switch mechanism A) and 27 B (for the second switch mechanism B). These push buttons 27 A and 27 B are in contact with the bottom surface of the slider 28 and are individually pushed downward if the slider 28 is moved to the left as shown in FIG. 12A according to the contour (or the position of the thick portions) of the slider 28 . The slider 28 has an upward protrusion 29 that engages with the tip of the downward protrusion 7 of the knob 3 and slides in the left-right direction according to the movement of the knob 3 into the UP and DOWN conditions.
[0012] In other words, as the knob 13 of this switch device 1 is raised into the UP condition, the slider 28 slides to the left and the push button 27 A in contact with its thick portion along line 11 C- 11 C is pushed downward, thereby establishing an open condition between the moving contact 19 and the NC contact 23 of the first switch mechanism A while maintaining a closed condition between the moving contact 19 and the NO contact 21 .
[0013] If the finger is released from the knob 3 to set it in its neutral condition, the slider 28 slides to the right to return to its original position, causing the push button 27 A to move upward and the moving contact 19 and the NC contact 23 of the first switch mechanism A to be in the closed condition.
[0014] If the knob 3 is pushed down to set it in the DOWN condition, the slider 28 slides to the right and the push button 27 B in contact with its thick portion along line 11 D- 11 D is pushed downward, thereby establishing an open condition between the moving contact 20 and the NC contact 24 of the second switch mechanism B while maintaining a closed condition between the moving contact 20 and the NO contact 22 . If the finger is released from the knob 3 thereafter to set it in its neutral condition, the slider 28 slides to the left to its original position, causing the push button 27 B to move upward and the moving contact 20 and the NC contact 24 of the second switch mechanism B to be in the closed condition.
[0015] When the knob 3 is in the neutral condition, the contacts of the first and second switch mechanisms A and B are in conditions as shown in FIG. 10B, that is, the moving contact 19 and the NC contact 23 of the first switch mechanism A are in the closed condition and the moving contact 20 and the NC contact 24 of the second switch mechanism B are in the closed condition. Under this condition, the DC motor 2 is not connected to the +B line 17 and hence the DC motor 2 does not rotate.
[0016] When the knob 3 is in the UP condition, the contacts of the first and second switch mechanisms A and B are in conditions as shown in FIG. 12B, that is, the moving contact 19 and the NO contact 21 of the first mechanism A are in the closed condition and the moving contact 20 and the NC contact 24 of the second switch mechanism B are in the closed condition. Under this condition, a closed circuit is formed from the +B line 17 to the DC motor 2 to the grounding line 18 , and the DC motor 2 rotates in the direction of closing the window.
[0017] If the knob 3 is in the DOWN condition, although not shown, the moving contact 19 and the NC contact 23 of the first switch mechanism A are closed and the moving contact 20 and the NO contact 22 of the second switch mechanism B are closed. Under this condition, a closed circuit is formed from the grounding line 18 to the DC motor 2 to the +B line 17 , and the DC motor 2 rotates in the direction of opening the window.
[0018] Although an example has been explained wherein the rotation of a DC motor is controlled by a single switch unit, there are also switch devices, depending on the kind of automobiles, allowing the window on the rider's side or the back windows to be controlled from the driver's seat. FIG. 13 shows a circuit structure for such a switch device, structured as a combination of a switch unit 9 for the driver and another switch unit 9 ′ for the rider such that the DC motor 2 for the window on the rider's side can be rotated or stopped not only by the rider but also by the driver.
[0019] Although an example was described above wherein a single terminal is assigned to each of the moving contacts 19 and 20 and the NC contacts 23 and 24 (that is, the common terminals 11 and 12 and the normally closed terminals 14 and 15 ) and a single normally open terminal 13 is assigned to both NO contacts 21 and 22 such that there are altogether five terminals, there are examples of other types such as shown in FIG. 14. The example shown in FIG. 14 is characterized wherein contacts connected to the grounding line 18 (the NC contacts 23 and 24 of the first and second switch mechanisms A and B) are connected together inside the unit and then pulled out from a single terminal 15 a to be connected to the grounding line 18 such that there are altogether four terminals. Alternatively, two switch mechanisms each with one circuit may be used. In such a case, there are six terminals altogether.
[0020] Examples of prior art switch system described above with reference to FIGS. 10 - 14 may all be used without any trouble as long as they are used with a conventional 14V electrical system. If such a prior art switch system is used with a 42V electrical system, however, an overly strong current will flow between a specified pair of contacts at the return time from the UP condition to the neutral condition or from the DOWN condition to the neutral condition, thereby damaging these contacts.
[0021] [0021]FIG. 15 shows how such a damage may come about, FIG. 15A showing the switch device in the UP condition, FIG. 15B showing it at a moment immediately before its return to the neutral condition, and FIG. 15C showing when the switch device has returned to the neutral condition. They are different from the diagrams explaining the prior art operations in that a higher voltage (the source voltage of a 42V electrical system being 36V) is being applied to the +B line 17 .
[0022] When the mechanism is in the UP condition as shown in FIG. 15A, the NO contact 21 and the moving contact 19 of the first switch mechanism A are in the closed condition and the moving contact 20 and the NC contact 24 of the second switch mechanism B are similarly in the closed condition. As a result, a closed circuit is formed from the +B line 17 to the DC motor 2 to the grounding line 18 and the DC motor 2 rotates in the direction of closing the window. When the driver's finger is released from the knob 3 , the NO contact 21 and the moving contact 19 of the first switch mechanism A are released from their closed condition and the moving contact 19 begins to move towards the NC contact 23 while generating small arc discharges between the NO contact 21 within an allowable range until finally the moving contact 19 and the NC contact 23 of the first switch mechanism A come to be in the closed condition as shown in FIG. 15C. The source voltage then ceases to be supplied to the DC motor 2 and the rotation of the DC motor 2 stops.
[0023] In the case of a prior art switch device, the contact gap is as small as about 0.5 mm and hence cannot support an arc discharge voltage of about 42V. Thus, the moving contact 19 is in the condition of having a voltage of several volts applied thereto when it becomes connected to the NC contact 23 . By experiments carried out by the present inventors, it was discovered that a large current of over 100A will flow from the moving contact 19 to the grounding line 18 through the NC contact 23 over a very short period of time such as about 0.5 ms (as indicated by a thick arrow 31 in FIG. 15C and that this results in a large discharge (indicated by numeral 32 ) between the NO contact 21 and the NC contact 23 , thereby damaging or destroying the moving contact 19 and the NC contact 23 .
[0024] Since this phenomenon will impede the popular acceptance of 42V electrical systems, its elimination has been a technical problem to be solved as quickly as possible.
[0025] In general, the gap between contacts is made wider as the applied voltage is increased in order to prevent arc discharges. If the gap is increased to about 4 mm, the arc discharge voltage may be accordingly increased and the moving contact 19 can be connected to the NC contact 23 while no voltage is applied thereon. If the gap is thus increased, however, the switch unit as a whole becomes large and may be inconvenient for being used on a vehicle.
SUMMARY OF THE INVENTION
[0026] It is therefore an object of this invention to provide a switch device which will not cause the switch unit to become large when applied to a 42V electrical system, while being able to prevent damages to the contacts and causing no increase in the time lag in switching between contacts.
[0027] A switch device according to a first embodiment of this invention for rotating and stopping a DC motor may be characterized as comprising a first switch element, a second switch element and an operating element, the first switch element having two moving contacts, two normally open NO contacts and two normally closed NC contacts, the second switch element having at least one (say, one or two) normally closed NC contact, and the operating element serving to make connections in specified manners such as connecting the two moving contacts of the first switch element individually to input terminals of the DC motor, connecting the two NO contacts to a voltage source line (“the higher voltage source line), and connecting each of the two NC contacts of the first switch element to another voltage source line (“the lower voltage source line”) at a lower voltage than the higher voltage source line each through one of the at least one NC contact of the second switch element. The operating element further serves to maintain the aforementioned at least one NC contact of the second switch element in an open condition during a period from when the NO contacts begin to change from a closed condition to an open condition until the NC contacts of the first switch element finish changing from an open condition to a closed condition.
[0028] With a switch device thus structured, the DC motor stops its rotation if the two NC contacts of the first switch element are set in the closed condition because the lower voltage of the lower source line (say, at the ground voltage) is then applied to both of the input terminals of the DC motor through these two NC contacts of the first switch element and the NC contact or contacts of the second switch element. If either one of the two NC contacts of the first switch element alone is set in the closed condition, the DC motor rotates because while the lower voltage source line is connected to one of the input terminals of the DC motor through this closed NC contact of the first switch element and the NC contact of the second switch element (if the second switch element has only one NC contact) or the corresponding one of the NC contacts of the second switch element (if the second switch element has two NC contacts) connected to the closed NC contact of the first switch element, the higher voltage source line is connected to the other of the input terminals of the DC motor through the closed one of the two NO contacts of the first switch element.
[0029] If the closed one of the two NO contacts of the first switch element is returned to its normally open condition while the DC motor is rotating as explained above, the DC motor stops its rotation. In this situation, during the period from the starting moment when the closed NO contact of the first switch element begins to be opened until the corresponding NC contact completes its change from the open condition to the closed position, the corresponding NC contact of the second switch element is maintained in the open condition such that the current route between the NC contacts of the first switch element and the lower voltage source line and hence no large instantaneous current can be generated and damage to the contacts of the first switch element can be prevented.
[0030] A switch device according to a second embodiment of the invention is similar to the one according to the first embodiment described above except that the operating element serves to connect the two NC contacts of the first switch element to the lower voltage source line and each of the two NO contacts of the first switch element to the higher voltage source through the NC contact or one of the NC contacts of the second switch element. Moreover, before either one of the NO contacts of the first switch element changes from a closed condition to an open condition, the operating element allows the normally closed NC contact of the second switch element connected to the opened NO contact to be in an open condition.
[0031] With a switch device thus structured, the DC motor stops its rotation if the two NC contacts of the first switch element are set in the closed condition because the lower voltage source line is then connected to both of the input terminals of the DC motor through these two NC contacts of the first switch element. If either one of the two NC contacts of the first switch element alone is set in the closed condition, the DC motor rotates because while the lower voltage source line is connected to one of the input terminals of the DC motor through this closed NC contact of the first switch element, the higher voltage source line is connected to the other of the input terminals of the DC motor through the closed one of the two NO contacts of the first switch element and the NC contact of the second switch element (if the second switch element has only one NC contact) or the corresponding one of the NC contacts of the second switch element (if the second switch element has two NC contacts) connected to the closed NC contact of the first switch element.
[0032] If the closed one of the two NO contacts of the first switch element is returned to its normally open condition while the DC motor is rotating as explained above, the DC motor stops its rotation. In this situation, before the closed one of the NO contacts of the first switch element changes from a closed condition to an open condition, the corresponding NC contact of the second switch element is allowed (say, by a manual operation) to be in an open condition such that the current route between the NO contacts of the first switch element and the higher voltage source line and hence no large instantaneous current can be generated and damage to the contacts of the first switch element can be prevented.
[0033] A switch device according to a third embodiment of this invention may be characterized also as comprising a first switch element, a second element and an operating element. The first element has two normally open NO contacts and the second switch element has two normally closed NC contacts. The operating element serves to connect the two input terminals of a DC motor to the higher voltage line each through a corresponding one of the two NO contacts of the first switch element and the two input terminals of the DC motor to the lower voltage source line through a corresponding one of the two NC contacts of the second switch element. Before either one of the NO contacts of the first switch element changes from an open condition to a closed condition, the operating element allows the NC contact of the second switch element connected to the closed NO contact to be in an open condition.
[0034] With a switch device thus structured, the DC motor stops its rotation if the two NO contacts of the first switch element are set in the open condition and the two NC contacts of the second switch element are set in the closed condition because the lower voltage source line is then connected to both of the input terminals of the DC motor through the two NC contacts of the second switch element. If either one of the two NO contacts of the first switch element alone is set in the closed condition and the NC contact of the second switch element connected to the corresponding NC contact is opened, the DC motor rotates because while the lower voltage source line is connected to one of the input terminals of the DC motor through these closed contacts, the higher voltage source line is connected to the other of the input terminals of the DC motor.
[0035] If the closed one of the two NO contacts of the first switch element is returned to its normally open condition while the DC motor is rotating as explained above and the corresponding NC contact of the second switch element is returned to its closed condition, the DC motor stops its rotation. In this situation, before the closed one of the NO contacts of the first switch element changes from a closed condition to an open condition, the corresponding NC contact of the second switch element is allowed to be returned to the closed condition such that the NO contacts of the first switch element can support a sufficiently large voltage for an arc discharge and the generation of a large instantaneous current can be prevented although the NC contact connected to this NO contact of the first switch element becomes closed and hence damage to the contacts of the first switch element can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] [0036]FIG. 1 is a structural diagram of a switch device embodying this invention.
[0037] [0037]FIG. 2 is a plan view of a slider as the operating element of the switch device of FIG. 1.
[0038] [0038]FIG. 3 is a diagram for showing the operation of one of switch groups.
[0039] [0039]FIGS. 4A, 4B, 4 C and 4 D, together referred to as FIG. 4, are circuit diagrams of a system for rotating in both positive and negative directions and stopping a DC motor for opening and closing a window by incorporating the switch device of FIG. 1.
[0040] FIGS. 5 - 8 are circuit diagrams of various embodiments of this invention.
[0041] [0041]FIG. 9 is an external view of an embodiment wherein the first and second switch elements are formed as separate units.
[0042] [0042]FIGS. 10A and 10B, together referred to as FIG. 10, are respectively a structural diagram and a circuit diagram of a prior art switch device when it is in the neutral condition.
[0043] [0043]FIGS. 11A, 11B, 11 C and 11 D, together referred to as FIG. 11, are respectively an external view of the switch unit of FIG. 10, a plan view of its slider, a sectional view taken along line 11 C- 11 C of FIG. 11B and a sectional view taken along line 11 D- 11 D of FIG. 11B.
[0044] [0044]FIGS. 12A and 12B, together referred to as FIG. 12 are respectively a structural diagram and a circuit diagram of the prior art switch device of FIG. 10 when it is in the UP condition.
[0045] [0045]FIG. 13 is a circuit diagram of another prior art switch device.
[0046] [0046]FIG. 14 is a circuit diagram of still another prior art switch device having a total of four terminals.
[0047] [0047]FIGS. 15A, 15B and 15 C, together referred to as FIG. 15, are circuit diagrams for explaining how contacts of a switch device may be damaged.
[0048] Throughout herein, components that are equivalent or at least similar may be indicated by the same symbols and may not necessarily be explained or described in a repetitious manner.
DETAILED DESCRIPTION OF THE INVENTION
[0049] The invention is described next by way of examples. FIG. 1 shows a switch device 40 according to a first embodiment of this invention, which may be roughly characterized as comprising two switch elements (the first switch element 41 and the second switch element 42 ) and an operating element 43 for carrying out the switching operations of these two switch elements 41 and 42 .
[0050] Next, each of these elements will be described individually. The first switch element 41 is comprised of six fixed electrodes 41 a - 41 f each made of a planar metallic conductor inserted inside a molded base (not shown) or formed as a thin film and two mobile members 41 g and 41 h . The metallic material for these six fixed electrodes has a high electrical conductivity and is strong against wears such as copper, bronze and alloys of copper and iron. These six fixed electrodes are arranged in two group of three each, the first group consisting of electrodes 41 a , 41 b and 41 c and the second group consisting of electrodes 41 d , 41 e and 41 f . The two groups of fixed electrodes are arranged parallel to each other, as shown in FIG. 1.
[0051] Let D 41 a , D 41 b , D 41 c , D 41 d , D 41 e and D 41 f denote respectively the surface areas of the fixed electrodes 41 a , 41 b , 41 c , 41 d , 41 e and 41 f . Then, they are related as follows: D 41 a =D 41 d , D 41 b =D 41 e and D 41 c =D 41 f . The fixed electrodes 41 a , 41 b and 41 c of the first group are arranged in this order in the direction shown by line 44 from right to left with reference to FIG. 1. The fixed electrodes 41 d , 41 e and 41 f of the second group are arranged in this order along the same line from left to right with reference to FIG. 1. The separation L 1 a between the fixed electrodes 41 a and 41 b is greater than the separation L 2 a between the fixed electrodes 41 b and 41 c . Similarly, the separation L 1 b (=L 1 a ) between the fixed electrodes 41 d and 41 e is greater than the separation L 2 b (=L 2 a ) between the fixed electrodes 41 e and 41 f.
[0052] The mobile members 41 g and 41 h are shaped so as to be slidable in the direction of the line 44 respectively over the first and second groups of the fixed electrodes 41 a - 41 c and 41 d - 41 f . For example, each may have two curved downward protrusions (the mobile member 41 g having protrusions 41 g 1 and 41 g 2 , and the mobile member 41 h having protrusions 41 h 1 and 41 h 2 ). Each may be made of a metallic material such as copper, bronze and alloys of copper and iron with a high electrical conductivity and strong against frictional wears.
[0053] The mobile members 41 g and 41 h are downwardly biased by means respectively of springs 41 i and 41 j such that their protrusions are pressed respectively against the fixed electrodes 41 a - 41 c and 41 d - 41 f of the first and second groups. The separation between the two protrusions on each of the mobile members 41 g and 41 h is so set as to be greater than L 1 a (=L 1 b ). Explained for the mobile member 41 g (because the other mobile member 41 h is similar), for example, the separation between its protrusions 41 g 1 and 41 g 2 is determined such that they can contact only the fixed electrodes 41 a and 41 b of the first group to connect their metallic conductors and also only the fixed electrodes 41 b and 41 c of the first group to connect their metallic conductors.
[0054] It may be reminded at this point that these mobile members 41 g and 41 h need not be made entirely of a metallic material of a high conductivity and strong against frictional wears. What is essential is that each be capable of moving in the direction of the line 44 so as to contact only the fixed electrodes 41 a and 41 b of the first group (in the case of mobile member 41 g ) to connect their metallic conductors and also only the fixed electrodes 41 b and 41 c to connect their metallic conductors. Thus, it is sufficient for this purpose if the two protrusions on each of the mobile members 41 g and 41 h are made of a friction-resistant metallic material with a high conductivity either entirely or on the contacting surfaces and if these two protrusions are electrically connected.
[0055] The two mobile members 41 g and 41 h are adapted to move to left and right in the direction of the line 44 while remaining parallel to each other as shown in FIG. 1 by the operation of the aforementioned operating element 43 .
[0056] With the first switch element 41 thus structured as explained above, if its two mobile members 41 g and 41 g are in their neutral positions as shown in FIG. 1, the protrusions 41 g 1 and 41 g 2 of the mobile member 41 g contact the fixed electrodes 41 b and 41 c of the first group to connect their conductors together in a closed condition and the protrusions 41 h 1 and 41 h 2 of the other mobile member 41 h contact the fixed electrodes 41 e and 41 f to connect their conductors together in a closed condition. In other words, the fixed electrodes 41 a and 41 b of the first group and the fixed electrodes 41 d and 41 e of the second group can be kept in an open condition with respect to each other.
[0057] If the mobile member 41 g is moved from the neutral position to right with reference to FIG. 1, its protrusions 41 g 1 and 41 g 2 come to contact the fixed electrodes 41 a and 41 b of the first group to connect their conductors in a closed condition. In this situation, the fixed electrodes 41 b and 41 c are switched into an open condition. At the same time, the other mobile member 41 h is caused to move from its neutral position to right with reference to FIG. 1 but its protrusions 41 hl and 41 h 2 keep the fixed electrodes 41 f and 41 e of the second group in the closed condition.
[0058] Similarly, when the mobile member 41 h is moved from its neutral position to left with reference to FIG. 1, its protrusions 41 h 1 and 41 h 2 come to contact the fixed electrodes 41 d and 41 e of the second group to connect their conductors in a closed condition. In this situation, the fixed electrodes 41 e and 41 f of the second group are switched into an open condition. At the same time, the other mobile member 41 g is caused to move from its neutral position to left with reference to FIG. 1 but its protrusions 41 g 1 and 41 g 2 keep the fixed electrodes 41 c and 41 b of the first group in the closed condition.
[0059] Circle portion C of FIG. 1 shows the circuit structure of the first switch element 41 . In this circuit diagram, the mobile members 41 g and 41 h and the fixed electrodes 41 b and 41 e correspond to the two moving contacts described above in the Background section. The fixed electrodes 41 a and 41 d correspond to the NO contacts and the fixed electrodes 41 c and 41 f correspond to the NC contacts.
[0060] When the mobile members 41 g and 41 h are in their neutral positions as shown in FIG. 1, the NC contacts ( 41 c and 41 f ) are in the closed condition. If the mobile member 41 g moves from its neutral position to right along the line 44 , the NC contact 41 c is released from its closed condition and the NO contact 41 a comes to be in the closed condition. If the other mobile member 41 h moves to left from its neutral position along the line 44 , the NC contact 41 f is released from its closed condition and the NO contact 41 d comes to be in the closed condition.
[0061] In summary, this first switch element 41 functions like a switch of a two-circuit, four-contact type. If the centering positions of the mobile members 41 g and 41 h is adjusted to the aforementioned neutral positions shown in Table 1 by means of the operating element 43 to be described below, two ( 41 c and 41 f ) of the four fixed electrodes 41 a , 41 c , 41 d and 41 f on both sides of this neutral position become the NC contacts and the remaining two ( 41 a and 41 d ) become the NO contacts.
[0062] The second switch element 42 is formed on the same base board (not shown) on which is formed the first switch element 41 by mounting thereon two switch mechanisms of the same structure to be described below.
[0063] Explained more in detail, the second switch element 42 is comprised of U-shaped members 42 a and 42 b set on the aforementioned base board, mobile members 42 c and 42 d each in the form of a metallic plate spring and having one end supported by a corresponding one of the U-shaped members 42 a and 42 b , moving contacts 42 e and 42 f attached to the other ends of the mobile members 42 c and 42 d , reverse L-shaped members 42 g and 42 h set on the base board and fixed contacts 42 i and 42 j set on the downwardly facing end parts of the reverse L-shaped members 42 g and 42 h.
[0064] The metallic plate spring-like mobile members 42 c and 42 d have cutout portions 42 k and 42 m which are bent so as to contact the U-shaped members 42 a and 42 b . The elastic returning force of these cutout portions 42 k and 42 m is utilized so as to normally keep the moving contacts 42 e and 42 f on the other ends in contact with the fixed contacts 42 i and 42 j in closed conditions. Thus, the fixed contacts 42 i and 42 j function as normally closed (NC) contacts.
[0065] If a downward external force in excess of the elastic returning force of the cutout portions 42 k and 42 m is applied to the mobile members 42 c or 42 d through a corresponding one of push buttons 42 n and 42 p which are individually provided, the tip portions of the mobile members 42 c and 42 d move downward and the closed conditions between the moving contacts 42 e and 42 f and the fixed contacts 42 i and 42 j are released and open conditions are set between these contacts.
[0066] Circle portion D of FIG. 1 shows the circuit structure of the second switch element 42 . In this circuit diagram, the two moving contacts 42 e and 42 f are in closed condition respectively with the fixed contacts (NC contacts) 42 i and 42 j . If a downward external force is applied to the mobile member 42 c , the closed condition between the moving contact 42 e and the fixed contact (NC contact) 42 i is released and they come to be in the open condition. Similarly, if a downward external force is applied to the other mobile member 42 d , the closed condition between the moving contact 42 f and the fixed contact (NC contact) 42 j is released and they come to be in the open condition.
[0067] In summary, this second switch element 42 functions like a switch of the two-circuit, two-contact type, having a pair of NC contacts ( 42 i and 42 j ).
[0068] The aforementioned operating element 43 is indicated by broken lines in FIG. 1 for the convenience of disclosure and is characterized as having the following four functions: (1) the function of maintaining the first and second switch elements 41 and 42 in the neutral positions as shown in FIG. 1 if there is no input from the operator (such as the operation on the knob 13 to the UP or DOWN condition as explained above); (2) the function of returning the first and second switch elements 41 and 42 to their neutral positions as soon as an input operation by the operator is released; (3) the function of moving one of the mobile members (such as the member 41 h ) of the first switch element 41 from the neutral position along the line 44 in one direction (such as to left with reference to FIG. 1) and setting one of the NC contacts (such as the fixed contact 42 j ) of the second switch element 42 in the open condition in response to an operation of the operator (such as the UP operation); and (4) the function of moving the other of the mobile members (such as the member 41 g) of the first switch element 41 from the neutral position along the line 44 in the other direction (such as to right with reference to FIG. 1) and setting the other of the NC contacts (such as the fixed contact 42 i ) of the second switch element 42 .
[0069] [0069]FIGS. 2 and 3 illustrate these functions of the operating element 43 . As shown in FIG. 2, the operating element 43 includes an operating means 43 a , which is structured similarly to the slider 28 described above with reference to FIGS. 10 - 12 and slides to left or right with reference to FIG. 1 along the line 44 as the knob 3 (also described above with reference to FIGS. 10 and 12) is moved from the UP condition to the neutral condition to the DOWN condition or from the DOWN condition to the neutral condition to the UP condition.
[0070] As the operating means 43 a is moved in one direction (such as to left with reference to FIG. 1) along the line 44 , one of the mobile members of the first switch element 41 (say, for example, the mobile member 41 h ) is moved from its neutral position along the line 44 to left with reference to FIG. 1 such that the fixed electrodes 41 d and 41 e come to be in the closed condition and the other NC contact of the second switch element 42 (say, for example, the fixed contact 42 j ) comes to be in the open condition.
[0071] If the operating means 43 a slides further to left, the fixed contact 42 j comes to be in the closed condition and the function of driving the DC motor for opening the window is established. In other words, it may be said that these participating contacts 41 h , 41 d , 41 e and 41 j together form a motor driving switch group for the UP condition (or the UP switch group).
[0072] If the operating means 43 a is moved in the opposite direction (that is, to right with reference to FIG. 1) along the line 44 , the other of the mobile members of the first switch element 41 (that is, the mobile member 41 g ) moves from its neutral position along the line to right such that the fixed electrodes 41 a and 41 b come to be in the closed condition and the other NC contact of the second switch element 42 (that is, the fixed contact 42 i ) comes to be in the open condition.
[0073] If the operating means 43 a slides further to right, the fixed contact 42 i comes to be in the closed condition and the function of driving the DC motor for closing the window is established. In other words, it may be said that these participating contacts 41 g , 41 a , 41 b and 41 i together form a motor driving switch group for the DOWN condition (or the DOWN switch group).
[0074] For the convenience of description, operations of the UP switch group (as one of the switch groups defined above) are explained with reference to FIG. 3 wherein “X-X” and “Y-Y” indicate the sectional views taken respectively along the lines X-X and Y-Y shown in FIG. 2. Step 1 indicates the initial position in the neutral condition wherein the mobile member 41 h of the first switch element 41 is located between the fixed electrodes 41 e and 41 f respectively at the center and on the right-hand side, keeping them in the closed condition. The push button 42 p of the second switch element 42 is engaged in one of the indentations on the bottom surface of the operating means 43 a and is in the raised condition. The metallic plate spring-like mobile member 42 d is not bent downward and the moving contact 42 f at the tip of this mobile member 42 d is in the closed condition with the fixed contact 42 j.
[0075] Immediately after the operating means 43 a begins to move to left from the condition of Step 1 to approach the UP condition (Step 2 ), the mobile member 41 h of the first switch element 41 remains at the position in Step 1 , keeping the fixed electrodes 41 e and 41 f in the closed condition but the push button 42 p of the second switch element 42 is out of the indentation on the bottom surface of the operating means 43 a and contacts the thick portion of the operating means 43 a . Since the push button 42 p is thus being pressed downward, the mobile member 42 d is bent downward and the closed condition between the moving contact 42 f and the fixed contact 42 j is released and they are now in the open condition.
[0076] As the UP condition progresses (Step 3 ), the mobile member 41 h of the first switch element 41 is between the fixed electrodes 41 d and 41 e respectively on the right-hand side and at the center and keeps them in the closed condition while the fixed electrodes 41 e and 41 f are in the open condition. Since the push button 42 p of the second switch element 42 is still at the thick portion of the operating means 43 a and the mobile member 42 d remains bent downward, the moving contact 42 f at the tip of this mobile member 42 d remains in the open condition with the fixed contact 42 j.
[0077] As the UP condition progresses still further (Step 4 ), the mobile member 41 h of the first switch element 41 continues to be between the fixed electrodes 41 d and 41 e to keep them in the closed condition. The push button 42 p of the second switch element 42 engages in the other indentation on the bottom surface of the operating means 43 a and is in the raised position. The mobile member 42 d returns to its horizontal position such that the moving contact 42 f at the tip of this mobile member 42 d is in the closed condition with the fixed contact 42 j.
[0078] Operations from the neutral condition to the DOWN condition is similar to those from the neutral condition to the UP condition described above and may be described by making the following replacements of symbols in the description of the operations from the neutral condition to the UP condition given above: 41 h - 41 g , 41 d > 41 a , 41 e - 41 b , 41 f - 41 c , 42 d - 42 c , 42 j 42 i , 42 f - 42 e and 42 p - 42 n.
[0079] There are shown in FIG. 4 (comprised of FIGS. 4A, 4B, 4 C and 4 D) circuit diagrams of a system for rotating (in both positive and negative directions) and stopping a DC motor for opening and closing an automobile window by incorporating the switch device 40 embodying this invention. In FIG. 4, the +B line 17 serves as the power (voltage) source on the positive electrode side (or the +B line of the electrical system for a vehicle) and the grounding line 18 serves as the power (voltage) source on the negative electrode side (or the grounding line for the system) but they are distinguishable from prior art systems wherein the voltage applied through the +B line 17 is higher (say, a source voltage of 36V for a 42V electrical system) than that in the case of a 14V electrical system.
[0080] [0080]FIG. 4A shows the circuit when the system is in the DOWN condition, FIG. 4D shows the moment when the system has returned from the DOWN condition to the neutral condition and FIGS. 4B and 4C show the system at moments in between. When the system is in the DOWN condition, each of the contacts of the first and second switch elements 41 and 42 is in the condition of Step 4 shown in FIG. 3, that is, the mobile member 41 g and the NO contact 41 a of the first switch element 41 are in the closed condition, the mobile member 41 h and the NC contact 41 f are in the closed condition and the two NC contacts 42 i and 42 j of the second switch element 42 are in the closed condition. Thus, the voltage (such as +42V) of the +B line 17 is applied to one input terminal of the DC motor 2 while the ground voltage (0V) of the grounding line 18 is applied to the other input terminal of the DC motor 2 , causing the DC motor 2 to rotate in the direction of opening the window.
[0081] If the system is released from the DOWN condition described above (say, by releasing the finger from the knob 3 referenced above), the circuit comes to appear as shown in FIG. 4B, that is, the two NC contacts 42 i and 42 j of the second switch element 42 comes to be in the open condition while the contacts of the first switch element 41 remain in the same conditions as before such that the DC motor 2 becomes disconnected from the grounding line 18 .
[0082] Next, the condition as shown in FIG. 4C is reached wherein the closed condition between the mobile member 41 g and the NO contact 41 a of the first switch element 41 is released and the mobile member 41 g and the NC contact 41 c come to be in the closed condition while the two NC contacts 42 i and 42 j of the second switch element remain in the open condition. Finally as the condition as shown in FIG. 4D is reached thereafter, the two NC contacts 42 i and 42 j of the second switch element 42 come to be in the closed condition and the both input terminals of the DC motor 2 become connected to the grounding line 18 such that the rotation of the DC motor 2 is stopped.
[0083] As explained above, the problem with prior art technology was that a large current flows through contacts when the DC motor is switched from the UP condition to the neutral condition or from the DOWN condition back to the neutral condition by switching contacts and that damages are frequently caused to the contacts due to such a large current flowing therethrough. According to the embodiment of the invention described above, the second switch element 42 is set in the open condition such that the flow route of such a large current is broken before or simultaneously as contacts of the first switch element 41 are switched. Thus, a large current is prevented from flowing through the contacts and damages thereto can be averted. Although two NC contacts are employed and this tends to increase the width, the switch device 40 need not be made larger to any significant degree and the response characteristics are not adversely affected since the contact gaps need not be increased. Since the second switch element 42 is realized with two NC contacts, furthermore, the space for the NO contacts may be utilized for increasing the contact gaps.
[0084] Although an embodiment has been described wherein the second switch element 42 was of the two-circuit, two-contact type, this may be realized with a one-circuit, one contact type, as shown in FIG. 5. The circuit shown in FIG. 5 is different from the one described above wherein the two NC contacts 41 c and 41 f of the first switch element are joined together within the switch and connected together through a single NC contact ( 42 i or 42 j ) to the grounding line 18 .
[0085] As a second example, a second switch element 42 of a two-circuit, two-contact type may be connected to the side of the positive voltage source, as shown in FIG. 6. The circuit shown in FIG. 6 is different wherein the mobile member 42 e and NC contact 42 i of the second switch element 42 are inserted between the NO contact 41 a of the first switch element 41 and the +B line 17 and the other mobile member 42 f and the other NC contact 42 j of the second switch element 42 are inserted between the other NO contact 41 d of the first switch element and the +B line 17 .
[0086] The second switch element 42 of FIG. 6 may be formed as a one-circuit, one contact type, as shown in FIG. 7. The circuit shown in FIG. 7 is different wherein the two NC contacts 41 c and 41 f of the first switch element 41 are joined together within the switch and connected together through a single NC contact ( 42 i or 42 j ) to the +B line 17 .
[0087] When either of the circuits as shown in FIGS. 6 and 7 is used, the NC contact 42 i or 42 j is set in the open condition before either of the NO contacts 41 a and 41 d of the first switch element 41 is switched from the closed condition to the open condition. Since the route for a large current is thereby broken such that damages to the contacts in the first switch element 41 can be prevented and there is no need to increase the contact gaps, the size of the switch device does not increase and its response characteristics are not adversely affected.
[0088] As a further variation, the first switch element 41 may be of a four-circuit, four-contact type, as shown in FIG. 8. The circuit shown in FIG. 8 is different wherein the two NC contacts 41 c and 41 f of the first switch element 41 are dispensed with and wherein the input terminals of the DC motor 2 are made selectively connectable to the +B line 17 through the two NO contacts 41 a and 41 d of the first switch element 41 and to the grounding line 18 through the two NC contacts 42 i and 42 j of the second switch unit 42 . In order to prevent damages to the NO contacts 41 a and 41 d of the first switch element 41 , the NC contacts 42 i and 42 j of the second switch element 42 connected to these NO contacts may be set in the open condition.
[0089] In all of the variations described above, the first and second switch elements 41 and 42 were represented as forming a single unit together but this is not intended to limit the scope of this invention. FIG. 9 shows an example of this invention having a first unit 51 containing the first switch element 41 and a second unit containing the second switch element 42 , arranged next to each other. Numeral 50 indicates a knob, which is an equivalent of the knob 3 described above with reference to FIGS. 10 and 12, provided with two indentations 50 a and 50 b adapted to engage switch operating parts of the first and second units 51 and 52 , respectively (a protrusion 51 b on a slider 51 b of the first unit 51 and a protrusion 52 a for the operation of the second unit 52 ).
[0090] As should be clear from the description of the embodiments of the invention, the route of the instantaneous flow of a large current can be broken by opening the contacts of the second switch element at an appropriate timing such that damages to the contacts in the first switch element can be prevented. Thus, the inconvenience of prior art technology when a high source voltage such as a 42V electrical system is used on a vehicle can be eliminated. Since the new technology according to this invention does not required any increase in the contact gaps, the switch unit does not become large and the response characteristics are not adversely affected. | A switch device for rotating and stopping a DC motor includes a first switch element having two moving contacts, two normally open NO contacts and two normally closed NC contacts, a second switch element having one or two normally closed NC contacts, and an operating element. The operating element serves to connect the two moving contacts individually to input terminals of the DC motor, the two NO contacts to a voltage source line at a higher voltage, and each of the two NC contacts of the first switch element to another voltage source line at a lower voltage such as the ground potential, each through the NC contact, or one of the two NC contacts, of the second switch element. The NC contact of the second switch element is maintained in an open condition during a period from when either one of the NO contacts begins to change from a closed condition to an open condition until the corresponding NC contact of the first switch element finishes changing from an open condition to a closed condition. | 4 |
RELATED APPLICATIONS
[0001] This application is a continuation of Ser. No. 12/779,011, filed May 12, 2010, titled “Surface Mount Vehicle Anti-Ram Security Systems,” the entire disclosure of which is incorporated herein by reference.
[0002] This application claims the priority of the following US provisional patent applications:
[0003] 61/216,099, filed May 12, 2009, titled “Surface Mount Bollards with Multiple Configurations,” the entire disclosure of which is incorporated herein by reference;
[0004] 61/280,452, filed Nov. 3, 2009, titled “Surface Mount Bollards K12,” the entire disclosure of which is incorporated herein by reference;
[0005] 61/283,471, filed Dec. 3, 2009, titled “K12 Surface Mount Bollards with Anti-Scaling Fence and Blast Walls,” the entire disclosure of which is incorporated herein by reference;
[0006] 61/284,504, filed Dec. 16, 2009, titled “Surface Mount Anti-Ram Anti-Scaling Anti-Blast Modular System—Perimeter Force Protection,” the entire disclosure of which is incorporated herein by reference; and
[0007] 61/341,563, filed Apr. 1, 2010, titled “Re-configurable, Surface Mounted High Security Anti-Ram Beam and Sensored Fence System,” the entire disclosure of which is incorporated herein by reference.
[0008] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyrights whatsoever.
BACKGROUND OF THE INVENTION
[0009] The invention disclosed herein relates generally to the field of perimeter security and barrier and/or anti-ram (referred to below simply as “anti-ram”) devices and systems which, e.g., protect against vehicle penetration or channel vehicle traffic, etc. In particular, embodiments of the invention relate to vehicle anti-ram systems that can be mounted on existing or partially or entirely prepared surfaces. Embodiments of the invention can be mounted on existing surfaces such as streets, sidewalks and soil without any or with minimal site preparation, although the same or similar embodiments or variations may also be installed in sites which involve site preparation or construction associated with installation and/or operation of one or more embodiments. According to some embodiments, such anti-ram systems comprise one or more bollards.
SUMMARY OF THE INVENTION
[0010] Anti-ram systems according to embodiments of the invention comprise at least one bollard section comprising a base of limited height and a plurality of spaced bollards extending upwardly from the base. According to embodiments of the invention, an anti-ram system may be erected or installed on a paved surface such as asphalt, concrete, paver stones, etc., or on an unpaved surface such as soil. According to some embodiments, anti-ram systems are readily adaptable to different terrain and installation requirements, e.g., installation on slopes, and in various angular configurations. According to some embodiments, an anti-ram system can be installed with no or little site preparation, and/or can be installed without excavation, e.g., on an existing or prepared surface.
[0011] According to some embodiments, an anti-ram system comprises a plurality of bollard sections and one or more connectors for interconnecting two or more of the bollard sections.
[0012] According to some embodiments, an anti-ram system comprises an anchor or anchor system engaging at least each end of a bollard section not connected to another bollard section. (Use of the term anchor herein encompasses an anchor system unless the context indicates otherwise.)
[0013] According to some embodiments, a system comprises high friction structure secured to a bollard section or sections and/or to a connector or connectors to inhibit sliding of the system after an impact.
[0014] According to various embodiments of the invention, an anti-ram system after impact may move a certain distance, referred to as a “stopping distance.” An anti-ram system according to embodiments of the invention may provide an acceptable stopping distance on a paved or unpaved surface, e.g., from 3 to 50 feet depending upon Department of State (DOS) and ASTM ratings. Factors that can affect the stopping distance include system weight, bollard height, on-center bollard spacing, anchoring, friction and configuration.
[0015] DOS and ASTM crash ratings for shallow and deep mount bollard systems, i.e., systems in which a bollard base and or a lower portion of a bollard, involve bollard on-center spacing of not more than 4′ and bollard heights of about 36″-40″. Some of the embodiments of the surface mount of anti-ram system disclosed herein including such bollard spacing and heights.
[0016] As mentioned, embodiments of the invention may comprise one or more bollard sections. For example: an anti-ram system comprising one bollard section includes an anchor for each end of the section; an anti-ram system comprising two bollard sections comprises a connector for interconnecting adjacent ends of the two sections and an anchor for each unconnected end of the two interconnected sections; and an anti-ram system comprising three bases comprises two connectors for interconnecting adjacent ends of two of the bollard sections, and an anchor for each unconnected end of the interconnected sections. However, according to some embodiments, an anti-ram system does not include two or any anchors.
[0017] Embodiments of anti-ram systems of considerable length, or in particular configurations, may in some applications not require an anchor or anchors, or high friction measures, etc. In such embodiments, there may be sufficient weight without anchors and/or without ballast to stop a vehicle within a desired stopping distance. For example, if the length of a system is long enough, then for a vehicle strike in the center, anchors would not be needed. The overall mass of the system may be enough to hold back the vehicle from vaulting or exceeding the desired penetration distance. In some applications, the system can be wider, or higher, etc. In some applications, e.g., in a war zone, an anti-ram system can be positioned a substantial distance from a site to be protected, e.g., temporary barracks, as opposed to an urban environment where there is a short distance fro the street to a building.
[0018] According to some embodiments, an anchor comprises deadman-type (which term encompasses deadweight-type structures) structure, e.g., a fabricated or assembled structure such as a concrete or stone block, or a container (e.g., a hollow steel box) filled with ballast, or an available structure such as a vehicle, etc. Examples of ballast include locally available or easily transportable bulk material such as sand, soil, stone, marbles, concrete, water, combinations thereof, etc. According to some embodiments, a base or bases may be anchored to non-made structure that is secured to the ground such as building walls or foundations, or to naturally occurring or man-made earthen or ground structures such as rock formations, berms, trees, walls or curbs, or to bollards or barriers that are installed in shallow or deep mount constructions, etc. According to some embodiments, anchors comprise imbedded structures such as footers which can be positioned behind a base (i.e., opposite a side of expected impact), or below a base with structure embedded for bolting the base to the anchor, or extending through or into a hole in the base, etc. According to some embodiments, anchors may comprise spikes or members that pass through a base and penetrate a paved or unpaved surface. According to some embodiments, an anti-ram system comprises an anchor system, which can comprise suitable anchors described above and/or a cable extending from at least one end of a base, or through a base or bollard section to an anchor such as a building, permanent bollard system, etc. In some embodiments, a post-tensioning system including a cable passing through at least one base or bollard section can be used to assist in interconnecting bollard sections into an integral system. In one embodiment, a conduit is positioned running lengthwise through each or selected bases, and a cable is run through the conduit or conduits and post-tensioned. This can be done for the entire system or portions thereof to increase the stopping power of the system or portions thereof.
[0019] An anti-ram system according to some embodiments can be installed over uneven surfaces such as extending over a curb. In such embodiments, portions of the system contacting the curb receive an increase in the friction force, which compensates for some or all of a base not contacting the curb or the street below. In some embodiments, a connector is provided for bollard sections on a street and on a curb.
[0020] According to some embodiments, a base or bases can be fully or partially below grade in a space or excavation, etc., e.g., partially or fully buried, etc., as a permanent or temporary installation.
[0021] Adjacent bollard sections of an anti-ram system according to various embodiments of the invention may be interconnected at various angles such that an anti-ram system may extend along a straight line, or along lines at 90° or 45°, or other angles to each other, or along curved lines. Various connectors are provided in accordance with embodiments of the invention to achieve various system configurations.
[0022] Connectors according to some embodiments of the invention interconnect two adjacent bollard sections and engage at least one bollard extending from each base of the two interconnected sections, e.g., a bollard passes through a hole in the connector. Such engagement produces a locking effect between and among bollard sections that has the effect of an integral base formed of individual base units. As a result, the interconnected bollard sections cooperate to resist an impact This assists in causing an anti-ram system with locked bollard sections to react as a unit to an impact, rather than just the impacted bollard section reacting. This brings aspects of the overall anti-ram system to bear against an impact, including non-impacted bases and anchors.
[0023] According to some embodiments, tabs, stubs or keyed structures may be provided on adjacent interconnected bases which are engaged by a connector interconnecting the adjacent bases. According to some embodiments, a tab may comprise a bollard stub, e.g., constructed similar to a bollard but with a height only sufficient to engage a hole or receptacle in a connector. Engagement of a connector with a base via a bollard and another structure such as a tab, stub or key, assists in stabilizing and strengthening connection of bollard sections.
[0024] According to some embodiments, a connector may include sides projecting downward along the front and back which in some embodiments extend to the front and back sides of adjacent bases and aid in the securing of the connector. Such connectors may form an enclosure similar to a base. In some embodiments, a connector may be secured by fasteners to a base or bases. In some embodiments, a connector includes one or more bollards secured thereto.
[0025] A base may be constructed of any suitable material, preferably steel, and in any suitable configuration, size and weight. Bases of various weights can be constructed. The weight of a base depends upon factors including size, materials, construction, whether a base is ballasted and if so, the ballast. According to some embodiments, ballast such as that described above may be provided. Considerations in determining the weight of bases include portability, installability and stopping distance. Various applications may involve tradeoffs, e.g., lighter weight for portability (especially by air or to remote locations) where a longer stopping distance can be tolerated. Also, weight can be increased for a particular anti-ram system comprising given bases but with heavier deadman anchors, particularly ballasted deadman anchors. According to some embodiments, bases are constructed according to a limited number of pre-set designs, each suitable for a range of applications. According to some embodiments, bases may be specially constructed for a particular application.
[0026] According to some embodiments, a base forms a closed enclosure, and one or more openings are provided for ballast to be introduced. In these embodiments, the ballast is of a size to pass through the opening(s). According to some embodiments, a base forms an open enclosure. In these embodiments, larger size ballast may be used, and granular ballast such as sand, soil, crushed stone, concrete, etc., may be used as filler. According to some embodiments, an anti-ram system comprises deadman anchors at locations in addition the ends of the system to increase the overall weight of the system.
[0027] According to some embodiments, a base or bases may be installed angled front to rear into an unpaved surface to decrease the stopping distance compared to the base(s) being flat on the surface.
[0028] The overall weight of a bollard section depends not only upon the weight of the base but also upon the weight of the bollards. According to embodiments of the invention, the weight of a bollard section can be increased or decreased by the particular diameter (cross-section) and height of the bollards, and the material of which the bollard is made, and whether the bollard is ballasted or not.
[0029] According to some embodiments, the height of a base depends upon, e. g., desired weight, portability and installability and site conditions regarding passage through the base. According to one embodiment, the height of a base is generally the height of a step, e.g., about 7 or 8 inches. However, the height could be more or less depending upon site requirements or preferences and the desired weight of a base.
[0030] Base size depends upon factors including weight, portability, performance, stopping distance and site considerations. According to some embodiments, the width of a base is such as to resist tipping and sliding of the base upon impact, and to assist in providing a desired weight. According to some embodiments, the length of a base is sufficient to accommodate at least two bollards, which, according to some embodiments, are spaced about 3 feet to about 5 feet apart, and either a connector or anchor at each end. According to some embodiments, the length of a base is such as to resist sliding of the base upon impact, to assist in providing a desired weight and portability.
[0031] A bollard can be secured to a base in any suitable manner. Considerations in determining securement of a bollard to a base comprise resistance to rotating or separating during impact and field installability. According to some embodiments, a bollard is secured to a base in a portion of the base reinforced by one or more structural members. According to some embodiments, a bollard is installed through a top in engagement therewith, e.g., through a hole in the top which is only slightly larger than the cross-section of the bollard or smaller than a ring or other engagement or stop structure on the bollard. According to some embodiments, a bollard is attached to a base with at least one fastener. According to some embodiments, a bollard is secured to a base with at least one weld.
[0032] According to some embodiments, e.g., for installation on hard or paved surfaces, a high friction structure comprises a mat or pad of high friction material, e.g., natural or synthetic rubber, secured to the bottom of a base and/or connector. According to some embodiments, e.g., for installation on unpaved surfaces such as soil, protrusions or spikes are attached to the bottom of a section to dig into the surface.
[0033] According to some embodiments, anti-ram devices and systems include structure to allow and/or facilitate passage therethrough of pedestrians including those using aids for the handicapped such as wheelchairs, walkers, etc., and for bicycles, carriages, etc., and for passage therethrough of vehicles upon a change in configuration, e.g., retracting or removing one or more bollards, or pivoting of a bollard section.
[0034] According to some embodiments, bollard sections are modular for portability and ease of installation and possible removal and reuse.
[0035] According to some embodiments, anti-ram devices and systems can be installed for temporary use, e.g., for temporary perimeter security next to buildings other structures, to temporarily close off areas, e.g., as storage areas, to separate roadways from pedestrian areas, for street closures, and for other uses. According to some embodiments, anti-ram devices and systems can be rapidly deployed, installed and removed for civilian and military applications.
[0036] According to some embodiments, an anti-ram system comprises modular bollard sections. According to some embodiments, the modular bollard sections comprise bollards and the system comprises modular connectors. According to some embodiments, such modular components are portable and are erected on site into an anti-ram system, and in some embodiments without field welding and/or bolting. According to some embodiments, modular components are fabricated from parts on site. According to these embodiments, the modular components are shipped or stored broken down and assembled on site. According to some embodiments, an anti-ram system erected from modular components can be disassembled for subsequent reuse.
[0037] According to some embodiments, spacers are provided to assist in erecting a modular anti-ram system. According to some embodiments, two bases are positioned with a spacer therebetween, which may be left in position later removed and replaced with a similarly configured modular connector.
[0038] An anti-ram system according to an embodiment of the invention comprises a plurality of bollard sections extending along a line or lines, each section comprising a base and a plurality of bollards secured to the base, one or more connectors, each connecting two bollard sections together at adjacent ends thereof along a line and an anchor engaging a bollard section at each end of the system, wherein each base comprises a bottom, sides and a top secured together to define an enclosure of limited height, e.g., in the approximate range of 4″ to 18″, each bollard of the plurality of bollards of a section extending from the enclosure upwardly from the bottom of the section through a hole in the top of the section.
[0039] As discussed above, the ant-ram system of claim 1 may comprise one or more of the following: ballast in the enclosure of one or more bollard sections; and high friction structure secured to a base of one or more bollard sections extending along the bottom thereof exterior to the enclosure.
[0040] According to an embodiment, at least one anchor of the anti-ram system comprises: a deadweight engaging a bollard section at an end of the system; and/or a part of a man-made structure anchored to the ground and engaging a bollard section at an end of the system; and/or a natural structure anchored to the ground and engaging a bollard section at an end of the system.
[0041] A connector for the anti-ram system may, according various embodiments, engage at least one bollard of a section the connector connects, and/or structure projecting from the top of a bollard section spaced from the engaged bollard. According to some embodiments such projecting structure may comprise a bollard stub secured to the base of the connected bollard section or key configured structure.
[0042] A connector for the anti-ram system may comprise according to some embodiments: a 180° connector including a top that extends over ends of two adjacent connected bollard sections; and/or a 45° connector including a top that extends over ends of two adjacent connected bollard sections. According to one embodiment, the 45° connector may comprise sides and a bottom which with a portion of the top define an enclosure, the connected bollard sections being spaced with the enclosure positioned in the space and portions of the top extending beyond the enclosure and over the ends of the two adjacent connected bollard sections. According to one embodiment, the enclosure of the 45° bollard may include ballast. According to one embodiment, the enclosure of the 45° bollard may include a bollard secured thereto extending from the connector enclosure upwardly from the bottom thereof through a hole in the top thereof.
[0043] According to one embodiment, a 180° connector includes a central lower portion and raised portions on each side of the central portion, the raised portions extending over ends of connected to adjacent bollard sections, the connector defining a lower region between the two connected bollard sections.
[0044] According to one embodiment, a 180° connector includes a lower portion and a raised, the raised portion extending over and connected to one of the two connected bollard sections whose top is at higher elevation than the top of another of the two connected bollard section, and the lower portion extending over and connected to the bollard section whose top is at an elevation lower than that of the one bollard section.
[0045] According to one embodiment, a 180° connector comprises a vehicle passage comprising at least one retractable or removable bollard, the connector being position between and connected to ends of the two connected bollard sections.
[0046] According to one embodiment, a connector comprises a bollard secured thereto, the connector being position between and connected to ends of the two connected bollard sections.
[0047] According to one embodiment, the enclosure comprises a flat bottom and a flat top.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] The invention is illustrated in the figures of the accompanying drawings, which are meant to be exemplary and not limiting, and in which like references are intended to refer to like or corresponding parts.
[0049] FIG. 1 is a rendering illustrating a vehicle anti-ram system according to an embodiment of the invention installed along the perimeter of a facility between a roadway and a building and an area adjacent the building.
[0050] FIG. 2 is a perspective view of three interconnected bollard sections of a vehicle anti-ram system according to an embodiment of the invention.
[0051] FIG. 3 is an exploded perspective view of the three bollard sections and connecting elements depicted in FIG. 2 , with the connecting elements shown disconnected from the bollard sections.
[0052] FIG. 4 is a perspective view of one of the bollard sections depicted in FIG. 2 .
[0053] FIG. 5 is an exploded perspective view of the bollard section depicted in FIG. 4 and showing additional components.
[0054] FIG. 6 is a top plan view of the bollard section depicted in FIG. 4 showing in broken lines internal gussets and sides of a bottom section.
[0055] FIG. 7 is a side elevation view of the bollard section depicted in FIG. 4 showing in broken lines the internal gussets and sides of the bottom section also shown in FIG. 6 and a bolt secured to the bottom section for attaching a bollard.
[0056] FIG. 8 is side elevation view of a bollard showing in broken lines engaging structure in the form of internal threading to mate with the bolt depicted in FIG. 7 .
[0057] FIG. 9 is an exploded perspective view of an embodiment of a 45° connector for two bollard sections.
[0058] FIGS. 10A-10F are perspective views of connectors according to other embodiments of the invention.
[0059] FIG. 11 is a perspective view of a portion of an anti-ram system including a vehicle pass-through according to an embodiment of the invention.
[0060] FIG. 12 is a perspective view of an anchor which is connected to an end of the anti-ram system depicted in FIG. 2 .
[0061] FIG. 13 is a perspective view of a connector also acting as a connector also acting as an anchor that can be attached to an end of permanently installed anti-ram system according to embodiments of the invention.
[0062] FIG. 14 is a perspective view of an end of an anti-ram system according to an embodiment of the invention engaged with a building as an anchor.
[0063] FIG. 15 is a perspective view of a part of an anti-ram system which includes an anchor in the form of a ballasted container engaged with an end of the system.
[0064] FIG. 16 is an exploded perspective view of two bollard sections and a connector of a vehicle anti-ram system according to another embodiment of the invention.
[0065] FIG. 17 is an exploded perspective view of portions of two bollard sections and a connector of a vehicle anti-ram system according to another embodiment of the invention.
[0066] FIGS. 18A-18C are perspective views of spacers according to embodiments of the invention that can be used during installation of an anti-ram system according to embodiments of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0067] Embodiments of the invention are described below with reference to the accompanying drawings which depict embodiments of anti-ram systems and components thereof. However, it is to be understood that the invention encompasses components and systems other than those illustrated. Also, the invention is not limited to the depicted embodiments and the details thereof, which are provided for purposes of illustration and not limitation.
[0068] Some embodiments require no site excavation or any physical connection to the ground or other structure. Some embodiments are intended to work equally well as an excavated and permanently cast in place anti-ram system. Some embodiments are modular, which allows quick deployment, installation and removal. For example, according to some embodiments, modular components can be fabricated off-site and air-lifted and/or trucked to the site ready for installation. According to some embodiments, ballast can be added off site and the bollards can be inserted off site as well. Fully prefabricated bollard sections can then be transported to the site. According to some embodiments of a modular system, like components are interchangeable, and various components mate and/or interlock, etc., with other components.
[0069] According to some embodiments of the invention, a moving vehicle can be stopped based on one or more of the following and other factors. The mass (weight) of the system, the deformation of system components, e.g., bollards, bases, anchors, and high friction measures to inhibit movement of components after impact. When a vehicle impacts a bollard of the system, because components of the system are interconnected, all or a substantial portion of the system resists displacement, and not only the section impacted, and more of the system than the impacted bollard and section are available for deformation.
[0070] Referring to FIG. 1 , a vehicle anti-ram system 100 extends along a perimeter of a facility 102 between the facility and a roadway 104 . The anti-ram system 100 includes three sections 110 , 112 and 114 . Each section comprises a base 120 and a plurality of bollards 122 . The system 100 also includes anchors 124 in the form of deadmen at opposite ends of the system. The system also includes connectors 126 connecting the three sections together. Details of various embodiments of bollard sections, connectors and anchors are discussed below in connection with other figures.
[0071] The bollard system 130 depicted in FIGS. 2 and 3 comprises three bollard sections 132 and two connectors 134 and 136 . FIGS. 2 and 3 do not depict a high friction mat 170 depicted in FIG. 5 or anchors depicted in other figures. Each bollard section 132 comprises a plurality of bollards 138 . FIG. 12 depicts an anchor 140 for each end of the system, which is not depicted in FIGS. 2 and 3 . Connector 134 connects two spaced bollard sections at an inside (opposite the side of expected impact) angle of 45°. Connector 134 includes a base 140 and a bollard 138 . Connector 136 connects two abutted bollard sections along a straight angle and may comprise a single plate or two plates as shown.
[0072] Referring to FIGS. 4-7 , each bollard section 132 comprises a base 144 to which the bollards 138 are attached and a tab or bollard stub 146 used with a connector 134 and 136 to interconnect adjacent bollard sections. Tabs 146 may be configured as shorter height bollards. A connector such as connector 136 engages a base at two spaced points, one point being the engagement of a bollard 138 with a hole 228 in the connector, and the other point being engagement of a stub 146 with a hole 228 in the connector. Engagement of a connector with a base via a bollard and another structure such as a tab, stub or key ( FIG. 16 ), assists in stabilizing and strengthening connection of bollard sections. Each base is configured as a closed enclosure and may be filled with ballast through openings 160 ( FIG. 5 ) closed by covers 162 (not shown in FIG. 6 ). The covers 162 can be attached to the base 144 by fasteners, e.g., screws 164 ( FIG. 4 ). A high friction mat or pad 170 ( FIG. 5 ) may be provided for each base 144 . One way of securing the mat to the base is by folding ends of the mat upwardly along sides of the base, and attached the folded up ends of the mat to the base with straps 174 and fasteners, e.g., screws (not shown) in holes 178 , 179 , 180 . One added benefit of using a rubber pad is that a system can be placed on a quality surface, such as expensive pavers, and then removed without damaging the surface or leaving marks. As depicted in FIG. 5 , the bollards 138 and tabs 146 are removable.
[0073] Referring to FIGS. 6 and 7 , a base 144 may comprise a bottom section 190 and a top 192 . The bottom section 190 includes a bottom 193 and sides 194 and forms an enclosure for ballast 200 , illustrated as speckled in FIGS. 6 and 7 . The bottom section 190 may be formed in any suitable manner, e.g., from a plate by suitable bending and welding operations. The bottom section 190 also includes structural members in the form of gussets 196 extending from the front to the rear of the base and forming reinforced compartments within which the bollards and tabs are secured to the base. The gussets 196 also form compartments for ballast. A top 192 is secured to a bottom section in any suitable manner, e.g., by welding or fasteners. Bases made be constructed in any suitable manner and may include structural members for reinforcement or other purposes other than the gussets 196 . The base 144 includes holes 198 through which bollards 138 and stubs 146 pass.
[0074] Referring to FIGS. 7 and 8 , a bollard 138 may be secured to a base 144 with a fastener system comprising a threaded stud or bolt 204 attached to the base and a threaded bore or plug 206 in a solid section 208 of a bollard ( FIG. 8 ). A ring 210 on the lower end of the bollard is positioned to function as a stop for the bollard to engage the top 192 . A bollard 138 is inserted into the base through a hole 198 in the top 192 and threaded to a bolt 204 until the ring 210 engages the top 192 . Alternatively, the bollards may be secured to the bottom section first and then the top secured to the bottom section with the ring engaging the top in the interior of the base. Bollards are hollow above the solid section 208 and are filled with a ballast such as concrete.
[0075] A bollard 138 is held to a base during impact by engagement with the top 192 through a hole 198 and securement to the base by a bolt 204 . This is sufficient to transfer impact to the base by a bolt 204 . This is sufficient to transfer impact to the base of the section. That base and the system it is connected to counteracts as described above.
[0076] Bollards may be made of any suitable material such as steel, e.g., 10″ schedule 120 steel. Bollards may have any suitable height, for complying with DOS and are in some embodiments in the range of 36″-40″.
[0077] A bollard 138 may be secured to connector 134 in a similar manner.
[0078] Tabs or stubs 146 may be installed in the same manner as bollards and may be made of the same or similar material. For example, a tab 146 may be identical to the solid section 208 of a bollard and sized to protrude from the top 192 a distance approximately equal to the thickness of a connector, e.g., about 2″.
[0079] A base may be made of any material suitable for the application, e.g., steel, but other materials may be used. Various thicknesses may be used depending upon the application, e.g., 2″ thick steel plate.
[0080] According to some embodiments, the width of a base is from about 3 feet to about 6 feet or more. According to some embodiments bollard placement is such as to be from about 3 feet to about 4 feet on-center (to comply with DOS ratings) apart relative to bollards on the base and a bollard on an adjacent interconnected base or connector. For example, a base may have a length of from about 6 feet and up depending upon portability and other factors. For example, the height of a base can be from about 4 inches to about 18 inches or more. In one exemplary embodiment, a base may be about 12″ by about 4′ by about 14′. A bollard section may weigh 20,000 lbs or more, or less, depending upon factors discussed herein. However, as mentioned, bases may be sized and bollard spacing and height selected for various applications and DOS or ASTM crash test ratings such as K4, K8, K12, etc.
[0081] According to some embodiments, a base comprises steel plates secured together to form an enclosure. According to some embodiments, a base comprises structural members, e.g., reinforcing or supporting, members such as gussets, channels, tubes, angles, beams, etc., secured to a plate or plates of the base. According to some embodiments, a base comprises a bottom section 192 including a bottom 193 and sides 194 , and the structural members 196 are secured to the bottom and/or the sides. According to some embodiments, the structural members are welded to the bottom section. According to some embodiments, the structural members are attached to the bottom section by fasteners.
[0082] According to some embodiments, a base comprises the bottom section 192 and a top plate 192 secured to the bottom section to form a closed enclosure. According to some embodiments, the top is welded to the bottom section. According to some embodiments, the top is secured to the bottom section by fasteners. According to some embodiments, the top comprises one or more openings 160 for introducing ballast.
[0083] Connectors of various configurations may be used to interconnect bollard sections. FIGS. 9 and 10 depict examples. The connector 134 depicted in FIG. 9 connects two bollard sections 132 at a 45° inside angle, as depicted in FIGS. 2 and 3 . The connector 134 comprises a bottom section 220 and a top 222 . The bottom section 220 in one embodiment can be similar to the bottom section 190 of a base 144 . For example, the bottom section 220 may include structural members defining a channel for a bollard 138 (not shown in FIG. 9 ) and a chamber or chambers to hold ballast. A high friction mat 226 may be provided for the connector, and secured by straps and fasteners as described above for mat 170 . The top 222 also includes holes 228 for engaging bollards 138 and stubs 146 of bollard sections that the connector 134 interconnects, as depicted in FIGS. 2-3 . The connector 134 also includes a hole 160 for introducing ballast, and a cover (not shown, but the same as cover 162 ) for the hole 160 .
[0084] As mentioned, connectors may be provided to achieve various system configurations and to accommodate various features such as traversing a curb, providing a pedestrian passage, providing a vehicle passage, etc. In FIGS. 2 and 3 , connector 136 comprises a single plate or two narrower plates with holes with holes 228 for bollards 138 . Connector 136 provides a 180° connection of bollard sections 132 .
[0085] FIG. 10A depicts another embodiment of a 180° connector 230 with sides 232 which fit over the sides 190 of the bases 144 . Connector 230 includes only holes 228 for bollards and no holes for stubs 146 .
[0086] FIG. 10B depicts connector 240 with sides 242 which provides an inside 45° connection. Like connector 230 , connector 240 includes only two holes 228 for bollards 138 , and is intended for use with bollard sections without stubs 146 .
[0087] FIG. 10C depicts an embodiment of an outside 45° connector 250 , which includes only two holes 228 .
[0088] FIG. 10D depicts an embodiment of an inside 45° connector 260 , which includes only two holes 228 for bollards and no sides.
[0089] FIG. 10E depicts an embodiment of a 180° connector 270 that forms a passage for handicapped pedestrians using aids such as wheelchairs and walkers, etc., or for bicycles, carriages, etc. Bases such as base 144 are spaced to accommodate connector 270 , which includes a lower portion 272 that rests on the street or sidewalk, etc., and raised portions 274 on each side of the lower portion 272 which each has a height slightly higher than the height of the adjacent base to fit thereover. Connector 270 includes holes 228 for bollards 138 . The lower portion 272 eliminates a step otherwise presented by abutting bases.
[0090] FIG. 1 OF depicts a connector 280 which transitions between a base on a sidewalk or higher elevation and a base at street level or a lower elevation. Connector 280 includes an upper portion 282 that attaches to the base at the higher elevation and a lower portion 284 that attaches to a base at a lower elevation. Connector 280 includes sides 286 and only two holes 228 for bollards.
[0091] FIG. 11 depicts a connector 290 that also functions as a vehicle passage through an anti-ram system. Connector 290 is interconnected to spaced bollard sections 300 , which are only partially shown. Attached to opposite sides of connector 290 are 180° connector parts 292 , similar to 180° connector 230 (or connector 272 ). Connector parts 292 each include a hole 228 for a bollard and are connected to bases as described above. Other suitable structure may be provided for interconnecting connector 290 with adjacent bases.
[0092] Connector 290 comprises one or more retractable or removable bollards 296 , which can be conventional. In the depicted embodiment, bollards 296 retract into channels referenced by 298 . Connector 290 also comprises entrance and exit ramps 300 , 301 which lead to an elevated central section 304 which is approximately the height of the adjacent bases, but could be higher or lower. The height of the central section in one embodiment is sufficient to accommodate channels 298 for the bollards. In use, the bollards are normally extended as shown in FIG. 11 , and retracted when an authorized vehicle is to pass through the bollard system. The bollards can be retracted and extended manually or automatically (e.g., hydraulically), in accordance with the prior art.
[0093] As discussed above, embodiments of bollard systems may include an anchor or anchors at the ends of the system. (However, as also discussed above, not all embodiments include an anchor or anchors.) FIG. 12 depicts one embodiment of an anchor 134 in the form of a deadman which includes an upper portion 322 which is positioned on top of a base, and a lower portion 324 which is configured to extend over the end of the base and contact the surface supporting the base. The anchor 140 also includes a projection 328 projecting downwardly from the bottom of the upper portion 322 . The projection 328 mates with similarly configured a hole in the base (not shown) to properly seat the anchor and to help hold the anchor in position. Instead of a hole in the base, a bracket (not shown) with a hole configured to mate with projection 328 , may be provided to be attached to the top of the base positioned to receive the projection 328 . Anchor 140 may be solid, e.g., made of concrete, or may be a hollow steel box having an opening on the top (or open at the top) through which ballast can be introduced. According to one embodiment, the anchor 134 has a width about the width of the base, and is a length about the spacing between bollards or larger and any suitable height.
[0094] FIGS. 13-16 depict other embodiments of anchors. In FIG. 13 , a connector 340 , similar to connector 280 , anchors bollard section 132 , mounted on a street, to a permanent shallow or deep mount bollard 342 mounted on a sidewalk. In FIG. 14 , an end 101 of the bollard system 100 extends along a portion of a building wall 350 , which functions as an anchor. In FIG. 15 , an anchor in the form of a container or deadman 360 filled with ballast abuts the end of a bollard system 100 . As depicted, the anchor 360 also abuts a curb 364 . According to one embodiment, approximate size of the container may be 6 ft x 6 ft x 10 ft, and the ballast may be sand.
[0095] As discussed above, anchors may also comprise spikes or rods or other structure which passes through a base and penetrates a paved or unpaved surface. According to one embodiment depicted in FIG. 4 , a bracket 141 having a hole 143 is attached to base 132 . A spike 145 passed through the hole 143 is driven into the ground and can function as an anchor.
[0096] As mentioned above, an anchor may comprise cabling and/or an anti-ram system may include a post-tensioned cable or cables. According to one embodiment depicted in FIG. 4 , a conduit 355 extends lengthwise along a rear portion of a base which is suitably secured to the base such that a tightened or tensioned cable 357 passing through the base will resist movement of the base. A cable may be passed through one or more bases, and either anchored at either or both ends or connected to conventional post-tensioning structure. As mentioned, cabling either as or part of an anchor or as a post-tensioning system for one or more bollard sections can strengthen an anti-ram system and reduce the stopping distance.
[0097] FIGS. 16 and 17 depict other embodiments of bollard sections. Bollard section 360 in FIG. 16 comprise removable bollards 362 which each include a tapered, rectangular bottom section 364 which mates with a similarly configured channel or hole 366 in the base 370 . The bottom section 364 includes a centrally positioned treaded bore or plug 372 which receives a bolt (not shown) passing through a hole 374 in the base to secure the bollard to the base. Except for the bottom section 364 , bollards 362 can be similar to bollards 138 . Securement is also provided by the mating structure 364 , 366 of the bollard and the base. A connector such as connector 230 may be used to interconnect bases. A system of bollard sections 360 may include high friction mats and anchors (not shown) as described above.
[0098] Bases 370 of bollard sections 360 include a key 375 aligned with a bollard at each end of the base instead of a bollard stub 146 . Correspondingly, connectors, e.g., connector 230 , include a similarly configured keyway or hole 377 which mates with the key 374 . This key/keyway structure stabilizes the connector at each base by virtue of engagement at two points, similar to engagement of a connector by a bollard and a stub (see FIG. 2 , for example.)
[0099] In the embodiment depicted in FIG. 17 , a system 380 of bollard sections 381 are interconnected by a connector 382 which is bolted to the bases 384 . The bollards 386 may be constructed and installed as described for bollards 138 . Connector 382 comprises a top plate 388 with sides 389 , holes 390 for pins 392 and holes 228 for the bollards. The bollard sections 381 each include holes 393 for pins 392 , and a bollard 386 secured to the end 394 thereof. Therefore, the bases can be spaced to achieve a desired spacing between the end bollards. During installation, this spacing can be provided by a spacer 400 , which can be removed (or can remain) after the bollard sections have been positioned. (Spacers are discussed below in connection with FIGS. 18A-18C .) Then the connector 382 is installed. The top plate is positioned on the bases with the end bollards passing through the bollard holes 228 in the top plate, and the holes 390 aligned with holes 393 in the ends of the bases 384 . The pins 392 are inserted through the holes 390 in the top plate into the holes 393 in the bases. The ends 394 of the bollard sections are recessed to receive the top plate 388 flush with the top of the base. Ends of the bollard sections 381 may be constructed as described above to cooperate with an anchor, or to be interconnected with other bollard sections. A system 380 of bollard sections 381 may include high friction mats and anchors (not shown) as described above.
[0100] Anti-ram systems according to embodiments of the invention may be installed in any suitable manner. Generally, a base is positioned and then ballasted if applicable. Then a spacer or spacers are positioned, if used. Then a connector is positioned. Then bollards and stubs are installed, although bollards not engaged by a connector can be installed before the connector is positioned. According to some embodiments, no welding or bolting is required, although if the system is to be made permanent or semi-permanent, for example, the components can be welded together. A system not installed using welding or bolting can be disassembled for re-use rapidly. In embodiments utilizing modular components, assembly and disassembly are simplified because, for example, similar components are interchangeable, and spacing and angle configuration, etc. can be achieving using a range of connectors. Also, modular systems can more easily be reconfigured.
[0101] One embodiment of an installation procedure is described below. To facilitate transporting and installing bollard sections, channels for entry of forklift arms are provided, e.g., channels 401 depicted in FIGS. 4 , 11 and 14 - 16 .
[0102] The bollard sections are positioned into the desired configuration of an anti-ram system using forklift trucks and spacers such as those depicted in FIGS. 18A-18C . FIG. 18A depicts a spacer for a 180° connector. FIG. 18B depicts a spacer for an inside 45° connector. FIG. 18C depicts a spacer for an outside 45° connector. FIG. 18D depicts a spacer for a 90° connector.
[0103] A first bollard section is fork-lifted into position along the line of the anti-ram system positioned with the bollard side of the section (which is the side on which the bollards are closest to a side (front) of the section facing the threat. For bollard sections that are to be ballasted, sand or other ballast in introduced into the base and the ballast holes covered.
[0104] A second bollard section fork-lifted into position abutting an end of the first bollard section and filled with ballast. (Spacers are not used where a connector such as connector 136 or 230 is used. However, for other connectors, the second bollard section is positioned spaced from the first bollard section by an appropriate spacer.)
[0105] For the first bollard section, install the center bollard (without the lower ring or band) by inserting the bollard into the forward hole in the base. The bolt securing the bollard to the base is tightened.
[0106] For a straight angle connection, the connector plate 230 or the connector plates 136 plates are fork-lifted into position over the forward and rear holes in the bases of the first and second bollard sections for the bollards and stubs. The front bollards (with the rings) are installed through the forward holes and the stubs (also with rings) installed through the rear holes and thorough the holes in the connector plate(s). The bolts securing the bollards and stubs to the bases are tightened.
[0107] The center bollard for the second bollard section is installed as described for the center bollard of the first bollard section.
[0108] Forklift a third section into position abutting and flush with the second bollard section and fill with ballast. Forklift the connector plate(s) for another 180° connector and position it over the forward and rear holes of the second and third bollard sections.
[0109] Install a bollard and a stub in each end of the second and third bollard sections, and tighten the securing bolts. Install the center bollard.
[0110] Continue sequence until all of the bollard sections are installed.
[0111] According to some embodiments, since excavation and site preparation is not needed generally needed, a 65′ modular anti-ram system can be deployed in as little as about one hour, e.g., using a single fork lift truck or small crane and, e.g., with one or two personnel. Typically, not more than a preliminary review of the site is required since what lies below the system is typically not a concern. Anti-ram systems requiring excavation or substantial site preparation may take days or weeks to be installed depending on what is underground, construction and traffic permits, etc. Also, where excavation is required, additional time and resources are typically needed to remove and dispose of concrete, debris and soil.
[0112] An additional application of embodiments of the invention is as temporary vehicle barriers such as so-called Jersey Barriers or K-rails. These barriers are intended to be used parallel with the roadway to guide errant vehicles back in a lane, but not to stop vehicles at a 90° strike. For impacts, such barriers would tend simply to slide and have no or little real anti-ram capabilities. Although such barriers may have been used soon after 9-11, there use was based mainly on availability. Embodiments of surface mount anti-ram systems disclosed herein can be used in many if not all of such lane barrier applications.
[0113] Embodiments of the disclosed invention have been described and illustrated in an exemplary and non-limiting sense, and are not to be limited to the precise details of methodology or construction set forth above. For example, variations and modifications of bollard sections, bases, bollards, connectors, high friction mats, anchors, etc. will be evident to those skilled in the relevant arts from the disclosure herein and are intended to be encompassed by the disclosure. | Disclosed anti-ram systems comprise at least one bollard section comprising a base of limited height and a plurality of spaced bollards extending upwardly from the base, which may be erected or installed on a paved surface such as asphalt, concrete, paver stones, etc., or on an unpaved surface such as soil, and need not be partially of fully buried, and yet can qualify for Department of State crash ratings previously assigned to buried bollard systems. Disclosed anti-ram systems also comprise a plurality of bollard sections and one or more connectors for interconnecting two or more of the bollard sections, and may also include an anchor or anchor system engaging at least each end of a bollard section not connected to another bollard section. The bollard sections may be filled with ballast and high friction structure may be attached to the bottom of the bollard sections to resist sliding after impact. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/372,743, filed Apr. 12, 2002 under 35 U.S.C. § 119(e), which is hereby incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to absorbent materials for use in absorbent articles such as diapers and to processes by which to produce such absorbent materials. More particularly, the present invention relates to absorbent materials exhibiting improved liquid transport performance that further include synthetic fibers.
BACKGROUND OF THE INVENTION
[0003] Absorbent articles are widely used in a variety of applications. To function efficiently, such absorbent articles must quickly absorb body fluids, distribute those fluids within and throughout the absorbent article and be capable of retaining those body fluids. In addition, the absorbent article should be sufficiently soft and flexible so as to comfortably conform to body surfaces and provide close fit for lower leakage.
[0004] Exemplary absorbent articles available in the market today include diapers, feminine hygiene products, incontinence pads, and the like. Almost all absorbent articles include at least three elements: a topsheet, a backing sheet and an absorbent core disposed therebetween. The topsheet, also commonly referred to as a “facing layer,” is positioned closest to the wearer. The topsheet passes liquids through its thickness, serves as containment means for the absorbent core and feels soft against the wearer's skin. The backing sheet, also referred to as a “backing layer,” is positioned directly adjacent to the wearer's undergarments. The backing sheet likewise serves as a containment means for the absorbent core, and also provides a waterproof barrier between the absorbent core and the wearer's undergarments following a liquid insult.
[0005] The absorbent core, also referred to as an absorbent panel, is generally designed to absorb and retain body exudates entering the absorbent article through the topsheet. The absorbent core is generally formed from hydrophillic fibers. For example, absorbent cores may be formed from cellulosic fibers, such as cellulosic fiber derived from wood pulp and the like. Absorbent cores derived from wood pulp fiber are widely used and commonly referred to in the art as “fluff pulp”.
[0006] Unfortunately, liquid insults generally impinge the topsheet, and are subsequently transferred to the absorbent core, in relatively small, localized areas. Further, the total amount of liquid delivered to these small areas can be quite significant. Such high delivery rates are problematic because the acquisition rate of the absorbent core is generally lower than the delivery rate of the liquid insult. Thus the absorbent capacity of the absorbent core within the area of liquid entry can quickly become overwhelmed, causing the liquid to pool until it is able to diffuse into the absorbent core over time. In addition, as the absorbent core becomes saturated by successive liquid insults, the intake performance of conventional absorbent cores dramatically decreases, further exacerbating the problem. More specifically, the acquisition rate of conventional absorbent cores generally decreases significantly with each successive liquid insult.
[0007] Absorbent gelling particles may be incorporated into the absorbent core to improve its acquisition rate. Unfortunately, gelling particles swell as they absorb the insult. The swollen particles diminish the void volume of the absorbent core, reducing its ability to rapidly absorb subsequent insults.
[0008] Optional liquid transport layers may be included within absorbent articles to facilitate the lateral spreading of the fluid, and further to rapidly transfer and distribute the insult to the absorbent core. The liquid transport layer, also commonly referred to as a transitional layer, transfer layer, acquisition layer or surge management layer, is typically disposed between the topsheet and absorbent core to help prevent the liquid from pooling and collecting on the portion of the absorbent article positioned against the wearer's skin, thus increasing the chance for leakage. Such liquid transport layers are generally porous, water permeable fabrics, formed from synthetic fibers. The liquid transport layers may be formed from synthetic fibers alone, or a blend of synthetic and natural fiber, e.g. cellulosic fiber. Exemplary liquid transport layers include nonwovens, such as meltblown webs, spunbonded webs, and the like. Such nonwovens generally have a low density (0.03 to 0.1 g/cc) or high loft. Although a separate liquid transport layer can generally satisfactory perform the above-described functions, the incorporation of a separate acquisition layer in an absorbent article complicates the structure and requires additional manufacturing steps. This also necessarily increases the cost of the final product.
[0009] Accordingly, there remains a need in the art for more economically produced absorbent articles having improved absorptive capabilities. More specifically, there remains a need in the art for absorbent articles which include absorbent cores possessing increased acquisition rates. There is also a need in the art for absorbent cores providing intake performances that either decrease less dramatically upon saturation and repeated insults in comparison to conventional absorbent cores or, advantageously, increase with successive liquid insults.
BRIEF SUMMARY OF THE INVENTION
[0010] The present invention is directed to absorbent cores providing improved liquid transport performance, particularly increased acquisition rates, thus potentially eliminating the need for separate liquid transport layers. More specifically, Applicants have determined that the liquid transport properties of multi-layered absorbent cores may be improved, particularly over multiple insults, by including synthetic and/or regenerated staple fibers within one or more of the absorbent core layers, as indicated by increased acquisition rates and insult ratios in comparison to comparable absorbent cores without synthetic fiber. The synthetic and/or regenerated staple fibers can be incorporated into the absorbent core in the form of individualized fibers which are deposited as or within a layer during the absorbent core formation process, or the synthetic and/or regenerated staple fibers can be incorporated into the absorbent core in the form of a pre-formed nonwoven sheet.
[0011] The absorption performance of absorbent materials over time is commonly referred to as the “insult ratio”. The insult ratio as used herein refers to the acquisition rate after two or more insults divided by the initial acquisition rate. As further used herein, the term “second insult ratio” refers to the acquisition rate for the second insult divided by the initial acquisition rate. Similarly, as used herein the term “third insult ratio” refers to the acquisition rate for the third insult divided by the initial acquisition rate.
[0012] Applicants have determined that the beneficial acquisition rates of the present invention do not decrease as dramatically upon saturation and repeated insults as do conventional absorbent cores. Applicants have determined that the present invention generally provides second and third insult ratios of about 0.80 or higher. In fact, embodiments of the invention exhibit increased acquisition rates following saturation of the absorbent core and repeated liquid insults, i.e. second and third insult ratios greater than 1.0. Second and third insult ratios greater than 1.0 are altogether unexpected and heretofore unknown.
[0013] The invention generally provides absorbent cores that include (a) an innermost layer positioned towards the wearer that includes synthetic fiber in an amount effective to improve the liquid transport properties of said absorbent core; (b) at least one intermediate layer contiguous with the innermost layer and positioned away from the wearer, at least one of the intermediate layers including a mixture of cellulosic fiber and superabsorbent particles; and (c) an outermost layer containing cellulosic fiber that is contiguous with the intermediate layer and positioned furtherest from the wearer.
[0014] In alternative beneficial embodiments, the invention provides absorbent cores in which synthetic fiber is included within layers other than the innermost layer. For example, absorbent cores are provided that include (a) an innermost layer formed from cellulosic fiber positioned towards the wearer; (b) at least one intermediate layer contiguous with said innermost layer and positioned away from the wearer, at least one of the intermediate layers including synthetic fiber in an amount effective to improve the liquid transport properties of said absorbent core upon repeated liquid insults; and (c) an outermost layer formed from cellulosic fiber contiguous with the intermediate layer and positioned furtherest from the wearer.
[0015] The present invention further encompasses the methods by which to form absorbent cores including synthetic fiber and absorbent articles formed therefrom.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0016] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
[0017] [0017]FIG. 1 is a greatly enlarged, cross-sectional schematic view of one advantageous embodiment of the absorbent core of the present invention;
[0018] [0018]FIG. 2 is a greatly enlarged, cross-sectional schematic view of a second advantageous embodiment of the absorbent core of the present invention;
[0019] [0019]FIG. 3 is a simplified, diagrammatic view of an apparatus illustrating one advantageous process for making the improved absorbent core of the present invention;
[0020] [0020]FIG. 4 graphically illustrates the acquisition rate performance of conventional absorbent articles;
[0021] [0021]FIG. 5 graphically illustrates the acquisition rate performance of absorbent cores formed in accordance with beneficial embodiments of the present invention; and
[0022] [0022]FIG. 6 graphically illustrates the method by which the acquisition rate performance of the absorbent cores were determined.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
[0024] As illustrated in FIG. 1, the absorbent cores 8 of the present invention generally include a primary absorbent portion 10 , disposed upon an optional carrier layer 12 . The primary absorbent portion 10 typically includes at least three layers: an innermost layer 14 , positioned closest to the wearer (and the carrier layer 12 ); one or more intermediate layers 16 (a single intermediate layer is illustrated in FIG. 1); and an optional outermost layer 18 .
[0025] For the sake of clarity, the “layer count” will refer to the number of layers in the primary absorbent portion 10 , i.e., the carrier layer 12 will not be included. For example, in the “three” layered embodiment of the invention provided in FIG. 3, the “three” layers are present within the primary absorbent portion 10 , along with the carrier layer 12 . Further, although the absorbent core is referred to as containing “layers,” this term is merely used to facilitate discussion concerning the differing compositions which may be present in various regions within the absorbent core thickness. The absorbent cores of the present invention, although referred to as being formed from such “layers,” nevertheless provide unitary structures exhibiting cohesive properties throughout their thickness. Further, each “layer” is generally in either direct or indirect liquid communication with its adjacent layer(s).
[0026] The innermost layer 14 of the absorbent core 8 typically includes synthetic and/or regenerated fibers 20 , either alone or in combination with cellulosic fibers 22 and/or superabsorbent particles “SAP” 24 , as illustrated in FIG. 1. The intermediate layers 16 are normally formed from a mixture of cellulosic fibers 22 and SAP 24 , as further illustrated in FIG. 1. However, in aspects of the invention including multiple intermediate layers (as shown in FIG. 2) one or more of the intermediate layers 16 may also be formed from synthetic and/or regenerated fibers 20 , either alone or in combination with cellulosic fibers 22 and/or SAP 24 . In aspects of the invention in which one or more of the intermediate layers 16 includes synthetic and/or regenerated fibers 20 , the innermost layer 14 may optionally be formed entirely from cellulosic fibers 22 , either alone or in combination with SAP 24 . As further shown in FIG. 1, the outermost layer 18 of the absorbent core 8 is typically formed entirely of cellulosic fiber 22 .
[0027] Any known synthetic or regenerated fiber 20 known in the art may be incorporated into the absorbent cores 8 of the present invention, whether in the form individualized fibers or as a pre-formed nonwoven sheet. Advantageously, the synthetic fiber 24 is a thermoplastic fiber exhibiting a melting temperature of greater than about 170° C. Exemplary synthetic fibers include polyalkylene terephthalates, such as polyethylene terephthalate (“PET”); polyolefins, such as polyethylene (“PE”) and polypropylene (“PP”); acrylic; polyamides, such as nylon; and blends thereof. Exemplary regenerated fibers include rayon and acetate In advantageous embodiments, the synthetic fiber is polyethylene terephthalate. For the sake of brevity and clarity, the term “synthetic fiber” will be used hereinafter to refer to both synthetic and regenerated fibers.
[0028] The synthetic fibers of the invention may be included in the absorbent core in their natural state or may be hydrophillically modified. For example, the synthetic fibers may have either carboxyl or hydroxyl functionality grafted or coated onto its surface. The synthetic fiber may further have any known geometry. For example, the synthetic fiber may be either hollow or solid. The synthetic fiber may further have any cross-section known in the art of fiber formation. For example, the synthetic fiber may have a cross-section known to impart greater stiffness in comparison to circular fiber, such as quadralobal cross-sections or the like.
[0029] The synthetic fibers typically have a denier ranging from about 3 to 25 dpf, such as a denier of 3, 6, 9 or 15 dpf. (The term “dpf” refers to the weight in grams of 9,000 meters of a fiber.) The synthetic fibers are typically staple fibers. The synthetic fiber generally has a staple length of greater than about 2 mm, such as a nominal staple length ranging from about 2 to about 20 mm. In advantageous embodiments, synthetic fibers having a nominal staple length of about 6 mm are employed. As known in the art, staple fibers are typically crimped. In the instant invention, the synthetic fiber may be highly crimped. For example, the synthetic fibers may possess about 1 to 20 crimps/inch or greater.
[0030] The synthetic fibers may be present within the primary absorbent portion 10 in amounts ranging from about 10 to 100 gsm. For example, the synthetic fiber may be present in an absorbent core 8 having a basis weight of about 450 gsm in amounts ranging from about 10 to 100 gsm. In one advantageous embodiment, the synthetic fiber is present within an absorbent core having a basis weight of about 450 gsm in an amount of about 60 gsm. In further advantageous embodiments the synthetic fiber may be present in within absorbent cores having a basis weight of about 250 gsm in amounts ranging from about 10 to 60 gsm, such as a 250 gsm absorbent core containing 40 gsm synthetic fiber.
[0031] Considered on a relative weight basis, the synthetic fiber may thus beneficially be present with the absorbent core 8 in amounts ranging from about 2 to 30 weight percent, based on the weight of the absorbent core. (As used herein, the term “based on the weight of the absorbent core” may be abbreviated as “boc”). For example, the synthetic fiber may be present in the absorbent core in amounts ranging from about 13 to 16 weight percent, boc.
[0032] The total amount of synthetic fiber 20 may advantageously be present within the innermost layer 14 , as shown in FIG. 1. In further beneficial embodiments, the synthetic fiber 20 may be portioned amongst the innermost layer and one or more intermediate layers 16 . For example, one half of the total amount of the synthetic fiber 20 may be in the innermost layer 14 and the remaining half may be portioned amongst one or more intermediate layers 16 . In alternative advantageous embodiments, the total amount of synthetic fiber may be present in the intermediate layer or a combination of the intermediate and outer layers, as well. Surprisingly, alternative embodiments in which synthetic fiber is present within the intermediate or intermediate and outer layers but not within the innermost layer similarly provide beneficial intake performances after repeated insults.
[0033] In advantageous embodiments, the synthetic-fiber is PET. For example, one or more layers within the primary absorbent portion 10 may include PET fibers having a nominal 6 millimeter staple length and about 15 dpf in a highly crimped condition. Absorbent materials made in accordance with the present invention may also include PET fibers having a nominal staple length of 6 millimeters and 9 dpf in a highly crimped condition, as well as PET fibers having nominal length of 6 millimeters and 3 dpf in a highly crimped condition. In beneficial aspects of these embodiments, PET fiber is included within the innermost layer 14 of the primary absorbent portion 10 . In further advantageous embodiments, PET fiber is included within the innermost layer 14 and at least one intermediate layer 16 . In alternative embodiments, PET fiber is included within either (a) at least one intermediate layer 16 and the outermost layer 18 or (b) at least one intermediate layer 16 , but not within the innermost layer 14 . The PET fiber could have any known geometry, for example, the PET fiber could be either a hollow fiber or a solid fiber.
[0034] The present invention also contemplates the use of multicomponent synthetic fibers in one or more layers of the primary absorbent portion 10 . Exemplary multicomponent fibers include bicomponent fibers, such as bicomponent PP/PE fiber or PP/PET fibers. One example of PP/PE bicomponent fiber suitable for use in the present invention includes a polypropylene core and a polyethylene sheath and has a nominal staple length of 6 millimeters and 10 to 12 denier. An exemplary PP/PET fiber includes a PET core and PP sheath with a nominal staple length of about 6 mm and 12 dpf.
[0035] The synthetic fibers described above can be incorporated into the absorbent core in the form of individualized fibers which are deposited so as to form at least a portion of a layer during the absorbent core formation process. In alternative advantageous embodiments, the synthetic staple fibers described above can be incorporated into the absorbent core in the form of a pre-formed nonwoven sheet or web. As used herein, the term “sheet” is used interchangeably with the term “web.” Any nonwoven construction known in the art may be used as the pre-formed web. Suitable pre-formed nonwoven webs are typically formed from fiber having a denier ranging from about 3 to 25 dpf and fiber lengths ranging from about 2 to 20 mm. Pre-formed nonwoven sheets suitable for use in the invention also generally exhibit a basis weight ranging from about 20 to 80 gsm. Any of the bonding technologies well known in the art, including but not limited to through-air-bonding (“TAB”), spunbonding, chemical bonding, thermal point bonding, needle punching and hydroentanglement, may be used to form the pre-formed nonwoven web. One exemplary suitable material is a TAB nonwoven sheet commercially available as Dry-web T-9, a 40 gsm basis weight web available from Libeltex N. V. of Meulebeke, Belgium. The pre-formed nonwoven sheets may generally form the innermost layer and/or one or more of the intermediate layers. The pre-formed sheet may generally form from about 4 to 32 weight percent of the absorbent core, such as from about 8 to 16 weight percent of the absorbent core.
[0036] Cellulosic fibers 22 are included in at least the outermost layer 18 and one or more of the intermediate layers 16 . Cellulosic fibers 22 may optionally be included in the innermost layer 14 , as well. Cellulosic fibers that can be used in the absorbent articles of the present invention are well known in the art and include fiber derived from wood pulp, cotton, flax, and peat moss. In advantageous embodiments, cellulosic fiber derived from wood pulp is employed. Wood pulp fibers can be obtained from mechanical or chemi-mechanical, sulfite, kraft, pulping reject materials, organic solvent pulps, etc. Both softwood and hardwood species are useful. Softwood pulps are preferred. It is not generally necessary to treat cellulosic fibers with chemical debonding agents, cross-linking agents and the like for use in the primary absorbent portion, although such treatments may be employed.
[0037] Advantageously, the wood pulp is prepared using a process that reduces the lignin content of the wood. For example, the lignin content of the pulp may be less than about 16 percent, such as a lignin content of less than about 10 percent. Beneficially, the lignin content is less than about 5 percent, such as a lignin content of less than about 1 percent. As is well known in the art, lignin content is calculated from the Kappa value of the pulp. The Kappa value is determined using a standard, well known test procedure TAPPI Test 265-cm 85. The Kappa value of a variety of pulps was measured and the lignin content calculated using the TAPPI Test 265-cm 85. The cellulosic fibers of the present invention may advantageously be derived from wood pulp having a Kappa value of less than about 100. Beneficially, the Kappa value is less than about 75, such as a Kappa value of less than 50 and beneficially less than 25, 10 or 2.5.
[0038] In one advantageous embodiment, the cellulosic fiber is derived solely from standard untreated cellulose. In further beneficial embodiments, the cellulosic fiber may be a mixture of standard untreated cellulosic fibers and alkaline treated cellulosic fibers, such as cold caustic treated (“CCT”) cellulosic fibers. The weight ratio of standard untreated cellulosic fiber to alkaline treated cellulosic fiber may beneficially range from about 0:100 to 100:0, such as 0.5:1 to 10:1. For example, in advantageous embodiments the weight ratio of standard untreated cellulosic fiber to alkaline treated cellulosic fiber may range from about 1.2:1 to 1.29:1. Considered differently, a mixture of standard untreated cellulosic fibers and alkaline treated cellulosic fibers may be employed in which the untreated cellulosic fibers are present in an amount ranging from about 15 to 30 weight percent, bol, such as from about 19 to 27 weight percent, bol, while the alkaline treated cellulosic fibers may be present in amounts ranging from about 15 to 25 weight percent, bol, such as from about 17 to 22 weight percent, bol.
[0039] Alkaline treatments for cellulosic fiber, particularly wood pulp fibers, are well known in the art. By way of example, treating wood pulp with liquid ammonia is known to decrease relative crystallinity and to increase the fiber curl value. Alternatively, cold caustic treatment of wood pulp also increases fiber curl and decreases relative crystallinity.
[0040] A description of absorbent cores containing cold caustic treated cellulosic fibers is described in commonly owned U.S. Pat. Nos. 5,866,242 and 5,916,670, both of which are incorporated in their entirety herein by reference thereto. Cold caustic treated cellulosic fibers are commercially available. Exemplary commercially available cold caustic treated cellulosic fiber is POROSANIER-BAT™ fiber from Rayonier, Inc. of Jesup, Ga.
[0041] Briefly, in cold caustic treatment a caustic treatment is typically carried out at a temperature less than about 60° C., advantageously at a temperature less than 50° C., such as a temperature between about 10° C. and about 40° C. One exemplary alkali metal salt solution is a sodium hydroxide solution newly made up or as a solution by-product in a pulp or paper mill operation, e.g., hermicaustic white liquor, oxidized white liquor and the like. Other alkali metals such as ammonium hydroxide and potassium hydroxide and the like can be employed. However, from a cost standpoint, sodium hydroxide may advantageously be utilized. The concentration of alkali metal salts is typically in a range from about 2 to about 25 weight percent of the solution, and preferably from about 6 to about 18 weight percent. Pulps for high rate, fast absorbing applications are generally treated with alkali metal salt concentrations from about 10 to about 18 weight percent. In alternative embodiments, methods other than alkaline treatment may be used to produce wood pulp fiber exhibiting lower crystallinity and increased curl. For example, flash dried or chemically cross-linked wood pulp may be employed.
[0042] As noted above, cellulosic fiber 22 may generally be present in several of the layers within the primary absorbent portion 10 , including the outermost layer 18 , one or more intermediate layers 16 and, optionally, the innermost layer 14 . The outermost layer 18 may contain cellulosic fiber in amounts ranging from about 20 to 100 wt %, based on the weight of the layer. (As used herein, the term “based on the weight of the layer” may be abbreviated “bol”.) In beneficial embodiments, the outermost layer 18 may be formed entirely of cellulosic fiber. Cellulosic fiber 22 may be present within one or more of the intermediate layers 16 in amounts ranging from about 0 to 100 weight percent, bol, such as in amounts ranging from about 20 to 100 weight percent, bol. In embodiments including more than one intermediate layer 16 , the cellulosic fiber 22 may be equally portioned amongst the layers. Alternatively, the cellulosic fiber may be present in greater amounts in intermediate layers positioned closest to the wearer. Cellulosic fiber 22 may also be present within the innermost layer 14 , in amounts of up to about 50 weight percent, bol. In one beneficial embodiment, cellulosic fiber 22 is included in the innermost layer 14 in an amount of about 29 weight percent, bol. In the alternative embodiments of the invention in which one or more pre-formed nonwoven sheets is used to form one or more of the layers, the amount of cellulosic fiber within a given pre-formed sheet range from about zero to 90 weight percent, bol.
[0043] Superabsorbent particles (“SAP”) 24 may be included within one or more of the intermediate layers 16 and, optionally, the innermost layer 14 . As used herein, the term “superabsorbent particle” includes any substantially water-insoluble polymeric material capable of absorbing large quantities of fluid in relation to its weight. The SAP can be in the form of particulate matter, flakes, fibers and the like. Exemplary particulate forms include granules, pulverized particles, spheres, aggregates and agglomerates. Exemplary SAP include polyacrylamides, polyvinyl alcohol, polyacrylates, various grafted starches, and the like. In advantageous embodiments, the superabsorbent materials include salts of crosslinked polyacrylic acid such as sodium polyacrylate. Superabsorbent materials are commercially available. Exemplary commercially available SAPs include SXM 880 and SXM 9200, both of which are available from Stockhausen GmbH, Krefeld, Germany.
[0044] The total amount of SAP present within the absorbent core may range from about 10 to 60 weight percent based on the weight of the absorbent core. For example, the SAP may be present in the absorbent core in an amount ranging from about 25 to 60 weight percent, such as in an amount of about 55 weight percent. SAP may be beneficially incorporated into the innermost layer 14 , in amounts ranging up to about 70 weight percent, bol, such as from about 25 to 65 weight percent, bol. In one advantageous embodiment, SAP may be included in the innermost layer 14 in an amount of about 29 weight percent, bol. SAP may be beneficially incorporated into the intermediate layer 16 in amounts ranging from about 0 to 85 weight percent, such as from about 5 to 67 weight percent, beneficially about 39 weight percent, bol.
[0045] The concentration of superabsorbent particles is generally uniform along the length of the instant absorbent cores. However, in beneficial embodiments various SAP concentration gradients may be employed through the thickness of the absorbent core. For example, in embodiments directed to multiple intermediate layers, the total amount of SAP is generally portioned amongst two or more intermediate layers. For example, the SAP may be divided equally amongst several intermediate layers. Alternatively, the SAP may be present in lesser amounts in intermediate layers positioned closest to the wearer. In further alternative embodiments, the total amount of SAP may be distributed amongst several intermediate layers in a parabolic fashion.
[0046] A number of exemplary materials may be employed as the carrier layer. The carrier layer 12 may be, for example, either a spunbond or melt-blown non-woven consisting of natural or synthetic fibers.
[0047] Tissue may also be advantageously used as the carrier layer 12 . Suitable tissue materials for use as a carrier layer 12 in absorbent cores 8 are well known to those of ordinary skill in the art. Beneficially, such tissue is made of bleached wood pulp and has an air permeability of about 273-300 CFM (cubic feet minute). The tensile strength of the tissue may be such that it retains integrity during formation and other processing of the absorbent material. Suitable MD (machine direction) and CD (cross direction) tensile strengths, expressed in newtons/meter, are about 100-130 and 40-60, respectively. The tissue may be a crepe tissue having a sufficient number of crepes per inch to allow a machine direction elongation of between 20 and 35 percent (as determined by the SCAN P44:81 test method). The basis weight of the carrier layer 22 is typically between about 15 and about 20 g/m 2 , but could be more or less. Tissue for use in air-laying absorbent materials are commercially available (e.g., from Cellu Tissue Corporation, 2 Forbes Street, East Hartford, Conn. 06108, U.S.A., and from Duni A B, Sweden). In an alternative embodiment, a top carrier layer (not shown in FIG. 1) may further be disposed on the outermost layer 18 . Such a top carrier layer may be formed from the same or different material than the bottom carrier layer 12 .
[0048] The innermost layer 14 may compose about 3 to 20 weight percent of the absorbent core. For example, the innermost layer 14 may constitute about 7 to 16 weight percent of the absorbent core. The intermediate layer 16 may compose about 20 to 90 weight percent of the absorbent core. For example, the intermediate layer 16 may constitute about 69 to 92 weight percent of the absorbent core. The outermost layer 18 may compose about 0 to 20 weight percent of the absorbent core, such as from about 2 to 15 weight percent of the absorbent core. For example, the outermost layer 18 may constitute about 4 weight percent of the absorbent core. The carrier layer 22 may compose from about 1 to 10 weight percent of the absorbent core, such as from about 3 to 8 weight percent of the absorbent core.
[0049] [0049]FIG. 2 illustrates a beneficial embodiment in which the absorbent core 8 is formed from six (6) layers. In such six layer constructions, the innermost layer 14 may generally comprise from about 5 to 33 weight percent of the absorbent core. In advantageous aspects of these embodiments, the innermost layer 14 may comprise between 7 to 16 weight percent of the absorbent core, particularly about 7 weight percent of the absorbent core.
[0050] As shown in FIG. 2, the innermost layer 14 typically includes synthetic fiber 20 . The synthetic fiber 20 may advantageously be present within the innermost layer 14 in amounts ranging from about 20 to 80 gsm, for absorbent cores ranging in basis weight from 250 to 450 gsm. On a relative weight basis, the synthetic fiber 20 may generally be present within the innermost layer 14 in amounts ranging from about 20 to 100 weight percent bol, such as in amounts ranging from about 43 to 100 weight percent bol, particularly in an amount of about 100 weight percent bol.
[0051] Advantageously, the innermost layer 14 may be formed from a combination of synthetic fiber, cellulosic fiber and optional SAP (not shown in FIG. 2). In such advantageous embodiments, the cellulosic fiber 22 and SAP 24 may each independently be included in the innermost layer 14 in amounts of up to about 50 weight percent bol, such as an amount of about 29 weight percent bol.
[0052] The construction illustrated in FIG. 2 includes a plurality of intermediate layers 16 , designated 16 a through 16 d. Layers 16 a, 16 c and 16 d are typically formed from a mixture of cellulosic fiber and SAP.
[0053] The first intermediate layer 16 a may constitute from about 0 to 50 weight percent of the absorbent core, such as from about 5 to 50 weight percent of the absorbent core. Advantageously, the first intermediate layer 16 a comprises from about 0 to 26 weight percent of the absorbent core, such as about 14 weight percent of the absorbent core.
[0054] The first intermediate layer 16 a may contain cellulosic fiber 22 in amounts ranging from about 15 to 100 weight percent bol, advantageously in an amount ranging from about 33 to 100 weight percent bol. In advantageous embodiments, the first intermediate layer 16 a includes cellulosic fiber 22 in an amount of about 61 weight percent, bol. The first intermediate layer 16 a may further contain SAP 24 in amounts ranging from about 0 to 85 weight percent bol, such as in amounts ranging from 5 to 67 weight percent bol. In beneficial embodiments, the first intermediate layer 16 a includes SAP 24 in an amount of about 39 weight percent bol. The first intermediate layer 16 a may also contain synthetic fiber in amounts of up to 50 weight percent, bol, such as about 43 weight percent, bol.
[0055] The third and fourth intermediate layers 16 c and 16 d may each independently comprise from about 12 to 70 weight percent of the absorbent core. Advantageously, the third and fourth intermediate layers 16 c and 16 d may each independently comprise from about 24 to 35 weight percent of the absorbent core. In beneficial embodiments, intermediate layer 16 c may comprise 32 weight percent of the absorbent core and intermediate layer 16 d may comprise 33 weight percent of the absorbent core.
[0056] The third and fourth intermediate layers 16 c and 16 d generally contain cellulosic fiber 22 in amounts ranging independently from about 10 to 66 weight percent bol, such as an amount ranging from about 20 to 33 weight percent bol. In advantageous embodiments, the third intermediate layer 16 c includes cellulosic fiber in an amount of about 23 weight percent bol and the fourth intermediate layer 16 d includes cellulosic fiber in an amount of about 22 weight percent bol.
[0057] The third and fourth intermediate layers 16 c and 16 d may further contain SAP 24 in amounts ranging independently from about 33 to about 90 weight percent bol, such as amounts ranging from about 67 to 80 weight percent bol. In beneficial embodiments, the third intermediate layer 16 c includes SAP in an amount of about 77 weight percent bol and fourth intermediate layer 16 d includes SAP in an amount of about 78 weight percent bol.
[0058] The third and fourth intermediate layers 16 c and 16 d may further independently contain synthetic fiber in amounts ranging from about 0 to 100 weight percent, bol, such as from about 5 to 100 weight percent, bol. In advantageous embodiments, the third and fourth intermediate layers 16 c and 16 d may independently contain from about 30 to 40 weight percent synthetic fiber, bol, such as from about 33 to 38 weight percent synthetic fiber, bol.
[0059] The second intermediate layer 16 b, which is an optional layer, may be formed from synthetic fiber 20 , either alone or in combination with cellulosic fiber 22 and/or SAP 24 . In alternative beneficial embodiments, the second intermediate layer 16 b may be formed from cellulosic fiber 22 , alone or in combination with SAP 24 , i.e. without the inclusion of synthetic fiber 20 .
[0060] The second intermediate layer 16 b may comprise from about 0 to 33 weight percent of the absorbent core. Advantageously, the second intermediate layer 16 b may to comprise from about 0 to 16 weight percent of the absorbent core. In one beneficial embodiment, the second intermediate layer 16 b may comprise 7 weight percent of the absorbent core.
[0061] The second intermediate layer 16 b may contain synthetic fiber 20 in amounts ranging from about 0 to 100 weight percent bol. For example, the second intermediate layer 16 b may contain synthetic fiber 20 in an amount of about 20 to 100 weight percent bol, such as an amount of about 100 weight percent, bol.
[0062] The second intermediate layer 16 b may further include cellulosic fiber 22 and/or SAP 24 in amounts ranging from about 0 to 60 weight percent bol, such amounts ranging from 0 to 29 weight percent, bol.
[0063] The outermost layer 18 may generally comprise from about 0 to 10 weight percent of the absorbent core. In advantageous aspects of these embodiments, the outermost layer 14 may comprise about 4 weight percent of the absorbent core. The outermost layer 18 may advantageously contain from about 20 to 100 weight percent bol of cellulosic fiber 22 . In beneficial embodiments, the outermost layer 18 includes about 100 weight percent cellulosic fiber 22 .
[0064] The absorbent core 8 generally exhibits a basis weight ranging from about 100 to 800 gsm. As known in the art, higher basis weight constructions, such as 450 gsm constructions, are generally well suited for diaper applications. Lower basis weight constructions, such as 250 gsm constructions, may be preferable for adult incontinence and feminine care applications.
[0065] The moisture content of the absorbent core 8 after equilibration with the ambient atmosphere is generally less than about 10% (by weight of the total material weight), such as less than about 8%, and beneficially lies in the range of between about 1% and 8%. A typical thickness of the absorbent core 8 is between 0.5 mm and 2.5 mm.
[0066] The density of the absorbent core 8 is generally greater than or equal to about 0.18 g/cm 3 . The density of the absorbent core 8 advantageously ranges from between about 0.2 and 0.5 g/cm 3 such as from about 0.25 to 0.40 g/cm 3 . The density of conventional absorbent cores is typically much lower than the present absorbent cores. For example, U.S. Pat. No. 5,913,850 to D'Alessio et al. notes the use of absorbent cores having a bulkiness of 20 cc/g, translating to a density of 0.05 g/cm 3 . Such lower density conventional cores would be expected to provide greater void volume and hence better liquid transport properties. It is thus altogether surprising that the instant absorbent cores, generally exhibiting higher densities than conventional absorbent cores, would provide advantageous liquid transport properties in comparison to conventional cores, particularly improved second and/or third insult ratios.
[0067] Surprisingly, by carefully tailoring the components within the various layers of the absorbent core, Applicants have produced absorbent cores exhibiting second, and even third, insult ratios of greater than about 0.8, and advantageously greater than about 0.90. In contrast, conventional absorbent cores typically provide insult ratios of less than 0.60. Applicants have further found that absorbent cores formed in accordance with the invention can exhibit second insult ratios of greater than about 1.0, such as ratios of greater than about 1.2 or 1.5. The beneficial absorption properties of the invention are provided for the third insult ratio, as well. More specifically, absorbent cores formed in accordance with the invention can similarly exhibit third insult ratios of greater than 1.0, such as a ratio of 1.2 or more, or even 1.3 or more. Insult ratios of greater than 1.0 indicate that the acquisition rate of later insults was higher than the acquisition rate of the initial insult. Such behavior is altogether surprising and has heretofore been unknown. The absorbent cores of the invention also advantageously provide initial acquisition rates, also referred to as intake rates, of greater than about 0.70 ml/sec, such as initial acquisition rates of greater than 0.9 or 1.0 ml/sec.
[0068] The instant absorbent cores may be formed by any means known in the art. For example, the absorbent cores may be produced by manufacturing processes which employ forming wires, screens or belts, such as air laying or wet laying techniques. FIG. 3 schematically illustrates an advantageous air laying process by which to produce absorbent core in accordance with the invention. More specifically, FIG. 3 illustrates a process by which to air lay a six layer construction (such as the construction illustrated in FIG. 2). Air laying is commonly used in conjunction with wood pulp. To air lay a layer of wood pulp, incoming wood pulp is initially separated into individualized wood fibers, using a hammer mill or the like (not shown). In general, the individualized wood fibers are transported through a forming head station 65 and deposited by vacuum onto a forming wire 60 .
[0069] The process permits the optional incorporation of a bottom carrier layer 62 in the absorbent material (e.g., carrier layer 12 in the absorbent material described above with reference to FIGS. 1 and 2, respectively). To this end, as shown in FIG. 3, a carrier web 62 is unwound from a carrier web roll 64 and directed over the endless forming wire 60 . A series of forming heads in a forming head station 65 are provided over the endless forming wire 60 . The illustrated forming head station 65 includes first through sixth forming heads 71 and 76 . In alternative embodiments, a lesser or greater number of forming heads may be provided. For example, the station may include as few as 2 forming heads.
[0070] In advantageous embodiments, the first forming head 71 discharges synthetic fiber alone. Alternatively, the first forming head 71 may discharge a blend of synthetic fiber and cellulosic fiber, optionally containing SAP. In further alternative embodiments that include synthetic fiber within one or more of the intermediate layers, the first forming head 71 may discharge cellulosic fiber, either alone or in combination with SAP. The intermediate forming heads 72 through 75 typically discharge cellulosic fiber, beneficially in combination with SAP. In one beneficial embodiment, an intermediate forming head, such as forming head 73 , discharges synthetic fiber in lieu of or in addition to cellulosic fiber and/or SAP. In an alternative beneficial embodiment, one or more of the intermediate forming heads, such as forming head 73 , stands idle and does not deposit a layer of fiber upon the intermediate construction. Advantageously, the final forming head, illustrated as forming head 76 in FIG. 3, discharges only cellulosic fiber without discharging synthetic fibers or SAP.
[0071] The blending and distribution of the various components, i.e., the synthetic fiber, cellulosic fiber and SAP, can be controlled separately for each forming head. The forming head 71 is connected with a blending system 81 , and the forming head 72 is connected with a blending system 82 , and so on, through forming head 76 , connected with a blending system 86 . The pulp fibers, synthetic polymer fibers, and superabsorbent granules or particles can be blended in the blending systems and conveyed pneumatically into the appropriate forming heads. Alternatively, the pulp fibers, synthetic polymer fibers, and superabsorbent granules or particles can be conveyed separately to the appropriate forming heads and then blended together in the forming heads. Controlled air circulation and winged agitators in each blending system may be used to produce a substantially uniform mixture and distribution of the pulp and superabsorbent particles and/or synthetic polymer fibers.
[0072] The material from each forming head is deposited, preferably with vacuum assist, as a loose, uncompacted, layer superposed on the preceeding layer. The first layer, deposited by forming head 71 , is advantageously deposited directly on the carrier layer 62 (or, alternatively, directly onto the endless screen 60 ). Although not wishing to be bound by theory, Applicants hypothesize that the carrier layer 62 provides a natural barrier to hold the synthetic fiber in position, thereby avoiding dust formation. Applicants further hypothesize that the outer layers of the absorbent core, e.g., the layers produced by forming heads 72 through 76 , provide a similar function. Thus, the synthetic fiber deposited by the initial forming head 71 resides in a containment means defined by the carrier layer 62 and subsequent absorbent core layers issuing from forming heads 72 - 76 .
[0073] In alternative advantageous embodiments of the invention (not shown), one or more pre-formed nonwoven sheets, generally in the form of roll goods, can be introduced between any of the forming heads 71 through 76 or between the carrier layer 12 and the first forming head 71 . In such alternative advantageous embodiments employing preformed nonwoven sheet, the integrity of the pre-formed sheet prevents the synthetic fibers from dusting.
[0074] In advantageous embodiments, the carrier layer 62 may be subjected to an optional water spray 90 provided by nozzle 92 . The water spray 90 is believed to promote bonding between the carrier layer 62 and the cellulosic fibers present within the absorbent core. In further beneficial aspects of this embodiment, SAP is included within the synthetic fiber deposited by the first forming head 71 , to further enhance bonding between the carrier layer 62 and cellulosic fibers during product usage.
[0075] The loose layers of absorbent core are then conveyed, preferably with the help of a conventional vacuum transfer device 100 , from the end of the endless screen 60 through a first set of compaction rolls 110 and 112 and then through calendar rolls. The calendar rolls include an upper roll 121 and a lower roll 122 which compress or compact the absorbent core to form an increased density web.
[0076] In one advantageous embodiment, the upper roll 121 is typically a steel roll, and the lower roll 122 is typically a steel roll. In beneficial aspects of the invention, the upper roll 121 has an embossing pattern surface, and the lower roll 122 has a smooth surface. In some applications it may be desirable to reverse the orientation of the web through the rolls so that the embossing roll contacts the carrier layer 62 of the web. In other applications, it may be desirable to provide both the upper and lower rolls 121 and 122 with an embossing pattern surface.
[0077] The weight of the upper roll 121 bears on the web. Additional force may be provided with conventional hydraulic actuators (not illustrated) acting on the axle of the roll 121 . In one form of the invention, the web is compacted between the rolls 121 and 122 under a load of between about 28 and about 400 newtons per millimeter of transverse web width (160-2284 pounds force per inch of transverse web width).
[0078] The processing line is preferably run at a line speed of between about 30 meters per minute and about 300 meters per minute. Either one or both of rolls 121 and 122 may be heated. In advantageous aspects, each of rolls 121 and 122 is heated, in beneficial embodiments, to at least about 120° C. In one advantageous embodiment, the calendar rolls 121 , 122 are heated to a temperature ranging from about 120 to 170° C. The temperature of the rolls 121 and 122 should be sufficient to facilitate the establishment of hydrogen bonding of the pulp fibers to each other, as well as of the tissue layer (if any) to the pulp fibers, so as to increase the strength and integrity of the finished absorbent core. The calendaring of the present invention provides a finished absorbent core with exceptional strength and resistance to shake-out of synthetic fiber and superabsorbent material.
[0079] The temperature of each roll is dependent upon the line speed and type of synthetic polymer fiber that is employed. It has been found that the process of the present invention can be operated to provide absorbent cores which, while having improved fluid acquisition properties imparted by the synthetic fibers, still has a relatively low Gurley Stiffness and is therefore soft and supple.
[0080] According to preferred forms of the invention, the temperatures of the rolls 121 and 122 are not sufficient to cause melting of the surface of the synthetic fibers incorporated in the web at the particular line speed and compaction load that are employed. By avoiding the melting of the surfaces of the synthetic polymer fibers, the process minimizes the formation of thermal bonds that would increase rigidity and stiffness of the web.
[0081] Upon leaving the rolls 121 and 122 , the web contains very little moisture (e.g., 1%-8% moisture based on the total weight of the web). The compressed and densified web is wound into a roll 130 using conventional winding equipment. The web moisture content will typically increase as the web reaches equilibrium with the ambient atmosphere, but it is desirable that the moisture content not be too high--advantageously the web moisture content ranges between about 1% and about 8% of the total weight of the web.
[0082] The high density absorbent cores made by the process of the present invention, typically containing synthetic fibers within their innermost layer, have good fluid acquisition and absorptive capabilities, are surprisingly and unexpectedly soft and supple, and yet are relatively strong with good integrity, both wet and dry. The absorbent cores can be prepared by the process of the present invention over a wide range of basis weights without adversely affecting their softness or strength.
[0083] The invention will be further illustrated by the following non-limiting examples.
EXAMPLES
[0084] Examples 1 through 9 in accordance with present invention and Comparative Examples 1 through 8 were produced using the layer compositions provided as Recipes A through J below. The specific recipes used for each of the Examples 1 through 9 and Comparative Examples 1 through 8 are noted in Table 1. The samples were produced using 17 gsm tissue as the carrier layer, commercially available as designated grade 3008 from Cellu Tissue Corporation. The SAP, both the SXM 880 and the SXM 9200 were obtained from Stockhansen GmbH, Krefeld, Germany. The PET was hydrophillically treated fiber having a nominal staple length of 6 mm and denier and geometries described in Table 11. The PET was procured from KOSA of Charlotte, N.C. The cellulose fiber was untreated pulp fiber identified as RAYFLOC-J-LD pulp fiber, commercially available from Rayonier Inc. of Jesup, Ga.
[0085] The samples were prepared using the process described in conjunction with FIG. 3, with FH1 through FH6 corresponding to forming heads 71 through 76 , respectively. Water was applied to the carrier sheet prior to calendaring in an amount of about 1 weight percent boc for samples having a basis weight about 250 gsm and in an amount of about 7 weight percent boc for all other samples.
% in Each Forming Head % of total SAP PET Pulp basis weight RECIPE A Tissue 4% FH 1 0% 0% 100% 13% FH 2 67% 0% 33% 26% FH 3 0% 0% 0% 0% FH 4 73% 0% 27% 26% FH 5 73% 0% 27% 26% FH 6 0% 0% 100% 4% RECIPE B Tissue 4% FH 1 0% 100% 0% 13% FH 2 67% 0% 33% 26% FH 3 0% 0% 0% 0% FH 4 73% 0% 27% 26% FH 5 73% 0% 27% 26% FH 6 0% 0% 100% 4% RECIPE C Tissue 4% FH 1 0% 0% 100% 13% FH 2 0% 0% 100% 9% FH 3 0% 0% 0% 0% FH 4 80% 0% 20% 35% FH 5 80% 0% 20% 35% FH 6 0% 0% 100% 4% RECIPE D Tissue 4% FH 1 0% 100% 0% 13% FH 2 0% 0% 100% 9% FH 3 0% 0% 0% 0% FH 4 80% 0% 20% 35% FH 5 80% 0% 20% 35% FH 6 0% 0% 100% 4% RECIPE E Tissue 7% FH 1 0% 0% 100% 16% FH 2 38% 0% 62% 21% FH 3 0% 0% 0% 0% FH 4 67% 0% 33% 24% FH 5 67% 0% 33% 24% FH 6 0% 0% 100% 8% RECIPE F Tissue 7% FH 1 0% 100% 0% 16% FH 2 38% 0% 62% 21% FH 3 0% 0% 0% 0% FH 4 67% 0% 33% 24% FH 5 67% 0% 33% 24% FH 6 0% 0% 100% 8% RECIPE G Tissue 4% FH 1 0% 100% 0% 7% FH 2 39% 0% 61% 14% FH 3 0% 100% 0% 7% FH 4 77% 0% 23% 32% FH 5 78% 0% 22% 33% FH 6 0% 0% 100% 4% RECIPE H Tissue 4% FH 1 0% 0% 100% 7% FH 2 39% 0% 61% 14% FH 3 0% 0% 100% 7% FH 4 77% 0% 23% 32% FH 5 78% 0% 22% 33% FH 6 0% 0% 100% 4% RECIPE I Tissue 4% FH 1 29% 43% 29% 16% FH 2 0% 0% 0% 0% FH 3 29% 43% 29% 16% FH 4 77% 0% 23% 30% FH 5 77% 0% 23% 30% FH 6 0% 0% 100% 4% RECIPE J Tissue 4% FH 1 29% 0% 71% 16% FH 2 0% 0% 0% 0% FH 3 29% 0% 71% 16% FH 4 77% 0% 23% 30% FH 5 77% 0% 23% 30% FH 6 0% 0% 100% 4%
[0086] Table 1 provides both the recipes for and the properties exhibited by Examples 1 through 11 and Comparative Examples 1 through 8. The basis weight and density of each sample were determined using methods well known in the art. The acquisition, or intake, rates were determined using a standard intake rate test that measures the amount of time taken for a liquid to disappear from the surface of a sample. The apparatus used to determine the acquisition rate is schematically illustrated in FIG. 6. FIG. 6A provides an exploded view of the apparatus while FIG. 6B provides an illustration of the apparatus in use. As shown, the intake rate apparatus generally includes a 3″ by 6″ elevated anvil 150 and a top platen 152 . The top platen 152 , weighing 880 g, has a 2 inch hole connected to a tube 154 . The top platen 152 is designed to apply a 0.1 psi load to the sample 156 . To perform the intake rate test, a 300 mm by 110 mm sample 156 is placed between the elevated anvil 150 and the top platen 152 . An initial liquid insult 158 , i.e. approximately 100 ml of a 0.9% NaCl solution, is then introduced into the tube 154 and the time for the solution to disappear into the sample 156 is measured. The sample 156 is allowed to sit in the apparatus for 5 minutes and the insult/measurement procedure is repeated. In total, the insult/measurement procedure is repeated three times.
TABLE 1 Insult Insult Basis 2/1 3/1 Sample Recipe PET SAP Weight Density Intake Rate, mL/s Rate Rate ID ID Type Type gsm g/cc Insult 1 Insult 2 Insult 3 Ratio Ratio Comp. A SXM 447 0.37 0.93 0.45 0.42 0.48 0.45 Ex. 1 880 Ex. 1 B 15 df, SXM 436 0.29 1.14 0.91 0.85 0.80 0.75 solid 880 Comp. C SXM 416 0.33 0.81 0.44 0.45 0.55 0.56 Ex. 2 880 Ex 2 D 15 df, SXM 411 0.26 1.32 1.02 0.92 0.78 0.70 solid 880 Comp. E SXM 245 0.29 0.62 0.45 0.46 0.73 0.75 Ex. 3 880 Ex. 3 F 15 df, SXM 248 0.23 0.88 0.79 0.79 0.90 0.90 solid 880 Comp. D SXM 457 0.28 1.21 0.83 0.81 0.69 0.67 Ex. 4 9200 Comp. D SXM 461 0.32 1.06 0.66 0.70 0.62 0.66 Ex. 5 9200 Ex. 4 G 9 df, SXM 460 0.25 1.57 1.92 2.06 1.22 1.31 hollow 9200 Ex. 5 G 9 df, SXM 475 0.30 1.49 1.78 1.79 1.20 1.20 hollow 9200 Ex. 6 G 15 df, SXM 454 0.28 1.37 1.48 1.52 1.08 1.11 hollow 9200 Ex. 7 G 15 df, SXM 451 0.34 1.23 1.20 1.13 0.98 0.92 hollow 9200 Comp. H SXM 444 0.32 1.16 0.80 0.85 0.69 0.74 Ex. 6 9200 Comp. J SXM 439 0.30 1.24 1.12 1.08 0.90 0.87 Ex. 7 9200 Ex. 8 I 15 df, SXM 463 0.30 1.46 2.26 1.93 1.55 1.32 solid 9200 Ex. 9 G 15 df, SXM 476 0.28 1.87 2.29 2.11 1.23 1.13 solid 9200 Comp. H SXM 464 0.37 1.12 0.97 1.01 0.86 0.90 Ex. 8 9200 Duocore ™ System 1 500 2.48 0.99 0.79 0.40 0.32 Huggies Ultra-trim ™, 850 2.12 1.16 1.20 0.55 0.56 Step 4 2
[0087] As indicated in Table 1, absorbent cores formed in accordance with the present invention exhibit beneficial intake characteristics, such as initial acquisition rates, in comparison to comparable absorbent cores formed without synthetic fiber.
[0088] Further, the beneficial acquisition rates of the present invention do not deteriorate as dramatically after the initial insult as compared to comparable absorbent cores produced without synthetic fiber. In fact, in advantageous embodiments, the acquisition rate improves with successive insults, i.e. the ratio of the successive insults to the initial insult is greater than 1.0, which is altogether unexpected. In the case of absorbent cores made with conventional processes, such as pocket forming and thermal bonded airlaid, it has been found that during multiple insults the intake performance of absorbent cores starts decreasing dramatically, as indicated both by the performance of the HUGGIES ULTRATRIM™ and DUOCORE™ Samples provided in Table 1. As shown in Table 11, for conventional absorbent cores, the ratio of the acquisition rate for the 2 nd insult compared to the 1 st insult (i.e. the second insult ratio) and ratio of the acquisition rate for the 3 rd insult compared to the 1 st insult (i.e. the third insult ratio) is generally less than about 0.6. Consequently, upon multiple insults the ability of the absorbent core to rapidly acquire liquid starts diminishing, which in turn leads to increased pooling and leakage. The acquisition rate trend for conventional absorbent cores following multiple insults is also graphically represented in FIG. 4. The trend plotted in FIG. 4 can be expected in absorbent cores present in leading diapers such as HUGGIES ULTRA-TRIM™ or PAMPERS BABY DRY™ as well as air-laid absorbent cores such as those offered by Buckeye Technologies (under the brand name DUOCORE SYSTEM™).
[0089] In contrast, the acquisition rates of the present absorbent cores do not diminish as rapidly. More particularly, in beneficial embodiments of the invention, the ratio of the acquisition rate for the 2 nd insult/1 st insult is greater than 0.9 and the ratio of the acquisition rate for the 3 rd insult/1 st insult is also greater than 0.9. Surprisingly, when Applicants included synthetic fibers in accordance with particularly advantageous embodiments of the present invention, the intake performance of the absorbent cores actually started improving after the first liquid insult, as indicated by several of the Examples in Table 11 and graphically illustrated in FIG. 5. More specifically, in particularly advantageous embodiments of the invention, the ratio of the acquisition rate for the 2 nd insult/1 st insult is greater than 1.0 and the ratio of the acquisition rate for the 3 rd insult/1 st insult is also greater than 1.0.
[0090] Examples 10 through 14 in accordance with present invention were produced using the layer compositions provided as Recipes K, L and M below. The specific recipe corresponding to each of Examples 10 through 14 is noted in Table 2. The samples were produced using 17 gsm tissue as the carrier layer, commercially available as designated grade 3008 from Cellu Tissue Corporation. The SAP used was SXM 9200, obtained from Stockhansen GmbH, Krefeld, Germany. The TAB nonwoven was a 40 gsm Libeltex grade T-9 carded through-air bonded nonwoven available from Libeltex in Meulebeke, Belgium. The cellulose fiber was untreated pulp fiber identified as RAYFLOC-J-LD pulp fiber, commercially available from Rayonier Inc. of Jesup, Ga.
[0091] The samples were made in accordance with the process shown in FIG. 3, except that a nonwoven sheet was introduced either between or prior to the forming heads, as indicated noted below. In addition to the nonwoven sheet, each of the absorbent core samples included airlaid material deposited by one or more forming heads, as noted within Recipes K, L and M. The configurations for the various recipes are described below:
% in Each Forming Head Nonwoven % of total SAP Type Pulp basis weight RECIPE K Tissue 3% Nonwoven TAB 8% FH 1 63% 37% 16% FH 2 63% 37% 16% FH 3 63% 37% 16% FH 4 63% 37% 16% FH 5 63% 37% 17% FH 6 100% 8% RECIPE L Tissue 3% FH 1 63% 37% 16% FH 2 63% 37% 16% FH 3 63% 37% 16% Nonwoven TAB 8% FH 4 63% 37% 16% FH 5 63% 37% 17% FH 6 100% 8% RECIPE M Tissue 3% FH 1 63% 37% 16% FH 2 63% 37% 16% FH 3 63% 37% 16% FH 4 63% 37% 16% FH 5 63% 37% 17% Nonwoven TAB 8% FH 6 100% 8%
[0092] Table 2 provides the composition of and properties exhibited by Examples 10 through 14. The basis weight and density of each sample were again determined using methods well known in the art. The acquisition, or intake, rates were determined using the standard intake rate test described above.
TABLE 2 Insult Insult Basis Intake Rate, mL/s 2/1 3/1 Sample Recipe Weight Density Insult Insult Insult Rate Rate ID ID gsm g/cc 1 2 3 Ratio Ratio Ex. 10 K 469 .36 1.26 1.24 1.03 .98 .82 Ex. 11 L 470 .29 1.52 1.73 1.30 1.14 .86 Ex. 12 M 466 .29 1.28 1.11 .96 .87 .75 Ex. 13 K 480 .34 1.27 1.26 1.11 1.00 .87 Ex. 14 L 467 .27 1.63 2.10 1.67 1.29 1.02
[0093] As shown in Table 2, aspects of the invention incorporating pre-formed nonwoven sheet exhibited acquisition rate properties comparable to Examples 1 through 9. More particularly, all of the second and a majority of the third intake rates are at least 80% as fast as the first intake rate, as shown in Table 15. Surprisingly, samples in which the synthetic fiber was placed only in an intermediate layer provided beneficial acquisition rate properties as well.
[0094] Examples 15 through 17 in accordance with present invention were produced using the layer compositions provided as Recipes Q, R and U below. The specific recipe corresponding to each of Examples 15 through 17 is noted in Table 3. Comparative Example 9 was produced using the layer composition provided as Recipe W below. The samples were produced using 17 gsm tissue as the carrier layer, commercially available as designated grade 3008 from Cellu Tissue Corporation. This carrier tissue was placed on both the top and bottom of the web. The SAP used was ASAP 2260, obtained from BASF in Portsmouth, Va. The TAB nonwoven was a 40 gsm Libeltex grade T-9 carded through-air bonded nonwoven available from Libeltex in Meulebeke, Belgium. Pulp A was untreated cellulose pulp fiber, commercially available as RAYFLOC-J-LD pulp fiber from Rayonier Inc. of Jesup, Ga. Pulp B was cold caustic treated cellulosic fiber commercially available as POROSANIER-BAT from Rayonier Inc. of Jesup, Ga.
RECIPE Q % in Each Forming Head % of total Nonwoven basis SAP Type Pulp A Pulp B weight Tissue 7% FH 1 61% 39% 13% FH 2 61% 22% 17% 13% FH 3 61% 39% 13% FH 4 61% 22% 17% 13% FH 5 61% 39% 13% Nonwoven TAB 16% FH 6 0% 100% 5% Tissue 7% RECIPE R % in Each Forming Head % of total Nonwoven basis SAP Type Pulp A Pulp B weight Tissue 7% FH 1 61% 39% 13% FH 2 61% 22% 17% 13% FH 3 61% 39% 13% Nonwoven TAB 16% FH 4 61% 22% 17% 13% FH 5 61% 39% 13% FH 6 0% 100% 5% Tissue 7% RECIPE U % of total % in Each Forming Head basis SAP Nonwoven Pulp A Pulp B weight Tissue 7% FH 1 56% 44% 14% FH 2 56% 24% 20% 14% FH 3 56% 44% 14% FH 4 56% 24% 20% 14% FH 5 56% 44% 14% Nonwoven TAB 16% FH 6 100% 7% RECIPE W % of total % in Each Forming Head basis SAP PET Pulp A Pulp B weight Tissue 7% FH 1 51% 49% 16% FH 2 51% 27% 22% 15% FH 3 51% 49% 16% FH 4 51% 27% 22% 15% FH 5 51% 49% 16% FH 6 100% 8% Tissue 7%
[0095] The composition and properties exhibited by Examples 15 through 17 are provided in Table 3. The acquisition rates for each of the samples were determined generally using the method described above. However, since Examples 15 through 17 and Comparative Example 9 have a relatively low basis weight, the acquisition rate test procedure was modified to use 55 g insults rather than the standard 100 g insults of the previous examples. The basis weights and densities were determined for the samples by methods well known in the art.
TABLE 3 Basis Insult 2/1 Insult 3/1 Sample Recipe Weight Density 55 ml Intake Rate, mL/s Rate Rate ID ID gsm g/cc Insult 1 Insult 2 Insult 3 Ratio Ratio Comp. W 243 .27 .72 .45 .38 .63 .53 Ex. 9 Ex. 15 Q 248 .20 .90 .89 .78 .98 .86 Ex. 16 R 244 .18 1.19 1.33 1.22 1.11 1.02 Ex. 17 U 278 .22 1.22 1.28 1.15 1.05 .94
[0096] As shown in Table 3, all of the second intake rates and a majority of the third intake rates are at least 80% as fast as the intake rate on the first insult for Examples 15 through, 17. Further, the majority of Examples 15 through 17 exhibit overall improved acquisition rates (i.e. first and subsequent acquisition rates) over the control sample, Comparative Example 9. Again, surprising beneficial acquisition rate properties are provided by samples having synthetic fiber in the intermediate layers alone.
[0097] Examples 18 and 19 in accordance with present invention were produced using the layer compositions provided as Recipes T and V below. The specific recipe corresponding to a given example is noted in Table 4. The sample was produced using 17 gsm tissue as the carrier layer, commercially available as designated grade 3008 from Cellu Tissue Corporation. The SAP used in Examples 18 and 19 was ASAP 2260, obtained from BASF in Portsmouth, Va. The samples contained untreated cellulose pulp fiber, Pulp A, commercially available as RAYFLOC-J-LD pulp fiber from Rayonier Inc. of Jesup, Ga. The samples further contained cold caustic treated cellulosic fiber, Pulp B, commercially available as POROSANIER-BAT fiber from Rayonier Inc. of Jesup, Ga. The PET fibers were 15-denier type 224 in a 0.25 in. length from KOSA of Charlotte, N.C.
% of total % in Each Forming Head basis SAP PET Pulp A Pulp B weight RECIPE T Tissue 7% FH 1 61% 39% 13% FH 2 61% 22% 17% 13% FH 3 61% 39% 13% FH 4 61% 22% 17% 13% FH 5 38% 38% 24% 21% FH 6 61% 39% 13% Tissue 7% RECIPE V Tissue 7% FH 1 60% 40% 13% FH 2 60% 19% 21% 13% FH 3 60% 40% 13% FH 4 60% 19% 21% 13% FH 5 33% 33% 33% 24% FH 6 0% 50% 50% 17%
[0098] The acquisition rates for Examples 18 and 19 were also measured according to the method described above, again using 55 ml insults due to the lighter material basis weight. The results for Examples 18 and 19 are provided in Table 4.
TABLE 4 Basis Insult 2/1 Insult 3/1 Sample Recipe PET Weight Density 55 ml Intake Rate, mL/s Rate Rate ID ID Type Gsm g/cc Insult 1 Insult 2 Insult 3 Ratio Ratio Ex. 18 T 15 df 249 .25 .70 .58 .55 .83 .80 Solid Ex. 19 V 15 df 252 .29 .82 .73 .68 .89 .83 Solid
[0099] Similar to the results from the previous examples, the second or third intake ratios for Examples 18 and 19 are at least 0.80. Again, Examples 18 and 19 indicate improved intake performance over Comparative Example 9 and highlight the beneficial aspects of the invention in which synthetic fiber is included within layers other than the innermost layer.
[0100] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. For example, the term “or” is not used to indicate the associated elements or terms are mutually exclusive alternatives, rather the term “or” is used in a broader sense to mean that either or both elements or terms may be present. | Multilayered absorbent cores are provided that include synthetic fiber to improve the liquid transport properties of the resulting absorbent articles. The synthetic fiber, which may be found in either the innermost and/or intermediate layers of the absorbent core, particularly improve the rewet performance of the absorbent article. The absorbent cores may be incorporated into a number of absorbent articles, including diapers, feminine hygiene products and incontinence pads. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to solid state imaging devices, and more particularly to a solid state imaging device having an optical detector section of non-crystalline silicon.
A conventional solid state imaging device comprises an optical detector section having photo-diodes arranged in a matrix form, and a scanning circuit for successively selecting signals detected by the optical detector section. One example of a conventional solid state imaging device, comprising an optical detector section matrix in combination with a field-effect transistor circuit for X-Y scanning (hereinafter referred to as "an X-Y matrix type solid state imaging device", when applicable), is disclosed in the specification of Japanese Patent Publication No. 30768/1970. Other examples, comprising an optical detector section matrix in combination with a bucket brigade device (BBD), a charge coupled device (CCD) or a CPT type charge transfer section are disclosed in the specifications of Japanese Patent Application (OPI) Nos. 1221/1971 and 26091/1972 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application") and in Electronic Materials (Denshizairyo), March 1980, page 6 et seq. In these conventional devices, the optical detector section and a circuit for successively selecting signals detected by the optical detector section (including the X-Y matrix circuit, the charge transfer circuit and a switching element, namely, a field-effect transistor for delivering charges to these circuits) are arranged two-dimensionally on a single surface. Consequently, a disadvantage of the conventional devices is that its light utility efficiency per unitary area is extremely low, i.e., only a relatively small part of the semiconductor surface area is used for detecting light.
Recently, a solid state imaging device for a multilayer structure has been proposed which is obtained by superimposing a photoconductive element on the scanning circuit. A solid state imaging device comprising a photoconductive element is superimposed on an X-Y matrix type scanning circuit using field-effect transistors (FET's) is disclosed in the specification of Japanese Patent Application (OPI) No. 91116/1974. A solid state imaging device comprising a vacuum-evaporated polycrystalline film using the hetero-junction of compound semiconductors in Groups II-VI formed on a BBD or CCD type scanning circuit is disclosed in the specification of Japanese Patent Application (OPI) No. 2777/1980. These devices have the advantage of enlarging the light detecting area of the imaging device.
Attempts have been made to use non-crystalline silicon for solar cells or electrophotographic sensitized materials. The term "non-crystalline silicon" as used herein is intended to refer to silicon not all of which have a periodic atomic arrangement and which is different from that which has a regular atomic arrangement. Accordingly, conventional non-crystalline silicon has poor photoelectric characteristics because of its lack of regularity in the arrangement of atoms. However, it has been found that a non-crystalline silicon containing hydrogen and/or fluorine has a large photoconductivity characteristic with a relatively high resistivity (10 8 to 10 9 Ω-cm). Hydrogen and fluroine decrease the gap state of electrons and holes in the energy gap of non-crystalline silicon. A more important finding is that valence electron control can be effected for non-crystalline silicon similarly as in the case for crystalline silicon (as disclosed in Solid State Communication by W. E. Spear and P. G. LeComber, Vol. 17 (1975), page 1193 et seq.). A significant amount of attention has been paid to the characteristics and applications for non-crystalline silicon particularly to its application to photovoltaic devices as described in Applied Physics Letters by D. E. Carlson and C. R. Wronski, Vol. 28 (1976), page 671 et seq.
Japanese Patent Application (OPI) No. 39404/1980 describes the use of non-crystalline silicon as a photoconductive element in the above-described multilayer structure solid state imaging device. As described there a single layer of non-crystalline silicon is electrically connected to the source or drain electrode of a field-effect transistor in an X-Y matrix type or charge transfer type scanning circuit which is combined with MOS field-effect transistors arranged in a matrix form, and a transparent electrode is formed on the single layer of non-crystalline silicon.
SUMMARY OF THE INVENTION
In accordance with the present invention an improved solid state imaging device of the type using non-crystalline silicon (hereafter sometimes referred to as a-Si) as the light detecting medium is provided. As contrasted with the prior proposals for using a-Si, in the present invention plural layers of a-Si are provided. Specifically, a plurality of repetitive layers are superimposed on one another, each repetitive layer consisting of a p-type semiconductor sublayer, an intrinsic semiconductor sublayer, and an n-type semiconductor sublayer. The combination of repetitive layers is laminated on the semiconductor scanning circuit. In contrast with the devices using a single a-Si layer, the present invention does not require biasing of the a-Si layers.
The non-crystalline material essentially containing silicon employed in the present invention is not limited to a non-crystalline silicon containing hydrogen or the like. A part of a non-crystalline silicon containing hydrogen or the like can be replaced by carbon or the like which is an element in the same group as silicon, or an impurity element such as oxygen or nitrogen can be contained in the silicon. Hereinafter, these materials will be referred to as "non-crystalline silicon".
An object of this invention is to provide a solid state imaging device in which non-crystalline silicon is employed as the optical detector.
Another object of the invention is to provide a solid state imaging device which is operated without application of a bias voltage or which is operated with application of an extremely low bias voltage.
The foregoing objects and other objects of the invention have been achieved by the provision of a solid state imaging device in which a transparent electrode and a photoconductive layer are arranged in the direction of incidence of light in the stated order, and a plurality of scanning circuits are provided to successively select a signal of the photoconductive layer; in which, according to the invention, the photoconductive layer is made of a valence electron controllable non-crystalline material essentially containing silicon by laminating a plurality of repetitive units each consisting of a p-type semiconductor layer, an intrinsic semiconductor layer and an n-type semiconductor layer, in such a manner that adjacent semiconductor layers are different in electrical conductivity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of one unit of a solid state imaging device according to this invention.
FIG. 2 is an explanatory diagram showing the sectional structure of an optical detector section of the device shown in FIG. 1.
FIG. 3 is a plan view showing a plurality of units shown in FIG. 1, which are arranged one-dimensionally.
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of this invention will be described with reference to the accompanying drawings.
FIG. 1 is a sectional view showing the structure of one unit or pixel of a solid state imaging device. It is well known in the art that a solid state imaging device consists of a matrix of pixels, each pixel corresponding essentially to a spot in a picture. Details of such solid state imaging devices which are not novel features of the present invention will not be described herein as such features are well known in the art, and their inclusion here would unnecessarily encumber the description of the novel features of the invention. In the embodiment, a diode is formed with an n + type region 11 in a p-type semiconductor substrate 10. A p + type region 12 is a potential barrier for preventing the injection of electrons from the n + type region 11 in a CCD operation. An n + type region 13 is a potential well in a BBD operation. The regions 12 and 13 are provided only in the CCD operation and the BBD operation, respctively.
The emboidment will be described with reference to the BBD operation. In FIG. 1, reference numeral 14 designates a first gate electrode which partially overlaps the n + type region 11; 16, a gate oxide film serving as an insulating film between the semiconductor substrate 10 and the first gate electrode 14; 15, an insulating layer which electrically isolates a first electrode 17 from the semiconductor substrate 10 and the first gate electrode 14; 17, the aforementioned first electrode which is connected to the n + type region 11; 18, a photoconductive layer of non-crystalline silicon; and 19, a transparent electrode formed on the non-crystalline silicon layer. The photoconductive layer 18 is obtained by laminating repetitive units each consisting of a p-type semiconductor layer, an intrinsic semiconductive layer and an n-type semiconductor layer (hereinafter referred to merely as "a p-layer", "an i-layer" and "an n-layer", or "p", "i" and "n", respectively, when applicable) in such a manner that adjacent semiconductor layers are different in electrical conductivity (or the p-type semiconductor layer of one repetitive unit and the n-type semiconductor layer of another repetitive unit are adjacent to each other). The layer 18 forms a photo-detector section.
The order of lamination of the layers (i.e., the p, i and n layers) of the repetitive units of the photoconductive layer 18 is as shown in FIG. 2 in the case where a scanning circuit is of a p channel FET. More specifically, the layers should be laminated in the order of p, i and n in the direction of application of light. When the scanning circuit is of an n channel FET, the layer should be laminated in the order of n, i and p in the direction of application of light.
When light 20 is applied to the photo-detector section of the solid state imaging device thus constructed, the p-i-n photo diodes of non-crystalline silicon laminated in the form of plural layers absorb the light to form pairs of electrons and holes, which are brought to the electrodes 17 and 19 by the optical electromotive force, to decrease the potential of the electrode 17. The amount of decrease of the potential is proportional to the amount of incident light and is accumulated for one field period of the scanning system.
Next, when a read signal voltage is applied to the first gate electrode 14, the surface potential of the semiconductor below the first gate electrode 14 is increased, as a result of which electrons are transferred into the n + region 13 from the n + region 11, and accordingly the potential of the n + region 11 is restored. Thus, the total amount of charge moved to the n + region 13 is proportional to the intensity of illumination of the incident light.
The photo-detection and charge transfer operations of a single pixel or unit of the solid state imaging device has been described. The further charge transfer of a photoelectric conversion signal in n + type region 13 is carried out in a conventional manner. For example, the charge transfer can be achieved by self-scanning described below.
FIG. 3 is a plan view showing units of solid state elements shown in FIG. 1 which are arranged one-dimensionally. In FIG. 3, reference numeral 21 designates one pixel or unit of the solid state imaging device. The plan or dimensions of the charge storage and switching portion of the pixel are represented by a broken line. Second gate electrodes 22 and 24 are provided between the first electrodes 14 and 23 of adjacent units. Charges transferred to region 13 by the first electrode 14 is as described above, are further transferred, in a charge transfer mode, to a region of the semiconductor below the second gate electrode 22 by application of a transfer pulse in a manner well known. The charges thus transferred are transferred to an output stage successively through the first gate electrode 23 and the second gate electrode 24 according to the same principle as that described above. That is, the signal subjected to photoelectric conversion in the photo-detector section can be delivered to the output stage by a two-phase clock pulse signal.
The switching scanning circuit described above is of the charge transfer type, e.g., CCD or BBD circuits. However, an X-Y matrix type scanning circuit as disclosed, for instance, in the specification of Japanese Patent Application (OPI) No. 91116/1974 may be employed. In addition, instead of the above-described field-effect transistor circuit, a film type field-effect transistor circuit formed on a glass support, as disclosed in Proceeding of the IEEE, the Institute of Electrical and Electronics Engineers, Inc., Dec. 1964, Vol. 52, No. 12, pp. 1479-1486 may be used. Furthermore, the scanning circuit can be formed with conventional semiconductor switching circuits.
The operation of the photo-detector section employed in the invention, and a method of manufacturing the photo-detector section will be described.
The specific feature of the solid state imaging device according to the invention resides in that a valence electron controllable non-crystalline silicon is formed by laminating a plurality of repetitive units each consisting of p, i and n on the above-described scanning circuit in such a manner that the layers of adjacent repetitive units are different in electrical conductivity.
When such a p-i-n multilayer structure is used, a field-effect due to the optical electromotive force of the solid state imaging device can be obtained without the bias voltage of the device. A principle for this will be described. In general, a p-n junction, unlike a p-i-n junction, shows a very low rectification characteristic. In an element having p-i-n and p-n junctions the rectification characteristic depends on the p-i-n junctions of the repetitive units, and the p-n junctions between the repetitive units scarcely contribute to the rectification characteristic. That is, if a simple structure of p-i-n/p-i-n . . . /p-i-n (hereinafter expressed as "(p-i-n) m ", when applicable) is formed, the n/p junctions between the p-i-n units serve merely as a low resistance junction, and a multilayer structure optical electromotive force element is formed. In other words, in the n/p junction connecting the p-i-n units, electrons and holes produced in a tunnel recombination mode are recombined, and therefore one current path is formed in the element.
In practice, such a p-i-n multilayer structure can be readily manufactured by a glow discharge method. The structure can be formed by successively and repeatedly forming the n-layer with a gas SiH 4 +PH 3 , the i layer with a gas SiH 4 and the p-layer with a gas SiH 4 +B 2 H 6 for instance on a stainless steel plate or a substrate covered with a conductive film. As the speed of deposition is relatively low, the thickness of each layer can be relatively readily controlled. This method is utilized in the invention, to form the p-i-n multilayer structure non-crystalline silicon on the electrode 17 in FIG. 1. The non-crystalline silicon can be formed by the conventional glow discharge method or by a sputtering method which is carried out in an atmosphere including hydrogen and/or fluorine gas. By way of example, a method of manufacturing the non-crystalline silicon according to the glow discharge method will be described.
In a manufacturing method according to glow discharge decomposition, a compound containing silicon is decomposed by glow discharge to allow non-crystalline silicon to deposit on the substrate. Examples of the compound are SiH 4 , SiF 4 , SiHF 3 , SiH 3 Cl and SiH 2 Cl 2 which are represented by a general formula SiHxX 4-x (where X is F, Cl or I, and x=0 to 4 (an integer)), or mixtures of these compounds. In order to form a high resistance film having a combination of Si--C, Si--O or Si--N, a gas CH 4 , O 2 , NO 2 or NH 3 may be mixed with the above-described gas. These compounds are normally gaseous, and they are used as they are or they are used after being diluted with inert gas such as Ar, He or Xe or gas such as H 2 . When a silicon compound containing no hydrogen or fluorine is used, it is essential to use hydrogen or fluorine in combination therewith. The gas in a container for glow discharge is, in general, manitained at 10 -2 to 10 Torr. A direct current, or an alternating current, or a current obtained by superposing the direct current and alternating current may be applied between the electrode and the substrate. In the use of the alternating current, a frequency from 1 Hz to 4,000 MHz may be employed. In forming the above-described non-crystalline silicon film, the amount of doping hydrogen is 10 to 40 atomic percent. The non-crystalline silicon film can also be formed by other methods, such as sputtering and ion plating.
The electrical conductivity type of the non-crystalline silicon thus manufactured is slightly n-type; however, its valence electron control can be made by doping. That is, p-type properties can be given to the non-crystalline silicon by doping it with a small amount of boron. Thus, an intrinsic semiconductor (i-type semiconductor) can be formed, and a p-type semiconductor can be formed. Furthermore, an n-type semiconductor can be formed by adding, for instance, phosphorus. Suitable examples of the doping impurities are elements in Group III of the Periodic Table, such as B, Al, Ga, In and Tl in the formation of the p-type semiconductor, and are elements in Group V of the Periodic Table, such as N, P, As, Sb and Bi in the formation of the n-type semiconductor. As the contents of these impurities are extremely small, the risk of public hazard due to their use in not serious. However, it is desirable to use impurities which are the least harmful. In view of this requirement, and the electrical and optical characteristics of a photoconductive layer, boron and phosphorus are most suitable dopants.
The quantity of impurities doped into the non-crystalline semiconductor according to the invention is suitably determined according to desired electrical and optical characteristics; however, it is desirable that in the case of elements in Group III of the Periodic Table it is 10 -6 to 5 atomic percent, preferably 10 -5 to 1 atomic percent, and in the case of elements in Group V of the Periodic Table it is 10 -6 to 1 atomic percent, preferably 10 -4 to 10 -1 atomic percent.
The exact quantity of doping impurities are not critical and will depend on the temperature of the substrate.
By the above-described doping technique, the p-i-n multilayer type non-crystalline silicon is formed as the optical detector section of the invention.
Concrete examples of the thicknesses of the layers which are required for obtaining an electric field necessary for the optical detector section of the solid state imaging device are as follows: The thickness of the p-layer is preferably of the order of 50 to 100 Å with the ratio of B 2 H 6 /SiH 4 being 0.1% and being doped with boron. The thickness of the n-layer is preferably of the order of 100 to 500 Å with the ratio of PH 3 /SiH 4 being 0.2% and being doped with phosphorus. These thicknesses can be obtained by glow discharge with the substrate at 200° to 300° C. In the case where the thickness of the p-layer of the first unit from the light incidence side is about 100 Å, the thickness of the n-layer of the last (or the m-th) unit is about 500 Å, and the thicknesses of the p-layers and the n-layers between the aforementioned p- and n-layers are about 50 Å and about 100 Å, respectively, the best data for the thickness di of each i-layer are as indicated in the following Table 1:
TABLE 1______________________________________dim di.sub.1 di.sub.2 di.sub.3 di.sub.4 di.sub.5______________________________________2 500 5,0003 350 900 5,0004 150 450 1,400 5,0005 110 300 700 1,700 5,000 (Unit: Å)______________________________________
However, this data for the thickness of the i-layer should not be considered as limits on their thickness. That is, as a result of experiments, the inventors have found that an electric field of 4.5 V, sufficient as the bias voltage of the optical detector section of the solid state imaging device, can be obtained by application of sunlight to a photoconductor constructed as described above and having ten layers of p-i-n, with each i-layer having a thickness of 500 Å.
As the number (m) of layers of the p-i-n repetitive units according to the invention is increased, the conversion percentage is slightly decreased. However, the conversion percentage is about 3.6 to 4.1% in the case of an a-Si photoconductor having five repetitive p-i-n layers and the voltage is increased in proportion to the number (m) of layers. However, even with two p-i-n layers a voltage of 1 V or higher is induced in the optical detector section of the solid state imaging device, and with three p-i-n layers or more the voltage induced is of the order of 2 V and up. Thus, it is necessary to provide at least two repetitive p-i-n layers as the photoconductor layer.
The invention has been described with reference to the case where the electrons and holes paired in the photoconductive layer migrate to the source or drain region of the field-effect transistor under the influence only of the optical electromotive force of the non-crystalline silicon made up of the repetitive p-i-n layers, without using the bias voltage; however, the invention is not limited thereto or thereby; that is, a bias voltage may be applied to supplement the optical electromotive force.
The same non-crystalline silicon film as that described above can be obtained by subjecting silicon to high frequency or DC sputtering in an atmosphere containing a hydrogen gas or SiH 4 gas. The transparent electrode 19 is obtained by forming a transparent electrode containing In 2 O 3 or SnO 2 into one having a thickness of 0.05 to 0.5 μ. | A solid state imaging device using a non-crystalline semiconductor material as a photoconductive member. The photoconductive member is arranged in repetitive p-i-n layers such that an opto electromotive force is developed sufficient to drive charges to an integrated scanning circuit even in the absence of an external bias voltage. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of Provisional Patent Application No. 61/953,483, filed on Mar. 14, 2014, and is incorporated herein by reference in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present disclosure is generally directed toward electronic communications and more specifically for electronic communications utilized for conferencing parties.
BACKGROUND
[0003] Video and audio quality in a conference ultimately impacts the user's overall experience and, therefore, whether the conference was successful. The real-time nature of audio and video traffic in a live conference make their management important. Video requires more data and, therefore, is more likely to be impacted by poor quality, especially when bandwidth becomes constrained.
[0004] While users may tolerate portions of a video with poor quality, such as video comprising a single person speaking (e.g., a broadcast), other videos require high quality for successfully interactive participation. For example, a video of a surgical procedure may be incomprehensible if fine detail is omitted or if the frame rate drops to the point that subtle actions are omitted. It is also common for a conference to include images of a live presentation, which may include a screen receiving projected images. If those images include graphs, reports, documents, or other finely detailed information, the content may be of little value if the video quality is not sufficient to convey the images in a usable form.
[0005] Conference quality can be affected by a number of factors. One of the most important factors is the connection speed of each participant's system and codecs used by each participant. When packets of video conference data drop, the quality of the conference decreases, and the process of resending the packets is not always error-free. However, other areas of creating, transmitting, and receiving teleconferencing can be subject to failure, overloading, misconfiguration, or other issue that resulting in a poor quality conference for one or more participants.
SUMMARY
[0006] It is with respect to the above issues and other problems that the embodiments presented herein were contemplated.
[0007] In one embodiment, a user's device is provided with an input, from the user, during a video, audio, or multimedia conference. The user's input triggers a quality signal that, among other things, may provide an indication to the other participants of the conference that the user is experiencing quality issues. In one embodiment, a button or user input may be presented to a user on their endpoint device that allows the participant to indicate that the quality of the received audio, video, or both is sub-optimal, unintelligible, or otherwise negatively impacting the participant's overall conference experience. The threshold of quality that results in the user's input is user determined and may be based, in whole or in part, on the content of the presentation, the participant's tolerance, the specific channel in which this problem exists, and so on. For example, a poor video signal may be acceptable to a user if the video is of a speaker talking and if the audio signal remains of acceptable quality. As another example, a conference where the participants are engaged in a discussion and, much like many in-person conferences, interrupt or talk over other participants, may be determined by a user to be of poor quality if the audio signal is delayed, even slightly, if the delay puts the participant at a disadvantage during more lively and interactive portions of the conference.
[0008] The quality feedback of the present disclosure may be provided as an indicator to other participants in the conference, a system administrator, and/or the conference bridge/server itself. With the knowledge that one or more participants are having quality issues, actions can be taken to correct and/or mitigate the issues. For example, a conference server may perform one or more of the following:
Begin recording media at the source, media server, and/or recipient, such as for troubleshooting and/or later playback; Multiple recipient recordings, such as for fault isolation; Assess where the problem might exist (e.g., if all or any participants indicate quality issues, the problem may be with the media server or source); Begin or continue annotation of the conference transcript; and Begin or continue with real time transcription via speech-to-text, which may be delivered on the same or alternate data channel to only those participants having issues, all participants, self-selected participants, or other subset of participants.
[0014] The foregoing may be fully automated remedial measures performed by the conference server to initiate a quality management action without requiring any human input or, alternatively, suggesting an action for confirmation and approval by a human user (e.g., system administrator, conference host, conference participant(s), etc.).
[0015] The quality feedback, when provided to other participants, enables those other participants to understand the extent of quality problems for the conference as a whole. Instead of prior art systems that just provided quality feedback to the specific user reporting quality issues, the present invention provides a simple and effective user interface (UI) that can inform all participants as to whether or not other participants have reported quality issues and, if so, the extent of those quality issues.
[0016] In one embodiment, a conferencing system is disclosed, comprising: a network interface configured to receive a quality signal from a first endpoint involved in a conference, the quality signal being sent by the first endpoint in response to a user input received at the first endpoint during or immediately after the conference; a conference server configured to receive the quality signal from the first endpoint via the network interface and; upon receiving the quality signal, causing each of a number of secondary endpoints involved in the conference to present indicia of the quality signal, and at least one of the secondary endpoints to execute a quality management action that causes (i) the conference to be recorded, (ii) launching a service level agreement monitor application, and (iii) rerouting at least a portion of the conference.
[0017] In another embodiment, a server is disclosed, comprising: a network interface configured to receive a quality signal from a first endpoint involved in a conference, the quality signal being sent by the first endpoint in response to a user input received at the first endpoint during or immediately after the conference; a processor configured to, upon receiving the quality signal, causing each of a number of secondary endpoints involved in the conference to present indicia of the quality signal and execute a quality management action that includes at least one of: (i) recording the conference, (ii) launch a service level agreement monitor application, and (iii) reroute at least a portion of the conference.
[0018] In yet another embodiment a method of managing a conference for a number of endpoints, comprising: receiving, at a conferencing server, a quality signal from a first endpoint of the number of endpoints involved in a conference, the quality signal being sent by the first endpoint in response to a user input received at the first endpoint during or immediately after the conference; and upon receiving the quality signal causing the number of endpoints to present indicia of the quality signal and executing, by the teleconferencing server, a quality management action that includes at least one of: (i) recording the conference, (ii) launching a service level agreement monitor application, and (iii) rerouting at least a portion of the conference.
[0019] The phrases “at least one,” “one or more,” and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.
[0020] The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising,” “including,” and “having” can be used interchangeably.
[0021] The term “automatic” and variations thereof, as used herein, refers to any process or operation done without material human input when the process or operation is performed. However, a process or operation can be automatic, even though performance of the process or operation uses material or immaterial human input, if the input is received before performance of the process or operation. Human input is deemed to be material if such input influences how the process or operation will be performed. Human input that consents to the performance of the process or operation is not deemed to be “material.”
[0022] The term “computer-readable medium” as used herein refers to any tangible storage that participates in providing instructions to a processor for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, NVRAM, or magnetic or optical disks. Volatile media includes dynamic memory, such as main memory. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, magneto-optical medium, a CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, a solid state medium like a memory card, any other memory chip or cartridge, or any other medium from which a computer can read. When the computer-readable media is configured as a database, it is to be understood that the database may be any type of database, such as relational, hierarchical, object-oriented, and/or the like. Accordingly, the disclosure is considered to include a tangible storage medium and prior art-recognized equivalents and successor media, in which the software implementations of the present disclosure are stored.
[0023] The terms “determine,” “calculate,” and “compute,” and variations thereof, as used herein, are used interchangeably and include any type of methodology, process, mathematical operation or technique.
[0024] The term “module” as used herein refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and software that is capable of performing the functionality associated with that element. Also, while the disclosure is described in terms of exemplary embodiments, it should be appreciated that other aspects of the disclosure can be separately claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The present disclosure is described in conjunction with the appended figures:
[0026] FIG. 1 depicts a conference system in accordance with embodiments of the present disclosure;
[0027] FIG. 2 depicts a packet reception graph in accordance with embodiments of the present disclosure;
[0028] FIG. 3 depicts an endpoint display in accordance with embodiments of the present disclosure;
[0029] FIG. 4 depicts a first quality management timeline in accordance with embodiments of the present disclosure; and
[0030] FIG. 5 depicts a second quality management timeline in accordance with embodiments of the present disclosure.
DETAILED DESCRIPTION
[0031] The ensuing description provides embodiments only, and is not intended to limit the scope, applicability, or configuration of the claims. Rather, the ensuing description will provide those skilled in the art with an enabling description for implementing the embodiments. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the appended claims.
[0032] Any reference in the description comprising an element number, without a subelement identifier when a subelement identifiers exist in the figures, when used in the plural is intended to reference any two or more elements with a like element number. When such a reference is made in the singular form, it is intended to reference one of the elements with the like element number without limitation to a specific one of the elements. Any explicit usage herein to the contrary or providing further qualification or identification shall take precedence.
[0033] The exemplary systems and methods of this disclosure will also be described in relation to analysis software, modules, and associated analysis hardware. However, to avoid unnecessarily obscuring the present disclosure, the following description omits well-known structures, components and devices that may be shown in block diagram form, and are well known, or are otherwise summarized.
[0034] For purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the present disclosure. It should be appreciated, however, that the present disclosure may be practiced in a variety of ways beyond the specific details set forth herein.
[0035] FIG. 1 depicts conference system 100 in accordance with embodiments of the present disclosure. In one embodiment, users 108 use endpoints 106 to connect to network 102 over their associated connections 110 . Endpoints 106 are electronic devices operable to present at least a portion of a conference to at least one user 108 . Endpoints 106 may also provide teleconferencing input from users 108 such that at least one endpoint 106 may provide video, audio, files, etc. for inclusion in the conference. In another embodiment, endpoints 106 comprise a display (video, audio, and/or tactile) operable to present indicia of a quality signal associated with another user 108 and their respective endpoint 108 . Endpoints 106 include, but are not limited to, a telephone, smart phone/cellular phone, computer (desktop, notebook, tablet, etc.), and composite devices (e.g., headset and base station).
[0036] Connection 110 may be determined, in whole or in part, by the type of device embodied by a particular endpoint 108 . For example, when endpoint 106 A is embodied as a cellular phone, connection 110 A may comprise a cellular connectivity and network 102 may then further comprise a cellular network. As can be appreciated, the user of one particular communication 110 (e.g., WiFi, infrared, Bluetooth, cellular, Ethernet, etc.) may further incorporate other or alternative types of network 102 (e.g., Internet, WAN, LAN, etc.). In other embodiments, the use of a particular communication 110 and, at least a particular portion of network 102 , may be a matter of implementation choice. For example, endpoint 106 A may be a smart phone capable of receiving a conference over a cellular communication network portion of network 102 , however, endpoint 106 A may be configured to utilize WiFi connectivity 110 A to access network 102 and thereby omit cellular portions while endpoint 106 A is configured to access the conference via WiFi portion of network 102 .
[0037] Network 102 , as introduced above, is variously embodied. Embodiments, of network 102 include, but are not limited to Internet, VPN, WAN, LAN, cellular, and wired and/or wireless networks operable to convey electronic communication data between endpoints 106 and/or server 104 . In one embodiment, server 104 provides connectivity and/or content with respect to a conference. For example, server 104 may provide administration functions (e.g., invite, add, remove, floor control, etc.), content creation (e.g., camera control, audio control, insertion of previously created content such as presentation decks, videos, etc.), and/or content presentation (e.g., encoding/compression, streaming, etc.). Server 104 may be embodied as a dedicated or shared device having at least one microprocessor and include, without limitation, a stand-alone server, multiple servers, and shared computing platform. For example, server 104 and a particular endpoint 106 may both operate on the same computing device.
[0038] In another embodiment, connection 110 D (illustrated as a dashed line) is at least partially compromised such that the conference presented on endpoint 106 D is problematic as determined by user 108 D. One or more users 108 A- 108 C may infer a meaning, typically negative, to the lack of engagement from user 108 D (e.g., user D is uninterested, user D is asleep, etc.). However, if users 108 A- 108 C are made aware that user 108 D is having quality issues associated with the conference any lack of response or delayed response by user 108 D will be better understood by users 108 A- 108 C as a conference limitation. Communication errors in the presentation of the conference may also be mitigated. For example, user 108 A may assume users 108 B, 108 C heard and/or saw a particular portion of the conference (e.g., “We need to move next week's meeting up an hour.”) but, seeing indicia associated with user 108 D indicating quality issues, seek confirmation from user 108 D that the portion was received (e.g., “User D, did you catch that?”).
[0039] FIG. 2 depicts packet reception graph 200 in accordance with embodiments of the present disclosure. In one embodiment, graph 200 represents the packet reception of user 108 D. Graph 200 may represent other quality indicators and/or combination of quality indicators in addition to packets received, such as timeliness, packets received versus packets dropped, etc.
[0040] Graph 200 comprises a user determined acceptable quality line 204 . If the packets received fall below this line, whether or not the user is aware of the number of packets received, the user finds the conference problematic. The line 204 is illustrated as straight for the portion illustrated by graph 200 , however, line 204 may vary, such as by comprising a number of stair-steps. For example, a conference presentation requiring fine visual detail (e.g., documents projected on a screen and captured by a camera for the conference) may be associated with line 204 being higher than if the conference does not require a high level of visual detail (e.g., a presenter stands at a podium and speaks). Each of users 108 may have their own preference as to acceptability and their own line 204 which may be the same or different from any other user 108 .
[0041] A service level agreement (SLA) may be in place that specifies a minimum threshold, such as SLA acceptable line 206 . A SLA monitoring application may be running or launched, such as one potential quality management actions. Systems are well known to address data streams that fall below an SLA threshold and may be independently operated along with the embodiments disclosed herein. For example, if packet count line 202 falls below SLA line 206 , which would also be below user acceptable line 204 , a network administrator could be notified in accordance with an SLA. Additionally, and in accordance with certain embodiments disclosed herein, other users 108 participating in the conference could be notified that the particular user associated with packet count line 202 is having difficulties.
[0042] In another embodiment, user 108 D causes a quality signal to be sent at point 208 , as will be disclosed in more detail with respect to FIGS. 3-5 . Users 108 A- 108 C receive an indication of user 108 D and the quality issues associated with that particular user. Additionally, a first quality management action is launched which is designed to improve quality of the conference as observed at by user 108 D at endpoint 106 D. For example, server 104 may stop sending conference status updates (e.g., who is speaking, who joined, who dropped, etc.) to user 108 D in an effort to reduce packet traffic associated with non-conference content.
[0043] In another embodiment, user 106 D causes a second quality signal 210 to be sent. A second quality management action is launched, such as re-routing of some or all of the conference content.
[0044] FIG. 3 depicts an endpoint display 300 in accordance with embodiments of the present disclosure. In one embodiment, status panel 302 displays participants 306 in the conference and statuses of participants 306 . In another embodiment, quality signal panel 304 displays button 312 whereby a user 108 may report a quality issue and trigger a quality signal. In other embodiments, button 312 may be used as a confirmation and/or used affirmatively for the reporting of good quality, whereby the absence of the quality signal is understood to indicate poor quality. When a quality signal is sent, button 312 may automatically reset after a period of time and User D 108 D is then promoted to again select button 312 or asked to confirm if they are still having issues. Quality panel 304 and button 312 are provided on endpoints 106 so that users 108 may report quality issues with the conference.
[0045] Status panel 302 may be provided to endpoints 106 by default, as a matter of user choice (e.g., user determined hide, display, minimize, etc.), upon an update event (e.g., user D recently sent a quality signal), periodically, and/or other event. In one embodiment, icon 314 is associated with user 306 F to indicate a quality issue being reported by user 306 F (e.g., “User D” 108 D). Additionally, status panel 302 may be provided to non-participants (e.g., system administrators). Status panel 302 may include other indicators such as the presence of video/camera icon 308 and the presence of audio/microphone icon 310 . For example user 306 C presence indicates no camera or no operational camera icon 308 B. User 306 D is indicating no microphone or sound icon 310 C. However users 306 C, 306 D are grouped with group panel 306 B indicating commonality of location (e.g., “Conference Room A”). Therefore, observers of panel 302 may conclude that users 306 C, 306 D, between the two of them, have an operational camera/video and speaker/microphone. In other embodiments, the system may infer that two or more users, (e.g., users 306 C and 306 D) share a camera and/or microphone and conclude that their common location (e.g., Conference Room A) has audio and/or video problems. As a further embodiment, icon 314 maybe audible (e.g., tone, computer generated/playback spoken message, etc.) and/or tactile (e.g., vibration, vibration pattern, Braille, etc.)
[0046] Icon 314 may be a visual indicator, such as the illustrated exclamation mark or other indicator that may be interpreted as a quality signal by an observer of status panel 302 . For example, icon 314 may be a color, flash of text (e.g., the user's identifier (“User D”), the status (“poor quality reception”)), gradient, or other indicator associated with a quality issue perceived by user 306 F. Icon 314 may be further implemented into a channel icon. For example, user 306 F having audio problems and triggering a quality signal associated with audio, may cause icon 310 E to flash, change color, or other symbol to indicate user 306 F is having audio-specific quality issues.
[0047] FIG. 4 depicts first quality management timeline 400 in accordance with embodiments of the present disclosure. In one embodiment, at time 402 a conference starts and at some point thereafter, at time 404 , user 1 reports a quality issue. In response to user 1 reporting a quality issue at time 404 , first remedial action is launched at time 406 .
[0048] The quality management action launched at time 406 is variously embodied and includes, but is not limited to, causing endpoints 108 to present indicia of the quality signal reported at time 404 , trigger a recording of the conference by server 104 , trigger recording of conference by at least one endpoint 106 not associated with the endpoint reporting at time 404 , cause a speech-to-text application to be launched which may be recorded and/or inserted in to a video portion of the conference, and/or launch a SLA monitoring application. Once recorded, the problematic endpoint 108 may retrieve the recorded conference utilizing a lossless or less-loss protocol or retrieve the recorded conference at a time in which the quality issue is no longer a factor.
[0049] In another embodiment, user 2 reports a quality issue at time 408 and at some point thereafter, second quality management action is launched at time 410 . The second quality management action may be the same as that launched at time 406 , an extension of the first quality management action launched at time 406 , and/or the same but specific to the user 2. For example, causing endpoints 108 to present indicia of the quality signal reported at time 404 and then include indicia of the quality signal reported at time 408 .
[0050] In another embodiment, the second quality management action initiated at time 410 may be different from the first quality management action launched at time 406 . For example, the second quality management action taken at time 410 may be specific to the occurrence of a plurality of reported quality issues. For example, if users 108 A and 108 B each report a quality issue and common to users 108 A and 108 B is a portion of network 102 (e.g., same type of network (e.g., cellular), usage of the WiFi in building C, etc.), same version of the conference software, and/or other commonality that is not common to users 108 C and 108 D who are not reporting quality issues, then the commonality may be a target of resolution of the quality issue and the second quality management action taken at time 410 .
[0051] It should be appreciated that a single individual user 108 who reports a quality issue may cause network fault isolation or other or similar action, however, as can be further appreciated, having two or more users experiencing quality issue may more readily lead to the culprit of the quality issue. Furthermore, if a certain number or percentage of users 108 , up to and including all users 108 , report quality issues the second quality management action taken at time 410 may be targeted at the source, such as the conference server or other communication and/or presentation component of network 102 . Second quality management action taken at time 410 may also include one or more of notifying a system administrator, launching a troubleshooting application, or, if not already launched, launching a SLA monitoring application. The second quality management action take at time 410 may additionally or alternatively include terminating and optionally restarting the conference. As a further option, restarting the conference may occur upon a changing of a state or setting of server 104 , selection or configuration of network 102 , and/or a setting associated with endpoints 106 designed to remedy the quality issue experienced by the plurality of users 108 .
[0052] Although timeline 400 illustrates a series of events wherein only two users report issues, one at time 404 and the other at time 408 , which result in two quality management actions, one at time 406 and the other at time 410 , additional user reports and/or more, the same, or fewer quality management actions may be taken in response thereto without departing from the disclosure provided herein. For example, three or more users 108 may report quality issues resulting in each causing indicia of their quality to be displayed, such as on status panel 302 . Three or more users may each cause separate quality management actions to be initiated. A number of users 108 above a previously determined threshold may cause a different quality management action to be initiated, such as launching of the SLA, notification of a system administrator application and/or human, or other action. Additionally, the participants, upon seeing icon 314 displayed with respect to a number of users 108 , may mutually agree to terminate the conference or take other action.
[0053] In another embodiment, at least one of first quality management action 406 and second quality management action 410 may comprise, or continue, a speech-to-text application. The resulting transcript produced by the speech-to-text application may be placed (e.g., overlaid) on a portion of the video stream. As a further option, the transcript may be sent via a channel not utilized by the conference, including but not limited to, a series of live blog posts on a website or text messages, emails, etc. sent to one or more endpoints 106 having quality issues or, optionally, to endpoints 106 not having quality issues.
[0054] FIG. 5 depicts second quality management timeline 500 in accordance with embodiments of the present disclosure. Often quality issues are temporary. A component causing the quality issue may be identified action taken to repair, replace, and/or reconfigure the component, often automatically. Load on network 102 and/or server 104 may be strained to accommodate other tasks and once those tasks end, quality of the conference improves. Quality may also improve due to one or more quality management action launched at time 406 and/or 410 or the content of the conference requiring lower quality. In one embodiment, a conference continues at time 502 . At some point thereafter user 1 stops reporting quality issues at time 504 . It should be noted that user 1 of timeline 500 may or may not be the user 1 of timeline 400 , and well as the similarities with user 2, first quality management action, and/or the second quality management action may or may not exist. In another embodiment, at time 504 the user may indicate that conference is of sufficient quality or terminate the reporting of insufficient quality. In response, at time 506 the first quality management action may be discontinued. For example, if endpoints 108 are presenting indicia of the quality signal reported at time 404 and 408 , then the indicia may be removed, replaced, or altered to indicate sufficient quality or the lack of insufficient quality.
[0055] In another embodiment, user 2 stops reporting quality issues at time 508 . Accordingly, at least one second quality management action may be discontinued at time 510 . The second quality management action may be similar to the action taken at time 506 (e.g., stop reporting indicia of low quality to users 108 with respect to user 2). In another embodiment, the action taken at time 510 may be any one or more quality management actions still in place immediately prior to time 510 .
[0056] In another embodiment, timelines 400 and 500 are mixed, such that various combinations of quality issues are reported by a number of users 108 and following or interspersed therein, a number of quality management actions may be taken and, if successful, terminated. For example, a user reports a quality issue at time 404 and first quality management action is taken at time 406 , after some time user 1 may stop reporting quality issues at time 504 and at time 506 the first quality management action terminated. Other orders, additions, and subtractions of the combination of timelines 400 and 500 may be implemented without departing from the disclosure provided herein.
[0057] In the foregoing description, for the purposes of illustration, methods were described in a particular order. It should be appreciated that in alternate embodiments, the methods may be performed in a different order than that described. It should also be appreciated that the methods described above may be performed by hardware components or may be embodied in sequences of machine-executable instructions, which may be used to cause a machine, such as a general-purpose or special-purpose processor (GPU or CPU) or logic circuits programmed with the instructions to perform the methods (FPGA). These machine-executable instructions may be stored on one or more machine readable mediums, such as CD-ROMs or other type of optical disks, floppy diskettes, ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, flash memory, or other types of machine-readable mediums suitable for storing electronic instructions. Alternatively, the methods may be performed by a combination of hardware and software.
[0058] Specific details were given in the description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.
[0059] Also, it is noted that the embodiments were described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function.
[0060] Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium such as storage medium. A processor(s) may perform the necessary tasks. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.
[0061] While illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art. | Conferences are a popular way to hold meetings and presentations when the participants are not required to be physically together. However, the quality of a conference can vary based on a particular user's endpoint configuration, connection, network, conference content, and other factors. Providing a user with the ability to indicate a quality issue, as determined by the user, allows other users and systems to become aware that a user is experiencing quality issues and optionally take action to correct the issue. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2007 022 554.9, filed May 14, 2007; the prior application is herewith incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The invention relates to a device having a pressure roller for feeding printing plates to a plate cylinder and for pressing a printing plate against a surface of the plate cylinder in order to ensure that the printing plate is mounted correctly. The invention also relates to a printing unit having the device.
[0003] Such a device is known from German Published, Non-Prosecuted Patent Application DE 100 01 328 A1. In order to compensate for a bending of a pressure roller and thus to achieve a better pressure distribution of the pressing force, the pressure roller therein is cambered or disposed at an angle with respect to the plate cylinder axis.
[0004] A further pressure roller is disclosed in European Patent Application EP 0 679 513 A2, corresponding to U.S. Pat. No. 5,738,015. In that device, the pressure roller is formed by a number of segment disks disposed at equal distances from each other.
BRIEF SUMMARY OF THE INVENTION
[0005] It is accordingly an object of the invention to provide a device for feeding printing plates to a plate cylinder and a printing unit having the device, which overcome the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and which provide an alternative pressure roller that allows compensation for uneven pressing forces caused by a bending of the pressure roller.
[0006] With the foregoing and other objects in view there is provided, in accordance with the invention, a device for feeding printing plates to a plate cylinder. The device comprises a pressure roller disposed axially parallel to the plate cylinder for applying pressure to the printing plate. The pressure roller includes cylindrical segments having different axial widths.
[0007] A particular advantage of the invention is that the pressing forces that the pressure roller applies to the printing plate to be mounted are constant across the width of the printing plate. As a result, correct positioning of the printing plate on the plate cylinder is ensured.
[0008] In accordance with another feature of the invention, the pressure roller is formed by segments that have different widths and are spaced apart from each other and the widths thereof become smaller from the center towards the ends of the roller.
[0009] With the objects of the invention in view, there is also provided a device for feeding printing plates to a plate cylinder. The device comprises a pressure roller disposed axially parallel to the plate cylinder for applying pressure to the printing plate. The pressure roller includes cylindrical segments having different diameters.
[0010] In accordance with a further feature of the invention, the segments have different diameters and the spaced-apart segments disposed at the center having a larger diameter than in the end regions.
[0011] With the objects of the invention in view, there is furthermore provided a device for feeding printing plates to a plate cylinder. The device comprises a pressure roller disposed axially parallel to the plate cylinder for applying pressure to the printing plate. The pressure roller includes cylindrical segments disposed at different distances between the segments.
[0012] In accordance with an added feature of the invention, the cylinder-shaped segments have the same width, but the distances between the segments advantageously vary, that is the distances at the center of the pressure roller are smaller than in the end regions.
[0013] In accordance with an additional feature of the invention, metal sleeves may be provided between the segments to make the shaft more rigid. As a result, bending of the pressure roller is minimized.
[0014] With the objects of the invention in view, there is concomitantly provided a printing unit of a rotary printing press. The printing unit comprises a device according to the invention.
[0015] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0016] Although the invention is illustrated and described herein as embodied in a device for feeding printing plates to a plate cylinder and a printing unit having the device, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0017] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0018] FIG. 1 is a diagrammatic, longitudinal-sectional view of a sheet-fed printing press;
[0019] FIG. 2 is an enlarged, sectional view of a printing unit;
[0020] FIG. 3 is a fragmentary, partly-sectional, front-elevational view of a plate cylinder including a pressure roller for a printing plate;
[0021] FIG. 4 is a view similar to FIG. 3 of a plate cylinder including an alternative pressure roller for a printing plate; and
[0022] FIG. 5 is a view similar to FIGS. 3 and 4 of a plate cylinder including a third embodiment of the pressure roller for a printing plate.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a machine, for example a printing press 1 , for processing sheets 7 . The printing press 1 includes a feeder 2 , at least one printing unit 3 , 4 , and a delivery 6 . The sheets 7 are taken from a sheet stack 8 and are fed across a feed table 9 to the printing units 3 and 4 individually or in shingled formation. Each printing unit includes a plate cylinder 11 , 12 and a blanket cylinder 15 , 20 cooperating with the respective plate cylinder 11 , 12 as is known in the art. Each of the plate cylinders 11 , 12 includes a device 13 , 14 for mounting flexible printing plates. In addition, a device 16 , 17 for semiautomatic or fully automatic plate changing is associated with each of the plate cylinders 11 , 12 .
[0024] The sheet stack 8 rests on a stack plate 10 that can be lifted in a controlled manner. Sheets 7 are removed from the upper side of the sheet stack 8 through the use of what is known as a suction head 18 , which includes, among other elements, a number of lifting and dragging suckers 19 , 21 for separating the sheets 7 . In addition, blowers 22 for loosening the upper sheet layers and sensing elements 23 for initiating a lifting of the stack are provided. A number of lateral and rear stops 24 are provided for aligning the sheet stack 8 , in particular the upper sheets 7 in the stack 8 .
[0025] FIG. 2 represents a printing unit 3 including a device 16 . The device 16 basically includes a pressure roller 27 , which is disposed at a short distance from the circumferential surface of the plate cylinder 11 and is parallel to the plate cylinder 11 . As is seen in FIGS. 3 , 4 and 5 , the pressure roller 27 can be engaged with the circumferential surface of the plate cylinder 11 in order to feed a new printing plate 26 . The pressure roller 27 is preferably driven by friction rollers 28 , 29 that are brought into contact with what are known as bearer rings 31 , 32 of the plate cylinder 11 when the pressure roller 27 is engaged with the plate cylinder 11 and are driven by friction.
[0026] Alternatively, the pressure roller 27 may be driven by an electric motor or by a gearing mechanism or by the printing plate itself.
[0027] In a first embodiment, which is shown in FIG. 3 , the pressure roller 27 is formed of a shaft 33 that is supported for rotation and carries a number of cylindrical segments 34 , 35 , 36 that are spaced apart from each other and fixed to rotate with the shaft 33 . The segments 34 that are located at a central region of the shaft 33 have a greater axial width B 1 than the segments 35 , and the latter have a greater width B 2 than the segments 36 , which are located at end regions. Thus, in theory, when the pressure roller 27 is engaged with the printing plate 26 disposed on the plate cylinder 11 , different pressing forces occur as a function of the widths B 1 , B 2 , B 3 of the segments 34 , 35 , 36 . At the same deformation, the wider segments 34 generate a stronger force. As the pressure roller 27 is bent by the pressure forces, the deformation and consequently the pressing force is smaller at the center of the plate. The wider segments 34 at the center of the pressure roller 27 compensate for these smaller forces to ensure a uniform pressing force of the different-width segments 34 to 36 against the printing plate 26 .
[0028] In a second embodiment, which is shown in FIG. 4 , cylindrical segments 37 , 38 , 39 are provided that have the same axial width, but different diameters D 1 , D 2 , D 3 . The diameters D 1 of the segments 37 at the center are larger than that of the segments 39 disposed in the end regions. It may also be seen that some of the segments 38 , 39 are optionally tapered toward a respective end of the pressure roller 27 .
[0029] In a third embodiment, which is shown in FIG. 5 , cylindrical segments 42 that have the same width and the same diameter are disposed at different distances L 1 , L 2 , L 3 from each other. The distances L 1 between the segments 42 disposed at the center are smaller than the distances between the segments 42 disposed in the end regions.
[0030] In order to minimize bending of the pressure roller 27 , it is proposed to reinforce the roller 27 by providing respective reinforcement sleeves or bushings 41 between the individual segments.
[0031] Furthermore, the pressing force upon bending can also be controlled through the hardness of the segment material. In this context, foamed material with different pore sizes can be used.
[0032] An alternative construction is to introduce axially parallel bores to make room for the segment material to escape into.
[0033] An optimized embodiment includes a combination of segments 34 , 35 , 36 with different widths B 1 , B 2 , B 3 , segments 37 , 38 , 39 with different diameters D 1 , D 2 , D 3 , or segments 42 with different distances L 1 , L 2 , L 3 therebetween. | A device for feeding printing plates to a plate cylinder includes a pressure roller for pressing the printing plate against the circumferential surface of the plate cylinder when the printing plate is being mounted. In order to compensate for uneven pressing forces resulting from a bending of the pressure roller, cylindrical segments are provided that have different widths and/or different diameters and/or different distances between the segments. A printing unit of a rotary printing press having the device, is also provided. | 1 |
FIELD OF THE INVENTION
[0001] This invention relates to power return tape measures, in general, and to such tape measures as are especially suited for use by a vinyl siding mechanic, in particular.
BACKGROUND OF THE INVENTION
[0002] Power return tape measures are known in the art. Whether they be ¼″, ½″, ¾″ or 1″ wide, such measures employ blades graduated in {fraction (1/16)}″ increments with end hooks oftentimes re-inforced. Typically constructed of tempered high carbon steel, the blades oftentimes employ additional load bearing rivets at the end hook to reduce blade edge breakage, and are usually housed with an impact resistant case, frequently with a belt clip on its back side. As will be readily appreciated, power return tapes of this type find favor in the carpentry field and in the vinyl siding industry.
[0003] As will also be appreciated, vinyl siding mechanics oftentimes find themselves working on ladders—frequently for extended periods of time. Under such conditions, it is not unusual for the mechanic to drop the piece of siding he is working with, or the hammer he is using, or the nails he is hammering. On such occasions, the typical routine is for the worker to stop what he or she is then doing, climb down the ladder, retrieve what has fallen, and climb back up to continue working again. Moreover,experience has shown that this routine takes place about once every 45-60 minutes. When working at a height which can well be 20-25 feet, this repeated process of climbing down, retrieving, and climbing back up again can be quite arduous especially where the mechanic is either working alone, or where an assistant is away working at a different location at the property.
SUMMARY OF THE INVENTION
[0004] As will become clear from the following description, a power return tape according to the invention is in the form of a measuring tape having a case, a blade wound within the case and graduated in marked increments, and an exposed hook at one end of the blade for unwinding the blade and drawing it out from the case. In accordance with the invention, at least one of the exposed hook and a length of blade adjacent to the hook cooperate in forming a grasping tool for fallen objects, separate and apart from employing the marked increments of the blade in linear measurement. In such respect, the measuring tape proves particularly attractive for mechanics working at the top of ladders, and/or at other heights from which such objects may accidentally drop.
[0005] In accordance with a preferred embodiment of the invention, the cooperation which exists between the exposed hook and the length of blade so drawn enable the grasping of these fallen objects independently of the length of the blade which has been drawn from the case. In one configuration, the blade itself may be of a metallic fabrication, so as to be able to twist and bend to a prescribed shape in, for example, grasping a hammer which has fallen or a piece of vinyl siding, in being retrieved. In another configuration, the blade can be provided with one or more of a series of slots, in arranging for the exposed hook to loop around the blade to be received and held when fitted therethrough to allow grasping from the elevated height, as when the hook is looped under the blade. Where lighter items are required to be retrieved—as a nail—the exposed hook can be magnetized, in accordance with the invention, and may be configured substantially orthogonal, from top to bottom. Where the fallen object is of a type having an opening to be fitted into when grasped, the exposed hook, on the other hand, may be one which tapers inwardly from top to bottom, whether or not it is magnetized. In certain instances, and in accordance with the invention, the exposed hook, itself, could be arranged to swivel at its join with the blade end, in allowing for the establishment of a further slot opening of variable thickness in grabbing onto that which is then laying on the ground, for lifting back to the mechanic.
[0006] In another instance of the invention, for grasping a larger tool such as a hammer—instead of a smaller item (as a plumbing fitting) which can be raised through magnetic attraction—a further embodiment of the invention employs a sheath at a bottom of the case through which the blade passes when drawn. The sheath is there extendable and pliant to retain the prescribed shaped to which the sheath is twisted and bent in forming the grasping end to hold onto the dropped item. In such construction, a tab may additionally be included, coupled to the sheath, as an aid in drawing the sheath out from the bottom of the case.
[0007] Alternatively, to raise a fallen large object as a screwdriver, pliers, or other tool, an adhesive strip may be included at an underside of the case having a like tab portion through which the blade passes when drawn by the exposed hook. With the adhesive strip being extendable via the tab, and with the strip being peelable forwardly of, and around, the end hook for securement at a top surface of the blade, the object can be retrieved. In this respect, a further feature of the invention envisions a plurality of these adhesive strips, one below the other, each of which is individually peelable forwardly and around the exposed hook for grabbing onto the fallen object, with each adhesive strip being discardable afterwards on an individual use basis. In accordance with the invention, the length of blade adjacent to the hook may be of whatever length is required in effecting the “picking-up” action, and when a sheath or adhesive is employed in so doing, such appurtenances may be of the order of 2-5″ in length.
[0008] Thus, and as will be seen more particularly from the following description, the power return tape of the invention serves a purpose other than just one of linear measurement—namely, one which allows for retrieval of fallen objects without the need for a mechanic working at a height to continually climb down from that height, or from the ladder then being used, only to retrieve the item and then climb back up to continue performing anew. With the pick-up measuring tape of the invention, therefore, a significant amount of time and energy is substantially saved, along with the inconvenience otherwise associated with it.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] These and other features of the present invention will be more clearly understood from a consideration of the following description, taken in connection with the accompanying drawings, in which:
[0010] [0010]FIG. 1 is a perspective view of a power return measuring tape known in the prior art;
[0011] [0011]FIG. 2 is a perspective view of such a measuring tape embodying the present invention in its employment of the blade-surrounding sheath, along with other alternative arrangements of the invention;
[0012] [0012]FIG. 3 is a perspective view of a power return measuring tape helpful in the understanding of a construction of the invention employing the adhesive strip feature; and
[0013] FIGS. 4 - 5 are helpful in an understanding of other embodiments of the present invention in forming a grasping tool of the tape separate and apart from its employment in making linear measurements.
DETAILED DESCRIPTION OF THE INVENTION
[0014] In the perspective views of FIGS. 2 and 3, the power return measuring tape of the invention includes a case 12 , a blade 14 wound within the case 12 , graduated in marked increments 16 , 18 , typically {fraction (1/16)}″ apart in well known manner. An exposed hook 20 is secured to the end of the blade 14 by load bearing rivets 22 to reduce blade edge breakage. A positive locking slide mechanism is shown at 24 once the blade 14 is drawn out from the case 12 . In accordance with the invention, the blade 14 is of a metallic fabrication—preferably tempered high carbon steel—while the case 12 may be constructed to be impact resistant, as with a chrome plate, and with a handy belt clip, for example, on its back side (not shown). Such power return measuring tape may be of ½″, ¾″, or 1″ width, and of blade lengths of 12-30 ft. in length, or longer. As with these power return tapes known to the prior art and as shown in FIG. 1, the blade 14 may be chemically treated so as to be resistant to abrasion and pitting, and to be significantly unaffected by moisture, acid or caustic solution. As will be appreciated, the blade 14 may be “colored” for high visibility, and may be concave shape to allow for extension without buckling.
[0015] In accordance with one aspect of the invention, at least one of the exposed hook 20 and a length of the blade 14 adjacent to the hook 20 are further arranged to form a grasping tool of fallen objects separate and apart from the employment of the return tape and its increments 16 , 18 in linear measuring. Thus, besides the blade 14 being of metallic fabrication, it is selected of a fabrication pliant to twisting and bending to a prescribed shape—so as to allow a mechanic to configure the blade in a manner to utilize it in whatever shape is needed to retrieve a fallen object, independent of the length of blade drawn out from the case 12 by the hook 20 . In this respect, the exposed hook 20 can also be magnetized to assist in picking up nails and other light metallic objects from an extended height.
[0016] Illustrated in FIG. 2 as having sides 30 , substantially orthogonal from top to bottom, the hook 20 may alternatively be constructed with sides 32 which taper inwardly from top to bottom—to assist in fitting within slots or other openings of fallen objects to be retrieved (FIG. 4). Similarly, and as shown in FIG. 5), the orthogonally sided hook 20 of FIGS. 2 and 3 could be replaced, instead, by a hook 29 which includes a first downwardly extending portion 34 and a second angled portion 36 which extends upwardly in essentially serving as a claw to grasp the fallen object. On the other hand—and in accordance with the embodiment of the invention shown in FIG. 2—the exposed hook 20 may be swivelably joined at the end of a blade whose lower end 37 slopes away in forming a slot 38 of a thickness variable in accordance with a swivel of the downwardly extending portion 39 about a pivot point 40 . The fallen object could thus be aligned to fit within the slot 38 for purposes of being grasped and retrieved, and once recovered by the mechanic, the hook 20 is returned to its initial position for measurements once again against the bearing surface 41 of the downward portion 39 .
[0017] Other configurations can similarly be substituted while continuing to employ the end hook 20 along with a length of the blade adjacent to it in forming a grasping tool. Thus, a double sided adhesive could be affixed either at the forward end 43 of the hook 20 of FIG. 2, or to its opposing surface 45 , or to either the top side or underside of the tape 14 —as at 47 or 49 , respectively.
[0018] The arrangements of FIGS. 2 and 3 illustrate another possible embodiment according to the invention, in which a plurality of slots 50 , 51 , 52 . . . are formed within the surface of the blade 14 into which the end hook 20 is arranged to fit—and received and held in place by one such slot once the hook is looped around the blade 14 after it is drawn from the case 12 . In the configuration of FIG. 3, the hook 20 could be looped under the blade 14 to the slot 50 in forming the grasping tool for a hammer separate and apart from the employment of the power return tape as a measuring tool and independent of the length of blade drawn out from the case. By fabricating the blade 14 to be pliant so as to sustain the twist and bend to the prescribed shape for facilitating the fallen object to be picked up, this feature of the invention will be more readily understood.
[0019] In the arrangement of FIG. 2 for forming this grasping tool for a larger object, the power-return measuring tape of the invention may alternatively include a sheath 55 secured at a bottom of the case 12 and through which the blade 14 passes when drawn out, with the sheath being extendable by a tab 57 coupled to it at its end. Such sheath 55 may be adhesively secured with the case 12 (as at 59 ), and of a length of some 2″-5″ fabricated of a “shape retentive” material once twisted and bent to that configuration that would best enable the mechanic on a ladder or other height to load the sheath adjacent the end hook 20 —and then extend the end hook 20 to draw out the blade 14 the needed length to reach the object on the ground. Once the object is grasped and held by the looped configuration of the sheath 55 , the slide mechanism 24 is actuated to return the blade into the case 12 in retrieving the hammer, plier, etc.—at which time the mechanic simply unravels the loop so formed and returns the sheath to its original position.
[0020] In the configuration of FIG. 3, on the other hand, an adhesive strip 60 may be secured at an underside of the case 12 , with its own tab extension 62 through which the blade passes when drawn, and with the adhesive strip 60 being extendable towards the end hook 20 in likewise forming the shape best suited for object retrieval. Such adhesive strip 60 may be of double-sided tape, and peelable forwardly around the end hook 20 for securement at a top surface of the blade 14 , as shown at the left side of FIG. 3. In such configuration, furthermore, a plurality of such adhesive strips may be stacked as at 64 , one atop the other (as at the right side of FIG. 3), and individually peelable in separation, to be looped around the end hook 20 , over and about the fallen object to be grasped and retrieved. After so doing, as will be appreciated, that adhesive strip, of double-sided tape configuration used, could then be discarded in awaiting an occasion to employ the next one in the stack.
[0021] While there have been described what are considered to be preferred embodiments of the present invention, it will be readily appreciated by those skilled in the art that modifications can be made without departing from the scope of the teachings herein of using a power return measuring tape to do more than just serve for purposes of linear measurement, but to incorporate either or both of its end hook and blade for purposes of lifting and retrieval. While useful in the construction field for different types of mechanics, such power return tape will be understood to be particularly useful for vinyl contractors whose type of operation oftentimes results in items being dropped. With the power return tape of the invention serving as a “pick-up” device in addition, such problem is easily overcome—and for such reason, therefore, resort should be had to the claims appended hereto for a true understanding of the scope of the invention. | A power return tape in the form of a measuring tape including a case, a blade wound within the case graduated in marked increments, an exposed end hook at one end of the blade for unwinding the blade and drawing it from the case, and with at least one of the exposed hook and a length of the blade adjacent thereto cooperating to form a grasping tool for falling objects, in a manner separate and apart from the employment of the marked increments on the tape in making linear measurements—and particularly attractive for mechanics working from ladders and/or at other heights. | 6 |
This invention relates to an internal combustion engine and more particularly to an engine which combines the advantages of magnetohydrodynamics and six cycle rotary valve engines. The latter were shown and described in U.S. Pat. No. 3,392,220 dated July 1, 1975 and U.S. Pat. No. 4,037,572 dated July 26, 1977 of the same inventor.
BACKGROUND OF THE INVENTION
New engine adaptations and designs are being studied and developed to attempt to improve the traditional combustion process, mainly the four stroke combustion system. Some examples of the adaptations are revisions in carburation techniques, fuel consumption monitoring, alterations in combustion chamber aerodynamics, basic engine configurations such as the rotary engine, vaporization and ionization of fuel for more complete combustion, new exotic fuels, and other processes. While these are all worthwhile endeavors and knowledge is gained through these efforts, the basic problems are not solved and the basic variables of these engines' operation are not fully coordinated.
In all engines there are four fundamental variables that must be worked with in various ways so they complement each other to produce desirable results. These variables are time and temperature of combustion, density of the gas and area of the combustion chamber. The desirable results are complete combustion with a relatively low exhaust temperature. Density is the easiest variable to manipulate through adjustments in liquid flow. The other three are more difficult.
At a given temperature there must be sufficient time to complete combustion. The lower the temperature the longer the time for complete oxidation. The higher the temperature the shorter the time for oxidation. This temperature variable has certain upper and lower limits. A temperature of 3200 degrees C. appears to be the upper limit of combustion without NO 2 formation in an unrestricted environment, and 5500 degrees C. is the highest temperature achievable by a chemical reaction.
A measure of efficiency of an engine is the relationship between the highest temperature allowed minus the output temperature of exhaust divided by the first temperature. Therefore it is impossible here on earth to get an absolutely efficient temperature relationship because the exhaust temperature can never be below outside air temperature. To be at top efficiency the exhaust temperature would have to be absolute zero. The six cycle configuration takes care of these temperature limitations.
Temperature also has a relationship with pressure. This relationship is dependent on the density of the gas involved; temperature being a measure of the average kinetic energy of the gas. A gas with low density can have molecules with very high velocity and still have low pressure, but this same gas with high density and the same velocity would have high pressure and a high temperature. The average kinetic energies of the high and low density examples are the same; only their densities and pressures have changed. These variables can be switched around to achieve similar results along different paths.
The time of combustion is just as critical as temperature to achieve the desirable result of total oxidation and extraction of energy from a given unit of fuel. Given the limits of temperature there is just not enough time in present engine designs to give complete oxidation no matter what the mixture setting. The time to oxidation ratio gets even worse as increases of throttle and power settings are offset by higher rpm's due to the relatively unchanging size of the combustion chamber. It may be somewhat better under load conditions.
A continuous time of oxidation is probably ideal, such as presented in steam and turbine engines, but they have problems with the other variables, e.g. area and heat transfer, density and disassociation. They also have mechanical limitations of valving, power strokes related to rmp, heat resistent materials, and lubrication breakdown at extreme temperatures and exposure to the products of combustion (silicone based oils). The variable of time is also handled by the six cycle configuration.
Increasing the amount of time in a combustion chamber involves increasing the surface area of the chamber. The ratio of volume to area in a sphere or even a cylinder is a disproportionate one. Increasing the volume of space enclosed by a sphere or cylinder by a unit does not increase the surface area of that enclosure by the same unit, but by a fraction of a unit. Any surface area is detrimental to some extent. The kinetic energy of the molecules is diminished when they touch this surface.
When time is increased, oxidation is enhanced, but surface area is increased and heat loss is increased. This is at the heart of the problems involved in engine designs, internal and external. The question is "How are the fuel, oxygen and combustion products, and their kinetic energy and velocity separated from the surface area of the combustion chamber?" "How are they to be insulated inside the chamber?"
OBJECTS AND STATEMENT OF THE INVENTION
These questions are answered by the improvements of the present invention, which cause flows of electrons to pass through the gas in the chamber in special configurations. These electrons will break loose electrons in the gas, giving these molecules a positive charge and creating a gas that can carry electric currents. These flows of electrons then have their own magnetic fields, which surround the gas and insulate it from the containing surface area. Combustion further ionizes the gas, reducing the resistance to the electron flow. The resulting magnetic field effects all the variables of time, temperature, area and disassociation (density). The exhaust gases are also ionized and provide the means to generate the necessary amounts of electricity to energize the combustion chamber gases. A balance is reached between cost of energy to produce the electron flow through the MHD generator and the benefit the magnetic fields produce through energy saving in stopping heat transfer to the surface area of the combustion chamber.
The application of magnetohydrodynamics (MHD) to the internal combustion engine as above described is new and advantageous.
The principles of magnetohydrodynamics working on the variables of area and temperature and the six cycle configuration working on the variables of time and temperature provide a truly unique engine.
The engine is very small, extremely light, has an exceptionally good fuel efficiency, is pollution free and, with optimum results, would have no water jacket and still be cool to the touch, with a cool exhaust.
BRIEF DESCRIPTION OF THE FIGS.
These and other advantages of the present invention will be more fully understood in the following detailed description, taken together with the drawings in which
FIG. 1 is a top view of the engine in accordance with the invention, shown in partial section.
FIG. 2 is a front view of the engine, shown in partial section.
FIG. 3 is a plan view of the piston face, showing the array of electrodes.
FIG. 4 is a side sectional view of the piston, taken along the lines 4--4 in FIG. 3.
FIG. 5 is a plan view of the commutator.
FIG. 6 is a side view of the commutator, shown in partial section.
FIG. 7 is a schematic diagram of the overall electrical system.
FIG. 8 is a schematic of the six cycles of the engine, showing concurrent piston and valve positions and emphasizing the relationship between the intake port and the primary exhaust port.
FIG. 9 is a side view of the magnetohydrodynamic generator, shown in partial section.
FIG. 10 is a sectional view of the magnetohydrodynamic generator, taken along lines 10--10 in FIG. 9.
FIG. 11 is an end view of the piston magnet.
FIG. 12 is a sectional view of the piston magnet, taken along lines 12--12 of FIG. 11.
FIG. 13 is an end view of the piston with the piston magnet removed, showing the piston arm, contacts and side buses.
FIG. 14 is a sectional view of the piston arm, taken along the lines 14--14 in FIG. 13.
FIG. 15 is a side view of the cylinder lining and its embedded coil, shown in partial section.
FIG. 16 is a side view of the timing disk with associated magnets and pickup coils.
FIG. 17 is an end view of the timing disk with associated magnets and pickup coils.
FIG. 18 is a side view of the timing disk with associated lights and photo cells in accordance with a second embodiment of this aspect of the invention.
FIG. 19 is an end view of the timing disk with associated lights and photo cells.
FIG. 20 is an electrical schematic, shown in detail.
FIG. 21 is a representation of the longitudinal magnetic fields, as seen looking through the cylinders.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1-6, the engine according to this invention is shown generally as 10. The engine comprises a block 11 having two cylinders 12, each having a pair of opposed pistons 13, connected by connecting rods 14 and cranks 15 to gears 16. A magnetohydrodynamic generator 17 is secured at one side of the engine 10 and is connected to the secondary exhaust manifold 18 of the engine. The primary exhaust/intake manifold 19 of one cylinder is arranged to input with the next cylinder. The primary exhause/intake manifold 19 has a glass dielectric lining 131. Similarly the secondary exhaust manifold 18 has a glass dielectric lining 132. A commutator 20 within a commutator cover 21 is connected by an arm 22 to each piston 13. An exhaust pipe 28 leads from the generator 17 to the outside air.
Mounted above the block 11 centrally over the cylinders 12, are rotary valves 23, the purpose and functions of which are described in my earlier U.S. Pat. No. 4,037,572, dated July 26, 1977. A control center 24, to be more fully described, is also mounted over the block 11 and is associated with each cylinder 12.
Each cylinder has a nonconducting glass lining 25.
The block 11 is shown with a coolant jacket 26. If some heat is transferred to the cylinder walls 25, a coolant jacket 26 will remove this heat. If the magnetic fields are generated so that heat is not transferred to the cylinder walls, no coolant is needed. Then there would be no need for the radiator, coolant pump, thermostat, hoses, or fan and their accompanying energy drain and oil would be directed through the rotary valve 23.
Each crankcase has provision for commutators 20 which are mounted on their respective crankcase 67. A slot 77 for the intrusion of the piston arm 22 is placed on the crankcase. Surrounding this slot 77 are seals 31 to prevent oil from entering the area above the slot. These seals press against the slide to be described. On either end of the slots 77 and seals 31 are oil drain holes 32 which provide a means for any oil that gets past the seals 32 to return to the crankcase 67. Of course as in all engines this crankcase is vented. In addition to its own mounting holes each crankcase has mounting holes 96 for the slide cover 97 and unit cover 21.
Each piston 13 contains an arm 22. The purpose of this arm 22 is to connect the piston electrically to the engine. It contains two insulated buses 98, 99 that connect the brushes 76 to the piston electromagnet 79, electrodes 80, 82 (bus 98), and piston face 81 (bus 99). It is permanently attached to or cast with the piston body 88 itself.
The piston body 88 also has a weight or mass 100 cast with it to balance the moment of the arm 22. The mass 100 is placed opposite of the arm on the piston body 88.
The piston body 88 also has its front inner surface 101 threaded to receive the piston face unit 102. The piston without this unit is essentially a hollow tube threaded on the inside at one end and containing the piston arm 22 and moment mass 100 on the other.
The piston face unit 102 is threaded on its outside surface to match the threads on the piston body 88 and has face 81 on its front, an electron conducting metal. This lining face 81 has protruding from it in a circle and at the center, the surfaces of the electrodes 80, 82.
The electrodes 80, 82 are a part of the electromagnet's core 83 but insulated from it by insulation 103 and are all connected to the center of the core 78 where they come in contact with the arm bus 22. The shape of these electrode ends is a dome as it protrudes from the face lining 81.
Another part of the face unit 102 is the electromagnet 79. The core 83 of the electromagnet 79 contains the insulated electrodes 80, 82 and is made of iron. The energizing means of this magnet is the standard copper coil 74. This wire coil is wrapped around the central core 83 of iron and in the correct direction so that the positive charge of the magnet faces the combustion chamber.
The commutator 20 solves the problem of transferring electricity to and from the pistons 13 without interference from engine oil. The pistons 13, connecting rods 14, and crankshaft 15 are essentially free floating on an oil film and constant metal electrical contact needed is not present. Also an oil film serves as an electron insulation.
The piston arm 22 is inserted through the crankcase slot 77. There are two electroplates 75 on either side of the arm 22 and are connected to the top of the slide cover 97. These plates 75 have their cover 21 that encloses the whole unit.
The brushes 76 slide on these electroplates 75, one brush for one plate, and are attached to the piston arm 22. These brushes 76 are electrically connected to their respective bus 98, 99 in the arm 22 and are under tension, pressing on the plates. This tension is provided by springs 104 placed above the brushes and under the brush cover 105 which is attached with screws to the piston arm 22. These springs 104 provide pressure to the plates 75 as well as compensate for small variations in vertical movement in the arm due to piston jar in the cylinders. This is very small in the piston itself but amplified through the arm 22 because of its length.
The slide cover 97 is below the electroplates 75 and has a slot 77 through which the piston arm 22 passes. This cover has seals 31 around the slot 77 on the bottom side and is mounted to the crankcase 67.
A slide 106 is located under this cover 97 and moves back and forth between the seals 31 on the slide cover 97 and the seals 31 on the crankcase 67. In the center of the slide 106 is a hole 107 through which the piston arm 22 passes and this hole is rubber lined 108 to seal any oil from passing. This slide 106 moves back and forth with the piston arm 22 preventing oil from passing from the crankcase slot onto the electroplates 75 and brushes 76.
The fuel system and sequences will be described with particular reference to FIG. 8.
The fuel can arrive from the storage tank in two ways (not shown). The first is by the standard line and fuel pump. The second method, assuming a liquid such as gasoline or diesel is used, is to use a vacuum pump and reduce atmospheric pressure in the storage tank to the point of boiling the fuel in the tank at outside air temperature. Either the fuel pump or the vacuum pump then transfers the fuel in whatever state to the metering device which meters the fuel to the engine.
There are several metering devices and varying types of each device. These devices include carburetors, injectors and gas meters. Although these attachments are necessary to this engine, it is not of significance which device is selected because they deal mainly in the variable density and the six cycle configuration allows time for low grade fuel and unburned fuel to be refined and completely burned. The fuel is then burned in the oxidation sequence.
Each rotary valve 23 has an intake port 27 on one side, which connects the cylinder 12 to the intake manifold 19 during the intake cycle, and a primary exhaust port 29, and a secondary exhaust port 30 on the other side, which connects the cylinders 12 to the primary exhaust/intake manifold 19 and the exhaust manifold 18, respectively, during appropriate cycles of the six cycle process. Primary exhaust is partially ionized and very dirty and is directed through the primary exhaust port 24 through its own passage 129 in the engine to the primary exhaust/intake manifold 19. The primary exhaust/intake manifold always has a few pounds of vaccuum negative pressure and primary exhaust has opposite pressure so flow will readily exist. The vast majority of molecules that end up in primary exhaust go through the combustion process three times. First, in primary combustion in cylinder 1, then transferred over to cylinder 2 in intake and combusted again in the second cylinder's primary combustion, then combusted again in the second cylinder's secondary combustion, before it is exhausted through exhaust passage 130 in the engine into and through the secondary exhaust manifold 18.
Primary exhaust serves two purposes for combustion. It releaves pressure at the end of primary combustion. This further cools the combustion gases and partially removes incomplete combusted products to the point that temperature and density of fuel are below the ignition requirements when the turbine injects fresh oxygen preparing for secondary combustion.
Since primary exhaust is ionized it further serves an electrical function in that it allows energy to be saved in primary combustion. The electrons flowing between the pistons 13 can more easily find their way and further the magnetic task. This helps divide the energy produced by the magnetohydrodynamic generator 17 operating only on secondary exhaust, between primary and secondary combustion. The glass dielectric lining 132 on the secondary exhaust manifold 18 prevents errant electrons from dionizing secondary exhaust gas, which would have a negative effect on the function of the engine. The glass dielectric lining 131 on the primary exhaust/intake manifold 19 prevents dionizing of the primary exhaust. The six stages shown in FIG. 8 for each position of the rotary valves are at the beginning of the piston stroke.
As the pistons 13 move apart in the intake stroke (stage 1 for cylinder 1) air enters the chamber 12 through the intake port 27 along with partially burned and partially ionized fuel from the primary exhaust through the primary exhaust port 29 in the accompanying cylinder 2. As the pistons 13 approach the end of this stroke a small amount of air enters the chamber through the side ports 33 in the cylinder supplied by a turbo-charger 34. If a carburetor or gas meter is used the fuel charge will also have entered through the intake port 27 at this time.
The primary compression stroke (stage 2 for cylinder 1) then begins. The pistons come together and compress this mixture of gases that already have a small amount of ionization from the primary exhaust gases included.
Primary power stroke (stage 3 for cylinder 1) then begins. At this point the electrodes 80, 82 are energized and electrons begin beaming from one electrode to its mate in the opposite piston which are almost touching. Also if the engine is injected, the fuel will be forced into the chamber at this time. As the electrons begin to beam across, they ignite the fuel air mixture. Ionization begins to develop rapidly as electrons are bumped off their atoms by the beam of electrons coming from the electrodes and by the force of the oxidation process itself. As this process begins the combustion gases become charged with a positive sign since electrons are negative. Also at this point electromagnets in the pistons 13 (to be more fully described) are energized with the positive side of the magnet facing the combustion chamber repelling the positively charged gases from the piston faces, creating force. Finally at this point a magnetic field begins to surround the combustion gases preventing them from touching the surface of the cylinder 12 and transfering their kinetic energy to the cylinder. The gases are contained, with the pistons 13 being forced apart ideally only through magnetic force working against expanding gases.
As the burning progresses the beam of electrons continues and becomes stronger as more ionization occurs, making a better conductor. Then as the pistons 13 reach their extended position and the port 33 for the incoming air opens, with the turbo blocked off because of the cylinder pressure, the electric current or beam of electrons is reduced by a rheostat (to be more fully described) and the magnetic field strength balanced with the expanding and cooling gases of primary combustion. At this point the primary exhaust port 29 begins to open, further reducing pressure in the cylinder 12 and allowing fresh air from the turbo to enter the chamber. At this point the fire in the cylinder 12 is put out because of insufficient heat to maintain combustion. Finally at full extension of the pistons the current is turned off.
Secondary compression then begins (stage 4 of cylinder 1). During this stroke the electrodes are turned off.
The secondary power stroke (stage 5 of cylinder 1) now begins with the same electrical functions used in the primary power stroke. The exhaust stroke (stage 6 of cylinder 1) then finishes the oxidation sequence.
The engine turbine 34 is geared to a timing gear on the shaft of the rotary valve 23. It provides fresh air to the cylinder through the cylinder ports or slots 33 at a low pressure. It does not force air into the chamber but only makes air available to the chamber when it is ready to accept it. These times are at the end of the intake stroke (stage 1) and the beginning of the secondary compression stroke (stage 4).
Even though the cylinder port 33 is opened by the piston 13 by its position at the beginning of the primary compression stroke the turbine 34 will not be providing air at this time because the pressure in the cylinder 12 will have equalized between the cylinder 12 and the turbine 34. Therefore, air is only being introduced at the end of the intake stroke when the pressure in the cylinder 12 is less than that produced by the turbine 34 no matter what the rpm.
The same holds true at the end of the primary combustion (power) stroke and the beginning of the secondary compression stroke. At the end of primary combustion when the side ports 33 start to open there is pressure in the cylinder 12, much reduced now as compared to the beginning of the stroke, and this pressure prevents air from entering the cylinder. A little later the primary exhaust port 29 begins to open reducing pressure in the cylinder 12 to the point of allowing the turbine pressure to insert fresh air into the cylinder.
Under load conditions where cylinder pressure is not matched by equal increase in rpm, the pressure produced by the turbine 34 must increase. This is done by the standard waste gate linked to the throttle as used in most turbo-chargers.
The electrical system is next with reference to FIGS. 7, 9 and 10 described. The electricity used in this engine is produced and used by units which are dependent on each other for their electrical function. It is a balanced system with a circular interaction. Therefore a beginning is really not the beginning but a point chosen for beginning. A point to start is the magnetohydrodynamic (MHD) generator 17. The electrons are set in motion here by the magnetic field produced by stationary magnets acting upon the moving ionized gas in the exhaust.
A MHD generator produces movement of electrons (electricity) by passing a magnetic field at a right angle through a moving ionized gas. The generator as shown has several features for efficient electrical production. The first feature is the ionized gas container 34.
This is a pipe, which comes from the glass lined exhaust manifold, has four sections running the length of the generator. The top and bottom sections 35, 36 are glass and nonconductive. The sides of the pipe 34 are actually electrical plates 37, 38 with electrical leads 39 attached. These plates are placed at right angles to the magnetic flow and expel and receive the electrons acted upon by the magnetic flow. This pipe does not touch anything inside the generator 17 and is surrounded by a vacuum to prevent the heat inside it from traveling to the other parts of the generator. The pipe is held in place by the outside container of the generator.
Generator magnets 40, 41 are placed above and below this center pipe 34 and are inside cryogen tanks 42, 43 which also support them. The magnets 40, 41 are super cooled by the cryogen in the tanks 42, 43. The purpose of cooling the magnets to a few degrees above absolute zero is to make them efficient and their produced magnetic field effective in relation to their size and weight. The cryogen surrounding the magnets could be either liquid oxygen or liquid nitrogen.
The cryogen tanks 42, 43 are sealed to the magnets 40, 41 and held in place relative to each other by supports 44, 45 attached to them. These supports must not only be strong enough to handle the weight of the magnets, 40, 41 cryogen, and tanks 42, 43 but also strong enough to handle the strong magnetic attraction between the magnets. The cryogen tanks 42, 43 with their respective magnets 40, 41 inside being held together with the supports 44, 45 then becomes a unit which is placed inside another tank 47.
This unit is held inside the tank 47 by supports 46 that are of a wedge in shape with the pointed side next to the unit. The purpose of the wedge and point is to expose the least amount of surface area between the cryogen tanks 42, 43 and the outer tank 47 to prevent flow of kinetic energy from the outer tank 47 to the cryogen tanks 42, 43. This flow of energy must be minimized to prevent the warming of the cryogen in the tanks 42, 43.
This insulating is also the purpose of the outer tank 47 and the inner vacuum that it holds. The vacuum inside this outside tank 47 keeps the cryogen tanks 42, 43 and magnets 40, 41 cold and prevents transfer of energy from the inside pipe 34 and the outside air to the magnets 40, 41
At the far end of the generator 17 is an electron emitter 48 which gives and directs electrons to the inside positively charged gas. These electrons come from the piston faces, dealt with later. This emitter 48 is so positioned to help pull the ionized gas through the generator 17 as well as help give a positive charge to the piston faces. The position is also important in this respect because of the relative low temperature of the ionized gas.
Referring to FIGS. 16, 17, 20 the electrons then pass by conductive circuit through a regulator 49 that fills a battery 50 where they next enter. The battery acts as a reservoir of electrons. The electrons then go to automobile auxiliary systems, such as starter, lights, radio, etc. (not shown) and also enter an engine control center 51. Here the electricity is distributed to the pistons 13 in the correct timing intervals described above, and in the correct initial amounts.
The correct volume of electricity or amperage varies with the load conditions placed on the engine no matter what the rpm. When the throttle is opened more fuel and air is injected into the engine to be burned and this produces more force, so the magnetic fields associated with the cylinders must be strengthened calling for a stronger current to the cylinder coils and piston units which establish these fields, which will be more fully described. This initial strength comes from the battery 50 but is soon replaced by the greater amounts and speed of the ionized exhaust. The varying amperage gives control to the burning process also under various conditions.
The main function of the control center 51 is the manipulation of the magnetic fields in the cylinders. The center varies the timing and strength of these fields to match the strength of the expanding gases in the combustion chamber. To explain the flow through the system it is best to start at the MHD generator 17 and end back at the generator.
The electricity comes from the generator 17 and goes either to the battery 50 through the voltage regulator 49 or to a throttle rheostat 52, whichever the greater need is at the moment. This flow stops and starts many times each second depending on engine rpm but only is in one and the same direction. It is a rapid staccato direct current of changing frequency and intensity. The flow then is channeled to a transistor 53 and a Silicon Controlled Rectifier (SCR) 54 that are governed by their respective pickup coils 55, 56. The pickup coils are wound about u-shaped arms 69 having sensing ends 70 thereon.
The voltages induced in coils 55, 56 are produced by magnets 57, 62 imbedded in a rotating disk 58 attached to the end of a rotary valve shaft 68 with matching rpm. The magnets 57, 62 rotate past the sensing ends 70 to induce the voltage. The transistor magnet 57 is 80 degrees long and activates its pickup coil 55 20 degrees before the pistons are fully together. This will be more fully described later. The last 20 degrees 71 of the transistor magnet 57 is tapered so that the current induced in the pickup coil 55 becomes gradually weaker until it stops altogether.
This current then regulates the flow of current allowed to pass through the transistor 53. When the transistor is turned on it activates a solenoid 59 which moves a rheostat 60 to its full "on" position. As the transistor 57 magnet in the disk 58 moves to the tapered end 71 the current in the coil 55 becomes less, the transistor 53 allows less current to pass through the solenoid 59 moving the rheostat 60 toward its "off" position. This rheostat 60 controls the amount of current going to the cylinders.
The solenoid 59 takes time to get from the full "off" position to the full "on", so to compensate for this time, it is activated before the pistons are ready to fire and thus the extra 20 degree length 131 on the transistor magnet 57 in the disk 58. Since the rheostat 60 then is turning "on" ahead of time and no electrons must pass between the piston electrodes during compression, a switch 61 is placed in the circuit. This switch is in the form of a relay 61.
This relay 61 is controlled indirectly by another magnet 62 imbedded in the disk 58. This magnet 62 is 60 degrees in length and is of constant width and magnetic strength. When current is induced in this magnet's pickup coil 56 it turns on its SCR 54 which allows current to travel from the battery 50 to the coil 63 in the relay 61. This closes the relay switch 72 allowing current, now under control by the solenoid controlled rheostat 60, to pass on toward the cylinders. Before, however, this current reaches the relay 61 and rheostat 60, it has passed through the throttle rheostat 52, controlled through the throttle linkage 64.
The purpose of throttle rheostat 52 is to govern the amount of current needed under the varying load needs of the engine, again to match magentic force and expanding gas in the cylinder. The more power demanded of the engine, the more current allowed to pass on through throttle rheostat 52.
Solenoids, rheostats, and relays are chosen because of the large amounts of current used. It is also possible to substitute variable capacitors for the rheostats if the interruptable direct current is the same in function as alternating current used in conjunction with capacitors. If not rheostats will work.
After leaving the second rheostat 60 the calibrated current travels to an induction coil 65 and to a cylinder coil 66. At the induction coil 65 the voltage of the current is greatly amplified and sent on to the pistons. The cylinder coil 66 does not need this voltage force because the current has a prearranged path through the coil. However, the current in the cylinder must have enough energy to knock off the electrons in the combustion gases and that is the reason for the induction coil 65.
Referring to FIGS. 18 and 19, a variable light control ignition can be used for generating the variable strength current to the SCR and transistor rather than the magnets on the disk and their pick up coils. Instead of the magnets 57, 62, a timing disk 158 has open slots 157, 162 of the same degree, width, length, position, and taper as the magnets 57, 62. Also instead of the pick up coils, 55, 56, the timing disk 158 has on one side a light source 155, 156 shining through the slots 157, 162. Actually four light sources are used. On the other side of the disk directly opposite each light source is a photo electric cell 159, 160. The light 155, 156 shines through the slot 157, 162 as the disk 158 turns and the cell generates current. As the taper 171 in the slot diminishes the light reaching the cell, the current produced becomes less and less. The light energy is directed by the shroud 161 surrounding the light bulb 162.
An advantage of this system is that no matter what the rpm of the engine the current produced by the cell 159, 160 remains relatively the same depending upon position of the slot 157, 162, provided the light source candle power remains constant. The current in the magnetic coil pick up would increase with greater rpm.
Referring additionally to FIGS. 11-15 and to FIG. 21, the current coming from the induction coil 65 passes through the electro-plate 75 and brush 76 of commutator 20, down the side of the piston arm 22 and the center post 78 in the piston face unit 102. After meeting the built in resistence 73 in the post and traveling through the magnet coil 74 the current passes to the piston electrodes 80, 82 and out through them into the combustion gases.
The electrodes 80 are placed around the piston face 81 to provide absolute magnetic coverage around the inner cylinder walls. The center electrode 82 is there to begin even ignition coverage as well as to present an overall magnetic field.
As the electrons then travel through the ionized combustion chamber gas and provide their magnetic field, they are prevented from straying to the cylinder walls by a nonconductive lining 25. This lining insulates the electrons from the engine and also acts as a reflector for the radiation produced by the burning process.
The cylinder lining 25 is made of glass. This material is chosen because it is hard, a nonconductor and can be readily worked to contain a cylinder coil 94. Its transparency allows the reflectiveness of the steel around it to repel the radiance of the fire in the chamber. Because of its hardness there are special break-in procedures that have to be used. The inside of the cylinders on a new engine are made with a fine roughness. The engine is then started with the cylinder coils 94 deactivated. This allows heat to build up in the chamber on the cylinder walls and the very tips of the roughness melt and form to the peculiarities of the piston rings thus seating them. The engine must then be turned off and the cylinder coils 94 connected.
The energized electrons fired into the gases, ignite the gases and free electrons from the molecule's atoms, giving the resulting ions a positive charge. At the same time, the piston magnet 79 has presented a positive charge to the piston face 81 repelling positive ions and attracting the free low energy electrons. The piston face 81 then scavenges the combustion gases of one electron per molecule even at the relatively low temperature which is the maximum allowed before nitrogen oxide formation. These electrons pass via piston face buss 99 on to the emitter 48 at the end of the MHD generator 17 and are really the electric fuel for this process.
This is an important function of this engine because without it the electrical processes would be inefficient. The current from the piston face 81 back to the generator tail emitter 48 is an important electric current in the engine. This current is rather hidden and subtle but is absolutely necessary, particularly because of the relatively low temperatures of the ionized gases.
The piston electromagnets 79 that do this scavenging have three functions. First, they must create a magnetic field with the positive side toward the combustion chamber. Second, they must emit or gather electrons through their electrodes 80, 82 shown imbedded in the magnetic core 83. Third, the electromagnets must gather electrons on their face 81 and act as an electron scrubber, gathering and removing electrons from the combustion gases at their relatively low temperatures. To do these functions the magnets have several components.
The piston face 81 is a conductor, of copper, and is separated from the piston by a dielectric 84 and has through it the electrodes 80, 82. There is more electrical resistance on this face 81 than between electrodes and its motivation is from a different source, the emitter 48, than that of the electrodes, the MHD generator 17. The face 81 is connected by a lead going through the magnet's core 83 to a ring contact 85 on the back of the unit. Ring contact 85 is insulated from the magnet core 83 by dielectric 109.
The electrodes 80, 82 and magnet's coil 74 are electrically connected through leads 86, 108 and a resistance 73 in the electrode post 78. This resistance 73 forces the electricity to travel through the coil 74.
This piston magnet unit has threads 87 on the outside and is screwed into the piston body 88 until it bottoms. At this point the face contact 85 and the coil contact 89 are pressed firmly against their corresponding contacts 90, 91 in the piston.
After passing through the combustion gases the current reaches the other piston electrodes 80, 82 and magnet 79, on through arm 22 via coil bus 98 commutator 20, and back to the generator 17. This then completes the circuit. As shown in the schematic there are several resistors 112, and diodes 113 placed in the system and these are to protect the various components against transient and incorrect voltages and to make sure the current is traveling in the right direction.
Referring to FIG. 21, the combustion ionized gases are contained by magnetic fields in two different longitudional configurations and piston end configuration working together for complete containment. The first configuration is the magnetic lines of force 92 created by the electron beams 93 as they pass through the gas in the chamber. This field circles the beam and as shown the number of beams around the outside of the cylinder creates a magnetic barrier around the cylinder. Secondly, the cylinder coil 94 circling magnetic lines of force 95 fill in the magnetic gaps that the beam lines 92 miss.
The piston lines of force come straight out from the piston. These prevent positively charge molecules from touching the piston surface as has been explained.
For emphasis the four main magnetic functions are now discussed. The first function is the MHD generator 17. This generator has two stationary magnets 40, 41 that are not electromagnets but are iron or steel. They pass magnetic lines of force through the moving ionized gas in the exhaust. The charged particles in the exhaust moving through the magnetic lines of force then produce the electric current used in the engine.
The second magnetic function is the piston magnet 79 use. It throws a positive magnetic charge toward the combustion chamber and then the lines of force bend around to the back of the piston completing the magnetic circuit. This positive force acts against the positive charge of the ions on the atoms of the gases in the chamber preventing them from touching the piston surface. This will attract electrons but their mass is so small compared to the atoms from which they originated it is of no moment or concern.
The third magnetic function is the magnetic field 92 surrounding electron beams 93 in the combustion chamber. This field's strength has upper and lower limits. It must be strong enough to prevent the ions from touching the cylinder lining and yet not so strong that it will compress the gas and increase its temperature above the 3200 degrees C. limit. The control center 51 regulates the amperage on the electron beam.
The fourth magnetic function is that provided by the cylinder lining coils 94. These fill in the gaps of the field 92 formed by the electron beams 93 and further insulate the cylinder walls 25. This magnetic field 95 is also timed and subject to variable strength which is controlled by the control center 51. | A magnetohydrodynamic generator feeds electrical energy to a six cycle internal combustion engine having pairs of opposed pistons in each cylinder and a three port rotary valve system. A first exhaust port leads the partially combusted gases from one cylinder to the next and a second exhaust port leads the ionized, fully combusted gases to the magnetohydrodynamic generator, where the ionized exhaust gases pass through cryogenic, super-cooled magnetic fields, towards an electron emitter at the output end of the magnetohydrodynamic generator.
The passage of the ionized gases through the magnetic fields produces current which is conducted to electrodes on opposed piston faces and to coils in the cylinder walls. The stream of electrodes between opposed piston faces and the coil in the cylinder sets up magnetic fields in the cylinders which isolate the combustion gases from the wall surface of the cylinder. The current produced in the magnetohydrodynamic generator is also conducted to a coil in the head of the piston which sets up a positive charge on the piston face which gathers electrons from the combusted gases in the cylinder and conducts them to the emitter in the magnetohydrodynamic generator.
Control of the magnetic fields is accomplished through a rotary disk having arc-shaped means of magnets or slots, which create electrical energy as they pass adjacent a sensing device of a coil sensor or a photo cell, respectively. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on 35 USC 371 application of PCT/DE 01/04338 filed on Nov. 17, 2001; and a continuation of U.S. Ser. No. 10/181,771.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to an injection nozzle for internal combustion engines, having a nozzle body, wherein the nozzle body has at least one first injection port and at least one second injection port, having a first nozzle needle, embodied as a hollow needle and guided in a guide bore of the nozzle body, having a second nozzle needle disposed coaxially to the first nozzle needle, wherein with the first nozzle needle, the injection of fuel through the at least one first injection port is controllable, and with the second nozzle needle the injection of fuel through the at least one second injection port is controllable.
[0004] 2. Description of the Prior Art
[0005] In the above injection nozzle, known from German Patent Disclosure DE 42 14 646 A1, the two nozzle needles are each triggered via a respective high-pressure fuel pump.
SUMMARY AND OBJECTS OF THE INVENTION
[0006] The object of the invention is to furnish an injection nozzle which is more variable with respect to injection course shaping and fuel atomization and which thus makes internal combustion engines possible that are more economical in fuel consumption, have lower emissions, and are quieter. Moreover, the injection nozzle of the invention should be economical to produce and should be usable without major modifications at the cylinder head of the engine. Finally, the injection systems equipped with the injection nozzles of the invention should also be more economical than known systems of the same variability.
[0007] This object is attained according to the invention by an injection nozzle for internal combustion engines, having a nozzle body, wherein the nozzle body has at least one first injection port and at least one second injection port, having a first nozzle needle, embodied as a hollow needle and guided in a guide bore of the nozzle body, having a second nozzle needle disposed coaxially to the first nozzle needle, wherein with the first nozzle needle, the injection of fuel through the at least one first injection port is controllable, and with the second nozzle needle the injection of fuel through the at least one second injection port is controllable, and wherein a pressure force in the closing direction of the second nozzle needle can be exerted on the second nozzle needle by a hydraulic fluid from a located in a control chamber.
[0008] In the injection nozzle of the invention, the at least one first injection port can be triggered in a simple way independently from the at least one second injection port. This creates the possibility of opening only the at least one first injection port at certain operating points of the engine upon injection, so that the fuel quantity to be injected can be injected into the combustion chamber through a relatively small injection port cross section. As a result,. first, smaller fuel injection quantities can be injected with greater precision, and second, the fuel injected into the combustion chamber through the at least one first injection port at high speed is better distributed, which has a favorable effect on the efficiency, emissions, and noise of the engine.
[0009] In an alternative mode of operation, the at least one second injection port can be opened immediately after the opening of the first injection port, or after a freely selectable time lag, so that a large quantity of fuel can be injected into the combustion chamber in the briefest possible time through the first and second injection ports. Because of the time lag between the opening of the first injection ports and the second injection ports, the injection course can be freely shaped over a wide range. This has advantages in terms of efficiency, the noise produced, and the emissions of the engine.
[0010] Moreover, for triggering the second nozzle needle, a second high-pressure fuel pump is not needed. Instead, a simple, economical pressure supply suffices, for instance from the oil pump of the engine. Furthermore, the second nozzle needle can be triggered more simply and precisely, since for opening the second nozzle needle, the pressure in the control chamber need merely be lowered.
[0011] Because the second nozzle needle is disposed inside the first nozzle needle, the injection nozzle of the invention takes up no more installation space than an injection nozzle of the prior art and accordingly makes do without miniaturized components, which has a favorable effect on both production costs and mass production.
[0012] In a variant of the invention, it is provided that a control chamber that can be subjected to a control pressure is present in the nozzle body, and that a second nozzle spring acting on the second nozzle needle and disposed in the control chamber is present, so that the second nozzle needle is pressed into its closing direction by the second nozzle spring, and the closing force, which is composed of the spring force of the second nozzle spring and the pressure force resulting from the control pressure in the control chamber, can be controlled within wide limits and with high chronological resolution by controlling the control pressure.
[0013] To make production and installation upon assembly of the injection nozzle of the invention simpler, the nozzle body is in multiple parts and has both an intermediate ring and a nozzle holder body, and/or a guide bush is provided in the guide bore; the guide bush can also serve as a stroke stop for the second nozzle needle. Using a guide bush is advantageous, for among other reasons, especially because the guide bush can be made of more wear-resistant material, and if the guide bush wears, only the guide bush has to be replaced, rather than the entire injector.
[0014] In a further embodiment of the invention, the intermediate ring acts as a stroke stop for the first nozzle needle, so that the stroke of the first nozzle needle can be set with great precision.
[0015] In another embodiment of the invention, a control piston is guided in the guide bush; the control piston defines the control chamber and transmits the pressure force, resulting from the control pressure in the control chamber, to the second nozzle needle, so that the area of the end face of the control piston can be selected independently of the diameter of the guide bore.
[0016] To simplify installation and calibration, it can be provided that the first nozzle spring is braced at least indirectly, for instance via an adjusting shim, via the guide bush or directly on the nozzle body ( 1 ). The guide bush can also serve as a stroke stop for the second nozzle needle, so that the stroke of the second nozzle needle is limited.
[0017] In a further feature of the invention, a pressure bolt is provided between the first nozzle spring and the first nozzle needle; the pressure bolt transmits the closing force of the first nozzle spring to the first nozzle needle, which makes for a compact, simple design.
[0018] If, as provided in a further advantageous feature of the invention, the pressure bolt serves as a stroke stop for the second nozzle needle, then the stroke stop for the second nozzle needle can be adjusted more precisely, since the axial spacing between the second sealing cone and the stroke stop is very short. Moreover, the second nozzle needle is closed simultaneously with the first nozzle needle, thus avoiding undesired after injections of fuel into the combustion chamber through the second injection ports.
[0019] It can additionally be provided that the pressure bolt is guided by the nozzle body, and in particular the intermediate ring of the nozzle body, and/or that the pressure bolt at least partly takes on the guidance of the second nozzle needle, thus further improving production, installation and function.
[0020] In another exemplary embodiment of the invention, the second nozzle needle is embodied in two parts, thus simplifying production and installation.
[0021] In another feature of the invention, the cross section of the at least one first injection port and the cross section of the at least one second injection port are equal in size, so that at all operating points, good atomization of the fuel in the combustion chamber is obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Further advantages and advantageous features of the invention can be learned from the description contained herein below, taken in conjunction with the drawings, in which:
[0023] FIG. 1 , a first exemplary embodiment of an injection nozzle of the invention;
[0024] FIG. 2 , an enlarged detail of FIG. 1 ; and
[0025] FIG. 3 , a second exemplary embodiment of an injection nozzle of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] FIG. 1 shows an exemplary embodiment of an injection nozzle of the invention in longitudinal section. The nozzle body 1 is adjoined by a shim 3 and a nozzle holder body 5 . The nozzle body 1 , shim 3 and nozzle holder body 5 can also be embodied in one piece. The multi-part embodiment shown in FIG. 1 , however, has advantages in terms of the production, installation and adjustment of the injection nozzle. The nozzle body 1 , shim 3 and nozzle holder body 5 are braced against one another by means of a union nut 6 . At the same time, the shim 3 is a stroke stop for the first nozzle needle 7 .
[0027] In the nozzle body 1 , a first nozzle needle 7 is guided in a guide bore 9 . The guide bore 9 continues in the shim 3 and nozzle holder body 5 as well and has changing diameters.
[0028] In the nozzle body 1 , a pressure chamber 11 is embodied, which is defined by a pressure shoulder 13 of the first nozzle needle 7 . Via a high-pressure inlet 15 , fuel from a high-pressure fuel pump, not shown, can be pumped into the pressure chamber 11 .
[0029] A first nozzle spring 17 , via a pressure bolt 18 , presses the first nozzle needle 17 into a first sealing seat 19 , shown only in suggested form in FIG. 1 , at the end of the nozzle body 1 .
[0030] In the closed state of the first nozzle needle 7 , a sealing cone 21 of the first nozzle needle 7 , in conjunction with the first sealing seat 19 , prevents fuel from the pressure chamber 11 from passing through a first injection port 23 into the combustion chamber, not shown in FIG. 1 , of an internal combustion engine, also not shown. The tip of the nozzle needle of the invention is shown in more detail in FIG. 2 and will be described in greater detail below in conjunction with that figure.
[0031] The mode of operation of the first nozzle needle is equivalent to that of a conventional injection nozzle. If the pressure force exerted on the pressure shoulder 13 by the fuel located in the pressure chamber 11 is greater than the closing force of the first nozzle spring 17 , the first nozzle needle 7 lifts from the first sealing seat 19 and thus uncovers the at least one first injection port 23 , and the injection begins. Fuel flows out of the pressure chamber 11 through an annular gap (not shown), formed by the guide bore 9 and the first nozzle needle 7 , in the direction of the first injection port 23 .
[0032] The first nozzle needle 7 has a central bore 25 , in which a second nozzle needle 27 is guided. The second nozzle needle 27 , in the exemplary embodiment shown in FIG. 1 , is embodied in two parts and comprises the portions 27 a and 27 b . The two-part embodiment of the second nozzle needle 27 is done for reasons of production and installation. In the region of the nozzle holder body 5 , a guide bush 29 is provided on the upper end of the guide bore 9 , and a control piston 31 is guided in the guide bush.
[0033] Between the control piston 31 and the end 33 of the guide bore 9 , a second nozzle spring 35 is disposed, which causes the control piston 31 to contact the second nozzle needle 27 . The end 33 of the guide bore 9 and the control piston 31 define a control chamber 37 , into which a control pressure inlet 39 discharges. The control chamber 37 is filled with a hydraulic fluid, whose pressure can be controlled via the control pressure inlet 39 . Fuel, motor oil, and other fluids can be used as the hydraulic fluid.
[0034] The pressure of the control chamber 37 filled with hydraulic fluid is exerted via the control piston 31 , in the same direction as the second nozzle spring 35 , on the second nozzle needle 27 and presses this nozzle needle into a second valve seat, not shown in FIG. 1 . By lowering the pressure in the control chamber 37 ; the closing force of the second nozzle needle 27 can be decreased to such an extent that the second nozzle needle 27 opens.
[0035] An underside 41 of the guide bush 29 , together with a shoulder 43 of the second nozzle needle, forms a stroke stop for the second nozzle needle 27 .
[0036] In the exemplary embodiment shown in FIG. 1 , the first nozzle spring 17 is braced against the nozzle holder body 5 via an adjusting shim 45 and the guide bush 29 . By changing the adjusting shim 45 , the prestressing of the first nozzle spring 17 can be adjusted in the simplest possible way and with high precision.
[0037] In FIG. 2 , the tip of an injection nozzle of the invention is shown enlarged. The first sealing cone 21 of the first nozzle needle 7 and its counterpart in the nozzle body 1 are designed such that linear contact results. This line of contact will be called the first sealing seat 19 and is shown as a dashed line in FIG. 2 . As FIG. 2 clearly shows, the first sealing seat 19 separates the fuel, which is at high pressure, in an annular gap 47 between the guide bore 9 and the first nozzle needle 7 from the first injection ports 23 , when the injection nozzle is closed. In the exemplary embodiment of FIG. 2 , two first injection ports 23 are shown, which face one another. However, it is also possible for injection nozzles of the invention to be equipped with a different number of first injection ports 23 or second injection ports 49 .
[0038] Somewhat farther toward the tip of the nozzle body 1 , two second injection ports 49 are shown. The second injection ports 49 are sealed off from a second sealing cone 51 and its counterpart in the nozzle body 1 . Once again, a linear area of contact results between the second sealing cone 51 and the nozzle body 1 , and this will hereinafter be called the second sealing seat 53 .
[0039] The mode of operation of the injection nozzle of the invention will now be described, referring back and forth to FIG. 1 and FIG. 2 .
[0040] When the high-pressure fuel system, not shown, which among other elements has a high-pressure fuel pump, pumps fuel at high pressure via the high-pressure inlet into the pressure chamber 11 , the first nozzle needle 7 lifts from the first sealing seat 19 , as soon as the pressure force, exerted on the pressure shoulder 13 by the fuel in the pressure chamber 11 , is greater than the closing force of the first nozzle spring 17 . Once the first nozzle needle 7 has lifted from the first sealing seat 19 , the fuel can flow out of the pressure chamber 11 via the annular gap 47 through the first injection ports 23 into the combustion chamber, not shown. At some operating points of the engine, not shown, the injection is optimal if the fuel is injected solely through the first injection ports 23 .
[0041] If the opening cross sections of the first injection ports 23 are inadequate to inject enough fuel into the combustion chambers within the available time, then the second nozzle needle 27 can be opened in addition. This is accomplished by lowering the pressure in the control chamber 37 . Since the second sealing seat 53 has a smaller diameter than the second nozzle needle 27 , the fuel that is at high pressure and is flowing out of the annular gap 47 toward the first injection ports 23 exerts a force counter to the closing force on an annular face 55 of the second nozzle needle 27 . The annular face 55 is defined by the second sealing seat 53 and the outer diameter of the second nozzle needle 27 . As soon as this force is greater than the closing force, the latter comprising the spring force of the second nozzle spring 35 and the pressure force of the hydraulic fluid located in the control chamber 37 , the second nozzle needle 27 lifts from the nozzle body 1 as well and thus uncovers the second injection ports 49 . In this state, large quantities of fuel can flow within a short time through the first injection ports 23 and second injection ports 49 into the combustion chamber, not shown.
[0042] If the pressure in the control chamber 37 is lowered with a time lag after the opening of the first nozzle needle 7 , an injection course can be shaped. In a first phase, when only the first nozzle needle 7 is opened, only little fuel flows through the first injection ports 23 . Upon the opening of the second nozzle needle, the quantity of fuel injected per unit of time increases sharply.
[0043] In FIG. 3 , a second exemplary embodiment of an injection nozzle of the invention is shown. Because of the agreement with the first exemplary embodiment in terms of components and function, the description of FIGS. 1 and 2 applies, and only the differences will be explained below.
[0044] In the exemplary embodiment of FIG. 3 , the second nozzle needle 27 is divided at the level of the pressure bolt 18 . The upper part 27 b of the second nozzle needle 27 , where it passes through the pressure bolt 18 , has a smaller diameter than the lower part 27 a of the second nozzle needle 27 . A central bore 57 in the pressure bolt, which bore guides the upper part 27 b of the second nozzle needle 27 , also has a smaller diameter than the lower part 27 a of the second nozzle needle 27 . The lower end 59 , in terms of FIG. 3 , of the pressure bolt 18 therefore forms a stroke stop for the nozzle needle 27 . Because of the shorter spacing, compared to the first exemplary embodiment, between the second sealing seat (see FIG. 2 ) and the stroke stop formed by the lower end 59 of the pressure bolt 18 , first, the stroke of the nozzle needle can be adjusted more precisely, and second, it is assured that the stroke of the second nozzle needle 27 is dependent on the stroke of the first nozzle needle 7 . The stroke of the second nozzle needle 27 can be greater, at maximum by the stroke play designated as 61 in FIG. 3 , than the stroke of the first nozzle needle 7 .
[0045] When the first nozzle needle 7 closes, the pressure bolt 18 , offset by the stroke play 61 , also closes the second nozzle needle 27 . This prevents after injections into the combustion chamber (not shown) from the second injection ports 49 (see FIG. 2 ).
[0046] It has proved advantageous if the total of the opening cross sections of the first injection ports 23 is approximately equal to the total of the opening cross sections of the second injection ports 49 .
[0047] The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments are possible within the spirit and scope of the invention, the latter being defined by the appended claims. | An injection nozzle for internal combustion engines is proposed, having a nozzle needle 7 and a second nozzle needle 27; the first nozzle needle 7 and the second nozzle needle 27 can be triggered independently of one another. The second injection nozzle is opened by lowering the pressure of a hydraulic fluid in a control chamber 37. By this means, the injection quantity per unit of time and the atomization of the fuel in the combustion chamber can be varied over wide ranges, and moreover a shaping of the injection course can be performed. | 5 |
[0001] The present invention relates to the field of turbomachines. It relates to the damping of a blade made of a composite material and its object is more particularly the damping of a fan blade in a turbojet engine or else a propeller airfoil in a turboprop engine.
BACKGROUND OF THE INVENTION
[0002] The blades, notably of a fan, but also of a low-pressure compressor, made of composite material with carbon fibers are made in different ways. According to one manufacturing method, a stack of one-way plies or preimpregnated wovens is produced that is placed in a mold while orienting the successive plies differently before compacting and polymerization in an autoclave. According to another method, woven preforms of dry fibers are prepared that are assembled by sewing or else a single preform made of woven fibers in three dimensions, that is impregnated with resin by injection in a closed mold. The blade is formed in a single piece comprising the root with the airfoil. It comprises various protections in order to reinforce the thermomechanical resistance thereof. A metallic protection is therefore attached to the leading edge or to the whole contour of the airfoil comprising the leading edge, the blade tip and the trailing edge, for example in the form of a titanium part bonded over the whole surface of the leading edge and over a front portion of the outer surfaces of the extrados wall by mounting a protective film that can be made of a synthetic material, polyurethane for example, and directly bonded to the intermediate part.
[0003] The object of the invention is this type of blade with at least one protection along the leading edge. An example of manufacture is described in patent EP1777063 in the name of the present applicant.
[0004] The object of the invention is more generally any type of blade made of composite material, the airfoil of which is formed of fibers, threads or filaments, optionally woven, impregnated with a heat-curable resin.
[0005] Flutter is a phenomenon of coupling between the aerodynamic and elastic characteristics of the blade creating unstable situations. A flutter manifests itself asynchronously. Subsonic flutter is distinct from supersonic flutter. The fan blade is mainly concerned by subsonic flutter.
[0006] Flutter is a phenomenon that is difficult to predict, because of the complexity of the coupling between the aerodynamic and mechanical responses. Moreover, the mechanical damping of the blade is usually not very well known. Finally, in the current design of increasingly loaded blading, flutter is a phenomenon that must be particularly taken into account.
[0007] During the design of the fan blade, a margin of flutter is estimated, which measures, at a given flow rate, the difference between the line of flutter and the line of operation. This value is usually established based on a known reference (the closest) by adding thereto the differences calculated between this reference configuration and the new configuration. The criteria used nowadays for subsonic flutter on 1 F and 1 T modes and on zero diameter coupled mode are:
Twist Bend Coupling (TBC), representing the ratio between the movements in twisting mode and in bending mode. The higher the TBC parameter, the greater the risk of flutter also. The reduced speed or Strouhal criterion given by the following formula:
VR=W/C*f*pi, where W is the relative speed, C the chord of the blade at a given height and f the frequency of the blade mode in question. This criterion represents the coherence between the vibrational frequency of the blading and the frequency of the unsteadiness of the flow along this blading.
[0010] Other factors may influence the flutter margin and may occasionally be used when the phenomenon is encountered during tests: reduction of the specific flow rate, reduction of the number of blades or increase in the chord, lubrication of the blade root, detuning.
[0011] The object of the invention is to improve the harmonic response of the blade to synchronous aerodynamic excitations such as:
inlet duct distortions generated by flying conditions in angle of incidence—climbs, descents, crosswinds, the harmonic excitations generated by a residual imbalance, backpressure fluctuations, induced by a fixed impeller of the stator type on a fan impeller, wake or backpressure fluctuations induced by a moving fan impeller on its neighbor in the case of an architecture with two contrarotating rotors.
DESCRIPTION OF THE PRIOR ART
[0016] A damping technology has been studied for several years by the present applicant with a first evaluation on one-piece bladed disks. The latter terms designate a disk-and-blade assembly manufactured in a single piece. The operating principle of the damping system is based on the dissipation of energy through the shearing of a suitably placed viscoelastic material. The correct behavior of the damping system is dependent on the dimensions of the material and on good adhesion between the material and the engine part.
[0017] Also known is U.S. Pat. No. 6,471,484 which describes a system for damping vibrations in a gas turbine engine rotor comprising a single-piece bladed disk. The airfoils of the blades are provided with a cavity hollowed in an intrados face or extrados face and containing a layer of damping material with a stress layer. A covering sheet covers the cavity. In operation, the damping of the vibrations is promoted by the shearing stresses induced in the damping material between the airfoil and the stress layer on the one hand and in the damping material situated between the stress layer and the covering sheet on the other hand. Patent application EP926312 describes a similar damping device applied to a fan blade of a turbojet engine.
SUMMARY OF THE INVENTION
[0018] The object of the present invention is an improvement to this technique in an application to a blade made of composite material with, in particular, optimization of the location of the damping treatment.
[0019] According to the invention, the turbomachine blade made of composite material, such as a fan blade of a turbojet engine or a propeller airfoil of a turboprop engine, comprising an airfoil formed of filaments or fibers, optionally woven, impregnated with a heat-curable resin, with an intrados wall and an extrados wall between the leading edge and the trailing edge, is characterized in that a device for damping the vibrations is incorporated in at least one of the intrados and extrados walls, and is formed of at least one layer made of viscoelastic material and a layer made of rigid material, these layers being superposed, the layer made of rigid material comprises a first zone and a second zone, the layer made of viscoelastic material being interposed between the airfoil and said first zone of the rigid layer, and said second zone of the rigid layer being attached to the wall of the airfoil without interposition of viscoelastic material and the rigid layer comprises said first zone and said second zone, and is arranged so that the first zone of the rigid layer comprises at least two lobes, the two lobes being attached to the second zone.
[0020] According to one embodiment, the layer made of viscoelastic material is attached, by the vulcanization of a film of viscoelastic material, by bonding by means of an adhesive material or by a mechanical connection such as by bolting or screwing, to the rigid layer on one side and to the airfoil on the other side.
[0021] The thickness of the viscoelastic layer is advantageously situated between 0.1 mm and 1 mm. The layer of rigid material, for its part, preferably has a thickness of between 0.5 mm and 1 mm.
[0022] For this other embodiment, the second zone, by which the rigid layer is secured to the airfoil, is preferably situated radially on the side of the root of the blade relative to the first zone. More particularly, the second zone of the rigid layer is bonded to the airfoil. Optionally the rigid layer may be held and immobilized along this second zone by mechanical means.
[0023] The functions of the viscoelastic layer are to introduce a mechanical damping for the vibratory responses of the blade, in particular in the case of a fan blade for the bending mode 1 F and twisting mode 1 T, and also to play a damping role during phenomena such as during a bird strike, by absorbing a fraction of the impact energy and thus limiting the damage to the blade. The damping device is applied in the zones that are subjected to high deformation energy levels of the vibratory mode to be damped. The zones in which the levels are at a maximum are particularly sought.
[0024] According to another objective of the invention, there has been an attempt to optimize the shape of the device in order to obtain the best possible damping. It has therefore been determined that the shearing stresses were at a maximum in the peripheral zone of the rigid layer. The invention therefore proposes to form the rigid layer so that its contour is as long as possible taking account of the surface covered by the device.
[0025] The rigid layer comprises at least two lobes. The shape of the lobes may be varied. The lobes may advantageously have an elongated shape and extend in a radial direction relative to the root of the blade. Therefore the shape may be comb-like, star-like or another shape. According to another particular embodiment, an overall contour of increased length is created by arranging cuts along closed, for example circular, lines in the rigid layer.
[0026] According to another embodiment, the layer of viscoelastic material is contained at least partially in a cavity arranged in the composite material of the airfoil.
[0027] The viscoelastic material is chosen from materials such as rubber, silicone, polymer elastomer or epoxy resin. It may have a single layer or many layers and the layers may if necessary be formed of different materials, depending on the environment, the materials used and the damping characteristics sought. For example, the damping characteristics may differ to cover more extensive temperature ranges.
[0028] The rigid layer is metallic or else made of the same material, based on filaments, as the airfoil. “Filaments” also means threads and fibers. To the extent that the rigid layer has sufficient rigidity in the direction of the deformations of the airfoil, the layer may be thin and not disrupt its aerodynamism.
[0029] According to another embodiment, at least one additional layer made of rigid material is interposed at least partly between the rigid layer and the airfoil, with two layers of viscoelastic material placed on either side of the additional layer, the viscoelastic layers being formed of different or identical materials.
[0030] Preferably the layer of viscoelastic material is secured to the rigid layer and/or to the airfoil by vulcanization of a film of viscoelastic material or else by bonding by means of an adhesive material. The layers may also be secured to one another by a mechanical connection means, such as bolting or screwing.
[0031] According to a particular application, the leading edge of the airfoil comprises a protective coating formed of a metal strip bonded to the airfoil on at least a portion of its surface.
[0032] In the latter case, advantageously a layer of viscoelastic material is interposed at least partly between the metal strip and the airfoil so as to form a second vibration-damping device.
[0033] According to a variant, said metal strip is rigidly connected to the rigid layer of the damping device applied to the intrados or extrados wall.
[0034] Finally, the invention relates to a method for producing a damping device on a blade according to which the shape of the lobes of the first zone of the rigid layer is determined so as to have a contour of the rigid layer that is as high as possible taking account of its surface area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] A nonlimiting embodiment of the invention will now be described in greater detail with reference to the appended drawings in which:
[0036] FIG. 1 represents schematically a turbojet engine with a front fan.
[0037] FIG. 2 shows a fan blade made of composite material with a protective element protecting the leading edge having zones comprising a viscoelastic damper.
[0038] FIG. 3 shows, in a top view of the blade of FIG. 2 , the region of the leading edge of the blade.
[0039] FIG. 4 shows a schematic view in perspective of a blade comprising a vibration-damping device according to the invention.
[0040] FIG. 5 shows a schematic view in perspective of a blade comprising a vibration-damping device according to a variant embodiment of the invention.
[0041] FIG. 6 shows an arrangement of the damping device of the invention.
[0042] FIG. 7 shows another arrangement of the damping device of the invention.
[0043] FIG. 8 shows another arrangement of the damping device of the invention.
[0044] FIG. 9 shows a schematic view in perspective of a blade comprising a variant of a vibration-damping device according to the invention.
[0045] FIG. 10 is a graph showing the damping properties of a device comprising a combination of viscoelastic materials, over a range of temperatures.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] With reference to FIG. 1 , shown schematically is an example of a turbo-machine in the form of a twin-spool bypass turbojet engine 1 . A fan 2 at the front supplies the engine with air. The air compressed by the fan is divided into two concentric flows F 1 and F 2 . The secondary flow F 2 is discharged directly into the atmosphere and provides an essential portion of the motive thrust. The primary flow F 1 is guided through several compression stages 3 to the combustion chamber 4 where it is mixed with the fuel and burned. The hot gases supply the various turbine stages 5 which drive the fan 2 and the compression rotors 3 . The gases are then discharged into the atmosphere.
[0047] FIGS. 2 and 3 show a fan blade 10 capable of being used on this type of engine. It is a blade made of composite material. In general, the airfoil 10 A, made of composite material, of the blade consists of fibers or filaments linked together by a heat-curable resin. The filaments or fibers are made of carbon or another material such as glass, silica, silicon carbide, alumina, aramid or an aromatic polyamide. The filaments are, according to a known method of assembly, in the form of woven elements. The leading edge is in this instance coated with a metallic protective means 10 B. It is, for example, a titanium foil bonded by the layer 30 to the composite material extending along the leading edge, with a strip forming a wing on each side: one wing 10 Bi on the intrados wall downstream of the leading edge and one wing 10 Be on the extrados wall downstream of the leading edge. The two wings are connected along the leading edge by a thicker portion 10 B 2 .
[0048] Such a blade is manufactured for example according to the technique described in patent EP 1,777,063 in the name of the present applicant.
[0049] According to the latter technique, a preform is constructed by weaving filaments in three dimensions. The one-piece woven preform is then trimmed to shape by cutting the contour according to a three-dimensional graphic. The part is placed in a forming mold. Then, after appropriate deformation, the part is placed in a compacting mold which stiffens the deformed preform. The leading edge is overcompacted so as to allow the placement of the protective element along the leading edge. This is an element in the form of a longitudinal half-sleeve with two wings designed to cover a portion of the extrados wall and intrados wall downstream of the leading edge. As explained in the patent cited above, the protective element is placed in a mounting device capable of parting the wings. The protective element is placed, via its leading edge pre-coated with adhesive, between the two wings and then the latter are released.
[0050] The assembly is placed in an injection mold into which a binder comprising a heat-curable resin is injected so as to impregnate the whole preform. Finally the mold is heated to the curing temperature of the resin. It is then sufficient to remove the part from the mold.
[0051] In patent application FR 0706430 dated Sep. 13, 2007 in the name of the present applicant, a description is given of the production of a vibration-damping means by incorporating, between one of the intrados or extrados walls of the airfoil and the protective element 10 B, at least one layer of a viscoelastic material, located for example in one of the zones 11 , 12 or 13 . The metal protective element 10 B forms a rigid backing layer for the vibration-damping system that it forms with the layer of viscoelastic material.
[0052] According to the invention, a damping device is placed on the intrados wall and/or the extrados wall. In FIG. 4 , which represents schematically a blade provided with a damping device, the damping is achieved on the extrados wall of the airfoil 100 A. In this instance, this airfoil comprises a protective element 100 B fitted to the leading edge. The airfoil is obtained as in the airfoil of application FR 0706430 reported above based on filaments or fibers impregnated with a heat-curable resin.
[0053] The damping device comprises a viscoelastic layer 111 interposed between the wall 100 A, intrados or extrados, of the airfoil and a rigid layer 110 .
[0054] Viscoelasticity is a property of a solid or a liquid which, when it is deformed, exhibits a behavior that is both viscous and elastic by simultaneous dissipation and storage of mechanical energy.
[0055] A rigid material in the vibration-damping system is more rigid than the viscoelastic material of the layer. In other words, the isotropic or anisotropic characteristics of elasticity of the material of the backing layer are greater than the isotropic or anisotropic characteristics of the viscoelastic material in the desired thermal and frequency operating range. The material of the viscoelastic layer is of the rubber, silicone, polymer elastomer, epoxy resin or thermoplastic material type.
[0056] The embodiment shown in FIG. 4 illustrates a device covering approximately ⅓ of the intrados surface area and/or extrados surface area of the blade. This ratio of one third of the intrados or extrados surface area to which the device is applied preferably corresponds more generally to the extent of the device of the invention.
[0057] The arrangement of the damping device can be seen in FIG. 6 which shows a partial section of the blade in the direction A-A in FIG. 4 . The rigid layer 110 is attached by means of a rigid attachment means 112 directly to the wall 100 A of the airfoil. The attachment means is advantageously a layer of adhesive material. However, a mechanical means is equally suitable.
[0058] In this embodiment, the rigid layer comprises two zones: a first zone 110 1 and a second zone 110 2 . The attachment means 112 extends along the second zone 110 2 . A viscoelastic material 111 is interposed between the wall 100 A of the airfoil and the first zone 110 1 to which this material is attached.
[0059] Preferably the second zone 110 2 by which the rigid layer is attached to the blade is on the side of the blade root relative to the first zone. Depending on the bending or twisting deformation, the rigid layer moves relative to the blade wall and the viscoelastic layer opposes by resisting the movement. The result of this is an action of damping against the vibrations sustained by the blade. The device is preferably placed on the portions of the blade sustaining maximum deformation for the mode in question.
[0060] The solution of the invention makes it possible to produce a thin device. The rigid layer, the thickness of which is between 0.5 and 1 mm, is formed so as not to affect the air flow along the airfoil and the aerodynamic properties of the latter. If necessary, the airfoil is slightly hollowed in order to contain the damping device so that its outer profile is in the continuity of the blade wall.
[0061] The invention is not limited to this embodiment, the layer made of rigid material is, according to one embodiment, attached to the airfoil by means of the viscoelastic layer which adheres or is bonded both to the layer of rigid material and to the airfoil.
[0062] According to a variant illustrated by FIG. 7 , the damping device comprises an additional rigid layer 117 between the rigid covering layer 110 and the wall 100 A. The additional rigid layer 117 is held between two layers of viscoelastic material: one layer 111 between the two rigid layers 117 and 110 , one layer 115 between the wall 110 A and the additional rigid layer 117 . The rigid layers may be formed of the same material or of different materials. The same applies to the two viscoelastic layers 111 and 115 which may be made of different materials depending on the environment and the damping sought.
[0063] The additional layer 117 is not attached to the wall; it is preferably free to move to the extent that the deformation of the viscoelastic material allows. The viscoelastic layer is secured to the layers and walls that are in contact with it by vulcanization, to the extent of the possibilities offered by the material. It can also be bonded as can be seen in FIG. 8 . The layer 111 is bonded by means of a film of an appropriate adhesive substance, 118 and 119 respectively, to the rigid layer 110 and to the wall 100 A.
[0064] The embodiments of FIGS. 7 and 8 show the attachment 112 of the rigid layer to the wall.
[0065] However, the invention also includes the embodiment in which the connection of the rigid layer to the airfoil is obtained only by means of the viscoelastic and rigid intermediate layers.
[0066] FIG. 5 shows a variant damping device on a blade 200 combining the damping achieved by the rigid layer 210 on the wall, in this instance the intrados, of the airfoil and the damping achieved by the protective layer 200 B of the leading edge of the airfoil associated with a viscoelastic layer. According to this combination, the two layers 200 B and 210 are secured in a coupling zone 210 B at the tangency between the two plates forming the layers.
[0067] The coupling zone 210 B between the rigid layer 210 and the leading edge may have a greater or lesser extent. Nevertheless, preferably, the aim is to minimize it in order to prevent a phenomenon of mechanical locking of shearing on the damper of the airfoil wall. Specifically, the larger the coupling zone, the less the vibration energy is dissipated.
[0068] It should be noted that the coupling zone 210 b , although formed of rigid material, allows relative movement between the rigid layer 210 and the protective layer 200 B.
[0069] In this case, the two layers 210 and 200 B are cut from one and the same material.
[0070] In the embodiment with two zones of the rigid layer, the viscoelastic layer is placed in a first zone between the two rigid layers and the airfoil. A second zone of this assembly can be rigidly attached to the airfoil.
[0071] FIG. 9 shows a variant of the invention. On the basis of an observation that the damping is more effective at the border of the rigid layer, the rigid layer is formed so as to maximize the extent of this border. According to the nonlimiting example illustrated by FIG. 9 , the first zone beneath which the viscoelastic layer is interposed is in the form of lobes or in this instance of fingers 310 1 ; these lobes preferably extend radially relative to the root 300 C of the blade, substantially parallel to the plate 300 B protecting the leading edge. The lobes are connected to the second zone 310 2 of the rigid layer 310 which is rigidly attached to the wall 300 A of the blade. To the extent that the gradients of movement between the rigid layer and the application surface are at a maximum on the edges of the device, a structure with lobes allows an effective damping by shearing of the viscoelastic layer. Shearing is zero in the middle of the rigid layer because of the symmetry of the bending movement and is at the maximum on the edges where the gradient of movement between the rigid backing layer and the supporting structure is at the maximum.
[0072] In FIG. 10 , the curves show the value there would be in combining several viscoelastic materials when it is a matter of being operational over a relatively extensive temperature range. Each material exhibits a peak for a given temperature. Here there are three materials, the effectiveness ranges of which cover distinct temperature ranges. By combining the three materials, the effectiveness of the damping device is extended over a temperature range covering the three temperatures T 1 , T 2 and T 3 .
[0073] The materials are placed in layers side by side on the airfoil and/or superposed. | The present invention relates to a blade made of composite material ( 100 ) comprising an airfoil ( 100 A) formed of filaments or fibers, optionally woven, impregnated with a heat-curable resin, with an intrados wall and an extrados wall between the leading edge and the trailing edge.
It is characterized in that a device for damping the vibrations is incorporated in one or other of the intrados and extrados walls, and is formed of at least one layer made of viscoelastic material ( 111 ) and a layer made of rigid material ( 110 ), these layers being superposed. According to one embodiment, the layer made of rigid material comprises a first zone ( 110 1 ) and a second zone ( 110 2 ), the layer made of viscoelastic material ( 111 ) being interposed between the airfoil and said first zone ( 110 1 ) of the rigid layer ( 110 ), and said second zone ( 110 2 ) of the rigid layer being attached to the wall of the airfoil ( 100 A) without interposition of viscoelastic material.
The invention relates in particular to a turbomachine blade, such as a fan blade of a turbojet engine or a propeller airfoil of a turboprop engine. | 5 |
BACKGROUND OF THE INVENTION
[0001] The invention relates to an apparatus for decanting pulverulent product into a receptacle made of deformable material—in particular into a bag—which receptacle or bag is arranged in a container made of rigid material and is temporarily placed upstream of a lock system containing so-called glove boxes, according to the preamble of Patent Claim 1 . The invention moreover relates to a method which can be carried out using said apparatus.
[0002] Various systems are known which can be used to empty toxic powder out of drums equipped with plastic bags, in such a way that there is little contamination. One of the most common methods is the use of isolation systems. The drum is introduced into the isolator through a lock, lifted by a mechanical device, and then the plastic bag filled with the product is opened by an operator using gloves. The product is then emptied manually into a funnel which is connected to the lower part of the isolator. The disadvantage of these isolation systems is that they are designed for specific applications and therefore have only a very small degree of flexibility. The space requirement and investment costs of such systems are considerable. Moreover, a considerable amount of dust is produced within the isolator, so that the filters rapidly become blocked, the system has to be cleaned frequently and there is a risk that product will be lost.
[0003] There is also a system which contains a transparent cylindrical glove box, as it is known, with side openings for gloves. A stainless steel ring with a flat seal is fixed to the lower part of the glove box and provides a seal with respect to the drum. A movable suction lance is introduced from above, which suction lance is connected to the glove box through a sealing sleeve. The system is connected to a pneumatic lifting device which allows the glove box to be raised and lowered above the drum. The drum is emptied by an operator with the aid of the suction lance, which is connected to a pneumatic conveyor system. The powder is conveyed under vacuum and emptied in a completely closed manner into the containers which are to be filled.
[0004] Compared to a conventional isolator, the advantages of such a system are a small space requirement and reduced investment costs. Depending on the type of product, however, the use of the suction lance may prove to be taxing and time-consuming. Moreover, it is sometimes difficult to completely empty the plastic bag. Furthermore, the system cannot be used for products which contain lumps. When emptying a large number of drums (>10 drums), the emptying time for a unit of product may prove to be very long and unsatisfactory (10-15 min/drum).
[0005] In view of this, the inventor set himself the aim of eliminating the recognized problems. In particular, it is to be possible for drums equipped with plastic bags which contain toxic powder to be emptied virtually without any contamination (<1 μg/m 3 ) and in a semi-automatic manner.
SUMMARY OF THE INVENTION
[0006] The object is achieved according to the invention, wherein a rotatable shaft is mounted—preferably on at least two side stands which are arranged at a lateral distance from one another and form a main frame—at a distance from an adjustable base, on which shaft at least one hood designed as a glove box—or a hood trough or a hood system—is fixed. Moreover, at least one support plate as a holding base for the rigid container is attached to length-adjustable piston/cylinder units at an adjustable distance from the shaft, said support plate being parallel to the shaft longitudinal axis; the rigid container is designed such that it can be sealingly connected at the other end to a connecting tube which projects into the hood, the hood trough or the hood system.
[0007] According to a further feature of the invention, the hood or the hood trough—or the outer region of the hood system—is formed of metallic material, preferably of stainless steel, and is provided at least in the part remote from the base with a window element; gloves or glove-like devices are provided in openings at a front region, into which gloves or glove-like devices an operator can insert his hands in order to open the inner bags of the drums or receptacles without any contamination.
[0008] It has proven advantageous to connect the rigid container or the drum to the hood or hood trough or hood system by pneumatic pistons which are fitted at the side. These pistons seal the system by pressing the drum against the adjacent lower plate of the apparatus which is provided with a seal.
[0009] According to another feature of the invention, the hood or hood trough or hood system is fitted in a receiving compartment of the shaft, from which the above-mentioned piston/cylinder units for the support plate project.
[0010] This system is installed on a so-called main frame which has a pair of—more or less radial—end walls of the receiving compartment which are close to the shaft mountings on side stands for the shaft and from which axis-parallel longitudinal walls project in each case; two longitudinal walls which are aligned with one another are designed as connection elements for the piston/cylinder units.
[0011] It has proven advantageous to fix the hood or hood trough to the longitudinal walls of the receiving compartment which are remote from the piston/cylinder units. Moreover, the hood or hood trough should extend through at least one axis-parallel plate which is passed through by the connecting tube.
[0012] According to a further feature of the invention, a tension frame is assigned to the connecting tube, by means of which tension frame a pressing pressure can be generated on the outer face of the tube wall, by virtue of which pressure the free end of the bag can be fixed to the connecting tube. To this end, a pressure ring of the tension frame should be placed against the tube wall, which pressure ring is designed to be displaceable in a radial and/or axis-parallel direction; this pressure ring is preferably provided as a flexible and inflatable profile. The pressure ring is advantageously held by at least one sliding foot which guides it, which sliding foot surrounds an axis-parallel tension arm of the tension frame and can be displaced on said tension arm in an axis-parallel manner and fixed at a desired location.
[0013] Advantageously, the mouth region of the receptacle made of deformable material—that is to say of the bag—can be fixed between the tension frame and the connecting tube. Said receptacle for receiving the pulverulent product should be arranged as an inner bag within an outer bag which surrounds it as a cover; both bags are located in the aforementioned rigid container, that is to say the drum of the apparatus. The mouth region of the covering or outer bag is preferably fixed on an annular fixing device which surrounds an opening—assigned to the rigid container or drum—of the hood or hood trough or hood system. Said fixing device is a profile ring which surrounds the opening, wherein the outer face of said profile ring is assigned at least one pressure profile as a clamping element for the mouth region of the outer bag. A foot web should be integrally formed towards the outside of the profile ring as a support for a pressure profile.
[0014] According to the invention, the connecting tube is connected to a pneumatic conveyor system by means of a connecting element, wherein the connecting element preferably tapers away from the connecting tube in a funnel-like manner. Moreover, the connecting element should be equipped with a device which breaks up agglomerations or lumps which may be present in the pulverulent product, for example a grinding mechanism.
[0015] It is particularly important that the apparatus is equipped with a manual or automatic tilting device, by means of which the system can be tilted by 180°. The upper part of the system can—depending on the application—be equipped with various connections. The system consists in any case of a connecting tube with an inflatable seal, against which the inner bag is to be fixed.
[0016] In order to prevent the inner bag from falling down when the drum is tilted and thus hindering complete emptying of the drum, certain steps must be taken when fixing the bag. The previously opened inner bag is firstly fixed by means of an O-ring to a ring welded to the bag holder. The upper part of the bag is then fixed to the connecting tube, which is installed at the top in the system with an inflatable seal. Since the space between the bag and the drum is closed, the bag is usually held back during the emptying operation. It is also possible to place this space under slight negative pressure in order to ensure that the bag is securely held.
[0017] In one embodiment of the invention, a processing unit which can rotate with the shaft is arranged on the latter, from which processing unit the connecting tube extends in the radial direction with respect to the shaft; one compartment half of the processing unit which holds said connecting tube is assigned to the receiving compartment of the apparatus and the other compartment half is provided with a closable filling element. To this end, it is particularly advantageous for there to be at least one compartment half which in terms of its cross section tapers away from the shaft; a closure member should be arranged between the connecting tube and the compartment half which tapers towards the connecting tube.
[0018] A common bushing which surrounds the shaft adjoins the compartment halves on either side, wherein a radial panel element for connection to the receiving compartment is fixed to the bushing. In particular, a motor is connected to the shaft of this apparatus.
[0019] The scope of the invention also encompasses a connecting funnel which is connected by a hose to a pneumatic conveyor system and is fixed to the connecting tube in the upper part of the hood. Once the drum has been connected to the system, it is tilted and automatically emptied by the conveyor system. In the case of products which do not flow very well, a back-and-forth movement may be applied in order to break possible powder bridges. Advantageously, the lower plate of the hood may be made of a porous material in order to replace the filter of the suction funnel.
[0020] The scope of the invention also encompasses a method for decanting pulverulent product into a receptacle made of deformable material, in which the bag which receives the product is placed in another bag and is arranged together with the latter in the rigid container, whereupon the rigid container is sealingly connected to a hood designed as a glove box or to a hood trough or to a hood system and the mouth region of the open inner bag is connected to a connecting tube. The product is fed to a reactor or else is fed to another inner bag in a metered manner.
[0021] The system according to the invention can therefore be used to fill and empty for example rotating processing units—biconical dryers, mixers or the like—in a closed manner. The hood is continuously connected to the processing unit. A drum filled with raw material is attached to the system and loaded into the apparatus by the force of gravity once it has been tilted by 180°. At the end of processing—which comprises drying and mixing operations, the powder is loaded into a new drum.
[0022] The system according to the invention can also be used as a dispensing unit; in the pharmaceutical industry, it is often customary to decant a container containing raw material into smaller, precise loads.
[0023] It is also possible to meter a precise amount of powder from one drum into a second drum by placing two hood systems on weighing scales, said hood systems being separated by a metering valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Further advantages, features and details of the invention will emerge from the following description of preferred examples of embodiments and with reference to the drawing. In the drawing:
[0025] FIGS. 1, 2 , 4 , 6 to 8 , 10 to 14 : show a device in different operating positions with a drum or container for receiving bags;
[0026] FIGS. 3, 5 show an enlarged detail from FIG. 2 at the arrow III therein and from FIG. 4 at the arrow V therein, respectively;
[0027] FIGS. 9, 15 show an enlarged detail from FIG. 8 and FIG. 10 at the arrow IX therein and from FIG. 14 at the arrow XV therein, respectively;
[0028] FIG. 16 shows a partially cut-away diagram of a holding apparatus for the device as shown in FIGS. 1 to 15 for actuation thereof;
[0029] FIG. 17 shows a partial section through
[0030] FIG. 16 in the radial plane R therein;
[0031] FIG. 18 shows an enlarged detail from FIG. 16 ;
[0032] FIG. 19 shows the holding apparatus of FIG. 16 in a different operating position and with a connected reactor, in side view;
[0033] FIGS. 20, 21 , 23 show in each case a side view of different embodiments of the holding apparatus;
[0034] FIG. 22 shows an enlarged detail from FIG. 21 ;
[0035] FIGS. 24 to 37 show in each case a diagram, corresponding to the diagram in FIG. 16 , of the apparatus at different steps in the method, wherein a symbolic method diagram above each of the figures is assigned to each of said figures;
[0036] FIG. 38 shows a schematic diagram of a displaceable holding apparatus;
[0037] FIG. 39 shows the cross section through FIG. 38 in the radial plane R thereof.
DETAILED DESCRIPTION
[0038] A drum-like container 10 of diameter d and height h is placed with its baseplate 14 —integrally formed on a container wall 12 —on a grate 16 . A hood 22 of height h 1 which is made of stainless steel and has a glass window (not visible in the drawing) in the upper region is arranged on a vertical tube 34 of diameter c above the upwardly pointing mouth opening 18 of the drum or container 10 , coaxial to the vertical axis A thereof, it being possible for said hood to be lowered onto said vertical tube in the closure direction z.
[0039] Following the lowering operation, an annular circumferential edge 24 of the hood 22 which is graduated downwards and inwards in cross section bears with its lower sealing portion 25 on the upper edge 19 of the container wall 12 which surrounds the mouth opening 18 , as shown in FIG. 4 . The drum or container 10 is connected to the hood 22 by pneumatic pistons which are fitted at the sides of the system. These pistons seal the system by pressing the drum 10 against the circumferential edge 24 of the system—which as already mentioned is provided with a seal. A waste bag 27 can be seen here above the circumferential edge 24 , which waste bag receives the below-described tension faces 54 , 48 following removal thereof. Not shown in FIG. 4 are two gloves 26 which are both attached to the front side of the hood 22 in openings. Two filters 32 of the “push-through” type are also provided opposite the gloves 26 ( FIG. 17 ).
[0040] It can be seen in particular from FIGS. 3, 5 that a profile ring 28 of angular cross section and of height i projects downwards from the circumferential edge 24 , wherein the outer side of said profile ring—which ends in an integrally formed, outwardly directed foot web 29 —has a tension belt 30 lying opposite it at a radial distance a.
[0041] Above its mouth edge 36 , the vertical tube 34 is assigned a tension frame 38 , the design of which is shown particularly clearly in FIG. 9 ; a pressure profile 42 projects from an axis-parallel tension arm 40 thereof—which is arranged at a central distance b from the wall 35 of the vertical tube 34 on a radial bar 39 —towards the vertical tube 34 , which pressure profile can be moved in an axis-parallel manner by virtue of a sliding foot 43 which surrounds the tension arm 40 by actuating an adjustment handle 41 —and can be guided against the vertical tube 34 by the—possibly inflatable—sealing member designed as a pressure ring 44 made of elastic material.
[0042] Shown within the interior space 20 of the drum or container 10 is a bag 46 which is arranged about the vertical axis A, the upper mouth region 47 of which bag is connected to said profile ring 28 of the hood 22 by a round profile 31 in the open state shown in FIGS. 2, 4 , 6 to 12 and the interior space 48 of which bag receives an inner bag 50 for pulverulent product Q. When the hood 22 is located as shown in FIGS. 1, 2 at a distance from the upper edge 19 of the container 10 , a hood opening 23 delimited by the tension frame 28 is closed by a tension face 54 , which tension face is in turn pressed against the outer face of the profile ring 28 by an O-ring or round profile 31 , as shown in FIG. 3 . This tension face 54 may be formed for example by a portion of the mouth region 47 of the previously handled—and then cut—outer bag 46 , and may be clamped by a central clamp 56 .
[0043] By virtue of the two gloves 26 attached to the hood front, the inner bag 50 in the closed drum or container 10 can be opened from outside by an operator without any risk and its mouth region 51 can be fed to the pressure ring 44 . As shown in FIGS. 6 to 10 , once the sliding foot 43 on the tension arm 40 has been raised in the direction of the arrow x, the mouth region 51 of the inner bag 50 is pressed against the outer face of the wall 35 of the vertical tube 34 by the above-mentioned pressure ring 44 , and said vertical tube 34 is thus connected to the bag space 52 . Once the latter has been filled by introducing the pulverulent product Q, its mouth region 51 is removed and closed by a clamp 56 as shown in FIG. 10 ; it then serves as a tension face 58 for closing the vertical tube 34 . A further clamp 56 a closes the remaining inner bag 50 . The latter is pressed into the container interior 20 . Shown in FIG. 14 is the abovementioned flat profile or tension belt 30 which is released in order to move the O-ring 31 downwards.
[0044] By virtue of a rotary device 60 as a main frame which is shown in FIGS. 16, 18 , the inner bag 50 is rapidly emptied in a simple manner. This rotary device 60 has, at a clear distance e from one another, two side stands 62 which are fixed to an adjustable base B and are each provided with a shaft mount 63 , between which a rotatable receiving compartment 66 is located on a shaft 64 , the longitudinal axis N of which shaft runs at a distance n from the adjustable base B; said receiving compartment has, on two radial end walls 67 , in each case two shaft-parallel longitudinal walls 68 and contains a hood trough 80 in which the connecting tube 34 a engages from above in FIG. 16 . Within the compartment-like hood trough 80 , a transverse plate 84 which is made of window glass and is parallel to the longitudinal axis N of the shaft 64 is fixed on axis-parallel shoulders 81 of the side wall 82 , said transverse plate being passed through by the connecting tube 34 a . The latter is surrounded by a tension frame 38 a which is made in one piece with the glass or transverse plate 84 and has essentially been described above. A transverse arm 45 projects at right angles from the free end of the axis-parallel tension arm 40 a of said tension frame, wherein the pressure ring 44 is mounted in the channel-like pressure profile 42 of said transverse arm and in FIG. 18 presses the mouth region 51 of the inner bag 50 against the tube wall 35 . This inner bag 50 passes through the hood opening 23 —which in this case is located in a baseplate 87 parallel to two ridge profiles 86 of the hood trough 80 —which surrounds the profile ring 28 . The mouth region 47 of the outer bag 46 is fixed to the foot web 29 of said profile ring. Above the baseplate 87 screwed to the side wall 82 , the profile ring 28 is continued by an add-on ring 85 which has clamping elements 85 a for the inner bag 50 on its outer circumference.
[0045] At its other end, the connecting tube 34 a opens into a connecting funnel 70 , from which a joining tube 71 having a closure mechanism and filter 72 projects radially. Installed on the connecting funnel 70 , which is connected by a hose to a pneumatic conveyor system, is a filter which makes it possible to draw out the conveyed air of the powder. Optionally, a lid 75 of the funnel 70 may be designed as a plate made of a porous material, in order to replace the filter of the suction funnel.
[0046] Axis-parallel piston/cylinder units 76 project from the radial longitudinal walls 67 of the receiving compartment 66 towards the base in FIG. 16 , which piston/cylinder units are connected at the other end to a support plate 78 , the clear shaft distance n 1 of which is adjustable. In the starting position, this support plate 78 is seated with adjustable feet 79 on the aforementioned adjustable base B and serves as a support face for the drum or container 10 . The bags 46 , 50 thereof are connected to the hood trough 22 a in the above-described manner, so that the bag space 52 adjoins the connecting tube 34 a . In the cross section shown in FIG. 17 , a filter for the powder is clearly shown at 33 ; said filter is connected to the upper part of the connecting funnel 70 (not visible in the drawing).
[0047] The previously opened inner bag 50 is firstly fixed on a ring welded to the bag holder with the aid of the round profile or O-ring 31 . The upper part of the inner bag 50 is then fixed to the vertical or connecting tube 34 a , which is installed in the ridge region of the system by means of an inflatable seal. By actuating the piston/cylinder units 76 and shortening them, the space between the inner bag 50 and the drum 10 is closed for the emptying operation. It is also possible to place this space under slight negative pressure in order to ensure that the inner bag 50 is securely held.
[0048] Once the shaft 64 has been rotated through 180° by actuating a handwheel 65 with a drive member 65 a connected downstream towards the shaft 64 , the joining tube 71 of the connecting funnel 70 is connected by a conveyor hose 88 to a reactor unit 90 and specifically to a lateral shoulder connection piece 96 of a cylindrical tube 94 made of electrolytically polished stainless steel which projects from a reactor 92 and the interior 95 of which serves as a pumping chamber; this is connected to the conveyor hose 88 which serves as a supply line—conveying direction y. Said shoulder connection piece contains a so-called butterfly valve 89 as a closure member in a connection flange for the conveyor hose 88 .
[0049] Shown above the lid 93 of the reactor 92 are a valve housing 98 and a drive element 99 for a butterfly valve. Towards the top, the cylindrical tube 94 ends at a filter insert 100 which is covered by a domed lid 104 provided axially with a T-shaped connection tube 102 . Said domed lid is fixed by a locking device to coupling hooks of the cylindrical tube 94 . Extending from the connection tube 102 is firstly a vacuum line 106 with vacuum valve 107 for a vacuum pump arranged upstream thereof, and secondly a conveying gas line 108 for a conveying gas source, said conveying gas line having a closure valve 109 .
[0050] During a suction phase, the butterfly valve 89 of the supply line 88 opens and the discharge line remains closed. By virtue of a vacuum being built up via the vacuum line 106 , the pumping chamber 95 then fills up to a desired filling level, or possibly completely.
[0051] After a predetermined period of time, the supply line 88 is closed and the discharge line is opened. Once the closure valve 109 in the conveying gas line 108 is opened, the powder Q is out under the action of pressure—for example by nitrogen for filter cleaning purposes. At the end of the suction phase, the vacuum line 108 remains open for a certain time before the butterfly valve of the discharge line is opened, in order to remove the oxygen from the pumping chamber 95 .
[0052] Of particular importance during this operation is the filter in the filter insert 100 , which holds back the powder and at the same time provides the suction capacity of the system. By virtue of its position between the pumping chamber 95 and the conveying gas source, the filter is cleaned during each cycle and thus maintains its full filtration capacity.
[0053] The closure elements 89 , 107 , 109 and the butterfly valve of the discharge line are connected to one another in terms of control technology at a control box. During a suction phase, the butterfly valve 89 of the supply line 88 opens whereas the discharge line remains closed. By virtue of the vacuum valve 107 which is open during this, the pumping chamber 95 sucks in powder until it is full; after a predetermined period of time, the supply line 88 closes and the discharge line is opened. The conveyed product is pushed out under the action of pressure—compressed air or nitrogen for filter cleaning purposes. The filter in the upper part of the cylindrical tube 94 holds back the very fine particles and is cleaned during each emptying cycle.
[0054] Prior to introducing the powder into the downstream reactor 92 , air and powder are separated from one another by the closure of the vacuum shut-off valve 107 being delayed with respect to the opening of the conveyed product inlet. In order that no gases from the reactor 92 can be sucked in when the discharge line is opened, the cylindrical tube 94 is firstly placed under pressure and only then is the emptying valve opened. Moreover, the vacuum line 106 can be opened only when the discharge line is closed.
[0055] The drum 10 which is connected to the hood trough 80 and tilted is automatically emptied by the conveyor system. In the case of products which do not flow very well, a back-and-forth movement may be applied in order to break possible powder bridges.
[0056] If the product Q to be emptied contains lumps, a lump-breaking system shown at 74 in FIG. 20 may be integrated in the suction or connecting funnel 70 . In this embodiment, the side walls 82 a are of rectangular cross section and—like the side walls 82 of FIGS. 16 , 19 —are connected to the longitudinal walls 68 and the ridge plate 86 by screws 69 .
[0057] The system according to the invention can also be used to fill and empty for example rotating processing units 100 —biconical dryers, mixers or the like—in a closed manner. In FIG. 21 , the hood system 80 a lying in the vertical axis A of the apparatus 61 is permanently connected to the processing unit 110 and is loaded into the apparatus 61 by the force of gravity, once it has been tilted by 180°. At the end of the processing method—drying, mixing—the powder is loaded into a new drum 10 . The shaft 64 of the apparatus 110 of overall height f of in this case 2200 mm and a length g of approximately 2500 mm is driven by a motor M which is fitted outside the side stands 62 ; between the latter, the shaft 64 passes through said processing unit 110 which contains two compartment halves 112 , 112 t —each tapering away from the shaft 64 —which are adjoined on either side by the bushings 113 which surround the shaft 64 . A radial panel element 114 for a receiving compartment 66 a to which the hood system 80 a is connected is fixed to each of said bushings.
[0058] The upper compartment part 112 has a closable filling connection piece 111 . The connecting tube 34 a extends from the lower compartment part 112 t —with the interposition of a closure element 116 —in the vertical axis A and passes through a tension frame 38 in this case, too.
[0059] The system according to the invention can also be used as a dispensing unit. In the pharmaceutical industry, it is often customary to decant a drum containing raw material into smaller, precise loads. Using the apparatus 120 shown in FIG. 23 , it is possible to meter a precise amount of powder Q from one drum 10 to a second drum 10 a by connecting two hood systems 80 b —which are at an axial distance q from one another and are separated by a metering valve 122 —to weighing scales. These weighing elements—assigned to the two hood systems 80 b —bear the reference 124 in FIG. 23 .
[0060] FIGS. 24 to 37 show fourteen steps of the method; the diagrams which can be seen in each case above the apparatus 120 are intended to illustrate the individual steps, for example the insertion of two bags 46 , 50 into a drum 10 in the first step ( FIG. 24 ). The fixing of the mouth region 47 of the outer covering bag 46 to the profile ring 28 in the second step is shown in FIG. 25 , and then FIG. 26 shows the shortening of the piston/cylinder units 76 —and the lifting of the drum 10 —in the third step. The removal of the tension face 54 , the opening of the inner bag 50 and the clamped fixing of the mouth region 51 thereof by means of the pressure ring 44 can be seen in FIGS. 27 to 29 , and the rotation of the shaft 64 —together with the lowering of the support plate 78 which is now close to the base onto the adjustable base B—is shown in FIG. 30 . The insertion of a drum 10 containing two bags into the support plate 78 close to the base can be seen in FIG. 31 , and the opening of the bag 46 , 50 as a ninth step can be seen in FIG. 32 . The metering of the powder Q within the top inner bag 50 with partial transfer to the bottom inner bag 50 is shown in FIG. 33 , and closure of said inner bag is shown in FIG. 34 . The steps of closing the outer covering bag 46 and separating it from the tension face 58 remaining on the profile ring 28 then follow. Finally, FIG. 37 shows the closing of the drum 10 containing the metered amount of powder.
[0061] FIGS. 38, 39 show that a system 128 according to the invention can be used to empty not just drums 10 but also a so-called big bag 130 with a glued-in double liner. In this case, a filling funnel 70 a which is open towards the base is arranged in a movable support frame 134 having travelling rollers 123 . Extending from the filling funnel 70 a is a joining tube 71 a for a conveying line 88 , which leads for example to the reactor 92 shown in FIG. 18 . At the upper funnel edge 73 there is a filter 136 for the conveying. The mouth edge 140 of the big bag 130 is seated on an inflatable seal 138 , this being surrounded by a horizontal glass plate 84 a ; the latter engages over the hood system 80 a .
[0062] A conveying rail 142 for a carriage 144 with a suspension device 146 for the simplified transport of the big bag 130 which can be suspended thereon can be seen above the movable support frame 134 .
[0063] The cross section of FIG. 39 shows, on the hood system 80 a , a filter 32 , two pairs of gloves 26 and a waste opening 148 . | An apparatus for decanting pulverulent product (Q) into a receptacle ( 50 ) made of deformable material which receptacle is arranged in a container made of rigid material and is temporarily placed upstream of a lock system containing so-called glove boxes, a shaft ( 64 ) is rotatably mounted at a distance (n) from an adjustable base (B), on which shaft at least one hood designed as a glove box, at least one hood trough ( 80 ) made of metallic material, preferably of stainless steel, is fixed; at least one support plate ( 78 ) for the rigid container is attached to length-adjustable piston/cylinder units ( 76 ) at an adjustable distance from the shaft ( 64 ), the support plate being parallel to the shaft longitudinal axis (N), and the rigid container is sealingly connected at the other end to a connecting tube ( 34 a ) which projects into the hood or the hood trough ( 80 ) or the hood system. | 1 |
This application is a continuation-in-part of our copending application having Ser. No. 23,912, filed Mar. 26, 1979, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a new class of polyols. More particularly, the invention relates to chain-extending existing polyols with epihalohydrin in the presence of a base or alkali metal thereby forming an extended polyol with at least one internal hydroxyl group attached directly to the backbone chain.
2. Description of the Prior Art
It is well known to react polyisocyanates with polyols and, e.g., water, to form flexible polyurethane foams. For the most part, the polyols used in these reactions are triols comprising three backbone chains emanating from a central starter molecule such as glycerol or trimethylol propane and the like. These three chains are relatively uniform in structure and in chain length, each averaging about 1,000 to about 2,000 units of molecular weight. Such molecules can be viewed as comprising a long linear chain having a near centrally attached long chain branch, each leg of which bears a terminal --OH group, for example, ##STR1## U.S. Pat. No. 3,322,698 discloses rigid cellular urethanes prepared by reacting in the presence of a blowing agent, an organic polyisocyanate and a polyether derived from the reaction of an epihalohydrin and at least one polyol of the formula:
HOCH.sub.2 --(CHOH).sub.n --CH.sub.2 OH
wherein n is 1 to 4. The polyether forming reaction is carried out in the presence of an acidic fluorine-containing catalyst, e.g., fluoboric acid, to obtain a polyether containing the group
--CH--(CH.sub.2 X)--CH.sub.2 O--
wherein X is fluorine, chlorine or bromine.
U.S. Pat. No. 3,222,300 relates to forming cellular polyurethanes obtained by reacting an organic polyisocyanate with modified polyalkylene ether glycols. The polyalkylene ether glycols bearing solely terminal hydroxyl groups are formed by reacting at least one mole of epoxide or glycidyl ether with a mole of polyalkylene ether glycol.
The polyols of the instant invention have internal hydroxyl groups attached directly to the backbone and no halide present.
DESCRIPTION OF THE INVENTION
The instant invention is directed to a process of forming a chain-extended polyol composition containing at least three OH groups of the general formula: ##STR2##
at least one of R 1 and R 2 is H and the other is independently selected from the group consisting of H, CH 3 and phenyl; R 3 is H, CH 3 , CH 2 CH 3 or --OCH 2 --; n is 0 or 2; x is 1-3; z is 1-10 and a and b are independently selected from 1 to 1000, which comprises reacting at a temperature in the range 50° to 120° C., preferably 90°-110° C. an epihalohydrin, a base and polyol independently selected from the formula:
(H--A.sub.a).sub.x --B--A.sub.b H
wherein the members A, B, a, b and x are as hereinbefore set forth, said epihalohydrin, base and polyol being present in a molar ratio of 1.0:0.9 to 1.2:1.1 to 4.0 respectively, removing the thus formed salt and thereafter recovering the thus formed chain-extended polyol.
Thus, by the practice of the instant invention, chain-extended polyols of varying lengths can be obtained depending upon the molar ratio of the starting polyol or polyols to the epihalohydrin. For example, when the molar ratio of polyol (P) to epihalohydrin (E) is substantially 2:1, the chain-extended polyol will have the general formula:
(P)-(E)-(P)
If the molar ratio is 3:2, the chain-extended polyol will theoretically have the general formula:
(P)-(E)-(P)-(E)-(P)
Additionally, it is possible to employ different polyols as reactants in the practice of this invention. That is one may use a polyol having substantially ethylene oxide units (PEO) in its backbone in combination with a polyol having substantially propylene oxide units (PPO) in its backbone. If the molar ratio of (PEO) to (PPO) to E is substantially 1:1:1, then the resultant chain-extended polyol will have the general formula:
(PPO)-(E)-(PEO)
Also, operable as starting materials are polyols which are, within themselves, a combination of different units such as a hydrophilic polyol containing at least 40 mole percent ethylene oxide units with the remaining 60 mole percent being another alkylene oxide such as propylene oxide.
The epihalohydrins used in the instant invention are of the formula: ##STR3## wherein X is fluorine, bromine or preferably chlorine. Such materials are commercially available. The epihalohydrin is used herein in an amount necessary to chain-extend the existing polyols in the presence of substantially a stoichiometric amount of base to react with the halide present in the epihalohydrin. The base used herein is preferably NaOH, but other well known alkaline bases, e.g., KOH, sodium methoxide, etc., are operable herein. In some instances it is preferred but not necessary to dissolve the base in an aqueous medium such as water prior to or during the mixing with the existing polyol for homogeneity of admixture. The water is then removed by conventional means prior to addition of the epihalohydrin to form sodium alkoxide. That is, the equilibrium of the reaction:
NaOH+ROH→NaOR+H.sub.2 O↑
wherein R is the remaining moiety of a polyol, is shifted to the right by removing water from the system. Any remaining hydroxide ion or water could hydrate the epihalohydrin or reaction intermediates to undesired products. Volatile alcohols in equilibrium with alkoxide salts are removed in the same manner.
Sodium or other alkali metals, which for the purpose of this invention are considered as bases herein, can also be used to convert the polyol directly to alkoxide with the evolution of hydrogen, thusly
2Na+2ROH→2NaOR+H.sub.2 ↑
The existing polyols to be chain-extended by the practice of this invention can be formed in various ways to obtain diverse hydroxyl terminated materials. One method of forming a polyol is to add either singly or plurally, stepwise or random one or more alkylene oxides to a polyalcohol to produce a hydroxyl-terminated, polyether-containing polyol. Alkylene oxides operable for forming said existing polyols include, but are not limited to, ethylene oxide, propylene oxide, butylene oxide, styrene oxide and mixtures thereof. Polyalcohols reacted therewith to form the existing polyols include, but are not limited to, ethylene glycol, diethylene glycol, 1,4-butanediol, propylene glycol, glycerine, triethanolamine, dipropylene glycol, cyclohexane dimethanol, erythritol, sorbitol, sucrose, trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol, tetrakis (hydroxyethyl) ethylenediamine, tetrakis (hydroxypropyl) ethylene diamine and mixtures thereof. Primary amines and polyamines such as n-butylamine, n-dodecylamine, ethylenediamine, propylenediamine and the like may also be used.
Another method of forming the existing polyols chain-extended in the instant invention is to react polybasic acids with polyalcohols with the concomitant splitting out of water during the ensuing esterification reaction. Polyalcohols used in this method essentially are the same as were enumerated above. Polybasic acids used in this method include, but are not limited to, adipic acid, maleic acid, succinic acid, oxalic acid, malonic acid, dimer acid, phthalic acid, trimellitic acid, pyromellitic acid and mixtures thereof. Also operable as polybasic acids are the corresponding anhydrides and acyl halides thereof.
The molar ratio of the epihalohydrin, base and polyol reactants is in the range 1.0:0.9 to 1.2:1.1 to 4.0 respectively, preferably 1.0:1.0:1.5 to 2.0.
The reaction can be carried out at pressures ranging from atmospheric to 50 psi, preferably at substantially atmospheric pressure at temperatures ranging from 50-120, preferably 90°-110° C. The reaction can be performed under atmospheric conditions, i.e., in air, but preferably the reaction is performed in the absence of oxygen under an inert blanket, e.g., nitrogen, to avoid oxidation of the existing or resultant chain-extended polyols.
The precipitated salt is removed by filtration, centrifugation or other conventional means. The product can then be treated with conventional ion exchange resins or clays having ion exchange capability to reduce soluble metal ions to an acceptable level. An organic solvent, e.g., acetone, toluene, ethyl acetate, may be added to facilitate filtration or treatment with ion exchange resin and is later stripped from the product.
In all examples of making the chain-extended polyol herein a round bottom flask equipped with heating mantle, stirrer, thermometer, gas inlet, gas outlet, vacuum line, addition funnel, distillation head with condensor, receiver and cold traps as needed was used.
The general preferred procedure of forming the chain-extended polyols is as follows. The polyol (z+1 moles) is melted, if necessary, weighed and charged to a reactor. The exact weight needed is calculated from the hydroxyl analysis of the polyol corrected for water content (K. Fisher analysis). Standardized aqueous base ((0.9 to 1.2) z moles) is added and all possible water is distilled from the starting material at 100°-110° C., 1 to 5 Torr in 1-2 hours. The vacuum is cut off and the reactor brought to atmospheric pressure with nitrogen. The epihalohydrin (z moles) is weighed and added to the polyol at 50°-120° C., pref. 90°-110° C. in 1-2 hours. Heating is continued until no more salt precipitates or the pH of a sample dissolved in water reaches a minimum value. Any excess epihalohydrin is stripped from the reaction product.
Salt is separated from the product by filtration or centrifugation. Solvent, exemplified by, but not limited to, toluene, acetone, ethyl acetate or chlorinated hydrocarbons can be added to lower the viscosity of the slurry to facilitate the separation. The salt is washed with solvent. The product solution is passed through a column of ion exchange resin or a clay with ion exchange capability to remove traces of alkali metal ion that would be undesirable if the polyol is to be used in making polyurethane products.
The following examples are set out to explain, but expressly not limit, the instant invention. Unless otherwise noted, all parts and percentages are by weight.
EXAMPLE 1
Preparation of Triol
Two kilograms (2 moles of commercially available polyethylene glycol MWt. 1000) containing 1.00 mole of sodium hydroxide in 150 ml of water was heated to 110° C. at 20 Torr with good stirring to remove all the water. To the resultant brown liquid, at 90° C., was added over a period of 45 minutes, 95 g (1.025 moles) of epichlorohydrin. The resultant liquid slurry containing a precipitate of sodium chloride was stirred for 2 hours at 90° C. The product had a pH of 7.0 as measured with moist, pHydrion® paper. To the product slurry was added 250 ml of water and the resultant mixture heated to 100° C. Saturated NaCl- brine solution separated from the product and was removed by decantation. The process was repeated again with 200 ml H 2 O. The organic product liquid was stripped of water at 100° C. and 20 Torr with good stirring. The amber liquid was then filtered free of residual salt. The resultant product of the formula: ##STR4## wherein 23 represents the average number of monomer units per poly(ethylene oxide) block, analyzed as follows:
0.3% H 2 O (K. Fischer), 0.33 meq OH/g
1.86 meq OH/g (acetic anhydride end group titration)
1.53 meq OH/g (corr. for H 2 O), theory is 1.45
EXAMPLE 2
Preparation of Triol
To four kilograms of commercially available polyethylene glycol (MWt. 1000) were added 2.00 moles of sodium hydroxide in 300 ml of water. The water was removed from the resultant solution by heating to 100°-110° C. at 10 Torr for 1.5 hours with good stirring.
To the above dried liquid at 90° C. was added 190 g (2.05 moles) of epichlorohydrin over a period of 45 minutes. The reaction was stirred at 90° C. for 3 hours whereupon the pH (moist pHydrion® paper) was 7.0. 500 ml of water were added to the reaction mixture and stirred for 20 minutes at 100° C. The pH of the resulting brine phase was 6.0-6.5. Water was removed from the liquid product at 100°-110° C. and 10 Torr with good stirring for 2 hours. The resultant precipitate of sodium chloride crystals was allowed to settle out at 50° C. for several days and the liquid product was separated by decantation.
______________________________________Analyses:meq OH/g (via acetylation) = 1.73H.sub.2 O (Karl Fischer) = 0.2% (0.22 meq OH/g)1.72-0.22 = 1.51 (theory 1.45)______________________________________
EXAMPLE 3
Preparation of a Triol
To 1200 g (2 moles) of commercially available polyethylene glycol (MWt. 600) were added 1.02 mole of sodium hydroxide in 150 ml of H 2 O. The water was then removed by heating at 110° C. and 20 Torr for 1.5 hours. To the resultant liquid at 100° C. and atmospheric pressure was added 97 g (1.05 m) of epichlorohydrin over a period of 45 minutes. The reaction was stirred for 2 hours. The pH of the product was 7.0 (moist pHydrion® paper) and contained a precipitate of sodium chloride. To aid in filtration of the precipitate the product slurry was diluted with 1.5 liters of methyl ethyl ketone. The filtrate was stripped of methyl ethyl ketone at 50°-90° C. at 20 Torr for several hours. The resultant polyol product of the general formula: ##STR5## on analysis by n.m.r. showed 3.05 meq. OH/g (theory 2.4) of hydroxyl.
EXAMPLE 4
Preparation of a Triol
In a 2 liter, 3 neck flask with a heating mantle, stirrer, thermometer and distillation head was mixed 900 g (1.5 mole) polyethylene glycol 600 MW and 1 mole of KOH in water. Most of the water distilled off as it was heated to 100° C. under vacuum. Most remaining water was stripped by heating the residue at 100° to 100° at 1 to 5 Torr for one hour. Epichlorohydrin, 83 g, 0.9 mole was added dropwise from a dropping funnel over one hour. Potassium chloride started to precipitate soon after the addition was started and the exothermic reaction raised the temperature from 100° to 110° C. The temperature was kept in this range for 2 hours after the addition was complete. The product was stripped but little or no epichlorohydrin remained.
The slurry was diluted with an equal volume of methanol and stirred overnight with about 10 g of decolorizing charcoal. The solution was filtered and separated into two fractions. One was passed through a column of Amberlyst 15 ion exchange resin (acid form). The other was passed through a column of Dowex 50WX8 ion exchange resin. When the solvent was stripped from both samples, salt precipitated from them indating that alcohols are not useful solvents for this purpose. They were redissolved in acetone, filtered and passed through acid regenerated ion exchange resins. The acetone was stripped. The first sample contained 2.38 to 2.43 milliequivalents of hydroxyl per gram (420 to 412 equivalent weight) and 0.01% water. The second contained 2.40 to 2.43 meq OH and 0.02% water. This product corresponds to triol (theory 2.39 milliequivalents of hydroxyl per gram).
The chain extended polyols of the instant invention can be capped with a polyisocyanate. Polyisocyanates operable herein to form prepolymers for making foams or hydrogels are of the formula R--(NCO) n wherein n is 2-4 and R is a polyvalent organic moiety having the valence of n. The polyisocyanate is reacted with the claim-extended polyol of the present invention in an amount ranging from stoichiometric up to a 20% excess per equivalent OH in the polyol. The prepolymer forming reaction is carried out at a temperature in the range 20°-100° C. preferably 30°-60° C. Although the reaction is operable under atmospheric conditions, it is preferably carried out in an inert, moisture free medium, e.g., under a nitrogen blanket. Suitable polyisocyanates useful in preparing this type of prepolymer include toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, commercial mixtures of toluene-2,4- and 2,6-diisocyanates, ethylene diisocyanate, ethylidene diisocyanate, propylene-1,2-diisocyanatecyclohexylene-1,2-diisocyanate, cyclohexylene-1,4-diisocyanate, m-phenylene diisocyanate, 3,3'-diphenyl-4,4'-biphenylene diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,5-naphthalenediisocyanate, cumene-2,4-diisocyanate, 4-methoxy-1,3-phenylenediisocyanate, 4-chloro-1,3-phenylenediisocyanate, 4-bromo-1,3-phenlenediisocyanate, 4-ethoxy-1,3-phenylenediisocyanate, 2,4'-diisocyanatodiphenylether, 5,6-dimethyl-1,3-phenylenediisocyanate, 2,4-dimethyl-1,3-phenylenediisocyanate, 4,4'-diisocyanatodiphenylether, benzidinediisocyanate, 4,6-dimethyl-1,3-phenylenediisocyanate, 9,10-anthracenediisocyanate, 4,4'-diisocyanatodibenzyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, 2,6-dimethyl-4,4'-diisocyanatodiphenyl, 2,4-diisocyanatostilibene, 3,3'-dimethyl-4,4'-diisocyanatodiphenyl, 3,3'-dimethoxy-4,4'-diisocyanatodiphenyl, 4,4'-methylene bis(diphenylisocyanate), 4,4'-methylene bis(dicyclohexylisocyanate), 1,4-anthracenediisocyanate, 2,5-fluorenediisocyanate, 1,8-naphthalenediisocyanate and 2,6-diisocyanatobenzfuran.
Also suitable are aliphatic polyisocyanates such as the triisocyanate Desmodur N-100 sold by Mobay which is a biuret adduct of hexamethylenediisocyanate; the diisocyanate Hylene W sold by du Pont, which is 4,4'-dicyclohexylmethane diisocyanate; the diisocyanate IPDI or Isophorone Diisocyanate sold by Thorson Chemical Corp., which is 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate; or the diisocyanate THMDI sold by Verba-Chemie, which is a mixture of 2,2,4- and 2,4,4-isomers of trimethyl hexamethylene diisocyanate. Another technique to produce the prepolymer is to use a polyfunctional isocyanate having a functionality greater than 2 in combination with the chain-extended polyol. Suitable polyisocyanates useful in this technique include PAPI (a polyaryl polyisocyanate commercial product sold by the Upjohn Company as defined in U.S. Pat. No. 2,683,730), 2,4,6-toluene-triisocyanate and 4,4'4"-triphenylmethane triisocyanate.
The following examples show the making of an isocyanate capped prepolymer and a foam therefrom.
EXAMPLE 5
Preparation of Triisocyanate from the Triol
One kilogram of the triol from Example 1 (1.53 eq OH) was heated to 100°-110° C. at 15 Torr for one hour to remove any traces of water. The liquid was then cooled to 55° C. at one atm. and 2 g of benzoyl chloride were added to neutralize traces of sodium alkoxides which might induce unwanted condensations of isocyanates.
To the above liquid was added 353 g (2.04 m) of toluene diisocyanate (80/20 2,4-2,6 isomer mix). A slight exotherm occurred and the reaction was stirred at 60°-65° C. for 45 minutes. The reactants then stood at 25° C. for 16 hours to give an amber liquid, viscosity 7000 cps at 25° C., having an isocyanate content of 1.72 meq/g (theory 1.88 meq NCO/g) of the formula: ##STR6## The resultant foam was very resilient.
EXAMPLE 6
Preparation of a Foam
To 80 g of an aqueous solution containing 2.0% Pluronic L-62 (a surfactant, commercially available from BASF-Wyandotte) in a quart cup was added 80 g of the isocyanate-capped, chain-extended polyol from Example 5. The mixture was stirred vigorously for 15 seconds and then allowed to foam. | The invention disclosed is for novel polyols and a method of making said polyols which comprises interconnecting polyols with epihalohydrin in the presence of substantially an equimolar amount of base based on the epihalohydrin thereby forming an extended polyol with terminal hydroxyl groups and at least one hydroxyl group attached directly to the backbone chain internally. These resultant polyols can be used to make polyurethane foams having high resiliency. | 2 |
FIELD OF THE INVENTION
This application claims the benefit of U.S. Provisional Application Ser. No. 60/765,162, filed on Feb. 6, 2006 which is incorporated herein by reference. The present invention is directed to a force transmitting apparatus providing an engine producing mechanical. The device as herein disclosed and described, relates to an apparatus employing the forces of buoyancy upthrust on a series of rotationally engaged floatation members to transmit a displacement force to a drive chain or chain engaging bellowed floatation members between two vertically displaced polygonal drive frames formed of individual linear segments. The resulting combined aggregate buoyancy upthrust from the engaged flotation members is utilized to impart rotational movement to mechanically engaged axles or belts.
BACKGROUND OF THE INVENTION
Industrialized countries throughout the world in the 20 th and 21 st centuries have an increased requirement for energy proportional to their populations and production of products for national and international consumption. Conventionally, water power such as dams and fossil fuels such as oil and gas, have provided the world with their main source of energy for industry and for every more energy dependent populations.
With the increase in the world's population and the industrial output of new industrialized nations such as China, combined with ever decreasing natural energy resources, there is an increasing need to find alternate energy sources. It is preferable if such sources are non-polluting due to the theory of global warming from burning fossil fuels and the problems with pollution that oil cause in the world's environment.
As a result, greater emphasis is increasingly being placed on creating more efficient mechanical devices which either operate more efficiently, or which produce energy, in an attempt to conserve current resources. However, it is currently being recognized that many alternative energy sources exist such as wind power, which are being under utilized. Further, many potential non-polluting, renewable natural energy resources, such as gravity and solar energy, are currently under exploited. The apparatus herein described and disclosed, utilizes the natural power of buoyancy to provide an upthrust upon a series of the bellowed floatation members and a unique manner of circulating the floatation members in a flexible chain, to produce a driving force which may be mechanically capture to power mechanical devices to do work.
As is well known, a floating body or member, such as a sealed hollow container, if held below the surface of water, and then released, will rise vertically upwards toward the surface. It is also conventionally known that the water exerts an upward force on the floatation member according to the Archimedes principle. This principle provides that the magnitude of the upward force exerted onto the floatation members is equal to the weight of water which is displaced by the volume of the floatation members. Further, if the total volume of a floatation member displaces water weighing less than the member itself, that member will sink.
As such, there is an ongoing need for new energy sources which take advantage of naturally available sources. Such a device should therefore be provided that will harness the energy provided by the natural upward rise of floatation members and other components which displace sufficient water or fluid and allow for recompressing of such floatation members with minimal energy loss to thereby provide a net gain in upward force which may be harnessed.
With respect to the above description, before explaining at least one preferred embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangement of the components or steps set forth in the following description or illustrations in the drawings. The various apparatus and methods of the invention are capable of other embodiments and of being practiced and carried out in various ways which will be obvious to those skilled in the art once they review this disclosure. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
Therefore, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for designing of other devices, methods and systems for carrying out the several purposes of the present buoyancy engine. It is important, therefore, that the objects and claims be regarded as including such equivalent construction and methodology insofar as they do not depart from the spirit and scope of the present invention.
Further objectives of this invention will be brought out in the following part of the specification wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.
SUMMARY OF THE INVENTION
The device as herein described and disclosed, employs a unique indirect means to compress air or gas inside a hollow bellowed floatation member using indirect compression of the floatation members and gas sealed therein. While the specification herein refers to the hollow bellowed members as floatation members, this term is for convenience and alternate terms for the unique compressible members can also be employed. A segmented polygonal shape of upper and lower frames providing rotational engagement the chain-engaged floatation members and takes advantage of the principle that where forces which are equal and collinear, and are acting in opposite directions, they will not produce a resultant moment at any point in space. Consequently, the pre-pressurized hollow collapsible flotation members, rotationally engaged in a plurality of chained circular paths around both frames, are compressed starting at a widest point in their rotation around the segments of the upper frame section and decompressed beginning at the narrowest point of their rotation around the segments forming the lower frame section. The resulting rotationally engaged combination of compressed and enlarged floatation members, in a plurality of chained engagements to the frames, provide a net upward force to the flexible drive chains engaging each of the plurality of hollow compressible flotation members.
The above noted indirect compression is attained by the employment of circular members centrally engaged upon each linear segment or leg forming the top frame section. The individual segments forming both the upper and lower frames, are engaged to adjacent segments to form a polygonal frame with a generally circular shape. All of the segments forming each respective polygonal frame, rotate in tandem engaged to adjacent segments by means for flexible engagement such as a universal joint. The individual segments engaged to the circular members, the flexible drive chains engaged to the circular members, and dividing members engaged to the chains and sides of the floatation members, and other components engaged to the circular members or segments or chain, will all rotate at substantially the same speed.
A plurality of the flotation members having collapsible sidewalls are engaged between each pair of rotating flexible chains thereby providing means for rotation, translation and a spaced relationship, in between and around the upper and lower frame members in a generally circular path.
The circular planar members are engaged at a central portion of the individual linear segments substantially normal to the axis of individual linear segments. The polygonal shape provided by the individual segments causes the opposing side portions of each pair of circular planar members outside the circumscribed area of the upper and lower frames to be spaced a larger distance from each other than the respective opposite side portions rotating inside the circumscribed area of the frame. Dividing endwall members and the flexible chains on which they are engaged follow alternating narrowing and widening pathways during their rotation around the upper and lower frames. The result is a plurality of narrowing distances between each pair of planar circular members as they rotate on the upper frame from outside the circumscribed area to inside the circumscribed area, and, a plurality of widening distances as they rotate from the inside of the circumscribed area of the lower frame, toward the outside of the circumscribed area.
During rotation of the flotation members in chained or other means for segmented flexible engagement adjacent to each pair of planar circular members engaged to segments forming the upper frame segment, each of the pre-pressurized flotation members is compressed to a collapsed position following the path formed by the endwall members following the narrowing gap between the circular members engaged to the linear segments of the upper frame. In the collapsed position, the floatation members may have a volume that will displace water weighing greater than, equal to, or less than the weight of the floatation member itself.
Each of the plurality of floatation members is engaged between adjacent flexible chains or other flexible segmented engagement to positions wherein all the flotation members are horizontally aligned with respective adjacent floatation members engaged to adjacent flexible chain pairs. On all such engagements of the floatation members to the flexible chain segments, each flotation member is substantially equidistant from the preceding and subsequent flotation member in like engagement. The result is a plurality of flotation members in engagement with chain segments located a fixed distance from other such engagements on the plurality of paired chains, rotating between the narrowing and widening paths formed by the rotating circular members. As noted, all of the linear segments forming the upper and lower frames, are engaged to adjacent segment members in the frame, using means for rotational flexible engagement of the distal ends of the segments to adjacent segment distal ends, such as a universal or rotating joint. Consequently all components rotate around the segments forming both frames at the rotation speed of the segments.
The pressurized flotation members descending, in a mechanically locked collapsed position, from inside the circumscribed area of the upper frame, to the inside of the circumscribed area of the lower frame, thereafter rotate around the lower frame section from inside its circumscribed area to the outside. The path follows the path formed by the circular planar members engaged to individual segments forming the lower frame from a narrowest point to a widest point and each floatation member is caused to inflate to its pre-determined expanded dimension by releasing a mechanical lock and allowing the force of the compressed gas inside the sealed flotation member to expand the collapsed sides. As noted, this enlarged dimension yields a volume that displaces water weighing more than the weight of the flotation member, thereby producing an upward thrust on the enlarged flotation members. This upward thrust is communicated by all of the plurality of inline enlarged flotation members to their respective engagements to the flexible drive chains. Mechanical means for engagement to capture the force of the resulting rotating segmented drive chains, and communicate it, will thereby provide force to do work.
It is therefore an object of the present invention to provide an apparatus and method to produce power from the buoyancy upward thrust on a system of submerged flotation members which may be harnessed.
It is a further object of this invention to use a unique configuration of polygonal frames and compression components rotating in a circular engagement, to minimize energy loss during compression of the flotation members.
An additional object of this invention is the provision of such a buoyancy engine which is easy to develop, construct, maintain and operate.
These together with other objects and advantages which become subsequently apparent reside in the details of the construction and operation of the invention as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part thereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings which are incorporated in and form a part of this specification illustrate embodiments of the disclosed buoyancy engine and together with the description, serve to explain the principles of the invention.
FIG. 1 depicts a side cut away view showing one engagement of circular rotating floatation members endwalls to the chain.
FIG. 2 depicts a partial perspective view of the rotational motion of the chain engaged floatation members endwall in between and around the upper and lower polygonal frames following the narrowing and widening pathways defined by the circular planar members and rails.
FIG. 3 depicts a top view of the device showing the plurality of floatation members in respective spaced engagements on respective flexible chains all engaged at the widest point of the pairs of angled circular planar members.
FIG. 4 is an end view of the one of a polygonal frame, showing the individual rotationally engaged segments and floatation members within the angled pathways defined by the circular members.
FIG. 5 depicts a graphical representation of the angles and dimensions involved between adjacent circular members when operatively engaged at a central portion of the individual segments forming the upper or lower frames.
FIG. 6 shows a compression member endwall in operative engagement between the flexible chain drive and a flotation member adjacent to a rail in a parallel path.
FIG. 7 shows an end view of the mechanism employed to lock the restraining cables in either extended or retracted positions by the pin activated by traversing the eccentric rails.
FIG. 8 shows internal retractable cables which provide a means to restrain the floatation members in both a collapsed state and when they enlarge.
FIG. 9 shows a modified circular planar member in rotational engagement with vertical riser and support bearing.
FIG. 10 shows a modified edge of the floatation member endwall for engagement with a modified circular planar member.
FIG. 11 shows a support arrangement for a non-modified circular planar member.
FIG. 12 shows a modified chain pin, guide roller, and rail guide for use in conjunction with a modified circular planar member.
FIG. 13 show a power take-off arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings FIG. 1-13 , wherein similar parts are identified by like reference numerals, there is seen in FIGS. 1 and 2 side and side perspective views of a single segmented chain assembly 12 which when engaged in a plurality for rotation around an upper frame 14 and lower frame 16 provide a means for compression and expansion of a plurality of floatation members 17 engaged in a spaced positioning between a flexible chain 18 and side rails 20 or upper and lower eccentric rails 30 . The chain is formed of individual segments of substantially equal length. The upper frame 14 and lower frame 16 are in a fixed spaced relationship using vertical risers 31 therebetween, or other structural means to maintain a fixed spacing.
The upper frame 14 and lower frame 16 are polygonal having a generally circular appearance and are formed of individual linear segments 22 . The individual segments 22 which form the upper and lower frames, are engaged to adjacent segments 22 to form the polygonal frames using means for rotational engagement such as a universal joint 24 . The segment 22 so engaged is adapted for rotational engagement with vertical support 48 . The modified circular planar member 26 , in fixed engagement with linear segment 22 , is adapted for rotational engagement with vertical riser 31 which holds the upper and lower frames parallel to each other and at a fixed distance therefrom. The vertical risers are also adapted to be used as a main support structure wherein the other support member will be engaged.
The total number of segments 22 forming the upper and lower frame are equal such that both frames are the same size and when in a fixed engagement to the vertical risers 31 and vertical support 48 , all the segments 22 of the upper frame 14 will be parallel and aligned with all of the respective segments 22 forming the lower frame. Some, or all of the segments 22 forming each respective polygonal frame, are adapted to rotate with vertical risers 31 . The remaining linear segment 22 not in engagement with vertical riser 31 and modified circular planar member 26 , will be supported by vertical support 48 . Design considerations will determine if vertical risers 31 are positioned upon each segment 22 and its paired segment 22 on the opposite frame, or just some of them. The vertical risers 31 will also be employed to operatively maintain the device to the ground or mounting surface upon which it rests during operation.
At a center section of each segment 22 is engaged one of a plurality of planar circular members 26 each being at an angle substantially normal to the axis of its respective engaged segment 22 . As can be seen in FIGS. 3 and 4 the polygonal shape provided by the individual segments 22 forms an angled passage 28 between each pair of circular members 26 . This angled passage 28 is wider outside the circumscribed area of the upper and lower frames and narrower inside the circumscribed area of the two respective frames.
Each of the circular members 26 being engaged to a central portion of each segment 22 rotate at the same speed as the segment 22 to which it is engaged. As noted the segments 22 forming the polygonal frames are linked at their distal ends to adjacent segments 22 and all rotate at substantially the same speed in unison. This imparts a like rotation at an equal speed to all of the engaged circular members 26 .
The flexible chain 18 is operatively engaged to each circular member 26 and properly tensioned in a circular rotation around both the top frame 14 and lower frame 16 rotating at the same speed as the engaged segments 22 and circular members 26 . Spaced from the perimeter of each circular member 26 on the upper and lower frame, and from the flexible chain 18 extending between inline circular members 26 on the top and bottom frames, are guide rails 20 that are each engaged a fixed position by operative mounting to the vertical risers 31 or other means for holding the rails 20 in a fixed engagement substantially parallel to each other. Eccentric rails 30 are in an eccentric spacing to both the upper and lower frames in relation to respective adjacent circular planar members 26 . A bearing 34 or similar means for supported rotational engagement, provides means for engagement of the modified planar circular member 26 to the vertical risers 31 supporting the upper and lower frames. A bearing 46 or similar means for supported rotational engagement of the circular planar member 26 to the vertical support 48 supporting the linear segment 22 .
A plurality of the floatation members 17 are engaged to the flexible chain 18 in a fixed spacing from other floatation members 17 in the plurality engaged to the chain 18 . As such, as the chain 18 rotates in its engagement with the circular members 26 , the floatation members 17 will rotate at the same speed, in their spaced relationship. The guide rails 20 are in operative slidable engagement with the floatation members 17 by means of rollers 40 operatively positioned on endwalls 33 . The eccentric rails 30 are in operative slidable communication with the flotation members 17 using roller 40 positioned at the distal end of pin 42 . The other guide rail 20 is in operative slidable engagement with the connecting pins 41 by means of roller 40 being operatively positioned at the ends of the connecting pins 41 . Positioned along the chain 18 in the space between the inline circular planar members 26 of the upper and lower frames are rails 20 substantially parallel to the outer positioned rails 20 that are fixed in position by operative engagement to the vertical risers 31 or other means for holding the rails 20 in a fixed engagement substantially parallel to each other. The path defined by the planar member 26 , the chain 18 , and the rails 20 is the path that endwall 33 of the floatation members 17 will follow as the members 17 ascend and descend between the upper and lower frames and around the segments 22 of the upper and lower frames.
In this engagement with the chain 18 the floatation members 17 follow the path of the individual segments of the chain 18 in their rotation over the top of the upper frame 14 from outside its circumscribed area to inside its circumscribed area and thereafter toward the lower frame 16 where they follow the path of rotation from inside the circumscribed area of the lower frame 16 and around to outside of the circumscribed area, thereof.
Each of the floatation members 17 have sidewalls 32 having means for repeated compression and expansion such as a bellows 35 or accordion shaped of sidewall 32 and are formed of material adapted for continuous compression and expansion without failure from fatigue. This sidewall 32 thereby provides means to shorten the sidewall through compression on the endwalls 33 of the floatation members 17 . This is a most preferred component of the device since the segmented polygonal shape of upper and lower frames providing rotational engagement the chain-engaged floatation members 17 takes advantage of the angled pathways defined by the angled positioning of the paired circular members 26 and the principle that where forces which are equal and collinear, and are acting in opposite directions, they will not produce a resultant moment at any point in space. As such, as noted above, the flotation members 17 being hollow bellowed such that they are adapted to change from an expanded position having a maximum volume to a collapsed position having a minimum volume, are urged to a compressed position starting at a widest point in their rotation around the segments 22 of the upper frame 14 section and subsequently decompressed beginning at the narrowest point of their rotation around the segments 22 forming the lower frame 16 . The resulting rotationally engaged combination of compressed and enlarged floatation members 17 , and employment of equal, opposite, and collinear forces on the narrowing and widening paths to change the dimensions of the members 17 , and uniform rotation of the entire system, provide a net upward force to the chain assembly 12 engaging any plurality of the floatation members 17 .
During rotation of each of the plurality of flotation members 17 in operative engagement with their respective chain assembly 12 through the angled pathway defined by each angled pair of planar circular members 26 each of the flotation members 17 is collapsed through equal opposite and collinear forces to a collapsed position while traversing the narrowing pathway around the upper frame 14 . Once in this collapsed position, the floatation members 17 are held by means for restraining the floatation members 17 in the collapsed position as they descend toward the interior of the lower frame 16 .
The flotation members 17 descending in the collapsed position from inside the circumscribed area of the upper frame 14 traverse through the interior of the lower frame 16 and thereafter rotate through a widening pathway defined by the angled positioning of the paired circular members 26 engaged to segments 22 on the lower frame 16 . During traverse through this widening pathway, a release of the means to restrain the floatation members 17 in the collapsed position is affected thereby allowing sealed flotation members 17 to expand the collapsed sidewalls 32 as the floatation member 17 traverses around the circular planar member 26 on the lower frame 16 and thereby return to the expanded position.
As can be seen in FIG. 3 which is a top plan view of the device 10 the plurality of respective floatation members 17 are in respective spaced engagements between respective flexible chains 18 and rails 20 on the sides and proceed in a path around the planar members 26 where the chain 18 engaged to the endwalls 33 of the floatation members 17 follow the path defined by the chain 18 and rail 20 and planar members 26 rotating with the linear segments of the upper and lower frames. They, thus, move over the top of the upper frame 14 from outside its circumscribed area to inside its circumscribed area and thereafter toward the lower frame 16 . A similar but a reverse path of rotation over the lower frame 16 is provided by the chain 18 and rail 20 and circular planar member 26 on the lower frame 16 .
The narrowing pathways and employment of the equal, opposite and collinear force provided by the narrowing angled pathways 28 and rotating planar members 26 on the upper frame 14 provide a defined narrowing pathway yielding the compression for the floatation members 17 and as noted take advantage of forces which are equal and collinear, and are acting in opposite directions to compress the flotation members 17 as they traverse over the top of the upper frame 14 .
The compression is accomplished as such, with little or no resistance force as the endwalls 33 of the flotation member 17 are compressed inward during travel through the angled passage 28 formed between the rotating planar members 26 .
A graphical representation and mathematical equation of the dimensional relationship between the indicated variables between adjacent circular planar members as shown in FIG. 5 where
“R”=distance from point “M” to the center of a circular planar member 26 , “r”—radius of the circular planar member 26 , “D”=diameter of the collapsible floatation member 17 “2θ”=angle in degrees between two adjacent planar members 26 Also shown in FIG. 5 is the relationship between “R”, “r” “θ” and “D” is defined by the equation below.
X
y
=
[
(
R
+
r
)
-
D
/
2
cos
θ
]
[
(
R
-
r
)
+
D
/
2
cos
θ
]
Letting X/y be expressed as compression ratio. (ratio of initial cylinder length to final cylinder length). Examination of the above equation will give the following conclusions:
1. Doubling “R” decreases the compression ratio. 2. Doubling “r” increases the compression ratio. 3. Doubling “θ” (small angles) produces insignificant changes on the compression ratio. 4. Doubling “D” decreases the compression ratio.
From the above equation, “r” has the greatest effect on the compression ratio, hence “r” will mostly dictate in the design of the device to yield the most substantial energy gain from the system.
FIG. 7 depicts the registered engagement of the plurality of floatation members 17 in their respective travel around the planar members 26 engaged with the segments 22 on the upper and lower frames, is provided by compression members 38 and 39 . Compression members 38 and 39 are operatively engaged to the endwalls 33 of each floatation member 17 thereby providing means to compress the floatation members 17 to the collapsed position as they travel through the angled passage 28 on the upper frame 14 .
During this travel the segments of the flexible chain 18 engaged to a sprocket or other means for engagement rotate at substantially the same speed as the rotation of the planar member 26 to which they are engaged. The first end of the compression members 38 are rotatably engaged to connecting pins 41 of segments of the chain 18 and the second end of the compression members 38 are slidably engaged to endwall 33 of the floatation member 17 . The sliding engagement of compression members 38 will allow for the changing distance between endwall 33 and the connecting pins of the chain 18 as the floatation member rotates with circular member 26 around the segment 22 of the upper and lower frames 14 and 16 . A stopper on member 38 is provided to maintain an equal gap between the chain 18 and the adjacent edge of endwall 33 when the chain 18 is not in contact with the circular planar member 26 . Compression member 39 is rotatably engaged to the chain 18 on one end and on the opposite end is in a fixed engagement with the endwall 33 . This rigid engagement to the endwall 33 provides a means to maintain the member 39 in a radial direction from the center of segment 22 and means to maintain at a fixed distance, the side of endwall 33 adjacent to chain 18 .
Traversing the circular planar members 26 rotating with the segments 22 of the upper frame 14 , as the pathway 28 narrows, the compression members 38 and 39 move the endwalls 33 of each floatation member 17 to the collapsed position. As best shown in FIGS. 6 and 7 , during travel along the eccentric rails 30 on the upper and lower frames 14 and 16 , a pin 42 is activated to affect engagement of internally located flexible cables 43 from a locked to an unlocked engagement. During the entire time the roller 40 on the pin 42 is in slidable engagement with eccentric rail 30 , the means for volume restraint of the floatation members 17 provided by the cables 43 are in an unlocked position to allow the floatation members 17 to change between the expanded and collapsed position.
During traverse of any one floatation member 17 along the eccentric rail 30 on the upper frame 14 the floatation member 17 is collapsed as noted herein. A roller 40 engaged to the distal end of the pin 42 , traverses the eccentric path of the rail 30 around the axis of the planar member 26 it surrounds. While traversing the upper frame, the roller 40 slidably engaged with the rail 30 , translates the pin 42 toward the center axis of segment 22 , where it disengages the cable housing 45 from the stop 47 . The stop 47 when engaged provides a means to lock the cable housing 45 and the cable 43 extending from it. This allows the endwall 33 to follow the narrowing angled path 28 while the cable 43 changes length to accommodate the changing size of the floatation member 17 .
The cables 43 as noted are located inside the sealed floatation members 17 and are biased to retract onto cable housings 45 operatively located inside the floatation members 17 . As the floatation members 17 collapses as it rounds the upper frame around any respective planar member 26 , the cables 43 are biased into the housings 45 by a biasing means such as internal springs or the like, whereafter the pin 42 is translated to activate the internal restraint mechanism to engage the stop 47 operatively with the housing 45 to maintain the housing 45 in position, and hold the cables 43 in a shorter state. The current preferred means for retracting and extending the cables 43 into fixed relative positions, is shown by restraint mechanism 51 shown in FIGS. 6 and 7 where the pin 42 activated by the roller 40 engaged with the eccentric rails 30 causes translation of the pin 42 to deactivate the restraint mechanism 51 to allow translation of the cables 43 to their respective retracted or extended positions from their housings 45 . While shown as a series of operatively engaged levers cams and springs, those skilled in the art will realize that other means to restrain the cables 43 in either an elongated position in a longer state, or a retracted position in a shorter state, while the floatation members are traveling vertically along the rails 20 may be employed, and such is anticipated.
As the floatation member 17 rounds any planar member 26 located on the lower frame 16 , the eccentric rail 30 engaged with the roller 40 translates the pin 42 toward the axis of the segment 22 moving the restraint mechanism 51 from the locked position to an unlocked position and allowing the cables 43 free to unwind from their housings 45 to the elongated position as the floatation member 17 expands and the endwalls 33 move away from each other to a point where they are fully extended to a pre-determined extended state. As the roller 40 on pin 42 ceases contact with rail 30 the cables 43 are restrained from further elongation by the locking mechanism 51 and provide a means to prevent the floatation members 17 from over expansion. This operation of the locking mechanism 51 to release and then secure the cables 43 to their position of extension from the housing 45 , repeats during each traverse of the upper and lower frames. As noted the pin 42 extends beyond the boundaries of the sealed member 17 . Means to seal the penetration of the pin 42 through the sidewall 32 as well as allow translational motion of the pin 42 through the sidewall 32 is provided by annular seal 44 .
The method and components shown in the drawings and described in detail herein disclose arrangements of elements of particular construction, and configuration for illustrating preferred embodiments of structure of the present invention. It is to be understood, however, that elements of different construction and configuration, and using different steps and process procedures, and other arrangements thereof, other than those illustrated and described, may be employed for providing a buoyancy engine system in accordance with the spirit of this invention.
As such, while the present invention has been described herein with reference to particular embodiments thereof, a latitude of modifications, various changes and substitutions are intended in the foregoing disclosure, and will be appreciated that in some instance some features of the invention could be employed without a corresponding use of other features, without departing from the scope of the invention as set forth in the following claims. All such changes, alternations and modifications as would occur to those skilled in the art are considered to be within the scope of this invention as broadly defined in the appended claims.
Further, the purpose of the foregoing abstract of the invention, is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting, as to the scope of the invention in any way. | A buoyancy engine and compression device having a plurality of rotating flexible chains formed of individual segments, each having a plurality of compressible flotation members engaged thereon. The chains rotate around axises at upper and lower frames. The flotation members are alternately compressed and expanded during rotation around the upper and lower frames during passage through an angled pathway defined by paired planar members in an angled engagement which rotate in time with the chain and engaged flotation members. This alternating compression and expansion may also be utilized as an air compressor. Expanded flotation members circumventing the lower frame produce upward thrust as a function of their dimension and displacement of water. Mechanical energy from the system may be harnessed by conventional mechanical engagement of the rotating flexible chains or segments forming the upper and lower frames. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent Application No. 10-2010-0074672 filed in the Korean Intellectual Property Office on Aug. 2, 2010, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to a channel access method for supporting vehicle communication handover.
(b) Description of the Related Art
Wireless access in vehicular environments (WAVE) is technology that supplements a conventional wireless local area network (WLAN) (IEEE 802.11) method in order to support communication of a vehicle moving at a high speed. Intelligent transport systems using such WAVE communication include roadside equipment (hereinafter referred to as “RSE”) that is positioned at the roadside and on-board equipment (hereinafter referred to as “OBE”) that is mounted in a vehicle and perform vehicle-to-infrastructure (V2I) communications between the OBE and the RSE and vehicle-to-vehicle (V2V) communications between the OBEs.
To continuously provide a communication service under the road conditions to which the intelligent transport system is applied, base stations are disposed so that propagation ranges with neighboring base stations may be overlapped. When the propagation ranges of the base stations are overlapped, the base stations use the same frequency as the neighboring base stations to generate interference and communication problems caused by the neighboring base stations.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
SUMMARY OF THE INVENTION
The present invention has been made in an effort to provide a channel access method for providing a continuous handover skill between a vehicle and a roadside under a vehicle communication environment.
An exemplary embodiment of the present invention provides a method for a plurality of roadside equipments to access a channel to support a vehicle communication handover, including: a first roadside equipment among the plurality of roadside equipments operating a transmitting/receiving mode in a control channel interval of an Nth synchronization interval; a second roadside equipment neighboring to the first roadside equipment among the plurality of roadside equipments operating as a receiving mode in the control channel interval of the Nth synchronization interval; the first roadside equipment operating as the receiving mode in a control channel interval of an (N+1)th synchronization interval; and the second roadside equipment operating as the transmitting/receiving mode in the control channel interval of the (N+1)th synchronization interval.
Another embodiment of the present invention provides a method for a plurality of roadside equipments to access a channel to support a vehicle communication handover, including: a first roadside equipment among the plurality of roadside equipments operating as a transmitting/receiving mode in a control channel interval of an Nth synchronization interval; a second roadside equipment neighboring to the first roadside equipment among the plurality of roadside equipments operating as a receiving mode in the control channel interval of the Nth synchronization interval; the first roadside equipment and the second roadside equipment operating as the transmitting/receiving mode in a service channel interval of the N-th synchronization interval; the first roadside equipment operating as the receiving mode in a control channel interval of an (N+1)th synchronization interval; the second roadside equipment operating as the transmitting/receiving mode in the control channel interval of the (N+1)th synchronization interval; and the first roadside equipment and the second roadside equipment operating as the transmitting/receiving mode in a service channel interval of the (N+1)th synchronization interval.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a diagram illustrating an example of a vehicle communication network for supporting vehicle communication handover according to an exemplary embodiment of the present invention.
FIG. 2 shows a diagram illustrating an example of a WAVE frequency for supporting vehicle communication in the vehicle communication network of FIG. 1 .
FIG. 3 shows a diagram illustrating an example of a synchronization method for performing communication with an alternating mode in the vehicle communication network of FIG. 1 .
FIG. 4 shows a case for a neighboring RSE to access a channel according to an exemplary embodiment of the present invention.
FIG. 5 shows a case of applying a channel access method to an intelligent transport system shown in FIG. 1 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.
Throughout the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.
FIG. 1 is a diagram illustrating an example of a vehicle communication network for supporting vehicle communication handover according to an exemplary embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a WAVE frequency for supporting vehicle communication in the vehicle communication network of FIG. 1 .
As shown in FIG. 1 , in a vehicle communication environment for supporting vehicle communication handover according to an exemplary embodiment of the present invention, an intelligent transport system 10 includes roadside equipment (hereinafter referred to as “RSE”) 100 a - 100 f and on-board equipment (hereinafter referred to as “OBE”) 210 that is mounted in a vehicle 200 .
In such a vehicle communication environment, in order to support communication with a vehicle moving at a high speed, communication is performed in a WAVE method, and an example of frequencies in WAVE communication is shown in FIG. 2 . Referring to FIG. 2 , the WAVE is set to perform communication by allocating a 75 MHz to 5.9 GHz band and using 7 channels of a 10 MHz band. One of 7 channels is a control channel (CCH), and the remaining six channels are service channels (SCH).
When performing WAVE communication, communication may be simultaneously performed in all seven channels, and communication may be performed using one channel at a time. When performing communication using one channel at a time, communication is performed using several channels, and communication is performed in an alternating mode while alternating the CCH and the SCH, as shown in FIG. 3 . In order to perform communication, a synchronization interval 300 , a CCH interval 310 , an SCH interval 320 , and a guard interval 330 of the RSE and the OBE should be set.
Here, the guard interval 330 exists whenever alternating from the CCH interval 310 to the SCH interval 320 or from the SCH interval 320 to the CCH interval 310 . That is, when the RSEs 100 a - 100 f and the OBE 210 perform communication, the guard interval 330 is formed to compensate each time error. In order to perform continuous communication in an alternating mode in such a structure, it is essential to grasp information of the RSEs 100 a - 100 f , particularly a communication channel and a communication state of the RSEs 100 a - 100 f , and when information of the RSEs 100 a - 100 f is effectively grasped, continuous communication can be performed.
In the above-noted vehicle communication environment, in order to provide continuous communication, the RSEs ( 100 a - 100 f ) are disposed to form an interval in which a propagation range is overlapped with the neighboring RSE (hereinafter, a propagation overlapping interval). In this instance, in the case of an operation with the alternating mode in the propagation overlapping interval, the RSEs ( 100 a - 100 f ) access the CCH interval 310 simultaneously with the neighboring RSE to generate interference caused by the neighboring RSE. That is, the RSEs ( 100 a - 100 f ) use the same frequency as the neighboring RSE to cause communication interference.
To solve the above-noted problem, a channel access method for supporting a vehicle communication handover in a vehicle communication environment according to an exemplary embodiment of the present invention will now be described with reference to FIG. 4 and FIG. 5 .
FIG. 4 shows a case for a neighboring RSE to access a channel according to an exemplary embodiment of the present invention.
Referring to FIG. 1 and FIG. 4 , to support a sequential handover, the RSEs ( 100 a - 100 f ) of the intelligent transport system 10 according to an exemplary embodiment of the present invention differentiates the channel access time to access the CCH intervals of different synchronization intervals and perform communication, and thereby prevents the neighboring RSEs from simultaneously accessing the CCH with the same synchronization.
For example, when the RSE 100 a neighbors the RSE 100 b from among a plurality of RSEs ( 100 a - 100 f ) and the vehicle 200 is positioned in the propagation overlapping interval of the RSE 100 a and the RSE 100 b , the RSE 100 a is operable as a transmitting/receiving mode in the CCH interval 410 of the odd-numbered synchronization interval 400 to attempt a channel access and then transmits/receives a data frame. The RSE 100 a is operated as a receiving mode in the CCH interval 510 of the even-numbered synchronization interval 500 to receive a data frame when receiving the data frame from the vehicle 200 . In the transmitting/receiving mode, the corresponding RSE accesses the channel and transmits/receives the data frame to/from the vehicle 200 in the propagation overlapping interval, and in the receiving mode, the corresponding RSE does not access the channel and receives the data frame from the vehicle 200 in the propagation overlapping interval.
In this instance, the RSE 100 b is operable as the receiving mode in the CCH interval 410 of the odd-numbered synchronization interval 400 to receive a data frame when receiving the data frame from the vehicle 200 . The RSE 100 b is operable in the transmitting/receiving mode in the CCH interval 510 of the even-numbered synchronization interval 500 to attempt a channel access, and then transmits/receives the data frame. That is, while the RSE 100 a is operated as the transmitting/receiving mode in the CCH interval 410 of the odd-numbered synchronization interval 400 , the RSE 100 b is operable as the receiving mode in the CCH interval 410 , and while the RSE 100 a is operable as the receiving mode in the CCH interval 510 of the even-numbered synchronization interval 500 , the RSE 100 b is operable as the transmitting/receiving mode in the CCH interval 510 to prevent the neighboring base station from simultaneously accessing the CCH of the same synchronization interval.
The RSE 100 b can access the SCH interval 410 of the odd-numbered synchronization interval 400 and the SCH interval 510 of the even-numbered synchronization interval 500 irrespective of the neighboring RSE.
FIG. 5 shows a case of applying a channel access method to an intelligent transport system shown in FIG. 1 .
Referring to FIG. 1 and FIG. 5 , in the intelligent transport system 10 , when the RSE 100 a neighbors the RSE 100 b from among a plurality of RSEs ( 100 a - 100 f ) and the vehicle 200 is positioned in the propagation overlapping interval of the RSE 100 a and the RSE 100 b , the RSE 100 a is operable as the transmitting/receiving mode in the CCH interval 410 of the odd-numbered synchronization interval 400 and the CCH interval 610 of the synchronization interval 600 to attempt a channel access, and then transmits/receives the data frame. The RSE 100 a is operable as the receiving mode in the CCH interval 510 of the even-numbered synchronization interval 500 and the CCH interval 710 of the synchronization interval 700 to receive the data frame.
The RSE 100 b is operable as the receiving mode in the CCH interval 410 of the odd-numbered synchronization interval 400 and the CCH interval 610 of the synchronization interval 600 to receive the data frame. The RSE 100 b is operable as the transmitting/receiving mode in the CCH interval 510 of the even-numbered synchronization interval 500 and the CCH interval 710 of the synchronization interval 700 to attempt a channel access, and transmits/receives the data frame.
In this instance, the on-board equipment 210 of the vehicle 200 communicates with a single RSE in each synchronization interval. That is, the on-board equipment 210 communicates with the RSE 100 a having attempted a channel access in the CCH interval 410 of the odd-numbered synchronization interval 400 and the CCH interval 610 of the synchronization interval 600 . The on-board equipment 210 communicates with the RSE 100 b having attempted a channel access in the CCH interval 510 of the even-numbered synchronization interval 500 and the CCH interval 710 of the synchronization interval 700 . The on-board equipment 210 communicates with the RSE 100 a or the RSE 100 b in the SCH interval of each synchronization interval to receive a channel service.
In the exemplary embodiment of the present invention, the synchronization interval 400 are the synchronization interval 600 have been shown for the odd-numbered synchronization interval and the synchronization interval 500 and the synchronization interval 700 have been shown for the even-numbered synchronization interval, but the present invention is not restricted thereto, and on-board equipment 210 can communicate with the neighboring RSE by attempting a channel access at different times in the other odd-numbered synchronization intervals and even-numbered synchronization intervals.
Accordingly, when communication is performed by differentiating the time for accessing the channel from the neighboring RSE so as to support the continuous handover skill in the vehicle communication environment according to an exemplary embodiment of the present invention, the communication can be performed without interference with the neighboring RSE, and hence, a seamless service is provided in the fast traveling environment thereby stably supporting the handover skill.
The above-described embodiments can be realized through a program for realizing functions corresponding to the configuration of the embodiments or a recording medium for recording the program in addition to through the above-described device and/or method, which is easily realized by a person skilled in the art.
While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A first roadside equipment operates as a transmitting/receiving mode in a control channel interval of an Nth synchronization interval so as to support a handover. In this instance, a second roadside equipment neighboring to the first roadside equipment operates as a receiving mode in the control channel interval of the Nth synchronization interval. The first roadside equipment operates as the receiving mode in a control channel interval of an (N+1)th synchronization interval. In this instance, the second roadside equipment operates as the transmitting/receiving mode in the control channel interval of the (N+1)th synchronization interval. | 7 |
The present invention relates to laundry facilities. Specifically, a single device for both washing and drying clothes is disclosed using a common heat source for both washing and drying.
Commercial and home laundry facilities have typically required the use of separate appliances for washing and drying clothes, thereby dictating space requirements for the laundry facility. The machines are autonomous in that washing operations occur separate from drying operations, with independent washing and drying cycles and distinct operating controls of there own. A human operator must remove the clothes from the washer and load them in the dryer.
Commercial laundry facilities use larger capacity washing machines to wash clothes, linen and bedding. These facilities, including hospitals, nursing homes, hotels, etc., have a high volume of bedding, towels, and other common materials to wash and dry. Following the washing operation, an attendant must be available to transfer the washed materials to a separate large capacity dryer, and any delays in transferring the material results in a lower facility throughput.
The demands on commercial facilities for clean materials means that laundry facility throughput needs to be efficient and operating at a maximum level. The fact that washers and dryers are autonomous means that an attendant must promptly remove washed materials and load them in the dryer for maximum throughput efficiency, requiring the attention of at least one attendant who might otherwise be available for other tasks.
The high volume demands of these institutions typically means that a separate supply of hot water must be maintained on demand to meet the sanitary requirements for washing clothes which also impacts on space requirements.
The autonomous washing machine produces a load of centrifugally wrung materials which are transferred to a dryer at different times and at varying levels of moisture, depending on operator availability. In establishing an appropriate drying cycle, the beginning moisture level content of the wash load dictates, at least in part, the drying temperature and time for drying. In order to be certain that the drying temperature is at a safe level, so as not to scorch the dried materials, a lower, less than ideal temperature is set for the drying cycle. Accordingly, the drying cycle is longer and laundry throughput is lower than might otherwise be necessary due to each washed load having a different moisture content.
The present invention solves many of the foregoing problems which result from the use of separate autonomous washer and dryer appliances in a laundry facility.
SUMMARY OF THE INVENTION
The present invention provides for a single appliance and method for washing and drying clothes, particularly useful in a commercial laundry setting. In accordance with the invention, a combination washer/dryer is provided which has a common heat source for heating wash water and providing drying air during a drying cycle for the machine.
A sealed containment drum includes a rotating perforated clothes basket for rotating the load to be washed and dried. A water supply plenum extends around the rotating clothes basket and is in heat transfer relationship with a burner unit. The water plenum includes an outlet for discharging wash water through a controllable valve, as well as an inlet for receiving washing water. A drying air chamber extends from an opening in the top of the water plenum for delivering drying air from the heat source to the clothes basket, which passes through the perforated clothes basket to an exhaust chamber which discharges the moisture laden air.
In accordance with a preferred embodiment of the invention, the clothes basket is operated during a spin cycle to centrifugally remove a major quantity of water in the washed materials. In order to avoid caking, or compression of the wash load during a spin cycle, the spin cycle is alternately operated at a plurality of speeds, separated by pauses, to permit the clothing to separate from the wall of the perforated clothes drum.
In accordance with the preferred embodiment, a lint filter is supported in the exhaust chamber. The lint filter is cleaned by a jet of water directed to the lint screen, preferably prior to beginning a washing cycle, so that lint is forced from the filter surface down to the drain in the containment drum assembly to the waste water drain connection.
DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of a washer/dryer in accordance with a preferred embodiment of the invention.
FIG. 2 is a perspective drawing of the washer/dryer containment drum and burner for heating wash water and providing drying air.
FIG. 3 is a perspective view of containment drum.
FIG. 4 is a partial section view of the washing agent container and containment drum.
FIG. 5 is a top view of the washing agent container.
FIG. 6 is a side sectional view of washing agent container.
FIG. 7 is a sectional view of the containment drum and burner for heating wash water and supplying drying air.
FIG. 8 illustrates the washer/dryer cycle as a function of the clothes basket RPM.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 , a perspective view of a washer/dryer in accordance with a preferred embodiment of the invention is shown. A housing 10 encloses a containment drum 11 which is open through the housing 10 and sealed by a door 14 . The containment drum 11 includes a rotating perforated basket 40 inside of a water plenum used for both washing and drying functions of fabrics which are loaded through the door 14 . Exhaust fan 15 provides a negative pressure to draw the moist drying air from containment drum 11 , and expelling the drying air through the exhaust 13 during the drying cycle.
A washing agent container 16 receives washing detergent, bleach, and other washing agents through door 17 , and as in a conventional washer, hose 18 carries the contents of the washing agent container 16 to the containment drum 11 . The plurality of water jets 20 are cyclically operated by controller 12 to wash the contents of each compartment of the washing agent container 16 through the outlet hose 18 . Jet 21 periodically flushes the washing agent container 16 .
Controller 12 provides commands to a motor drive for rotating the basket within containment drum 11 in both washing and drying cycles to produce the washing/drying cycle of FIG. 8 . Additionally, the controller 12 commands an on-board heater to generate heat at the appropriate times during the washing and drying cycles. Temperature sensors within the exhaust 13 and containment drum 11 provide feedback to the controller 12 so that temperatures are maintained at predetermined levels which can sanitize the washing load, and which establish optimum drying temperatures while avoiding excessive temperatures which can damage clothing.
FIG. 2 is a perspective view of the washer/dryer with the housing 10 removed. The containment drum 11 is supported in a frame 29 . Frame 29 is supported via spring 26 to a base 25 . Vibrational forces produced by the rotating basket 40 within containment drum 11 are dampened by shock absorber 27 . Additionally, a front face plate 30 of the containment drum supports the sealed door 14 .
The burner assembly 22 is supported on a burner support 23 fixed to the base 25 . The burner assembly 22 includes burner tubes 21 which supply heat to the containment drum 11 during the washing and drying cycles.
FIG. 3 is a rear perspective view of the containment drum 11 . The shaft 33 for supporting and driving the rotating basket is coupled to a motor (not shown) operated under control of controller 12 . The containment drum 11 has a drain 34 which is coupled via a flexible coupling 35 to a motor operated valve 36 . The motor operated valve 36 is also under control of the controller 12 for discharging wash water at the end of a wash cycle, rinse cycle and spin dry cycle. Also shown is flushing port 38 connected to a water supply valve (not shown) which operates under control of controller 12 for periodically providing a jet of water for ejecting the lint washed from the lint screen through the S shaped trap formed by drain 34 , flexible coupling 35 and valve 36 .
The exhaust fan 15 is shown with the exhaust outlet 13 removed. A drip channel 42 collects water during the spin cycle of the washer/dryer and returns the water back to the water plenum containing the rotating clothes basket.
FIGS. 4–6 are sectional views illustrating the washing agent dispenser compartment 16 with respect to the containment drum 11 and rotating basket 40 . A water inlet 24 supplies water through a solenoid valve under control of the controller 12 to the dispenser compartment 16 which drains due to gravity to the containment drum 11 through outlet 18 . The various washing agents are placed in each of the removable compartments 41 a, 41 b, 41 c, 41 d, and 41 e. Rotation of the door 17 to pivot along the lower edge allows access to the washing agent compartments 41 a, 41 b, 41 c, 41 d, and 41 e. Each individual washing agent compartment is arranged below the jets 20 a, 20 b, 20 c, 20 d, and 20 e. The controller 12 controls a plurality of solenoid valves connected to the various jets 20 to rinse the compartments 41 a – 41 e at the appropriate time where washing agents are dispensed through outlet 18 into the containment drum 11 .
The operation of the combination washer/dryer is now described with respect to FIGS. 7 and 8 . Referring now to FIG. 7 , a sectional view of the washer/dryer is shown. The containment drum 11 includes the rotating perforated basket 40 holding the wash load. During the washing cycle, the water level is established within a water plenum 46 in the containment drum as shown. The water plenum 46 is joined at an opening 49 at the top of the water plenum with the hot air supply plenum 47 . An opening in the bottom of the water supply plenum 46 is joined with an exhaust plenum 48 . During washing, the illustrated water level is confined in the water plenum 46 and the lower portion of the exhaust plenum 48 .
Burner assembly 22 is in heat transfer relationship with water plenum 46 within the containment drum 11 . The burner 22 is operated cyclically under control of the controller 21 to heat water within the water plenum 46 and lower portion of exhaust plenum 48 to a predetermined programmed temperature level, including a sanitizing level as set forth by various regulatory bodies. A temperature sensor 43 provides temperature feedback information to controller 12 so that the correct temperature is established for the washing solution.
The rotating basket 40 reciprocates as is common in most side loading washing machines for a period of time to efficiently clean the load. Once the wash time has timed out in controller 12 , the water is drained from the water plenum 46 through the drain 34 , and the washer/dryer enters the first spin drying mode.
As will be clearer with respect to FIG. 8 , the rinse cycle re-establishes the water to a predetermined programmed level. Once the wash load is rinsed, the water is again drained, and the washer/dryer enters the final spin drying mode under the control of the controller 12 . The basket 40 is rotated at a multiplicity of speeds, coming to rest between each level of rotational velocity so as to prevent the wash load from adhering to the circumference of the clothes basket 40 .
The centrifugally wrung wash load has approximately 50% of the moisture removed from the wash load. During the centrifugal drying of the wash load, moisture spun from the clothes basket 40 may collect in channel 42 where it is returned by gravity to the water plenum 46 and to the drain 34 .
The drying cycle utilizes heat from burner 22 under control of the controller 12 to dry the moisture laden wash load. The hot air supply plenum 47 is formed between the outside wall 28 of the containment drum 11 and a wall 44 of the water plenum 46 . Hot air from the burner 22 rises through the hot air supply plenum 47 and enters the perforated clothes basket 40 at the top of the hot air supply plenum 47 through an opening 49 in the top of water supply plenum 46 . The hot moisture laden drying air is then withdrawn through the bottom of the clothes basket 40 through exhaust plenum 48 . The exhaust plenum 48 extends vertically from lower opening in water plenum 46 substantially diametrically opposite the end of the hot air supply plenum 47 . Fan 15 applies a negative pressure to the opposite end of the exhaust plenum 48 drawing moisture laden air from the perforated clothes basket 40 through the exhaust plenum 48 . The temperature of the drying air is monitored by sensor 45 which is connected to the controller 12 and is disposed at the top of the hot air supply plenum. The drying air temperature is regulated by controller 12 which cycles burner 22 in response to the measured air temperature so as not to exceed a predetermined programmed limit which will damage the wash load 7 . Since the initial conditions for drying including the moisture content of the load are fairly constant between loads, controller 12 may enter a drying routine with a drying temperature profile at its maximum drying efficiency and below a level which will damage the wash load.
A feature of the embodiment in accordance with FIG. 7 includes a lint trap having a filter 51 supported on a tray 50 which can be removed via handle 52 from the exhaust plenum for periodic inspection. Additionally, prior to starting the wash cycle, a water jet 59 may be operated by controller 12 to direct water on the filter forcing lint from the underside of filter 51 . The lint collects in a water pool at the bottom of water compartment 46 . Drain valve 36 is opened by controller 12 and a solenoid operates water valve connected to nozzle 38 is opened forcing the lint load and water to be ejected through drain 36 .
The washer/dryer in accordance with FIG. 7 maybe advantageously operated to provide for a wash/drying cycle under control of controller 12 as shown in FIG. 8 where the wash/dry cycle for the washer/dryer is illustrated with respect to the clothes basket 40 RPM.
The temperature for drying may be optimized for the finished wash load. Since the moisture content is at a known predetermined level, the drying temperature can be safely raised to a higher level than was previously utilized without incurring unacceptable risks of a fire or damage to a wash load.
The sequence of washing and drying begins by activating jet 59 for 5–10 seconds thereby forcing any lint collected on the lint filter 51 into the water plenum 46 and into the drain 34 . The drain valve 36 is opened by controller 12 , and the ejection nozzle 38 supplies a high velocity stream of water for 5–8 seconds flushing any collected residue through the drain 34 .
Following the cleansing of the lint filter 51 and operation of the drain valve, the containment compartment water plenum 46 is filled with wash water to the level shown in FIG. 7 by controller 12 to a predetermined programmed level. The controller 12 then enters a heating mode and enables burner assembly 22 to heat the water in water compartment 46 until the desired temperature is reached.
A wash cycle is entered and the basket is alternately rotated in each direction for a period of time selected by the user through controller 12 . Following the wash cycle, the drain valve 36 is opened and water drains from the water compartment 46 . The machine may then enter a spin cycle to centrifugally force water from the clothes into the drain 34 .
A rinse cycle commences for a period of time set in controller 12 . The water plenum 46 is refilled and the water is heated to an appropriately selected temperature set by controller 12 . The clothes basket 40 is then rotated in alternate directions for the duration of the rinse cycle. Following the rinse cycle, the drain valve 36 is reopened to drain the rinse water.
The spin cycle centrifugally removes 50% of the moisture in the load by initially rotating the clothes basket 40 at about 450 RPM. In order to prevent caking of the laundry load along the surface of the rotating basket 40 , a first pause is entered in the spin cycle for 5–10 seconds, wherein, in the preferred embodiment, the clothes basket 40 stops rotating. At this time, the clothes will drop from the exterior surface of the clothes basket 40 due to the force of gravity. The clothes basket is then operated at a second RPM, at least as high as the initial RPM of 450 RPM, but preferably at a higher RPM of about 750 RPM, to continue centrifugally drying the clothes. The spin cycle is again paused, to permit the clothing to drop from the surface of the clothes basket 40 preventing caking of the clothes to the surface of clothes basket and clumping together in a compact mass. Following a second pause of 5–10 seconds, the clothes basket is rotated through multiple steps to a final spin RPM. The final spin interval, being longer than the first two spin intervals, lasts approximately 4–5 minutes.
The foregoing sequence produces a load of an approximate known moisture content. The beginning of the final heated drying cycle therefore represents moisture conditions which are predetermined and constant from load-to-load. Accordingly, from the known starting point of moisture content, it is possible to select a final optimum drying temperature profile to minimize the time for drying, while maintaining a safe temperature margin for the wash load.
The heated drying cycle begins by actuating valve 36 by closing the drain. The drying cycle may be of the reversing type, wherein the clothes basket 40 is rotated in alternate directions for a predetermined period of time. Following a drying cycle of 30–60 minutes, a cool down cycle is begun wherein the temperature profile of the load is decreased for 3–5 minutes to reduce the possibilities of spontaneous combustion of line lints.
The completion of the drying cycle is signaled by the controller 12 to the facilities operator. From the beginning to end, operator intervention was unnecessary, and personnel involved in the laundry facility are permitted to engage in other tasks. Since the complete washing/drying cycle is automated, maximum throughput efficiency for the facility may be obtained.
The foregoing description of the invention illustrates and describes the present invention. Additionally, the disclosure shows and describes only the preferred embodiments of the invention in the context of a combination washer/dryer having common heat source, but, as mentioned above, it is to be understood that the invention is capable of use in various other combinations, modifications, and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein, commensurate with the above teachings and/or the skill or knowledge of the relevant art. The embodiments described hereinabove are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with the various modifications required by the particular applications or uses of the invention. Accordingly, the description is not intended to limit the invention to the form or application disclosed herein. Also, it is intended that the appended claims be construed to include alternative embodiments. | The combination washer/dryer and method for operating a combination washer/dryer. The washer/dryer has a containment drum which receives wash water, and includes a perforated clothes drum which rotates within the containment drum. A heat plenum is provided in heat transfer relationship with the containment drum, and a source of heat coupled to the heat plenum supplies heat for water in the containment drum. During a drying cycle, hot air from the heat source supplied from the fire box to the containment drum for heating wash water during a washing cycle, and for supplying hot air during a drying cycle. A drying air plenum is connected to receive drying air from the source of heat, delivering the drying air to the top of the containment drum, where it enters the rotating basket. An exhaust plenum discharges hot air laden with moisture from the containment drum through a lint filter. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to power supplies and more particularly to a voltage regulator having an FET inverter stage and an improved driver circuit for that stage.
2. Prior Art
One type of switching regulator which is well known in the prior art employs a full bridge topology for the inverter switches, with each of the four switching devices being driven by an isolated signal. The user of MOSFETS for these main switches allows lower drive power, but due to the desirably fast switching speeds and unavoidably relatively large input capacitance, gate voltage ringing can be a problem. Moreover, power switching circuits are often driven by transformers to provide isolation for the high voltages at reasonable cost. These transformers introduce additional inductances that make control of gate voltage very difficult. Also, the use of transformer coupling between the driver and inverter stages is accompanied by the well-known problem of transformer core "walking", that is saturation of the core due to asymmetrical operation thereof. Prior art solutions to these problems include compromises between switching frequency and the cost of special magnetics designed to reduce voltage spikes, and anti-walkng schemes which reduce efficiency, increase cost, or carry with them resident problems of their own.
SUMMARY OF THE INVENTION
It is a general object of the invention to provide an improved power supply having topological features which overcome the aforedescribed problems of the prior art in a reliable and economical manner.
These and other objects of the invention are achieved by a power supply which provides a transformer coupled drive system for an FET Bridge Regulator that shorts the transformer primary during OFF time of the main switches of the regulator. This shorting removes the effects of the large magnetizing inductance and the associated energy from the secondary circuit of the transformer. With the transformer shorted, the secondary L/C circuit, consisting of the main switch gate capacitances and the transformer leakage and wiring inductances, is much more easily damped. The drive circuit operates from two, interleaved input signals provided by regulator control circuits of the power supply. These signals may have duty cycles ranging from 0 to nearly 50%. Each input pulse produces positive gate signals to one diagonal pair of main switches and negative gate signals to the other pair. When both inputs are OFF, all main switches are biased OFF.
According to one aspect of the invention, an FET full bridge regulator has a driving transformer for the gates of the power FETs of the regulator, and a driving circuit for the primary of the driving transformer, the driving circuit comprising a full bridge formed by first and second sets of driving FETs, which include diodes for reverse, drain-source conduction, each set comprising a complementary pair of FETS and being connected across the transformer primary, one FET of each set being driven ON to together form a conducting path connecting a voltage source across the primary of the transformer and in the absence of driving signals one transistor of each pair conducts forwardly and one conducts reversely to establish a short circuit across the primary. According to still another aspect of the invention, the voltage supply for the driving FETS in the driving circuits of the primary of the driving transformer includes a resistance across which there is developed a voltage proportional to the current drawn by the driving transformer primary in each half cycle of its operation, whereby the voltage applied to that primary is reduced asymmetrically in a corrective direction when the currents drawn during the respective half cycles are not equal.
The foregoing and other objects, features and advantages of the invention will be apparent from the following specification and the drawings forming a part thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a power system including driver and inverter stages in accordance with the invention.
FIG. 2 is a simplified circuit diagram of the driver and inverter stages of the power system of FIG. 1.
FIG. 3 is a set of curves representing drive circuit voltage wave shapes illustrative of the operation of the driver stage shown in FIG. 2.
FIG. 4 is a set of curves representative of current waveshapes in the operation of the driver stage of FIG. 1, for time periods corresponding to those of FIG. 3.
FIGS. 5a thru 5d, show paths of control current and load current during periods "I" through "IV" of the operation as shown in FIGS. 3 and 4.
FIG. 6 shows a simplified equivalent circuit representative of principles involved in the operation of the circuit of FIG. 2.
FIG. 7 shows a set of curves illustrative of the "walking" problem solved in accordance with an aspect of the invention.
FIG. 8 shows a fragmentary detail showing an alternative embodiment of the damping network connected to the gate drives of the main switch scheme of FIG. 2.
DETAILED DESCRIPTION
FIG. 1 shows a power supply system which in gross aspects is similar to many conventional power supply systems. That is, energy derived from an A.C. Source 10 is rectified and filtered at 12 and the resulting D.C. is chopped by switches 14 into pulses which are delivered via power transformer 16 to a rectifier and filter arrangement 18 which delivers regulated and smoothed D.C. to the useful load 20. Typically, in such a system, regulation is achieved by a feedback loop 22 including a pulse width modulation control 24 by which the drive circuits 26 of the main switches 14 are operated in such manner as to vary the width of the pulses delivered to 16 in a manner to compensate for error detected by the loop 22 at the terminal supplying the load 20.
In the system shown, the main switches comprise a bridge arrangement of field effect transistors (FETS) driven via a transformer 28, and the drivers 26 are arranged in a circuit whereby they respond to a three-state control 30 in accordance with the invention to drive the primary 32 of transformer 28 in opposite directions with deadtimes therebetween during which the primary 32 is short-circuited. Also, in accordance with the invention, the complementary drivers 26 are energized via a source 34 which includes means such as a resistor 36 operable to apply voltages to the drivers in accordance with an inverse function of their respective current loads.
The pulse width modulation control 24 in the illustrated embodiment utilizes a ramp signal derived from a current transformer 38 in series with the primary of the power transformer 16. The ramp signal is compared with an error signal, developed by comparing the output DC voltage detected by 22, to yield a Reset A or Reset B signal as determined by an A/B phase signal emitted by a clock unit 40. Clock 40 also provides A Limit and B Limit signals which act as supplementary A Reset and B Reset controls. Clock 40 also provides Set A and Set B signals to the three State Control 30. That Control 30 comprises latches which are set and reset to yield signals A and B as will be described.
FIG. 2 shows simplified circuit diagrams illustrative of a preferred embodiment of the drive 26 and main swtich 14 sections of the power supply of FIG. 1.
The circuit arrangement showsn in FIG. 2 uses four small, low voltage MOSFET's M5, M6, M7, M8, the single drive transformer 28, and five resistors 78, 80, 82, 84, and 36 to achieve the overall function when operated by the signals A and B from the three state control 30 of FIG. 1.
Transistor M5 is a P-channel device the source S of which is referenced via conductor 50 to +Vcc less any drop across resistor 36, and transistor M7 is an N channel device the source S of which is referenced to -Vcc via conductor 52. the gates G of transistors M5 and M7 are connected together and via conductor 54 to control input A of the three state control 30 (FIG. 1). The drains D of transistors M5 and M7 are connected together and to one terminal 56 of the primary 32 of the driver transformer 28.
The control signal applied at terminal A by the three state control 30 is referenced to a "zero" volt level equal to -Vcc so that when the signal at terminal A is up (positive) transistor M5 is OFF and transistor M7 is ON, thereby disconnecting terminal 56 from conductor 50 and +Vcc and connecting terminal 56 to conductor 52 and -Vcc.
Transistor M6 is a P channel device the source S of which is referenced via conductor 60 to +Vcc less any drop across resistor 34, and transistor M8 is an N channel device the source S of which is referenced to -Vcc via conductor 62. The gates G of transistors M6 and M8 are connected together and via conductor 64 to control input B of the three state control 30 (FIG. 1). The drains D of transistors M6 and M8 are connected together and to the other terminal 66 of the primary 32 of the driver transformer 28.
The control signal applied at terminal B by the three state control 30 is referenced to the same "zero" level equal to -Vcc as is the above described "A" signal, so that when the signal at terminal B is up (positive) transistor M6 is OFF and transistor M8 is on, thereby disconnecting terminal 66 from conductor 60 and +Vcc and connecting terminal 66 to conductor 62 and -Vcc.
When the signal at terminal A is down (zero), the gate G of transistor M5 is at -Vcc turning M5 ON, and the gate G of transistor M7 is at approximately the same potential as its source S, depriving M7 of gate drive and turning transistor M7 OFF. Similarly, when the signal at terminal B is down, transistor M6 is ON and transistor M8 is OFF.
FIG. 2 also shows a basic embodiment of the main switch stage 14 in accordance with the invention. Four MOSFET transistors Q1, Q2, Q3, Q4 are connected in a full bridge configuration to gate pulses of current from the +VB terminal of bulk DC source 12 to the main power transformer 16. Gate drive for the main switch transistors Q1, Q2, Q3, Q4 is provided by respective secondaries 70, 72, 74, 76 of driver transformer 28 in response to energization of primary 32 of that transformer, as will be described. Additionally, resistors 78, 80, 82, 84 are provided across the respective drive secondaries 70, 72, 74, 76; that is, between the source and gate terminals of the respective main transistor switches Q1, Q2, Q3, Q4.
Circuit operation will now be described with the aid of waveshapes shown in FIG. 3 and 4, and the current paths illustrated in FIGS. 5a through 5d. Inputs V(a) and V(b) are the signals from the control circuit terminals A and B, FIGS. 1 and 2. These signals are alternately ON positive, have essentially equal ON times and equal timing between the beginning of each pulse. When V(a) is positive, as shown at 100, FIG. 3, drive swtich M7, FIG. 2, is ON and M5 is OFF. M6 will be ON due to the zero level of V(b) which is negative relative to the source terminal S of M6. This results in a positive primary voltage V(p) at terminal 66 relative to terminal 56, and positive gate signals to main switch transistors Q1 and Q4. The other two main switches (Q2 and Q3) will have negative gate voltages as indicated by the dotting on secondaries 72 and 74, and hence will be OFF. The drive transformer 28 will have a primary current I(p), FIGS. 2 and 4, as a result of reflected load current in resistors 78, 80, 82, 84, and due to magnetizing current in transformer 28.
When V(a) returns to zero, as shown at 102, FIG. 3, M7 will turn OFF and M5 will turn ON. M6 remains ON. V(p) and all main gate signals from secondaries 70, 72, 74, 76 now drop to zero, stopping conduction in all main switches Q1, Q2, Q3, Q4. The magnetizing current established in transformer 28 during the ON time must continue to flow. This current, shown at 104, FIG. 4, will flow through transistors M5 and M6 resulting in an effective short-circuit on the primary winding 32. This shorted primary condition is reflected to the secondaries 70, 72, 74, 78 as a low impedance across all gate-source terminals of the main switches Q1, Q2, Q3, Q4, holding them OFF.
When V(b) at terminal B, FIGS. 1 and 2, goes positive as shown at 110, FIG. 3, circuit operation is reversed. M6 turns off, M8 turns on, V(p) is negative an i(p) through primary 32 reverses as shown at 112, FIG. 4. Main switches Q2 and Q3 now conduct. The magnetizing current in 28 decreases and reverses. When V(b) returns to zero, as shown at 114, FIG. 3, M8 turns OFF, M6 turns ON, and the reversed magnetizing current, shown at 116, FIG. 4, flows in M5 and "backwards" through M6. The shorted primary condition is established again and all main switches Q1, Q2, Q3, Q4 are held off.
FIGS. 5a--5d trace the current flow in portion I, II, III, IV of the above described cycle of operation. These figures relate to the voltage and current curves of FIGS. 3 and 4 in accordance with the portions I, II, III, IV delineated thereon.
If the ON (i.e., up) times of V(a) and V(b) are equal, the magnetizing current and core flux of drive transformer 28 will center around zero. Hence, the peak flux in transformer 28 will be one half of the total flux excursion. If the A and B signals from the control circuits do not have exactly the same ON time, "core walking" or asymmetrical magnetic cycling of the core of transformer 28 may result, leading to non-symmetrical magnetizing current. Under these conditions, the voltage drop across resistor 36, FIGS. 1 and 2, during the ON times of signals A and B will be different, tending to reduce the voltage on primary 32 of transformer 28 during the longer ON time and to increase the primary voltage for the shorter ON time. Volt-time unbalance on transformer 28 is thus limited by the drop across resistor 36. Resistor 36 also serves to limit the peak current in the drive switches which occurs when M5 and M7 (or M6 and M8) conduct simultaneously during the transistions of V(a) (or V(b)). Although the internal resistances of M5, M6, M7 and M8 also contribute to the peak current limiting and transformer anti-walking, the external resistor 36, which has a value significantly greater than the operating internal resistance of the MOSFETS M5 through 8, predominates in this effect and does not limit the magnetizing currents 104, 116 during OFF times of the drive control.
FIGS. 6 and 7 summarize the operation of driver section 26 of FIGS. 1 and 2. Transistors M5, M6, M7, and M8 of FIG. 2 are represented by a double pole, triple throw switch 120, each pole having three positions 1, 2, 3. Position 1 corresponds to the A, not B input condition; position 2 to not A, not B condition; and position 3 to the B, not A condition. In the position 1 shown, conventional current flows from +Vcc through balancing resistor 36' to primary 32' terminal 66', through 32' to primary terminal 56', to -Vcc. This state is represented at portion I of the family of curves of FIG. 7. Switch position 2 corresponds to portions II and IV of FIG. 7, and swtich position 3 corresponds to portion III of FIG. 7.
As shown in solid line in FIG. 7 during state or curve portions I and III current ip through primary 32' should be mirror images of each other. Core 28' "walks" , if a shift, delta t, occurs in Vp and ip as shown in dotted line. However, this undesirable condition is corrected by the differential voltage drop in balancing resistor 36'. When the primary current during operation portion I starts to exceed its norm, as shown at delta i, curve portion I, the drop across resistor 36' reduces Vp by delta i times the resistance value of 36', thereby reducing vp during that portion I of the operation so as to bring the operation back into balance or at least restrain it from further drift from balance.
The values of resistors 78, 80, 82, 84 are dictated by the amount of damping required in the secondary circuits driven by transformer 28. The critical time occurs at the end of the ON time when gate signals of two of the main switches Q1, Q4 or Q2, Q3 fall, initiating turn-off. Gate signals to the other main switches go from a negative voltage to zero and, in fact, overshoot positive due to leakage inductance of transformer 28 and gate capacitance of the main switches Q1-Q4. If turn-off of the ON main switches Q1, Q4, or Q2, Q3 is slow and the positive overshoot exceeds the threshold voltage on the OFF devices, both main switches Q1, Q3 or Q2, Q4 on one "leg" of the bridge conduct forming a short circuit across V(b). The values of resistors 78, 80, 82, 84 must be reduced to limit this overshoot to voltages less than the main switch turn-on threshold voltage.
Reducing the values of 78, 80, 82, 84, however, increases the primary current and power dissipation in drive switches M5, M6, M7, M8 and all resistors. An alternative approach to provide damping of the main gate signals is to introduce series resistors 130 as shown in FIG. 8. For the usual range of leakage inductance and gate capacitance encountered, small values of series resistance have a major impact on circuit damping. Hence, the positive overshoot problem can be controlled without significant increase in primary current and overall power dissipation.
The drive circuit must also content with transient voltages produced by drain voltage excursions of the main switches Q1-Q4. Of particular interest is the negative excursion on the drain of a main switch caused by switching of the other device in the same leg. This occurs at nearly the same time as the positive overshoot discussed above. The effect is to produce a negative "spike" on the gate due to coupling through the drain-gate capacitance. The amplitude of this spike must be limited to values less than the gate-source voltage rating. Reducing the values of resistors 78, 80, 82, 84, will reduce the amplitude of this spike but at the same "cost" as above--i.e., increased primary current and overall power dissipation. Note that the introduction of the series resistors alone will increase the spike amplitude.
Also shown in FIG. 8 are additional elements comprising an alternative circuit to limit the spike voltage. A clipping network composed of a diode 132, resistor 134 and zener diode 136 may be added to each main switch gate circuit (Q1 is shown) which will "clip" the negative spike at approximately the zener voltage. This voltage would be selected to be greater than the normal drive voltages but well below the gate-source voltage rating. During positive gate pulses, diode 132 blocks. During negative gate pulses, diode 132 conducts, allowing zener diode 136 to clip the voltage.
Specific designs may, or may not, require the series resistor and/or clipping circuitry, dependent on transformer leakage, MOSFET gate characteristics, and wiring parasitics or trade-off's of circuit complexity vs. control bias power and overall power dissipation may favor the use of one or both of these alternative circuits.
In the foregoing, a current mode control of the ON times of the A and B signals is achieved by use of ramp signals derived by means of the current transformer 38 from the current in the primary of the power transformer 16, in other words, the main switch current rises as energy is delivered to inductance in the output filter of section 18 during the A and B ON times. Alternatively, this ramp function could be provided by a saw tooth generator in the control 24. Both control schemes are well-known. Moreover, the drive circuit 26 may be adapted to provide the drive function in other regulator topologies such as dual switch, half bridge, and push-pull configurations. Also, alternate connection of the P and N channel drive switches is possible and still achieve equivalent operation. Accordingly, although one main embodiment of the invention has been shown and described in detail, it will be apparent that the invention is not limited thereto, but could be otherwise embodied within the spirit of the invention and the scope of the appended claims. | An FET full bridge regulator has a driving transformer for the gates of the power FETs of the regulator, and a driving circuit for the primary of the driving transformer, the driving circuit including a full bridge formed by first and second sets of driving FETs, each set formed by a complementary pair of FETs and being connected across the transformer, primary, one FET of each set being driven ON to together form a series of conducting paths across the primary of the transformer in the absense of driving signals.
The voltage supply for the driving FETS in the driving circuits of the primary of the driving transformer includes a resistance across which there is developed a voltage proportional to the current drawn by the driving transformer primary in each half cycle of its operation for reducing imbalance between the half cycles. | 7 |
This application is a continuation of application Ser. No. 07/351,880, filed May 15, 1989 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a camera with a card accommodating device.
2. Description of the Prior Art
In recent years, a camera is required to have many complicated functions. However, where various functioning means are installed inside a camera, the overall size of the camera increases as much. To the contrary, a functioning device of the adapter type wherein it is exchanged, when it is to be used, for a rear lid of a camera in order to prevent such increase in overall size of a camera has been proposed and is put on the market. Such functioning device, however, inevitably has a greater thickness than an ordinary rear lid of a camera, and accordingly, a considerable increase in overall size of a camera cannot be avoided.
Thus, the present invention has been made to incorporate in a body of a camera an IC (integrated circuit) card accommodating device in which an IC card can be removably loaded in order to expand functions of the camera.
Meanwhile, provision of a card accommodating device in a body of an electronic appliance is already known by itself. Such a card accommodating device is normally provided in an integral relationship on a body of an electronic appliance, and a card is inserted into a card inserting portion of the card accommodating device integrated with the electronic appliance body. A card accommodating device of the type mentioned, however, is not suitably adapted to a camera which is small in size and is carried for use thereof. Besides, the overall size of the camera must still be increased corresponding to a size of the card accommodating device, and the appearance of the camera is deteriorated.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a camera system wherein a card accommodating device can be mounted on a body of a camera without increasing the overall size of the camera body and without deteriorating the appearance and convenience in use of the camera.
It is another object of the present invention to provide a card accommodating device for a camera which is located at a suitable location of a body of the camera and into which a card can be inserted readily.
It is a further object of the present invention to provide a card accommodating device which is suitably applied to a camera which is small in size and carried for use.
It is a still further object of the present invention to provide a card accommodating device which can be integrated in appearance with a camera and assure supporting and loading of a card.
It is a yet further object of the present invention to provide a mounting structure for a camera having a card accommodating device which does not cause an increase in overall size of the camera.
It is an additional object of the present invention to provide a card accommodating device for accommodating an IC card therein which can be suitably adapted to a body of a camera and wherein a switch operating member for setting an additional function can be manually operated readily.
In order to attain the objects, according to one aspect of the present invention, there is provided a camera which comprises a body having a take-up spool chamber formed therein, the body having a grip section which has a battery accommodating chamber formed therein and includes a side wall which defines part of the battery accommodating chamber, the body further having a rear wall and a side wall which extends between the rear wall and the side wall of the grip section, the body further having a spacing formed therein and located rearwardly of the battery accommodating chamber and sidewardly of the take-up spool chamber, the spacing being partially defined by the side wall of the body, and an IC card accommodating device disposed in the spacing and forming part of the side wall of the body.
According to another aspect of the present invention, there is provided camera of the type which has a grip section provided at a side portion of a body, which comprises means provided on a side wall of the grip section and defining an IC card accommodating chamber in which an IC card having a size of 20 mm×30 mm to 40 mm×60 mm is removably loaded.
According to a further aspect of the present invention, there is provided a camera which comprises a body having a recessed spacing formed on a side wall thereof, an IC card accommodating device received in the recessed spacing of the body and forming part of the side wall of the body, and means located at an end portion of the recessed spacing of the body for mounting the IC card accommodating device for pivotal motion from and to a position at which the IC card accommodating device forms part of the side wall of the body.
According to a still further aspect of the present invention, there is provided a card loading device for removably loading a card into a camera, which comprises a card holder supported for pivotal motion on a body of the camera, a card loading section having an opening opposed to an upper face of the card holder such that a card may be inserted downwardly into the card loading section through the opening, and a card ejector located on the card loading section for projecting a card from within the card loading section upwardly to a position at which the card can be manipulated by a finger of a user of the camera.
According to a yet further aspect of the present invention, there is provided a card accommodating device for a camera, which is mounted on a body of the camera for pivotal motion from and to a position at which the card accommodating device is fitted in a recessed spacing of the body of the camera, and which comprises an outer lid unit for removably accommodating an IC card therein, an inner lid unit having switch elements and electric signal transmitting contacts located thereon, the inner lid unit being mounted for movement on and relative to the outer lid unit, and means for releasably arresting the inner lid unit on the outer lid unit.
According to a yet further aspect of the present invention, there is provided a flexible circuit board mounting structure for a camera, which comprises a card accommodating device located sidewardly of a take-up spool chamber of a body of the camera for accommodating an IC card therein, the card accommodating device including a flexible circuit board adapted to be connected to terminals of an IC card accommodated in the card accommodating device, and connecting terminals of signal transmitting contacts located on the body of the camera opposing to a rear lid of the camera, the flexible circuit board in the card accommodating device being connected to the connecting terminals of the signal transmitting contacts.
According to a yet further aspect of the present invention, there is provided a card accommodating device for a camera, which is supported on a body of the camera for pivotal motion outwardly from and inwardly to a position at which the card accommodating device is fitted in a recessed spacing formed in a side wall of the body of the camera, the card accommodating device in the position forming part of the side wall of the body of the camera, and which comprises an outer lid unit for removably accommodating an IC card therein, an inner lid unit mounted for movement on and relative to the outer lid unit, means for releasably arresting the inner lid unit on the outer lid unit, and a switch operating member located on a surface of the inner lid unit.
The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic top plan of a body of a camera showing a location at which a card container device is mounted;
FIG. 2 is a partial side elevational view of the camera of FIG. 1 showing, in a somewhat enlarged scale, a card container device at an open position pivoted away from the camera body;
FIG. 3 is a similar view but showing an inner lid unit of the card container device of FIG. 2 at an open position pivoted to the camera body side;
FIG. 4 is an enlarged horizontal sectional view of the card container device of FIG. 2 but in a closed position accommodated in the camera body;
FIG. 5 is a fragmentary perspective view of an outer lid unit of the card container device of FIG. 2;
FIG. 6 is a fragmentary perspective view of the inner lid unit shown in FIG. 2;
FIG. 7 is an enlarged horizontal sectional view showing an engaging relationship between the outer and inner lid units of FIGS. 5 and 6 with each other;
FIGS. 8a and 8b are sectional views showing an IC card detecting means at different positions;
FIG. 9 is a flow chart illustrating operation of the card container device to be executed in response to the IC card detecting means of FIGS. 8a and 8b;
FIG. 10 is a block diagram showing an IC card detecting circuit;
FIG. 11 is a perspective view of an IC card;
FIG. 12 is a schematic illustration showing a card container device of a different form;
FIG. 13 is a schematic view showing an inner lid unit of a modified card container device;
FIG. 14 is a fragmentary perspective view illustrating an exemplary connection between the inner lid unit and a data receiving contact section of the camera body shown in FIG. 2;
FIG. 15 is a fragmentary perspective view illustrating another exemplary connection between the inner lid unit and the data receiving contact section of the camera body shown in FIG. 2;
FIG. 16 is a sectional view showing a card container device having a card ejecting mechanism;
FIG. 17 is a rear elevational view showing the card container device of FIG. 16 at an open position pivoted away from a camera body;
FIG. 18 is an enlarged horizontal sectional view taken along line 18--18 of FIG. 17 showing the card container device of FIG. 16 at a closed position;
FIGS. 19a, 19b, 19c, 19d, 19e and 19f are a top plan view, a left-hand side elevational view, a front elevational view, a right-hand side elevational view, a bottom plan view and a rear elevational view, respectively, of a single lens reflex camera on which an IC card can be mounted;
FIGS. 20a and 20b are a front elevational view and a rear elevational view, respectively, showing an IC card for use with the camera shown in FIGS. 19a to 19f, and FIG. 20c is a similar view to FIG. 20b but showing a modified IC card;
FIGS. 21a, 21b and 21c are a perspective view, a vertical sectional view and a horizontal sectional view, respectively, showing a card accommodating case;
FIGS. 22a and 22b are perspective views showing another card accommodating case at different positions, and FIG. 22c is a view similar to FIG. 22b but showing a modified card accommodating case;
FIG. 23a is a perspective view showing a further card accommodating case, and FIG. 23b is an enlarged perspective view showing the card accommodating case at a different position;
FIGS. 24a and 24b are perspective views showing a still further card accommodating case at different positions, and FIG. 24c is a side elevational view, partly in section, of the card accommodating device;
FIGS. 25a and 25b are perspective views showing a yet further card accommodating case at different positions, and FIG. 25c is a horizontal sectional view showing detailed structure of the card accommodating case; and
FIGS. 26a and 26b are a perspective view and a sectional view, respectively, showing a yet further card accommodating case.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, there is shown a body of a camera according to the present invention wherein a card container device is mounted at a location of a hatched area. The card container device generally denoted at 42 is normally accommodated in a recess formed in the camera body generally denoted at 41 at a location on the outside of a battery accommodating section and a take-up spool which are disposed in a grip section 44 at a right-hand side portion of the camera body 41. But when an IC card is to be mounted onto or removed from the card container device 42, the card container device 42 is pivoted to a position in which it is projected outwardly from the camera body 41. A lens 43 is provided on the camera body 41.
Referring now to FIGS. 2 and 3, the card container device 42 is shown at such a position as described above at which it is projected outwardly from the camera body 41. Referring also to FIG. 4, the card container device 42 is composed of two principal components including a card holder unit 42a (hereinafter referred to as outer lid unit) for accommodating an IC card therein and a contact holder unit 42b (hereinafter referred to as inner lid unit) for accommodating therein contacts for connection with an IC card. In FIG. 2, the outer lid unit 42a and the inner lid 42b are shown in a mutually engaged or closed condition while FIG. 3 shows them in a mutually disengaged or opened condition. To the contrary, FIG. 4 shows the card container device 42 in an accommodated condition in the camera body 41.
The outer lid unit 42a includes an accommodating section for accommodating an IC card therein, a locking member for coupling the outer and inner lid units 42a and 42b to each other and an accommodating section for the locking member, an IC card display window, and an attracting member securing section for securing thereon an attracting member which also serves as a cover for hole portions formed for decreasing an amount of shrink after molding.
Meanwhile, the inner lid unit 42b includes, in addition to the contacts for connection with an IC card, a switch operating member, and a section for engaging with the locking member of the outer lid unit.
Referring also to FIG. 5, the outer lid unit 42a includes an outer lid 1 having an opening 1f formed therein in which a window portion 2a of a display window member 2 made of a transparent material such as a transparent plastic material is closely fitted to secure the display window member 2 to the outer lid 1. The outer lid 1 has formed thereon a pair of opposite side walls 1a and 1b and a bottom side wall 1c for holding an IC card therein and a pair of opposite side ribs 1d and 1e for supporting an IC card thereon. The outer lid 1 further has a tapered wall 1n formed on the IC card insertion side of the side wall 1b thereof for guiding an IC card to a predetermined loaded position.
The outer lid 1 has a plurality of sink mark preventing holes 1g formed at an end portion thereof, and an attracting member 3 is secured to the outer lid 1 in such a manner as to cover over the shrink mark preventing holes 1g.
A holding plate 4 is securely mounted at a lower portion of the outer lid 1 by means of a fastening screw 18, and an inner lid locking member 5 is interposed between the holding plate 4 and the outer lid 1 and is normally urged by a spring 17 in a direction to engage an arresting projection 5a thereof with an engaging face 9b of a contact cover member 9 which will be hereinafter described. The inner lid locking member 5 has an operating portion 5b for manual operation thereof to move the same relative to the outer lid 1. Here, the inner lid locking member 5 is made of a conducting material. A gap or part of a card chamber 27 is formed between the holding plate 4 and the ribs 1d and 1e of the outer lid 1 such that a leading end portion of an IC card may be inserted into the gap. When an IC card is thus inserted to or removed from the loaded position, it is guided in forward and backward directions by the holding plate 4 and the ribs 1d and 1e of the outer lid 1.
The outer lid 1 has a pair of bearing portions 1h and 1i formed at the opposite upper and lower end portions thereof as shown in FIGS. 3 and 5. A hinge shaft 6 is received in the bearing portions 1h and 1i of the outer lid 1 and thus provides an axis around which the outer lid unit 42a and the inner lid unit 42b are pivoted relative to each other as seen in FIG. 4.
Referring now to FIG. 6, the inner lid unit 42b includes a switch cover member 8 and a contact cover member 9 secured to the switch cover member 8 by means of a plurality of fastening screws 18. A switch member 10 made of a conducting rubber material and serving as a switch operating member, an inner lid base plate 7 to which a flexible circuit board 11 is secured, and a card contact member 12 are interposed between the switch cover member 8 and the contact cover member 9.
Referring also to FIGS. 3 and 5, the inner lid base plate 7 has a pair of bearing portions 7a and 7b provided thereon for receiving the hinge shaft 6 therein to support the inner lid unit 42b for pivotal motion around the hinge shaft 6. The bearing portions 7a and 7b of the inner lid base plate 7 are located between an end face 1j of the bearing portion 1h and an opposing end face 1k of a protrusion 1p of the outer lid 1 on which the hinge shaft 6 is located, and a coil spring 14 is disposed around an outer periphery of the hinge shaft 6 between an end face 1m of the other bearing portion 1i and the other opposing end face 1l of the protruded portion 1p of the outer lid 1 to urge the inner lid unit 42 in its closing direction.
The flexible circuit board 11 secured to the inner lid base plate 7 includes three flexible wiring portions 11a, 11b and 11c for coupling electric signals from the inner lid unit 42b to the camera body 41. The flexible wiring portions 11b and 11c of the flexible circuit board 11 are secured to the front and rear faces of the inner lid base plate 7 so that it is disposed in a folded condition on the inner lid base plate 7 although, in FIG. 6, the flexible wiring portion 11c is not shown secured to the inner lid base plate 7 but shown extending in the same plane with the flexible wiring portion 11b.
Referring to FIGS. 4 and 6, the conducting rubber switch member 10 is held between the inner lid base plate 7 and the switch cover member 8. The conducting rubber switch member 10 has a plurality of switch portions 10a formed thereon which extend through and outwardly from corresponding perforations 8a formed in the switch cover member 8 so that electric signals may be transmitted between the conducting rubber switch member 10 and the flexible wiring portion 11c of the flexible circuit board 11 located on the inner lid base plate 7. The switch portions 10a formed on the conducting rubber switch member 10 are preferably such switches which are not used frequently or which should not be touched inadvertently like a switch for inputting film sensitivity information by manual operation, a switch for rewinding a film before the entire film is used up, or a switch for adjusting the time of a self timer.
The card contact member 12 is held between the contact cover member 9 and the inner lid base plate 7 and located in position by a positioning means not shown formed on the contact cover member 9. The card contact member 12 has a plurality of contacts 12a formed thereon by insert molding. As also seen in FIG. 3, one ends of the card contacts 12a of the card contact member 12 are projected outwardly through a plurality of windows 9a formed in the contact cover member 9 so that they may be contacted with contact portions of an IC card loaded in position on the outer lid 1 of the outer lid unit 42a. The other ends of the card contacts 12a are opposed to the inner lid base plate 7 and connected to the flexible wiring portion 11b of the flexible circuit board 11 mounted on the inner lid base plate 7 so that electric signals may be transmitted between the card contacts 12a of the card contact member 12 and the flexible circuit board 11.
The card contact member 12 has a card detecting contact 12b provided thereon for detecting an IC card loaded in position. The card detecting contact 12b is mounted at a location spaced from the axis of the hinge shaft 6, that is, at a left end location of the card contact member 12 in FIG. 6 and is disposed such that one end thereof may be contacted with at least one of the card contacts 12a of the card contact member 12 while the other end thereof is held in contact with a contact of the flexible wiring plate 11b of the flexible circuit board 11.
Referring to FIG. 6, a ground contact member 21 is mounted on the inner lid base plate 7 and connected at an end thereof to the flexible circuit board 11. The ground contact member 21 is disposed in contact with the engaging face 9b formed on the contact cover member 9.
In particular, the contact cover member 9 has an opening 9c formed at a location thereof corresponding to the arresting portion 5a of the inner lid locking member 5, and the engaging face 9b is defined by one side or end face of the opening 9c of the contact cover member 9. The outer lid unit 42a and the inner lid unit 42b are coupled for integral operation to each other when the engaging portion 5a of the inner lid locking member 5 is held in engagement with the engaging face 9b of the contact cover member 9 as particularly shown in FIG. 7. However, if the operating portion 5b of the inner lid locking member 5 is manually operated to move the inner lid locking member 5 against the urging force of the spring 17, then the inner lid unit 42b is released from the outer lid unit 42a.
Referring back to FIG. 4, the hinge shaft 6 is supported on the camera body 41 at an end portion of a side wall 16b of the grip section 44 which is formed in a projecting manner on the camera body 41 so that it may be gripped by fingers of the right hand of an operator and has a battery accommodating chamber 16 formed therein.
The camera body 41 has a dead space on the right-hand side of a take-up film chamber 15 between the battery accommodating chamber 16 and the rear lid side of the camera body 41, and an outer wall section is disposed in the dead space and extends between the side wall 16b of the battery accommodating chamber 16 and the rear lid side of the camera body 41. The outer wall section is provided by the outer lid 1 which is supported at one end thereof by the hinge shaft 6 and has the attracting member 3 located at the other end thereof for contacting with a magnet 19 provided on the camera body 41.
Referring to FIG. 3, the hinge shaft 6 extends through the bearing portions 1h and 1i formed on the outer lid 1 of the outer lid unit 42a and the bearing portions 7a and 7b formed on the inner lid base plate 7 of the inner lid unit 42b. The hinge shaft 6 further extends through the coil spring 14 which is anchored at an end thereof, though not particularly shown, to the camera body 41 and at the other end thereof to the contact cover member 9 of the inner lid unit 42b to urge the contact cover member 9 to move into the inside of the camera body 41. With the construction described just above, the inner lid unit 42b is normally acted upon by a force to urge the same in a closing direction to move into the camera body 41 by the coil spring 14, and accordingly, the outer lid unit 42a which normally engages with the inner lid unit 42b is normally held at its closing position as shown in FIG. 4 to prevent damage thereto by an inadvertent catch.
As described above, the inner lid locking member 5 provided on the outer lid unit 42a for engaging the inner lid unit 42b and the outer lid unit 42a with each other is formed from a conducting material. Accordingly, when the outer lid unit 42a and the inner lid unit 42b are engaged in an integral relationship with each other, the inner lid locking member 5 is connected and thus grounded to the flexible circuit board 11 by way of the ground contact 21 so that static electricity which may otherwise be accumulated therein may be discharged therefrom.
When the card accommodating device having such a construction as described above is in a normal condition, the outer lid unit 42a and the inner lid unit 42b are held in an integrated relationship with each other by means of the locking means wherein the arresting portion 5a of the inner lid locking member 5 and the engaging face 9b of the contact cover member 9 are engaged with each other. The card container device is held, in the space located sidewardly of the take-up side spool chamber 15 of the camera body 41 behind the battery accommodating chamber 16, at the closing position shown in FIG. 4 at which an outer face of the outer lid 1 thereof serves as an outer wall of the camera body 41. In the position, the attracting member 3 located at the end portion of the outer lid 1 remote from the hinge shaft 6 contacts with the magnet 19 mounted on the camera body 41 so that the magnetic attracting force between the attracting member 3 and the magnet 19 may act to hold the outer lid unit 42a with certainty on the camera body 41 and thus prevent the outer lid unit 42a from being opened inadvertently from the camera body 41.
In this condition, if the outer lid 1 is manually operated to move in the opening direction against the magnetic attracting force between the attracting member 3 and the magnet 19 and the urging force of the coil spring 14, then the outer lid unit 42a and the inner lid unit 42b may be pivoted in an integral relationship to such an open position as seen in FIG. 2. Consequently, a wall face of the switch cover member 8 which constitutes an inner wall of the inner lid unit 42b is exposed outside to allow manual operation of the switch portions 10a of the conducting rubber switch member 10 which are projected outwardly from the switch cover member 8.
An abutting face may be formed on the outer lid 1 of the outer lid unit 42a for contacting, when the outer lid 1 is pivoted in the opening direction toward the camera body 41, with the camera body 41 to define a pivoted position of the outer lid 1. The outer lid unit 42a and the inner lid unit 42b can thus be integrally pivoted to the predetermined pivoted position, and since the direction of manually depressing operation of any of the switch portions 10a of the conducting rubber switch member 10 coincides with the opening direction of the outer lid unit 42a and the inner lid unit 42b, the outer lid unit 42a and the inner lid unit 42b can be held at the open position during manually depressing operation of any of the switch portions 10a of the conducting rubber switch member 10.
In order to cancel the engagement between the outer lid unit 42a and the inner lid unit 42b and load an IC card in position into the outer lid unit 42a, at first the operating portion 5b of the inner lid locking member 5 shown in FIG. 7 is manually operated to move in the rightward direction in FIG. 7 against the spring 17 shown in FIG. 5. Thereupon, the arresting portion 5a of the inner lid locking member 5 is disengaged from the engaging face 9b of the contact cover member 9 to disengage the inner lid unit 42b from the outer lid unit 42a. As a result, the inner lid unit 42b is pivoted toward the camera body 41 by the urging force of the coil spring 14 until it is contacted with and stopped by the abutting face of the camera body 41. In this instance, the outer lid unit 42a is acted upon by no urging force and thus stopped at a position determined by its own weight as seen in FIG. 3. Because the camera body 41 is normally carried with the lens barrel directed downwardly for convenience of operation during camera operations other than photographing operation, the outer lid unit 42a is held in its open condition by its own weight.
When the inner lid unit 42b is in a disengaged condition from the outer lid unit 42a, a surface of the contact cover member 9 of the inner lid unit 42b as seen in FIG. 3 is exposed outside, and consequently, an operator may inadvertently touch with the contacts 12a of the card contact member 12 located on the surface of the contact cover member 9 to damage an IC and so on due to static electricity of the operator. In this connection, in the card container device described above, since the inner lid locking member 5 is formed from a conducting material and grounded to the flexible circuit board 11 by way of the ground contact 15, a possible influence of such static electricity is eliminated at a point of time when the inner lid locking member 5 is manually operated because the static electricity of the operator is discharged through the locking member 5.
An IC card is loaded in position into the outer lid unit 42a while the outer lid unit 42a and the inner lid unit 42b are in a disengaged condition from each other.
In order to load an IC card in position, it is slidably moved from above along a tapered portion 1n formed on the outer lid 1 of the outer lid unit 42a. In this instance, the IC card is moved under the guidance of the opposite side walls 1a and 1b of the outer lid 1 until it is contacted with and stopped at a loaded position by the bottom wall 1c of the outer lid 1. At the loaded position of the IC card, it is placed on the opposite side ribs 1d and 1e of the outer lid 1 and the leading end portion thereof is restricted from movement in a direction of the thickness thereof by the holding plate 4.
Referring to FIG. 11, such an IC card as described above is shown. The IC card generally denoted at 20 has a plurality of lead contacts 20a provided at locations thereof corresponding to the contacts 12a projected through the windows 9a of the contact cover member 9 of the inner lid unit 42b. The IC card 20 has information of a type of the card and so on indicated by printing or the like on the opposite surface 20b thereof to the surface on which the contacts 20a are provided. When the IC card 20 is loaded in position into the outer lid unit 42a, the information indicated on the IC card 20 can be confirmed from outside the camera body 41 through the transparent display window member 2 securely mounted on the outer lid 1.
When the outer lid unit 42a on which the IC card 20 is loaded in position is pivoted so as to be engaged with the inner lid unit 42b positioned inside the camera body 41, the contacts 20a of the IC card 20 are contacted one after another with the contacts 12a projected outwardly from the windows 9a of the contact cover member 9 of the inner lid unit 42b beginning with one of the contacts 20a which is located nearest to the center of the hinge shaft 6. Through such contacting condition between the contacts 20a of the IC card 20 and the contacts 12a of the card contact member 12, the IC card 20 is electrically connected to the camera body side by way of the flexible circuit board 11.
FIGS. 8a and 8b illustrate a relationship between one of the card contacts 12a and the card detecting contact 12b of the card contact member 12. When no IC card is loaded in position in the outer lid unit 42a as seen in FIG. 8b, even if the outer lid unit 42a and the inner lid unit 42b are engaged with each other, the card contact 12a remains at its upper position in which it contacts with the card detecting contact 12b to present an on-state, which represents that no IC card is loaded in position.
If an IC card 20 is loaded in position into the outer lid unit 42a, then the card contact 12a is pushed down by the IC card 20 as seen in FIG. 8a. As a result, the card contact 12a is brought out of contact with the card detecting contact 12b to now present an off-state, which represents that an IC card is loaded in position.
In this manner, whether or not an IC card is loaded in position can be detected by an on- or off-state of the card detecting contact 12b and the card contacts 12a which are operated by an IC card 20 and can be known to an operator from information indicated on the face 20b of the IC card 20 which can be read through the display window section 2 of the outer lid 1 by the operator.
In case an IC card 20 is loaded but not correctly in the predetermined position, for example, if an IC card 20 is loaded with its front face directed rearwardly, also an off-state signal will be derived from the card detecting contact 12b. However, since the contacts 20a of such IC card 20 will not be contacted with the card contacts 12a and remain in an off-state and information will not be transmitted from the IC card 20 to the camera body side, a loaded condition in error of the IC card 20 can be detected. Such detection signal can be applied to give a warning to the operator.
Such application of a detection signal is attained, for example, by such a device as shown in a schematic diagram of FIG. 10. In this instance, a control circuit of the device shown in FIG. 10 may operate in accordance with such a flow chart as, for example, illustrated in FIG. 9. The control circuit thus judges from a current state of a detection switch of the device shown in FIG. 10 whether an IC card is loaded in the card container device (first condition) or not (second condition), and judges, in case an IC card is loaded, whether or not the IC card is loaded correctly in the card container device. Results of such judgement are transmitted to a warning means or a display means of the device shown in FIG. 10 so that a warning may be provided by the warning means or such results may be indicated on the display means.
After it is confirmed that an IC card has been loaded in position into the outer lid unit 42a, the outer lid unit 42a and the inner lid unit 42b which are coupled in an integral relationship to each other with the engaging face 9b of the contact cover member 9 engaged with the arresting portion 5b of the inner lid locking member 5 of the locking means are further pivoted toward the inside of the camera body 41 until the attracting member 3 provided on the outer lid 1 is contacted with the magnet 19 on the camera body 41 to bring the loaded IC card 20 into a condition for use.
While the card container device described above consists principally of the two components including the outer lid unit 42a and the inner lid unit 42b, it may otherwise be constituted from a single principal component.
Referring now to FIG. 12, there is shown an example of mechanism for inserting and removing an IC card wherein an ejecting mechanism is provided to push out an IC card to an ejected position when the IC card is to be removed from a card insertion opening formed in an upper wall or a side wall of a card container device. In particular, the ejecting mechanism is provided at a location remote from an insertion opening of an IC card accommodating chamber which is defined by a base member 31. The ejecting mechanism includes a pushing out member 33 for pushing out an IC card, an operating member 32 manually operable for moving the pushing out member 33 in an upward direction, and an operating member returning spring 34 for normally urging the operating member 32 to hold an IC card at its loaded position. An IC card is thus inserted into the base member 31 through the insertion opening and thereafter held at its loaded position, and when it is to be removed, the operating member 32 is manually operated to move in the leftward direction against the urging force of the operating member returning spring 34 so that the pushing put member 33 is moved upwardly by the operating member 32 to allow removal of the IC card.
The card container device which includes such base member 31 as described above is supported for pivotal motion at a side wall portion of a camera. When an IC card is to be loaded or exchanged, the card insertion opening of the base member 31 is projected outwardly from the camera side wall portion. The card insertion opening of the card container device in which an IC card is loaded in position is positioned inside the camera body and a side wall of the camera container device serves as a side wall portion of the camera similarly as in the card container device shown in FIGS. 1 to 11.
Referring to FIG. 13, there is shown a modification to the inner lid unit 42b of the card container device shown in FIGS. 1 to 11. The modified inner lid unit is denoted at 42'b and includes a contact cover member 109 having a plurality of windows 109a and another pair of windows 109d perforated therein. A plurality of contacts 112a of a card contact member not shown in FIG. 13 extend through the windows 109a of the contact cover member 109 while a pair of contacts 112c of the card contact member extend through the windows 109d of the contact cover member 109 for contacting with an IC card loaded in position to detect presence of such IC card. The contacts 112c thus act similarly as the card detecting contact 12b in the card container device described hereinabove which cooperates with one of the card contacts 12a to detect presence of an IC card loaded in position.
The card contact member 109 further has an elongated friction finger 109e formed thereon. The friction finger 109e is bent at an end portion thereof at an obtuse angle and disposed for frictional engagement with an IC card when the IC card is inserted in position. When the IC card is in position, the friction finger 109e frictionally contacts with the IC card to prevent inadvertent jumping out of the IC card from the card container device.
Referring now to FIG. 14, there is shown an exemplary connection of the flexible wiring portion 11a of the flexible circuit board 11 particularly shown in FIGS. 3 and 6 to a data receiving section disposed in the take-up spool chamber 15 of the camera body 41.
The data receiving section includes a data receiving contact holder 22 located behind the take-up spool chamber 15, i.e., the rear lid side of the camera body 41 and securely mounted on the camera body 41 by means of a pair of fastening screws 23. The data receiving contact holder 22 has a wide recess formed therein, and a data receiving contact cover 24 is fitted in the wide recess and secured to the data receiving contact holder 22 by means of a pair of fastening screws 25 (only one is shown in FIG. 14).
The flexible wiring portion 11a of the flexible circuit board 11 provided in the inner lid unit 42b extends around the hinge shaft 6 (not shown in FIG. 14 but shown in FIG. 4) and has a connecting portion 11d formed at an end thereof remote from the flexible wiring portion 11b. The connecting portion 11d of the flexible circuit board 11 is adhered, by means of a double-sided adhesive tape not shown, to a side wall 15a of the take-up spool chamber 15 of the camera body 41. In order to connect the flexible circuit board 11 to an upper portion of the camera body 41 and data receiving contacts not shown, the connecting portion 11d of the flexible circuit board 11 has provided thereon a connecting pattern portion 11e which is to be connected to a main flexible circuit board not shown located at an upper portion of the camera body 41 and another connecting pattern portion 11f which is to be connected to the data receiving contacts on the camera body 41.
The connecting pattern portion 11e of the flexible circuit board 11 extends upwardly through a slit 15e formed at an upper portion of the side wall 15a of the take-up spool chamber 15 to an upper portion of the camera body 41. To the contrary, the other connecting pattern portion 11f extends rearwardly along the side wall 15a of the take-up spool chamber 15 and around the rear end of the side wall 15a and is disposed on a data receiving contact cover mounting face 22a provided by the bottom of the wide recess formed in the data receiving contact holder 22. The data receiving contact cover 24 on which data receiving terminals not shown are located is placed on the connecting pattern portion 11f of the flexible circuit board 11 mounted on the mounting face 22a of the data receiving contact holder 22 and is thus secured to the data receiving contact holder 22 together with the connecting pattern portion 11f of the flexible circuit board 11 by means of the screws 25.
Referring now to FIG. 15, there is shown a modification to the connection between the connecting pattern portion 11d of the flexible circuit board 11 and the data receiving terminals shown in FIG. 14. In particular, the data receiving contact cover 24 and the data receiving contact holder 22 shown in FIG. 14 are formed as a unitary data receiving contact holder 22. In this instance, a plurality of metal plates 26 which form data receiving contact portions 26b are mounted in the data receiving contact holder 22 by insert molding, and the connecting pattern portion 11f of the flexible circuit board 11 is connected by soldering to connecting projections 26a of the metal plates 26, projected from a side wall 22b of the data receiving contact holder 22. The data receiving contact holder 22 is secured to upper and lower end walls of the take-up spool chamber 15 by means of a pair of fastening screws 23.
Referring now to FIGS. 13 and 16 to 18, there is shown an exemplary form of the ejecting mechanism shown in FIG. 12. The ejecting mechanism is applied to a camera in which there is employed a card container device similar to the card container device shown in FIGS. 1 to 8 except that an inner lid unit 42b and an out lid unit 42a are integrally secured. Therefore, the lid units are indicated as an inner portion 42'b and an outer portion 42'a, respectively. The ejecting mechanism includes a card ejector 28 for ejecting an IC card from its loaded position. The card ejector 28 is mounted for upward and downward movement on the inner portion 42'b of a card container device and normally urged in the downward direction in FIGS. 13, 16 and 17 by means of a spring not shown. As particularly seen in FIG. 18, the card ejector 28 has a card pushing up portion 28a located on an inner face adjacent a free end edge of a switch cover member 108, and a manually operable portion 28b connected to the card pushing up portion 28a and located on the opposite face adjacent the free end edge of the switch cover member 108. The card ejector 28 is thus mounted for upward and downward sliding movement along the free end edge of the switch cover member 108 and is normally held at its lowermost position by the downward urging force of the spring not shown as seen in FIG. 17. The card pushing up portion 28a of the card ejector 28 extends into a gap or card chamber 27 defined between a card contact member 109 and a transparent display window member 102a of an outer lid 101 so that it may engage with a lower end of an IC card inserted in the card chamber 27 as can be seen in FIG. 16.
An IC card 20 is loaded in position into the gap or card chamber 27 between the contact cover member 109 and the display window member 102a from an insertion opening formed at an upper portion of the gap or card chamber 27. When the IC card 20 is to be ejected from the loaded position, the card ejector 28 is manually operated at the manually operable portion 28b thereof and thus moved upwardly in FIGS. 13, 16 or 17. Thereupon, the card pushing up portion 28a of the card ejector 28 is engaged with the lower end of the IC card 20 to push up the IC card 20 from the loaded position to an ejected position defined by an abutting edge 109f of the contact cover member 109 which is engaged with the card ejector 28. At the ejected position, the IC card 20 extends upwardly from the card chamber 27 or the insertion opening by a distance which is sufficient to allow an operator to pick up an upper portion of the IC card 20 but will not allow the IC card 20 to be dropped from the card container device.
During such ejecting movement of the IC card 20, the friction finger 109e described hereinabove of the contact cover member 109 shown in FIG. 13 frictionally contacts with a surface of the IC card 20 to prevent the IC card 20 from being jumped out from the card container device by the urging force produced by resiliency of the contacts 112a or 112c of the card contact member 112.
If the card ejector 28 is released after then, then the card ejector 28 is retracted downwardly to its normal position by the urging force of the spring not shown to allow subsequent loading of an IC card.
Referring now to FIGS. 19a to 19f, there is shown a single lens reflex camera in which an IC card such as the IC card 20 shown in FIG. 11 can be removably loaded. Each of hatched areas in FIGS. 19a to 19f indicates a location of a surface of the camera at which an IC card having an individually suitable size can be removably mounted without changing the configuration of the camera. In particular, as shown in FIG. 19a, on the top of the camera, an IC card can be mounted on a surface of the camera at any of a location A of an upper portion of the camera on the take-up side (i.e., a film take-up spool chamber is located at this side), another location B of an inclined portion on the take-up side of a projected portion of the camera in which a pentagonal roof prism not shown is accommodated, a further location C of another inclined portion on the rewind side (i.e., a film cartridge chamber is located at this side) of the projected portion, and a still further location D of another upper portion of the camera on the rewind side. Meanwhile, on a side wall of the camera as viewed from the grip section side of the camera shown in FIG. 19b, an IC card can be mounted on the surface of the camera at a location E of a take-up side portion of the grip section of the camera in addition to the location B, and on the front side of the camera, as shown in FIG. 19c, an IC card can be mounted at any of a location F of a take-up side front portion of the grip section, another location G of an upper portion of the rewind side front portion, and a further location H of a lower portion of the rewind side front portion. Further, on a lower cover section of the camera, as shown in FIG. 19e, an IC card can be mounted on the surface of the camera at either of a location I of a lower portion adjacent the take-up side and another location J of a lower portion on the rewind side, and on a rear lid section of the camera, as shown in FIG. 19f, an IC card can be mounted at either of a location K of the rear lid section and another location L of the rear lid grip section.
An IC card to be mounted on a camera is preferably small in size, but it is advantageous from a point of view of prevention of loss and facility in handling that an IC card has a size of 20 mm×30 mm to 40 mm×60 mm or so and a thickness of about 1.9 mm. With such configuration, an IC card can be mounted at a location selected from a maximum possible number of locations on a surface of a camera.
Referring now to FIGS. 20a and 20b, there is shown an exemplary IC card for use with such camera as described above. The IC card generally denoted at 120 has such front and rear surfaces 120b and 120c as shown in FIGS. 20a and 20b, respectively. In particular, the front surface 120b of the IC card 120 has thereon a graphical indication from which a user can recognize a program relating to the card 120 and/or a type or contents of the card 120 and/or an indication of a title of contents of the card 120 as seen in FIG. 20a. Meanwhile, the rear surface 120c of the IC card 120 has a plurality of connecting contacts 120a at a location thereof near a longitudinal end of the IC card 120 as seen in FIG. 20b. The connecting contacts 120a are arranged in a row extending perpendicularly to the longitudinal direction of the IC card 120. A portion of the rear surface 120c of the IC card 120 above the connecting contacts 120a remains blank or white so that a user may write some memos on the rear surface portion using some suitable pen.
Since the connecting terminals 120a are arranged in a horizontal row near the longitudinal end of the IC card 120, a user can handle the IC card 120 without touching with the connecting terminals 120a. Further, as contacts for contacting with the connecting contacts 120a of the IC card 120 are disposed at an interior location of such a card container device as described hereinabove, when a user is to insert the IC card 120 in the axial direction and load the same in position into the device, the connecting contacts 120a of the IC card 120 will not touch with any irrelevant portion of the device, and accordingly, the IC card 120 can be loaded correctly.
FIG. 20c shows a rear surface of another exemplary IC card. The IC card shown is denoted at 120' and may have such a front surface as shown in FIG. 20a. In the IC card 120', a plurality of connecting contacts 120'a are arranged in a vertical column along a longitudinal edge of the IC card 120'. Thus, also the IC card 120' has a blank or white portion at which the connecting contacts 120'a are not provided. Accordingly, the IC card 120' can be handled without touching with the connecting contacts 120'a, and a graphical indication or an indication of a title or the like can be provided at the blank portion of the IC card 120'.
Where the IC card has a size of about 20 mm×30 mm to 40 mm×60 mm and a thickness of 1.9 mm and particularly a size of 20 mm×30 mm, a card accommodating section for accommodating such IC card can be provided at a flat surface portion of a camera having a comparatively large area without modifying the configuration of the camera at present. Meanwhile, the IC card has a sufficient size to permit the same to have minimum elements arranged thereon which are required to be arranged on the same such as a ROM IC, bonded wires and contacts.
Referring now to FIGS. 21a to 21c, there is shown a card accommodating section for accommodating an IC card therein. Here, such IC card 120' as shown in FIGS. 20a and 20c is used for the accommodating section. The card accommodating section is provided at a location G of the upper portion of the rewind side front portion of the camera shown in FIG. 19c. The card accommodating section includes a card accommodating section cover 272 mounted at a lower end thereof on a body 252 of a camera for pivotal motion toward and away from the camera body 252 under the guidance of a pivotal guide 271 as seen in FIG. 21a. The card accommodating section cover 272 has a transparent window member 272a through which an indication such as a graphical indication on the front surface 120'b of an IC card 120' loaded in position in the card accommodating section can be observed so that contents of the IC card 120' may be known to a user from outside the camera. A plurality of card contacts 273 are disposed on the camera body 252 in an opposing relationship to the connecting contacts 120'a provided on the IC card 120' loaded in position. The card contacts 273 are mounted in a row on a contact holder 274 secured to the camera body 252 as shown in FIG. 21b. The contact holder 274 has, in addition to the card contacts 273, CAS contacts 276 supported thereon in an opposing relationship to a film magazine chamber 275 of the camera for reading out film sensitivity information coded on a film magazine as shown in FIG. 21c. In this instance, the IC card 120' is accommodated between the card accommodating section cover 272 and the opposing camera body 252 and is thus loaded in position in the camera body 252 with an arresting portion 272b of the card accommodating section cover 272 engaged with an engaging hole 270a formed in the camera body 252.
FIGS. 22a to 22c show a card accommodating section disposed at the location D of the upper portion of the camera on the rewind side shown in FIG. 19a. Here, such IC card 120 or 120' as shown in FIGS. 20a and 20b or in FIGS. 20a and 20c is used. The card accommodating section includes a card accommodating section cover 277 which has a liquid crystal display device (LCD) 277a disposed on an upper face thereof as shown in FIG. 22a. When an IC card 120 is loaded in position in the card accommodating section, a type and contents of the IC card 120 are indicated on the LCD 277a. Further, a pair of operation switches 277b and 277c for selecting a particular one of a plurality of camera body control modes in the IC card 251 are provided on the card accommodating section cover 277. Card contacts for contacting with the connecting contacts 120a of an IC card 120 may be provided on the camera body 252 side as at 278a shown in FIG. 22b or on the card accommodating section cover 277 side as at 278'a shown in FIG. 22c. In FIG. 22a, reference character 270b denotes a projected portion of the camera in which a pentagonal roof prism not shown is accommodated.
In this instance, the card accommodating section cover 277 is mounted for pivotal motion around an axis at a bottom side location of the projected portion 270b of the camera in which the pentagonal roof prism is accommodated. Thus, an IC card 120 or 120' can be loaded in position by placing the same in position on the camera body 252 and pivoting the card accommodating section cover 277 to such a position as shown in FIG. 22a.
FIGS. 23a and 23b show a card accommodating section disposed at the location C of the inclined portion on the rewind side of the projected portion of the camera shown in FIGS. 19a and 19d in which the pentagonal roof prism is accommodated. Here, such IC card 120 or 120' as shown in FIGS. 20a and 20b or in FIGS. 20a and 20c is used. The card accommodating section shown includes a card accommodating section cover 279 located on an inclined face 270b 1 on the rewind side of the projected portion 270b as shown in FIG. 23a. The card accommodating section cover 279 is mounted for pivotal motion around an axis at a bottom side location of the inclined face 270b 1 of the projected portion 270b between such an upper position as seen in FIG. 23a in which it is positioned on the inclined face 270b 1 of the projection portion 270b and a lower position as seen in FIG. 23b in which it lies on the upper surface of the camera body 252 on the rewind side. The card accommodating section cover 279 has a card receiving portion 279a formed on an upper face thereof at its lower position. Thus, an IC card 120 or 120' can be loaded in position on the camera body 252 by placing the same in position on the card receiving portion 279a of the card accommodating section cover 279 at the lower position with the connecting contacts 120a or 120'a of the IC card 120 or 120' directed upwardly and then pivoting the card accommodating section cover 279 in the direction indicated by an arrow mark in FIG. 23b to the upper position. A plurality of card contacts 280 are provided on the inclined face 270b 1 of the projected portion 270b of the camera body 252 in an opposing relationship to the connecting terminals 120a or 120'a of the IC card 120 or 120'.
A card accommodating section disposed at the location J of the lower cover section of the camera body shown in FIG. 19e is shown in FIGS. 24a to 24c. Referring to FIGS. 24a to 24c, the card accommodating section shown includes a card accommodating section case 282 mounted for sliding movement along a recessed portion formed on a lower cover section 281 of the camera body 252. The card accommodating section case 282 can thus be pulled out rightwardly from a position shown in FIG. 24a to another position shown in FIGS. 24b or 24c in which an IC card 120 or 120' can be accommodated into the card accommodating section case 282. The IC card 120 or 120' is normally urged upwardly by a spring plate 282a mounted on the card accommodating section case 282. Accordingly, when the card accommodating section case 282 is pushed to move to the position shown in FIG. 24a, the connecting contacts 120a or 120'a of the IC card 120 or 120' are resiliently pressed against or contacted with card contacts 283 provided on the bottom of the lower cover section 281 of the camera body 252. The IC card 120 or 120' is loaded in position in the card accommodating section in this manner.
FIGS. 25a to 25c show a card accommodating section disposed at the location K of the rear lid section of the camera body as shown in FIG. 19f. Referring to FIGS. 25a to 25c, the card accommodating section is generally denoted at 285 and is formed in an integral relationship on a rear lid section 284 of the camera body 252. A card loading member 286 is fitted for sliding movement in the card accommodating section 285 such that it may be inserted into the card accommodating section 285 through an insertion opening formed at a left end portion of the card accommodating section 285.
The card loading member 286 has a holding portion on which an IC card 120 or 120' can be mounted, and a grip portion provided at an end of the holding portion. Meanwhile, the card accommodating section 285 has a transparent window member 285a formed at a location thereof opposing to an IC card 120 or 120' loaded in position in the card accommodating section 285 so that an indication on a surface of the IC card 120 or 120' can be visually observed through the window member 285a. Further, a plurality of card connecting contacts 287 are provided on the rear lid section 284 for contacting with the connecting contacts 120a or 120'a on the rear surface of an IC card 120 or 120' loaded in position. The other ends of the card connecting contacts 287 on the rear lid section 284 are held in contact, when the rear lid section 284 is mounted in position on the camera body 252, with a flexible circuit board 288 for connection with the camera body 252 as shown in FIG. 25c.
FIGS. 26a and 26b show another card accommodating section disposed at the location K of the rear lid section of the camera body as shown in FIG. 19f. Referring to FIGS. 26a and 26b, the card accommodating section includes a card accommodating section case 289 mounted for pivotal motion on the rear lid section 284 of the camera body 252 between a closed position shown in FIG. 26a in which it lies on the rear lid section 284 and another open position in which a free end thereof is spaced away from the rear lid section 284. An IC card 120 or 120' can thus be loaded in position into the card accommodating section by mounting the same onto the card accommodating section case 289 at its open position and pivoting the card accommodating section case 289 to the closed position.
In particular, as apparently seen from FIG. 26b, the card accommodating section case 289 is supported for pivotal motion around a hinge 290 on the rear lid section 284. As shown in FIG. 26a, an unlocking knob 291 is provided at an upper portion of the card accommodating section case 289 for canceling a locked condition between the card accommodating section case 289 at the closed position and the rear lid section 284 of the camera body 252. Thus, by manual operation of the unlocking knob 291, the card accommodating section case 289 can be pivoted from the closed position to the open position at which an IC card 120 or 120' can be placed onto the card accommodating section case 289. A plurality of card connecting contacts 292 are supported on a portion close to the hinge 290 provided on the rear lid section 284. One ends of the card connecting contacts 292 are disposed for contacting engagement with the connecting terminals 120a or 120'a of an IC card 120 or 120' loaded in position while the other ends of the card connecting contacts 292 are held in contact with connecting terminals 293 for connection with connecting terminals on the camera body 252. The card accommodating section case 289 has a transparent window member 289a formed thereon so that an indication on the front surface 120b of an IC card 120 or 120' loaded in position may be visually observed therethrough.
Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit and scope of the invention as set forth herein. | A camera system wherein a card accommodating device can be mounted on a body of a camera without increasing the overall size of the camera body and without deteriorating the appearance and convenience in use of the camera. The card accommodating device is mounted on the camera body for pivotal motion from and to a position at which it is fitted in a recessed spacing formed rearwardly of a battery accommodating chamber and sidewardly of a take-up spool chamber of the camera body. The card accommodating device at the position forms part of a side wall of the camera body. The card accommodating device comprises an outer lid unit for removably accommodating an IC card therein, and an inner lid unit mounted for movement and releasably arrested on the outer lid unit and having switch elements and electric signal transmitting contacts located thereon. | 6 |
RELATED APPLICATION
[0001] This application is a continuation of application Ser. No. 10/018,372, filed Dec. 12, 2001, which was filed as the National Stage of International Application No. PCT/EP00/05208, filed Jun. 7, 2000, which claims priority under 35 U.S.C. § 119 from German application 199 26 889.4, filed Jun. 12, 1999, the content of all of which are incorporated by reference in their entirety. Applicant claims the benefit of 35 U.S.C. § 120.
FIELD OF THE INVENTION
[0002] The invention relates to a plastically deformable implant.
BACKGROUND OF THE INVENTION
[0003] Such plastically deformable implants are used, for example, in ophthalmology, in particular as vitreous body or lens replacement, and in dentistry, for example, for filling cavities left after tooth extraction in the jaw bone.
[0004] In addition, in plastic surgery, it is known to use deformable implants which, however, invariably comprise a cushion-like envelope and an implant material as a filler, thus providing a barrier with respect to the surrounding tissue and thereby ensuring biocompatibility.
[0005] For ophthalmological applications, fluorine-containing compounds in the form of readily moving liquids and preparations are known. In this field of application, the properties typical for fluorine-containing compounds, such as high density and low surface tension, are utilized. The partially fluorinated and perfluorinated compounds so far used, however, are single-phase liquids. As a result, varying material properties can be utilized only to the extent defined by the structure and the inherent properties of the chemical compounds used. Thus, with the conventionally known fluorine-containing ophthalmological preparations it is not possible to meet the frequently highly different and in part opposite requirements of the preparation with one single material component.
[0006] Thus, for example, during and after vitreoretinal interventions, a preparation is needed which has excellent tamponade properties and, at the same time, offers the possibility of an exchange of water-soluble substances, which cannot be simultaneously achieved with the well-known ophthalmological preparations since these do not mix with water. In addition, an attempt was made to avoid injury to the retina—which is observed during the ophthalmological application of perfluorocarbons and which is to be attributed to mechanical effects—by using substances with a lower density, such as those described in European Patent No. 563 446 B1 and German Patent Nos. DE 197 19 280 and DE 195 36 504 A1. Unfortunately, this entailed a simultaneous increase in the lipophilic properties of these compounds, which led to penetration. As a result, histological changes as well as side effects similar to those known from perfluorocarbons were observed.
[0007] In addition, in prior art, it has been known to use fluorine-containing gels of the class of fluorocarbon-water emulsions. Emulsions in the form of gels of this type and their possible applications in medicine and technology have been described, for example, in U.S. Pat. No. 5,573,757, in European Patent No. EP 0 340 079, and in International Patent No. WO 97/03644. These gels form polyaphron structures with a continuous minority phase and a discontinuous majority phase. During this process, the minority phase completely encapsulates the majority phase and thus determines the most important properties of the overall preparation. As known from prior art, a very specific working sequence must be followed in order to produce preparations with this type of structure. Furthermore, it is also known from prior art that in gels of this type, a destruction or liquefaction, for example, by means of heat or mechanical pressure, is irreversible, i.e., once a gel has been destroyed, its original gel structure cannot be restored. This has been described in articles published by M. P. Kraff and J. G. Riess in Angew. Chem. 106 (1994), p. 1146, and by H. Hoffmann and G. Ebert in Angew. Chem. 100 (1988), p. 933.
[0008] In addition, the fluorine-containing gels known from prior art have an affinity both to water and to body tissues. When such gels are used over long periods of time in aqueous media or in body tissue, this affinity to water and tissue leads to a liquefaction and destruction of the gels. This, together with the fact that the gel, once destroyed, cannot have its structure restored since the destruction is irreversible prevents the long-term use of this gel as an implant in body tissue.
SUMMARY OF THE INVENTION
[0009] Thus, the problem to be solved by the present invention is to make available a plastically deformable implant which can be inserted into natural or artificially created bodily orifices of the human or animal body and which at the same time is also suitable for long-term use.
[0010] This problem is solved by the characterizing clauses of claim 1 . Useful embodiments and applications of the implant according to the present invention can be taken from the dependent claims.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0011] Because of their versatile and variable properties, the fluorine-containing gels described above are suitable for use as a starting material in the construction of a generic implant. For such an implant to be of long-term use, however, it must be ensured that the implant does not irreversibly liquefy when exposed to aqueous media. In addition, the implant must have a long-term stability to mechanical and thermal stresses. The stability of the implant material on exposure to heat must be ensured, in particular, because the material must be sterilized (121° C.) prior to inserting it into the bodily orifices. One finding on which the present invention is based relates to the fact that the gel structure of certain fluorine-containing gels is reversible and can be completely recovered even after it has been considerably damaged. Compared to the prior printed publications on fluorine-containing gels, this finding comes as a surprise.
[0012] According to the present invention, the term fluorine-containing gel is defined as a gel-like preparation which comprises a minimum of one fluorocarbon. In especially useful embodiments of the present invention, the fluorine-containing gel comprises essentially three components, i.e., a fluorocarbon, a fluorine-containing surface-active agent, and water. It is possible for different additives to be added to the fluorocarbon-containing and aqueous components. Certain compositions of surface-active agents, fluorocarbons, and water form gels which are able to completely recover their gel structure after they have been liquefied, for example, by exposure to mechanical pressure or heat. This property of the gels according to the present invention makes it possible for them to be used as a generic implant over a long period of time. If the implant material of such an implant that has been inserted into a bodily orifice were to liquefy, for example, as a result of short-term pressure, the gel structure, due to the reversibility described, would be able to recover when in a state of rest. Thus, the implant according to the present invention has a self-regulating restorative mechanism. This self-regulating restorative mechanism of a polyaphron gel is attributable to the stability of the aphrons that form the gel. After liquefaction, a gel can restore its structure only if its “building blocks,” the aphrons, were not completely destroyed. If a sufficient number of intact aphrons remain after liquefaction, a recovery is possible, and what comes as a surprise is the fact that the aphron structure is transferred to the homogenized regions of the surrounding liquid and that the gel structure is restored in the entire liquid. The stability of the aphrons depends on the intensity of the interaction between water, surface-active agent, and perfluorocarbon, which in turn is determined by the surface properties and the ability of the individual phases to spread on each other's surface. In addition, an important aspect is the intensity of the interactions of the molecules within the films that envelop the aphrons (water/surface-active agent; perfluorocarbon/surface-active agent). Thus, the self-regulating restorative mechanism is activated only if the surface properties of the surface-active agent/water and/or surface-active agent/perfluorocarbon film, on the one hand, and of the internal aphron phase, on the other hand, are properly coordinated, i.e., if the strength of the surface-active agent stabilizes the aphron structure. This can be implemented through the use of fluorine-containing surface-active agents of the general formula
R F -R pol ,
[0013] where R F stands for the linear or branched perfluoroalkyl groups with more than 5 carbon atoms and R pol stands for a polar hydrocarbon residue which comprises a minimum of one functional group which is selected from CO—NH(R), CO—N(R) 2 , COO—, COOR, SO 3 ; SO 2 N(R) 2 , CH 2 —O—R, PO 2 H, PO 3 H. The molecular weight is preferably >400 g/mol, the surface tension in aqueous solution is <30 mN/m and preferably <20 mN/m. The interfacial tension in aqueous solution with respect to the nonpolar component is <25 mN/m, preferably <10 mN/m, and the concentration is <3%, preferably <0.1%. With nonfluorinated surface-active agents, this can be achieved by means of a strong cohesive effect with an HLB value greater than 25 (HLB=hydrophilic lipophilic balance according to Griffin in J. Soc. Cosmet. Chem. 1 (1949), p. 311).
[0014] Thus, the implant according to the present invention is able to resist both thermal stress, for example, during sterilization, and mechanical stress, for example, pressure exerted on the bodily orifice. Furthermore, the ability of the implant according to the present invention to reverse the damage to its structure prevents the destruction of the implant material that is caused by diffusion processes in the bodily orifices. In the implants according to the present invention, the light transmittance of the fluorine-containing gels which in other gels is generally considerably impaired as a result of these diffusion processes remains in a dynamic equilibrium.
[0015] The biocompatibility of the implants according to the present invention is ensured since ultrapurified starting materials and very small quantities of surface-active agents (preferably <0.1%) are used. Moreover, the surface-active agents used are histocompatible, intimately bonded to the gel, and homogeneously distributed throughout the entire volume.
[0016] The implant according to the present invention is used, for example, in ophthalmology as a vitreous body replacement. For this purpose, in particular fluorine-containing gels with a high specific weight and, at the same time, a high affinity to water-soluble substances are suitable. Thus, for the first time, a tamponading material or implant with a specific weight higher than that of water and, at the same time, the capacity to absorb water-soluble ions are made available. After vitrectomy and conventional procedures of retinal surgery, the plastically deformable implant is injected into the space of the vitreous body. As a result of the absorption of water, the plastically deformable implant expands. The increase in volume caused by the absorption of water enhances the tamponade effect mediated by the highly dense fluorocarbons. At the same time, pressure builds inside the implant, and this pressure counteracts a further expansion in volume and absorption of water. The dynamic equilibrium that is established as a result is ensured by the structural reversibility of the implant material and thus makes it possible for the implant to be used for long-term applications.
[0017] An additional advantage of the implant according to the present invention when used as a vitreous body replacement is the reduction of mechanical injuries in the region of the retina. Such injuries are known to arise when pure fluorocarbons are used as vitreous body replacement materials and have been attributed to the high density of the fluorocarbons. Only recently it was discovered that the injury is not caused by the static pressure. Instead, the injuries are attributable to the fact that the impalement of heavy fluids on the retina—as it occurs, for example, when the head is moved rapidly—causes an increase in the mechanical pressure. When using fluorine-containing gels as vitreous body replacement materials, this effect can be prevented through the use of certain gels. These gels are gels with a high viscosity/density ratio of >100 mPa cm 3 /g, preferably >1000 mPa cm 3 g. Gels according to the present invention of this type make possible a tamponade in the lower eye segment without the development of motion-induced pressure peaks during sudden jerky head movements. This is made possible by the viscosity which—in comparison to that of pure fluorocarbons—is increased, and this increased viscosity counteracts the acceleration forces and prevents the damaging impact of heavy fluids on the retina. In this context, it is a particular advantage that compared to the material properties of pure fluorocarbons, those of the fluorine-containing gels are variable within wide limits.
[0018] In contrast to all other ophthalmological preparations on the basis of fluorinated compounds, the implants according to the present invention as ophthalmological preparations for application in the vitreoretinal region can be used not only in procedures that aim at the reattachment of the retina and as a short-term tamponading material. Instead, in addition to the tamponade effect, these implants can also perform other functions of the natural vitreous body. Thus, these implants open up new possibilities, such as treating pathological changes in the vitreoretinal region or suppressing morbid processes which may lead to a permanent injury to the retina, e.g., injury to the Müller cells. For this purpose, the preparations can be designed to ensure that they combine different and even opposite properties in such a way that these can be activated in one single treatment step. The application potential of the gels is enhanced and expanded by the fluorocarbons that are contained in the gels which, as is well known, have special properties, such as anti-inflammatory and anti-gas properties.
[0019] The other known properties of fluorine-containing compounds that are of advantage when such compounds are applied as ophthalmological preparations are maintained or even enhanced in the implants according to the present invention, thus, for example, the possibility of a laser treatment, the tamponade properties, and the solubility of active ingredients. The implants according to the present invention can be removed from the bodily orifices using conventional methods, for example, vitrectomy.
[0020] The fluorine-containing implants according to the present invention can also be used as intraocular lenses. For this particular purpose, it is recommended that highly transparent gels be used which have an especially high viscosity/density ratio; this can be achieved in particular through the use of oligomer R F F H compounds as the discontinuous phase, such as has been described in the European Patent No. EP-A 545 174. In addition, the refractive index of the gels used should be adjusted to a range from 1.334 to 1.338, which can be implemented, for example, by using the following compounds:
Surface-active agent Name/structure/abbreviation/ Biocompatibility Fluorocarbon characteristics Refractive index (Draize test) Perfluorophenanthrene Perfluoroalkyl ethanol 1.3357 n.d. oxethylate (Fluowet OTN, Clariant) σ O = 18 mNm, σ G = 19 mNm Perfluorophenanthrene Fluorinated amine oxide 1.3361 n.d. (Fluowet OX, Clariant) σ O = 22 mNm, σ G = 12 mNm Perfluorophenanthrene Perfluoroalkyl ethanol 1.3355 neg. oxethylate (Fluowet OTL, Clariant) σ O = 19 mNm, σ G = 10 mNm Perfluorophenanthrene Perfluorooctanoic acid 1.3362 neg. tetraethyl piperazinium salt (HO224) σ O = 16 mNm Perfluorophenanthrene Perfluorooctanoic acid 1.3360 neg. N-methyl-D-glucamide (T14) σ O < 20 mNm Perfluorophenanthrene Perfluorooctanoic acid 1.3358 neg. diethanolamide (HO31) σ O < 20 mNm Perfluorophenanthrene Tetramethyl ammonium salt of 1.336 neg. perfluorooctanoic acid (E 749) σ O < 20 mNm Perfluorophenanthrene Perfluorooctanoic acid 1.336 neg. amidotrimethyl ammonium iodide (B98) σ O < 20 mNm Perfluorophenanthrene Tetraethyl animonium salt of 1.3359 neg. perfluorooctanesulfonic acid (B248) σ O < 20 mNm Perfluorophenanthrene Perfluorodecanoic acid 1.3357 neg. N-(2-hydroxyethyl)-D- glucamide (T21) σ O < 20 mNm Perfluorophenanthrene Perfluorooctanoic acid 1.336 neg. N-(2-hydroxyethyl)-D- glucamide (T16) σ O < 20 mNm C 6 P 13 C 8 H 17 Tetramethyl ammonium salt of 1.3463 n.d. perfluorooctanoic acid (E749) σ O < 20 mNm (C 6 F 13 C 2 H 4 ) 3 Tetramethyl ammomium salt of 1.3357 n.d. perfluorooctanoic acid (E 749) σ O < 20 mNm
[0021] The implants according to the present invention can be used instead of the artificial intraocular lenses made of silicone, PMMA, or acrylic that are normally used for cataract operations. After opening the capsular sac and removing the cloudy natural lens using conventionally known methods, the implant material is injected, ensuring that the entire capsular sac is completely filled with it. The implant takes over the complete function of the natural lens, i.e., in spite of the cataract operation, the accommodative capacity of the lens is maintained. Due to the forces that are continuously acting on the implant, the mechanical long-term stability is of very special importance in this particular application.
[0022] The implants according to the present invention can also be used to temporarily seal off bodily orifices and to temporarily separate tissue parts, for example, in applications in which the implants are used as expanders, or to stimulate the growth of bone. In dentistry, the implant according to the present invention can be used in particular to temporarily fill extraction cavities in the jaw bone and to expand tissue. In addition, it can be used in orthopedic medicine as a biocompatible lubricating film for joints and joint prostheses. After inserting the implant material into the extraction cavities, these cavities are encapsulated by sewing together the surrounding tissue. This prevents leakage of the gel-like implant.
[0023] The practical examples described below will explain the choice of the implant materials and their preparation in greater detail. In the explanation, reference is made to the accompanying drawings. As can be seen, these drawings include:
[0024] [0024]FIG. 1: Measurement of pressure peaks during the acceleration of perfluorophenanthrene in a sealed glass tube, end-scale deflection corresponds to 70 mbar (52.5 mm Hg).
[0025] [0025]FIG. 2: Measurement of pressure peaks during the acceleration of an implant material according to the present invention in a sealed glass tube, end-scale deflection corresponds to 70 mbar (52.5 mm Hg).
EXAMPLE 1
[0026] Using ultrasound, a mixture of 99% fluorocarbon, 0.9% isotonic physiological saline solution, and 0.1% OTL is prepared from perfluorophenanthrene which has been ultrapurified according to a well-known method (European Patent No. EP 0 626 936 B1), isotonic physiological saline solution and Fluowet OTL (firm of Clariant); a polyaphron gel in a volume concentration of less than 30% which has been prepared according to conventional methods is slowly added to this solution until the entire mixture solidifies to form a gel. The preparation turns completely transparent after the gas is carefully removed from it or it is centrifuged.
[0027] By subjecting this implant material to alternating mechanical stresses, such as heating to approximately 130° and/or adding water, it is possible to completely liquefy the material. By adding light mechanical energy or cooling or removing water through an absorbent material (dry glass filter, etc.), the gel is returned to its original state. This procedure can be repeated several times, without changing the composition of the plastically deformable implant material.
EXAMPLE 2
[0028] A plastically deformable implant material which has been prepared according to the instructions described in Example 1 is covered with twice the quantity of water. As a result, the gel-like phase expands. When the volume is limited, e.g., by a semipermeable bottom, an increased pressure begins to build up inside the material until the water on which pressure is exerted from one side exits and flows off on the other side, without destroying the gel structure.
EXAMPLE 3
[0029] An implant material which has been prepared according to the instructions described in Example 1 and which contains T14 instead of OTL (firm of Clariant), is covered with three times the quantity of water. Instead of the original phase boundary, a thin third phase forms. By especially adjusting the diffusion rates from the boundary layer of the implant and the depth of the volume of gel, it is possible to obtain a perfluorophenanthrene barrier layer which prevents a further dilution of the gel or the breakdown of the gel. This ensures that a stability over a very long time is achieved.
EXAMPLE 4
[0030] A gel which has been prepared according to the instructions described in Example 1 is placed into a glass tube which can be sealed on both ends. A sensitive pressure sensor is coupled to one end of the glass tube. Subsequently, the glass tube is shaken and positioned so as to ensure that alternately one of the opening points downward. The same test is repeated, except that water and perfluorophenanthrene instead of the plastically deformable implant are used (FIG. 1). As a result of the viscosity/density ratio of >3000 mPa cm 3 /g, a tamponade effect appropriate to the perfluorocarbons can be achieved by the implant material, without entailing the pressure peaks observed as a result of centrifugal or shaking motions (given an incomplete filling up to 50 mm of mercury), such as are observed with pure perfluorocarbons. In ophthalmological applications, the pressure peaks must not exceed the tolerable intraocular pressure (20, for a short time, 30 mm of mercury). Thus, the plastically deformable implant has a characteristics profile that is highly suitable for use in ophthalmological applications, which profile is a prerequisite for the long-term use as a vitreous body replacement material and, at the same time, it is able to prevent mechanical injury to the retina (FIG. 2).
EXAMPLE 5
[0031] According to the method described in Example 1, it is possible to use, e.g., sodium dodecyl sulfate (SDS) HBL 40 or Pluoronic F68 (F68) HLB 29, as surface-active agents in the production of the implants according to the present invention. In both cases the fluorocarbon used is perfluorophenanthrene. The substances can be sterilized at 121° C. | The invention relates to a plastically deformable implant for inserting into bodily orifices of the human or animal body. Implants of this type are used, for example, in ophthalmology, in particular, as vitreous body or lens replacements and in dentistry, for example, for filling extraction cavities in jaw-bones. Known implants, however, are not suitable for long-term use. The invention aims to provide a deformable plastic implant which also has a long-term application. This is achieved by the fact that the implant consists of a gel which is not sealed, containing fluorocarbon and which is directly introduced into the natural, or artificially created bodily orifice. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application Ser. No. 12/963,773 entitled Methods and Apparatus for Switching a Transponder to an Active State, and Asset Management Systems Employing Same” filed Dec. 9, 2010, which is a divisional of U.S. patent application Ser. No. 11/678,296 entitled “Methods and Apparatus for Switching a Transponder to an Active State, and Asset Management Systems Employing Same” filed Feb. 23, 2007, now U.S. Pat. No. 7,876,225, which claims the benefit of U.S. Provisional Application No. 60/776,046, entitled “Methods and Apparatus for Switching a Transponder to an Active State, and Asset Management Systems Employing Same,” which was filed on Feb. 23, 2006, the disclosure of which is incorporated herein by reference.
GOVERNMENT CONTRACT
[0002] This work was supported in part by a grant from NASA under Contract No. NNK040AZ9C. The United States government may have certain rights in the invention described herein.
FIELD OF THE INVENTION
[0003] The present invention relates to transponders, such as RFID tags, and in particular to methods and apparatus for switching a transponder to an active state and asset managements system that employ such transponders.
BACKGROUND OF THE INVENTION
[0004] The use of radio frequency identification (RFID) systems is expanding rapidly in a wide range of application areas. RFID systems consist of a number of radio frequency tags or transponders (RFID tags) and one or more radio frequency readers or interrogators (RFID readers). The RFID tags include one or more integrated circuit (IC) chips, such as a complementary metal oxide semiconductor (CMOS) chip, and an antenna connected thereto for allowing the RFID tag to communicate with an RFID reader over an air interface by way of RF signals. In a typical RFID system, one or more RFID readers query the RFID tags for information stored on them, which can be, for example, identification numbers, user written data, or sensed data. RFID systems have thus been applied in many application areas to track, monitor, and manage items as they move between physical locations.
[0005] RFID tags can generally be categorized as either passive tags or active tags. Passive RFID tags do not have an internal power supply. Instead, the relatively small electrical current induced in the antenna of a passive RFID tag by the incoming RF signal from the RID reader provides enough power for the IC chip or chips in the tag to power up and transmit a response. Most passive RFID tags generate signals by backscattering the carrier signal sent from the RFID reader. Thus, the antenna of a passive RFID tag has to be designed to both collect power from the incoming RF signal and transmit (or reflect, e.g., backscatter) the outbound backscatter signal. Due to power limitations, the ability to provide devices such as sensors or microprocessors on passive RFID tags is limited. Passive RFID tags do, however, have the advantage of a near unlimited lifetime as they obtain their power from the RF signal sent from the RFID reader.
[0006] Active RFID tags, on the other hand, have their own internal power source, such as, without limitation, a battery, a fuel cell or what is commonly known as a super capacitor. The internal power source is used to power the IC chip or chips and discrete circuit elements, which typically include an RF receiver, an RF transmitter, and some type of controller, such as microcontroller or other processor, and any other electronics provided on the active RFID tag. As a result, active RFID tags can include relatively high power devices such as sensors, microprocessors, receivers and transmitters. Also, because of the on-board power, active RFID tags typically have longer ranges and larger memories than passive RFID tags. The internal power source, however, also means that active RFID tags typically have a lifetime that is limited by the lifetime of the power source. Thus, periodic maintenance is required.
[0007] As noted above, multiple active RFID tags may be used to track, monitor, and manage multiple items/assets as they move between physical locations. In such an application, each active RFID tag is affixed to an item/asset that is located in a particular location or environment, such as in a building. Building shall refer to any structure including, without limitation, a warehouse, a hospital, an office building, or even a vehicle. In current RFID systems, the active RFID tags, when deployed in such a manner, are done so in a state where (i) an RF receiver of the tag is in an active state for receiving RF signals, and (ii) the controller is in a low power inactive (sleep) state to preserve power. When one or more of the active RFID tags are to be queried, the RFID reader sends out a wake-up signal that is received by the RF receiver of each tag. Tags may also be on continuously not requiring a wake-up signal. Upon receipt of the signal, the RF receiver in each tag will then send a signal to the controller of the tag that causes it to move from the inactive state to an active (wake-up) state. For example, in RFID systems implemented according to the ISO 18000 Part 7 standard, when one or more tags are to be queried, the reader will send out a 30 KHz tone lasting for a period of approximately 2.5 seconds. Upon receipt of the tone, the RF receiver in each tag will wake-up the controller in the tag. The RFID reader then sends out signals intended for particular ones of the tags. Those particular tags for which the signals are intended will then perform the requested action, and the remaining tags (i.e., those tags not currently of interest to the reader) will move back to a sleep state.
[0008] The multiple active RFID tag arrangement just described presents at least two power management problems. First, each active RFID tag that is deployed is required to have at least one component, i.e., an RF receiver, in an active, relatively high power consuming state at all times so that it can listen for the wake-up signal. Second, when the RFID reader needs to query one or more particular tags, all of the tags that are deployed are woken up (for example, according to the ISO 18000, Part 7 standard), i.e., their controllers are caused to move to an active, relatively high power consuming state. Only when a particular tag determines that the query in question is not intended for it will it then move back to the sleep state. As will be appreciated, these problems result in unnecessary use of power from the power source (e.g., battery) of each tag, and therefore decreases the lifetime of each tag.
SUMMARY OF THE INVENTION
[0009] The present invention overcomes at least two problems associated with (1) current active RFID tags, and (2) current active RFID tag wake-up protocols. The first problem is that in current RFID tags, an active RF receiving element must always be awake to anticipate a wake-up signal for the balance of the tag electronics. The present invention uses a passive circuit to eliminate the need for an “always on” active RF receiving element to anticipate a wake-up signal for the balance of the tag electronics. This solution allows the entire active RFID tag to have all circuit elements in a sleep (standby) state, thus drastically extending battery life or other charge storage device life and thus essentially eliminating shelf maintenance on the active RFID tag. The second problem is that in current active RFID tag systems, the electronics of all of the RFID tags in a system are awakened in response to wake-up signals even if the signal is not intended for a particular tag or tags. The present solution provides a major energy saving circuit that eliminates the need to wake up all of the RFID tags in response to each wake-up signal. This circuit thus reduces total energy consumption of an active RFID tag (or sensor) system or collection of devices by allowing all non-addressed tags (sensors) to remain in a sleep (standby) state, thereby reducing total system or collection energy. This second circuit can be used in conjunction with the first passive circuit mentioned above or in conjunction with any existing active RFID tag (sensor) systems. Thus, the elements of the present invention capitalize on the benefits of an active RFID tag while eliminating the problems discussed above, thus moving active RFID tags closer to a passive tag operation.
[0010] In one embodiment, the present invention relates to a transponder apparatus, such as, without limitation, an RFID tag, that includes an electronic device, such as a processing unit (e.g., microprocessor or microcontroller), that is capable of being in an inactive, sleep state and an active state, a power source, such as a battery, in electronic communication with the electronic device for providing power to the electronic device, and a switch having an antenna for receiving at least one RF signal. The switch converts the at least one RF signal into at least one DC signal. The at least one DC signal causes the electronic device to move from the inactive, sleep state to the active state. Preferably, the switch does not require power from the power source or another power source within or connected to the transponder apparatus. The switch may, in one embodiment, include a rectifying circuit, such as a charge pump, for converting the at least one RF signal into the at least one DC signal. The switch in that embodiment may also further include a matching network electrically connected to the antenna, wherein the charge pump is electrically connected to an output of the matching network. In yet another embodiment, the transponder apparatus may further include an RF transmitter and/or an RF receiver that is/are in electronic communication with the processing unit.
[0011] In one particular embodiment, the antenna is tuned to a particular frequency or range of frequencies. In this embodiment, the at least one RF signal has a frequency that is substantially equal to the particular frequency or is within the range of frequencies.
[0012] The at least one DC signal may be provided to the electronic device to directly cause the electronic device to move from the inactive, sleep state to the active state. Alternatively, the transponder apparatus may further include a filtering circuit in electronic communication with the switch, wherein the at least one DC signal is provided to the filtering circuit. The filtering circuit provides a wake-up signal to the electronic device to cause the electronic device to move from the inactive, sleep state to the active state only if the at least one DC signal and/or the at least one RF signal has a predetermined format, such as a predetermined number of bursts each having a predetermined duration.
[0013] In another embodiment, the transponder apparatus further includes one or more additional switches that each has an additional antenna for receiving at least one additional RF signal. Each additional switch converts the at least one additional RF signal into at least one additional DC signal. The at least one RF signal and each of the at least one additional RF signals have different frequencies. In this embodiment, a logical combination of the at least one DC signal and one or more of the at least one additional DC signals causes the electronic device to move from the inactive, sleep state to the active state. Alternatively, the electronic device may be caused to move from the inactive, sleep state to the active state only if the at least one DC signal and the at least one additional DC signals are created in a particular sequence.
[0014] In another embodiment, the present invention relates to a method of moving an electronic device, such as a processing unit, included in a transponder apparatus from an inactive, sleep state to an active state, wherein the electronic device consumes power from a power source of the transponder apparatus in the active state. The method includes receiving at least one RF signal and converting the at least one RF signal into at least one DC signal without consuming power from the power source or another power source within or connected to the transponder apparatus. The method further includes providing a wake-up signal to the electronic device in response to receipt of the at least one RF signal that causes the electronic device to move from the inactive, sleep state to the active state. The wake-up signal of the method may, in one particular embodiment, be the at least one DC signal. Alternatively, the method may include determining whether the at least one DC signal or the at least one RF signal has a predetermined format, wherein the providing step comprises providing the wake-up signal (which is separate from the at least one DC signal) to the electronic device to cause the electronic device to move from the inactive, sleep state to the active state only if it is determined that the at least one DC signal or the at least one RF signal has the predetermined format. The predetermined format may include a predetermined number of bursts, each of the bursts having a predetermined duration.
[0015] In another embodiment, the method further includes receiving at least one additional RF signal and converting the at least one additional RF signal into at least one additional DC signal without requiring the consumption of power from the power source or another power source within or connected to the transponder apparatus. In this embodiment, the at least one RF signal and each of the at least one additional RF signals have different frequencies, and the providing step comprises providing the wake-up signal to the electronic device to cause the electronic device to move from the inactive, sleep state to the active state only in response to a logical combination of the at least one DC signal and one or more of the at least one additional DC signals. Alternatively, the wake-up signal may be provided to the electronic device only if the at least one DC signal and the at least one additional DC signals are created in a particular sequence and/or if the at least one RF signal and each of the at least one additional RF signals are received in a particular sequence.
[0016] Another aspect of the present invention relates to a system for tracking a plurality of assets that includes a central computer system that maintains a plurality of records relating to the assets, and a plurality of transponders, wherein each of the transponders is associated with a respective one of the assets and stores an identifier identifying the particular asset with which it is associated. Each of the transponders includes an electronic device capable of being in an inactive, sleep state and an active state, a power source in electronic communication with the electronic device for providing power to the electronic device, and a switch having an antenna for receiving at least one RF signal that is generated at the direction of the central computer system. The switch converts the at least one RF signal into at least one DC signal that causes the electronic device to move from the inactive, sleep state to the active state. When the electronic device is in the active state, the transponder generates and transmits a response signal including the identifier identifying the particular asset with which the transponder is associated. The response signal is then used to update a particular one of the records maintained by the central computer system relating to the asset identified by the identifier in the response signal. Preferably, the switch in each of the transponders does not require power from the power source of the transponder or another power source within or connected to the transponder. The transponders may be any of the various embodiments described above. As such, individual transponders or groups of transponders may be selectively awakened.
[0017] In one particular embodiment, the system further includes a network with which the central computer system may communicate, a plurality of wireless access points in electronic communication with the network, and a plurality of interface devices. Each of the interface devices is adapted to (i) wirelessly communicate with at least one of the wireless access points, (ii) receive the response signal transmitted by a particular one or more of the transponders, and (iii) generate and transmit to the at least one of the wireless access points at least one second response signal that includes each identifier that was included in each response signal received by the interface device. Each at least one second response signal is transmitted to the central computer system through the network. The central computer system uses the at least one second response signal received from one or more of the interface devices to update one or more of the records.
[0018] In another particular embodiment, the system further includes a network with which the central computer system may communicate, and a plurality of interface devices. Each of the interface devices is adapted to (i) communicate with the network, (ii) receive the response signal transmitted by a particular one or more of the transponders, and (iii) generate and transmit to the network, through a wired or wireless connection, at least one second response signal that includes at least each identifier that was included in each response signal received by the interface device. Each at least one second response signal is transmitted to the central computer system through the network, and the central computer system uses the at least one second response signal received from one or more of the interface devices to update one or more of the records.
[0019] In either of these two just described embodiments, the assets are located within an environment such as one or more building (e.g., a hospital), and each of the interface devices may be associated with a particular location within the environment. In addition, each of the second response signals may include an identification of the interface device from which it was transmitted, and the central computer system may use the identification included in each second response signal to update in the records a location of one or more of the assets.
[0020] In one particular embodiment, each of the transponders has a code associated therewith, and wherein for each of the transponders in order for the at least one RF signal received by the transponder to be converted in at least one DC signal that will cause the electronic device of the transponder to move from the inactive, sleep state to the active state, the at least one RF signal received by the transponder must be formatted according to the code associated with the transponder. In another particular embodiment, each of one or more groups of selected ones of the transponders have a code associated therewith, and wherein for each of the groups of transponders in order for the at least one RF signal received by each transponder in the group to be converted into at least one DC signal that will cause the electronic device of the transponder in the group to move from the inactive, sleep state to the active state, the at least one RF signal received by the transponder in the group must be formatted according to the code associated with the group of transponders. Thus, individual transponders or groups of transponder may be selectively awakened.
[0021] In an alternative embodiment, the present invention relates to a system for tracking a plurality of assets that includes a central computer system maintaining a plurality of records relating to the assets, a network, wherein the central computer system is in electronic communication with the network, and a plurality of interface devices each being adapted to communicate with the network. In addition, the system includes a plurality of transponders, wherein each of the transponders is associated with a respective one of the assets and stores an identifier identifying the particular asset with which it is associated. Each of the transponders is adapted to receive from one of the interface devices at least one RF signal that is generated at the direction of the central computer system and in response thereto to generate and transmit a response signal including the identifier identifying the particular asset with which the transponder is associated. Each of the interface devices is adapted to (i) receive the response signal that is transmitted by each of a particular one or more of the transponders, and (ii) generate and transmit to the network at least one second response signal that includes each identifier that was included in each response signal received by the interface device. In each case, the at least one second response signal is transmitted to the central computer system through the network, and the central computer system uses the at least one second response signal received from one or more of the interface devices to update one or more of the records. For a group the transponders, the at least one RF signal that is generated at the direction of the central computer system and that causes each of the transponders in the group to generate and transmit the response signal including the identifier identifying the particular asset with which the transponder is associated may be common to the transponders in the group.
[0022] The at least one second response signal in each case may be a plurality of second response signals, wherein each of the second response signals corresponds to a respective one of the response signals that was received by the interface device and includes the identifier that was included in the corresponding one of the response signals. The central computer system may further be adapted to cause the generation of the at least one RF signal particular to one or more of the transponders in a sequential fashion, wherein corresponding response signals and second response signals are generated and transmitted in a corresponding sequential fashion. Location information associated with each interface device may be used to update the location of each of the assets as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The accompanying drawings illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description given below, serve to explain the principles of the invention. As shown throughout the drawings, like reference numerals designate like or corresponding parts.
[0024] FIG. 1 is a block diagram of an active RF transponder according to one embodiment of the present invention;
[0025] FIG. 2 is a schematic diagram of a burst switch according to an aspect of the present invention;
[0026] FIG. 3 is a block diagram of an RF transponder according to an alternative embodiment of the present invention;
[0027] FIG. 4 is a schematic illustration of a code that may be required to awaken the transponder 50 shown in FIG. 3 ;
[0028] FIG. 5 is a block diagram of an RF transponder according to a further alternative embodiment of the present invention;
[0029] FIG. 6 is a block diagram of an alternative RF transponder that is similar to the RF transponder shown in FIG. 1 but that further includes an RF receiver;
[0030] FIG. 7 is a block diagram of an alternative RF transponder that is similar to the RF transponder shown in FIG. 3 but that further includes an RF receiver;
[0031] FIG. 8 is a block diagram of an RFID system according to an aspect of the present invention;
[0032] FIG. 9 is a block diagram of an asset management system according to a further aspect of the present invention; and
[0033] FIG. 10 is a block diagram of an interface device forming a part of the asset management system shown in FIG. 9 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] FIG. 1 is a block diagram of an RF transponder 5 according to one embodiment of the present invention. The RF transponder 5 includes a burst switch 10 , which is described in more detail in connection with FIG. 2 . The burst switch 10 is in electronic communication with a processing unit 15 , which may be, without limitation, a microprocessor, a microcontroller, or some other type of processor device. The processing unit 15 may further be another type of electronic device, such as a CMOS device or any other electronic circuit element provided on, for example, a semiconductor substrate or printed circuit board (PCB), which performs a particular function or functions. The processing unit 15 is capable of being placed into an inactive, sleep state where the current drawn by it is at a minimum. In addition, the processing unit 15 may be woken up, i.e., moved from the inactive, sleep state to an active state, upon receipt of an external input signal. An RF transmitter 20 is in electronic communication with the processing unit 15 . The RF transmitter 20 may be a separate transmitter component, or may be part of a transceiver component that is capable of both transmitting and receiving RF signals. The RF transmitter 20 is, in response to commands received from the processing unit 15 , able to transmit RF signals through an antenna 25 connected thereto. Like the processing unit 15 , the RF transmitter 20 is capable of being placed into an inactive, sleep state where the current drawn by it is at a minimum, and can be woken up by receipt of an external input signal provided by the processing unit 15 . The RF transponder 5 also includes a battery 30 which provides the power required for the operation of the processing unit 15 and the transmitter 20 . The battery 30 may alternatively be replaced by another power source, such as, without limitation, a fuel cell or a super capacitor.
[0035] FIG. 2 is a schematic diagram of the burst switch 10 . The burst switch 10 includes an antenna 35 , which, in the embodiment shown in FIG. 2 , is a square spiral antenna. The antenna 35 is electrically connected to a matching network 40 , which in turn is electrically connected to a voltage boosting and rectifying circuit preferably in the form of a charge pump 45 . Charge pumps are well known in the art. Basically, one stage of a charge pump essentially doubles the effective amplitude of an AC input voltage and stores the resulting increased DC voltage on an output capacitor. The voltage could also be stored using a rechargeable battery. Successive stages of a charge pump, if present, will essentially increase the voltage from the previous stage resulting in an increased output voltage. The matching network 40 matches the input impedance of the charge pump 45 to the impedance of the antenna 35 for optimal performance of the antenna 35 and optimal charge pump 45 output voltage. In one particular embodiment, the matching network 40 is an LC tank circuit formed by, for example, the inherent distributed inductance and inherent distributed capacitance of the conducing elements of the antenna 35 . The antenna 35 is tuned to receive RF signals having a particular frequency or range of frequencies. The RF signals that are received by the antenna 35 are provided, in the form of an AC signal, to the charge pump 45 through the matching network 40 . The charge pump 45 essentially amplifies and rectifies the received AC voltage signal and outputs the resulting DC signal. These operations are performed without requiring the consumption of power from the battery 30 or any other power source within or connected (physically) to the RF transponder 5 .
[0036] Referring again to FIG. 1 , in operation, the RF transponder 5 is deployed in a state wherein the processing unit 15 and the transmitter 20 are in the inactive, sleep state. As such, the draw on the battery 30 will be at a minimum. When it is desired to “wake-up” the RF transponder 5 , an RF signal of an appropriate frequency is transmitted to the RF transponder 5 by, for example, an RFID reader or other suitable device. The RF signal is received by the burst switch 10 , and as described above, the RF signal is used to produce a DC signal. The DC signal that is produced is provided to the sleep input (pin) of the processing unit 15 , which causes the processing unit 15 to move from the inactive, sleep state to its active state. In the active state, the processing unit 15 is able to perform any action that is required, such as waking up the RF transmitter 20 and causing it to transmit a signal that contains information such as an identifier for the RF transponder 5 . When finished (or after some predetermined period of time), the processing unit 15 can return to an inactive, sleep state until subsequently woken up as described herein. As will be appreciated, the burst switch 10 as shown in FIG. 2 is designed to produce a DC signal of an appropriate level for input into the sleep input of the processing unit 15 through appropriate selection of the parameters of the antenna 25 , the matching network 40 and/or the charge pump 45 .
[0037] A shortcoming of the RF transponder 5 shown in FIG. 1 is that spurious RF energy (noise) received by the burst switch 10 could inadvertently cause the processing unit 15 to move to the active state, thereby consuming power when not needed. Also, if a number of similar RF transponders 5 (i.e., similar meaning the antenna 35 of each is tuned to the same frequency or frequency range) are deployed together, an RF signal that is transmitted by a reader will activate all of the RF transponders 5 , even if they are not all currently of interest to the reader. In other words, there is no way to selectively activate one or more of them without also activating the remaining ones of them.
[0038] FIG. 3 is a block diagram of an RF transponder 50 according to an alternative embodiment of the present invention that addresses the shortcomings of the simple RF transponder 5 shown in FIG. 1 . As seen in FIG. 3 , the RF transponder 50 is similar to the RF transponder 5 in that it includes a burst switch 10 , a processing unit 15 , an RF transmitter 20 connected to an antenna 25 , and a battery 30 . However, the RF transponder 50 further includes a low power filtering circuit 55 . Specifically, as shown in FIG. 3 , the DC output of the burst switch 10 is provided to the filtering circuit 55 , and the output of the filtering circuit 55 is provided to the sleep input of the processing unit 15 . The function of the filtering circuit 55 is twofold. First, the filtering circuit 55 prevents spurious RF energy (noise) from inadvertently causing the processing unit 15 to move from an inactive, sleep state to an active state. Second, the filtering circuit 55 provides a mechanism by which the particular RF transponder 50 in which the filtering circuit 55 is included can be selectively woken up, i.e., have its processing unit 15 selectively moved to an active state. The filtering circuit 55 performs these functions by causing a wake-up signal to be sent to the sleep input of the processing unit 15 only if a particular sequence or pattern (i.e., format) of RF signals is received by the burst switch 10 .
[0039] In the preferred embodiment, the filtering circuit 55 is a state machine that will generate a wake-up signal only if a particular pre-set “code” is received from the burst switch 10 , wherein the code is a particular sequence of a certain number of voltage “bursts” (i.e., voltage signals of a certain (although possibly varying) length or duration; in this case, the bursts are DC signals, but bursts as used herein may also refer to RF signals of a certain (although possibly varying) length or duration) from the burst switch 10 each having a particular length expressed as a multiple of some pre-set unit of time, such as 1 millisecond. FIG. 4 shows an example of a 4 element code that may be required to be output by the burst switch 10 and received by the filtering circuit 55 in order for the filtering circuit 55 to generate a wake-up signal for waking up the processing unit 15 . In the example of FIG. 4 , the code that must be received is a 4 burst code consisting of a burst of length 5 (e.g., 5 milliseconds), followed by a burst of length 2 (e.g., 2 milliseconds), followed by a burst of length 4 (e.g., 4 milliseconds), followed by a burst of length 6 (e.g., 6 milliseconds). In effect, the code is 5 2 4 6. As will be appreciated, the code scheme of FIG. 4 is meant to be exemplary only, and any number of bursts of any possible length and any base length unit of time may be used for a particular code without departing from the scope of the invention.
[0040] In operation, the filtering circuit 55 will count (possibly on a dedicated counter) the number of separate bursts received and the length of each burst (the length of each burst may be stored in a register or any suitable memory). When the count reaches the pre-set number, e.g., 4, the registers (or memory) are checked for the proper code (i.e., has the proper sequence of burst lengths been received). If the code is determined to be correct, the filtering circuit 55 will generate a wake-up signal for the processing unit 15 . As will be appreciated, the required code may be generated by an RFID reader by generating a sequence of an appropriate number of RF bursts wherein each RF burst is of a particular time. As described in connection with FIG. 2 , each such RF burst will result in a corresponding DC voltage (DC burst) being output by the burst switch 10 having a length equal to the length of the RF burst. Thus, in order to generate the 5 2 4 6 code described above, an RF reader must output an RF burst having a length of 5 (e.g., 5 milliseconds), followed by an RF burst having a length of 2 (e.g., 2 milliseconds), followed by an RF burst having a length of 4 (e.g., 4 milliseconds), followed by an RF burst having a length of 6 (e.g., 6 milliseconds).
[0041] The filtering circuit 55 thus solves the noise problem by requiring a particular sequence of RF bursts before the processing unit 15 is awakened. The filtering circuit 55 also allows a number of RF transponders 50 to be deployed and selectively and independently awakened. In particular, each transponder 50 (or set of transponders 50 to be grouped and awakened together) that is deployed at a location can be provided with a unique code. In order for an RFID reader to wake up a particular transponder 50 (or set of grouped transponders 50 ), the RFID reader will need to generate the appropriate RF bursts. As an alternative, any particular RF transponder 50 may be provided with more than one code that would enable it to be awakened, wherein one code may be used to awaken the RF transponder 50 individually, and another code may be used to awaken it as part of a group of particular transponders 50 .
[0042] As seen in FIG. 3 , the filtering circuit 55 is connected to the battery 30 for power purposes. Preferably, the filtering circuit 55 is a device or component that may enter a low power sleep state. The filtering device 55 will remain in a sleep state until a burst is received, at which time it will move to an active state (the burst is the wake-up signal), count the burst, measure its duration, and return to sleep until the next burst is received. As a result, minimal power is consumed by the filtering circuit 55 . As will be appreciated, the filtering circuit 55 thus may be any low power electronic device that can be turned on for a short period of time, increment a counter, measure a burst length, and then go back to sleep.
[0043] FIG. 5 is a block diagram of an RF transponder 60 according to a further alternative embodiment of the present invention that includes an alternate arrangement for addressing the shortcomings of the simple RF transponder 5 shown in FIG. 1 , i.e., the noise problem and the inability to discriminate among multiple transponders. As seen in FIG. 5 , the RF transponder 60 is similar to the RF transponder 5 in that it includes a processing unit 15 , an RF transmitter 20 connected to an antenna 25 , and a battery 30 . However, the RF transponder 60 includes multiple burst switches 10 A, 10 B, 10 C, and 10 D wherein the antenna 35 of each burst switch 10 A, 10 B, 10 C, 10 D is tuned to a different frequency or range of frequencies (although only four burst switches 10 are shown, more or less than four may be employed to suit the particular needs of the application in question without departing from the scope of the present invention). In addition, as represented by passive logic combination 65 , the burst switches 10 A, 10 B, 10 C, 10 D are topologically interconnected in manner that implements a selected logical combination, such as an AND, an OR, or any other logic operation or combination of operations. It will be appreciated that each burst switch 10 A, 10 B, 10 C, 10 D will only output a DC signal if it receives an RF signal of the appropriate frequency (each referred to as a “burst switch frequency” for convenience). Thus, the passive logic combination 65 can be chosen to only provide a wake-up signal to the processing unit 15 if a particular combination of the burst switch frequencies is received. For example, the passive logic combination 65 could be implemented as an AND such that all of the burst switch frequencies must be received for a wake-up signal to be sent to the processing unit 15 . Alternatively, the passive logic combination 65 could be implemented with a series of ANDs and ORs such that any two, or any three of the burst switch frequencies or a particular two or a particular three of the burst switch frequencies must be received for a wake-up signal to be sent to the processing unit 15 .
[0044] Thus, because particular burst switch frequencies must be received to wake-up the processing unit 15 , the arrangement shown in FIG. 5 prevents spurious RF energy (noise) from inadvertently causing the processing unit 15 to move from an inactive state to an active state. In addition, the arrangement shown in FIG. 5 may also be used to provide a mechanism by which the particular RF transponder 60 in which it is included can be selectively woken up, i.e., have its processing unit 15 selectively moved to an active state. Specifically, a number of transponders 60 may be deployed with different burst switch frequencies and/or different passive logic combinations 65 such that an RFID reader can generate appropriate RF signals to selectively wake-up certain ones of the RF transponders 60 . For example, one RF transponder 60 could be deployed wherein all of the burst switch frequencies are required to wake it up, another RF transponder 60 could be deployed wherein a particular two of the burst switch frequencies are required to wake it up, another RF transponder 60 could be deployed wherein a different particular two of the burst switch frequencies are required to wake it up, another RF transponder 60 could be deployed wherein a particular three of the burst switch frequencies are required to wake it up, and so on.
[0045] In an alternative embodiment of the RF transponder 60 , instead of providing the passive logic combination 65 , the burst switches 10 A, 10 B, 10 C, and 10 D could be combined and biased with respect to one another such that the burst frequencies must be received in a particular pre-set order for a wake-up signal to be sent to the processing unit 15 . In such an arrangement, each burst switch 10 following a first one of the burst switches 10 would require the preceding burst switch 10 to be energized before it would be capable of outputting a DC signal. In this sense, the arrangement of burst switches 10 A, 10 B, 10 C, 10 D functions like an electronic combinational lock, and as such is able to prevent noise from inadvertently waking up the processing unit 15 and is able to allow the RF transponder 60 in which it is implemented to be selectively woken-up.
[0046] FIG. 6 is a block diagram of an alternative RF transponder 5 ′ that is similar to RF transponder 5 shown in FIG. 1 except that it further includes an RF receiver 70 connected to an antenna 75 . The RF receiver 70 may be caused to move from an inactive, sleep state to an active state by the burst switch 10 in order allow for further communication with the processing unit 15 via the RF receiver 70 . The communications may be according to an established standard, such as the ISO 18000 Part 7 standard. Similarly, FIG. 7 is a block diagram of an alternative RF transponder 50 ′ that is similar to RF transponder 50 shown in FIG. 3 except that it also further includes an RF receiver 70 connected to an antenna 75 . The RF receiver 70 in this embodiment may be caused to move from an inactive, sleep state to an active state by the burst switch 10 and filtering circuit 55 in the manner described elsewhere herein in order to allow for further communication with the processing unit 15 of the RF transponder 50 ′ via the RF receiver 70 . Again, the communications may be according to an established standard, such as the ISO 18000 Part 7 standard.
[0047] FIG. 8 is a block diagram of an RFID system 80 according to an aspect of the present invention. The RFID system 80 includes a plurality of RF transponders 85 deployed in a particular location, such as within a building. The RF transponders 85 may be, without limitation, any of the RF transponder embodiments described herein, such as RF transponder 5 , RF transponder 5 ′, RF transponder 50 , RF transponder 50 ′ or RF transponder 60 . The RF transponders 85 may also be an RF transponder as described in co-pending U.S. provisional application Ser. No. 60/673,715 entitled “Method and Device for Reducing Power Consumption of Active RFID Tags,” owned by the assignee of the present invention, the disclosure of which is incorporated herein by reference, or any other type of known or later developed suitable RF transponder. The RFID system 80 further includes an interrogator unit 90 which is in electronic communication with a host (central) computer system 95 . Under the control of the host computer system 95 , the interrogator unit 90 generates the RF signals (e.g., bursts) that are required to selectively awaken one or more of the RF transponders 85 in the manners described elsewhere herein. Once awakened, each RF transponder 85 may simply transmit some identifying information to the interrogator unit 90 to confirm its presence at the location, or, in those embodiments that permit (e.g., RF transponders 5 ′ and 50 ′), each RF transponder 85 may receive further communications from the interrogator unit 90 (for example, according to the ISO 18000 Part 7 standard) and respond accordingly. Thus, due to the power conserving capabilities of the RF transponder 5 , the RF transponder 5 ′, the RF transponder 50 , the RF transponder 50 ′ and the RF transponder 60 described elsewhere wherein, the RFID system 80 is able to operate with minimal power consumption and therefore an extended lifetime. In order to avoid collisions in one embodiment, the RF interrogation response signals are transmitted one at a time in a sequential manner, such as according to an order determined by the unique identifier of each RFID tag 110 . Other collision avoidance mechanisms are also possible.
[0048] FIG. 9 is a block diagram of an embodiment of an asset management system 100 according to a further aspect of the present invention. The asset management system 100 enables centralized, remote location tracking of a number of assets 105 within a particular location 115 , such as, for example and without limitation, a hospital or another environment. The assets 105 may be any type of physical item, including both movable items and items that are permanently or temporarily fixed in place. For example, in a hospital application, the assets 105 may be various types of medial equipment, such as, without limitation, a crash cart, an EKG machine, a wheel chair, a gurney, an oxygen dispenser, a staff member, or a patient. Each of the assets 105 has an RFID tag 110 physically associated therewith, preferably by physically attaching the RFID tag 110 to the asset 105 . Each RFID tag 110 is preferably any of the RF transponder embodiments described herein, such as RF transponder 5 , RF transponder 5 ′, RF transponder 50 , RF transponder 50 ′ or RF transponder 60 .
[0049] The asset management system 100 further includes a central asset management computer system 120 that is connected to a main network 125 . The asset management computer system 120 may include, without limitation, a PC or another suitable computing device that is provided with one or more software applications for implementing the system described herein. As seen in FIG. 9 , a number of wireless access points 130 are in electronic communication, preferably wired communication, with the main network 125 and are dispersed throughout the location 115 . Each wireless access point 130 is capable of receiving a signal from the main network 125 , and thus from the asset management computer system 120 , and wirelessly transmitting that signal within a particular defined area. In addition, each wireless access point 130 is capable of receiving wireless signals from within its particular defined area and transmitting those signals to the main network 125 , and thus to the asset management computer system 120 . The main network 125 and wireless access points 130 thus form a wireless network for the location 115 . In the preferred embodiment, the wireless network for the location 115 is a WiFi network that is implemented according to the IEEE 802.11 family of standards, or another suitable standard.
[0050] The asset management system 100 also further includes a number of interface devices 135 that are dispersed throughout the location 115 . Each interface device 135 is located within the range of at least one of the wireless access points 130 . As described in greater detail below, each interface device 135 is capable of receiving wireless (RF) signals from and transmitting wireless (RF) signals to the associated wireless access point 130 according to the appropriate protocol. In addition, each interface device 135 is capable of transmitting RF signals to the RF tags 110 that are in proximity thereto and receiving RF signals from those RF tags 110 . In particular, based upon control signals received from the asset management computer system 120 through the main network 125 and the appropriate wireless access point 130 , each interface device 135 is capable of transmitting one or more RF signals to the burst switch 10 of the associated RF tags 110 (in the manner or manners described elsewhere herein in connection with the embodiments of the RF transponder 5 , the RF transponder 5 ′, the RF transponder 50 , the RF transponder 50 ′ and the RF transponder 60 ) for purposes of causing the processing unit 15 of the associated RF tags 110 to move to an active state. In addition, each interface device 135 is capable of receiving response signals from the associated RF tags 110 after they have been awakened. In this respect, the interface devices 135 function like RFID readers or interrogators. For reasons that will be explained hereinafter, each interface device 135 is provided with an identifier that uniquely identifies it. Such identifiers enable the asset management computer system 120 to associate each interface device 135 with a particular location within the location 115 , such as a particular room or wing in a building. This may be done in the form of a table stored by the asset management computer system 120 . Thus, each interface 135 can be located or found to be non-functional through the asset management system 100 itself.
[0051] FIG. 10 is a block diagram of an embodiment of the interface device 135 shown in FIG. 9 . The interface device 135 includes a processing unit 140 , which may be, without limitation, a microprocessor, a microcontroller, or some other type of processor device. The processing unit 140 is electrically connected to a power interface 145 which provides power thereto. The power interface 145 is adapted to be coupled to an AC source, such as a wall outlet, in order to receive an AC voltage. The power interface 145 converts the AC voltage into a DC signal that is suitable for use by the processing unit 140 . A wireless network transceiver 150 is provided in electronic communication with the processing unit 140 . The wireless network transceiver 150 is adapted to receive wireless (RF) signals from and transmit wireless (RF) signals to one or more wireless access point 130 according to the appropriate protocol, such an 802.11 protocol, using an appropriate frequency, such as 2.45 GHz. In addition, a tag transceiver 155 is provided in electronic communication with the processing unit 140 for enabling the processing unit 140 to transmit appropriate RF signals to the associated RFID tags 110 and to receive appropriate response signals from associated RFID tags 110 . Thus, as will be appreciated, each interface device 135 functions as an interface between the two communications systems, i.e., the wireless network implemented by the wireless access points 130 and the wireless communications links to the RFID tags 110 . In an alternative embodiment, a separate (dedicated) transmitter may be provided in each interface device 135 for sending the required signals to the burst switch 10 , and the RF transceiver 155 may be used for other communication with the RFID tags 110 .
[0052] In one particular embodiment of the asset management system 100 , each of the RFID tags 110 is an RF transponder 5 (or, alternatively, an RF transponder 5 ′). The burst switch 10 of each of the RF transponders 5 has an antenna 35 that is tuned to a particular frequency or frequency range, such as 433 MHz. In this embodiment, the asset management computer system 120 stores one or more files, such as, without limitation, one or more files in a database, that include for each asset 105 an identification of the asset type (e.g., crash cart, EKG machine, etc.) and a unique identifier for the asset 105 . The unique identifier may be, without limitation, a serial number. The RFID tag 110 (i.e., transponder 5 ) associated with each asset 105 stores the unique identifier for the asset 105 . The unique identifier may be stored in a memory of the RFID tag 110 that is part of the processing unit 15 thereof or that is separate from but in electronic communication with the processing unit 15 thereof. When deployed, the processing unit 15 of each RFID tag 110 is in a sleep state, and will remain in that state until awakened as described below.
[0053] In operation, this particular embodiment of the asset management system 100 is adapted to track and maintain an inventory of each asset 105 including the particular location of each asset 105 within the location 115 . To do so, the asset management computer system 120 periodically or on demand generates an asset interrogation signal. The asset interrogation signal is sent to the main network 125 and then to each wireless access point 130 . Each wireless access point 130 then wirelessly transmits the asset interrogation signal according to the appropriate protocol, such as an 802.11 protocol. The wirelessly transmitted asset interrogation signal is received by each interface device 135 that is within the range of each wireless access point 130 . In response to receipt of the asset interrogation signal, each interface device 135 generates a second RF interrogation signal having a frequency that will be picked up by the antenna 35 of the burst switch 10 of each RFID tag 110 . As described elsewhere herein, when the burst switch 10 of each RFID tag 110 receives the second RF interrogation signal, a DC signal is generated that causes the processing unit 15 of each RFID tag 110 to move to an active state. Each such processing unit 15 is adapted to then cause an RF interrogation response signal of an appropriate frequency (e.g., 433 MHz) to be generated by the associated transmitter 20 in the RFID tag 110 . Each RF interrogation response signal includes the unique identifier stored by the RFID tag 110 that generated the RF interrogation response signal. In order to avoid collisions, the RF interrogation response signals are, in one embodiment, transmitted one at a time in a sequential manner, such as according to an order determined by the unique identifier of each RFID tag 110 . Other collision avoidance mechanisms are also possible.
[0054] The RF interrogation response signals are then received by the respective interface devices 135 (i.e., the interface device 135 that is in proximity to the RFID tag 110 that generated the RF interrogation response signal). Each interface device 135 compiles a list of RF interrogation response signals that is has received, and transmits a second interrogation response signal for the corresponding particular location 137 ( FIG. 9 ) according to the chosen protocol of the wireless network that is implemented. The second interrogation response signal generated and transmitted by each interface device 135 will include the unique identifier of the interface device 135 and the list of RF interrogation response signals complied by the interface device 135 . The second interrogation response signals are then received by the associated wireless access points 130 and transmitted to the asset management computer system 120 through the main network 125 .
[0055] Upon receipt of the second interrogation response signals, the asset management computer system 120 is able to update the location of each asset 105 in its records. In particular, each second interrogation response signal that is received will include a list of unique identifiers that, as described above, uniquely identify each asset 105 . Each second interrogation response signal will also include the identifier of the interface device 135 that sent it, thus identifying the location of that interface device 135 . As a result, the asset management computer system 120 can use this information to associate a particular location within the location 115 with each asset 105 .
[0056] As described elsewhere herein, one of the shortcomings of the RF transponders 5 and 5 ′ is that they could be inadvertently awakened by spurious RF noise. This could present a problem for the embodiment of the asset management system 100 just described as the RFID tags 110 , being RF transponders 5 or 5 ′ in that embodiment, could be caused to inadvertently send RF interrogation response signals in response to noise. This problem is addressed in an alternative embodiment of the asset management system 100 in which each of the RFID tags 110 is an RF transponder 50 (or, alternatively, an RF transponder 50 ′) that will be awakened by the same burst code, e.g., 5 2 4 6. In this particular embodiment, operation of the asset management system 100 is similar to that described above. However, in this embodiment, the second RF interrogation signal that is generated by each interface device 135 upon receipt of the asset interrogation signal from a wireless access point 130 will be an RF signal consisting of the appropriate RF bursts sufficient to cause the burst switch 10 of each RFID tag 110 to create the required burst code for the filtering circuit 55 of the RFID tag 110 . As described elsewhere herein, that code, when received by the filtering circuit 55 , will cause a wake-up signal to be generated for the associated processing unit 15 , which, in response, will wake-up and generate the appropriate RF interrogation response signal. Thus, in this embodiment, the adverse affects of noise are minimized.
[0057] A further shortcoming of the RF transponders 5 and 5 ′ is that there is no mechanism for discriminating among a number of them when deployed, i.e., there is no way to selectively cause only certain ones of them to respond. As result, the embodiment of the asset management system 100 that utilizes the RF transponder 5 or 5 ′ will be required to interrogate all of the RFID tags 110 each time an inventory update is desired, as opposed to only interrogating selected RFID tags 110 and thus selected assets 105 . As will be appreciated, while this will still gather the necessary asset location information, it will cause battery power for certain of the RFID tags 110 to be unnecessarily consumed.
[0058] Thus, according to a further aspect of the present invention, a further alternative embodiment of the asset management system 100 is provided in which selected ones and/or selected groups of the RFID tags 110 may be interrogated. In this particular embodiment, each of the RFID tags 110 is an RF transponder 50 (or, alternatively, an RF transponder 50 ′) that may be awakened by a burst code that is unique to that RFID tag 110 . For example, each individual RFID tag 110 may be assigned a unique 4 element burst code as described elsewhere herein (such as 5 2 4 6) (a 4 element burst code is merely an example, and it should be understood that the burst code may have more or less than 4 elements). As a result, each of those RFID tags 110 may be selectively, individually interrogated by the asset management computer system 120 in the manner described elsewhere herein using the appropriate burst code in order to determine the current location thereof. In addition, one or more of the RFID tags 110 may also be adapted to be awakened by a particular burst code that is common to a selected group of RFID tags 110 . In other words, certain groups of RFID tags 110 (and thus certain groups of assets 105 ) may also be assigned a second burst code that may be used to awaken each of the RFID tags 110 in the group. For example, all assets 105 of type one (e.g., crash carts, or assets on floor one of a building) may be assigned the burst code 4 2 4 3, all assets 105 of type two (e.g., EKG machines, or assets on floor two of a building) may be assigned the burst code 3 1 4 2, etc. As a result, the location of all assets 105 in a particular group, such as crash carts, can be readily determined, if desired, by the asset management system 100 using a single burst code.
[0059] As will be appreciated, in the embodiment of the asset management system 100 just described, each asset interrogation signal that is sent by the asset management computer system 120 will need to include information that identifies the particular burst code that is to be used for that interrogation. The interface devices 135 will then use that information to generate the appropriate second RF interrogation signals that are transmitted. When multiple assets 105 or specified groups thereof are to be interrogated in this manner, the asset management computer system 120 will preferably generate and transmit the appropriate asset interrogation signals in a sequential fashion in order to avoid signal collision problems (the responses will also be sent in a similar, corresponding sequential fashion). Thus, according to an aspect of the present invention, the asset management computer system 120 maintains a table or similar record that links each asset 105 with the code or codes that may be used to awaken the RFID tag 110 associated with the asset 105 . That same table or other record will also preferably separately list specified asset groups (e.g., crash cards, EKG machines, assets in a particular wing, etc.) and the common code that is assigned to each group so that such common codes may be readily accessed.
[0060] In yet a further alternative embodiment of the asset management system 100 , each of the RFID tags 110 is an RF transponder 60 that, as described elsewhere herein, is able to be awakened by a particular combination or sequence of burst switch frequencies. This embodiment is similar to the embodiment of the asset management system 100 described above that employs the RF transponders 50 or 50 ′, except that the burst codes are replaced by specified combinations or sequences of burst switch frequencies. The basic operation of the asset management system 100 otherwise remains essentially the same.
[0061] The present invention therefor provides a number of embodiments of RF transponders and assets management systems employing the same that minimize the power that is consumed by each transponder. As a result, the lifetime of each RF transponder may be maximized.
[0062] While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. For example, the majority of the description contained herein describes the burst switch 10 as awakening a processing unit 15 . It should be appreciated that the burst switch 10 may be utilized to awaken any type of electronic device that is capable of entering an inactive, sleep state. Additions, deletions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as limited by the foregoing description but is only limited by the scope of the appended claims. | A transponder that may be used as an RFID tag includes a passive circuit to eliminate the need for an “always on” active RF receiving element to anticipate a wake-up signal for the balance of the transponder electronics. This solution allows the entire active transponder to have all circuit elements in a sleep (standby) state, thus drastically extending battery life or other charge storage device life. Also, a wake-up solution that reduces total energy consumption of an active transponder system by allowing all non-addressed transponders to remain in a sleep (standby) state, thereby reducing total system or collection energy. Also, the transponder and wake-up solution are employed in an asset tracking system. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
This is a divisional of application Ser. No. 09/466,807 filed Dec. 20, 1999, now U.S. Pat. No. 6,464,950, which claims benefit of Provisional Application No. 60/163,391 filed Nov. 4, 1999; the above-noted prior applications are each hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a method for separating a reaction exhaust gas from production of carbon fiber and an apparatus used for separation of the gas, which exhaust gas is generated in a reaction furnace during production of carbon fiber, more particularly vapor-grown carbon fiber formed by thermal decomposition of an organic compound in a reducing atmosphere containing hydrogen; to a method for treating exhaust gasses and an incinerator used for treatment of the gasses, which gasses include the reaction exhaust gas and/or a thermal treatment exhaust gas generated during thermal treatment, including firing and graphitization, performed in a post-process; and to a method for producing the carbon fiber.
BACKGROUND OF THE INVENTION
Carbon fiber is produced from a variety of raw materials, and fine carbon fiber is produced through a method in which an organic compound such as methane, ethylene, benzene, or toluene is thermally decomposed at 800-1,300° C. in a thermal-decomposition furnace containing a reducing gas such as hydrogen or carbon monoxide, by use of a transition metal such as iron serving as a catalyst; i.e., a seed.
Specific examples of methods for producing carbon fiber include:
(1) a method for producing carbon fiber in which super-fine powder of a transition metal is distributed on a substrate in a thermal-decomposition furnace and used as seeds (Japanese Patent Application Laid-Open (kokai) No. 103528/1977);
(2) a method for producing carbon fiber in which a transition metal compound such as ferrocene is vaporized and introduced into a thermal-decomposition furnace to thereby form super-fine powder of a transition metal, and the powder is used as seeds (Japanese Patent Application Laid-Open (kokai) No. 54998/1985);
(3) a method for producing carbon fiber in which a transition metal such as iron is directly vaporized in a thermal-decomposition furnace to thereby form super-fine powder, and the powder is used as seeds (Japanese Patent Application Laid-Open (kokai) No. 29 1497/1986); and
(4) a method for producing carbon fiber in which a transition metal compound such as ferrocene is diffused or dissolved in an organic compound serving as a raw material, and the resultant mixture is introduced into a thermal-decomposition furnace to thereby form super-fine powder of a transition metal, and the powder is used as seeds (Japanese Patent Application Laid-Open (kokai) No. 180615/1983).
Japanese Patent No. 2778434 discloses a method for producing carbon fiber, in which an organic compound containing a transition metal such as iron, serving as a catalyst, is dissolved in a raw material liquid such as benzene, and the resultant solution is sprayed on the inner wall of a reaction furnace heated at 800-1,300° C., to thereby thermally decompose the material. Specifically, a transition metal compound such as ferrocene, serving as a catalyst, is dissolved in a liquid organic compound such as benzene, and the resultant solution is sprayed on the inner wall of a reaction tube, serving as a thermal-decomposition furnace, by use of hydrogen serving as a carrier gas, to thereby form seeds and thermally decompose the organic compound. As a result, crude carbon fiber of fine fibrous shape is produced. (Hereinafter the above process will be referred to as “the first process.”)
The thus-produced carbon fiber or the reaction furnace contains flammable gases including a carrier gas such as hydrogen, and hydrocarbon generated in a side reaction (hereinafter the flammable gases will be collectively referred to as “reaction exhaust gas”), and thus the gas must be separated. A reaction exhaust gas which is separated from carbon fiber in a reaction furnace is collected with relative ease, but a reaction exhaust gas contained in carbon fiber, or in other words, captured between filaments of the carbon fiber, is difficult to separate.
Conventionally, a reaction exhaust gas is separated from carbon fiber containing the reaction exhaust gas by means of the following methods: (1) a method in which the temperature of a thermal-decomposition furnace is lowered after completion of reaction, and the inside of the furnace is substituted by nitrogen gas, to thereby separate the reaction exhaust gas; and (2) a method in which a recovery can is provided in a lower portion of a thermal-decomposition furnace, and carbon fiber containing a reaction exhaust gas is recovered in the can and the inside of the can is substituted by nitrogen gas, to thereby separate the exhaust gas.
However, when carbon fiber is industrially produced, in the above method (1), reaction or recovery is carried out batchwise, which is disadvantageous in terms of efficiency. In addition, the temperature of a thermal-decomposition furnace must be lowered, which is unsatisfactory in consideration of energy efficiency.
In the above method (2), a large recovery tube is required, due to low bulk density of carbon fiber, which results in high cost.
In the methods (1) and (2), the produced carbon fiber has a very low bulk density of 0.001-0.005 g/cm 3 as measured immediately after production, which means a large volume of space between fibers. Thus, gas held in such space cannot be completely removed from the carbon fiber, and may directly accompany the fiber product.
In addition, the carbon fiber is detrimentally difficult to handle due to its low bulk density.
A recovered reaction exhaust gas is flammable and explosive, since the gas predominantly contains hydrogen. Therefore, conventionally, the gas is diluted in a blower in order to reduce the concentration of hydrogen below the range causing explosion, and then released in the air.
The crude carbon fiber produced in the reaction tube in the first process is usually scraped off and collected. The collected carbon fiber contains non-reacted organic substances, non-fibrous carbides, and tar, and therefore, in the next process the carbon fiber is thermally treated in a non-oxidative atmosphere. For example, the carbon fiber is subjected to thermal treatment such as firing and graphitization in a closed furnace as disclosed in Japanese Patent Application Laid-Open (kokai) No. 60444/1996, in a non-oxidative atmosphere of nitrogen, helium, or argon at a temperature which varies depending on required properties of a final product. (Hereinafter the above process will be referred to as “the second process.”)
An exhaust gas generated in the second process predominantly contains inert gasses such as argon and nitrogen. In addition, the exhaust gas contains naphthalene, anthracene, and high-molecular weight substances such as tar, and thus the gas is difficult to combust. (Hereinafter the gas will be referred to as “thermal treatment exhaust gas.”)
Since the thermal treatment exhaust gas is difficult to combust, there was no other way than releasing it as is.
The present invention contemplates provision of a method and apparatus for continuously separating a reaction exhaust gas from carbon fiber with ease and in a safe manner, which exhaust gas is generated in the first process during production of carbon fiber through the above-described vapor-growth method, as well as a method and apparatus for combusting and air-releasing exhaust gasses at low cost, which gasses include the flammable reaction exhaust gas and a thermal treatment exhaust gas which is generated during thermal treatment in the second process and is difficult to combust.
The present invention also contemplates provision of a method for producing carbon fiber, including the above methods and apparatus.
Particularly, exposure of an operator to an organic compound such as benzene is regulated by the Law on Industrial Safety and Hygiene. In addition, such an organic compound is poisonous, and thus must be prevented from being released in the air. Meanwhile, hydrogen, methane, and ethylene are flammable substances, and leakage thereof may cause explosion.
Tar is difficult to collect, because of its high viscosity. A method for condensing tar by use of activated carbon or for causing tar to be adsorbed by activated carbon requires large-scale handling equipment, and tar poses problems in relation to waste treatment.
Moreover, in consideration of hygiene, tar must be handled carefully. Tar is preferably incinerated for disposal, but tar per se cannot be incinerated, since it is a high-molecular weight substance and contains inert gasses.
In order to solve these problems, the present inventors have studied a method for combusting a reaction exhaust gas. However, a reaction in the first process needs to be terminated in order to carry out equipment maintenance, and at such times only the second process may be carried out. In thermal treatment in the second process, the rate of generation of a thermal treatment exhaust gas is not constant, since the amount of carbon fiber varies. Therefore, by means of only a method for combusting such exhaust gasses, stable incineration is not carried out, and backfire to a reactor and a thermal treatment apparatus occurs, permitting damage to, for example, the apparatus. In addition, when fire is caused to be extinguished for some reason, a combustion apparatus may be filled with a reaction exhaust gas of high concentration, which provides a problem at re-ignition.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a series of processes for producing fine carbon fiber. Namely, the present invention provides a method for producing carbon fiber comprising: thermally decomposing an organic compound in a thermal-decomposition furnace at 800-1,300° C. in an atmosphere containing a reducing gas, by use of a transition metal or a compound thereof serving as a catalyst, to thereby obtain fine carbon fiber; separating a reaction exhaust gas contained in the carbon fiber from the carbon fiber; continuously subjecting the carbon fiber to thermal treatment such as firing or graphitization in a non-oxidative atmosphere; and incinerating a thermal treatment exhaust gas generated during the thermal treatment, and/or the separated reaction exhaust gas.
The present invention also provides a method and apparatus for treating exhaust gasses, which gasses include an unwanted exhaust gas which is generated during a process for producing carbon fiber and an exhaust gas generated during thermal treatment such as firing or graphitization in the second process.
Specifically, such a method and apparatus for treating exhaust gasses according to the present invention contemplate a first method and apparatus for industrially separating a flammable exhaust gas from carbon fiber predominantly containing the gas, in a safe and continuous manner, and a second method and apparatus for incinerating in a dedicated incinerator the separated reaction exhaust gas and a thermal treatment exhaust gas from the second process, such that the gasses are incinerated independently or in combination. According to the first method; i.e., a method for industrially separating a flammable exhaust gas from carbon fiber during production of carbon fiber, a packed layer of carbon fiber is formed, the carbon fiber being produced at an outlet side of a reaction furnace of vapor-grown carbon fiber in the first process; an inert gas is caused to flow upward from the lower side of the packed layer; and the packed layer is compressed. According to the first apparatus used for separating the exhaust gas from vapor-grown carbon fiber, there are provided, as shown in FIG. 1, a separation tank 1 in which a packed layer of vapor-grown carbon fiber is formed; a compression chamber 3 provided at the lower portion of the tank, the chamber comprising a compression cylinder 2 and an inert gas inlet 7 ; and a shut-off valve 4 which enables switching between compression and exhaust.
According to the second method; i.e., a method for incinerating in a dedicated incinerator the separated reaction exhaust gas and a thermal treatment exhaust gas from the second process, there are provided the following:
(1) a method for treating an exhaust gas comprising incinerating an exhaust gas generated in the production process of vapor-grown carbon fiber (hereinafter referred to as “exhaust gas of vapor-grown carbon fiber”) of vapor-grown carbon fiber in a dedicated incinerator; and
(2) a method for treating an exhaust gas comprising mixing exhaust gasses; i.e., a flammable reaction exhaust gas and a thermal treatment exhaust gas which is difficult to combust and which is generated during firing or graphitization, and incinerating the gasses simultaneously, or incinerating either of the gasses in the incinerator. The above methods (1) and (2) are further defined as follows:
(3) a method for treating an exhaust gas of vapor-grown carbon fiber, in which the gas is combusted after being ignited by a flame of a pilot burner which is maintained by use of a flammable gas. In consideration of safety, the second method is preferably drawn to:
(4) a method for treating an exhaust gas of vapor-grown carbon fiber, in which a reaction exhaust gas in a reaction exhaust gas supply pipe is purged into the incinerator and incinerated upon completion of thermal reaction of vapor-grown carbon fiber, or in which a thermal treatment exhaust gas in a thermal treatment exhaust gas supply pipe is purged into the incinerator and incinerated upon completion of thermal treatment of the fiber;
(5) a method for treating an exhaust gas of vapor-grown carbon fiber, in which backfire-preventing apparatuses are provided in the supply pipes of a reaction exhaust gas and a thermal treatment exhaust gas leading into the incinerator, so as to enhance safety of a production apparatus; and
(6) a method for treating an exhaust gas of vapor-grown carbon fiber, in which flames of the pilot burner and a primary burner are monitored at all times, and when the flames are caused to be extinguished, supply of a reaction exhaust gas is switched to a release-to-air pipe, to thereby stop supply of the exhaust gases into the incinerator and enhance safety of the incinerator.
In order to attain any one of the above-described methods (1) through (6), the following incinerator is provided:
(7) an incinerator for processing an exhaust gas of vapor-grown carbon fiber, which comprises a primary burner for supplying a reaction exhaust gas, an auxiliary burner for supplying a thermal treatment exhaust gas, and a pilot burner for igniting the exhaust gasses by use of a flammable gas.
As used herein, the term “carbon fiber” refers to annual-ring-form carbon fiber of multi-layer structure having a diameter of 0.01-5 μm, which fiber is vapor-grown in a thermal reaction furnace according to the first and second method for treating an exhaust gas.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional schematic representation showing an embodiment of a reaction exhaust gas separating apparatus of the present invention.
FIG. 2 is a cross-sectional schematic representation showing a compression process of carbon fiber in a reaction exhaust gas separating apparatus of the present invention.
FIG. 3 is a cross-sectional schematic representation showing an extrusion-recovery process of carbon fiber in a reaction exhaust gas separating apparatus of the present invention.
FIG. 4 is a cross-sectional schematic representation showing an embodiment of an incinerator of the present invention, which is used for incinerating a reaction exhaust gas and a thermal treatment exhaust gas.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will next be described in more detail.
A separation tank is provided at the outlet side of a reaction furnace, and carbon fiber is collected in the tank to thereby form a packed layer of carbon fiber.
The height of the layer is preferably 200 mm or more. When the height is less than 200 mm, the layer tends to be contaminated with gas. The bulk density of the layer preferably falls within a range of 0.005-0.05 g/cm 3 inclusive.
When the bulk density is less than 0.005 g/cm 3 , resistance of the layer becomes low and the layer tends to be contaminated with gas. In contrast, when the bulk density is more than 0.05 g/cm 3 , purge gas encounters difficulty in flowing through the layer uniformly, and thus gas in the layer is insufficiently substituted by the purge gas. The bulk density of carbon fiber can be regulated by controlling reaction conditions of carbon fiber or by compaction during conveyance of carbon fiber from a reaction furnace to a separation tank.
Purge gas used in the present invention may be any inert gas, such as nitrogen gas or argon gas. Purge gas is caused to flow from one side to the other side of a packed layer of carbon fiber. In most cases, the produced carbon fiber contains gas which is lighter than air, and thus purge gas is preferably caused to flow from the lower side to the upper side of the layer.
Purge gas is preferably introduced into a packed layer of carbon fiber from the lower side at a linear velocity of 0.5 cm/second or more. When the linear velocity is less than 0.5 cm/second, the layer may be contaminated with gas.
In addition, in order to remove gas present between the filaments of carbon fiber and increase the bulk density of carbon fiber, a packed layer of carbon fiber is compressed.
A packed layer of carbon fiber is preferably compressed so as to have a volume which is about ½ or less that before compression. Subsequently, a shut-off valve is opened and the compressed layer is intermittently removed through the valve. Alternatively, the compressed layer of carbon fiber may be continuously removed without use of a shut-off valve, by extrusion through an outlet having a squeezed head portion.
When a packed layer of carbon fiber is compressed so as to have a volume which is in excess of ½ that before compression, the layer has a large volume of interfiber space. Thus, when the layer is continuously removed, gas in the layer cannot be separated sufficiently, permitting gas to accompany the carbon fiber product.
Specifically, a pressure for compression is 0.1 kg/cm 2 or more, preferably 1.0 kg/cm 2 or more. When the pressure is less than 0.1 kg/cm 2 , gas held between filaments of the carbon fiber is insufficiently separated. The pressure may be higher, preferably to the extent that carbon fiber does not collapse. When the pressure becomes higher, facility cost of the pressurizing system becomes higher. Therefore, the pressure preferably falls within a range of 0.1-100 kg/cm 2 , more preferably 1-100 kg/cm 2 , still more preferably 1-50 kg/cm 2 .
The process by use of purge gas may be carried out prior to the compression process, or vice versa. Alternatively, these processes may be repeated alternately. However, in consideration of time and efficiency, the process making use of purge is carried out prior to the compression process, to thereby enhance effects. A compressed carbon fiber obtained through these processes is preferable in consideration of easy handling to the next process.
The present invention will be described in more detail with reference to FIGS. 1, 2 , 3 , and 4 , which description should not be construed as limiting the invention thereto.
In FIGS. 1, 2 , and 3 , reference numeral 1 represents a separation tank, 2 represents a compression cylinder, 3 represents a compression chamber, 4 represents a shut-off valve, 5 represents a recovery vessel, 6 represents an outlet of an apparatus for producing carbon fiber (and an inlet of separation tank 1 ; the apparatus for producing carbon fiber is not shown in the figures.), 7 represents an inert gas inlet, 8 represents an inert gas outlet, and 9 represents the height of a packed layer of carbon fiber.
Gas-containing carbon fiber which is produced in a reaction furnace (not shown in the Figs.) is conveyed to the separation tank 1 through the outlet 6 , to thereby form a packed layer of the carbon fiber in the tank 1 .
In this case, the height of the layer 9 is maintained at 200 mm or more. As described above, when the height is less than 200 mm, the layer tends to be contaminated with gas.
Subsequently, nitrogen gas is introduced through the inert gas inlet 7 provided in the compression chamber 3 at the lower side of the packed layer, to thereby purge gas contained in the layer. The inlet(s) may be provided in a quantity according to the size or height of a packed layer of carbon fiber.
Next, as shown in FIG. 2, the carbon fiber is compressed by use of the compression cylinder 2 so as to have a volume which is ½ or less that before compression. The pressure for compression preferably falls within a range of 0.1-100 kg/cm 2 . The carbon fiber may be removed without use of the shut-off valve 4 , by extrusion through an outlet having a squeezed head portion.
As shown in FIG. 3, the shut-off valve 4 is opened, and the thus-compressed carbon fiber is recovered in the recovery vessel 5 . Alternatively, the carbon fiber is recovered in the vessel 5 by extrusion without use of the shut-off valve 4 , through an outlet having a squeezed head portion.
When the recovery vessel 5 is filled with the carbon fiber, the vessel is replaced by a new one, to thereby continuously carry out separation of gas from carbon fiber.
In a method for treating a reaction exhaust gas and/or a thermal treatment exhaust gas of vapor-grown carbon fiber according to the present invention, as shown in FIG. 4, a vertical incinerator 18 is employed, a flammable gas is continuously combusted in the incinerator 18 by use of a pilot burner 11 , and a reaction exhaust gas is supplied through a primary burner 12 into the incinerator and ignited by use of a flame of the pilot burner 11 , to thereby incinerate the exhaust gas.
A flammable gas may be any of commercially available gasses, such as propane gas or city gas.
A reaction exhaust gas in the present invention is usually flammable and capable of being incinerated. However, in the case of incineration of the gas, since the reaction exhaust gas is flammable, the following must be carefully considered: a method for igniting the reaction exhaust gas when the gas is generated after initiation of reaction; change in pressure of the reaction exhaust gas during reaction; and occurrence of backfire when generation of the reaction exhaust gas stops after completion of reaction.
Therefore, in a method for igniting a reaction exhaust gas, the pilot burner 11 is turned on at all times in the incinerator 18 such that a reaction exhaust gas is ignited immediately after supply of the gas. The reaction exhaust gas is supplied through a reaction exhaust gas supply pipe 19 and the primary burner 12 , which comprises a nozzle portion for providing the gas with resistance, and thus backfire does not occur even when changes in pressure occur.
When supply of a reaction exhaust gas is terminated after completion of reaction, a reaction exhaust gas in the reaction exhaust gas supply pipe 19 is purged into the incinerator 18 by use of an incombustible gas, and the remaining reaction exhaust gas in a reaction system and the supply pipe 19 is incinerated, to thereby prevent backfire into the supply pipe 19 .
Flame of the pilot burner 11 and a combustion flame of a reaction exhaust gas of the primary burner 12 are monitored through the flame detector 13 at all times in the incinerator 18 . When the flames are caused to be extinguished for some reason, the reaction exhaust gas cannot be ignited, and thus the reaction exhaust gas is supplied not to the incinerator 18 but to a release-to-air pipe 21 , and supply of the exhaust gas to the incinerator 18 is terminated. In addition, the reaction is immediately terminated and the reaction exhaust gas is purged by use of an incombustible gas.
A checking apparatus such as a flame arrester or a water sealing apparatus may be provided in the supply pipe 19 of a reaction exhaust gas into the incinerator 18 .
Furthermore, sequence control may be performed so as to regulate a reaction in which a flammable reaction exhaust gas is generated, such that the reaction proceeds only when the pilot burner 11 in the incinerator 18 is turned on.
The present invention is characterized in that a supply pipe 20 and a release-to-air pipe 22 of a thermal treatment exhaust gas which is difficult to combust is independently provided and the exhaust gas is supplied to the incinerator through an auxiliary burner 15 . Accordingly, hydrogen, organic compounds, such as methane and ethylene, which have relatively high volatility and high flammability, and tar and the like, which have high viscosity at ambient temperature and are relatively difficult to combust, are combusted simultaneously. As a result, the mixture gas enables combustion of the thermal treatment exhaust gas, and combustion efficiency is enhanced.
The above-described ignition method, the backfire-preventing method, the purge method, and the treatment when fire is caused to be extinguished in a reaction exhaust gas are applicable to a thermal treatment exhaust gas.
Even when supply of a reaction exhaust gas is terminated, since a flammable gas is used as a fuel, only a thermal treatment exhaust gas can be supplied to the incinerator and combusted efficiently. In addition, the pilot burner 11 in the incinerator is turned on at all times, and thus a reaction exhaust gas and a thermal treatment exhaust gas can be stably combusted regardless of change in amount thereof.
EXAMPLES
Example 1
In a vertical reaction furnace, a benzene raw-material solution containing 4 wt. % ferrocene as dissolved therein was sprayed onto the inner wall of a reaction tube through a two-fluid spray nozzle by use of hydrogen gas serving as a carrier gas, to thereby grow carbon fiber. The flow rate of hydrogen gas was 100 L/minute and the temperature of the inner wall was 1,200° C. The carbon fiber grown on the inner wall was scraped off, to thereby obtain crude carbon fiber. The crude carbon fiber was collected in a separation tank 1 shown in FIG. 1 .
When the height of a packed layer of the collected carbon fiber in the tank 1 became 200 mm, nitrogen gas was caused to flow through an inert gas inlet 7 at a rate of 50 L/minute. When the height of the layer in the tank 1 became 500 mm or more, a compression cylinder 2 was operated, and the vapor-grown carbon fiber was compressed so as to have a volume which was ½ that before compression. In this case, the pressure for compression was 1 kg/cm 2 .
The bulk density of the packed layer before compression was 0.01 g/cm 3 .
Subsequently, a shut-off valve 4 was opened, and the compression cylinder 2 was re-operated to thereby discharge the compressed carbon fiber into a recovery vessel 5 . Thereafter, the cylinder 2 was moved to its original position, and the valve 4 was closed.
While the reaction of carbon fiber was carried out, the above-described procedures was repeated, to thereby recover carbon fiber in the recovery vessel.
During recovery of carbon fiber, hydrogen in the recovery vessel was analyzed through a hole for sampling, by use of a hydrogen detector (model: GP-226, product of Riken Keiki), but hydrogen was not detected. Methane gas and ethylene gas, which are generated during the reaction of carbon fiber, were analyzed through gas chromatography but not detected.
The recovered carbon fiber in the recovery vessel had a diameter of 0.06 μm and a bulk density of 0.02 g/cm 3 .
Example 2
The carbon fiber obtained in Example 1 was subjected to compression molding, and thermally treated under flow of argon in a continuous thermal treating furnace as disclosed in Japanese Patent Application Laid-Open (kokai) No. 60444/1996. The molded product was heated in the furnace at 1,400° C. for approximately 30 minutes.
A reaction exhaust gas generated in the process of Example 1 was supplied through a primary burner 12 at a rate of approximately 130 L/minute, and a thermal treatment exhaust gas generated in the above thermal treatment was supplied through an auxiliary burner 15 at a rate of approximately 30 L/minute. The reaction exhaust gas contained hydrogen in an amount of approximately 75%, benzene serving as a raw material; i.e., a carbon source, and organic compounds which had been by-produced. The thermal treatment exhaust gas contained argon as a primary component, and tar.
Before the reaction in the reaction furnace and before the thermal treatment in the thermal treatment furnace, the system was purged by use of nitrogen gas, and combustion was initiated. The reaction exhaust gas was supplied through the primary burner 12 to an incinerator 18 in which LPG serving as a fuel was combusted by use of a pilot burner 11 , and the exhaust gas was combusted and incinerated. Simultaneously, the thermal treatment exhaust gas was supplied through the auxiliary burner 15 and combusted. The thus-incinerated waste gas, which was sampled from the waste gas sampling hole 14 , contained benzene in an amount of 0.25 ppm or less, which represents the detection threshold.
After completion of the first process, a reaction vessel system was purged by use of nitrogen gas and the reaction exhaust gas was removed, and a primary valve was closed.
After completion of all the above processes, the continuous furnace system was purged by use of nitrogen gas, the thermal treatment exhaust gas was purged by use of nitrogen gas, and a flame of the primary burner 12 was extinguished.
In a method for treating an exhaust gas of vapor-grown carbon fiber of the present invention, a reaction exhaust gas containing methane, ethylene, and a flammable carrier gas such as hydrogen which is contained in carbon fiber during production thereof can be continuously separated with safety. In addition, the reaction exhaust gas and a thermal treatment exhaust gas generated in a thermal treatment process which is difficult to combust are completely combusted with safety. | A method for producing carbon fiber including the following processes: a process for obtaining fine carbon fiber by thermally decomposing an organic compound in a furnace by use of a catalyst; a process for separating a reaction exhaust gas contained in the carbon fiber; a process for continuously subjecting the carbon fiber to thermal treatment in a non-oxidative atmosphere; and a process for incinerating a thermal treatment exhaust gas generated in the thermal treatment and/or the reaction exhaust gas. The method for separating a reaction exhaust gas from carbon fiber is characterized in that a packed carbon fiber layer is formed, an inert gas is caused to flow through the layer, and the layer is compressed. Combustion of the reaction exhaust gas and combustion of the exhaust gas generated from the subsequent thermal treatment is achieved through employment of a pilot burner holding flame at all times in a vertical incinerator. | 3 |
RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. 119 to U.S. Provisional Application Ser. No. 62/100,719 filed Jan. 7, 2015, entitled “POWER CONTROL UNIT WITH REMOTE SENSOR,” the entire contents of which are hereby incorporated by reference for all purposes.
BACKGROUND
[0002] The present invention generally relates to means for controlling the electrical power provided to various appliances and equipment based on readings and/or control signals from remote sensors.
SUMMARY
[0003] According to first aspects of the invention, an electrical control system may include a sensor unit with an attachment mechanism for mounting the sensor unit to a fluid pipe, a fluid flow sensor, and a signal generator configured to generate a signal indicating at least one of whether the flow sensor detects a fluid flow in the fluid pipe or whether the flow sensor detects no fluid flow in the fluid pipe. The system may also include a control unit having one or more of an electrical plug, an electrical socket, an interruptible circuit between the electrical plug and the electrical socket, a receiving device configured to receive the signal from the sensor unit, and a processor configured to interrupt the circuit between the electrical plug and the electrical socket based on at least one of receipt of the signal or interruption of the signal.
[0004] In embodiments, the fluid flow sensor may include a plurality of permanent magnets and an induction coil.
[0005] In embodiments, the attachment mechanism may include a flange integrally attached to the sensor unit, a gasket and a plurality of clamps configured to fit around the pipe.
[0006] In embodiments, the sensor unit may be configured to transmit the signal via at least one of a wire connected to the sensor unit or via a wireless communication channel.
[0007] In embodiments, the control unit may be further configured to send a signal to a remote device when the circuit is interrupted by the control unit.
[0008] According to further aspects of the invention, an electrical control system may include a sensor unit with a sensor and a signal generator configured to generate a signal based at least in part on readings of the sensor. Systems may also include a control unit having one or more of an electrical input, an electrical output, an interruptible circuit between the electrical input and the electrical outlet, a receiving device configured to receive the signal from the sensor unit, and a mechanism configured to interrupt the circuit between the electrical input and the electrical outlet based on at least one of receipt of the signal or interruption of the signal.
[0009] In embodiments, the sensor may include at least one of a flow sensor, a current sensor, a pH sensor, a pressure sensor, and/or a vacuum sensor.
[0010] In embodiments, the sensor and the control unit may be configured to communicate via a wireless network.
[0011] In embodiments, the electrical input may include a standard electrical plug, such as a Type A or Type B connector, and the electrical outlet may include a corresponding standard electrical receptacle.
[0012] In embodiments, the control unit may be further configured to send a signal to a remote device when the circuit is interrupted by the control unit.
[0013] According to further aspects of the invention, a control unit may be provided including an electrical plug, an electrical receptacle, an interruptible circuit between the electrical plug and the electrical receptacle, a receiving device configured to receive the signal from a remote sensor unit, and/or a processor configured to interrupt the circuit between the electrical plug and the electrical receptacle based on at least one of receipt of the signal or interruption of the signal.
[0014] In embodiments, the remote sensor may include at least one of a flow sensor, a current sensor, a pH sensor, a pressure sensor, and/or a vacuum sensor.
[0015] In embodiments, the control unit may be configured to communicate with the remote sensor via a wireless network.
[0016] In embodiments, the electrical input may include a standard electrical plug, such as a Type A or Type B connector, and the electrical outlet may include a corresponding standard electrical receptacle.
[0017] In embodiments, the control unit may be further configured to send a signal to a remote device when the circuit is interrupted by the control unit.
[0018] According to further aspects of the invention, a sensor unit may be provided including one or more of an attachment mechanism, e.g. for mounting the sensor unit to a fluid pipe, a sensor configured to contact fluid in the pipe when the sensor unit is mounted to the pipe, and a signal generator configured to generate a signal based at least in part on readings of the sensor. In some examples, the sensor may include at least one of a flow sensor, a current sensor, a pH sensor, a pressure sensor, and/or a vacuum sensor.
[0019] In embodiments, the sensor may include at least a flow sensor, and the signal may indicate at least one of whether the flow sensor detects a fluid flow in the pipe or whether the flow sensor detects no fluid flow in the pipe.
[0020] In embodiments, the sensor unit may be configured to communicate with a control unit via a wireless network.
[0021] In embodiments, the sensor unit may be configured to mount to the pipe via a circular hole drilled in the pipe.
[0022] In embodiments, the sensor unit may include a charger electrically connected to at least one of a battery or a capacitor.
[0023] In embodiments, the sensor unit may be at least partially user programmable, e.g. to set parameters by which the signal is generated or interrupted.
[0024] Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention claimed. The detailed description and the specific examples, however, indicate only preferred embodiments of the invention. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the detailed description serve to explain the principles of the related technology. No attempt is made to show structural details of technology in more detail than may be necessary for a fundamental understanding of the invention and various ways in which it may be practiced. In the drawings:
[0026] FIG. 1 is a schematic diagram of a flow sensor and control arrangement according to aspects of the invention.
[0027] FIG. 2 is a schematic diagram of a flow sensor arrangement according to aspects of the invention.
[0028] FIG. 3 is a schematic diagram of an electrical current sensor arrangement according to aspects of the invention.
[0029] FIG. 4 is a schematic diagram of a pressure/vacuum sensor according to aspects of the invention.
[0030] FIG. 5 is a schematic diagram of a control unit according to aspects of the invention.
[0031] FIGS. 6 and 7 are side views of a control unit according to aspects of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0032] It is understood that the invention is not limited to the particular methodology, protocols, etc., described herein, as these may vary as the skilled artisan will recognize. It is also to be understood that the terminology used herein is used for the purpose of describing particular embodiments only, and is not intended to limit the scope of the invention. It also is to be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include the plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to “a sensor” is a reference to one or more sensors and equivalents thereof known to those skilled in the art.
[0033] Unless defined otherwise, all technical terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which the invention pertains. The embodiments of the invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure the embodiments of the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those of skill in the art to practice the embodiments of the invention. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the invention, which is defined solely by the appended claims and applicable law.
[0034] FIG. 1 is a schematic diagram showing an exemplary layout including a sensor and control unit system according to aspects of the invention. In the example shown in FIG. 1 , a pipe 110 may be, for example, a water pipe connected to a swimming pool. However, it should be appreciated that the example shown in FIG. 1 , and other examples described herein, is only one implementation, among many, in which aspects of the invention may be used. A sensor 120 is connected to pipe 110 such that flow or other characteristics/conditions inside of the pipe 110 may be monitored. Sensor 120 is also configured to communicate with a control unit 130 . The communication may be performed, for example, using communication wires, power wires, or by various wireless technologies, such as Bluetooth, WiFi, LAN, WAN or other means. In some examples, control unit 130 may be configured to plug into an electrical outlet, and to have power cords from one or more other devices plugged into the control unit. These may include, for example, standard 2 or 3 prong household outlets and plugs, industrial and multiphase outlets and corresponding plugs, hard-wired points, etc. The control unit 130 , in a basic form, acts as a power bridge between a power outlet and a device that is plugged into the control unit. In the example shown in FIG. 1 , a device 140 is plugged into control unit 130 and relies on control unit 130 to provide electrical power from an outlet to the device. The device 140 may be, for example, a pump connected to chemical tank 150 that adds chemicals to the water supply flowing in pipe 110 , or any other type of device that may be advantageously disabled under certain conditions sensed by sensor 120 .
[0035] Some examples of how the system in FIG. 1 may be employed are in the context of water supply systems that routinely add chemicals, such as chlorine to a pool water supply. In such cases, if the flow of water in pipe 110 stops, there can be health risks associated with continuing to add the chemical(s), e.g. building up a dangerous chemical concentration in a small volume of stagnated water. Therefore, the sensor 120 may be configured to detect the flow of water in pipe 110 , and to send a signal to control unit 130 while the flow is active and/or if the flow stops. The control unit 130 may be configured to interrupt the power to device 140 if the signal indicates that the flow in pipe 110 has stopped, and/or if a signal that indicates positive flow is not received.
[0036] It is envisioned that the present subject matter may find applicability in a wide variety of contexts in which the benefits of constant or near constant industrial monitoring are not available, e.g. in household or small business environments. Therefore, another aspect of the invention may include communication between control unit 130 and a remote device 160 , such as a smartphone, smart watch, a tablet computer, etc. This communication link may be provided using various combinations of communication wires, power wires, or various wireless technologies known in the art, such as Bluetooth, WiFi, LAN, WAN or other means. In some examples, the control unit 130 and/or sensor unit 120 may be programmable via an application running on portable computing device, such as remote device 160 . Such programming may include parameters by which signals are generated and/or interrupted by the sensor unit 120 , and/or parameters by which the control unit interrupts the electrical circuit to device 140 . It should be appreciated that the sensor unit 120 may be configured to set a binary signal (e.g. there is or is not a flow), or it can be programmed to send more detailed information (such as rate of flow, pH, etc.) by which logic onboard the control unit 130 may determine whether certain control parameters are met. In some examples, the sensor unit itself may be programmed to read non-binary sensor data and to generate or interrupt the signal to control unit 130 based on comparing the non-binary sensor readings to programmed parameters.
[0037] In some examples, the system may be configured to send an alert to remote device 160 (via SMS message, Bluetooth signal, or various other addressing methods) if the flow in pipe 110 stops, or other condition(s) are met that interrupt the power being provided to device 140 . In this manner, the user of a household system or small business can be quickly and easily alerted to the problem state and can resolve the problem.
[0038] In some examples, since control unit 130 is plugged in to a power outlet, it has all the power necessary to maintain and/or perform intermittent communication with sensor 120 and/or remote device 160 . Control unit 130 may also be configured to provide low-current power to sensor 120 , e.g. via additional power outlets and/or wires. However, in some cases sensor 120 may be battery powered, self-powered, etc.
[0039] In some examples, control unit 130 may also be configured to report to remote device 160 if device 140 is not drawing power, e.g. if the device 140 has shut down due to a malfunction or other control such as running out of chemical in tank 150 .
[0040] Additional non-limiting examples of sensors and control modules according to aspects of the invention are discussed further below with reference to FIGS. 2-7 .
[0041] FIG. 2 is a schematic diagram of a flow sensor arrangement according to aspects of the invention. As shown in FIG. 2 , a sensor assembly 200 including a “paddle wheel” of permanent magnets 202 and an induction coil 204 may be partially inserted through a pipe 214 and clamped to the pipe via hose clamps 212 or other means. A gasket 206 around a flange of the sensor assembly 200 may provide a watertight seal between the sensor assembly and the hole in the pipe 214 . Rotation of the magnets 202 may be caused by water flow in the pipe 214 and may generate a signal from the sensor assembly 200 via the induction coil 204 proximate to the permanent magnets 202 . As shown in FIG. 2 , the signal may be carried over an electrical line 208 to the control unit, or it may be transmitted wirelessly. It should be noted that the output from the sensor assembly 200 may be configured in various ways. For example, a positive flow condition may result in a constant or intermittent signal, the interruption of which can signal a stop in the flow. In some examples, the steady signal may be fully or partially powered by the induction coil 204 . In some examples, a stop in the flow may initiate an independent signal that alerts the control unit. For example, the sensor assembly 200 may have control logic, and a battery, capacitor or other power source in the housing, that responds to the absence of current from the induction coil 204 by initiating a signal. In some examples, the induction coil 204 may be used to charge a battery or capacitor in the housing that are used to power the alert signal.
[0042] The sensor assembly 200 in FIG. 2 may also include a LED, sound, or other indicator 210 used to support visual or manual inspection, e.g. that lights when flow is detected, that sounds when flow is not detected, and/or changes color, illumination, sound, etc. when the sensor detects a change in flow.
[0043] FIG. 3 is a schematic diagram of multi-purpose sensor assembly 300 according to aspects of the invention. As shown in FIG. 3 , a sensor assembly 300 including one or more sensor probes 302 may be partially inserted through a pipe 314 and clamped to the pipe via hose clamps 312 or other means. It is noted that the interface between the sensor assembly 300 and the pipe 314 may be standardized such that various sensors can be attached using the same dimension hole or other mounting scheme. A gasket 306 around a flange of the sensor assembly 300 may provide a watertight seal between the sensor assembly 300 and the hole in the pipe 314 . The sensor probes 302 inserted into the pipe, or otherwise positioned to detect the desired condition, may be configured, for example, to detect electrical current, temperature, pH, or various other conditions that may be relevant to the operation of another device such as shown in FIG. 1 . For example, if a heater or other device is malfunctioning, the sensor in FIG. 3 may be used as an additional safeguard to shut down the device even when the device's own safeguards are not working. As shown in FIG. 3 , the signal may be carried over an electrical line 308 to the control unit, or it may be transmitted wirelessly. It should be noted that the output from the sensor assembly 300 may be configured in various ways, depending on the condition(s) that are being sensed. For example, an electrical current, pH, or chemical level, above a certain threshold may initiate an independent signal that alerts the control unit, or the signal may include non-binary information that is constantly, or periodically, transmitted to the control unit.
[0044] The sensor assembly 300 in FIG. 3 may also include a LED, sound, or other indicator 310 used to support visual or manual inspection, e.g. that lights when current is detected, that sounds when a certain pH level or range is detected, and/or changes color, illumination, sound, etc. when the sensor detects a change in relevant condition.
[0045] FIG. 4 is a schematic diagram of a pressure/vacuum sensor assembly 400 according to aspects of the invention. As shown in FIG. 4 , a sensor assembly 400 including one or more pressure/vacuum sensors 402 may be partially inserted through a pipe 414 and clamped to the pipe via hose clamps 412 or other means. As previously mentioned, the interface between the sensor assembly 400 and the pipe 414 may be standardized such that various sensors can be attached using the same dimension hole or other mounting scheme. A gasket 406 around a flange of the sensor assembly 400 may provide a watertight seal between the sensor assembly 400 and the hole in the pipe 414 . As shown in FIG. 4 , the pressure/vacuum signal may be carried over an electrical line 408 to the control unit, or it may be transmitted wirelessly. The sensor assembly 400 may be configured to send the signal when the pressure/vacuum meets certain criteria and/or the signal may include specific pressure/vacuum information that is constantly, or periodically, transmitted to the control unit.
[0046] It is noted that any of the sensor units described above can include programmable logic, e.g. on a storage device, by which a user can set parameters of the sensor such as ranges or thresholds for sending alert signals to the control unit, signal timing, wireless communication address and/or synchronization information, etc.
[0047] FIG. 5 is a front schematic diagram of a control unit according to aspects of the invention. As shown in FIG. 5 , the control unit 500 may include a standard electrical receptacle 510 that receives, for example, 2 or 3-prong electrical plugs such as Type A and/or Type B connectors. A plurality of visual or other indicators may be included, e.g. an LED power indicator 502 indicating that the control unit is receiving power, an LED sensor indicator 504 indicating that the control unit is coupled to a sensor unit, an LED alarm indicator 506 indicting that the internal circuit has been interrupted, etc. The control unit 500 may be configured to plug into a standard receptacle, similar to the electrical receptacle 510 that is on the face of the control unit. However, in some embodiments, a control unit may be hard-wired to an electrical power line (e.g. as a replacement wall receptacle) and/or to a device (e.g. permanently connected to the power supply line of the device). Screw 508 may be configured to penetrate the control unit 500 for attachment to a corresponding hole in a wall receptacle.
[0048] FIGS. 6 and 7 are side views of a control unit according to aspects of the invention. As shown in both of these figures, the control unit 600 may include standard electrical plugs 612 , e.g. extending from the back surface of the control unit 600 . Inside of the control unit 600 , an interruptible electrical circuit may be provided between the plugs 612 shown in FIGS. 6 and 7 , and the female receptacles 610 and/or the receptacles 510 shown in FIG. 5 . The means by which the circuit(s) are interruptible may take various forms including electrically powered switching elements, breakers, etc. In some examples, the control unit 600 may include a manual switch 616 that disposes the control unit in either of a normally open or normally closed configuration. As such, it may also be possible for the control unit 600 to maintain an interrupted (off) state until a signal is received and/or threshold is detected, and then close the circuit to an “on” state based on the signal or threshold. Such modifications may be advantageous, for example, when a device should be turned on only under certain circumstances, such as a sump flood, etc.
[0049] Individual control units may also include multiple sensor inputs and/or channels by which the control unit can communicate with multiple sensor units. For example, as shown in FIG. 7 , the control unit may include a plurality (in this case 4) sensor input/power connections 718 with a standardized interface for connecting similar or dissimilar sensors units to the control unit. One or more manual switches 716 may also be provided that alter a configuration associated with one or more of the sensor input/power connections 718 . For example, the switch 716 may alter a mode of the I/O such that a signal activates or deactivates a receptacle 610 , it may turn output power to one or more of the sensor input/power connections 718 on or off, etc.
[0050] The control units shown in FIGS. 5-7 may include various programmable logic, e.g. on a storage device, by which a user can set parameters regarding any of the sensor units coupled to the control unit, ranges or thresholds for interrupting the internal circuit, query timing, wireless communication address and/or synchronization information, etc.
[0051] In some examples, the control unit shown in FIGS. 5-7 may also include a wireless communication device by which the control unit can communicate with sensor units and/or with a remote device such as 160 shown in FIG. 1 . The control unit may be configured to transmit an alert to such a remote device when a circuit is interrupted and/or is closed based on sensor information as described herein.
[0052] In some examples, the control unit, sensors, and/or cables may be watertight and/or resistant to chemicals, humidity, and may be configured/constructed to operate in extreme temperatures, e.g. ranging from 0° F. to 140° F., or as otherwise required.
[0053] Although configurations using standard household electrical connections have been described, it should be understood that the invention is not limited to such configurations, and that control units can be, for example, enlarged and/or expanded for new and specialty installations and/or hard wire installs.
[0054] Additional sensors that detect, for example, water, light, sound, UV and/or IR light, radar, Bluetooth, Wi-Fi, etc. can be implemented with a control unit as described herein. The sensor must simply generate an I/O signal and may be powered by the control unit (e.g. 12 or 24 VAC/VDC). Likewise, additional electronics can be installed in the sensor unit to accommodate various control unit designs such as described herein.
[0055] In some examples, the control unit and/or sensor units may be made from ABS or other plastic and may be be designed as not to require additional bonding and/or grounding devices or connections.
[0056] In some examples, sensor cables may be be shielded from external EMP/EMF according to specific requirements.
[0057] While various embodiments have been described above, it is to be understood that the examples and embodiments described above are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art, and are to be included within the spirit and purview of this application and scope of the appended claims. Therefore, the above description should not be understood as limiting the scope of the invention as defined by the claims. | An electrical control system may include a sensor unit with an attachment mechanism for mounting the sensor unit to a fluid pipe, a fluid flow sensor, and a signal generator configured to generate a signal indicating at least one of whether the flow sensor detects a fluid flow in the fluid pipe or whether the flow sensor detects no fluid flow in the fluid pipe. The system may also include a control unit having one or more of an electrical plug, an electrical socket, an interruptible circuit between the electrical plug and the electrical socket, a receiving device configured to receive the signal from the sensor unit, and a processor configured to interrupt the circuit between the electrical plug and the electrical socket based on at least one of receipt of the signal or interruption of the signal. | 7 |
FIELD OF THE INVENTION
The present invention relates to connectors of a control bar for connecting the control bar to a louvre movable within a window or door structure.
BACKGROUND OF THE INVENTION
Traditional movable louvre structures are made of wood. A control bar is used to move a plurality of louvres in unison with one another. The control bar is secured to the louvres by means of small staples embedded in the wood material forming the louvres.
The above arrangement is not feasible when working with plastic or vinyl shutters. Furthermore, even with a wooden shutter, the staples connecting the control bar to the shutters are often pulled out and difficult to reinsert in the wood, particularly by the home user of the shutter.
SUMMARY OF THE INVENTION
The present invention provides a much more positive means of connecting a control to a louvre movable within a louvre window or door structure. Specifically, a louvre control of the present invention includes a connector for connecting the control to a moveable louvre having an undercut recess for receiving the connector. The connector is normally set in a louvre connecting position, is moveable to a louver recess insertion position and is biased to return to the louvre connecting position after it has been fitted into the louvre.
The connector, once inserted in the louvre, will not pull out without either breaking or deliberately removing the connector.
BRIEF DESCRIPTION OF THE DRAWINGS
The above as well as other advantages and features of the present invention will be described in greater detail according to the preferred embodiments of the present invention in which:
FIG. 1 is a perspective view of a shutter including a plurality of moveable louvres and a control bar connected to and operating the louvres in accordance with a preferred embodiment of the present invention;
FIG. 2 is a bottom perspective view of part of the control bar shown in FIG. 1 of the drawings;
FIG. 3 is an enlarged perspective view showing set up for connecting of the control bar of FIG. 2 to a pair of louvres from the shutter of FIG. 1;
FIGS. 4 through 6 show the different stages of insertion of one of the connectors of the control bar into one of the louvres in FIG. 3;
FIG. 7 is a sectional view looking down into the control bar and showing its connection with one of the louvres from the shutter of FIG. 1;
FIG. 8 is an enlarged partially exploded perspective view of a control bar connected to two shutters according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a louvred shutter generally indicated at 1 and preferably constructed from vinyl or some other similar type of resin material. This shutter is formed by an outside frame including styles 3 and opposite end headers 5. In this particular arrangement, a centre frame section 6 is also provided extending between the styles 3.
Trapped within the frame are a plurality of moveable louvres 7. Each of these louvres includes opposite end pins or axles which are rotationally secured within the styles and allowing pivotal movement of the louvres.
In the shutter shown in FIG. 1, the louvres are arranged in two groups, one above and one below the centre frame section 6. The louvres in each group are moveable in unison with one another by means of a control bar including bar member 11. The control bar includes a plurality of connectors generally indicated at 15 as best seen in FIGS. 2 and 3 of the drawings with each connector being secured to one of the individual louvres.
The louvres themselves as best seen in FIGS. 4 through 6 of the drawings have a hollow construction. Each louvre has an opening generally indicated at 9 centrally of its wing-like edge. This opening in combination with the hollow construction provides an undercut recess within the louvre. The undercut recess is used for connecting or trapping one of the connector members 15 as will be described later in greater detail.
Each connector 15 is formed by first and second connector portions 17 and 19. These two portions are molded as a common unit at a generally right angle as shown in FIGS. 6 and 7 of the drawings. Connector portion 19 includes a cut-out region 20 which in combination with a bendable plastic construction of the connector allows bending of connector portion 17 relative to connector portion 19 away from its molded configuration to a configuration where the two connector portions are much more in line with one another as shown in FIG. 4 of the drawings. This bending of connector portion 17 moves the overall connector from what will be referred to as a connecting position to an insertion position. When the connector is in the connecting position, it will not fit through the opening to the hollow interior of the louvre. However, by varying the angle between the two connector portions, i.e., by bending the first connector portion away from its right angle setting to a more in-line position with respect to the second connector portion, connector portion 17 is fittable through the louvre opening as shown in FIGS. 4 and 5 of the drawings. Once connector portion 17 is fitted within the louvre, the memory of the material causes it to move back to its molded connecting position of FIG. 3. In this position, the span across connector portion 17 is greater than the width across opening 9 which is the reason that connector portion 17 cannot be inserted into the opening without first bending it and which is also the reason that connector portion 17, once fitted through the opening, is trapped inside the louver.
The overall connector 15 is preferably constructed of polypropylene which has very positive characteristics to enhance operation of the connector. In particular, polypropylene, while being bendable without breaking, has a memory which causes it quickly to return to its molded form. Furthermore, it will take substantial abuse without damage or breaking.
Another feature of the connector is the provision of small cut away areas or recesses 21 in connector portion 19. The provision of recesses 21 eases the force required in order to align or substantially align the two connector portions with one another but does not detract from the memory of the material for returning to its pre-molded configuration.
The control bar itself has a multi-component construction best shown in FIG. 8 of the drawings. As was earlier noted, bar member 13 includes the actual connectors 15. Additionally provided is a sheath or cover 23 which includes an undercut recess 24 for sliding over and securing to bar member 13. The overall assembly is then completed by means of upper and lower end caps 25, each of which includes tabs 27 frictionally engaged within sheath 23.
In the event that bar member 13 or any of the connectors 15 are damaged, one simply has to remove one of the end caps 25, slide sheath 23 off of and replace bar member 13 while still being able to reuse the sheath and end caps. This provides an obvious cost benefit to the consumer if any of the connectors should happen to fail.
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims. | A louvre control for operating moveable louvres of a window or door structure is connectable to a louvre having an undercut recess for receiving a connector on the control. The connector is normally set in a louvre connecting position, is moveable to a louvre recess insertion position and is biased to return to the louvre connecting position after it is inserted into the undercut recess of the louvre. | 4 |
[0001] This application claims priority of U.S. provisional application No. 61/168,383 filed Apr. 10, 2009.
FIELD OF THE INVENTION
[0002] This invention relates to mail sorting machines and methods.
BACKGROUND OF THE INVENTION
[0003] Known mail sorting systems such as DBCS and MLOCR machines include a feeder that feeds mail pieces one at a time to a pinch belt conveyor that transports singulated mail pieces during the sorting process. In one common version of such a system, a pickoff belt mechanism is positioned to frictionally engage an outer surface of a mail piece at the end of a stack and transport it transversely to a thickness direction of the stack, which pickoff mechanism includes one or more belts mounted on rollers and driven by a drive motor; a sensor positioned to determine mail piece movement speed as the mail piece is being transported by the pickoff belt mechanism; a measurement device for determining belt movement speed during operation of the pickoff belt mechanism a vacuum pump; a vacuum manifold connected to the vacuum pump, wherein the vacuum manifold is positioned to apply suction to the mail piece in a direction that tends to hold the mail piece against the belt of the pickoff belt mechanism; optionally means for stopping slipping of the mail piece relative to the belt during transport by the belt pickoff mechanism may also be provided, such as by temporarily increasing suction force applied to a mail piece being transported by the pickoff belt mechanism. Two known pickoff mechanisms are shown in U.S. Patent publications 20100034623 PICKOFF MECHANISM FOR MAIL FEEDER and 20100032889 PICKOFF MECHANISM FOR MAIL FEEDER.
[0004] A stripper is commonly provided at a position a short distance upstream from the pickoff belts. A problem arises when the pickoff belts remove two mail pieces at the same time from the stack. When such a double feed happens, a stripper is positioned a short distance upstream. See e.g. Enenkel U.S. patent pub 20090206014—stripper 56. The stripper generally takes the form of a metal plate or block, that is, a friction shoe that is positioned to contact and pull off a second mail piece resting side by side with the first fed through. The second mail piece is later carried on into the pinch belt transport belts after the first one has been carried on.
[0005] The stripper plays a key role in singulation of mail on feeders. However, slow response time and improper damping of existing strippers leads to frequent doubles. The location of the friction surface is governed by the location of brackets and a bar mechanism onto which the friction shoes are mounted. The friction shoes wear over time and therefore the location of the friction surface has to be adjusted by adjusting the location of mounting brackets. Contrary to the desired dragging mode of force application on the mail pieces, known strippers apply a normal (perpendicular) load on the mail piece. In one known stripper the links used for shoe mounting are rigid hence a large point force acts on the mail and the mail is constrained at single point. The mail pieces being fed therefore can flap, bend and become damaged. The normal spring forces lead to head-on impact of the mail with the friction shoe. Large impact and corresponding displacement of the friction shoes causes lots of noise. Little attention has been paid in the art to the fabrication of the stripper and means of improving its performance. The present invention addresses these issues.
SUMMARY OF THE INVENTION
[0006] A stripper of the invention is dimensioned for use in a feeder mechanism for singulated mail pieces transported on a pinch belt conveyor. The stripper has a flexible backing sheet having an outwardly exposed friction surface for applying friction to a face of a passing mail piece, a friction shoe including a leaf spring disposed beneath the backing sheet such that external pressure against the friction surface results in resilient bending of the spring such that force is exerted outwardly against the backing by the spring. The spring preferably comprises a flat leaf spring oriented so that the leaf spring bends resiliently in response to a sufficient external pressure against the friction surface.
[0007] A mail piece feeder according to the invention comprises a pickoff mechanism including a pickoff belt mounted on rollers including a drive roller, the pickoff belt positioned to frictionally engage a mail piece at one end of a stack of mail positioned on a side edge of the mail pieces, and a stripper positioned at an exit of the pickoff belt, which stripper engages an overlying mail piece of a pair of mail pieces including an underlying mail piece and the overlying mail piece fed together in a double feed, stripping it from the underlying mail piece, wherein the stripper has a flexible backing sheet having an outwardly exposed friction surface for applying friction to a face of a passing mail piece and a friction shoe including a leaf spring disposed beneath the backing sheet such that external pressure against the friction surface results in resilient bending of the spring such that force is exerted outwardly against the backing by the spring.
[0008] These and other aspects of the invention are described further in the detailed description that follows. It is to be understood that terms used in the present invention should be given their meanings recognized in the postal sorting art, if applicable, not more general definitions found in dictionaries.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In the accompanying drawings, where like numerals denote like elements and letters denote multiples of a component.
[0010] FIG. 1 a is a top plan view of a stripper according to the invention;
[0011] FIG. 1 b is an isometric side view of the stripper of FIG. 1 a according to the invention;
[0012] FIG. 1 c is a second isometric side view of the stripper of FIG. 1( a );
[0013] FIG. 2 is a plan view of a stripper according to the invention;
[0014] FIG. 3 is a top view of a pickoff mechanism according to the invention; and
[0015] FIG. 4 is a view similar to FIG. 3 illustrating force relationships needed for singulation of mail pieces using a pickoff mechanism of the invention.
SUMMARY OF THE INVENTION
[0016] The present invention among other things provides a stripper which uses flat metal springs (leaf springs) preferably made of spring steel and a flexible polymer based friction material covering the springs on one side so that the friction material contacts an incoming mail piece passing by the stripper along the friction surface presented by the outside of the friction material.
[0017] A stripper according to the invention has variable stiffness, is quick responding, and is critically damped, meaning that incoming mail pieces will not bounce off it with excessive force likely to cause a misfeed or loss of control of the mail piece as has been a problem with known stripper designs.
[0018] Strippers play a key role in singulation of mail on feeders. In typical feeders used in sorters, however; slow response time and improper damping of existing strippers leads to frequent doubles. One such prior art device uses one or more friction shoes that engage passing mail pieces and is mounted on a set of coil springs. Use of coil springs in this manner renders the stripper less stable and more likely to cause a misfeed. Location of the friction surface in this device is governed by the location of brackets and bar mechanism onto which the friction shoes are mounted. The friction shoes wear over time and therefore the location of the friction surface has to be adjusted by adjusting the location of mounting brackets. Contrary to the desired dragging mode of force application on passing mail pieces, the known strippers including the foregoing spring loaded device apply a primarily “normal i.e. perpendicular” load on the mail. In the known stripper the links used for shoe mounting are rigid hence a large point force acts on the mail and the mail is constrained at single point. The mail therefore can flap, bend and be damaged. The normal spring forces lead to head on impact of the mail with the stripper shoes. Large impacts of this kind and corresponding displacement of the friction shoes causes excessive noise as well as increasing the chance of a misfeed.
[0019] In view of the above drawbacks of the existing strippers, a stripper according to the invention seeks to remedy such problems. The stripper of the invention exhibits better performance than the existing stripper using coil springs as described above.
[0020] A mail piece stripper according to the invention refers to a device that is positioned or positionable downstream from a mail piece feeder that has a pickoff mechanism that removes mail pieces one at a time from the end of a stack of mail pieces, which device is effective to contact and strip away a second mail piece from a first one when the first and second mail pieces comprise a double feed by the feeder. Contact between the stripper and the second mail piece causes the second mail piece to be stripped away from the first.
[0021] These and other aspects of the invention are described more fully in the detailed description that follows.
DETAILED DESCRIPTION
[0022] A stripper 10 of the invention is based on usage of the spring steel and flexible polymer based friction material arranged in laminated fashion with steel leaf springs according to the invention as described in FIGS. 1 a to 1 e.
[0023] FIGS. 1 a - 1 b show the free state of a stripper 10 of the invention, whereas FIG. 2 describes the configuration of the stripper 10 when it is mounted in the pickoff mechanism 30 of a postal processing machine such as a letter sorter provided with a feeder 20 of which pickoff mechanism 30 is part for removal of mail pieces one at a time by being drawn off sideways by pickoff 30 from a mail stack 22 .
[0024] Stripper 10 in this embodiment comprises a friction shoe 11 that is positioned so that a passing mail piece 12 being conveyed by the pickoff belts 27 , which may be the outer mail piece of a double (pair of mail pieces face to face fed as a double feed, slides along an outside face of shoe 11 in the direction of travel of mail pieces 12 on feeder 20 as it conveys them to a pinch belt conveyor that is part of the postal processing machine for further transport. A fence (flange) 21 is positioned to help prevent fed mail pieces 12 from coming loose from feeder 20 .
[0025] As shown in FIGS. 1A , 1 B and 2 , the friction shoe 11 comprises resilient flat steel leaf springs 15 , 16 and 18 mounted at proximal ends to a bracket 19 or a spacer 17 under a sheet of flexible backing material 14 . The flexible backing material 14 is made from a flexible polymer such as a sheet of polyurethane. The outer surface 13 of backing 14 acts as a friction surface that provides a stripping action on passing mail pieces 12 . The underlying springs discussed below are configured to resiliently flex when friction shoe 11 engages a mail piece 12 as shown in FIG. 2 , and the springs 15 , 16 and 18 press the outer friction surface 13 of backing 14 against the mail piece 12 . A nylon flap 25 is positioned to aid mail pieces to move smoothly past the friction shoes 11 .
[0026] The springs of each shoe 11 include a long leaf spring 15 are engaged longitudinally along the backing material 14 . The long leaf spring(s) 15 provide the spring force to the friction shoe 11 in order to apply load on the mail stack 22 . These springs 15 (one per shoe 11 ) slip on the inside surface of the polymeric backing material 14 for enabling the critical dampening of the mechanism. Another set of leaf springs 16 are shorter and stiffer than long springs 15 and are arranged longitudinally behind the long leaf springs 15 . The stiff springs 16 establish point contact at the tip with the first row of springs 15 . The spring 16 slips along the point of contact with spring 15 and ensures that the spring constant of the compound springs (i.e. working together against a common return force) is variable. The variability of the spring contact ensures that the forces acting on the mail pieces do not increase significantly over a starting value.
[0027] A “row” of springs according to this aspect of the invention refers to two or more springs of the same type disposed side by side as part of two or more shoes 11 . In this embodiment each shoe 11 includes a set (one each) of springs 15 , 16 and 18 (arranged as shown) in each of shoes 11 . In this manner springs 15 , 16 and 18 in each friction shoe 11 form a row of three springs which are side by side.
[0028] A set of weak springs 18 is mounted on a bracket 19 located in the rear of shoe 11 . The weak springs 18 engage with the first row of springs 5 along the tips. The function of these springs 18 is to provide additional constraint and prevent flapping of the mail pieces 12 during movement past stripper 10 .
[0029] FIG. 3 shows the forces acting on a single mail piece 12 as it moves on feeder 20 and passes stripper 10 . The stripping action is governed by the interplay of various forces acting along the mail piece 12 . As shown in FIG. 3 , the mechanical interfaces and corresponding loads offered to the mail pieces 12 include the mail-mail, mail-pickoff belt and mail-stripper shoe interfaces. Singulation of a single mail piece 12 from stack 22 at any given time is ensured by application of suitable differential frictional force. F1 is the frictional force acting on the mail along the pickoff belt-mail interface, F2 is the force acting along the mail-stripper interface and F3 is the force acting along the mail and stack interface. For the mail pieces 12 to properly go past, the stripper 10 ensures that the force F1 exceeds the cumulative F2 and F3 i.e. (F1>F2+F3).
[0030] Similarly the prevention of double feeds is ensured by the application of suitable\ differential forces between the mail pieces 12 when two or more mail pieces 12 get dragged into the singulation area. As shown in figure frictional force at the stripper shoe 11 mail interface should be higher than frictional force between two mail pieces. On the other hand, the frictional force between the pickoff 30 belt and mail interface should be higher than both mail-mail interface and mail-stripper shoe interface. The forces acting on the first mail piece include the frictional force from the pickoff belt and the friction force from the adjacent mail piece. The second mail piece Mail2) adjacent to the first mail piece (Mail1) has a set of forces acting upon it. The forces acting on the second mail piece includes the pull from the first mail piece and the dragging forces from the stripper and stack respectively. In order to insure proper singulation action, the net pickoff force acting on the first mail piece must exceed the frictional force between the two mail pieces. Also the pullback force of the stripper and stack acting on the second mail piece must exceed the dragging force coming from the first mail piece. F1 is the frictional force acting on the mail along the pickoff belt-mail interface, F2 is the force acting along mail-stripper interface, F3 the force acting along the mail and stack interface and F4 the force acting along the mail-mail interface, the stripper design of the invention ensures that absolute value of F1 is larger than absolute value of F4 (|F1|>|F 4 |). Similarly, the stripper 10 also ensures that the cumulative sum of absolute values of F2 and F3 is higher than that of F4 (|F2|+|F3|>|F4|).
[0031] As shown in FIG. 4 , frictional force at the stripper shoe-mail interface should be higher than functional force between two mail pieces. On the other hand, the frictional force between the pickoff belt and mail interface should be higher than both mail-mail interface and mail-stripper shoe interface. The forces acting on the first mail piece include the frictional force from the pickoff belt and the friction force from the adjacent mail piece. The second mail piece adjacent to the first mail piece has a set of forces acting upon it. The forces acting on the second mail piece includes the pull from the first mail piece and the dragging forces from the stripper and stack 22 respectively. In order to insure proper singulation action, the net pickoff force acting on the first mail piece must exceed the frictional force between the two mail pieces. Also, the pullback force of the stripper and stack acting on the second mail must exceed the dragging force coming from the first mail piece. For F1 being the frictional force acting on the mail along the pickoff belt-mail interface, F2 the force acting along mail-stripper interface, F3 the force acting along the mail and stack interface and F4 the force acting along the mail-mail interface, the stripper design ensures that absolute value of F1 is larger than absolute value of F4 (|F1|>|F4|). Similarly, the stripper also ensures that the cumulative sum of absolute values of F2 and F3 is higher than that of F4 (|F2|+|F3|>|F4|).
[0032] On the other hand, the frictional force between the pickoff belt and mail interface should be higher than the frictional forces at both the mail-mail interface and mail-stripper shoe interface. The mail pieces that are fed have wide range of geometric and physical properties. For a consistent performance of the stripper, the invention ensures that the performance of the stripper is independent of the physical properties of the mail.
[0033] The laminated arrangement of the springs and backing material ensure that the friction surface is flexible and therefore establishes a constant engagement of the mail and friction surface along every point of the mail in the entry region. This attribute of the stripper design ensures that the entry of the mail into pickoff 30 is conformal and all the degrees of freedom of the mail are arrested. The mail therefore does not flap sideways and is confined along the conformal entry established by the flexible friction surface. Also the dominating stiffness of the spring material will prevent the formation of local bending of friction material and hence trapping/flapping/bending of the mail.
[0034] Wherever required there are a set of multiple springs arranged in rows laminated format, that is, covered by plastic backing 14 . The multiple springs are free to move relative to each other. This attribute allows the spring to have variable spring stiffness and therefore the loads acting on the mail are independent of the geometry of the mail. The slipping of the springs allows spring force to be sustained within allowable limits. On the contrary if the springs are not allowed to have relative motion with respect to each other, the force will increase with the bending and engagement of more springs.
[0035] The friction material is arranged in a laminated fashion so that the relative motion of the spring and shoe allows critical dampening. The critical dampening will enable quick settling of the stripper and therefore increase the availability of the stripper interface.
[0036] The laminated arrangement of the springs and flexible backing material is held towards the rear regions of the shoe 11 and bend along normal direction so that a conformal wedge shaped entry region is created. This wedge shaped entry region ensures that the entry of the mails is smooth and there is no head on impact between the entering mail piece 12 and stripper 10 . Also, the pattern of bending ensures that the forces acting on the mail are lateral drag forces.
[0037] These include the frictional force from the pickoff belt and the friction force from the adjacent mail piece. The second mail piece adjacent to the first mail piece has a set of forces acting upon it. The forces acting on the second mail piece includes the pull from the first mail piece 12 and the dragging forces from the stripper 10 and stack respectively. In order to insure proper singulation action, the net pickoff force acting on the first mail piece must exceed the frictional force between the two mail pieces. Also the pullback force of the stripper and stack 22 acting on the second mail must exceed the dragging force coming from the first mail piece. Let F1 be the frictional force acting on the mail along the pickoff belt-mail interface, F2 the force acting along mail-stripper interface, F3 the force acting along the mail and stack interface and F4 the force acting along the mail-mail interface, the stripper 10 ensures that absolute value of F1 is larger than absolute value of F4 (|F1|>|F4|). Similarly, the stripper 10 also ensures that the cumulative sum of absolute values of F2 and F3 is higher than that of F4 (|F2j+|F3|>|F4|).
[0038] In the foregoing manner the stripper of the present invention can be configured in a manner that operates smoothly and rapidly with the problems with excessive noise and misfeeds which characterize the prior art stripper using coil springs. If noise is not an issue, it is also possible to use small coil springs in place of the leaf springs described above, but leaf springs have been shown to provide superior performance as compared to devices using coiled compression springs.
[0039] Although several embodiments of the present invention have been described in the foregoing detailed description and illustrated in the accompanying drawings, it will be understood by those skilled in the art that the invention is not limited to the embodiments disclosed but is capable of numerous rearrangements, substitutions and modifications without departing from the spirit of the invention. Such modifications are within the scope of the invention as expressed in the appended claims. | A stripper of the invention uses flat metal springs (leaf springs) preferably made of spring steel and a flexible polymer based friction material covering the springs on one side so that the friction material contacts an incoming mail piece passing by the stripper along the friction surface presented by the outside of the friction material. A stripper according to the invention has variable stiffness, is quick responding, and is critically damped, meaning that incoming mail pieces will not bounce off it with excessive force likely to cause a misfeed or loss of control of the mail piece. | 1 |
BACKGROUND OF THE INVENTION
[0001] (1) Field of the Invention
[0002] This invention relates to a process for preparing an acrylate compound which is expected to be used as a raw material for functional polymers, pharmaceuticals and pesticides.
[0003] (2) Description of the Related Art
[0004] In recent years acrylate compounds have provided a great attraction, for example, as monomers used for producing a resist for advanced semiconductor lithography. Especially acrylate compounds having a tertiary ester skeletal structure capable of being dissociated with an acid are suitable therefor in view of lithography mechanism.
[0005] As specific examples of the acrylate or methacrylate compounds having such a skeletal structure capable of being dissociated with an acid, there can be mentioned acrylates and methacrylates having an acid-dissociatable group such as a 2-methyl-2-adamantyl group or a 8-ethyl-8-tricyclodecanyl group (Japanese Unexamined Patent Publication [hereinafter abbreviated to “JP-A”) No. 2001-188352, JP-A H11-305444 and JP-A H9-43848), and α-trifluoromethylacrylates having an acid-dissociatable group such as a 2-methyl-2-adamantyl group or a 1-alkyl-1-cycloalkyl group (JP-A 2001-302728).
[0006] The above-mentioned acrylate compounds are prepared, for example, by the following known processes.
[0007] A first type process comprises allowing an acrylic acid chloride compound to react with an alcohol or a metal alcoholate in the presence of a base. The first type process includes, for example, a process wherein 2-methyl-2-adamantanol is allowed to react with acryloyl chloride or methacryloyl chloride in the presence of triethylamine to give a corresponding acrylate or methacrylate compound (for example, JP-A H11-305444, JP-A 2000-122294, JP-A 2000-229911 and JP-A 2001-188352), and a process wherein 8-ethyl-8-cyclododecanol is allowed to react with methacryloyl chloride in the presence of triethylamine (JP-A 2001-188352). The first type process further includes a process wherein 2-adamantanone is allowed to react with methyllithium or a methyl Grignard reagent to give a Li or Mg salt of 2-methyl-2-adamantanonol, and then, methacryloyl chloride is added in a solution of the thus-obtained Li or Mg salt to give a corresponding methacrylate compound (JP-A H10-182552 and JP-A 2000-229911).
[0008] The first type process has a problem such that acryloyl chloride and methacryloyl chloride are not readily available and are expensive, and are difficult to handle because these acid chlorides easily produce a large amount of hydrogen chloride gas when they are contacted with moisture in the air.
[0009] As a process wherein acryloyl chloride and methacryloyl chloride are not used to overcome the first type process, a second process has been proposed which includes, for example, a process wherein acrylic acid is allowed to react with a tertiary alcohol such as 1-ethyl-1-cyclohexanol (JP-A 2000-319226).
[0010] However, in the second process, large amounts of a carboxylic acid anhydride such as acetic anhydride and an amine compound such as triethylamine must be used to smoothly carry out the reaction, with the result of reduction in efficiency and cost for production.
SUMMARY OF THE INVENTION
[0011] In view of the foregoing, a primary object of the present invention is to provide a process for preparing acrylate compounds whereby the object compounds can be prepared with high efficiency without the above-mentioned problems of the prior art, namely, with a reduced cost and an enhanced safety.
[0012] Thus, in accordance with the present invention, there is provided a process for preparing an acrylate compound represented by the following formula (4):
[0013] wherein R 1 and R 2 independently represent a hydrogen atom or a fluorine atom, R 3 represents a hydrogen atom, a fluorine atom, an alkyl group, an alkenyl group, a fluoroalkyl group, or a fluoroalkenyl group, R 4 and R 5 independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, a halogenated alkyl group, or a halogenated alkenyl group; and X and Y independently represent a hydrocarbon group, which may have at least one substituent selected from the group consisting of a halogen-containing substituent, an oxygen-containing substituent and a nitrogen-containing substituent, and dashed line - - - - - means that X and Y may be bonded together to form a cyclic structure;
[0014] which comprises allowing an acrylic acid compound represented by the following formula (1):
[0015] wherein R 1 , R 2 and R 3 are the same as defined above for formula (4), to react with an unsaturated compound represented by the following formula (2) or (3):
[0016] wherein R 4 , R 5 , X and Y are the same as defined above for formula (4).
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] The acrylic acid compound used as a raw material in the process of the present invention is represented by the above formula (1). In formula (1), R 1 and R 2 independently represent a hydrogen atom or a fluorine atom, and preferably represent a hydrogen atom.
[0018] In formula (1), R 3 represents a hydrogen atom, a fluorine atom, an alkyl group, an alkenyl group, a fluoroalkyl group or a fluoroalkenyl group. R 3 is preferably selected from a hydrogen atom, a fluorine atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched fluoroalkyl group, and a C 2 -C 4 straight-chain or branched fluoroalkenyl group. As specific examples of the alkyl group, there can be mentioned methyl, ethyl, propyl and butyl groups. As specific examples of the alkenyl group, there can be mentioned ethenyl, 1-propenyl, allyl and 1-, 2- or 3-butenyl groups. As specific examples of the fluoroalkyl group, there can be mentioned fluoromethyl, fluoroethyl, fluoropropyl and fluorobutyl groups. As specific examples of the fluoroalkenyl group, there can be mentioned fluoroethenyl, fluoro-1-propenyl, fluoroallyl and fluoro-1-butenyl, fluoro-2-butenyl and fluoro-3-butenyl groups.
[0019] Preferable examples of the acrylic acid compound of formula (1) are those wherein R 1 and R 2 are a hydrogen atom, and R 3 is selected from a hydrogen atom, a fluorine atom, an alkyl group (preferably a C 1 -C 4 straight-chain or branched alkyl group), an alkenyl group (preferably a C 2 -C 4 straight-chain or branched alkenyl group), a fluoroalkyl group (preferably a C 1 -C 4 straight-chain or branched fluoroalkyl group) and a fluoroalkenyl group (preferably a C 2 -C 4 straight-chain or branched fluoroalkenyl group).
[0020] As specific examples of the acrylic acid compound, there can be mentioned acrylic acid, methacrylic acid, α-ethylacrylic acid, α-n-propylacrylic acid, α-isopropylacrylic acid, α-n-butylacrylic acid, α-isobutylacrylic acid, α-s-butylacrylic acid, α-allylacrylic acid, α-t-butylacrylic acid, α-fluoromethylacrylic acid, α-trifluoromethylacrylic acid, α-fluoroacrylic acid, α-difluoroacrylic acid, α-trifluoroacrylic acid, α-fluoroethylacrylic acid, α-difluoroethylacrylic acid, α-trifluoroethylacrylic acid, α-tetrafluoroethylacrylic acid, α-perfluoroethylacrylic acid, α-fluoropropylacrylic acid, α-difluoropropylacrylic acid, α-trifluoropropylacrylic acid, α-tetrafluoropropylacrylic acid, α-pentafluoropropylacrylic acid, α-hexafluoropropylacrylic acid, α-perfluoropropylacrylic acid, α-fluorobutylacrylic acid, α-difluorobutylacrylic acid, α-trifluorobutylacrylic acid, α-tetrafluorobutylacrylic acid, α-pentafluorobutylacrylic acid, α-hexafluorobutylacrylic acid, α-heptafluorobutylacrylic acid, α-octafluorobutylacrylic acid, α-perfluorobutylacrylicacid, α-fluoroallylacrylic acid, α-difluoroallylacrylic acid, α-trifluoroallylacrylic acid, α-tetrafluoroallylacrylic acid, α-perfluoroallylacrylic acid, α-trifluoromethyl-β-fluoroacrylic acid, α-trifluoromethyl-β,β-difluoroacrylic acid and α,β,β-trifluoroacrylic acid.
[0021] Of these, α-trifluoromethylacrylic acid, α-trifluoroethylacrylic acid, α-perfluoroethylacrylic acid, α-perfluoropropylacrylic acid, α-perfluorobutylacrylic acid, α-fluoroacrylic acid, acrylic acid and methacrylic acid are preferable. α-trifluoromethylacrylic acid, acrylic acid and methacrylic acid are especially preferable.
[0022] The unsaturated compound used as a raw material in the process of the present invention is represented by the formula (2) or (3), which has at least one carbon-carbon double bond in the structure and at least one carbon atom of the carbon-carbon double bond is bonded to only carbon atoms, namely, is not directly bonded to any atom other than carbon atom. The skeleton of the unsaturated compound may be either a chain-like structure including a straight chain structure and a branched structure, or an alicyclic structure.
[0023] The above-mentioned unsaturated compound of formula (2) or (4) includes, for example, those which are represented by the following formulae (7) through (13).
[0024] Compounds represented by the following formula (7):
[0025] wherein R 7 and R 8 independently represent a hydrogen atom, a halogen atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, or a C 2 -C 4 straight-chain or branched haloalkenyl group, and R 9 and R 10 independently represent a C 1 -C 10 straight-chain or branched alkyl group, or a C 2 -C 10 straight-chain or branched alkenyl group;
[0026] compounds represented by the following formula (8):
[0027] wherein R 7 and R 8 independently represent a hydrogen atom, a halogen atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, or a C 2 -C 4 straight-chain or branched haloalkenyl group, and R 11 and R 12 independently represent a C 1 -C 10 straight-chain or branched alkyl group, or a C 2 -C 10 straight-chain or branched alkenyl group;
[0028] compounds represented by the following formula (9):
[0029] wherein R 7 and R 8 independently represent a hydrogen atom, a halogen atom, a C 1 -C 4 straight chain or branched alkyl group, a C 2 -C 4 straight chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, or a C 2 -C 4 straight-chain or branched haloalkenyl group, and R 13 represents a C 2 -C 15 straight chain or branched alkylene group or a C 2 -C 15 straight-chain or branched alkenylene group;
[0030] compounds represented by the following formula (10):
[0031] wherein R 7 and R 8 independently represent a hydrogen atom, a halogen atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, or a C 2 -C 4 straight-chain or branched haloalkenyl group, and R 14 represents a C 1 -C 15 alkylene group, or a C 2 -C 15 alkenylene group;
[0032] compounds represented by the following formula (11):
[0033] wherein R 7 and R 8 independently represent a hydrogen atom, a halogen atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, or a C 2 -C 4 straight-chain or branched haloalkenyl group, R 15 represents a C 1 -C 15 alkylene group or a C 2 -C 15 alkenylene group, and R 16 represents a C 1 -C 3 alkylene group;
[0034] compounds represented by the following formula (12):
[0035] wherein R 7 and R 8 independently represent a hydrogen atom, a halogen atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, or a C 2 -C 4 straight-chain or branched haloalkenyl group, R 17 represents a C 1 -C 15 alkylene group or a C 2 -C 15 alkenylene group, and R 18 represents a C 1 -C 3 alkylene group; and
[0036] compounds represented by the following formula (13):
[0037] wherein R 7 and R 8 independently represent a hydrogen atom, a halogen atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, or a C 2 -C 4 straight-chain or branched haloalkenyl group, and R 19 and R 20 independently represent a hydrogen atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, a C 2 -C 4 straight-chain or branched haloalkenyl group, a hydroxyl group, a C 1 -C 4 alkoxy group, an amino group, a carboxyl group, an ester group, a carbonyl group or a halogen atom.
[0038] As examples of the unsaturated compound of the above formula (9), there can be mentioned those which are represented by the following formulae (14) through (20).
[0039] Compounds represented by the following formula (14):
[0040] wherein R 7 and R 8 independently represent a hydrogen atom, a halogen atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or, branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, or a C 2 -C 4 straight-chain or branched haloalkenyl group, and R 21 independently represents a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, a C 2 -C 4 straight-chain or branched haloalkenyl group, a hydroxyl group, a C 1 -C 4 alkoxy group, an amino group, a carboxyl group, an ester group, a carbonyl group or a halogen atom, and n is an integer in the range of 0 to 8;
[0041] compounds represented by the following formula (15):
[0042] wherein R 7 , R 8 and R 21 are the same as defined above for formula (14), and n is an integer in the range of 0 to 10;
[0043] compounds represented by the following formula (16):
[0044] wherein R 7 , R 8 and R 21 are the same as defined above for formula (14), and n is an integer in the range of 0 to 6;
[0045] compounds represented by the following formula (17):
[0046] wherein R 7 , R 8 and R 21 are the same as defined above for formula (14), and n is an integer in the range of 0 to 8;
[0047] compounds represented by the following formula (18):
[0048] wherein R 7 , R 8 and R 21 are the same as defined above for formula (14), and n is an integer in the range of 0 to 6;
[0049] compounds represented by the following formula (19):
[0050] wherein R 7 , R 8 and R 21 are the same as defined above for formula (14), and n is an integer in the range of 0 to 8; and
[0051] compounds represented by the following formula (20):
[0052] wherein R 7 , R 8 and R 21 are the same as defined above for formula (14), and n is an integer in the range of 0 to 8.
[0053] As examples of the unsaturated compound of the above formula (10), there can be mentioned those which are represented by the following formulae (21) through (27).
[0054] Compounds represented by the following formula (21):
[0055] wherein R 7 and R 8 independently represent a hydrogen atom, a halogen atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, or a C 2 -C 4 straight-chain or branched haloalkenyl group, and R 21 independently represents a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, a C 2 -C 4 straight-chain or branched haloalkenyl group, a hydroxyl group, a C 1 -C 4 alkoxy group, an amino group, a carboxyl group, an ester group, a carbonyl group or a halogen atom, and n is an integer in the range of 0 to 7;
[0056] compounds represented by the following formula (22):
[0057] wherein R 7 , R 8 and R 21 are the same as defined above for formula (21), and n is an integer in the range of 0 to 9;
[0058] compounds represented by the following formula (23):
[0059] wherein R 7 , R 8 and R 21 are the same as defined above for formula (21), and n is an integer in the range of 0 to 5;
[0060] compounds represented by the following formula (24):
[0061] wherein R 7 , R 8 and R 21 are the same as defined above for formula (21), and n is an integer in the range of 0 to 7;
[0062] compounds represented by the following formula (25):
[0063] wherein R 7 , R 8 and R 21 are the same as defined above for formula (21), and n is an integer in the range of 0 to 5;
[0064] compounds represented by the following formula (26):
[0065] wherein R 7 , R 8 and R 21 are the same as defined above for formula (21), and n is an integer in the range of 0 to 7; and
[0066] compounds represented by the following formula (27):
[0067] wherein R 7 , R 8 and R 21 are the same as defined above for formula (21), and n is an integer in the range of 0 to 7.
[0068] Among the unsaturated compounds of formula (22), 1-ethylcyclohexene represented by the following formula (36) is especially preferable.
[0069] As examples of the unsaturated compound of the above formula (11), there can be mentioned those which are represented by the following formulae (28) through (31).
[0070] Compounds represented by the following formula (28):
[0071] wherein R 7 and R 8 independently represent a hydrogen atom, a halogen atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, or a C 2 -C 4 straight-chain or branched haloalkenyl group, and R 21 independently represents a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, a C 2 -C 4 straight-chain or branched haloalkenyl group, a hydroxyl group, a C 1 -C 4 alkoxy group, an amino group, a carboxyl group, an ester group, a carbonyl group or a halogen atom, and n is an integer in the range of 0 to 8;
[0072] compounds represented by the following formula (29):
[0073] wherein R 7 , R 8 and R 21 are the same as defined above for formula (28), and n is an integer in the range of 0 to 8;
[0074] compounds represented by the following formula (30):
[0075] wherein R 7 , R 8 and R 21 are the same as defined above for formula (28), n is an integer in the range of 0 to 5, R 22 independently represents a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, a C 2 -C 4 straight-chain or branched haloalkenyl group, a hydroxyl group, a C 2 -C 4 alkoxy group, an amino group, a carboxyl group, an ester group, a carbonyl group or a halogen atom, and m is an integer in the range of 0 to 8; and,
[0076] compounds represented by the following formula (31):
[0077] wherein R 7 , R 8 , R 21 and R 22 are the same as defined above for formulae (28) and (30), and n is an integer in the range of 0 to 5, and m is an integer in the range of 0 to 8.
[0078] As examples of the unsaturated compound of the above formula (12), there can be mentioned those which are represented by the following formulae (32) through (35).
[0079] Compounds represented by the following formula (32):
[0080] wherein R 7 and R 8 independently represent a hydrogen atom, a halogen atom, a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, or a C 2 -C 4 straight-chain or branched haloalkenyl group, and R 21 independently represents a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, a C 2 -C 4 straight-chain or branched haloalkenyl group, a hydroxyl group, a C 1 -C 4 alkoxy group, an amino group, a carboxyl group, an ester group, a carbonyl group or a halogen atom, and n is an integer in the range of 0 to 8;
[0081] compounds represented by the following formula (33):
[0082] wherein R 7 , R 8 and R 21 are the same as defined above for formula (32), and n is an integer in the range of 0 to 8;
[0083] compounds represented by the following formula (34):
[0084] wherein R 7 , R 8 and R 21 are the same as defined above for formula (32), n is an integer in the range of 0 to 5, R 22 independently represents a C 1 -C 4 straight-chain or branched alkyl group, a C 2 -C 4 straight-chain or branched alkenyl group, a C 1 -C 4 straight-chain or branched haloalkyl group, a C 2 -C 4 straight-chain or branched haloalkenyl group, a hydroxyl group, a C 1 -C 4 alkoxy group, an amino group, a carboxyl group, an ester group, a carbonyl group or a halogen atom, and m is an integer in the range of 0 to 8; and,
[0085] compounds represented by the following formula (35):
[0086] wherein R 7 , R 8 , R 21 and R 22 are the same as defined above for formulae (32) and (34), and n is an integer in the range of 0 to 8, and m is an integer in the range of 0 to 8.
[0087] Among the unsaturated compounds of formula (13), 2-methyleneadamantane represented by the following formula (37) is especially preferable.
[0088] In R 7 , R 8 and R 19 to R 22 of the above formulae (7) to (35), the terms “C 1 -C 4 straight-chain or branched haloalkyl group” and “C 2 -C 4 straight-chain or branched haloalkenyl group” mean a C 1 -C 4 straight-chain or branched alkyl group and a C 2 -C 4 straight-chain or branched alkenyl group, each having one or more halogen substituents, respectively. The halogen substituent includes chlorine, bromine, iodine and fluorine. The term “halogen atom” in R 7 , R 8 and R 19 to R 22 of the formulae (7) to (35) means chlorine, bromine, iodine and fluorine atoms.
[0089] The unsaturated compounds of formulae (2) and (3) used in the process of the present invention can be easily prepared, for example, by a method wherein a commercially available corresponding tertiary alcohol is subjected to intramolecular dehydration reaction, or a method wherein a commercially available corresponding carbonyl compound is subjected to Wittig reaction.
[0090] The amount of the unsaturated compound of formula (2) or (3) used in the process of the present invention is not particularly limited, but is preferably in the range of 1 mol to 20 mols per mol of the acrylic acid compound (1). When the amount of the unsaturated compound is too small, the conversion of the acrylic acid compound tends to be poor. In contrast, when the amount of the unsaturated compound is too large, the production cost is liable to be increased because many unsaturated compounds including 2-methyleneadamantane are expensive.
[0091] When the acrylic acid compound of formula (1) is allowed to react with the unsaturated compound of formula (2) or (3) by the process of the present invention, the acrylate compound of formula (4) can be produced with an enhanced efficiency. Especially when an acrylic acid compound represented by the following formula (38):
[0092] wherein R 6 is a hydrogen atom, a fluorine atom, an alkyl group (preferably a C 1 -C 4 straight-chain or branched alkyl group), an alkenyl group (preferably a C 2 -C 4 straight-chain or branched alkenyl group), a fluoroalkyl group (preferably a C 1 -C 4 straight-chain or branched fluoroalkyl group), or a fluoroalkenyl group (preferably a C 2 -C 4 straight-chain or branched fluoroalkenyl group), is allowed to react with 2-methyleneadamantane represented by the following formula (37):
[0093] a methyladamantyl acrylate compound represented by the following formula (40) can be produced with greatly enhanced efficiency.
[0094] wherein R 6 is the same as defined above for formula (38).
[0095] This makes a striking contrast with the conventional process wherein a methyladamantyl acrylate compound having a fluoroalkyl group such as 2-methyl-2-adamantyl α-trifluoromethylacrylate (MAFAC) is produced in a low yield.
[0096] The reaction of the acrylic acid compound of formula (1) with the unsaturated compound of formula (2) or (3) can be carried out in the presence of a catalyst to more enhance the efficiency. The catalyst is preferably an acidic catalyst, which includes, for example, hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, nitric acid, phosphoric acid, sulfonic acid compounds, carboxylic acid compounds and Lewis acid compounds.
[0097] By the term “sulfonic acid compounds” used herein, we mean catalysts having a sulfonic acid group in the molecule structure. The sulfonic acid compounds are not particularly limited provided that they have a sulfonic acid group, and, as specific examples thereof, there can be mentioned inorganic sulfonic acids such as sulfuric acid, fluorosulfonic acid and chlorosulfonic acid; aliphatic sulfonic acids such as methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, allylsulfonic acid, butanesulfonic acid, pentanesulfonic acid, hexanesulfonic acid, heptanesulfonic acid, octanesulfonic acid, nonanesulfonic acid, decanesulfonic acid, dodecanesulfonic acid, tetradecanesulfonic acid and DL-camphor-10-sulfonic acid; substituted aliphatic sulfonic acids such as trifluoromethanesulfonic acid, aminomethanesulfonic acid, 2-bromoethanesulfonic acid, 2-(N-morpholino)ethanesulfonic acid, N,N′-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, N-(acetamido)-2-aminoethanesulfonic acid, N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid, N-cyclohexyl-2-aminoethanesulfonic acid, 3-aminopropanesulfonic acid, N-cyclohexyl-2-hydroxy-3-aminopropanesulfonic acid, 3-chloro-2-hydroxypropanesulfonic acid, 3-(N-morpholino)propanesulfonic acid, 2-hydroxy-3-morpholinopropanesulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid, 2-amino-5-methylbenzene-1-sulfonic acid, methallylsulfonic acid and taurine; aromatic sulfonic acids such as benzenesulfonic acid, p-chlorobenzenesulfonic acid, p-phenolsulfonic acid, guaiacol-4-sulfonic acid, p-styrenesulfonic acid, phenylhydrazine-p-sulfonic acid, 1,2-benzenedisulfonic acid, 1,3-benzenedisulfonic acid, 1,4-benzenedisulfonic acid, m-toluenesulfonic acid, p-toluenesulfonic acid, 2,4-dimethylbenzenesulfonic acid, 2,5-dimethylbenzenesulfonic acid, 2-mesitylenesulfonic acid, p-ethylbenzenesulfonic acid, 3,5-dichloro-2-hydroxybenzenesulfonic acid, 2,4,6-trinitrobenzenesulfonic acid, o-aminobenzenesulfonic acid, m-xylidine-6-sulfonic acid, 4-amino-2-methylbenzene-1-sulfonic acid, 4-amino-5-methoxy-2-methylbenzenesulfonic acid, 4-amino-2-chlorotoluene-5-sulfonic acid, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 2,6-naphthalenedisulfonic acid, 2,7-naphthalenedisulfonic acid, 1-naphthol-2-sulfonic acid, 1-naphthol-4-sulfonic acid, 1-naphthol-8-sulfonic acid, 2-naphthol-6-sulfonic acid, 2-naphthol-3,6-disulfonic acid, 1-naphthylamine-4-sulfonic acid, 1-naphthylamine-6-sulfonic acid, 1-naphthylamine-8-sulfonic acid, 2-naphthylamine-1-sulfonic acid, 2-naphthylamine-6-sulfonic acid, 2,3-dihydroxynaphthalene-6-sulfonic acid, 2-amino-5-naphthol-7-sulfonic acid, 8-amino-1-naphthol-3,6-disulfonic acid, 8-aminonaphthalene-1,3,6-trisulfonic acid, 8-anilino-1-naphthalenesulfonic acid, 4,4′-diaminostilbene-2,2′-disulfonic acid, 7-iodo-8-hydroxyquinoline-5-sulfonic acid, diphenylamine-4-sulfonic acid, 1-pyrenesulfonic acid and sulfanilic acid; and sulfonic acid type cation-exchange resins such as Nafion (available from Du Pont Co.), sulfonic acid type Amberlist (available from Rohm & Haas Co.), sulfonic acid type Amberlite (available from Rohm & Haas Co.), sulfonic acid type Diaion (available from Mitsubishi Chem. Corp.), sulfonic acid type Duolite (available from Sumitomo Chem. Co.), sulfonic acid type Dowex (available from Dow Chem. Co.), sulfonic acid type Purolite (available from Purolite Co.) and sulfonic acid type Lewatit (available from Bayer AG).
[0098] By the term “carboxylic acid compounds” used herein, we mean catalysts having a carboxylic acid group in the molecule structure. The carboxylic acid compounds are not particularly limited provided that they have a carboxylic acid group, and, as specific examples thereof, there can be mentioned aliphatic carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, pelargonic acid, capric acid, n-undecylenic acid, acrylic acid, crotonic acid, isocrotonic acid, vinylacetic acid, methacrylic acid, angelic acid, tiglic acid, 2-pentenoic acid, 3-pentenoic acid, 4-pentenoic acid, α-ethylacrylic acid, β,β-dimethylacrylic acid, 2-hexenoic acid, 3-hexenoic acid, 4-hexenoic acid, 5-hexenoic acid, 2-methyl-2-pentenoic acid, 3-methyl-2-pentenoic acid, 4-methyl-2-pentenoic acid, 4-methyl-3-pentenoic acid, 2-heptenoic acid, 2-octenoic acid, 4-decenoic acid, 9-decenoic acid, 9-undecenoic acid, 10-undecenoic acid, 4-dodecenoic acid, 5-dodecenoic acid, propiolic acid, tetrolic acid, ethylpropiolic acid, n-propylpropiolic acid, isopropylpropiolic acid, n-butylpropiolic acid, t-butylpropiolic acid, n-amylpropiolic acid, 9-undecynoic acid, 2,4-pentadienoic acid, 2,4-hexadienoic acid, fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromoacetic acid, dibromoacetic acid, tribromoacetic acid, iodoacetic acid, diiodoacetic acid, triiodoacetic acid, α-chloropropionic acid, β-chloropropionic acid, α-bromopropionic acid, β-bromopropionic acid, α-iodopropionic acid, β-iodopropionic acid, α-chloroacrylic acid, β-chloroacrylic acid, trichloroacrylic acid, α-bromoacrylic acid, β-bromoacrylic acid, α-iodoacrylic acid, β-iodoacrylic acid, α-chlorocrotonic acid, β-chlorocrotonic acid, γ-chlorocrotonic acid, α-bromocrotonic acid, β-bromocrotonic acid, γ-bromocrotonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, chloromalonic acid, dichloromalonic acid, bromomalonic acid, dibromomalonic acid, chlorosuccnic acid, dichlorosuccnic acid, bromosuccnic acid, dibromosuccnic acid, methylsuccnic acid, methylenemalonic acid, α-methylglutaric acid, β-methylglutaric acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, trans-transmuconic acid, cis-cismuconic acid, cis-transmuconic acid, acetylenedicarboxylic acid, 1-propylene-1,3-dicarboxylic acid, 1-butyne-1,4-dicarboxylic acid, 2-butyne-1,4-dicarboxylic acid, propane-1,2,3-tricarboxylic acid and butane-1,2,3,4-tetracarboxylic acid; and aromatic carboxylic acids such as benzoic acid, o-hydroxybenzoic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 4-acetylbenzoic acid, o-fluorobenzoic acid, phthalic acid, 1,2,4,5-benzenetetracarboxylic acid, 1-naphthoic acid, 2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4-biphenylcarboxylic acid, 4,4′-biphenyldicarboxylic acid, 9-anthracenedicarboxylic acid, 2-quinolinecarboxylic acid and 4-pyridinecarboxylic acid.
[0099] As specific examples of the Lewis acid compounds used as a catalyst in the present invention, there can be mentioned boron trifluoride, boron trichloride, boron tribromide, aluminum chloride, aluminum bromide, iron(III) chloride, iron(III) bromide, antimony trichloride, antimony pentachloride, titanium trichloride, titanium tetrachloride, zinc chloride, zinc bromide, tin chloride, copper chloride, tungsten chloride, iron powder and zeolites.
[0100] Among the above-recited catalysts, sulfonic acid compounds such as sulfuric acid and p-toluenesulfonic acid are preferable. Sulfuric acid is especially preferable in view of safety and cost.
[0101] The catalysts may be used either alone or as a mixture of at least two thereof.
[0102] The amount of the catalyst is not particularly limited, but is usually in the range of 10 −4 mol to 1 mol per mol of the acrylic acid compound of formula (1).
[0103] In a preferable example of the process of the present invention, an acrylate compound represented by the following formula (41):
[0104] wherein R 6 is a hydrogen atom, a methyl group or a trifluoromethyl group, and R 23 is 2-methyl-2-adamanthyl group or a 1-methylcyclohexyl group, is produced by allowing an acrylic acid compound represented by the following formula (38):
[0105] wherein R 6 is the same as defined above for formula (41), to react with 2-methyleneadamantane or 1-ethylcyclohexene, represented by the following formula (37) or (36), respectively:
[0106] in the presence of an acid catalyst comprised of sulfuric acid or p-toluenesulfonic acid.
[0107] The reaction temperature is not particularly limited, but is usually in the range of −50° C. to 100° C.
[0108] The process of the present invention can be carried out in the presence of a solvent. The solvent used is not particularly limited, and, as specific examples thereof, there can be mentioned aliphatic hydrocarbons such as hexane and heptane; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as dichloromethane and dichloroethane; and ethers such as diethyl ether and tetrahydrofuran.
[0109] After completion of the reaction, the residual raw materials and catalyst are removed, for example, by washing a reaction mixture with water, and the object acrylate compound can be obtained by conventional purification procedures such as distillation, recrystallization and column chromatography.
[0110] The invention will now be specifically described by the following examples that by no means limit the scope of the invention.
REFERENCE EXAMPLE 1
Synthesis of 2-methyleneadamantane
[0111] One liter flask equipped with a Dean-Stark condenser was charged with 166.3 g (1.0 mol) of 2-methyl-2-adamantanol (supplied by Sigma-Aldrich Co.), 2.0 g (20 mmol) of sulfuric acid and 500 g of toluene. The content was heated to the solvent reflux temperature. While toluene and water produced through the reaction were collected as an azeotrope by the Dean-Stark condenser, the reaction mixture was refluxed for 2 hours. After completion of the reaction, the catalyst was removed by washing the reaction mixture with water and the obtained organic phase was concentrated to dryness to give 152.5 g of white solid 2-methyleneadamantane (purity: 99.0%, yield: 98.0%).
EXAMPLE 1
Synthesis of 2-methyl-2-adamantyl α-trifluoromethylacrylate [MAFAC]
[0112] A 500 ml flask was flushed with nitrogen to displace the air with nitrogen, and was charged with 70.0 g (0.50 mol) of α-trifluoromethylacrylic acid (supplied from Tosoh F-tech Inc.), 1.0 g (10 mmol) of sulfuric acid and 100 g of toluene. Separately 88.8 g (0.60 mol) of 2-methyleneadamantane, prepared by the same procedures as described in Reference Example 1, was dissolved in 100 g of toluene. The obtained solution of 2-methyleneadamantane in toluene was dropwise added to the content in the flask over a period of about 3 hours, while the content was maintained at a reaction temperature of about 5° C. Then the content was stirred for 15 hours at the same temperature. After completion of the reaction, the residual catalyst was neutralized by adding 40.0 g (50 mmol) of a 5% aqueous sodium hydroxide solution, and the neutralized liquid was washed with an aqueous saturated sodium chloride solution. The thus-obtained organic phase was subjected to column chromatography, and further, analyzed by NMR and mass spectrometry. Thus, 133.9 g (yield: 93.0%) of the object 2-methyl-2-adamantyl α-trifluoromethylacrylate was obtained.
[0113] Results of Analysis:
[0114] (1) 1 H-NMR (CDCl 3 ): δ(ppm)=6.73(1H,S), 6.42(1H,S), 1.63-2.43(15H,m)
[0115] (2) MS spectrum (m/z): 288(M+)
EXAMPLE 2
Synthesis of 2-methyl-2-adamantyl Acrylate [MAAC]
[0116] A 500 ml flask was flushed with nitrogen to displace the air with nitrogen, and was charged with 36.0 g (0.50 mol) of acrylic acid, 0.5 g (5 mmol) of sulfuric acid and 100 g of toluene. Separately 88.8 g (0.60 mol) of 2-methyleneadamantane, prepared by the same procedures as described in Reference Example 1, was dissolved in 100 g of toluene. The obtained solution of 2-methyleneadamantane in toluene was dropwise added to the content in the flask over a period of about 3 hours, while the content was maintained at a reaction temperature of about 20° C. Then the content was stirred for 5 hours at the same temperature. After completion of the reaction, the residual catalyst was neutralized by adding 40.0 g (50 mmol) of a 5% aqueous sodium hydroxide solution, and the neutralized liquid was washed with an aqueous saturated sodium chloride solution. The thus-obtained organic phase was subjected to column chromatography, and further, analyzed by NMR and mass spectrometry. Thus, 100.7 g (yield: 91.5%) of the object 2-methyl-2-adamantyl acrylate was obtained.
EXAMPLE 3
Synthesis of 2-methyl-2-adamantyl Methacrylate [MAMC]
[0117] A 500 ml flask was flushed with nitrogen to displace the air with nitrogen, and was charged with 43.0 g (0.50 mol) of methacrylic acid, 0.95 g (5 mmol) of p-toluenesulfonic acid monohydrate (supplied by Wako Pure Chem. Ind. Ltd.) and 100 g of toluene. Separately 74.0 g (0.50 mol) of 2-methyleneadamantane, prepared by the same procedures as described in Reference Example 1, was dissolved in 100 g of toluene. The obtained solution of 2-methyleneadamantane in toluene was dropwise added to the content in the flask over a period of about 3 hours, while the content was maintained at a reaction temperature of about 5° C. Then the content was stirred for 5 hours at the same temperature. After completion of the reaction, the residual catalyst was neutralized by adding 40.0 g (50 mmol) of a 5% aqueous sodium hydroxide solution, and the neutralized liquid was washed with an aqueous saturated sodium chloride solution. The thus-obtained organic phase was subjected to column chromatography, and further, analyzed by NMR and mass spectrometry. Thus, 106.2 g (yield: 90.8%) of the object 2-methyl-2-adamantyl methacrylate was obtained.
REFERENCE EXAMPLE 2
Synthesis of 1-ethylcyclohexanol
[0118] One liter flask was flushed with nitrogen to displace the air with nitrogen, and was charged with 26.7 g (1.1 mol) of metallic magnesium (supplied by Aldrich Co.) and 500 g of tetrahydrofuran. Among 109.0 g (1.0 mol) of ethyl bromide (supplied by Kanto Chem. Co.), about 5 g thereof was added to the content in the flask to confirm heat generation due to initiation of the exothermic Grignard reaction, and then the remainder of ethyl bromide was dropwise added over a period of about 1 hour while the inner temperature was controlled so as not to exceed 50° C. Further, the reaction mixture was stirred at the same temperature for 1 hour. Then, 98.2 g (1.0 mol) of cyclohexanone was dropwise added over a period of about 3 hours while the reaction temperature was controlled so as not to exceed 20° C. Further, the reaction mixture was stirred at the same temperature for 1 hour. After completion of the reaction, the reaction mixture was treated with 550 g (1.5 mol) of an aqueous HCl solution and the obtained organic phase was concentrated to dryness to give 127.6 g of a white solid. NMR and mass spectroscopy of the white solid revealed that it was 1-ethylcyclohexanol (purity: 98.5%, yield: 98.0%).
REFERENCE EXAMPLE 3
Synthesis of 1-ethylcyclohexene
[0119] One liter flask equipped with a Dean-Stark condenser was charged with 64.1 g (0.5 mol) of 1-ethylcyclohexanol, prepared in Reference Example 2, 1.0 g (10 mmol) of sulfuric acid and 300 g of toluene. The content was heated to the solvent reflux temperature. While toluene and water produced through the reaction were collected as an azeotrope by the Dean-Stark condenser, the reaction mixture was refluxed for 1 hours. After completion of the reaction, the catalyst was removed by washing the reaction mixture with water and the obtained organic phase was distilled under reduced pressure to obtain 58.3 g of colorless liquid as a fraction of 77° C./15 kPa. NMR and mass spectroscopy of the colorless liquid revealed that it was 1-ethylcyclohexene (purity: 96.0%, yield: 87.5%).
EXAMPLE 4
Synthesis of 1-ethylcyclohexyl Methacrylate
[0120] A 500 ml flask was flushed with nitrogen to displace the air with nitrogen, and was charged with 43.0 g (0.5 mol) of methacrylic acid, 0.5 g (5 mmol) of sulfuric acid and 100 g of toluene. Separately 110.2 g (1.0 mol) of 1-ethylcyclohexene, prepared by the same procedures as described in Reference Example 3, was dissolved in 100 g of toluene. The obtained solution of 1-ethylcyclohexene in toluene was dropwise added to the content in the flask over a period of about 3 hours, while the content was maintained at a reaction temperature of about 30° C. Then the content was stirred for 15 hours at the same temperature. After completion of the reaction, the residual catalyst was neutralized by adding 40.0 g (50 mmol) of a 5% aqueous sodium hydroxide solution, and the neutralized liquid was washed with an aqueous saturated sodium chloride solution. The thus-obtained organic phase was subjected to column chromatography, and further, analyzed by NMR and mass spectrometry. Thus, 68.6 g (yield: 69.9%) of the object 1-ethylcyclohexyl methacrylate was obtained.
[0121] Results of Analysis:
[0122] (1) 1 H-NMR (CDCl 3 ): δ(ppm)=6.12(1H,S), 5.55(1H,S), 1.25-2.37(15H,m), 0.89(3H,t)
[0123] (2) MS spectrum (m/z): 196(M+)
COMPARATIVE EXAMPLE 1
Synthesis of 2-methyl-2-adamantyl α-trifluoromethylacrylate [MAFAC] from 2-methyl-2-adamantanol and α-trifluoromethylacryloyl Chloride
[0124] A 500 ml flask was flushed with nitrogen to displace the air with nitrogen, and was charged with 83.1 g (0.50 mol) of 2-methyl-2-adamantanol, 101.2 g (1.0 mol) of triethylamine and 200 g of tetrahydrofuran. Then 118.9 g (0.75 mol) of α-trifluoromethylacryloyl chloride was dropwise added to the content in the flask over a period of about 1 hour, while the content was maintained at a reaction temperature of about 0° C. Then the content was stirred for 10 hours at room temperature. After completion of the reaction, the reaction mixture was washed with water and then with an aqueous saturated sodium chloride solution. The thus-obtained organic phase was subjected to column chromatography, and further, analyzed by NMR and mass spectrometry. Thus, 101.2 g (yield: 70.3%) of the object 2-methyl-2-adamantyl α-trifluoromethylacrylate was obtained. | An acrylate compound of formula (4):
is produced by allowing an acrylic acid compound of formula (1):
to react with an unsaturated compound of formula (2) or (3):
In formulae (1) through (4), R 1 and R 2 are H or F, R 3 is H, F, or an alkyl, alkenyl, fluoroalkyl or fluoroalkenyl group, R 4 and R 5 are H, halogen, or an alkyl, alkenyl, halogenated alkyl or halogenated alkenyl group; and X and Y are an unsubstituted or substituted hydrocarbon group, and dashed line - - - - - means that X and Y may be bonded together to form a cyclic structure. | 2 |
BACKGROUND OF THE INVENTION
The invention relates to a method and apparatus for separation of fluids by permeation in at least one permeation stage or cell provided with a wall which is differently permeable by such fluids or by their components, and which stage is subdivided by the wall into an inlet portion and a permeate portion, wherein the fluid is charged to that side of the membrane which is associated with the infeed portion and the less strongly permeating component is withdrawn at such side, while the more strongly permeating component is withdrawn at the permeate side.
The fluids involved herewith can be in the form of liquids, gases, solutions or dispersions. As a permeable wall, a membrane is used from a suitable material, e.g. of the type of a plastic film. To the known applications of such method belongs e.g. the separation of helium from natural gas. A method of this type can also be used in the field of enrichment with oxygen, with uranium or the like. In another application, it is possible, under the use of the principle of reverse osmosis, to separate salt components from seawater for the purpose of producing fresh water. For this purpose, a relatively high energy consumption is required as pressure values of between 50 and 100 bar must be generated.
All installations thus far used for such separation are relatively expensive with regard to their structure. A number of permeation stages in the form of membrane modules are interconnected in a cascade fashion. Such cascade interconnections, however, have the drawback that the required exchange surfaces must be relatively large and that, also, the drive of such installations is very demanding on energy. The reason for this is, among other things, the necessity of circulating relatively large volumes of fluid, namely with a great number of feeding organs or fluid movers.
Proceeding from the above, it is an object of the invention to provide a method suitable for separation of fluids by permeation which can be carried out in technically less expensive devices and at smaller operation costs.
SUMMARY OF THE INVENTION
In general terms and in one aspect thereof, the present invention provides a method for the separation of a fluid by permeation in at least one permeation stage which is provided with a wall differently permeable by the fluid or by its components, said stage being divided by the wall into an inlet portion and a permeate portion, the fluid being charged to that surface of the wall which is coincident with the inlet portion, a less readily permeating component of the fluid being withdrawn from said inlet portion while a more readily permeating component of the fluid is removed from the permeate portion as a permeate, wherein the permeate withdrawn from the permeate portion is partly circulated over a feeding device to the inlet portion while the less readily permeating component is withdrawn from the inlet portion.
In another aspect of the present invention and still defining same in general terms, an apparatus is provided for separation of fluids by permeation, of the type comprising, in combination: inlet chamber means communicating with inlet means for a fluid containing two components to be separated; partition means whose one surface forms a part of wall means of said inlet chamber and means made of a material more readily permeable by one of said components and less readily permeable by the other of said components; the other surface of the partition means forming a part of wall means of permeate chamber means; first discharge means communicating with said inlet chamber means and adapted to remove therefrom a portion of the fluid depleted in said one of said components; second discharge means communicating with said permeate chamber means for removal therefrom of a portion of the fluid enriched in said one of said components; circulation means including fluid mover means and communicating said permeate chamber means with said inlet chamber means for return of a portion of the fluid enriched in said one of said components from said permeate chamber means to said inlet chamber means.
In another aspect of the apparatus of the present invention and still referring to same in general terms, an apparatus is provided for separation of at least two components of a fluid from each other, comprising, in combination: a plurality of permeation cells disposed one after the other and comprising a first cell and a last cell; each cell comprising a container subdivided by a permeable wall into an inlet chamber and permeate chamber, said wall being of a predetermined permeability with respect to said at least two components; said inlet chambers being interconnected in series for fluid passage in a direction from said first cell to said last cell; said permeate chambers being interconnected in series for fluid passage in a direction from said last cell to said first cell; first discharge means for discharging fluid from the permeate chamber of the first cell; second discharge means for discharging fluid from the inlet chamber of the last cell; feeding means communicating with said series of the inlet chambers for feeding untreated fluid into said series of the inlet chambers at a predetermined location thereof; feedback means including fluid mover means and communicating the permeate chamber of the first cell with said series of the inlet chambers for feeding a part of the fluid from the permeate chamber to a predetermined location of said series.
Thus, in this method and apparatus, a concentration drops develops inside a permeation stage along the permeable wall such that the concentration in the permeate portion of the faster permeating components at one end of the wall is greater than at the other end of the wall. Therefore, the faster permeating component can be withdrawn from the permeate portion at this end of the wall at a relatively high concentration and can be partly charged back into the inlet portion for the continuing separation process, while another part of the withdrawn fluid is removed as an end product or an intermediate product for further separation steps.
The not so well permeating component of the fluid is withdrawn at the opposite end of the wall from the infeed portion and is also subjected to further separation treatments as a second end product or as an intermediate product.
The length of the permeable wall between the two end regions can be arbitrary and is determined in dependence on operational requirements.
The inventive method and apparatus is basically applicable also for the production of more than two end products or intermediate products as well as for more than two fluids or fluid components, each of a different concentration.
By the use of the inventive method, the costs required for the separation of fluids can be considerably reduced. For achieving predetermined separation performances, considerably smaller exchange surfaces are sufficient. Therefore, a correspondingly simplified structure of the apparatus results. Particularly in comparison with the known cascade installations, a smaller feeding capacity is necessary which leads to a correspondingly less rugged structure of the individual feeding organs and/or to a smaller number of same. A considerable saving in energy is achieved as well by the fact that in order to obtain the desired separation performance, smaller fluid volumes need to be conveyed.
In the following, several preferred embodiments of the invention will be described, of which particularly advantageous are those wherein a number of permeation stages is provided in which the inlet portions or chambers and the permeate portions or chambers are each connected one after the other. The respective required size of the exchange surfaces can thus be divided into different permeation stages which are connected in the proposed way.
Furthermore, it is proposed by the invention that the fluid between the inlet portions connected in series be charged to a location at which the concentration of the circulated fluid generally corresponds to the concentration of the charged untreated fluid components.
Referring respectively to a given separation rating, a further reduction is thus achieved of the fluid volume to be circulated. Also, the size of the required wall or exchange surfaces is further reduced. This is possible because, by the particular choice of the inlet point, the concentration within the device is distorted as little as possible.
It is further of advantage, in accordance with the invention, when two permeation stages are so connected with each other that the fluid flow which is not charged back into the inlet portion of the first permeation stage is directed to the inlet portion of the second permeation stage, while the fluid flow withdrawn from the inlet portion of the second permeation stage is charged back to the inlet portion of the first permeation stage.
By such doubling of the number of stages, admittedly, an additional fluid mover is generally required; however, this is more than compensated for by a substantially greater reduction of the fluid volume to be circulated. Also, the required exchange surface area is reduced.
A further advantageous embodiment of the method and apparatus of the invention resides in that two apparatus sections, each composed of a number of permeation stages connected in series, are so connected with each other that the fluid flow which is not charged back to the inlet portion of a permeation stage in the first section is charged back to an inlet portion of the second section disposed in a series, at a point at which the concentration of the circulated fluid generally corresponds to the concentration of the charged fluid components at the inlet portion of the said second section.
In so doing, firstly, the same advantages are achieved as have been described above for the use of the inventive method in merely a single apparatus section. Furthermore, in the two-section devices disposed in the described way, it is possible, if desired, to also withdraw, in a particularly advantageous way, a third product or an intermediate product at the end of the inlet portions of the second apparatus section arranged in series.
In this connection, it is further conceivable in accordance with the invention, that the fluid flow withdrawn from an inlet portion of the second apparatus section is charged back to an inlet portion of the first apparatus section connected in series with the former, at a point wherein the concentration of the circulated fluid in the inlet portions of the first apparatus section generally corresponds to the concentration of the components contained in the fluid flow.
A corresponding three- or more sectional arrangement of an apparatus, however, is also within the framework of the invention.
According to a further embodiment of the invention, the proposed method can also be carried out and the apparatus arranged such that the fluid flow withdrawn from the permeate portion of a first permeation stage is first charged back through the inlet portion of an additional stage and then into an inlet portion of the first permeation stage, and that the permeate is withdrawn from the permeate portion of the additional stage.
In such arrangement, the additional stage does not have to be so laid out as to provide along its permeable wall a drop in concentration. It has been found out that this arrangement of the inventive apparatus and method is particularly useful if especially high concentration values are to be achieved at least in an end product. These can be obtained in the described way with relatively very small exchange surfaces and low volume of the circulated fluid. It is conceivable with the arrangements associated with the inventive method or with the corresponding layout of the apparatus, that after achieving a given inlet concentration, a further increase in concentration achievable by such additional stage can be obtained by an exchange surface which is of a lesser size as compared with a further permeation stage connected correspondingly with the first permeation stage.
The final concentration can be increased in accordance with the invention by such a method or by a corresponding layout of the apparatus, in a further advantageous way, if the permeate portion of the auxiliary stage is connected with the infeed portion of a second auxiliary stage and if the end product is withdrawn from the permeate portion of the second auxiliary stage. Preferably, a further feeding organ is provided between the two auxiliary stages.
According to the invention, it is further possible to interconnect the apparatus sections utilizing an auxiliary stage such that the fluid flow withdrawn from the permeate portion of a first permeation stage or a first apparatus section is at least partly charged back over the inlet portion of an auxiliary stage into the inlet portion of the first permeation stage or into a first apparatus section, that the permeate obtained in the auxiliary stage is charged into the inlet portion of a second permeation stage or a second apparatus section, and that the component withdrawn from the last mentioned inlet section, which has a lesser capability to permeate, is charged into the inlet portion of the first permeation stage or of the first apparatus section. In so doing, the respective inlet locations in the series of inlet portions of an apparatus section can be so selected relative to the concentrations of the treated fluids and of the charged or withdrawn fluids, as has been described in connection with the method provisions referred to above. Further advantages are available, for certain applications of the proposed method, when the permeable walls of the respective permeation stages are provided with different permeability properties. In this context, it is further proposed in accordance with the invention that at least two permeation stages or apparatus sections be provided, each comprised of a number or permeation stages, and that the permeable walls comprised in the permeation stages or apparatus sections have different permeability features such that a stronger permeability is provided for each of the different components of the fluid. This can be implemented within the method proposed by the invention in a particularly suitable way, when two permeation stages or apparatus sections comprised of a number of permeation stages are provided with a first and a second permeability of the permeable walls such that for the respective different components of the fluid a stronger respective permeability is provided. The permeate portion of the permeation stage or of the apparatus section with the first permeability is then connected, over a fluid mover, with the infeed portion of the second permeation stage or of the second apparatus section having the second permeability. Also, in this embodiment, the permeate side of the second permeation stage or of the second apparatus section is maintained in connection, over a further fluid mover, with the inlet portion of the first permeation stage or of the first apparatus section. The respective product flows are withdrawn at the ends of the respective inlet portions or chambers.
This means, in other words, that within the framework of the carrying out of the proposed method in obtaining given concentration grades of the respective components of the fluid, a further increase in concentration can be obtained in the respective section whose permeable walls have the respective different permeability. Thus, it is also possible to obtain a considerable reduction in the respective fluid volume to be circulated.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in greater detail with reference to the accompanying drawings, wherein
FIG. 1 is a diagrammatic representation explanatory of the basic features of a permeation stage or cell used in the present invention;
FIG. 2 is a diagrammatic representation of a first embodiment of apparatus according to the invention;
FIG. 3 is a view similar to that of FIG. 2 of a second embodiment of apparatus according to the invention;
FIG. 4 is a view similar to that of FIG. 2 of a third embodiment of apparatus according to the invention;
FIG. 5 is a view similar to that of FIG. 2 of a fourth embodiment of apparatus according to the invention;
FIG. 6 is a view similar to that of FIG. 2 of a fifth embodiment of apparatus according to the invention; and
FIG. 7 is a view similar to that of FIG. 2 of a sixth embodiment of apparatus according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In all drawings, the letter F designates the inlet for the fluid to be treated. The component of the fluid which permeates more readily or the corresponding end product is referred to with A, while B designates the component or a further end product permeating less readily.
With reference to FIG. 1, the function of a permeation stage or cell 10 will be first described in general. A permeable or semipermeable wall or partition 11, subdivides the cell into an inlet portion or chamber 12 and a permeate portion or chamber 13. In the region of the upper end of the partition 11 in FIG. 1, the permeate, i.e. the component that passed through the wall or partition 11, is withdrawn by means of a fluid mover or pump 14 and is returned into the inlet chamber 12. During the course of circulation of the treated fluid contained in the permeation stage 10 and containining both components A and B, the following takes place:
A substantial volume of the more readily permeating component A passes through the wall 11 already at the upper region of the inlet chamber 12 of FIG. 1, so that the highest concentration in the component A will be obtained at the corresponding (i.e. upper) location of the permeate chamber 13. As the fluid proceeds to the lower end of the wall 11 in FIG. 1, the concentration in the component A within the inlet chamber 12 gradually decreases while the concentration of the component B correspondingly increase and reaches, at the lower end of the wall 11, its highest value. Therefore, the component B can be withdrawn at the bottom of chamber 12 as an end- or intermediate product (the withdrawal not being shown in FIG. 1), while the component A is withdrawn from the upper region of the permeate chamber 13.
By showing an interruption between the upper and the lower part of the permeation cell 10, reference is made to the fact that the length (i.e. the vertical size as viewed in FIG. 1) of the wall 11 can be arbitrarily selected to meet particular operational requirements.
In the apparatus shown in FIG. 2, the overall required exchange- or wall surface is divided into four permeation stages coincident with four cells 10. All inlet chambers 12 of the permeation cells 10 are connected in series in one direction and the permeate chambers 13 are connected in series in the opposite direction, so that a corresponding circulation of the treated fluid F results. It can be seen already from this embodiment that the apparatus suitable for carrying out the method can be produced by way of a modular assembly.
In this case, the fluid F to be treated is charged directly to the pressure side of the feeding organ or pump 14, while one end product A is withdrawn at the suction side of the pump 14 from the last one of the series of the permeate chambers 13. The other end product B is withdrawn at the last one of the series of the inlet chambers 12.
Alternatively, however, as is shown by the broken arrow F', it is possible to charge the fluid at such point of the series of the inlet portions 12, at which the concentration of the fluid components in circulation generally corresponds to the respective concentration in the yet untreated fluid F'. The concentration balance of the fluid in circulation is thus distorted as little as possible by the addition of this further volume of the untreated fluid. Thus smaller exchange surfaces and a reduced volume of the circulated fluid are required to obtain a predetermined separation capacity.
In FIG. 3 is shown an apparatus which is composed of two sections 15 and 16. Each of the sections corresponds in its basic arrangement to the apparatus shown in FIG. 2 in that each section 15 or 16 is provided with four permeation cells 10 and with a pump 14, respectively.
The fluid to be separated is introduced in the first section 15 into the series of its inlet chambers 12 at a point at which the concentration differences of the components in the circulated fluid and in the untreated incoming fluid are as small as possible. The fluid withdrawn by the pump 14 from the cell 10 having the last one of the series of the permeate chambers 13 is partly charged back into the first or top inlet chamber 12 of the small cell 10, while another part of the withdrawn fluid is introduced over a conduit 17 into the series of inlet chambers 12 of the second section 16, at a point at which the components A and B of the fluid circulated in section 16 are each of generally the same concentration as in the fluid flow coming from the conduit 17.
By a conduit 18, a fluid flow component is withdrawn at the end of the series of the inlet chambers 12 of the section 16 and is charged back into the series of inlet chambers 12 of the first section 15 at the same location at which the untreated fluid enters. Alternatively it is naturally also conceivable to connect the discharge end of conduit 18 in the region of the inlet chamber series of section 15 at another point, as may be suitable from the standpoint of concentration of the components A and B in the fluid components in the conduit 18 vis-a-vis the composition of fluid circulated in section 15 for assuring as a small difference in concentration at the inlet point as possible.
Thus, in the devices described in FIGS. 2 and 3, a fluid is charged into the device having a component A possessing a better permeating property and a component B which permeates less readily. In the apparatus according to FIG. 2, the obtained end product enriched in the component A is withdrawn at the end of the series comprised of the individual permeate chambers 13 or at the suction side of the fluid mover or pump 14, while the end product enriched in the component B is removed at the end of the series of the inlet chambers 12.
With reference to the withdrawal of the end product enriched in component B, the arrangement in FIGS. 2 and 3 is the same. However in the embodiment of FIG. 3 the end product enriched in the component A is withdrawn from the second section 16, namely again at the end of the series formed by the respective permeate chambers 13.
The following example illustrates the operation of the apparatus shown in FIG. 2.
It is an object to separate CO 2 from air. In the method, 10 mol/h of air with 0.1 mol components of CO 2 are to be separated such that 90% CO 2 and air with a 1% CO 2 residue are obtained.
The corresponding calculations reveal that a total exchange surface of 5.98 m 2 is required. The compression flow required for the fluid circulation amounts to 336 mol/h. Only one fluid mover is required.
If the same problem is to be solved with a known recycling cascade arrangement, a total exchange surface of 7.62 m 2 is necessary. Thus, the surface requirement is already notably greater than in the use of a device according to FIG. 2. In the known device, admittedly, the required compression flow is only 87.2 mol/h. However, a total of 10 fluid movers is required so that the total technical demand of the arrangement in FIG. 2 is considerably lower.
If a device according to FIG. 3 is used to solve the same problem, then further considerable improvements are achieved. Two fluid movers or compressors are admittedly required. However, the total compression flow is only 80 mol/h while the required exchange surface is only 2.26 m 2 . Thus, the exchange surface is smaller by 70.3% compared with the use of the device according to FIG. 2.
In both cases, CO 2 corresponds to the more readily permeating component A. Thus, the desired concentration is removed at the point marked with A.
On the other hand, the less readily permeating components of the air, particularly nitrogen and oxygen, correspond to the component of the fluid marked with B. Thus, air free of CO 2 will be withdrawn at the point marked B.
A further modification of the apparatus according to FIG. 3 is shown in FIG. 4. Here, an auxiliary third section 19 is shown whose arrangement corresponds to that of the sections 15 and 16. A comparison with the apparatus of FIG. 3 reveals the following:
The fluid withdrawn from the permeate chambers 13 of the second section 16 is partly introduced, over a further conduit 20, into the series composed of the inlet chambers 12 of the third section 19, again at a point at which the concentration of components of the incoming fluid flow corresponds to the concentration which is present at the inlet point of section 19. The end of the series formed by the inlet chambers 12 of the section 19 is connected, over a conduit 21, with the conduit 17 through which is conveyed a fluid flow component from the first section 15 to the second section 16. The concentration of fluid components withdrawn from the third section 19 over the conduit 21 is so determined that an as small as possible difference in the concentration of the corresponding components is present at the inlet point of the second section 16.
The end product correspondingly enriched in CO 2 in accordance with the problem is withdrawn at a point marked with A of the third section 19.
Despite an auxiliary use of a third fluid mover, a further reduction of the required expenses is attained when the enrichment limits given by the problem are considered as parameters.
FIG. 5 shows a further variation of an apparatus suitable for the carrying out of the proposed method. This one has section 15 of the layout corresponding to FIG. 3. The permeate withdrawn from the series of the permeate chambers 13 by means of the fluid mover 14 is now first charged into a first auxiliary stage or cell 22, namely to an inlet chamber 23 of the same. From there on, the corresponding fluid flow is directed to the series of inlet chambers 12 of the section 15. The more readily permeating component A passes through a permeable wall 24 of the auxiliary cell 22 and, in a first alternative can be withdrawn as an end product, already from the permeate chamber 25 of the auxiliary cell 22 as indicated by a broken arrow line A'. In this case, the permeate chamber 25 of the auxiliary cell 22 does not form a part of the fluid circulation as is typical for the permeation stages used in the known cascade arrangements. However, it has been found out that the use of such an additional permeation stage is of advantage in the region of higher concentration of the more readily permeating phase as a reduction of the required exchange area results. This is the case particularly when the permeate chamber 25 of the first auxiliary stage 22 is connected, over a further fluid mover 14, with a second auxiliary cell 26 corresponding in its structure to the auxiliary cell 22 and provided with a permeable wall 28 and a permeate chamber 29. The fluid flow induced in the inlet chamber 27 of the second auxiliary cell 26 can be charged back, over a conduit 30, to the inlet side of the inlet chamber 23 of the first auxiliary cell 22. Even though such a feedback may be provided within the framework of the foregoing example it is not absolutely necessary. It is to be established, by tests in a particular case extent to which such feedback can contribute to the achievement of further improvements.
In the above described example, the component A enriched in CO 2 is withdrawn from the permeate chamber 29 of the second auxiliary cell 26 which, like the permeate chamber 25 of the first auxiliary cell, is not included in a circulation.
In the last mentioned embodiment, it is within the framework of the above problem that, for the given CO 2 -concentration, only two fluid movers 14 or compressors are required. The compression flow is set at 49.1 mol/h, while the required exchange area amounts to only 1.9 m 2 .
A further embodiment of the inventive apparatus is shown in FIG. 6. Two sections 15 and 16 are provided, which are of the same structural arrangement as the respective sections of the previously described devices. Associated with each section 15 and 16 is a respective first auxiliary cell 22, namely in the same way as has been described for the first alternative according to FIG. 5 involving use of only one auxiliary cell. From the permeate chamber 25 of the auxiliary cell 22 which is connected downstream of the section 15, the permeate is removed. It arrives, over a further fluid mover 14 and a conduit 31, to the second section 16 where it is introduced into the series of the inlet chambers 12 at a point at which the concentration differences of the components are as low as possible. The downstream end of the series formed by the inlet chambers 12 of the section 16 is further connected, as in the embodiment of FIG. 3, over a conduit 18, with the first section 15, so that the removed less readily permeating component is introduced into the series formed by inlet chambers 12 of the first section 15, namely at the same point at which the introduction of untreated fluid takes place. The correspondingly enriched CO 2 or the component A is withdrawn from the permeate chamber 25 of the auxiliary cell 22 at the end of the second section 16.
In use of an apparatus thus structured a compression flow of 43.9 mol/h is obtained within the framework of the above problem, at an exchange surface of merely 1.78 m 2 , wherein three fluid movers 14 or compressors are required for the circulation of the fluid.
A further embodiment is shown in FIG. 7. A first section 32 contains two permeation cells 10, each with an inlet chamber 12, a permeate chamber 13 and a wall 11, which, similarly to all of the above described examples, is more readily permeable by the component A of the treated fluid flow.
A second section 33 has two permeation cells 34, each of which is provided with an inlet chamber 35, a permeate chamber 36 and with a permeable wall 37. The latter is so arranged, contrary to the wall 11, that it is more readily permeable by the component B.
In this case, the circulation is so arranged that the permeate chambers 13 of the permeation cells 10 of the first section 32, one fluid mover 14, and the inlet chambers 35 of the permeation cells 34 of the second apparatus section 33 are interconnected in series. Similarly, a series is formed from the permeate chambers 36 of the permeation cells 34, from a further fluid mover 14 and from the inlet chambers 12 of the permeation cells 10 in the first section 32. In detail, the following operation is then obtained.
The inlet of the untreated fluid flow composed of components A and B takes place in the region of the last mentioned series between the last permeate chamber 36 and the fluid mover 14. The component A permeates in both permeation stages 10 from the inlet chambers 12 into the permeate chambers 13 and passes from same over one of the fluid movers 14 into the inlet chambers 35 of the two permeation cells 34. On entry into the first inlet chamber 35, the fluid is already enriched to a substantial percentage in the component A; however, it still contains the component B. Since the partitions 37 of the permeation cells 34 are more readily permeable by the component B, the component B passes in both such permeation stages 34 into the permeate chambers 36, whereby the concentration of the component A in the inlet chambers 35 is further increased. The component A is then withdrawn as an end product at the end of the series formed from the two inlet chambers 35.
From both permeate chambers 36 of the permeation cells 34 forming the section 33, the fluid containing a large B component is directed, over the fluid mover 14, into the inlet chambers 12 of the permeation cells 10, from which, again, the component A can exit through the permeable walls 11. At the end of the series formed from the two inlet chambers 12, it is thus possible to withdraw the component B at its higher concentration.
With the method proposed by the invention, a number of separation problems can be solved. In the following, individual examples of applicability of the method are referred to both in the field of gas permeation as well as liquid permeation.
The following systems can be referred to as examples for the technical separation method taking place under permeation in gaseous phase:
separation of He, H 2 , O 2 , CO 2 , SO 2 , NH 3 from gaseous mixtures;
separation of saturated and unsaturated hydrocarbons;
purification of contaminated air or of exhaust gas;
CH 4 -enrichment in N 2 containing gases;
separation of nuclear fission gases;
separation of isotopes;
O 2 enrichment of air;
separation of H 2 from contaminated air;
removal of CO 2 from interior air.
The areas of application in the liquid permeation field are, for instance:
water separation from organic mixtures and vice versa;
separation of isomeric, azeotropic, thermally unstable mixtures, narrow boiling mixtures;
waste water purification.
Besides, valuable organic and inorganic components can be recovered or concentrated, for instance from water or the like carrier fluids (pharmaceutics).
Similarly to gas- or gel chromatography, a mixture can be quantitatively separated by the inventive method so that the method can also be used in testing techniques.
As is apparent from the foregoing description of the particular embodiments, numerous variations of the proposed method or of the corresponding layout of the apparatus are possible within the framework of the invention. In a particular case, naturally, for each separation problem respective technical and economic optimum values must be determined. This applies particularly with regard to the respective suitable or useful number of the feeding organs or compressors, as well as the magnitude of the particular compression flows and the overall exchange surface. Therefore, many further modifications of the aforesaid examples of the inventive method and apparatus exist which do not depart from the scope of the accompanying claims. | The separation of different components of a fluid, e.g. of He, H 2 , O 2 , or the like from gaseous mixtures, separation of saturated and unsaturated hydrocarbon, water separation from organic mixtures, waste water purification etc., is effected by passing the treated fluid over a row of permeation cells each formed by a container subdivided, by a wall more readily permeable by one component of the fluid, into an inlet chamber and a permeate chamber. The respective chambers are arranged in series directed opposite to each other and the respective products are withdrawn at the respective ends of the series. A part of the product of the permeate chamber series is fed back into the inlet chamber series. Preferably, the delivery of untreated fluid into the inlet chamber series is effected at a point selected such as to obtain the smallest possible difference in the concentration of a respective component in the incoming untreated fluid and in the fluid being circulated through the system. A number of combinations of the basic unit of the method is disclosed. The invention results in reduced energy and permeable area requirements by limiting the volume of recirculated fluid and by strategic location of the inlet for untreated fluid. | 1 |
BACKGROUND OF THE INVENTION
[0001] Aqueous adhesives have been widely used for bonding paper and plastic labels to glass and plastic surfaces. Bottle labeling adhesives are a subset of such aqueous adhesives. Labels are applied to beverage containers by high speed machines which transfer the adhesive to the label. Once coated with adhesive, the label is contacted with the container for permanent adhesion. Mechanical labeling via automated high speed machines requires the coordination of the criteria of numerous physical properties during the processing stage and, on the finished labeled product. During processing the adhesive must be capable of flowing, i.e., it should have a viscosity preferably within a range from about 20,000 to 200,000 mPas, have a high initial adhesion, which prevents undesired displacement of a freshly attached label on a base, and able to be processed on machines working with high-speed emulsions. Natural polymers such as starch and casein are often used as the base polymer in bottle labeling adhesives. Starch and casein based adhesives can be formulated to offer advantages such as machinability, high wet strength, and ice water resistance.
[0002] Recent ecological pressure has reversed the trend toward “non-returnable” bottles and reemphasized the need for “returnables”. As a result, many of the prior requirements for bottle labeling adhesives have been altered. One of the primary requirements for returnable bottles is that the labels be easily removed from the bottle prior to reutilization. The inability to remove the labels has made recently developed bottle labeling adhesives unacceptable for commercial operations. Casein based adhesives have been widely used since the dried adhesive film is responsive to caustic cleaning solutions. Starch based adhesives can also be used; however these adhesives are more difficult to clean with a caustic wash.
[0003] A current trend in the bottle industry is to use clear labels, and as such, they too impose new requirements of the adhesive. Many of the current adhesives which can be used in producing removable, clear bottle labels have the problem that they discolor (blush), when wet. Bottles often are placed in ice baths and, not only must the adhesives be ice-proof they also must be blush resistant. Adhesives, therefore, must possess an optimum balance in properties of being blush resistant, cold water resistant, and yet, allow the labels to be easily removed or stripped from the bottles.
[0004] Starch glues or dextrin glues have been widely used as adhesives for bottle labeling. However, they are not suited for producing blush resistant labels. Starch and ammonium salts of styrene-maleic anhydride resins have been used as they exhibit superior ice-proof properties. However, the bond formed by many of these adhesives is so strong that removal of the label, even upon soaking in hot alkaline water, is difficult or impossible.
[0005] Representative patents illustrating aqueous adhesive compositions useful for bottle labeling include:
[0006] U.S. Pat. No. 3,939,108 discloses a cold water resistant adhesive which has an optimum balance of cold water resistance and removability when employed for labeling of bottles. The adhesive comprises a mixture of starch, starch-maleic anhydride, peptizer, water and some alkali.
[0007] U.S. Pat. No. 4,462,838 discloses aqueous adhesives based upon starch derivatives for application in mechanical bottle labeling on high speed machines, particularly glass ware. The adhesives are comprised of a hydroxyalkyl ether of oxidized starch and a water-soluble synthetic polymer, casein or starch derivative. Examples of water-soluble polymers are polyvinyl pyrrolidone, vinyl acetate copolymers, and acrylic acid copolymers.
[0008] U.S. Pat. No. 5,455,066 discloses an aqueous adhesive based upon acid precipitated casein, water-soluble extenders, natural or synthetic resin acids, resin alcohols, and so forth for bottle labeling. Extenders are based upon copolymers of acrylic acid, acrylamides, starches, starch ethers and the like.
[0009] U.S. Pat. No. 6,590,031 discloses a pressure sensitive adhesive comprised of a polymer of an alkyl acrylate, carboxylic acid and styrene formed by polymerizing the monomers in the presence of an anionic surfactant and redox type free radical initiator. The polymers find use in clear label applications, making films, etc, and it is reported they exhibit excellent adhesion to hot water and enhanced resistance to water-whitening.
[0010] WO 03/029,378 discloses a water based adhesive that is suited for bonding plastic labels onto glass containers. The adhesive comprises a starch component and a gelatin compound.
[0011] WO 01/98422 discloses a water-based bottle labeling adhesive that promotes adhesion of paper or polysubstrates to plastic or poly-coated glass surfaces. The adhesive comprises from 30 to 80% of a synthetic base polymer, e.g., polyvinyl pyrrolidone, polyacrylic acid derivatives, carboxylated ethylene-vinyl acetate polymers, acrylic polymers, a tackifier, and additives and water. Examples of crosslinkers for the adhesives include zinc oxide, glyoxal and the like.
BRIEF SUMMARY OF THE INVENTION
[0012] This invention is directed to an improvement in acrylic based adhesives that are particularly suited for use in the application of paper and plastic labels onto glass surfaces, such as in bottle labeling. The base adhesive is comprised of an emulsion polymerized acrylic copolymer having acid functionality, e.g., carboxyl or sulfonic acid functionality; wherein the emulsion polymerization is carried out in the presence of a stabilizer system comprising a polymer containing polymerized units of carboxylic acid. The improvement for enhancing the blush resistance of the adhesive resides in incorporating a long chain crosslinking polyamine or polyamide selected from the group consisting of long chain aliphatic polyamines, cycloaliphatic diamines, particularly cyclohexane diamine, and cyclohexane derivates including oligomers of methylene bridged cyclohexane diamines, isophorone diamine, long chain polyamides, polyether polyamines, and the like. In this invention, the polyamides contain residual amines.
[0013] Significant advantages can be achieved in adhesives incorporating the polyamine additive and they include:
an ability to produce non blushing, very water resistant adhesive formulations for use in bottle labeling; an ability to yield water resistant, non blushing formulations for clear labels; an ability to produce very efficient, high viscosity formulations with excellent rheology and speed of set; and, an ability to produce clear labels which are removable in a caustic wash employed in bottle recycling.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Acrylic polymers have been used for producing removable bottle labeling adhesive formulations are generally all acrylic polymers polymerized in the presence of a styrene-carboxylic acid protective colloid or anionic surfactant with acid functionality polymerized therein. Alkyl esters of (meth)acrylic acid are incorporated into the polymer in various ratios and amounts. Representative alkyl esters of (meth)acrylic acid include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, methyl methacrylate, and the like.
[0019] Carboxyl functionality is incorporated into the adhesive polymer by polymerizing the alkyl esters of (meth)acrylic acid in the presence of a protective colloid of styrene/acrylic acid or via polymerization with acrylic acid or other carboxyl functional monomers. Examples of carboxylic monomers include methacrylic acid, itaconic acid, crotonic acid, and the like. Sulfonic acids can also be polymerized into the polymer, although it is preferred that carboxyl functionality be employed. These acrylate esters, although having a number of properties acceptable as adhesives for bottle labeling, suffer from low viscosity requiring blush resistant, viscosity building additives when applied to clear labels for glass bottles.
[0020] The acrylic bottle labeling polymers are formed by emulsion polymerization. Typically the styrene-carboxylic acid seed polymer, e.g., a styrene-acrylic acid, or styrene-maleic anhydride seed polymer is employed as a stabilizing agent. Alternatively an anionic surfactant or mixture of anionic surfactant and styrene-carboxylic acid polymer is used as a stabilizing system. A conventional styrene-carboxylic acid functional polymer generally incorporates from about 40 wt % to about 80 wt %, preferably from about 50 to 70 wt % styrene, based on the total weight of the monomer mixture.
[0021] Surfactants suitable for use in the forming the bottle labeling adhesive are anionic surfactants. Examples of anionic surfactants include ammonium salts of nonylphenol ethoxylated sulfates; lauryl ether sulfates or sulfosuccinates. A single anionic surfactant or mixture of anionic surfactants can be used. Typically, less than 4 wt % of the anionic surfactant based on the total weight of the latex, is used.
[0022] A redox type free radical initiator system often is used to promote polymerization of the acrylic ester monomers. The initiator is peroxide or hydroperoxide such as t-butyl hydroperoxide. The reducing agent used in the redox system is zinc formaldehyde sulfoxylate, sodium formaldehyde sulfoxylate, ascorbic acid, isoascorbic acid, sodium metabisulfite and the like. A preferred redox type system consists of t-butyl hydroperoxide and zinc formaldehyde sulfoxylate.
[0023] The aqueous latex emulsions, which form the basis of the adhesives of the present invention, are prepared in a single stage synthesis with or without a seed in the reaction vessel prior to beginning the monomer feed. Preferably the emulsion polymerization is carried out using a seed latex based upon a polymer of styrene and acrylic acid. Reaction temperatures during the monomer feed can range from about 50° C. to about 90° C.
[0024] Once the polymerization is complete it may be desirable to adjust the pH of the latex emulsion in order to enhance its stability. Ammonia addition is the preferred method of adjusting pH for the bottle labeling adhesives. Other ingredients commonly used in the preparation of aqueous latex emulsions such as buffering agents, chain transfer agents, and the like may be present. In addition to the aqueous latex emulsion, the bottle labeling adhesive may also contain additional components such as, biocides, wetting agents, defoamers, tackifiers, etc.
[0025] Other components which may be added to the aqueous adhesive formulations include natural or synthetic polymers such as starches or converted or modified starches, casein and synthetic polymers such as poly(vinyl pyrrolidone), poly(vinyl alcohol), acrylic acid containing water soluble dispersible acrylic polymers, thickeners, etc. However, starches and casein in even small amounts may lead to unacceptable blushing when the label is in contact with water. Thus, care must be exercised when adding starches and the like.
[0026] The improvement for improving the blush resistance of acrylic polymers commonly employed in bottle labeling applications are obtained by incorporating a small amount, i.e., from 0.25 to 5 weight parts, typically from 0.5 to 3 weight parts per 100 weight parts of the acrylic emulsion of a long chain, hydrophobic aliphatic polyamine or polyamide containing residual amines. Appropriate amines contain 6 to 25 carbons and include aliphatic polyamines, or cycloaliphatic polyamines, typically a cycloaliphatic diamine, aromatic polyamines, and long chain polyamides containing residual amines. Low molecular weight polyamines, particularly the polyalkylene polyamines, afford blush resistance but generally are too volatile and contribute to odor problems. Common amines are selected from the group consisting of polyethyleneimine, and cyclohexane diamine or derivatives thereof, such as methylcyclohexane diamine, methylene bridged cyclohexane diamines, including methylene di(4-cyclohexylamine), cyclohexyl propanediamine, isophorone diamine, and partial or full hydrogenated derivates of methylenedianiline.
[0027] Examples of commercially available amines or amides suitable for use in this invention are sold under the tradenames Anquamine®, Ancamide®, Anquamide®, and Ancamine® curing agents, available from Air Products and Chemicals, Inc.
[0028] Aliphatic and cycloaliphatic polyamines or polyamides are added generally in an amount of from 0.5 to 3 parts preferably from 1 to 2 weight parts per 100 weight parts of the emulsion based upon 50% polymer solids content in the emulsion or 0.25 to 2.5 parts (preferably 0.5 to 1 part) cycloaliphatic polyamine per 100 parts adhesive polymer. The addition of the amine or amide does at least two things; it replaces ammonia which is volatilized from the transparent label on drying and it provides for viscosity build of the final product. Prior to addition of the amine or amide, the viscosity of the bottle labeling acrylic emulsion may range from about 2000 to 3000 cps. On addition of the amine or amide, the viscosity may build to 10,000 to 200,000 cps. Typically, the viscosity varies with the amine or amide and the adhesive base. The viscosity requirements depend upon the type of label, the labeling machine, its speed and the environmental conditions. Thus, viscosities can range from 20,000 cps to 200,000 cps at 72° F., (22° C.); however they will generally be within the range of 20,000 cps and 100,000 cps. Viscosities can be measured with a Brookfield viscometer using the appropriate spindle at 20 RPM and 22° C.
[0029] Some of the long chain polyamines such as the meta-xylenediamine, the cycloaliphatic amines and, particularly the hydrogenated methylenedianiline derivatives result in very high viscosity builds. Often it is desired to blend these amines with other kinds of polyamines to achieve desirable blush resistance with acceptable viscosity. Usually, the desired upper level of the amine or amide is based upon the viscosity build. Some amines may be used at higher levels than others to reach the desired viscosity range.
[0030] Long chain amides, e.g. those formed by the reaction of C 6 to 20 carboxylic acids and polyethylene polyamines, such as triethylenetetramine and tetraethylenepentamine, may also be used, provided the amides contain residual amine.
[0031] Defoamers, preservatives, humectants, clay, masking agents, color agents and other modifying agents may be added without affecting the desirable properties of the adhesives of the invention. Thus, modifying agents such as wheat flour, bentonite, etc. may be employed for additional shortness and for machining requirements. Defoamers including tributyl phosphate, preservatives such as phenol, color agents like caramel and plasticizers and hygroscopic agents such as glycols, glycerine, and fatty acids may also be employed as required.
[0032] Virtually any commonly available label can be used with the adhesive compositions of the invention. Labels typically are prepared from thin sheet-like materials and can be made from a variety of materials including paper, polymer films, foil, film to polyester sheets, woven and nonwoven fabrics, and other sheet-like materials. Preferably labels formed of paper, polymer films or metallized polymers are used.
[0033] The following examples are provided to illustrate various embodiments and comparisons and are not intended to restrict the scope of the invention.
[0034] For film testing, a film was cast on a clean glass plate by using a 10 mil Bird bar applicator to apply a wet film of formulated emulsion to be tested. The film was allowed to dry 24 hours at room temperature and 50% relative humidity (RH) before testing. The film was visually inspected fro grit particles by holding the coated glass plate up to a light source and qualitatively evaluating the amount of dry grit particles present or by visually examining for streaking from the application process. The coated plate was then immersed for a specified time period into room temperature water and the amount of blushing was visually determined versus a control plate (coated with an unmodified polymer emulsion). The state of blush and the time of immersion were recorded. The designation for blush resistance varied from 1 for little blush to 4 for a lot of color. A blush value of 0-2 is preferred for clear labels.
[0035] Viscosities were measured with a Brookfield viscometer at 20 RPM and 22° C.
EXAMPLE 1
Styrene-Acrylate Bottle Labeling Adhesive
[0036] An acrylate polymer designed for commercial bottle labeling applications was prepared using 1300 g of a seed latex of a styrene/a-methyl styrene/acrylic acid (1:1:1 weight ratio) copolymer. The seed latex was added with agitation (150 rpm) to water (4030 g) in a 3 gallon reactor at room temperature. Aqueous ammonia (28 wt%, 315 g) was added slowly, and the resulting mixture was heated to 80° C. to effect dissolution of the copolymer. The pH of this solution was between 8.1 and 8.4. After the copolymer was dissolved, a solution of ammonium persulfate (31.5 g) in water (340 g) was added to the reactor and allowed to mix for 5 minutes.
[0037] A monomer delay consisting of 2-ethylhexyl acrylate (2100 g), butyl acrylate (2100 g) and styrene (525 g) was added to the reactor at a rate of 28.1 g/min for 60 minutes. At the 60 minute mark, the polymerization temperature was lowered to 75° C., and the monomer delay rate lowered to 16.3 g/min. The monomer delay was continued at this rate until it was completely added. At the 120-minute mark, additional water (810 g) was added to the polymerization at 5.8 g/min.
[0038] When the monomer delay was completed, residual monomer was rinsed from the monomer delay tube into the reactor by adding water (200 g) to the monomer delay tubes and feeding this water to the polymerization reactor. After the delay monomer and delay water feeds were finished, the reactor temperature was held at 75° C. for 30 minutes. The reaction mixture was then cooled to 50° C., and a solution of tert-butyl hydroperoxide (70 wt%, 21.1 g) in water (130 g) was added to the reactor. After mixing for 5 minutes, a solution of sodium erythorbate (14.6 g) in water (130 g) was added to the reactor. The reactor was then held at 50° C. for an additional 30 minutes to reduce monomer levels. After monomer levels were confirmed to be below 1000 ppm by gas chromatography, additional aqueous ammonia (28 wt%, 40 g) was added to the reactor and the final emulsion polymer (ca. 50% solids) was cooled to room temperature.
EXAMPLE 2
Evaluation of Amines as Blush Resistant Additives
[0039] A series of bottle labeling adhesive formulations was prepared using the acrylate emulsion of Example 1. The amines were added to the emulsion at levels of from 1 to 2 weight percent of the emulsion. Films were cast on glass plates and immersed in water. Blush resistance and polymer properties were measured. The results are shown in Tables 1 through 15.
TABLE 1 Parts 100 100 100 100 100 Polymer of Ex. 1 Parts IPDA 0 1 2 1 2 Film Clear Clear Clear Clear Clear Gritty No No No No No Viscosity 2110 5740 20650 5820 29900 Blush 1 min. 1 1 1 1 1 2 min. 2 2 2 2 1 3 min. 2 2 2 2 1 4 min. 2.5 2.5 2.5 2 2 5 min. 3 3 3 3 2.5 7.5 min. 4 4 4 4 2.5 10 min. 3 15 min. 4 IPDA = Isophorone diamine
[0040] Table 1 shows that the control, absent the addition of the cycloaliphatic diamine (isophorone diamine), affords reasonable and acceptable blush resistance, but the viscosity of the emulsion for bottle labeling is too low for some machines. Viscosity builders such as starch or casein, which are common additives, are unsuitable because they destroy the blush resistance of the bottle labeling polymer. Unacceptable blushing, e.g., greater than 4, can occur within 30 seconds to a few minutes.
[0041] Table 1 also shows that clear films with essentially no grit were formed when the cycloaliphatic diamine, isophorone diamine, was added to the acrylic adhesive. The viscosity increased at the 1 part level from that of the control where there was no diamine additive to a more favorable viscosity level at the 2 part level. Blush resistance at the 2 part level remained very good.
TABLE 2 Parts 100 100 100 100 100 Polymer of Ex. 1 Parts CHPD 0 1 2 1 2 Viscosity 2110 3180 6370 2900 3350 Film Clear Clear Clear Clear Clear Gritty No No No No No Blush 1 min. 1 1 1 1 1 2 min. 2 2 2 2.5 2 3 min. 2 2 2 2.5 2.5 4 min. 2.5 2.5 2 2.5 2.5 5 min. 3 3 2 3 3 7.5 min. 4 4 2 4 4 10 min. 2.5 15 min. 3 CHPD = cylcohexylpropane diamine
[0042] Table 2 shows that addition of cyclohexylpropane diamine additive provided excellent blush resistance, which was generally equal to or superior to the control, at the 1 and 2 part level. Viscosity build was modest but acceptable. It is believed the lower viscosity in relation to isophorone diamine is caused by the linear alkyl diamine portion. Blush resistance remains good.
TABLE 3 Parts Polymer of Ex. 1 100 100 100 Parts DEA 0 1 2 Viscosity 2110 2550 2310 Film Clear Clear Clear Gritty No No No Blush 1 min. 1 1 1 2 min. 2 1.5 2 3 min. 2 1.5 2 4 min. 2.5 1.5 2.5 5 min. 3 2.5 3 7.5 min. 4 3 4 10 min. 4 4 4 15 min. 4 DEA = diethylamine
[0043] Table 3 shows that blush resistance is quite good with the alkyl amine but viscosity build is quite limited. Diethylamine also suffers in industrial applications because of objectionable odor.
TABLE 4 Parts Polymer of Ex. 1 100 100 100 Parts TETA 0 1 2 Viscosity 2110 3010 3020 Film Clear Clear Clear Gritty No No No Blush 1 min. 1 1 1 2 min. 2 1 1 3 min. 2 2 2 4 min. 2.5 2.5 2.5 5 min. 3 2.5 3 7.5 min. 4 3 4 10 min. 4 4 4 15 min. 4 4 4 TETA = tetraethyltetramine
[0044] Table 4 shows triethylenetetramine resulted in good blush resistance as did diethylamine but it affords a slightly higher viscosity build. It is believed that linear polyethylene polyamines should have a higher molecular weight in order to achieve desirable viscosities.
TABLE 5 Parts Polymer of Ex. 1 100 100 100 Parts Anquamine 401 curing 0 1 2 agent Viscosity 2110 3270 4170 Film Clear Clear Clear Gritty No No No Blush 1 min. 1 1 1 2 min. 2 2 2 3 min. 2 1.5 1.5 4 min. 2.5 2 2 5 min. 3 2 2 7.5 min. 4 2.5 2.5 10 min. 4 3 3 15 min. 4 4 4 Anquamine 401 curing agent contains a modified tetraethylene pentamine adduct
[0045] Table 5 shows that the film containing the modified aliphatic amine has good blush resistance but poor viscosity build. These results also confirm the speculation that polyethylene polyamines of higher molecular weight are required to increase viscosity build.
TABLE 6 Parts Polymer of Ex. 1 100 100 100 Parts Ancamide 375A 0 1 2 Viscosity 2110 5600 10280 Film Clear Clear Clear Gritty No Very slight Slight 1 min. 1 1 1 2 min. 2 2 1 3 min. 2 2 2 4 min. 2.5 2.5 2.5 5 min. 3 2.5 2.5 7.5 min. 4 3 3 10 min. 4 4 4 Ancamide 375A curing agent contains a long chain polyamide
[0046] Table 6 shows that a long chain polyamide shows improved viscosity build compared to that of the polyamines employed in Tables 4 and 5. Blush resistance remains excellent.
TABLE 7 Parts Polymer of Ex. 1 100 100 100 Parts Jeffamine D230 0 1 2 Viscosity 2110 3050 3190 Film Clear Clear Clear Gritty No Slight Slight Blush 1 min. 1 0 0 2 min. 2 1 1 3 min. 2 1 1 4 min. 2.5 2 2 .5 min. 3 2 2.5 7.5 min. 4 2 2.5 10 min. 4 2 2.5 15 min. 4 2.5 3 20 min. 2.5 4 25 min. 3 4 30 min. 3 4 35 min. 3 40 min. 4 Jeffamine ® D230 contains poly(oxypropylene)diamine; supplied by Huntsman.
[0047] Table 7 shows the polyether polyamine offered excellent blush resistance but poor viscosity build. Higher level of polyether polyamines or higher molecular weight polyamines may be required.
TABLE 8 Parts Polymer of Ex. 1 100 100 100 Parts Ancamine 1922A 0 1 2 Viscosity 2110 3130 3200 Film Clear Clear Clear Gritty No Slight Slight Blush 1 min. 1 1 1 2 min. 2 1 1 3 min. 2 1.5 1.5 4 min. 2.5 2 2 5 min. 3 2 2 7.5 min. 4 2.5 2.5 10 min. 4 3 3 15 min. 4 4 3 Ancamine 1922A curing agent contains an unmodified glycol ether-based aliphatic amine
[0048] Table 8 shows the amine affords good blush resistance with only modest viscosity build. These ether polyamines (Tables 7 and 8) seem to offer similar viscosities to the low molecular weight polyethylene polyamines.
TABLE 9 Parts Polymer of Ex. 1 100 100 100 Parts Anquamine287 0 1 2 Viscosity 2110 5600 10280 Film Clear Clear Clear Gritty No Very slight Slight Blush 1 min. 1 1 1 2 min. 2 2 1 3 min. 2 2 2 4 min. 2.5 2.5 2.5 5 min. 3 2.5 2.5 7.5 min. 4 Anquamine 287 curing agent is a Mannich base amine adduct.
[0049] Table 9 shows that the use of this polyamine resulted in superior blush resistance compared to the control. Viscosity build is reasonably good and higher than the linear, lower molecular weight polyethylene polyamines (e.g., Table 3) and the glycol of Table 8.
TABLE 10 Parts Polymer of Ex. 1 100 100 100 Parts Epilink 701 0 1 2 Viscosity 2110 11580 162000 Film Clear Clear Clear Gritty No Slight Minor Blush 1 min. 1 1 1 2 min. 2 2 2 3 min. 2 2 2 4 min. 2.5 2.5 2.5 5 min. 3 2.5 2.5 7.5 min. 4 3 3 10 min. 4 4 Epilink 701 contains meta-xylenediamine; supplied by Air Products and Chemicals, Inc.
[0050] Table 10 shows that addition of meta-xylenediamine resulted in bottle labeling adhesives having excellent blush resistance but also resulted in high viscosity builds when going from 1 to 2 parts by weight of the emulsion. Some of the effect may be caused by the lower solubility of the aromatic amine in the emulsion than, for example, the linear polyethylene polyamines. These data also suggest that blends of the meta-xylenediamine with an amine such as cyclohexylpropane diamine (Table 2) may afford excellent blush resistance and tailored viscosity builds in the emulsion.
TABLE 11 Parts Polymer of Ex. 1 100 100 100 Parts Ancamine 2168 0 1 2 Viscosity 2110 6420 200000 Film Clear Clear Clear Gritty No Lumpy Slight Blush 1 min. 1 1 1 2 min. 2 2 2.5 3 min. 2 2 3 4 min. 2.5 2 3 5 min. 3 3 3 7.5 min. 4 4 4 10 min. 4 4 4 15 min. 4 4 4 Ancamine 2168 curing agent contains a mixture of partially hydrogenated methylenedianiline oligomers.
[0051] Table 11 shows that a partially hydrogenated mixture of methylenedianiline oligomers offers good blush resistance but also high viscosity build. This amine is difficult to incorporate into the emulsion. Table 12 shows the impact of dilution of this normally solid polyamine.
TABLE 12 Polymer of Ex. 1 100 100 100 Parts Ancamine 2168:IPDA 0 1 2 Viscosity 2110 11580 162000 Film Clear Clear Clear Gritty No Slight Minor Blush 1 min. 1 1 1 2 min. 2 2 2 3 min. 2 2 2 4 min. 2.5 2.5 2.5 5 min. 3 2.5 2.5 7.5 min. 4 3 3 10 min. 4 4 Ancamine 2168:IPDA is a 1:1 mixture of Ancamine 2168 curing agent and isophorone diamine.
[0052] Table 12 shows good blush resistance with lower viscosity than is shown with the partially hydrogenated mixture of methylenedianiline oligomers in Table 11. This example is important to show that these amines, in small amounts, afford blush resistance to acrylate bottle labeling adhesives and that viscosities within desired ranges can be achieved with appropriate blending without sacrificing blush resistance.
TABLE 13 Parts Polymer of Ex. 1 100 100 100 Parts Ancamide 503 0 1 2 Viscosity 2110 3100 4000 Film Clear Clear Clear Gritty No No No Blush 1 min. 1 0 0 2 min. 2 1 0 3 min. 2 1 0 4 min. 2.5 2 0 5 min. 3 2 0 7.5 min. 4 3 0 10 min. 4 4 0.5 15 min. 4 4 1 20 1.5 25 2 30 2.5 35 3 40 3 45 4 Ancamide 503 curing agent contains aliphatic polyalkylene polyamine-polyamide.
[0053] Table 13 shows the long chain polyamide offers excellent blush resistance but offers little viscosity build. Blush resistance was very good even at the 45 minute level (This sample was exposed for a longer period of time than other samples; some of the other amines may have performed as well if exposure continued.) The low viscosity build is somewhat surprising as it was thought viscosity should have been higher.
TABLE 14 Parts Polymer of Ex. 1 100 100 100 Parts Ancamide 350A 0 1 2 Viscosity 2110 3680 9940 Film Clear Clear Clear Gritty No Slight Slight Blush 1 min. 1 1 0 2 min. 2 2 1 3 min. 2 2 1 4 min. 2.5 2 1 5 min. 3 2 1.5 7.5 min. 4 3 2.5 10 min. 4 4 3 15 min. 4 4 4 Ancamide 350 A curing agent contains a polyamide having residual amines.
[0054] Table 14 shows that excellent blush resistance is achieved with better viscosity build than the amine of Table 13, although the amines were similar.
[0055] Although not intending to be bound by theory, it is believed that blush resistance is achieved by replacing an ammonia cation in a free film with a hydrophobic long chain diamine. This creates a hydrophobic area adjacent to the water sensitive acid group, e.g., carboxyl group, on the colloid by cationic neutralization. The diamines, unexpectedly, do not destabilize the emulsion, cause grit or undesirable aging effects. | This invention is directed to an improvement in acrylic based adhesives that are particularly suited for use in the application of paper and plastic labels onto glass surfaces, such as in bottle labeling. The base adhesive is comprised of an emulsion polymerized acrylic copolymer having acid functionality, e.g., carboxyl or sulfonic acid functionality; wherein the emulsion polymerization is carried out in the presence of a stabilizer system comprising a polymer containing polymerized units of carboxylic acid. The improvement for enhancing the blush resistance of the adhesive resides in incorporating a long chain crosslinking polyamine or polyamide containing residual amines. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of application Ser. No. 10/432,433, which is a 35 USC 371 application of PCT/DE 01/04386 filed on Nov. 23, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention is directed to a workpiece and more particularly to a plastically deformable workpiece for joining to another piece.
[0004] 2. Description of the Prior Art
[0005] So-called flared joints are known in which two workpieces are first slid one into the other so that the one workpiece rests against a stop of the other and protrudes above it with an edge, the flared edge. The joint is produced through flanging, the flaring, of the flared edge onto the one workpiece so that the workpieces are joined in a positively engaging manner. In this type of joint, two workpieces are required and it is only possible to achieve a definite contour of the flanging of the flared edge through costly measures. A flared edge must often be provided around the entire circumference of a workpiece. After the joining, there is thus often an axial and/or radial projection.
[0006] Another known type of joint is the so-called dovetail joint in which tolerances must be very strictly maintained. In the joining process, a projecting part and a recess of the dovetail joint are placed one over the other and are then pressed one into the other, as described in DE 39 25 365 A1. In the process of this, the parts must be placed one over the other and are not slid one into the other, thus rendering it necessary to make the parts that are to be connected somewhat longer and thus increasing the tolerance, for example of an inner diameter of a tube element.
[0007] DE 38 15 927 A1 has disclosed a joining of shaped parts by means of elastic securing arms. This design, however, inevitably leaves gaps between the shaped parts. It is not possible to produce a gap-free transition between the shaped parts.
[0008] U.S. Pat. No. 2,283,918 has disclosed a joining method for a metal band in which a tab is caulked into a recess. A bulky tool and powerful forces are required to produce the caulking.
[0009] U.S. Pat. No. 3,502,922 has disclosed a detent connection that is comprised of an insert tab and a recess. The insert tab is slid into the recess in order to produce a joint. The regions around the recess are designed to be elastic so that they can move outward and then spring back together when the insert tab is slid into the recess. This results in a certain amount of play between the parts.
[0010] Another possibility for mounting a ring onto an inner piece is the shrink-fitting technique. In this instance, the inner piece, for example, is cooled so that it shrinks. Only then can the ring be slid onto the inner piece. When the inner piece warms up again, a press fit is produced between the inner piece and the ring. The method, however, is costly and has the disadvantage that the joint comes apart if the ring and the inner piece cool or heat differently.
SUMMARY AND ADVANTAGES OF THE INVENTION
[0011] The workpiece according to the invention, has the advantage over the prior art that a workpiece can be simply mounted onto a component and there is no tolerance. After the joining process is complete, the workpiece has neither an axial nor a radial projection.
[0012] Advantageous modifications and improvements of the workpiece are also disclosed.
[0013] If the workpiece is a tube element, then it can advantageously be mounted onto an inner piece.
[0014] It is also advantageous for the recess to be designed similar to the shape of a dumbbell because this simplifies the plastic deformation for tolerance-free mounting.
[0015] The workpiece is advantageously comprised of metal because metal has a favorable capacity for plastic deformation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] An exemplary embodiment of the invention is described herein below, with reference to the drawings, in which:
[0017] FIG. 1 shows a detail of a workpiece according to the invention, in the unmounted state,
[0018] FIG. 2 shows a detail of a workpiece according to the invention, which is plastically deformed,
[0019] FIG. 3 a shows how the workpiece according to the invention is slid over an inner piece, and
[0020] FIG. 3 b shows how a workpiece according to the invention is mounted onto the inner piece.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] FIG. 1 shows a partial section of a workpiece 1 according to the invention. The workpiece 1 can be a sheet metal band extending along a longitudinal axis 2 or a sheet metal ring and has at least one aperture of recess 5 . The recess 5 , which is embodied for example with a circumferentially closed border, has the shape, for example, of a dumbbell or a spool.
[0022] It is possible for the recess 5 to have any other shape. The recess 5 is designed so that in a strip-shaped edge region 7 of the workpiece 1 , there is a greater empty volume 9 than in a middle region 8 of the recess 5 .
[0023] In the middle region 8 , there is a connecting segment 11 that extends perpendicular to the longitudinal axis 2 , which connecting segment 11 , in the direction of the longitudinal axis 2 , has a thickness or, if the recess 5 is circular, a diameter d, which is sized so that it is almost or completely compressed, i.e. becomes zero, when the workpiece 1 is mounted. The connecting segment 11 connects the one larger empty volume in one edge region 7 to the other larger empty volume in the other edge region 7 .
[0024] FIG. 2 shows a workpiece 1 according to the invention, which is plastically deformed. Starting with the workpiece 1 in FIG. 1 , a tool 12 is placed against it, for example in each edge region 7 , which tool exerts a force on the workpiece 1 in a deforming direction 13 lateral to the longitudinal axis 2 and compresses the empty volume 9 of the recess 5 . This causes the workpiece 1 to contract in the direction of the longitudinal axis 2 in a dimension, a joining direction 15 , perpendicular to the deforming direction 13 . The empty volume 9 and the connecting segment 11 are almost or completely gone, for example. Since an external force exerted by the tool 12 can only be applied in an edge region 7 of the workpiece 1 , it makes sense to design the recess 5 so that the greatest proportion of the empty volume 9 of the recess 5 is provided in this edge region 7 because then a plastic deformation requires only minimal forces and the plastic deformation can therefore be produced with considerable ease.
[0025] FIG. 3 a shows how a workpiece 1 is slid onto an inner piece 18 . For example, the workpiece 1 is a tube element 21 and the inner piece 18 is a coil body of an electric machine, the tube element 21 in this instance constituting a magnetic yoke element. In comparison to a two-part tube element with a continuous connecting point according to the prior art, the tube element according to the invention has the advantage that there is no gap-encumbered transition that interrupts the flow of the magnetic field in the yoke element.
[0026] The tube element 21 has an inner diameter that is greater than the outer diameter of the inner piece 18 . When the tube element 21 is plastically deformed by the tool 12 , the tube element 21 rests snugly against the inner piece 18 and is thus fastened to the inner piece 18 ( FIG. 3 b ).
[0027] FIG. 3 b shows a tube element 21 , which is fastened to an inner piece 18 . The tool 12 has deformed the tube element 21 , thus compressing the recess 5 . This causes the tube element 21 to contract in a joining direction 15 , i.e. in the case of the tube element 21 , the inner diameter of the tube element 21 becomes smaller. The plastic deformation is executed until the inner diameter of the tube element 21 approximately corresponds to the outer diameter of the inner piece 18 and is deformed even further so that a sufficient force is produced, which presses the tube element 21 onto the inner piece 18 .
[0028] The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims. | A workpiece according to the invention has a recess that is compressed by means of a plastic deformation, which reduces one dimension or an inner diameter of the workpiece and thus joins this workpiece to an inner piece in a positively and frictionally engaging manner. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2009-201597, filed on Sep. 1, 2009 the entire contents of which are incorporated herein by reference.
FIELD
[0002] The embodiments relate to a storage system including a storage device for storing data and a storage control device for controlling the storage device.
BACKGROUND
[0003] A storage control device such as a redundant arrays of inexpensive (independent) disks (RAID) device or the like includes a storage device such as a hard disk drive (HDD) or the like. Data is dispersed and stored in a plurality of storage devices in the RAID device. Therefore, when receiving an instruction from a host, the storage control device accesses a storage device in which corresponding data is stored. The storage control device and a storage medium such as an HDD or the like, which are included in the RAID device, construct a system that has redundancy. In addition, when a failure such as an abnormality or the like occurs in the storage device, the storage control device sends notification of the state to monitoring software through a serial port or a LAN.
[0004] FIG. 1 illustrates a configuration of the HDD. When receiving an instruction from the host, a micro processing unit (MPU) 2 in the storage control device performs a read/write processing operation for data by moving a head 3 to a data area in a disk 4 that is a storage medium in an HDD 1 . The disk 4 includes a plurality of cylinders 5 and a plurality of heads 3 , which are mounted concentrically, and includes a plurality of sectors 6 in the individual cylinders 5 . The position of a storage area is identified using a physical address based on the head 3 , the cylinder 5 , and the position of the sector 6 . On the other hand, in order to specify the storage area, the host uses a logical address that indicates a virtual position. In a system area 7 that is a specific area in the disk, logical address/physical address translation information, which is translation logic used for performing translation between a logical address and a physical address, and medium defect information are stored. The address translation information and the medium defect information will be described hereinafter. In the HDD 1 , when power is activated, the address translation information and the medium defect information are read out and written in a memory 8 . By referring to the address translation information and the medium defect information, written in the memory 8 , translation from the logical address to the physical address is performed. In this way, when the physical address of the indicated storage area is specified, a control section in the MPU 2 causes a voice-coil motor 9 to be driven, a head actuator 10 to be moved, and the head to be moved to a corresponding cylinder position. An HDD control section causes the head to be moved to the corresponding cylinder, waits for a corresponding sector to spin around and return, and performs a read/write processing operation using the head selected by a head selector. Data received from the host is written in a corresponding physical position. Data read out is sent to the host through the storage control device.
[0005] Here, the address translation information will be described. The address translation information includes a value indicating what number block from a first block indicated by the host an address corresponds to, and associates physical addresses indicating physical positions on a medium with logical addresses sequentially arranged, for example, from zero to a maximum value. When the HDD differs in type, the numbers of cylinders, heads, and sectors differ. In addition, in the HDD, when there is a defect on a storage medium and a corresponding portion is defined as unusable, a processing operation in which the corresponding portion is assigned to an alternate area and the defect position is not used is performed. A memory in the HDD stores a defect position information table which indicates the defect position. By referring to the defect position information table and the address translation information, while the defect position is skipped, data can be read or written.
[0006] In the related art, when, at the time data on a storage medium is accessed, a logical address indicated by a host is different from a physical address actually read or written, there occurs a problem in which data corruption arises or undesirable data is overwritten, and reliability is damaged. When a head selector is out of order, a head corresponding to a physical address obtained by translating a logical address from the host is not selected and a false head continues to be selected.
[0007] Continued failures such as physical failures of head selectors or the like account for the main factors of address mistranslation in the related art.
[0008] Therefore, there is adopted a method in which, when a data position indicated by the host is not normally translated into a data position where data is to be actually read or written, the mistranslation is detected. In the detection method of the related art, when user data is written, user data is written in one block with the addition of a logical address value indicating a logical address. In addition, when data is read, the added logical address value is compared with the address value indicated by the host at the time data is read. When the added logical address value matches the address value indicated by the host, it is determined that the read user data corresponds to data located at a correct position. Here, when the added logical address value does not match the address value indicated by the host, it is determined that the read user data corresponds to data located at an erroneous position, and the HDD informs the host or the storage control device of the presence of an abnormality. Accordingly, since interpolation can be performed using redundancy data of the RAID device, continued mistranslation can be resolved using the above-mentioned technique. In addition, when mistranslation is continued, a read/write processing operation is performed at an erroneous position both at the time data is written and at the time data is read. Since user data and a logical address value are newly written, it is determined that comparison of the logical address value at next read-in indicates normality. Since user data written in a corresponding area is also correct, no problem occurs.
[0009] Related patent documents are as follows: Japanese Laid-open Patent Publication No. 9-223366, Japanese Laid-open Patent Publication No. 2006-72435, and Japanese Laid-open Patent Publication No. 2003-228925.
[0010] In recent years, soft errors in a memory in an HDD have accounted for the main factors of address mistranslation. Soft error is a phenomenon in which defect position information written in the memory is destroyed. In storage control devices of recent years, a random access memory (RAM) has been manufactured so as to have a high density and a fine structure, in order to establish high capacity. Therefore, a soft error in which a bit is inverted owing to the influence of an alpha ray or a neutron ray has a high probability of occurrence.
[0011] A numerical value that is written in the memory and indicates a defect position is bit-inverted owing to the soft error and hence causes mistranslation. For example, when the third digit is bit-inverted in “0100” indicating that there is a defect in the fifth sector from “0”, “0000” turns out to be stored in the memory. Namely, since “0000” indicates that there is a defect in the first sector from “0”, a storage area which normally corresponds to the defect position and is not supposed to be accessed is accessed. This state is defined as an abnormal state.
[0012] Furthermore, since the soft error is not physical destruction of hardware, defect position information is read from a system area on a disk and rewritten in the memory, at the time power is activated owing to restart or the like. Owing to the rewrite processing operation, correct defect-position information is written. This state is defined as a normal state.
[0013] In this way, when the soft error occurs, the state transits from the normal state to the abnormal state and from the abnormal state to the normal state. When a write processing operation is performed during the state transition, an error is not reported from the HDD to the host or the storage control device. Therefore, data is left to be written in a storage area that is actually erroneous or data is written in a storage area in which data is not allowed to be written.
[0014] In the technique of the related art, in the case in which the state transits among three states, namely, from “normality” to “abnormality” and then to “normality”, even if a logical address value written along with user data is compared with a logical address value indicated from the host, the case in which the same address value is written occurs and hence the HDD does not report an error. Even if data, located at a position that is different from a normal position, is accessed, the data is not determined as abnormal and is transmitted to the host or the storage control device. Data corresponding to an instruction from the host is not obtained.
SUMMARY
[0015] According to an aspect of the invention, a storage control device for controlling the storage device including a medium for storing data, logical address information, and address translation information and a memory for storing the address translation information read from the medium includes a first receiver for receiving a write request including logical address information, a first sending module for sending a read request including the logical address information of the write request to the storage device, a second receiver for receiving data and logical address information stored in the medium in accordance with the read request from the storage device, and a second sending module for sending an instruction to cause the storage device to write the address translation information stored in the medium into the memory when the logical address information received by the second receiver is different from logical address information included in the write request.
[0016] The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims.
[0017] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1 is a configuration diagram of an HDD;
[0019] FIG. 2 is a hardware configuration diagram of a storage system in which a storage control device is used;
[0020] FIG. 3 is a firmware configuration diagram of a RAID device that is a storage control device;
[0021] FIG. 4 is a translation-information relationship diagram illustrating translation between logical addresses and physical addresses;
[0022] FIG. 5 is a diagram illustrating a correspondence relationship between logical addresses and physical addresses due to logical translation;
[0023] FIG. 6 is a transition diagram illustrating state transition from a normal state to an abnormal state in a case in which LBA values are added;
[0024] FIG. 7 is a state diagram illustrating the state of data in a case in which data is written in an abnormal state;
[0025] FIG. 8 is a state diagram illustrating the state of data in a case in which an rewrite processing operation for address translation information from a system area to a memory is performed owing to power reactivation for the HDD or the like;
[0026] FIG. 9 is a flowchart illustrating a write processing operation performed in the storage control device;
[0027] FIG. 10 is a flowchart illustrating a patrol processing operation; and
[0028] FIG. 11 is a flowchart illustrating a patrol processing operation in which a defect position is identified.
DESCRIPTION OF EMBODIMENTS
[0029] Embodiments of a storage control device, a storage system and a storage/reproduction method will be described in detail with reference to figures attached, hereinafter.
[0030] FIG. 2 illustrates a hardware configuration diagram of a storage system according to the embodiment. A RAID device 12 that is the storage control device includes a channel interface 13 that receives an instruction from a host 11 , a plurality of HDDs 1 that perform read/write operations for data, and a controller module 15 that controls the HDDs 1 . As illustrated in FIGS. 1 and 2 , each of the HDDs 1 includes a disk 4 that is a storage medium used for storing data. A system area 7 stores address translation information used for performing translation between a physical address that indicates a physical position on the disk 4 and a logical address that logically indicates the physical address. The address translation information read out from the system area 7 is written in a memory. The HDD 1 includes a write control section. When the HDD 1 receives a write instruction from the storage control device, the write control section translates a logical address, included in the write instruction, into a physical address by referring to the address translation information written in the memory and writes the logical address and data, both included in the write instruction, in a position indicated by the physical address. In addition, the HDD 1 includes a read control section. When the HDD 1 receives a read instruction from the storage control device, the read control section translates a logical address, included in the read instruction, into a physical address by referring to the address translation information written in the memory and reads data from a position indicated by the physical address.
[0031] The controller module 15 includes a central processing unit (CPU) 16 that performs arithmetic processing at the time an instruction is received, a read only memory (ROM) 17 that stores a program or the like, a random access memory (RAM) 18 that functions as a temporary storage area and deploys data such as a control table or the like, and an HDD interface 19 connected to the HDD 14 .
[0032] FIG. 3 illustrates the firmware configuration diagram of the RAID device. The RAID device 12 that is the storage control device includes a channel control section 20 that receives an instruction from the host 11 , a read/write control section 21 that controls a read/write operation for the HDD 1 , a cache control section 22 that controls a cache memory, and a device control section 23 that controls the HDD interface 19 . The read/write control section 21 includes a write instruction section 24 that controls a write operation for data and a read instruction section 25 that controls a read operation for data. The write instruction section 24 includes an LBA-value addition control section 26 that adds an LBA value, which is a logical address value, to user data. The read instruction section 25 includes address translation information correction section 27 that compares a read LBA value with an LBA value added to user data to be written and a user-data/LBA-value separation section 28 that separates an LBA value added to read user data from the user data.
[0033] When the read instruction section 25 receives a write instruction from the host, the read instruction section 25 sends a read instruction, which includes a logical address included in the write instruction from the host, to a storage device. On the basis of a read instruction from the data read instruction section, in the case in which data read from a corresponding position by the storage device includes a logical address, when the logical address included in the write instruction received from the host is different from the logical address included in the read data, the address translation information correction section reads the address translation information from the system area and writes the read address translation information in the memory.
[0034] In addition, when the data read instruction section 25 receives a read instruction from the host, the data read instruction section 25 sends a read instruction, which includes a logical address included in the read instruction from the host, to the storage device. On the basis of a read instruction from the data read instruction section, in the case in which data read from a corresponding position by the storage device includes a logical address, when the logical address included in the read instruction received from the host is different from the logical address included in the read data, the address translation information correction section reads the address translation information from the system area and writes the read address translation information in the memory.
[0035] Here, a RAID device will be described. The RAID device has seven levels ranging from RAID 0 to RAID 6 and balances reliability with speed by combining individual RAID levels. The RAID 1 writes the same content into a plurality of hard disks simultaneously. This operation is called mirroring. The RAID 1 is the simplest RAID and has high fault tolerance. In addition, in the RAID 1 , controller trouble, which is the greatest weakness of the RAID, is easily dealt with. At least two drives are necessary for the RAID 1 . When one drive is out of order, the other drive is unlikely to be out of order simultaneously. Therefore, the system can continue to work.
[0036] The RAID 5 prevents bottlenecks occurring in the RAID 3 and the RAID 4 by dispersing and storing data into a plurality of hard disks along with error-correcting code data. At least three drives are necessary for the RAID 5 . The RAID 5 has better usage efficiency than the RAID 1 and the RAID 1 + 0 . In addition, since the RAID 5 disperses and stores data into a plurality of disks in the same way as the RAID 0 , the RAID 5 has good readout performance. On the other hand, since the RAID 5 recreates parity at the time of a write operation, it is necessary for the RAID 5 to perform a read operation from a disk and a parity operation.
[0037] Next, translation between a logical address and a physical address, which is performed at the time a data read/write operation is performed in the storage control device, will be described. The translation information widely varies owing to the different types of storage devices such as HDDs or the like.
[0038] The following example according to the embodiment will be described. Since, as mentioned above, the translation information varies owing to the individual HDDs, the translation information is individually stored in the system area 7 that is a specific medium area in the HDD. The read/write control section associates, using the translation information, a physical address with a logical address and controls a read/write operation. A Table 1 illustrates the translation information from LBA to CHS, which is stored in the system area.
[0000]
TABLE 1
maximum sector value
9
maximum head value
3
maximum cylinder value
99
defect 1
C: 0, H: 0, and S: 4
defect 2
C: −1, H: −1, and S: −1
defect 3
C: −1, H: −1, and S: −1
[0039] In Table 1, the individual maximum numbers of sectors, heads, and cylinders and the physical positions of defect parts are illustrated.
[0040] In the translation information from a logical address to a physical address, it is supposed that there are 10 sectors from 0 to 9, a maximum sector value, 4 heads from 0 to 3, a maximum head value, and 100 cylinders from 0 to 99, a maximum cylinder value. Therefore, it is supposed that, because there are 10 sectors, 4 heads, and 100 cylinders, the HDD has 4000 blocks as a physical storage area. In addition, it is supposed that up to 3 medium defects are allowed, and an area in which three defect areas (defects 1 to 3) are stored is reserved. In addition, “C: 0, H: 0, and S: 4” is stored in the defect 1 illustrated in Table 1 and indicates that a portion corresponding to a physical position, that is, a cylinder that is “0”, a head that is “0”, and a sector that is “4”, is a medium defect. Since a negative value “−1” that does not physically exist in “C, H, and S” is stored in the defects 2 and 3, it is indicated that the defects 2 and 3 are not used. In Table 1, it is supposed that the number of medium defects is one and final physical positions are backups (backups 1 and 2) and not used. Namely, as a matter of logic, by constantly setting effective capacity to 3997 blocks, LBA 0 to LBA 3996, disk mediums including physical defects ranging from 0 to 3 are regarded, for a RAID device, as an HDD that includes a disk medium having a capacity of 3997 blocks in the same specification. An example of the relationship of the translation between logical addresses and physical addresses is illustrated in FIG. 4 .
[0041] FIG. 4 is a translation-information relationship diagram illustrating translation between logical addresses and physical addresses. As a defect that has existed already, the defect 1 is recorded to correspond to “C: 0, H: 0, and S: 4”. As mentioned above, FIG. 4 illustrates a correspondence relationship between LBAs, which are logical address values, and C indicating cylinders, H indicating heads, and S indicating sectors.
[0042] Here, an abnormality due to a soft error in the memory, which is resolved according to the embodiment of the present invention, will be described. When logical address/physical address translation is as illustrated in FIG. 4 , it is supposed that one bit of data on the memory is inverted owing to the soft error mentioned above. For example, FIG. 5 illustrates a correspondence relationship between logical addresses and physical addresses due to logical translation. A defect position corresponds to “C: 0, H: 0, and S: 4” indicated in the top line in a normal state. Owing to the soft error, “S: 4” (“0100” in 4-bit expression) in the “C: 0, H: 0, and S: 4” turns into “S: 0” (“0000” in 4-bit expression). As illustrated in the bottom line in an abnormal state, physical positions indicated by LBAs 0 to 3 turn out to be changed. Therefore, in the case in which the LBA 0 is read, while, in the normal state, user data (U 0 ) stored in the physical position “C: 0, H: 0, and S: 0” is supposed to be read, user data (U 1 ) stored in the physical position “C: 0, H: 0, and S: 1” turns out to be read in the abnormal state.
[0043] In comparison with the embodiment, a comparative example will be described. FIG. 6 illustrates state transition from a normal state to an abnormal state in the case in which LBA values are added. The addition of LBA values allows abnormality detection. Namely, by comparing an LBA value added to user data (Ux) with an LBA value prior to translation, an abnormality is detected in LBAs 0 to 3 at the time a read operation is performed.
[0044] Furthermore, as illustrated in FIG. 7 , in the case in which a write operation is performed in the abnormal state, data is written in a position that is different from a normal position. However, since, in the case in which a read operation is performed in the continued abnormal state, data is also read from the position that is different from the normal position in the same way, there is no discrepancy.
[0045] However, simply by adding LBA values, it is difficult to prevent a problem from occurring in the state in which a write operation is performed in the abnormal state, as illustrated in FIG. 8 . When a rewrite processing operation for address translation information from the system area to the memory is performed owing to power reactivation for the HDD or the like, the state of the translation information changes to the normal state. In this case, since, in the LBAs 1 to 3, LBAs 1 to 3 prior to translation do not match LBAs 1 to 3 added to the user data, an abnormality can be detected. However, since, in the LBA 0, that is, in the position corresponding to “C: 0, H: 0, and S: 0”, an LBA prior to translation is “0” and an LBA added to the user data is also “0”, thereby both matching each other, an abnormality is not detected.
[0046] In addition, “C: 0, H: 0, and S: 4” corresponds to a defect position on the medium. The defect is arbitrarily defined as a defect at which a data write failure occurs every 100 times or every 1000 times or the like. While a data write failure does not occur every time, a write operation is expected to be performed safely in the defect portion at about 80 percent probability.
[0047] However, user data corresponding to the position “C: 0, H: 0, and S: 0” is old and different from normal data. Therefore, in the embodiment, in addition to the addition of an LBA value, an LBA value added to user data to be written at the time a write operation is performed is compared with an LBA value added to user data stored at a write position on the medium. In addition, it is determined whether or not a logical address value that is logical address additional data read out is different from a logical address value indicating the object of an access instructed by the host. Accordingly, position miscalculation at the time the state changes from the abnormal state to the normal state can be detected.
[0048] FIG. 9 illustrates the flowchart of a write processing operation performed in the storage control device in the embodiment. When the RAID device receives an instruction from the host and performs a write processing operation (S 100 ), the channel control section in the RAID device receives a write instruction for user data from the host (S 101 ). Next, the LBA-value addition control section adds an LBA value to the user data received from the host (S 102 ). The LBA value indicates a position on the storage medium, in which the user data, an object of a write operation, is to be written (write LBA value). The read control section determines whether or not user data has been written in the write position (S 103 ).
[0049] When, as a result of the data presence/absence determination, it is determined that data has been written (S 103 Yes), the read control section reads the LBA value written in the write position (S 104 ). The LBA value is an LBA value added to user data already written. In addition, the address translation information correction section compares the read LBA value with the LBA value added to the user data to be written (S 105 ).
[0050] When, as a result of the comparison of the LBA values, it is determined that the LBA values are the same (S 105 Yes), the device control section rereads logical address/physical address translation information, stored in a RAM in the HDD, from the system area on the disk medium, and sets a translation-information reread flag to “0” (S 106 ). The translation-information reread flag is stored in a RAM in the controller module or the RAM in the HDD. The translation information may be stored in the RAM in the controller module rather than the RAM in the HDD. In addition, the write control section causes the user data and the added LBA value to be written (S 107 ), and after that the write processing operation is terminated (S 108 ).
[0051] In addition, when, as a result of the data presence/absence determination, it is determined that data has not been written (S 103 No), there is no LBA value to be compared with an added write LBA value. Therefore, the write processing operation is performed without change (S 107 ), and after that the write processing operation is terminated (S 108 ). In the case in which, even if there is no user data, an LBA value has been stored in a storage area on the disk medium, it is determined that data has been written, at the time of the data presence/absence determination.
[0052] On the other hand, when, as a result of the comparison of the LBA values, it is determined that the LBA values are not the same (S 105 No), it is determined whether or not the translation-information reread flag is “1” (S 109 ). When the translation-information reread flag is not “1” (S 109 No), the translation information stored in the system area on the disk medium is read into the RAM (S 110 ). In addition, the translation-information reread flag is set to “1”, and the data presence/absence determination at the write position is performed (S 103 ).
[0053] When the translation-information reread flag is “1” (S 109 Yes), error termination is performed without change (S 112 ). The case that the translation-information reread flag is “1” means that, while LBA values are compared after a translation information reread operation is performed, the LBA values are not the same. Namely, since there is a possibility that a successive abnormality exists, error is reported to the host.
[0054] According to the storage control device in the embodiment, an abnormality can be detected by confirming, prior to a write operation, whether or not there is an abnormality in a position in which data is to be written.
[0055] Next, a second embodiment of the storage control device will be described.
[0056] The comparison determination between the LBA values is performed at a time different from that in the first embodiment. At a predetermined time, the storage control device confirms an LBA value written in a corresponding physical position on the medium. The predetermined time may be a time when there is no access instruction from the host to the HDD or a time when power is activated. A periodic patrol processing operation, performed at a time other than a time when a write operation or a read operation is instructed, causes a burden, imposed on write and read operations, to be reduced.
[0057] When an LBA value added to user data is confirmed and the temporal abnormality of address translation due to a soft error in the memory is detected, the information of translation from LBA to CHS is read from the system area and stored in the RAM. Accordingly, using normal translation information, the storage system can perform address translation.
[0058] FIG. 10 is a flowchart illustrating the patrol processing operation. The patrol processing operation (S 113 ) is periodically performed. The read/write control section determines an LBA value to be subjected to the patrol processing operation (S 114 ). In addition, the channel control section determines whether or not an access instruction is sent from the host to the HDD (S 115 ). When no access instruction is sent from the host (S 115 No), the read/write control section uses, through the device control section, the translation information table stored in the RAM in the HDD, and identifies a position on the medium by translating an LBA value used for the patrol processing operation into CHS information indicating a physical position on the medium (S 116 ). In addition, an LBA value (an LBA value to be read) stored in the position is read (S 117 ).
[0059] Here, the address translation information correction section determines whether or not the LBA value set for the patrol processing operation and the LBA value to be read are the same (S 118 ). When the LBA value set for the patrol processing operation is different from the LBA value to be read (S 118 No), it is confirmed whether or not the translation-information reread flag has been set to “1” (S 119 ). When the translation-information reread flag is not “1” (S 119 No), the translation information stored in the system area SA is read into the RAM on the HDD (S 120 ). In addition, the translation-information reread flag is set to “1”, and the process returns to the operation in which it is determined whether or not there is an access instruction from the host (S 114 ), again. In addition, when the translation-information reread flag is “1”, an error is reported to the host, and after that error termination is performed (S 122 ).
[0060] On the other hand, when the LBA value set for the patrol processing operation and the LBA value to be read are the same (S 118 Yes), it is determined that there is no abnormality, and, by adding one to the LBA value for the next patrol processing operation, an LBA value indicating a next position is set up (S 123 ). After setting up the LBA value, the translation-information reread flag is set to “0” (S 124 ) and the process is terminated (S 125 ) to wait till the next patrol processing operation is performed.
[0061] When an access instruction is output from the host at the time patrol processing operation is started (S 115 Yes), the process is terminated without performing the patrol processing operation (S 125 ). After a predetermined time elapses, abnormality detection is performed by patrolling an LBA value again.
[0062] Next, the patrol processing operation after a defect position is identified will be described. A value that is not used as an actual address, such as “−1” or the like, is written as an LBA value added at the time a defect registration operation is performed. In addition, an LBA value written in a position in which there is supposed be a defect is read at the time power is activated or there is no access, and it is confirmed whether or not the LBA value is “−1”. When the LBA value read from the defect position is a value, such as “1” or the like, that indicates a position actually existing on the medium, it is determined that, owing to position miscalculation caused by a temporal abnormality such as a soft error or the like, the LBA value has been written in an erroneous position. While a defect portion is arbitrarily set by a user or a manufacturer, a write operation can be performed at about 80 percent probability in a storage area that is registered as a defect portion. Therefore, write and read operations for the LBA value are performed.
[0063] FIG. 11 is a flowchart illustrating the patrol processing operation (S 126 ) in which a defect position is identified. In the storage control device according to the embodiment, a value, such as “−1”, that does not exist on the medium is written in advance in a block that is on the medium and defined as a defect position. The case in which an actual LBA value exists in LBA values added to the defect portions indicates that a translation abnormality occurs at the time a write operation is performed and hence the LBA value has been written in a position that is not a proper position in which the LBA value is to be written.
[0064] The read control section causes the defect position information to be read from the translation information deployed in the RAM in the HDD (S 127 ). On the basis of the defect position information read from the translation information, an LBA value on the medium is read and stored in the RAM (S 128 ). It is determined whether or not the LBA value (defect position LBA) is “−1” (S 129 ). When the defect position LBA is “−1” (S 129 No), it is determined whether or not the translation-information reread flag is “1” (S 130 ). When the translation-information reread flag is not “1” (S 130 No), the translation information stored in the system area is reread and stored in the RAM (S 131 ). In addition, the translation-information reread flag is set to “1” (S 132 ), the operation in which the defect position information is read from the translation information deployed in the RAM in the HDD is performed again (S 127 ).
[0065] In addition, when the translation-information reread flag is “1” (S 130 Yes), an error is reported to the host, and after that the process is terminated (S 133 ).
[0066] On the other hand, the defect position LBA value is “−1” (S 129 Yes), one is added to the defect position LBA (S 134 ), and after that the process is terminated (S 135 ). After a predetermined time elapses after the process is terminated, the patrol processing operation is repeated till all LBA values are determined.
[0067] In addition, the LBA values may be added to a servo location information portion rather than a user data portion. Since servo information is certainly read both in a write operation and a read operation, the comparison of the LBA values can be performed in real time by adding the LBA values to the servo location information portion. Therefore, high efficiency can be achieved. In addition, when a defect registration operation is performed, an LBA value added to the servo information is updated. Since, except at times the defect registration operation and an initialization operation are performed, the translation information from the LBA to the CHS is not changed, the translation information is updated only at times the defect registration operation and the initialization operation are performed. Therefore, the method according to the embodiment can reduce processing time in comparison with a method in which an LBA value is added to user data whenever a write operation is performed.
[0068] In another embodiment, translation information that is periodically stored in a system area at a time there is no access from a host may be compared with translation information written in a memory. The translation information stored in the system area is compared with the translation information written in the memory, and hence a mismatch between data in the two pieces of translation information is determined. When the mismatch is confirmed in the comparison, the translation information written in the memory is updated using the translation information stored in the system area. According to the storage control device in the embodiment, since the translation information itself is compared, burdens are not placed on write and read processing operations.
[0069] As described above, the storage control device disclosed in the embodiments can prevent a successive abnormality regarding translation between a logical address and a physical address and miscalculation of data position due to a temporal abnormality such as a soft error are detected. The storage control device disclosed in the embodiments can prevent a data abnormality caused by the mistranslation between a logical address and a physical address, and then can ensure reliability of data storing of the storage system.
[0070] All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention. | A storage control device for controlling the storage device including a medium for storing data, logical address information, and address translation information and a memory for storing the address translation information read from the medium includes a first receiver for receiving a write request including logical address information, a first sending module for sending a read request including the logical address information of the write request to the storage device, a second receiver for receiving data and logical address information stored in the medium in accordance with the read request from the storage device, and a second sending module for sending an instruction to cause the storage device to write the address translation information stored in the medium into the memory when the logical address information received by the second receiver is different from logical address information included in the write request. | 6 |
This application is a continuation of Ser. No. 551,269, filed Nov. 14, 1983, now abandoned.
BACKGROUND OF THE INVENTION
(a) Field of the invention
The present invention relates to an automatic accompaniment apparatus for electronic musical instruments, which is capable of automatically producing accompaniment tones such as bass tones and arpeggio tones.
(b) Description of the prior art
An automatic accompaniment, in general, means such a performance that accompaniment tones are prepared by circuitries in the instrument upon respective depressions of the keys, and that, thereafter, they are sounded at such timings as required in accordance with the predetermined rhythm to automatically produce, for example, bass tones and arpeggio tones.
As a typical conventional automatic bass accompaniment apparatus, there has been proposed one which is arranged so that, at each time of depression of a chord, a root note data representing the root note of the chord and interval data read out from the memory are, for example, respectively added together to form respective bass key data, and that bass tones are respectively and sequentially produced in accordance with these bass key data. Also, as a typical conventional automatic arpeggio accompaniment apparatus, there has been proposed one which is arranged so that at each time of depression of a chord, depressed key data of the depressed chord (for example C, E, G) are written in the memory, and that the depressed key data requiring sounding are searched successively from the low pitch note side to the high pitch note side, using, as trigger signals, the pulses of a certain period (for example, a time length of a 16th note), and that the depressed key data thus obtained from the search are given an appropriate processing such as an octave processing, to thereby produce arpeggio tones.
The above-mentioned automatic bass accompaniment apparatus and arpeggio accompaniment apparatus are effective for use in a circuit system wherein both the bass tone generation and the arpeggio tone generation are performed in parallel. However, in order to use such apparatuses in a system wherein the bass tone generation and the arpeggio tone generation are processed time-divisionally (i.e. in series), especially in a system wherein they are subjected to time division processing by using a micro-computer, the computation processing requires an undesirably lengthy time, so that there is a drawback in that it is difficult to generate both bass tones and arpeggio tones in synchronism with the selected rhythm. More particularly, in an ordinary electronic musical instrument, chord tones, bass tones, arpeggio tones and so forth should be generated in synchronism with rhythm tones. If, however, an undesirably lengthy time is required for the computation processing intended for the generation of the respective tones, the result is that the bass tones, arpeggio tones and other accompaniment tones undesirably will become generated with delays for the given rhythm timings.
In order to solve these problems mentioned above, there may be used a computer which is capable of performing high-speed computation. However, the incorporation of such a computer in an electronic musical instrument is non-realistic in view of, for example, cost and space.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a new automatic accompaniment apparatus which is able to generate such tones as bass and arpeggio in sufficiently satisfactory synchronism with a given rhythm even when there is employed a time divisional processing by a low-speed small-size computer such as a micro-computer.
The automatic accompaniment apparatus of an electronic musical instrument according to the present invention intended to attain the above-mentioned object is arranged so that, at the time of the depression of accompaniment keys, there are formed and secured (i.e. prepared) key data for the accompaniment tones which have the possibility of being sounded, and at respective accompaniment tone generating timings which are synchronized with the rhythm, desired accompaniment tones such as bass tones or arpeggio tones are generated only by selecting the already prepared key data, to thereby materialize the proper timings of sounding.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1B and 1C are, in combination, a block diagram of an electronic musical instrument representing an embodiment of the present invention.
FIG. 2 is an illustration showing the arrangement of data in a memory table.
FIG. 3 is an illustration showing the arrangement of data in a pattern memory.
FIG. 4 is an illustration of construction of an accompaniment tone buffer.
FIG. 5 is an illustration of construction of a sounding bass/arpeggio data memory.
FIG. 6 is an illustration showing the arrangement of registers in the working area.
FIG. 7 is a flow chart of main routine.
FIGS. 8A and 8B are, in combination, a flow chart of a bass tone setting sub-routine.
FIG. 9 is a flow chart of semi-tone down sub-routine.
FIG. 10 is a flow chart of semi-tone up sub-routine.
FIG. 11 is a flow chart of whole-tone down sub-routine.
FIGS. 12A and 12B are, in combination, a flow chart of arpeggio tone setting sub-routine.
FIG. 13 is a flow chart of interruption routine.
FIGS. 14A and 14B are, in combination, a flow chart of bass tone output sub-routine.
FIGS. 15A and 15B are, in combination, a flow chart of arpeggio conversion sub-routine.
FIG. 16 is a flow chart of arpeggio tone storage sub-routine.
FIG. 17 is a flow chart of arpeggio tone output sub-routine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A, 1B and 1C show, in combination, an electronic musical instrument of an embodiment of the present invention. This electronic musical instrument is arranged so that, by the aid of a micro-computer, the generation of, for example, melody tones, chord tones, bass tones, arpeggio tones and rhythm tones is controlled.
A keyboard unit 10 includes an upper keyboard UK, a lower keyboard LK and a pedal keyboard PK. A panel switch (SW) circuit 12 contains a number of manipulation buttons or knobs arranged on the face of a panel, including UK/LK tone color selection switches, a rhythm start/stop switch, rhythm selection switches, a tempo control, walking bass selection switches, arpeggio selection switches, and mode selection switches.
A keyboard/panel interface 14 is coupled, via a busbar 16, to a central processing unit CPU 18. This CPU 18 is arranged to make, via the interface 14, a scanning of the keys of the respective keyboards of the keyboard unit 10 as well as the various switches of the panel switch circuit 12, to thereby detect the key state information and the switch state information.
The musical tone generation controlling operation by the CPU 18 is controlled by a program stored in a program memory 20 which is comprised of a ROM (Read Only Memory), the details of which will be described later.
A memory table which is generally indicated at 22 and which is comprised of a ROM contains a chord detection table 22a, a bass tone table 22b and a tone duration table 22c. Of these tables, the chord detection table 22a stores chord name data corresponding to the lower key (LK) depression state separately for the fingered chord (FC) mode and for the single finger (SF) mode. Here, each of the chord name data is comprised of combination of a tonic data corresponding to the root note of a chord and chord type data corresponding to such a chord type as major or minor, etc. In case of FC mode, the root note and the chord type are determined in correspondence to the actual depression of chord keys on the lower keyboard LK. In case of SF mode, on the other hand, the root note is determined in correspondence to the highest note or the lowest note key among the depressed keys on the lower keyboard LK, and the chord type is determined in accordance with the state of those keys other than the root note key (e.g. the kind of key such as a sharp key or a natural key or the number of the depressed keys). It should be noted here that the designation of the chord type in case of SF mode may be arranged so that it is performed by the pedal keyboard PK or by separate chord type designation switches.
As shown in FIG. 2, the bass tone table 22b possesses twelve (12) memory sections corresponding to the respective ones of the tonics C, C♯, D, . . . , B. Each memory section stores key code data for sixteen (16) diatonic scale notes which have the possibility of being sounded, such as C 2 , D 2 , E 2 , . . . , D 4 in case of tonic C; and C 2 ♯, D 2 ♯, F 2 , F 2 ♯, G 2 ♯, A 2 ♯, C 3 ♯, . . . in case of tonic C♯.
The tone duration table 22c stores time length data indicative of the duration of various tones, and this table is arranged so that the time length data is read out by using, as the relative addresses, the values indicated by the tone duration data contained in the pattern data which will be described later.
A pattern memory 24 which is comprised of a ROM contains a bass pattern memory 24a, a chord pattern memory 24b, a rhythm pattern memory 24c and an arpeggio pattern memory 24d. The bass pattern memory 24a and the arpeggio pattern memory 24d store, as shown in FIG. 3, pattern data for respective kinds of rhythms such as march, swing, . . . , waltz.
More specifically, the bass pattern data which is shown of its one example with respect to march rhythm is such that the data for one tone is comprised of two-byte data, of which the first byte contains a two-bit tone volume data ACC, a one-bit mute data M, a non-use ("0") one-bit, and a four-bit sounding timing data TMG, and the second byte includes a four-bit tone pitch data, and a four-bit tone duration data.
Here, the tone volume data ACC is intended to add an accent to a bass tone. The mute data M is intended to control the tone color or the sustain time of a bass tone to generate a mute tone which gives a somewhat dull impression. The sounding timing data TMG is intended to indicate the sounding timing of any one of 0˜11 within one beat (corresponding to a single quarter note), and the sounding timing values 0˜11 correspond to the count values 0˜11 of an intra-beat timing counter which will be described later. The tone pitch data is intended to enable the reading-out of a key data corresponding to the specific bass tone which is to be sounded, by designating any one of the addresses of 0˜15 contained in the bass tone buffer which will be described later. The tone duration data is intended to indicate, by a digital value corresponding to the note type, the "on" time from the rise up to the start of sustain of a bass tone which is to be sounded (corresponding to the key-on time in case of pedal keyboard PK), and this digital value corresponds to an address of the tone duration table 22c. More particularly, the tone duration data per se only indicates to which note the "on" time of the bass tone corresponds. Therefore, in order to know the length of the "on" time of the bass tone (meaning the tone duration), it is necessary to read out the time length data of the tone duration table 22c based on the tone duration data.
In case, as shown in FIG. 3, there are a plurality of bass tones which are to be sounded within a single beat, two-byte data corresponding to the respective bass tones are arranged successively, and at the end thereof is arranged a beat-end flag data ("0D" in hexadecimal notation). And, it should be noted that such arrangement as mentioned above is made in similar fashion for any required number of beats, and in each case a return flag data ("0F" in hexadecimal notation) is arranged at the end thereof.
The arpeggio pattern data, as its one example, is shown with respect to "march", is such that the data for one tone is comprised of data of two bytes, the first byte of which contains a one-bit tone volume data ACC, a two-bit channel data CH, a one-bit mute data M and a four-bit sounding timing data TMG, and the second byte includes a four-bit tone pitch data and a four-bit tone duration data.
Here, the tone volume data ACC, the mute data M, the sounding timing data TMG, the tone pitch data and the tone duration data possess functions similar to those described above, respectively. The channel data CH is intended to designate either one of the four music tone forming channels. Also, the manner of disposing the two-byte data, the beat-end flag data ("0D" in hexadecimal notation) and the return flag data ("0F" in hexadecimal notation) is similar to that for the abovesaid bass pattern data.
The chord pattern memory 24b stores chord pattern data containing sounding timing data, sounding controlling data for tone volume, tone color and so forth, and tone duration data. The manner of disposing these data is similar to that for the above-mentioned bass pattern data. Also, the rhythm pattern data memory 24c stores rhythm pattern data containing sounding timing data, musical instrument type designating data, and sounding controlling data for tone volume, tone color and so forth, and the manner of disposing these data is similar to that for the above-mentioned bass pattern data.
An accompaniment tone buffer 26 which is comprised of a RAM (Random Access Memory) contains a chord buffer 26a, a bass tone buffer 26b and an arpeggio tone buffer 26c. As shown in FIG. 4, the chord buffer 26a is adapted to be able to store chord-tone key code data for four (4) tones, and the bass tone buffer 26b is adapted to be able to store bass-tone key code data for 16 tones, and the arpeggio tone buffer 26c is adapted to be able to store arpeggio-tone key code data for 16 tones.
A sounding base/arpeggio data memory 28 which is comprised of a RAM contains three memory sections BASRAM 0 ˜BASRAM 2 for bass and 16 memory sections ARPRAM 0 ˜ARPRAM 15 for arpeggios as shown in FIG. 5, and is utilized at the time of the base/arpeggio sounding processing (FIGS. 14A˜17) which will be described later. The BASRAM 0 is intended to store an off-timing data, and the BASRAM 1 is intended to store a key code data, and the BASRAM 2 is intended to store a sounding controlling data (tone volume data ACC and mute data M).
Also, ARPRAM 0 ˜ARPRAM 3 , ARPRAM 4 ˜ARPRAM 7 , ARPRAM 8 ˜ARPRAM 11 and ARPRAM 12 ˜ARPRAM 15 are provided to correspond to the first, second, third and fourth music tone forming channels, respectively. The ARPRAM 0 , ARPRAM 1 , ARPRAM 2 and ARPRAM 3 are adapted, respectively, to store an on-key code data, an off-timing data, and off-key code data and a sounding controlling data (tone volume data ACC, mute data M and channel data CH), for the first music tone forming channel. Such share of memory applies also similarly to the ARPRAM 4 ˜ARPRAM 7 for the second music tone forming channel, and to the ARPRAM 8 ˜ARPRAM 11 for the third music tone forming channel, and to the ARPRAM 12 ˜ARPRAM 15 for the fourth music tone forming channel, respectively.
The working area 30 consisting of a RAM contains various kinds of flags, registers and so forth. The arrangement of those registers related to the working of the present invention is as shown in FIG. 6. More specifically, TONIC represents a register for writing-in a tonic data corresponding to the root note of a detected chord. TYPE represents a register for writing-in a chord type data corresponding to a detected chord type. RHYROM, CHDROM, BASROM and ARPROM are registers for setting the pattern leading addresses of the rhythm pattern memory 24c, the chord pattern memory 24b, the bass pattern memory 24a and the arpeggio pattern memory 24d, respectively, in accordance with a selected type of rhythm.
RHYRUN represents a rhythm run flag which is set at the time of a rhythm start, and reset at the time of a rhythm stop. TMPCNT represents an intra-beat timing counter which counts the timing (interruption timing) number within a beat in such a way that the count value steps from 0 to 11 within a single beat and repeats the same for every new beat. TIMING represents an intrameasure timing counter which counts the timing (interruption) number within a beat in such a way that the count value steps from 0 to 35 (in case of three beats or triple meter) or from 0 to 47 (in case of four beats or quadruple meter) within a single measure and repeats the same for every new measure. TMPMAX represents a register in which is set the maximum timing value of 36 (in case of three beats) or of 48 (in case of four beats) for the counter TIMING. It should be noted that the determination of three beats or four beats is made in accordance with the type of the rhythm selected.
RHHEND, CDHEND, BAHEND and ARHEND represent beat-end flags for rhythm, chord, bass and arpeggio, respectively, and they are set at the time of detection of a corresponding beat-end flag data. Also, RHPNT, CDPNT, BAPNT and ARPNT represent address pointers which are utilized when data are read out from the rhythm pattern memory 24c, the chord pattern memory 24b, the bass pattern memory 24a and the arpeggio pattern memory 24d, respectively, and they indicate relative addresses from the leading edge of the respective patterns.
ARPCNT represents a register in which is set the number of arpeggio tones which are to be sounded. In this instant embodiment, there are provided four music tone forming channels for arpeggio, and therefore the number of the arpeggio tones for being sounded is limited to four or less.
OCTDW represents a register in which is set the octave number which requires to be downed in the arpeggio tone setting processing (FIGS. 12A and 12B). PKWON represents a state flag of the walking base selection switch. ARPON represents a state flag of the arpeggio selection switch. ARCH represents a register in which is written a data for designating the music tone forming channel in the processing of conversion into arpeggio (FIGS. 15A and 15B) (in case of the first channel, "00" in hexadecimal notation; in case of the second channels, hexadecimal "04"; in case of the third channels, hexadecimal "08"; and in case of the fourth channels, hexadecimal "0C"). LKCNT represents a register in which is set the number of the depressed keys on the lower keyboard LK. LKHLBF represents a buffer register which is capable of writing-in key code data for ten (10) tones and corresponding to the depressed keys on LK by arraying in successive order from the data of higher pitch keys. It should be understood here that the working area 30 contains various other registers than those mentioned above.
Here, the manner of determining key codes will be described. A key code KC is indicated by the sum of octave code OC and note code NC. The octave code OC and the note code NC are as shown in Table 1 and Table 2, respectively.
TABLE 1______________________________________Octave Tone range Code (hexadecimal)______________________________________OC.sub.1 C.sub.2 ˜B.sub.1 00OC.sub.2 C.sub.3 ˜B.sub.3 10OC.sub.3 C.sub.4 ˜B.sub.4 20OC.sub.4 C.sub.5 ˜B.sub.5 30OC.sub.5 C.sub.6 ˜B.sub.6 40OC.sub.6 C.sub.7 50______________________________________
TABLE 2______________________________________Note name Code (hexadecimal)______________________________________C 1C.sup.# 2D 3D.sup.# 4E 5F 6F.sup.# 7G 8G.sup.# 9A AA.sup.# BB C______________________________________
According to Table 1 and Table 2 mentioned above, for example C 2 , C 3 , C 4 , B 2 and B 4 are indicated by hexadecimal "01", "11", "21", "0C", "1C" and "2C", respectively. It should be noted here that hexadecimal "D", "E" and "F" following hexadecimal "C" and the hexadecimal "0" are not used as note codes, but that hexadecimal "0D" and "0F" are used in beat-end flag data and also in return flag data, respectively, as stated above.
A UK interface 32 supplies, to a UK music tone forming circuit 34, a UK tone color data based on a panel switch manipulation and UK key data based on UK manipulation. Said circuit 34 forms UK music tone signals in accordance with the data thus supplied. These UK music tone signals are supplied to a loudspeaker 38 via an output amplifier 36, to be converted to sounds.
An LK interface 40 supplies, to an LK music tone forming circuit 42, an LK tone color data based on the panel switch manipulation and LK key data based on the LK manipulation, and this circuit 42 forms LK music tone signals in accordance with the data supplied thereto. These LK music tone signals are supplied to the loudspeaker 38 via the output amplifier 36, to be converted to sounds. The UK key data output processing via the UK interface 32 is performed according to the main routine which will be described later by referring to FIG. 7. However, the LK key data output processing via the LK interface 40 from the chord buffer 26a is performed according to the interruption routine which will be described later by referring to FIG. 13.
A bass interface 44 contains an on-key code (ONKC) register 46, an off-key code (OFFKC) register 48, an assignment controlling circuit 50, a key-code (KC)/key-on (KON) register 52 and a sounding controlling data register 54, and is arranged so that it will assign key data alternately to two music tone forming channels so as to be able to sustain the sounding of the bass tone proceeding to a certain bass tone which is being sounded. The key data and the sounding controlling data supplied from the bass interface 44 are supplied to a bass tone forming circuit 56, and this latter circuit 56 forms bass tone signals based on the data supplied one after another thereto. These bass tone signals are supplied to the loudspeaker 38 via the output amplifier 36, to be converted to sounds.
An arpeggio interface 58 contains an on-key code (ONKC) register 60, an off-key code (OFFKC) register 62, an assignment controlling circuit 64, a key code (KC)/key-on (KON) register 66 and a sounding controlling data register 68, and is arranged so that, in accordance with the channel data CH contained in the sounding controlling data, it assigns a key data to a pertinent one of the four music tone forming channels. The key data and the sounding controlling data coming from the arpeggio interface 58 are supplied to an arpeggio tone forming circuit 70, and this circuit 70 forms arpeggio tone signals based on the data supplied thereto. These arpeggio tone signals are supplied one after another to the loudspeaker 38 via the output amplifier 36, to be converted to sounds.
A rhythm interface 72 supplies, to a rhythm tone forming circuit 74, data for designating the types of the musical instruments which are to sound and sounding controlling data, and said circuit 74 forms rhythm tone signals in accordance with the data supplied thereto. These rhythm tone signals are supplied to the loudspeaker 38 via the output amplifier 36, to be converted to sounds.
The bass data output processing via the bass interface 44 from the bass tone buffer 26b, the arpeggio data output processing via the arpeggio interface 58 from the arpeggio tone buffer 26c, and the rhythm data output processing via the rhythm interface 72 are all performed in accordance with the interruption routine which will be described later with respect to FIG. 13.
A tempo timer 76 is intended to generate twelve (12) timing pulses within a single beat in accordance with a tempo which has been set by the tempo control knob, and to apply an interruption to the main routine 12-times within a single beat in accordance with each pulse.
Main Routine
Next, the processing by main routine will be described by referring to FIG. 7. Upon turning-on the power supply switch not shown, the processing by main routine starts, and the respective keyboards, the respective panel switches and so forth are scanned to detect key state informations and switch state informations. And, whether or not there is any change in the state of keys, panel switches and so forth is judged. If the result of the judgment is "no" N, the scanning and the detecting operations are repeated. Also, in case the result of judgment whether there is a change in the state is "yes" Y, the state informations concerning the keyboards, panel switches and so on are stored once in the corresponding data registers in the working area 30, respectively.
Next, whether there is a change in the state of keys of the lower keyboard LK is judged. Usually, there are performed manipulation of various manipulating buttons and knobs on the panel prior to starting the depression of keys on the lower keyboard LK. In such case, the result of judgment as to whether there is a change in LK will be "no" N, and a processing based on the manipulation of the manipulating buttons and knobs on the panel is performed. That is, based on the manipulation of the UK tone color selection switch and the LK tone color selection switch, a UK tone color data is delivered from the working area 30 to the UK music tone forming circuit 34 via the UK interface 32, and also an LK tone color data is delivered to the LK music tone forming circuit 42 from the working area 30 via the LK interface 40. Also, based on the manipulation of the rhythm selection switch, leading-addresses of respective patterns are set in respective registers RHYROM, CHDROM, BASROM and ARPROM in accordance with the type of the rhythm selected. And, in the register TMPMAX is set a maximum timing value which is either 36 or 48 in accordance with the selected rhythm which may be either three beats (triple meter) or four beats (quadruple meter).
Further, based on a rhythm start by the manipulation of the rhythm start/stop switch, the rhythm run flag RHYRUN is set, and the counters TMPCNT and TIMING are cleared, and pointers RHPNT, CDPNT, BAPNT and ARPNT are cleared, and the tempo timer 76 is initialized, and the beat-end flags RHHEND, CDHEND, BAHEND and ARHEND are cleared. It should be noted here that, in case the rhythm start/stop switch is manipulated to the "stop" position, the rhythm run flag RHYRUN is cleared.
Further, based on the manipulation to turn-on the walking bass selection switch, the state flag PKWON is set. Also, based on the manipulation to turn-on the arpeggio selection switch, the state flag ARPON is set. In case either the walking bass selection switch or the arpeggio selection switch is turned off, either the state flag PKWON or ARPON is reset accordingly.
Now, when key depression on the lower keyboard LK is started, the judgment as to whether there is a change in LK becomes "yes" Y, and thus processing to set the number of the depressed keys of LK and to set the depressed key tones of LK takes place. That is, the number of keys depressed on LK is set on the register LKCNT, and concurrently those key code data corresponding to the depressed keys on LK are arrayed in successive order from the higher pitch side, and they are written in the buffer register LKHLBF.
Next, in accordance with the LK key depression state, and depending on whether the mode is FC mode or SF mode, the chord detection table 22a is referred to, and thus a chord is detected. The tonic data corresponding to the detected root note is written in the register TONIC, and concurrently the chord type data corresponding to the detected chord type is written in the register TYPE. Here, the data format in the register TONIC is arranged so that the higher four (4) bits in one byte which consists of eight (8) bits are not used, and the remaining lower four (4) bits represent the tonic note number of 1˜12. Also, the data in the register TYPE, likewise, are arranged so that the higher four (4) bits are not used and the remaining lower four (4) bits represent the chord type.
Next, processing will move onto the bass tone setting sub-routine, and a bass tone key code data for sixteen (16) tones which have the possibility of being sounded in connection with the detected chord are stored in the bass tone buffer 26b. The details of this processing will be described later with respect to FIGS. 8A and 8B.
Next, the processing will move onto the arpeggio tone setting sub-routine. An arpeggio-tone key code data for sixteen (16) tones which could be sounded in connection with the detected chord are stored in the arpeggio tone buffer 26c. The details of this processing will be described later in connection with FIGS. 12A and 12B.
Thereafter, a chord data is set in the chord buffer 26a. The chord data which is set here will be key code data corresponding to the LK depressed keys in case of FC mode, and it will be key code data of the chord constituent tones of the chord which is formed in accordance with the detected root note and chord type in case of SF mode.
When the above-stated processings are completed with respect to an instance wherein there is a change in the state of the keyboards, panel switches and so forth, the processing returns to that of the detection of the state of the keyboards, panel switches and so forth, and subsequently similar steps are repeated.
Bass Tone Setting Sub-routine
Next, description will be made of the bass tone setting sub-routine processing by referring to FIGS. 8A and 8B.
Firstly, a tonic data of the register TONIC is loaded in the register A in the CPU 18. And, by shifting the tonic data loaded in the register A in the CPU 18 left by four bits, it is multiplied to sixteen (16) times. As stated above, a tonic data is arranged so that its lower four (4) bits represent the tonic note number 1˜12 (corresponding to tonic C, C♯, D, . . . , B in the bass tone table 22b). Accordingly, by multiplying the tonic data of the register A sixteen (16) times, there is obtained a 16-timed (hexadecuple) tonic data indicative of a value which may be either 16, 32, 48, . . . , 192.
Next, the 16-timed tonic data is transmitted from the register A to the register X in the CPU 18. And, by writing-"00" in hexadecimal notation in the register Y in CPU 18, the digital value "0" is set therein. This is intended to enable the writing-in of the initial key code data in the bass tone buffer 26b.
Next, as shown in FIG. 2, let us here assume that the leading address value (fixed value) of the bass tone table 22b is BASTB, and that the value of the 16-timed tonic data which has been stored earlier in the register X is X, a mathematical operation (BASTB-16+X) is carried out to obtain the address value of the key code data which is to be read out initially from the table 22b, and the key code data at this address is read out from the table 22b and it is loaded on the register A. And, when, as shown in FIG. 4, the leading address value (fixed value) of the bass tone buffer 26b is assumed to be BASBF, this latter value is added with the value of the register Y, whereby the address which is to be written initially in bass tone buffer 26b is designated, and the initial key code data coming from the register A is stored therein. The result represents that, among the key code data for sixteen (16) tones belonging to a given tonic corresponding to the root note of the detected chord, the first key code data has been transmitted via the register A from the bass tone table 22b to the bass tone buffer 26b. Thereafter, the value of the register X and the value of the register Y are upped (increased) by "one" respectively to advance the read-out address and the write-in address by "one", respectively. And, whether the value of the register Y is equal to "16" is judged, and if the result is "no" N, such a transmission of the key code data as mentioned above is repeated. Such a transmission step inclusive of the first one is repeated sixteen (16) times, and the result is that all the key code data for sixteen (16) tones belonging to the given tonic have been transferred from the bass tone table 22b to the bass tone buffer 26b.
At such time, the value of the register Y becomes sixteen (16), and the judgment whether the value of the register Y is sixteen (16) becomes "yes" Y. Therefore, the processing will next move onto that of adjusting the data in the bass tone buffer 26b in accordance with the chord type. To begin with, the chord type data of the register TYPE is loaded on the register A, and whether the value of the register A is "01" in hexadecimal notation is checked, to judge whether the chord type is "seventh", and if "yes" Y, the 7th degree tone data ("06" in hexadecimal notation) for this chord is set in the register X. And, the processing will then move over to such a semi-tone down sub-routine as will be described later with respect to FIG. 9, and the tone pitch (code value) of the key code data corresponding to the 7th degree tone in the bass tone buffer 26b is downed (decreased) by a semi-tone, and with this the processing completes.
If the result of the judgment whether it is seventh (7th) is "no" N, a check whether the value of the register A is "04" in hexadecimal notation is made, whereby whether the chord type is minor "m" is judged. If the result of this judgment is "yes" Y, the third degree tone data ("02" in hexadecimal notation) of this chord is set in the register X. And, the processing moves over to the semi-tone down sub-routine, and the tone pitch of the key code data corresponding to the third degree tone in the bass tone buffer 26b is downed by a semi-tone, and with this the processing completes.
If the result of the judgment as to "minor" is "no" N, a check is made as to whether the value of the register A is "05" in hexadecimal notation to judge whether the chord type is minor seventh (m 7 ). If the result of this judgment is "yes" Y, the third degree data is set in the register X as in the abovesaid "minor" case, and a semi-tone down sub-routine is carried out. Next, as in the case of the "seventh" at the processing stated above, the seventh degree tone data is set in the register X, and the semi-tone down sub-routine is carried out, and with this, the processing completes.
In case the judgment for "minor seventh" is "no" N, whether the value of the register A is "06" in hexadecimal notation is checked, whereby whether the chord type is minor seventh with 5th degree flat (m 7 (5b)) is judged. If the result of this judgment is "yes" Y, the third degree tone data is set in the register X as in the case of "minor" described above, and the semi-tone down sub-routine is carried out. Next, by setting the 5th degree data ("04" in hexadecimal notation) in the register X and by carrying out the semi-tone down subroutine, the note pitch of the key code data corresponding to the 5th degree tone in the bass tone buffer 26b is downed by a semi-tone. Thereafter, like in the abovesaid "seventh" case, the 7th degree tone data is set in the register X, to carry out the semi-tone down sub-routine, and with this the processing completes.
If the result of judgment as to whether the chord type is minor seventh with 5th degree flat is "no" N, then whether the value of the register A is "07" in hexadecimal notation is checked to judge whether the chord type is "diminished" (Dim). If the result of this judgment is "yes" Y, the third degree data is set in the register X as in the case of "minor" stated above, and thus the semi-tone down sub-routine is carried out. Next, as in the abovesaid case of "minor seventh with 5th degree flat", the 5th degree data is set in the register X, and the semi-tone down sub-routine is carried out. Thereafter, the 7th degree data is set in the register X, and the processing will move on to such a whole tone down sub-routine as will be described later with respect to FIG. 11, and the tone pitch of the key code data corresponding to the 7th degree tone in the bass tone buffer 26b is subjected to "whole tone down", and with this the processing completes.
If the result of the judgment whether the chord type is "diminished" is "no" N, then whether the value of the register A is "08" in hexadecimal notation is checked to judge whether the chord type is "augumented" (Aug). If the result of this judgment is "yes" Y, the 7th degree tone data is set in the register X as in the abovesaid "seventh" case to carry out the sub-routine for semi-tone down. Next, the 5th degree tone data is set in the register X, and the processing moves on to such a semi-tone up sub-routine as will be described later in connection with FIG. 10, and the tone pitch of the key code data corresponding to the 5th degree tone in the bass tone buffer 26b is semi-tone upped, and with this the processing completes.
If the judgment whether the chord type is "augumented" is "no" N, then it means that the chord type is either "major" (M) or sixth (6th) or "major seventh" (M7th), and the processing will end without making any such tone pitch adjustment as mentioned above. cl Semi-tone Down Sub-routine
Next, description will be made of the semi-tone down sub-routine by referring to FIG. 9.
Firstly, by adding the degree value X in the register X to the address value BASBF and thereby designating the address (BASBF+X) of the bass tone buffer 26b, a key code data corresponding to the tone of the degree to be set is read out from the bass tone buffer 26b to load it on the register A. And, whether the lower four (4) bits (note code) of the key code data of the register A is "1" in hexadecimal notation is checked to judge whether the tone name is C. If the result of this judgment is "no" N, a digit "1" is subtracted from the value of the register A, to down the tone pitch by a semi-tone. Also, if the result of the judgment is "yes" Y, a digit "5" is subtracted from the value of the register A to effect a tone down to a tone pitch B. This is because of the fact that, since "0", "D"˜"F" in hexadecimal notation are not used for the note codes as stated above, there is a difference of "5" between tone C ("1") and tone B ("C") which is a semi-tone below C.
Thereafter, the key code data in the register A which has been subjected to a semi-tone down is returned to the original address (BASBF+X) in the bass tone buffer 26b and is stored therein. And, by adding "10" in hexadecimal notation to the value of the register A, the octave value of the key code data of the register A is upped by "1", and this octave-upped key code data is stored in the address (BASBF+X+7) of the bass tone buffer 26b, and with this, the processing ends. As a result, both the key code data of the address (BASBF+X) in the bass tone buffer 26b and the key code data having the same tone name but being one octave (7-addresses) higher than said key code data have been semi-tone downed from their tone pitches.
Semi-tone Up Sub-routine
Next, the processing of the semi-tone up subroutine will be described by referring to FIG. 10.
Firstly, as in the abovesaid semi-tone down processing, a key code data corresponding to the tone of the degree to be set is taken out from the bass tone buffer 26b, and it is loaded on the register A. And, a checking is made whether the lower four (4) bits of the register A represent "C" in hexadecimal notation, to judge whether the tone name is B. If the result of this judgment is "no" N, a digit "1" is added to the value of the register A, to up the tone pitch by a semi-tone. Also, if the result of the judgment is "yes" Y, a digit "5" is added to the value of the register A to up the tone pitch to C. This is a processing which is just the reverse of the abovesaid case of semi-tone down.
Thereafter, the semi-tone-upped key code data in the register A is returned to the original address (BASBF+X) in the bass tone buffer 26b, and is stored therein. And, in the manner similar to that for the abovesaid semi-tone down, the octave value of the key code data of the register A is upped by a digit "1", and this octave-upped key code data is stored in the address (BASBF+X+7) of the bass tone buffer 26b, and with this the processing ends. As a result, the key code data of the address (BASBF+X) in the bass tone buffer 26b and the key code data having the same tone name but one octave (7 addresses) higher than that of said data both now have their tone pitches upped by a semi-tone.
Whole Tone Down Sub-routine
Next, by referring to FIG. 11, the processing of the whole tone down sub-routine will be described.
First of all, in a manner similar to that for the abovesaid semi-tone down sub-routine, a key code data corresponding to the tone of the degree to be set is taken out from the bass tone buffer 26b, and it is loaded on the register A. And, by checking whether the lower four (4) bits of the register A are is "2" or above in hexadecimal notation, to judge whether the tone pitch is C♯ or higher. If the result of this judgment is "no" N, a digit "2" is subtracted from the value of the register A to down the tone pitch by a whole tone. Also, if the result of the judgment is "yes" Y, a digit "6" is subtracted from the value of the register A to down C♯ to B, and to down C to A♯, respectively. This is because the tone pitch in this case is lower further by a semi-tone (it is "1" in note code value) than in the case of semi-tone down.
Thereafter, the whole-tone-downed key code data in the register A is returned to the original address (BASBF+X) in the bass tone buffer 26b, and it is stored therein. And, in a manner similar to that for the abovesaid semi-tone down sub-routine, the octave value of the key code data of the register A is upped by "1", and this octave-upped key code data is stored in the address (BASBF+X+7) of the bass tone buffer 26b, and with this the processing ends. As a result, the key code data at the address (BASBF+X) in the bass tone buffer 26b and the key code data having the same tone name but one octave (7addresses) higher than that of said data have now both been subjected to a whole tone down of their tone pitches.
Arpeggio Tone Set Sub-routine
Next, by referring to FIGS. 12A and 12B, description will be made of the arpeggio tone set sub-routine.
To begin with, the data of the number of the depressed keys on LK is read out from the register LKCNT, and it is loaded on the register A, and thereby the number of the depressed keys on LK is set in the register A. And, by checking whether the value of the register A is "4" or more, to judge whether the number of the depressed keys on LK is "5" or more is judged. If the result of this judgment is "no" N, the data of the register A is stored as it is in the register ARPCNT as being indicative of the number of the arpeggio tones. Also, if the result of the judgment is "yes" Y, the value of the register A is rewritten into a numeral "4", and after thus limiting the number of the arpeggio notes to "4", the data of the register A is stored in the register ARPCNT.
Next, data concerning the number of depressed keys on LK is read out from the register LKCNT, and it is loaded on the register X, and whereby the number of the depressed keys on LK is set in the register X. And, by setting the value (fixed value) of the leading address of the buffer register LKHLBF for the abovesaid tones of LK as HLB as shown in FIG. 6, and by setting the number of the depressed keys of the register X, and thereby designating the address (HLB+X-1), a key code data corresponding to the lowest tone is read out from the register LKHLBF, and this is loaded in the register A. In this instance, a key code data corresponding to the plurality of depressed keys on LK has been stored in the register LKHLBF in such a way that the data is arrayed in the high-to-low order so that a highest tone data comes at the leading address HLB. Accordingly, by designating the address (HLB+X-1) in such a manner as described above, it becomes possible to read out a key code data corresponding to the lowest tone among those depressed keys on LK.
Next, whether the value of the register A is smaller than "10" in hexadecimal notation is checked, and judgment is made whether the lowest tone belongs to the lowest octave. If the result of this judgment is "no" N, the number of the octaves which are to be downed is computed, and it is inputted into the register OCTDW. That is, it is desired that those arpeggio notes starting with the ones belonging to the lowest octave of the tone range of LK be inputted to the arpeggio tone buffer 26c, and accordingly "00" of hexadecimal notation (lowest octave in the tone sounding range) is subtracted from the higher four (4) bits (lowest depressed key octave) of the register A, to thereby obtain the difference in octave, and this difference is written in the register OCTDW as the number of octaves which are to be downed.
After completion of such write-in step, or after the judgment whether the octave is the lowest one, "00" is written in the register Y in hexadecimal notation, and a digital value "0" is set. This is intended to enable the initial arpeggio key code data to be written in the arpeggio tone buffer 26c.
Next, by reading out the initial key code data (corresponding to the lowest tone) from the register LKHLBF by designating an address (HLB+X-1), it is loaded in the register A. And, by subtracting the value of the register OCTDW from the value of the register A, there is given an adjustment to effect an octave-down, and this adjusted data is set in the register A.
Next, the key code data of the register A is stored in the arpeggio tone buffer 26c. The write-in address at such time is designated by (ARPBF+Y) if the leading address value (fixed value) of the buffer 26c is assumed to be ARPBF and the value of the register Y is assumed to be Y as shown in FIG. 4. However, as stated above, since the value of the register Y is "0", the leading address ARPBF of the buffer 26c will become the initial write-in address.
Next, the values of the register X and of the register Y are upped by a digit "1", respectively, to advance the read-out address and the write-in address by "1", respectively.
Thereafter, by checking whether the value of the register Y is greater than "3", it is determined whether the transfer of the key code data for four (4) tones has ended. If the result of this judgment is "no" N, such a data transfer step from the register LKHLBF to the arpeggio tone buffer 26c as mentioned above is repeated. And, repeating such a data transfer step inclusive of the first one four (4) times, this represents that key code data for four (4) tones have been stored in the arpeggio tone buffer 26c, and the judgment whether the transfer of four (4) tones has been finished will become "yes" Y.
In such a data transfer processing as mentioned above, it will be noted that, even in case the number of the depressed keys on LK (the value of the register X) is greater than "4", there are stored in the arpeggio tone buffer 26c only those key data of no more than four (4) tones counting from the low tone side in the register LKHLBF. If the number of the depressed keys on LK is four (4), key data for four (4) tones in the register LKHLBF is stored in the buffer 26c. In case, however, the number of the depressed keys on LK is smaller than four (4), e.g. two (2), there is also stored in the buffer 26c key data for two tones which are irrelevant and not contained in the register LKHLBF in addition to the two depressed key data to fill the four-tone space. However, such irrelevant data are erased in the subsequent data write-in processing, and accordingly it provides no problem.
Now, when the judgment whether the transfer of four (4) tones has ended becomes "yes" Y, "00" in hexadecimal notation is written in the register X and thus a digital value "0" is set, and concurrently the number of arpeggio tones is set in the register Y from the register ARPCNT.
Next, by designating an address (ARPBF+X), a first key code data (corresponding to the highest pitch tone) is read out from the arpeggio buffer 26c, and it is inputted in the register A. And, by checking whether the value of the register A is greater than "41" in hexadecimal notation, to judge whether the tone pitch of the data of the register A is higher than C 6 note. This is intended so that the tone pitches of the respective tones are upped octave by octave until the highest octave is reached for each tone, and when the highest octave is reached, the same octave is to be repeated thereafter. If the result of this judgment whether the tone pitch is higher than C 6 is "yes" Y, no octave-up processing is required, and accordingly the key code data of the register A is stored as it is (i.e. without undergoing an alteration of octave) in the address (ARPBF+Y) of the arpeggio tone buffer 26c. Also, if the result of judgment is "no" N, "10" in hexadecimal notation is added to the value of the register A to correct this latter value for one octave up, and this modified data is stored in the address (ARPBF+Y) of the buffer 26c.
Here, the write-in address of the arpeggio tone buffer 26c is designated by (ARPBF+Y), and accordingly, as stated above, even if the number of the depressed keys on LK (i.e. the value Y of the register Y) is "2", the abovesaid irrelevant data are substituted by the key code data which are freshly written in, so that such irrelevant data will not remain in the buffer 26c.
Next, the values of the register X and of the register Y are upped by "1" respectively, to advance the read-out address and the write-in address by "1" respectively.
Thereafter, whether the value of the register Y is greater than "15" is checked, and thus whether the arpeggio tone buffer 26c is filled up fully with key code data is judged. If the result of judgment is "no" N, such data reading-out and storing operations as those mentioned above are repeated. And, by repeating such data reading-out and storing operations including the first one 16 Y O times, the buffer 26c becomes filled up. Here, Y O represents the initial value of the register Y corresponding to the value of the register ARPCNT. When the buffer 26c becomes full, the judgment whether it is filled up becomes "yes" Y, and the processing ends with this.
Interruption Routine
Next, FIG. 13 is referred to now for the description of the interruption routine processing.
As stated above, the tempo timer 76 is arranged to apply interruptions twelve (12) times at equal intervals within a single beat (quarter note length). However, each time a command for interruption is generated, processing will move from the abovesaid main routine to the interruption routine.
In the interruption routine, firstly the contents of the respective registers which have been used in the main routine are saved, and thereafter whether the rhythm run flag RHYRUN is not "0" is checked, and thus judgment is made whether the mode is rhythm run (whether the rhythm start/stop switch is set to its start position). If the result of this judgment is "no" N, processings for generating (sounding) the rhythm tones, chord tones, bass tones and arpeggio tones are not required, and accordingly the contents of the respective registers are restored to end the interruption routine, and with this the processing is returned to the main routine.
If the result of judgment whether the switch is set to "rhythm run" is "yes" Y, the processing will move on to that of outputting the rhythm tones. This processing consists of giving reference to the rhythm pattern memory 24c by making use of the leading address register RHYROM, the address pointer RHPNT, the intra-beat timing counter TMPCNT, and the beat end flag RHHEND, and of supplying, to the rhythm tone forming circuit 74 via the rhythm interface 72, the musical instrument type designation data corresponding to the rhythm instruments (percussion instruments) which are to produce sounds and the sounding controlling data. Whereby, it becomes possible to generate the rhythm tones at given intra-beat timings. It should be noted here that this rhythm tone output processing is similar to the bass tone output processing which will be described later, except that there are no off-timing processing and key-off processing.
Next, the processing moves on to the processing for outputting the chord tones. This processing consists of giving reference to the chord pattern memory 24b by utilizing the leading address register CHDROM, the address pointer CDPNT, the intra-beat timing counter TMPCNT, and the beat-end flag CDHEND, and thereby supplying the chord data set in the chord buffer 26al to the LK music tone forming circuit 42 via the LK interface 40. Whereby, it becomes possible to generate chord tones at given intra-beat timings. It should be noted here that this chord output processing is similar to the bass tone output processing which will be described later, except that no selection of key code data for being sounded is carried out and that the key code data for a plurality of tones are outputted simultaneously.
Next, the bass tone output sub-routine is carried out to enable the generation of bass tones at given intrabeat timings. Its details will be described later with respect to FIGS. 14A and 14B.
Next, a sub-routine of arpeggio conversion and a sub-routine of arpeggio tone output are carried out successively to enable the generation of arpeggio tones at given intra-beat timings, and the details thereof will be described later in connection with FIGS. 15A to 17.
Thereafter, the intra-beat timing counter TMPCNT is upped by one count. And, the intra-measure timing counter TIMING is also upped by one count.
Next, by checking whether the value of the counter TMPCNT has reached "12", judgment is made whether a "beat over" has occurred. If the result of this judgment is "no" N, the contents of the respective registers are restored to return to the main routine. Also, if the result of the judgment whether a "beat over" has occurred is "yes" Y, the beat-end flags RHHEND, CDHEND, BAHEND and ARHEND are reset, respectively, and thereafter the counter TMPCNT is reset.
Thereafter, checking is made whether the value of the counter TIMING is in agreement with the value (which is 36 for 3 beats, and 48 for 4 beats) of the maximum timing register TMPMAX to judge whether there has occurred a "measure over", and if the result of this judgment is "no" N, the contents of the respective registers are restored to return to the main routine. Also, in case the result of judgment whether there has occurred a "measure over" is "yes" Y, the counter TIMING is reset, and thereafter the respective registers are restored to return to the main routine.
According to the above-mentioned interruption routine, it is possible to generate rhythm tones, chord tones, bass tones and arpeggio tones twelve (12) times within a single beat, respectively. However, at which one to be generated is determined by the rhythm pattern, the chord pattern, the bass pattern and the arpeggio pattern, respectively, which are read out from the pattern memory 24 in accordance with the type of the rhythm selected.
Bass Tone Output Sub-routine
Next, bass tone output sub-routine processing will be described by referring to FIGS. 14A and 14B.
Firstly, whether the beat-end flag BAHEND is not "00" in hexadecimal notation is checked to thereby judge whether there is a "beat end". The flag BAHEND is arranged so that "0D" in hexadecimal notation is set at the time of detection of the beat-end flag data, and, on the other hand, "0F" in hexadecimal notation is set at the time of detection of the return flag data. Accordingly, if the result of the judgment whether there is a "beat end" is "yes" Y, this means that either the beat-end flag data or the return flag data has been detected, and if the result is "no" N, it means that none of these flag data has been detected yet.
Let us here assume that the result of the judgment whether there is a "beat end" is "no" N. Whereupon, a pointer value (a relative address within the bass pattern memory 24a) is read out from the address pointer BAPNT, and it is inputted in the register Y. And, by adding the value of the register Y to the value of the leading address of the pattern memory area which has been set in the register BASROM in correspondence to the type of the rhythm selected and thus designating an address, there is read out a bass pattern data corresponding to the selected type of rhythm from the bass pattern memory 24a and it is inputted in the register A. In this instance, what is written in the register A is the data of the first byte among a set of two bytes, and includes a sounding controlling data (higher three bits) and a sounding timing data (lower four bits).
Next, judgment is made whether there is an agreement between the sounding timing value indicated by the lower four bits of the register A and the value of the intra-beat timing counter TMPCNT. If the result of this judgment is "yes" Y, the pointer value of the register Y is upped by "1".
Next, whether the state flag PKWON is at "1" level is checked, and thus whether the walking bass selection switch is set "on" is judged. If the result is "no" N, the pointer value of the register Y is upped further by "1", and thereafter the pointer value of the register Y is stored in the pointer BAPNT, and with this the processing completes. In case the walking bass selection switch is not turned "on" unlike the above, the value of the pointer BAPNT is set to correspond to the data which is to be read out next.
On the other hand, if the result of the judgment whether the walking bass selection switch is turned "on" is "yes" Y, the processing moves on to that of storing the sounding controlling data. That is, by masking the lower four bits of the register A, the higher three (3)-bit sounding controlling data (tone volume data ACC and mute data M) are derived, and they are stored in the memory section BASRAM 2 in the sounding base/arpeggio data memory 28.
Next, by designating an address by adding the pointer value of the register Y which has been previously upped by "1" to the leading (top) address value of the pattern memory area which has been set in the register BASROM, the bass pattern data is read out from the bass pattern memory 24a, and it is loaded in the register A. In this case, what is written in the register A is the data of the second byte among the data of the two bytes, and it includes a tone pitch data (higher four bits) and a tone duration data (lower four bits).
Next, by effecting a 4-bit right-shifting of the data of the register A, the tone pitch data of the higher four bits is derived, and it is inputted in the register X.
As stated above, a tone pitch data indicates either one of the addresses of 0-15 in the bass tone buffer 26b. Accordingly, by designating an address by adding the value of the register X to the leading address value BASBF of the buffer 26b, a key code data corresponding to the abovesaid tone pitch data is derived from the buffer 26b, and it is set in the register A.
Next, the key code data of the register A is transferred to the memory section BASRAM 1 in the memory 28, and it is stored therein.
Subsequently, the sounding controlling data of BASRAM 2 and the key code data of BASRAM 1 are outputted to the bass interface 44. The key code data supplied to the interface 44 is written in the "on-key" code register 46, and it is transferred, by the assignment controlling circuit 50, to a register section in the key code/key-on register 52 and corresponding to the first music tone forming channel. As a result, a key code data corresponding to the bass tone which is to be sounded and a key-on data have been stored in the register section corresponding to the first music tone forming channel, and these data are supplied to the bass tone forming circuit 56. Also, the sounding controlling data which has been supplied to the interface 44 is stored in the sounding controlling data register 54, and it is supplied from this register to the bass tone forming circuit 56. Accordingly, the bass tone forming circuit 56 forms a bass tone signal in the first music tone forming channel in accordance with the key code data, the key-on data and the tone volume data ACC supplied from the interface 44, and in accordance with this bass tone signal, a bass tone is generated from the loudspeaker 38.
Next, the processing will be switched over to the off-timing processing A. In this processing, by first designating an address by adding the pointer value of the register Y to the pattern top address value which has been set in the register BASROM, a bass pattern data is read out again from the bass pattern memory 24a, and it is inputted in the register A. At such time, what are inputted in the register A are a tone pitch data and a tone duration data.
Next, by taking an AND of the data of the register A and "F" in hexadecimal notation bit by bit, there is derived a lower four bit tone duration data and it is loaded in the register X. And, as shown in FIG. 2, by assuming the top address value (fixed value) of the note duration table 22c as being OFTIME, and by assuming the value (relative address in Table 22c) of the register X as being X, and by thus designating an address (OFTIME X), a time length data corresponding to the abovesaid tone duration data is read out from the Table 22c, and it is inputted in the register A.
Next, by adding the value of the register A to the value of the intra-measure timing counter TIMING, there is sought an off-timing value, and it is inputted in the register A.
Next, checking is made to see if the value of the register A (off-timing value) is greater than the value (36 if three beats, and 48 if four beats) of the maximum timing register TMPMAX, to judge whether it exceeds the length of one measure. If the result of this judgment is "no" N, the off-timing data of the register A is stored in the memory section BASRAM 0 of the memory 28. Also, if the result of the judgment is "yes" Y, the value of the register TMPMAX is subtracted from the value of the register A, to correct the value of the off-timing, and this corrected off-timing data is stored in the memory section BASRAM 0 . At any rate, the off-timing data which is stored in BASRAM 0 indicates the timing of starting a sustain following the starting of sounding the bass tone by an intra-measure timing value (if three beats, either one of 0˜35, and if four beats, either one of 0˜47).
In the stage after the storage of the off-timing data, the pointer value of the register Y is upped by "1" in a way similar to that for the above-mentioned instance wherein the condition was not "walking bass switch on", and this "1"-upped pointer value is stored in the pointer BAPNT, and the processing ends with this.
The above description represents the processing that, when a certain interruption is applied, a bass pattern data is read out, showing that an agreement in intra-beat timing is obtained (i.e. there is present a bass tone which is to be sounded). However, also when a next interruption is applied, a bass pattern data is read out in a manner similar to that mentioned above, and it is inputted in the register A. The bass pattern data which is read out at such time represents a data next to the preceding read-out data, since the pointer value has been upped by "1" as noted in the lower part of FIG. 14B.
Next, as in the preceding procession, the lower four bits of the register A are compared against the contents of the counter TMPCNT, to judge whether there is an agreement in the intra-beat timing. If the result of this judgment is "no" N, checking is made whether the value of the register A is over "D" in hexadecimal notation, and judgment is made whether there is a flag data (either beat-end flag data or return flag data).
In this instance, if the data of the register A is a sounding timing data, the result of judgment whether there is a flag data will be "no" N, and thus the processing will move over to off-timing deriving. This processing is to derive the off-timing data which has been stored previously in the memory section BASRAM 0 of the memory 28 and to load it in the register A.
Next, judgment is made whether the sounding timing value of the register A is in agreement with the value of the intra-measure timing counter TIMING. If the result of this judgment is "no" N, it is considered that the time has not yet come to start a sustain, and thus the processing ends without going to the key-off processing B (FIG. 14B right down).
Thereafter, interruption will be applied several times. However, if no intra-beat timing coincidence nor intra-measure timing coincidence is obtained at any one of the interruptions, the processing will end without passing through a key-off processing B in a manner similar to that mentioned above. And, during the period in which interruption is repeated as stated above, the value of the intra-measure timing counter TIMING continues to increase, and accordingly there will come eventually a time at which an agreement in intra-measure timing is obtained.
When a coincidence in intra-measure timing is obtained, the processing will move on to the key-off processing B. That is, a key code data which has been previously stored in the memory section BASRAM 1 of the memory 28 is derived, and it is inputted in the register A. Next, checking is made whether the register A is not "0" to judge whether there is a key code data. Usually, the result of this judgment is "yes" Y, and thus the key code data of the register A is outputted to the bass interface 44. The key code data which has been supplied to the interface 44 is stored in the off-key code register 48, and is transferred by the assignment controlling circuit 50 to the register section within the register 52 and corresponding to the first music tone forming channel. As a result, in the register section corresponding to the first music tone forming channel, the key-on data which has been previously stored is substituted by a key-off data, and this key-off data is supplied to the bass tone forming circuit 56.
The bass tone forming circuit 56, upon its receipt of a key-off data, performs a sustain control to gradually decay the amplitude envelope of the bass tone signal which is being generated. Due to this sustain control, the bass tone which is being generated will decay gradually instead of vanishing abruptly. If, in this case, the mute data M which has been stored in the sounding controlling data register 54 is "1", a sustain controlling will be carried out in such a manner that the decay period of the bass tone will become shorter as compared with the instance where that data is "0".
After the sustain control of the bass tone is started in such a manner as mentioned above, "00" in hexadecimal notation is written in the memory section BASRAM 1 of the memory 28 to clear the key code data, and with this the processing ends.
In the above-mentioned processing, the data which is read out into the register A is mentioned as being a sounding timing data. In case this is a beat-end flag data (which is "0D" in hexadecimal notation), the operation will become as stated below. That is, since the result of judgment whether there is an agreement in intra-beat timing becomes "no" N, the judgment whether there is a flag data will become "yes" Y. Next, checking is made whether the value of the register A is "0F" in hexadecimal notation and judgment is made whether there is a return flag. Since the result will be "no" N, the beat-end flag data of the register A is set at a beat-end flag BAHEND. And, the pointer value of the register Y is upped by "1", and this one-upped pointer value is set in the pointer BAPNT.
Thereafter, an off-timing data is derived in such a manner similar to that mentioned above, and judgment is made whether there is an agreement in intra-measure timing. If several interruptions are assumed to be required before the start of key-off, the result of said judgment will become "no" N, and with this the processing ends.
When a next interruption is applied, the judgment whether there is a beat-end shown in the upper part of FIG. 14A becomes "yes" Y. This is because the beat-end flag BAHEND has been set at the time of the preceding interruption.
When the judgment whether there is a beat-end is "yes" Y, an off-timing data is derived as in the preceding case described above, and a judgment is made whether there is an agreement in the intra-measure timing, but the result of this judgment will become "no" N as in the preceding case, and with this the processing ends.
As stated above, once a beat-end flag BAHEND is set, the routine of FIGS. 14A and 14B will become terminated substantially with a brief processing including the deriving of the off-timing data and also the judgment on an agreement of the intra-measure timing. Such a brief processing is repeated until the count value of the intrabeat timing counter TMPCNT becomes "12" and thus until the beat-end flag BAHEND is reset in the routine of FIG. 13. It should be understood that during the period in which such a brief processing is repeated, the intra-measure timing counter TIMING continues to show an increase in its count value for each interruption alike the counter TMPCNT, and accordingly, when an agreement of intra-measure timing is obtained, there will be carried out a key-off processing B in the same way as that described above.
When, after the beat-end flag BAHEND is reset in the routine of FIG. 13, a next interruption is applied, the judgment whether there is a beat-end as shown in the upper part of FIG. 14A becomes "no" N, and there is performed a read-out of a pattern data in the same way as described above. In this case, since the value of the pointer BAPNT has been upped by "1" after the above-mentioned setting of the beat-end flag, there is read out a sounding controlling and sounding timing data next to the beat-end flag data. Based on this read-out data, there is made a judgment whether there is an agreement in intra-beat timing. If the result of this judgment is "yes" Y, a sounding controlling data is written in the memory section BASRAM 2 of the memory 28, and concurrently a key code data is written in the memory section BASRAM 1 thereof, respectively, in the same way as described above, and they are outputted to the interface 44. In this case, in the interface 44, the assignment controlling circuit 50 assigns a key code data and a key-on data to a register section in the key code/key-on register 52 and corresponding to the second music tone forming channel. Accordingly, the bass tone forming circuit 56 will form a bass tone signal in the second music tone forming channel, and a bass tone corresponding to this bass tone signal is sounded from the loudspeaker 38.
As described above, the current bass tone signal is formed in a music tone forming channel which is different from the channel for the preceding bass tone signal, and therefore, the current bass tone can be sounded out during the period in which the preceding bass tone is sustained.
Thereafter, in a manner similar to that described above for the preceding case, there are performed such processings as the off-timing processing B and the pointer value upping processing.
And, when there is obtained an agreement of intrameasure timing at the end of several times of interruption, there is performed a key-off processing B for the current bass tone.
During the course of progress of the bass tone generating operation in such a manner as described above, there is read out a return flag data into the register A from the bass pattern memory 24a. The judgment made then whether there is an agreement of intra-beat timing will be "no" N. A further judgment whether there is a flag data will give "yes" Y. Next, checking is made whether the value of the register A is "0F" in hexadecimal notation to judge whether there is a return flag data. Since the result of judgment is "yes" Y, "FF" in hexadecimal notation (data of "1" in all bits) is set in the register Y.
Next, the return flag data of the register A is set in the beat-end flag BAHEND. And, by upping the value of the pointer by "1" by adding "1" to the value ("FF" in hexadecimal notation) of the register Y, the pointer value will become "00" in hexadecimal notation, and this pointer value is set in the pointer BAPNT.
Thereafter, an off-timing data is derived to judge whether there is an agreement of intra-measure timing, and if the result is "no" N, the processing ends at this, but if "yes" Y, the processing will terminate after passing through a key-off processing B.
Since, in the next interruption, the beat-end flag BAHEND having been set, the processing will be similar to that for the above-mentioned beat-end flag setting. Such an operation will be repeated until the beat-end flag BAHEND is reset. And, when the beat-end flag BAHEND is reset, it should be noted that, since the pointer BAPNT is at "00" in hexadecimal notation from the next interruption and onwards, there is read out a bass pattern data from the top address of the bass pattern memory 24a, and thereafter, a bass tone generating operation similar to that mentioned above will be repeated.
Sub-routine for Arpeggio Conversion
Next, description will be made of a sub-routine processing for arpeggio conversion by giving reference to FIGS. 15A and 15B.
Firstly, a check is made whether the value of the beat-end flag ARHEND is not "00" in hexadecimal notation, and "0D" in hexadecimal notation is set at the time of detection of a beat-end flag data, and concurrently "0F" in hexadecimal notation is set at the time of detection of a return flag data. If the result of judgment whether there is a beat-end is "yes" Y, this means that a beat-end flag data or a return flag data has been detected. If the result is "no" N, it means that none of these data has been detected.
Assuming that the result of judgment whether there is a beat-end is "no" N, a pointer value (a relative address in the arpeggio pattern memory 24d) is read out from the address pointer ARPNT, and it is inputted in the register Y. And, by designating an address by adding the value of the register Y to the pattern top address value which has been set in the register ARPROM correspondingly to the selected type of rhythm, an arpeggio pattern data corresponding to the selected type of rhythm is read out from the arpeggio pattern memory 24d, and it is loaded in the register A. In this case, what is written in the register A is the data of the first byte among the two bytes, and it includes a sounding controlling data (upper four bits) and a sounding timing data (lower four bits).
Next, the data of the register A is transferred over to the register X. And, by taking an AND of the data of the register A and "0F" in hexadecimal notation, there is derived a sounding timing data of the lower four bits, and this is inputted in the register A.
Next, judgment is made whether the value of the register A is in agreement with the value of the intra-beat timing counter TMPCNT. Assuming that the result of this judgment is "yes" Y, checking is then made whether the state flag ARPON is not "00" in hexadecimal notation, and judgment is made whether the arpeggio selection switch is turned "on". If the result of this judgment is "no" N, the processing is done for upping the value of the pointer of the register Y twice, and the operation will return to the reading-out of the pattern data. In this case, the reason for upping the pointer value of the register Y by "2" is that, since the arpeggio pattern data is stored as a set of two bytes, it is necessary to advance the address value by "2" in order to read out the data which is in the first byte among the next two bytes forming another set.
Thereafter, in a manner similar to that described above, an arpeggio pattern data is read out. Then, by comparing the value indicated by the sounding timing data among the data thus read out, against the value of the counter TMPCNT to judge whether there is an agreement of intra-beat timing, and if the result of this judgment is "yes" Y, another judgment is made whether there is an "arpeggio-on", and if this result is "no" N, the pointer value is upped again by "2".
Such a pointer value upping operation can be repeated up to four (4) times at most so long as there is obtained an agreement of intra-beat timing and also so long as the state of the switch is not "arpeggio-on". That is, in this instant embodiment, there are provided four (4) music tone forming channels for arpeggio, and it is possible to sound at most four (4) arpeggio tones simultaneously at a given intra-beat timing. Therefore, in the arpeggio pattern data, there is the possibility that data of two bytes as a set at a same intra-beat timing are contained for four (4) tones. In such a case, the operation as mentioned above is repeated four (4) times, and the pointer value will advance by eight (8).
Now, let us here assume that the result of the abovesaid judgment whether there is the "arpeggio-on" is "yes" Y. Then, the contents of the register X are transferred over to the register A, and thereafter a scanning of channels is performed. This is to judge which one of the four (4) music tone forming channels is pointed to by the channel data CH contained in the arpeggio pattern data. Thus, judgment is made first whether it is the first channel. If the result of judgment is "no" N, judgment is made whether it is the second channel, and if the result is "no" N, judgment is made whether it is the third channel, and if the result is again "no" N, the channel in question is judged to be the fourth channel.
Concretely speaking, as shown in FIG. 3, a channel data CH is comprised of the second and third bits as counted from the highest bit in one byte (consisting of eight bits), and they are provided with "00", "01" "10" and "11" binary codes corresponding to the channels of 1, 2, 3 and 4, respectively. In case of the judgment whether it is the first channel, an AND of the data of the register A and "60" in hexadecimal notation (=01100000 in binary) is taken to check whether the result will be "00" in hexadecimal notation. In case of the judgment whether it is the second channel, an AND of the data of the register A and the hexadecimal "40" (=binary 01000000) is taken to check whether it will be hexadeximal "00". In case of the judgment whether it is the third channel, an AND of the data of the register A and the hexadecimal "20" (=binary 00100000) is taken to check whether it will be hexadecimal "00".
If, as the result of the abovesaid judgment of channel, the first channel is the result, hexadecimal "00" is inputted in the register ARCH. If the result of judgment is the second channel, hexadecimal "04" is inputted in ARCH. If the result is noted to be the third channel, hexadecimal "08" is inputted in ARCH. If the channel is judged to be the fourth one (meaning that it is judged as not being the third channel), hexadecimal "0C" is inputted in ARCH.
After having inputted a channel-designating data in the register ARCH in such a manner as described above, the processing will move on to an arpeggio tone storing sub-routine. This sub-routine is intended to store arpeggio data in the memory sections (ARPRAM 0 ˜ARPRAM 3 , ARPRAM 4 ˜ARPRAM 7 , ARPRAM 8 ˜ARPRAM 11 or ARPRAM 12 ˜ARPRAM 15 ) contained in the sounding bass/arpeggio data memory 28 and corresponding to the channel indicated by the register ARCH. The details thereof will be described later with respect to FIG. 16. It should be noted here that, in the arpeggio tone storing sub-routine, the pointer value of the register Y is upped by "2".
Upon completion of the arpeggio tone storing sub-routine, the processing returns to the reading-out of a pattern data. There, a next arpeggio pattern data is read out, and as in the preceding case, judgment is made whether there is an agreement of intra-beat timing, and if the result is "yes" Y, a judgment whether there is "arpeggio-on" is made, and if the result is "yes" Y, there is performed the judgment of channel, and also the setting to the register ARCH is carried out. These operations, like the abovesaid pointer value upping operation in case there is no arpeggio-on, can be repeated four (4) times at most so long as there is obtained intra-beat timing agreement and so long as there is the judgment of arpeggio-on.
The above processing is one for an instance such that, when the arpeggio pattern data is read out when a certain interruption is applied, there is found an agreement in intra-beat timing (i.e. there is noted the presence of an arpeggio tone which is to be sounded). However, the operation where there is not obtained an agreement in intra-beat timing will be as follows. That is, since the result of judgment whether there is an agreement in intra-beat timing will be "no" N, checking is made whether the value of the register A is above hexadecimal "0D", and judgment is made whether there is a flag data (beat-end flag data or return flag data). If the result of this judgment is "no" N, the processing ends.
On the other hand, in case the result of the judgment whether there is a flag data is "yes" Y, checking is made whether the value of the register A is hexadecimal "0F", and judgment is made whether there is a return flag data. If the result is "no" N, the data of the register A, which is a beat-end flag data ("0D" in hexadecimal notation), is set in the beat-end flag ARHEND. And, the pointer value of the register Y is upped by "1", and this "1"-upped pointer value is set in the pointer ARPNT, and ends the processing. Also, if the result of the judgment whether there is a return flag is "yes" Y, hexadecimal "FF" is set in the register Y, and thereafter the return flag data (hexadecimal "0F") of the register A is set in the beat-end flag ARHEND. And, by upping the value of the register Y by "1", the data will become hexadecimal "00". By setting this value in the pointer ARPNT, the processing ends.
When either a beat-end flag data or a return flag data is set in the beat-end flag ARHEND as stated above, the result of judgment whether there is a beat-end in the upper part of FIG. 15A will become "yes" Y at the next interruption, and the sub-routine mentioned in FIGS. 15A and 15B ends with this. Such an operation is repeated until the count value of the counter TMPCNT reaches "12" and until the beat-end flag ARHEND is reset in the sub-routine of FIG. 13.
When the beat-end flag ARHEND is reset, the result of judgment whether there is a beat-end will become "no" N at the next interruption, and accordingly there is read out, as an arpeggio pattern data, either a data next to the beat-end flag data or a leading address data. Subsequently, such an operation as described above is repeated depending on whether or an not intra-beat timing agreement exists or whether or not arpeggio-on.
Arpeggio Tone Storing Sub-routine
Next, FIG. 16 is referred to for the description of arpeggio tone storing sub-routine.
Firstly, by designating an address by adding the value of the register Y to the pattern top address value which is set in the register ARPROM in correspondence to the selected type of rhythm, there is read out an arpeggio pattern data corresponding to the selected type of rhythm from the arpeggio pattern memory 24d, and it is inputted in the register A. The one-byte data which is entered in the register A at such time contains the sounding timing data (lower four bits) for which an intra-beat timing agreement has been obtained in the routine of FIG. 15 and also a sounding controlling data (higher four bits) associated with the above-mentioned data.
Then, by designating an address (ARM+ACH+3) by assuming that the top address value (fixed value) of the arpeggio data memory section is ARM as shown in FIG. 5, and that the value of the channel designating data in the register ARCH is ACH, the sounding controlling data (tone volume data ACC, channel data CH and mute data M) which is derived from the register A is stored in the memory section (ARPRAM 3 , ARPRAM 7 , ARPRAM 11 or ARPRAM 15 ) corresponding to the designated channel.
Next, after upping the pointer value of the register Y by "1", and by designating an address by adding the pointer value of the register Y to the pattern top address value which has been set in the register ARPROM, there is read out an arpeggio pattern data from the memory 24d, and it is inputted in the register A. At such time, the one-byte data which is set in the register A is one next to the one-byte data which has been read out precedingly thereto, and it contains a tone pitch data (higher four bits) and a tone duration data (lower four bits).
Next, by shifting the data of the register A by four bits toward the right, a tone pitch data of higher four (4) bits is derived, and this tone pitch data is transferred from the register A to the register X. Here, the tone pitch data is indicative of either one of the address of 0˜15 in the arpeggio tone buffer 26c.
Next, as shown in FIG. 4, the leading (top) address of the arpeggio buffer 26c is assumed to be ARPBF, and the value of the register X as X, and an address (ARPBF+X) is designated, whereby a key code data corresponding to the abovesaid tone pitch data is read out, and it is inputted in the register A.
Next, the key code data of the register A is stored, as an "on-key code data", in a memory section (ARPRAM 0 , ARPRAM 4 , ARPRAM 8 or ARPRAM 12 ) corresponding to the designated channel by designating an address (ARM+ACH+0).
Next, by designating an address (ARM+ACH+2), the key code data of the register A is sorted, as an off-key code data, in a memory section (ARPRAM 2 , ARPRAM 6 , ARPRAM 10 or ARPRAM 14 ) corresponding to the designated channel.
Next, by performing an address designation by adding the pointer value of the register Y to the pattern top address value which has been set in the register ARPROM, there is read out from the memory 24d an arpeggio pattern data (tone pitch and tone duration data) same as that in the preceding step, and it is inputted in the register A. And, by taking an AND of the data of the register A and hexadecimal "F", there is derived a tone duration data of the lower four (4) bits, and it is inputted in the register X.
Next, in a manner similar to that described above in connection with the bass tone output routine, an address (OFTIME+X) is designated, and whereby there is read out a time length data corresponding to the above-said tone duration data from the note duration table 22c, and it is loaded in the register A.
Next, the value of the register A is added to the value of the intra-measure timing counter TIMING, to seek the off-timing value, and it is inputted in the register A.
Next, checking is made whether the value of the register A (off-timing value) is greater than the value (if three beats, 36 and if four beats, 48) of the maximum timing register TMPMAX, to judge whether it exceeds one measure. If the result of this judgment is "no" N, the off-timing data of the register A is stored in a memory section (ARPRAM 1 , ARPRAM 5 , ARPRAM 9 or ARPRAM 13 ) corresponding to the designated channel by designating an address (ARM+ACH+1). Also, if the result of judgement is "yes" Y, the value of the register TMPMAX is subtracted from the value of the register Y to correct the off-timing value, and in a same manner as described above, this corrected off-timing value is stored in a memory section at the address (ARM+ACH+1). In any case, the off-timing data stored in the memory section at the address (ARM+ACH+1) indicates the timing at which a sustain is to be started of the arpeggio tone after its sounding has been started, by an intra-measure timing value (which, if in three beats, is either one of 0˜35, and if in four beats, either one of 0˜47).
After the storage of the off-timing data, the pointer value of the register Y is upped by "1", and with this the processing ends. By this upping of the pointer value, it will be noted that, in the sub-routine of FIG. 16, the pointer value has undergone an upping by "2". Thus, in case the processing returns to the sub-routine of FIGS. 15A and 15B, it becomes possible to read out the first byte of data (sounding controlling and sounding timing data) in the next two bytes forming a pair.
It should be understood here that the sub-routine of FIG. 16 can be carried out a plurality of times even at a single interruption. That is, let us now assume that there have been obtained intra-beat timing agreement at a plurality of times (four times at most) for plural arpeggio tones in FIGS. 15A and 15B. The sub-routine of FIG. 16 will be carried out a plurality of times corresponding to the number of times of the intra-beat timing agreement.
Arpeggio Tone Output Sub-Routine
Next, by referring to FIG. 17, description will be made of the arpeggio tone output sub-routine processing.
As a first step, hexadecimal "00" is written in the register X to set a digital value 0 therein. And, by designating an address (ARM+X+0), an on-key code data is derived from the memory section ARPRAM 0 corresponding to the first channel, and it is inputted in the register A.
Next, checking is made whether the value of the register A is not hexadecimal "00", to judge whether there is an on-key code data, and if the result is "yes" Y, the step will move on to the key-on processing route C. In this processing, the on-key code data of the register A is outputted to the arpeggio interface 58. The on-key code data which is supplied to the interface 58 is written in the on-key code register 60.
Next, by designating an address (ARM+X+3), a sounding controlling data is read out from a memory section ARPRAM 3 corresponding to the first channel, and it is loaded in the register A. And, the sounding controlling data of the register A is outputted to the interface 58. The sounding controlling data which has been supplied to the interface 58 is written in the sounding controlling data register 68.
In the interface 58, the assignment controlling circuit 64 assigns the on-key code data of the register 60 to the channel indicated by the channel data CH contained in the sounding controlling data of the register 68. That is, in this instance, a key-code data and a key-on data of the tone to be sounded are stored in the register section of the key code/key-on register 66 corresponding to the first channel, and these data are supplied to the arpeggio tone forming circuit 70. Also, to the arpeggio tone forming circuit 70, there are supplied a tone volume data ACC and a mute data M from the register 68. As a result, the arpeggio tone forming circuit 70 forms an arpeggio tone signal in the first music tone forming channel in accordance with the keycode data, the key-on data and the tone volume data ACC supplied from the interface 58, and in accordance with this arpeggio tone signal, and arpeggio tone is generated from the loudspeaker 38.
After the abovesaid sounding controlling data output processing, an address (ARM+X+0) is designated to write hexadecimal "00" in the memory section ARPROM 0 , and thereby the on-key code data is cleared. And, after upping the value of the register X by "4", checking is made whether the value of the register X is greater than hexadecimal "0C", and a judgment is made whether the processing has been completed for the four channels. In the embodiment mentioned above, however, the processing for only one channel has been completed so far, and the result of judgment becomes "no" N, and the processing returns to the reading-out of the on-key code data.
Thereafter, so long as the judgment is made that there is an on-key code data, the above-said key-on processing C is performed for the remaining second-to fourth channels (and accordingly, simultaneous sounding of up to four tones can be made at a given intra-beat timing). If, however, there is no on-key code data corresponding to the second-to-fourth channels, the result of judgment whether there is an on-key code data present after reading out an on-key code data corresponding to the second channel, will become "no" N.
In such an instance, an address (ARM+X+1) is designated to read out an off-timing data from the memory section ARPRAM 5 corresponding to the second channel, and it is inputted in the register A. And, a judgment is made whether there is an agreement between the value of the register A and the value of the intra-measure timing counter TIMING.
If the result of this judgment is "no" N, the value of the register X is upped by "4" as in the preceding case, and an on-key code data corresponding to the third channel is read out, to judge whether there is an on-key code data present. Since the result of this judgment becomes "no" N, there is read out an off-timing data corresponding to the third channel in the same way as described above, and thus a judgment is made whether there is an agreement in the intra-measure timing.
If the result of this judgment is "no" N, an operation similar to that mentioned above with respect to the data corresponding to the third channel is performed for the data corresponding to the fourth channel. In this case, by upping the value of the register X by "4" after the result of judgment whether there is an agreement in the intra-measure timing has become "no" N, it will be noted that, since the value of the register X is greater than hexadecimal "0C", the result of judgment whether the processing for the four (4) channels has ended becomes "yes" Y, and thus the processing ends.
In case there is no key-code data corresponding to the first channel in the above-mentioned embodiment, there is performed no key-on processing C, and the processing completes after performing four times such steps as the off-timing reading-out and the intra-measure timing agreement judgment.
What is described above is a processing wherein a given interruption is applied. In case, however, when interruptions have been applied several times thereafter, the result of judgment whether there is an agreement in the intra-measure timing with respect to the off-timing data corresponding to the first channel is to become "yes" Y, the processing will move over to a key-off processing D. In this latter processing, firstly an address (ARM+X+2) is designated to read out an off-key code data from the memory section ARPRAM 2 corresponding to the first channel, and it is inputted in the register A. And, checking is made whether the value of the register A is not hexadecimal "00" to judge whether there is an off-key code data present. Usually, the result of this judgment is "yes" Y, and accordingly, the off-key code data of the register A is outputted to the arpeggio interface 58. The off-key code data which has been supplied to the interface 58 is stored in the off-key code register 62, and by the assignment controlling circuit 64, it is transferred to the register section in the register 66 and corresponding to the first channel. As a result, in the register section corresponding to the first channel, the key-on data which has been previously stored is substituted by a key-off data, and this latter key-off data is supplied to the arpeggio tone forming circuit 70.
The arpeggio tone forming circuit 70, upon its receipt of a key-off data, performs a sustain (decaying) controlling of the arpeggio tone signal which is being formed in the first music tone forming channel. As a result, the arpeggio tone corresponding to the first channel and being sounded will decay gradually. It should be understood here that, in this sustain controlling step, the mute data M which is stored in the register 68 is utilized as in the case of the sustain controlling of bass tones described already.
After the abovesaid off-key code data output processing, an address (ARM+X+2) is designated to write hexadecimal "00" in the memory section ARPRAM 2 to thereby clear the off-key code data.
Next, the value of the register X is upped by "4", and the on-key code data corresponding to the second channel is read out, and a judgment whether there is an on-key code data present is made. If the result of this judgment is "yes" Y, an arpeggio tone corresponding to the second channel is generated by a key-on processing C in the same way as has been described above.
Thereafter, with respect to the data corresponding to the third and fourth channels, such processing as mentioned above are performed in accordance with the presence or absence of an on-key code and whether there is an agreement in intra-measure timing.
According to the sub-routines mentioned in FIGS. 15A to 17, not only is it possible to sound such arpeggio tones as C 2 , E 2 and G 2 in successive fashion, but also it is possible to sound these tones simultaneously. Also it should be noted that, whichever sounding type is to be taken, key code data for sixteen (16) tones spreading over a plurality of octaves are stored in the arpeggio buffer 26c, and accordingly, by appropriately setting the contents of the arpeggio pattern data, it becomes possible to make an automatic arpeggio performance of concurrent plural tones which are shifted by octaves such as C 2 +E 2 +G 2 , then C 3 +E 3 +G 3 , and then C 4 +E 4 +G 4 . | In an automatic accompaniment apparatus for electronic musical instrument capable of automatically generating accompaniment tones such as base tones, chord tones and arpeggio tones, arrangement is provided so that, at each time of depressing keys on an accompaniment keyboard, accompaniment key data for accompaniment tones which may possibly be sounded, are previously formed and secured, and the selected ones of the key data for the selected accompaniment are outputted at accompaniment tone generating timings synchronous with the rhythm. Thus bass tone, chord tones, arpeggio tones etc. may be generated in sufficient synchronous relation with a selected rhythm even by adopting a time-divisional processing using a low-speed compact computer such as a micro-computer. | 8 |
TECHNICAL FIELD
[0001] The present invention relates to a destruction system, for example provided for allowing thermal destruction of ammunition, small arms and thereto related material. The invention also relates to a corresponding method for operating such a destruction system.
BACKGROUND OF THE INVENTION
[0002] A destruction system may be used for destroying explosive objects such as e.g. ammunition, propellants or explosives, including for example old unusable or unwanted ammunition. Such a system must be robust in order to withstand the high powers of possible unwanted detonating explosives.
[0003] An example of a destruction system is disclosed in EP0898693 where munitions are loaded in a chamber through a combined inlet/outlet. The chamber is emptied after use by rotating the chamber through 180°. A similar system is disclosed in WO96/12157.
[0004] Loading of munitions into the detonation chamber is an important part of a system for a destruction process. It is desirable to enable a user-friendly and safe way to load munitions into the chamber, and also a simple way to unload destroyed munitions out from the chamber once the destruction process has been completed. Even though the above mentioned prior art shows very useful solutions for loading and unloading of objects, it would still be desirable to even further optimize a destruction system with a dedicated, user friendly loading and unloading solution.
SUMMARY OF THE INVENTION
[0005] In view of the above mentioned need, a general object of the present invention is to provide an improved destruction system which at least to some extent provides further improvements in relation to prior art.
[0006] According to an aspect of the invention, there is provided a system for thermal destruction of munitions as defined by claim 1 .
[0007] In accordance with the present invention, munitions may for example include small and medium sized ammunitions, grenades or the like, and/or propellants such as fuel, gasoline, oxidizer, rocket fuel, jet fuel etc, and/or any type of explosive object. Other types of similar objects may of course be included within the scope of the invention. Furthermore, a kiln is here understood to include a thermally insulated chamber that may produce sufficient temperature for destruction of munitions or similar. The kiln may further be configured to withstand a powerful detonation of munitions and may comprise for example a steel element for creating a robust wall. The kiln is preferably configured be operate at temperatures around e.g. 350° C. or higher.
[0008] As defined by the invention, the gate may for example be made from steel or similar for withstanding the possible detonation of explosives inside the kiln. The gate may further comprise a protruding portion for engaging with the loading tray. The engaging portion of the loading tray may for example include a hook arrangement that engages with the protruding portion of the gate.
[0009] If the kiln is in a loading position and the loading tray is rotated about its pivoting connection, then a portion of the gate may be arranged to move along an edge portion of the loading tray while rotating about its pivoting connection. At the same time, the gate is in contact with the loading tray at edge portions of the loading tray. The edge portions are advantageously such that they define an opening of the tray. This is advantageous because it allows munitions or the like to slide into the kiln as the loading tray is tilted since the gate may not block the opening of the kiln or the loading tray since it moves on the edge of the tray.
[0010] The invention is based on the understanding that loading and unloading of objects in a destruction system may be combined with locking and unlocking of the opening of the kiln. For example, by a simple motion of the loading tray for tilting an object into the kiln, the gate may automatically at the same time be locked and unlocked. Similarly, in an unloading position of the kiln reached by a rotation of the kiln, the motion of the loading tray enables extraction of waste from inside the kiln. Accordingly, advantages with the present invention include the possibility of a simple, safe and straight-forward way to load and unload munitions or material to/from a kiln of a destruction system.
[0011] According to an embodiment of the invention, the system further comprise actuators arranged to exert a force on the loading tray such that the loading tray rotates about the pivoting connection, the actuators being connected to the loading tray. The actuators may advantageously be connected to the loading tray and to a portion of e.g. the kiln or a stand connected to the kiln. The actuators may advantageously be telescoping arms. The telescoping arms may be arranged such that in a compressed state, the loading tray is tilted away from the gate. In a loading position of the kiln this may allow munitions or the like to be placed in the tray without falling out. When the telescoping arms are in an extended state, and the kiln is in a loading position, the tray may be in a position such that an object placed in the tray slides into the opening of the kiln. In the expanded state of the telescoping arms, the loading tray covers the opening of the duct. The use of telescoping arms are advantageous because they are robust, easily mounted and controlled, and quickly replaced.
[0012] In a further embodiment, the duct is arranged such that an angle larger than 90° is formed at an intersection between the kiln and the duct, and such that the duct is tilted. The intersection may be at an outer surface of the kiln and one of the sides of the duct. In this arrangement, the duct extends from the kiln in a direction such that a longitudinal central axis of the duct does not intersect with the horizontal axis of the kiln. In this way the duct extends in an essentially tangential direction from an inner surface of the kiln. This is advantageous because it facilitates loading and unloading of material/objects to/from the kiln.
[0013] In an embodiment, the kiln is rotated about the horizontal axis from the first position to the second position in a direction such that the duct travels past a vertical axis of the kiln, a rotating angle being at least 120°. In other words, the kiln is configured to be rotated in a direction such that the duct travels directly above a center point of the kiln that coincides with the horizontal axis of the kiln. This is advantageous because it allows a more efficient extraction of waste material from inside the kiln because the waste naturally falls into the duct this way. Furthermore, the rotating angle from the first loading position to the second unloading position enables simple extraction of waste because the duct is arranged close to the ground in the second position.
[0014] In an implementation of the invention, the kiln may be “shaken” for facilitating emptying of the loading tray when the kiln is in a loading position and the gate is open. This may be performed by small repetitive rotations about the horizontal axis of the kiln.
[0015] A motor is advantageously arranged and configured to supply power for rotating the kiln between the first and second position. This is advantageous because it simplifies the use of the system. The motor is advantageously an electric motor, but any other types of motors work equally well.
[0016] The heating element is advantageously arranged opposite the duct with respect to the horizontal axis. This is advantageous because it allows an object that is loaded in the kiln through the duct, when the kiln is in the loading position, to land adjacent to the heating elements.
[0017] The kiln advantageously comprises a cylindrical shape. A cylindrical shape may facilitate construction of the kiln. It further facilitates arranging the duct in the kiln since the curvature of the kiln may then only be along one circumference where the kiln is arranged. The cylindrical shape may be a circumference around an outside of the kiln in the direction of a rotation of the kiln about the horizontal axis. However, the kiln may further comprise other shapes such as a spherical, a cubic or any other suitable shape.
[0018] The destruction system is advantageously arranged on a trailer for allowing mobility of the destruction system. This way, fast and simple relocation of the system is enabled. It is further advantageous because a trailer may be towed by a standard vehicle, such as e.g. a truck. The destruction system may advantageously be dimensioned such that it is mobile by any other means, such as e.g. on a truck or on wheels mounted on a separate stand on the kiln.
[0019] The destruction system may advantageously comprise a control unit configured for controlling the actuators for controlling of the loading tray, and for controlling of the motor for controlling the rotation of the kiln. This is advantageous because it allows automatic and/or remote control of the destruction system.
[0020] According to an embodiment, the destruction system comprises a camera for monitoring an amount of waste material in the kiln. This is advantageous because it allows determining if the kiln is full or if it needs to be emptied. The camera is advantageously arranged in the loading tray.
[0021] Furthermore, the system may advantageously further comprises a control unit configured for operating the destruction system. Accordingly, operation of the system may be at least partly automated, implemented as e.g. software, hardware and a combination thereof.
[0022] The control unit is preferably a micro processor or any other type of computing device. Similarly, a software executed by the control unit for operating the inventive system may be stored on a computer readable medium, being any type of memory device, including one of a removable nonvolatile random access memory, a hard disk drive, a floppy disk, a CD-ROM, a DVD-ROM, a USB memory, an SD memory card, or a similar computer readable medium known in the art.
[0023] According to another aspect of the present invention there is provided a method for controlling of a system for thermal destruction of munitions as defined by claim 13 . This aspect of the invention provides similar advantages as discussed above in relation to the previous aspect of the invention.
[0024] According to an embodiment, the method further comprising a step of determining an amount of waste material accumulated in the kiln, and if the amount of waste material is below a predetermined limit, determining that an additional destruction process is possible.
[0025] Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled addressee realize that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which:
[0027] FIG. 1 shows an embodiment of a mobile destruction system arranged on a trailer;
[0028] FIG. 2 shows a perspective cross-sectional view of an embodiment of a mobile destruction system; and
[0029] FIG. 3 provides a flow chart illustrating loading, operation, and unloading of material from an embodiment of the invention.
DETAILED DESCRIPTION
[0030] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled addressee. Like reference characters refer to like elements throughout.
[0031] Referring now to the drawings and to FIG. 1 in particular, there is depicted a mobile destruction system 1 arranged on a trailer 2 . In FIG. 1 there is shown a kiln 3 , a loading tray 4 , a gate 5 , a duct 6 , a kiln turning actuator 7 , telescoping arms 8 , a feeding box 9 , and a stand 10 supporting the kiln 3 .
[0032] With further reference to FIG. 1 , the feeding box 9 containing munitions is placed in the loading tray 4 . However, a feeding box is not necessary for the function of the system; the munitions may also be loaded directly in the loading tray without the feeding box 9 . The kiln 3 is pivotally supported by a stand 10 and is in FIG. 1 shown in a loading position. There is further shown a horizontal axis 11 of the kiln 3 about which the kiln 3 is rotatable. The duct 6 extends outside the kiln 3 at an angle 12 different from a vertical angle and the duct 6 further has an opening covered by the gate 5 , thus the gate 5 being in a closed position.
[0033] The gate 5 is pivotally connected to a first portion 13 of the duct 6 such that the gate 5 may rotate about the axis formed by a line intersecting the first portion 13 and a periphery of the gate 5 . The loading tray 4 is pivotally connected to a second portion 14 of the duct 6 . The location of the second portion 14 is closer to the kiln 3 compared to the first portion 13 . The gate 5 has a protruding portion 15 on the gate 5 that can engage with an engaging portion 16 of the loading tray 4 to lock the gate 5 in a closed position. The loading tray 4 furthermore has edge portions 17 on which the gate 5 may slide as will be explained with reference to FIG. 3 . There is further an exhaust 20 arranged on the duct 6 . However, the exhaust may be arranged elsewhere, still connected to the kiln. For example, an exhaust may alternatively (or also) be located on the horizontal rotation axis 11 , or at another location connected to the kiln 3 . The exhaust may further be connected to a chimney. There may further be a filter or any other cleaning unit connected to the exhaust.
[0034] Referring now to FIG. 2 showing a perspective cross-sectional view of the embodiment illustrated in FIG. 1 . In FIG. 2 , an inside compartment 18 of the kiln 3 is shown with the duct 6 extending from the inside compartment 18 to the outside of the kiln 3 . A heating element 21 is located in an insulated section 22 of the kiln 3 on a side essentially opposite from the duct 6 , across from the inside compartment 18 . The heating element 21 is used for providing sufficient heat to munitions or explosives placed in the compartment such that the munitions or explosives are thermally destructed. A portion 19 inside the compartment 18 may at least partly protects the gate 5 from fragments resulting from a detonation inside the kiln 3 . The arrow indicates a rotation direction when the kiln is rotated from a first loading position to a second unloading position, as will be explained with reference to FIG. 3 .
[0035] Referring now to FIG. 3 showing a flow-chart illustrating a loading and unloading procedure for the destruction system 1 , when in use. In an initial configuration Si the kiln 3 is in a loading and operation position. In this position, the duct 6 is facing upwards and the opening of the duct 6 is closed by the gate 5 . The loading tray 4 arranged away from the opening and a feeding box 9 comprising munitions is loaded in the loading tray 4 . The amount of munitions that may be loaded for a single destruction process depends on an amount of combustible material and energy content in the munitions. In this configuration, the engaging portion 16 of the loading tray 4 engages with a protruding portion 15 of the gate 5 , as was explained with reference to FIG. 1 .
[0036] When the telescoping arms 8 are extended to an extended state S 2 , the engaging portion of the loading tray 4 releases the gate 5 , and the gate 5 slides on edge portions 17 of the loading tray 4 such that the gate 5 rotates about the pivot connection at the duct 6 and such that the gate 5 is opened. The releasing of the gate 5 is realized during the first e.g. at least 10° of rotation of the loading tray. When the telescoping arms 8 are in a fully extended state the loading tray 4 covers the opening of the duct 6 and the feeding box 9 may slide into the compartment 18 of the kiln 3 . In this configuration S 2 , the loading tray 4 is emptied. The kiln 3 may further be “shaken” for facilitating emptying of the loading tray 4 when the kiln 3 is in the loading position and the gate 5 is open.
[0037] This may be performed by small repetitive rotations about the horizontal axis 11 of the kiln. After the loading tray 4 is emptied, the loading tray 4 is moved back to the position where the gate 5 is locked, however, now the tray 4 is empty. The system 1 is now in an operation state S 3 and the kiln 3 is preferably kept in this operation position until a destruction process has been completed. Such a process may take, but is not limited to, for example 3-20 minutes. After this, the kiln may be loaded again for completing an additional destruction process.
[0038] Several destruction processes may be performed before the kiln needs to be unloaded. This is determined by an amount of waste material, such as e.g. metal pieces that is accumulated in the kiln. The amount of waste material may be determined by e.g. a camera mounted for example on the loading tray such that a user may see the inside of the kiln with the camera.
[0039] After one or several destruction processes are completed, the tray 4 is moved back to the first position S 4 in which the gate 5 is open and the loading tray 4 covers the opening of the duct 6 . In this configuration, the above-mentioned camera that may be mounted on the loading tray may be used to determine the amount of waste material accumulated in the kiln. Now, the kiln 3 is rotated in to an unloading position S 5 . The rotation is performed such that the duct 6 travels above the center of the kiln 3 . The kiln 3 is rotated at least 120°, but most preferably 150°. The loading tray 4 still closes the opening of the duct 6 .
[0040] Finally S 6 , the telescoping arms 8 are compressed and pull the loading tray 4 away from the opening of the duct 6 . Due to gravity, with the kiln 3 in the unloading position, the gate 5 will not follow the loading tray 4 as it moves away from the opening. After the loading tray 4 has been fully withdrawn, the kiln 3 can be rotated an additional angle, for example 10°, for facilitating extraction of waste material from the kiln 3 . Thereafter, the kiln 3 is emptied through the opening 23 in the duct. The kiln 3 may further be “shaken” for facilitating emptying of the kiln 3 when the kiln 3 is in the unloading position and the gate 5 is open. This may be performed by small repetitive rotations about the horizontal axis 11 of the kiln.
[0041] Variations to the disclosed embodiments can be understood and effected by the skilled addressee in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. For example, the kiln may have other shapes than illustrated in the drawings, it should also be understood that the word “munitions” includes any explosive or similar material appropriate for the destruction system, the angles mentioned in the text are not limited to the mentioned angles, for example, the kiln may be rotated an angle outside the interval 120°-160° as long as the appropriate effect occurs. In the description a feeding box is mentioned to hold the munitions. The invention is equally applicable without the feeding box, in other words, the munitions may be loaded directly in the loading tray without the feeding box. That is, the word “feeding box” may be replaced by “munitions”. The gate may further comprise an actuator for opening/closing the gate as an additional force adding to gravity. This is advantageous in case the gate is prevented from fully closing during normal operation. Furthermore, in the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. | The present invention relates to a mobile destruction system, for example provided for allowing thermal destruction of ammunition, small arms and thereto related material. The invention also relates to a corresponding method for controlling such a destruction system. | 5 |
The present invention relates to a method and a system to regulate the cooling capacity of a cooling system based on a gas expansion process.
Cooling processes based on gas expansion as cooling principle are often used where a simple and robust cooling installation is required for cooling a gas or liquid to very low temperatures, such as liquefaction of natural gas to LNG, or in cryogenic separation of air. The gas expansion process is normally based on the classic Brayton/Claude cooling process where a gaseous cooling medium goes through a work cycle based on compression, cooling, expansion and thereafter, heat exchange with the fluid that is to be cooled down. For example, for liquefaction of natural gas one can use a pre-cooled, compressed cooling medium in a gas phase, normally nitrogen or a hydrocarbon gas, or a mixture, which is pre-cooled and expanded across a turbine (for example, a radial turbine/turbo expander) or an expansion valve. The gas expansion leads to the generation of a very cold gas, or a mixture of gas and liquid, which is then used to liquefy natural gas and to pre-cool the compressed cooling gas. The gas expansion processes are relatively simple and therefore well suited for offshore installation. The processes can be based on a single expansion loop, or have two or more expansion steps coupled in parallel or in series, where the different expansion steps operate at different processing conditions (pressure, temperature, amount of flow) to increase the efficiency of the process. However, common for most of the processes is that the cooling medium is predominantly present in gas phase throughout the entire process.
As the cooling medium in gas expansion processes predominantly is present in gas phase through the entire system, the capacity regulation of these processes will often be challenging. Capacity regulation is relevant when less cooling work is required to carry out a desired cooling and/or liquefaction, for example, when less fluid that shall be cooled or condensed flows through the system, or when the fluid that shall be cooled or liquefied changes composition such that specific cooling work is reduced. Reduced capacity can, to a limited extent, be achieved by reducing the cooling medium compressor duty, for example, by variable inlet guide vanes, or speed control, or gas recycling from the discharge back to the compressor suction. However, by reducing the cooling medium volume flow rate, the expansion turbines will also provide a reduced efficiency and lower power output, or more seriously that problems will arise with control of the expansion turbine, or that the expansion turbines can not be operated over time in such an operating range. Then a situation can arise where the desired low temperature, which is necessary for the process, can not be achieved.
As a consequence of the equipment related limitations for reduction of cooling capacity in the process, another principle is normally used, in that the content of cooling medium in the closed cooling circuit is reduced (is removed permanently or temporarily from the closed loop). In this way, the operating pressure in the whole cooling circuit will be reduced, both on the high pressure side and the low pressure side. Normally, radial compressors and radial turbines are used in such cooling processes, and since compression or expansion in these machines is volume based the equipment will continue to handle a relatively fixed actual volume per unit time. By reducing the operating pressures, the same actual volume flow will be circulated, but the mass flow will be lower. In this way, a lower cooling duty is achieved with a corresponding reduction of necessary compression work, while the system will operate close to its design points.
The challenge with the latter method for capacity regulation is loss of cooling gas in case of a temporary reduction of the cooling capacity. In a large installation, one will, for example, have to use a very long time to supply large amounts of cooling medium gas of proper quality, for example, purified nitrogen, after a period with capacity reduction. Hence, it will take long time to re-establish the capacity again. Alternatives with storage or “trapping” of gas between the two pressure levels the process operates between are used, and will constitute a reasonable alternative for small installations. Other solutions comprise storage of cooling medium gas in pressure containers so that large amounts of gas can be injected into the cooling circuit when additional amounts are required.
The present invention represents a considerable optimisation of the capacity regulation of a gas expansion circuit, and in particular for large installations, such as a cooling installation for production of LNG, in that the cooling process is modified in such a way that the cooling medium gas can simply be cooled down and liquefied within a relatively short time, for intermediate storage in liquid form, and in this way be removed temporarily from the cooling circuit. The cooling circuit will then operate at a lower filling rate with subsequent lower operating pressure and reduced cooling duty. The liquefied gas can at any time be evaporated into the cooling circuit again to quickly increase the duty of the cooling installation. Storage of cooling medium gas in the liquid form at low temperature will require considerably smaller storage volumes than storage of the gas in compressed form. Liquefaction of the cooling medium gas does not require large cooling capacity in the cooling installation, as the liquefaction is carried out over a short period when the duty of the installation is being reduced and there is an excess of cooling capacity in the installation.
The invention is intended for use in all types of gas expansion circuits where the cooling medium is predominantly in gas phase throughout the entire cooling circuit, such as all types of nitrogen expansion cycles, or gas expansion cycles that use pure methane, natural gas or a mixture of hydrocarbons, and where cooling is obtained by expanding the gaseous cooling medium.
The abovementioned objects are achieved with a method for controlling the cooling capacity of a cooling system that uses a cooling circuit for gas expansion cooling by the steps:
to temporarily reduce the amount of cooling medium which is circulated in the cooling circuit, in that a fraction of the cooling medium is pre-cooled at a higher pressure and is removed from the cooling circuit, to expand the fraction of cooled cooling medium, which now is either in a gas phase or in a liquid phase, across an expansion device to a lower pressure so that at least a fraction of the cooling medium separates as a cold liquid, to separate the condensed liquid from the non-condensed gas for temporary storage in a storage unit so that the liquid is temporarily not circulated in the otherwise closed cooling circuit, thereafter to return the temporary stored liquid phase cooling medium from the storage unit to the cooling circuit when needed, and to return non-condensed gas and evaporated cooling medium from the storage unit to a suitable location in the cooling circuit.
The above mentioned objects are achieved with a system for capacity reduction in a cooling system based on gas expansion cooling comprising:
a device for cooling a gaseous cooling medium at a higher pressure in a heat exchanger or in a system of heat exchangers with the assistance of a cooling process, an outlet for a side stream of cooled cooling medium in a gas phase or in a liquid phase, an expansion device for expansion of the side stream into a stream at a lower pressure, a storage for separation of non-condensed cooling medium and temporary storage of condensed cooling medium, a return device for return of non-condensed cooling medium gas and evaporated cooling medium from the storage unit to a suitable location in the cooling system, and a return device for return of cooling medium from the storage unit to the cooling circuit when needed, in that the system is set up to temporarily remove cooling medium from the closed cooling circuit or cooling circuits.
DESCRIPTION OF THE INVENTION
The invention will now be described in more detail with reference to the enclosed figures, in which:
FIG. 1 shows the main operating principle of the invention.
FIG. 2 shows the main operating principle of the invention with alternative embodiments.
FIG. 3 shows the main operating principle of the invention with alternative embodiments.
FIG. 4 shows the main operating principle of the invention with alternative embodiments.
FIG. 5 shows the main operating principle of the invention with alternative embodiments.
FIG. 6 shows the invention for a simple gas expansion circuit.
FIG. 7 shows the invention for a simple gas expansion circuit with an alternative embodiment.
FIG. 8 shows the invention for a simple gas expansion circuit with an alternative embodiment.
FIG. 9 shows the invention for a simple gas expansion circuit with an alternative embodiment.
FIG. 10 shows the invention for a simple gas expansion circuit with an alternative embodiment.
FIG. 11 shows the invention for a simple gas expansion circuit with an alternative embodiment.
FIG. 12 shows the invention in a preferred embodiment for a two step gas expansion circuit.
With reference to FIG. 1 and FIG. 2 , the system for capacity control of the gas expansion circuit will include the following principal components:
1. Cooling of a fraction of the cooling medium at a higher pressure by means of the cooling process 100 . 2. Removal of said fraction of cooled cooling medium 12 a for expansion across the pressure reduction device 102 to a lower pressure, so that at least a small fraction of the cooling medium in the cooling medium stream 13 is liquefied at the lower pressure. 3. A storage/tank 104 for liquid phase cooling medium. 4. Separation of cooling medium stream 13 into a stream of non-condensed cooling medium gas 14 and liquid phase cooling medium, preferably this separation takes place in the cooling medium tank 104 . 5. Return of non-condensed cooling medium and also evaporated cooling medium from the tank 104 to a suitable location in the cooling system 100 . 6. A device 106 for return of cooling medium from storage tank 104 to the cooling circuit 100 according to need at load increases.
The cooling of cooling medium at the higher pressure will normally be to a lower temperature than the lowest pre-cooling temperature of the cooling medium in the main cooling circuit, i.e. that the cooling medium stream which shall be extracted for expansion across the pressure reduction device 102 to a lower pressure must normally be cooled further compared to the pre-cooling of other cooling medium streams during normal operating mode for the cooling circuit. However, the pre-cooling temperature for said cooling medium stream which is to be extracted for expansion across the pressure reduction device 102 can not be cooled down to a lower temperature than the lowest operating temperature in the cooling circuit, which normally is a returning cooling medium stream that has been expanded from a higher pressure to a lower pressure, for example as shown as stream 32 in FIG. 1 . In those cases the cooling system uses one or more multistream heat exchangers, for example, multistream plate-fin heat exchangers, the cooling can take place partly as a part of one of the main cooling circuit pre-cool pass 190 and partly as a dedicated extension 191 a of this pre-cooling pass. FIG. 1 shows this embodiment as the pre-cooling pass 190 of the cooling circuit is extended directly in the form of heat exchanger pass 191 a , while the cooling medium stream 31 of the main cooling circuit is extracted from the heat exchanger 110 a in an intermediate outlet in the heat exchanger. FIG. 2 shows an alternative embodiment where the cooling medium is first cooled down in the cooling circuit pre-cooling pass 190 and is taken out of the heat exchanger 110 a as stream 31 . A side stream 11 a is extracted from stream 31 , and is led back to the multistream heat exchanger 110 a for further cooling down in the heat exchanger pass 191 b.
FIG. 3 shows some more principle alternative embodiments which can be used individually or simultaneously. FIG. 3 shows an alternative embodiment where the cooling of said fraction of gaseous cooling medium is performed completely in a separate pre-cooling pass 191 c in one or more of said multistream heat exchangers in the heat exchanger system. Alternatively, the cooling can also take place in a separate heat exchanger with the help of the cooling system 100 . Furthermore, FIG. 3 shows an embodiment where the cooling medium storage 104 is operated at a higher pressure than the reception pressure for return of cooling medium, in that a pressure control valve controls the pressure in 104 by restricting the flow of gas returning to the cooling circuit. FIG. 3 also shows that return of cooling medium 12 can be done by heating in a separate pass 192 in heat exchanger 110 a . A corresponding configuration can also be used if a system 110 b ( FIG. 5 ) consisting of a plurality of heat exchangers in the cooling circuit is used.
FIG. 4 shows two alternative embodiments that can be used together or individually and together with any of the alternatives described above and in the FIGS. 1-3 . In FIG. 4 the non-condensed cooling medium fraction 14 is not returned to the cooling system, but is let out of the otherwise closed cooling system as stream 14 b , for example, to the atmosphere or for use at other locations in the process plant. FIG. 4 also shows an embodiment where the system can supply other parts of the processing installation with nitrogen as stream 145 , either in the form of a liquid or a gas.
FIG. 5 shows an alternative embodiment where the cooling process uses a plurality of multistream heat exchangers as a system of heat exchangers 110 b and where the cooling medium is first cooled in the cooling circuit pre-cooling pass 190 and is taken out from one of the heat exchangers in the system 110 b as stream 31 . A side stream 11 a is extracted from stream 31 and led back to the system 110 b for further cooling in the heat exchanger pass 191 a in the subsequent heat exchanger.
FIG. 6 shows in detail the invention used in a simple gas expansion circuit, for example, a simple nitrogen expander cooling circuit. It is pointed out that the invention can also be used with other types of gas expansion circuits with different types of cooling medium and with one or more expansion steps. The cooling process starts with a gaseous stream of cooling medium 21 at a higher pressure which is pre-cooled in pass 190 in the multistream heat exchanger 110 so that pre-cooled cooling medium 31 can be expanded across the gas expander 121 to generate a cold cooling medium stream 32 at a lower pressure. The stream of cooling medium 32 is predominantly in gas phase, but in some designs a small fraction of liquid in equilibrium with the gas at the outlet of the expander/turbine can be allowed. Cold cooling medium 32 is returned to the heat exchanger 110 and provides cooling of both warm cooling medium stream 21 in the cooling medium pass 190 and cooling and/or liquefaction of process fluids 1 in one or more cooling medium passes 193 in order to provide the cooled product 7 of the process. After heating in 110 , the cooling medium stream exists as gas at the lower pressure in stream 51 . This cooling medium stream is recompressed in one or more compression steps 111 with or without inter cooling. Compressed cooling medium 20 is then aftercooled using an external cooling medium or an external cooling circuit 130 . In this context the invention starts by extracting a cooling medium stream 191 a at the higher pressure after pre-cooling in the heat exchanger pass 190 , for further pre-cooling in 191 a , until a cold cooling medium stream 12 a is formed at the higher pressure. Pre-cooled cooling medium 12 a can be in the gas or liquid state and is then expanded across a valve 102 to the lower pressure or a pressure between the higher pressure and the lower pressure, but so that the temperature is reduced and a mixture 13 of gas and at least a fraction of liquid are generated. The valve 102 will in this context also reduce the amount of cooling medium that is extracted from the cooling circuit. The gas and liquid in stream 13 are separated to a liquid fraction which can be stored in a storage tank/pressure tank/separator 104 at a suitable pressure, and a gas stream 14 which is returned at a suitable location in the cooling circuit at the lower pressure, for example, to stream 32 as shown in FIG. 5 . When the system described above extracts cooling medium through pass 191 a and via the valve 102 and a liquid is generated in 104 , the content of cooling medium in the cooling circuit is correspondingly reduced, and the capacity of the cooling installation is reduced. When the capacity shall be increased again, a suitable arrangement 106 is used to return cooling medium from the tank 104 to the cooling circuit via the connection 16 , preferably to the part of the cooling circuit that has the lower pressure, for example, as stream 17 a to the cold side 32 at the lower pressure, or a stream 17 b to the warm side 51 at the lower pressure.
The arrangement 106 for return and control of cooling medium to the cooling circuit when increased capacity is required, can in the simplest embodiment be a valve or a pump for dosing of fluid into the cooling circuit. With the use of a valve, the flow of liquid back to one of the parts of the cooling circuit, which operate at the lower pressure, can take place by means of gravitational flow as a result of a height difference, or by the storage 104 operating at a higher pressure as described in FIG. 3 and the associated description.
With the use of a pump in the arrangement 106 , it is also possible to return cooling medium to that part of the cooling circuit which operates at the higher pressure or a part operating at an intermediate pressure.
FIG. 7 shows the invention applied in the simple gas expansion circuit with an alternative embodiment for return of cooling medium from the storage 104 to the cooling circuit, with an arrangement 107 being used to supply heat to the cold liquid cooling medium in 104 . In this way, the liquid cooling medium in 104 is evaporated in a controlled way back to the cooling circuit via the gas line 14 .
FIG. 8 shows the invention used in the simple gas expansion circuit with an alternative embodiment for return of cooling medium from the storage 104 to the cooling circuit, in that an arrangement 143 external to the tank 104 is used to supply heat to the cold liquid cooling medium, and in this way the liquid cooling medium from 104 is evaporated in a controlled way back to the cooling circuit via the gas line 17 a , 17 b or a corresponding connection. The arrangement 143 can, for example, be a heat exchanger which uses air from the surroundings as a heat source, or other types of heat exchangers with an available warm medium as an energy source.
FIG. 9 shows the invention used in the simple gas expansion circuit with an alternative embodiment for return of cooling medium from the storage 104 to the cooling circuit, in that an ejector/eductor 108 is being used to obtain a controlled flow of cooling medium back to a suitable location in the cooling circuit. The ejector 108 uses a limited amount of motive gas 18 from the high pressure side of the cooling circuit, for example, from outlet 20 of the compressor or from the cooling medium stream 21 downstream the cooler 130 . The cooling medium can be returned to the part of the cooling circuit that has the lower pressure, for example, as stream 17 a to the cold side 32 at the lower pressure or as stream 17 b to the warm side 51 at the lower pressure. The ejector will give a complete or partial evaporation of the cold liquid 16 so that the returning cooling medium 17 a / 17 b is no longer a pure, cold liquid with subsequent danger of unfavourable liquid/gas flow in the cooling circuit in the period return of cooling medium is carried out.
FIG. 10 shows the invention used in the simple gas expansion circuit with an alternative embodiment for return of cooling medium from the storage 104 to the cooling circuit, with an external volume 143 being used, for example, a vessel or a pipe, preferably vertically, where a stream of liquid cooling medium 16 is led in a controlled way to said volume and is mixed with an amount of warmer gas 18 from the high pressure side of the cooling circuit, for example, from the outlet 20 of the compressor or from the cooling medium stream 21 downstream the cooler 130 . The warmer gas 18 will then supply heat so that the desired amount of cooling medium is evaporated to gas and can be returned to the part of the cooling circuit which has the lowest pressure, for example, as stream 17 a to the cold side 32 at the lower pressure or as stream 17 b to the warm side 51 at the lower pressure. This set up will lead to a complete evaporation of the cold liquid 16 so that the returning cooling medium 17 a / 17 b is no longer a cold liquid with subsequent risk of unfavourable liquid/gas flow in the cooling circuit during the period cooling medium return is carried out.
FIG. 11 shows the invention applied in the simple gas expansion circuit with an alternative embodiment for return of cooling medium from the storage 104 to the cooling circuit, with an arrangement being used where a warmer cooling medium stream 18 is supplied from a location in the cooling circuit where the pressure is somewhat higher than in the storage 104 , to be introduced in 104 via a suitable arrangement, for example, nozzles, so that the heat in the warmer gas contributes to a controlled evaporation of the cold liquid in 104 . In this way, the liquid cooling medium in 104 is evaporated back into the cooling circuit via the gas line 14 in a controlled manner.
A cooling system, for example for liquefaction of LNG, is often more comprehensive/involves more details than what is covered in the description above. However, the principles for the embodiment of the invention are the same. To illustrate this, a cooling system for liquefaction of natural gas to LNG by use of a double gas expansion circuit that uses pure nitrogen as cooling medium is shown in FIG. 12 . A gas stream 1 comprising natural gas which shall be liquefied is cooled in more than one step in the heat exchanger 110 in that the gas is pre-cooled to an intermediate temperature 4 where heavier hydrocarbons can be separated as liquid in a separator or column 160 . Pre-cooled gas 6 is then conducted back to the heat exchanger 110 for further cooling, condensing and subcooling, until the liquid exists as LNG in the product stream 7 . The cooling circuit now comprises a gaseous cooling medium stream 21 at a higher pressure which is divided into two parts 30 and 40 which are pre-cooled to different temperatures in the heat exchanger 110 . Stream 30 is pre-cooled to a lower temperature than the temperature in 30 and is expanded across gas expander 121 to generate a cold cooling medium stream 32 at a lower pressure. The cooling medium stream 32 is predominantly in a gas phase, but in some designs a small liquid fraction in equilibrium with the gas at the outlet of the expander/turbine can be allowed. Cold cooling medium 32 is returned to the heat exchanger 110 to contribute with cooling. Stream 40 is pre-cooled to a temperature lower than the temperature in 32 and is expanded across a gas expander 122 to generate a cold cooling medium stream 42 at a lower pressure. The cooling medium stream 42 is predominantly in a gas phase, but in some designs a small liquid fraction in equilibrium with the gas at the outlet of the expander/turbine can be allowed. Cold cooling medium 42 is returned to the heat exchanger 110 to ensure the cooling in the lowest temperature range. After warming up in 110 the cooling medium streams now exist as the gas streams 33 and 43 at the lower pressure. These gas streams can then be recompressed in one or more compression steps with or without intercooling. It must be pointed out that the splitting of the cooling medium stream must not necessarily take place before the heat exchanger 110 , but can also take place as an integrated part of the heat exchanger 110 in that the pass divides the gas stream for outlet of a stream 31 in an intermediate outlet and for further cooling of the remaining gas 41 . In the same way, the heating of the cold gas 32 and 42 can occur in such a way that the streams are mixed as an integrated part of the exchanger. In the same way as for the simple gas expansion circuit the embodiment of the invention starts in this context by extracting a cooling medium stream 191 a at the higher pressure after pre-cooling in the heat exchanger pass 190 , for further pre-cooling in 191 a until a cold cooling medium stream 12 a at the higher pressure exists. It is pointed out that all of the methods for separation of a side stream of cooling medium for further cooling described above and in the FIGS. 1-3 can be used in this set up also. Pre-cooled cooling medium 12 is expanded across a valve 102 to the lower pressure, or a pressure between the higher pressure and the lower pressure, but so that the temperature is reduced and a mixture 13 of gas and at least a fraction of liquid is generated. In this connection, the valve 102 controls the amount of cooling medium which is extracted from the cooling circuit. The gas and liquid in stream 13 are separated to a liquid fraction which can be stored in a storage tank/pressure tank/separator 104 at a suitable pressure, and a gas stream 14 at the lower pressure which is returned at a suitable location in the cooling circuit, for example, to stream 32 or 42 via 14 b and 14 a , respectively. When the system described above extracts cooling medium through pass 191 a and via the valve 102 and liquid is generated in 104 , the content of cooling medium in the cooling circuit is correspondingly reduced and the capacity of the cooling installation is reduced. When the capacity shall be increased again, a suitable arrangement 106 to return cooling medium 16 from 104 to the cooling circuit is used, preferably to the part of the cooling circuit that has the lower pressure, for example, as stream 17 a to the cold side 32 at the lower pressure, or as stream 17 c to the cold side 42 at the lower pressure, or as stream 17 b to the warm side 51 at the lower pressure. All the alternative methods described above for return of the cooling medium to the cooling circuit can also be used.
It must be pointed out that in all embodiments of the invention the gas stream 14 can be returned to other locations in the cooling circuit than those described through the figures and the examples given above, as long as the pressure is low enough, and the invention is not limited to the examples described here.
It is pointed out that in all embodiments of the invention the cooling medium 17 can be returned to other locations in the cooling circuit than those described in the figures and in the examples given above as long as the pressure is sufficiently low with regard to the method which is used for the return, and the invention is not limited to the examples described here.
In all the embodiments of the invention described above and in the figures, the cooling medium tank can be set up as a horizontal tank or a vertical tank. Furthermore, the cooling medium tank 104 can be a conventional tank or a double walled vacuum-insulated tank which is normally used for storing cryogen/low temperature liquids and liquid gases.
Furthermore, the cooling medium tank 104 can be placed in the vicinity of the cooling system 100 and the heat exchanger system 110 and can be insulated to minimise evaporation as a consequence of heat transfer from the surroundings. In an alternative embodiment the cooling medium tank 104 can be placed together with the heat exchanger system 110 inside a closed and limited volume which is filled with insulation material to limit heat transfer from the surroundings. The insulated volume is often shaped as a box and is normally described as a “cold box”. The insulating material can be conventional insulation or granular insulating material which is filled into the box, such as perlite.
In an alternative embodiment the cooling medium tank 104 can also be used as cooling medium storage, for example, where the cooling medium is nitrogen, and such that the cooling medium tank can supply other parts of the processing installation with liquid or gaseous nitrogen when required. | A method and associated system for regulation of the cooling capacity of a cooling system that uses a gas expansion cooling circuit where the cooling principle is expansion of one or more gaseous cooling medium streams from a higher pressure to a lower pressure are described, characterised by the following steps: —reducing the amount of cooling medium which is circulated in the cooling circuit ( 100 ) temporarily in that a fraction of gaseous cooling medium is pre-cooled at a higher pressure and is extracted from the cooling circuit ( 100 ), —expanding the fraction of cooled gaseous cooling medium across an expansion device ( 102 ) to a lower pressure so that at least one part of liquid cooling medium separates, —separating the liquid from the non-condensed gas for temporary storage in a storage unit ( 104 ) so that the liquid is temporarily not circulated in the otherwise closed cooling circuit ( 100 ), —thereafter to return temporarily stored gaseous cooling medium from the storage unit ( 104 ) to the cooling circuit ( 100 ) according to need, and—returning non-condensed gas and evaporated cooling medium from the storage unit ( 104 ) to a suitable location in the cooling circuit ( 100 ). A system to reduce the cooling capacity of a cooling installation based on gas expansion cooling, is also described. | 5 |
FIELD OF THE INVENTION
The invention relates to a device for controlling the looper thread of a double chainstitch sewing machine, whose stitch length can be adjusted, with a thread guiding system including a thread delivery, a looper which can be oscillatingly driven in a sewing direction and a looper thread spreader which can be oscillatingly driven perpendicular to the sewing direction by means of a link mechanism.
BACKGROUND OF THE INVENTION
Generally, such devices on double chainstitch sewing machines serve the purpose of controlling the feed and removal of the looper thread to the looper during formation of the stitch. The spreader has the task of diverting to the side or pulling out the thread which protrudes out of the looper point and runs upwards to the stitch hole so that the descending point of the needle can move past between said thread and the looper. At this moment the looper thread should be slightly tensioned so that the so-called insertion movement, i.e. the insertion of the point of the needle into the thread triangle, two sides of which are formed by the needle thread and the other side by the looper thread, is accurately achieved.
Machines of this type are often equipped with a feeding device for the material to be sewn, the transport taking place at the same time as the needle penetrates the material. Such feeding devices are, for example, described in the German Offenlegungsschrift No. P34 11 217.0 corresponding to U.S. patent application Ser. No. 06/702,038. With such so-called needle-transport sewing machines the needle adopts different positions for different stitch lengths when it enters the thread triangle formed with the aid of the spreader, i.e. during the insertion movement, such a measure reducing the insertion accuracy especially with larger stitch lengths of 6 and more millimetres. After the insertion operation the spreader must not hinder the looper thread in any way when the latter is withdrawn from the spreader through the looper movement.
The procedure described above results in certain demands being placed on the sequence of movements of the spreader while it is acting on the looper thread. The remaining sequence of movements of the spreader, which lies inactive immediately adjacent to the looper, must be designed in such a way that a collision with the looper is absolutely precluded.
Furthermore, it is also desirable for the short-time action of the spreader on the under thread to be achieved by a spreader movement which exhibits a small amplitude and which thus permits another looper to be arranged at the smallest possible distance from the first looper so that parallel stitches can also be made.
A device of the generic type is known from a publication of Pfaff, Kaiserslautern, Federal Republic of Germany, "PFAFF adjusting instructions Pfaff 5642, No. 296-12-13 924". According to this publication the spreader is driven by a link mechanism which only satisfies the requirements placed on the movements of the spreader to a limited extent. In order to produce stitches with a maximum stitch length of 6 mm, spreaders whose points are bent are provided. These measures have an influence on the release of the looper thread and serve to compensate for inadequacies in the sequence of movements of the spreader. In addition to these spreaders, which are to be adjusted with great care, this device is also designed to control the looper thread with thread eyes in the thread delivery zone, said thread eyes adopting different positions in relation to each other depending on the set stitch length. These thread eyes can be adjusted for work with threads of different elasticity. The device is not suitable for influencing stitch formation to such an extent as to achieve an accurate stitch formation and good stitch tightening for stitch lengths which are considerably longer than 6 mm as well.
SUMMARY OF THE INVENTION
An object of the invention is to provide a device for controlling the looper thread of a double chainstitch sewing machine which has a simple design, is easy to handle and fulfils the afore-mentioned sewing requirements.
This object is solved according to the invention by designing the link mechanism as a six-link mechanism with three bearings said link mechanism consisting of a basic four-bar linkage and a secondary two-link group whereby two links are guided during a movement of the spreader in an extreme position in which it does not spread the looper thread.
The result of this measure is that the spreader is imparted a movement in which the spreading procedure takes place in a relatively short time. The spreader moves relatively quickly during the spreading, considerably decelerated during an inactive phase and almost at a standstill in its extreme position. The device according to the invention permits the use of spreaders with a simple design and dispenses with the need for displacement of the thread-guiding elements despite larger stitch lengths. When the links of the link mechanism are in the extreme position, this can either be a stretched or a covering position.
Furthermore, through the invention a connection of the spreader with the link mechanism exhibiting very little play is achieved. The invention permits the use of link elements which can be manufactured very accurately and cheaply. The design of the thread delivery disc as an axial groove brings the advantage of a space-saving design.
Further advantages and features of the invention will become apparent from the following description of a preferred embodiment and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a double chainstitch sewing machine;
FIG. 2 is a perspective view according to the arrow II in FIG. 1, showing essential components of the device according to the invention;
FIG. 3 is a diagram showing the sequence of motion of the spreader dependent on the angle of rotation of the drive;
FIG. 4 is a schematic perspective view according to the arrow IV in FIG. 1, showing the stitch forming procedure of a double chainstitch seam and
FIG. 5 is a schematic representation of the device according to the invention illustrated as a kinematic linkage.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings a sewing machine 1 is illustrated provided with a base plate 2, to one end of which is secured an upwardly extending standard 3. The standard 3 is formed with arm 4 extending parallelly with respect to the base plate 2 and terminating in a head 5. In the arm 4 an arm shaft 6 is pivoted one end of which projects through the standard 3 for receiving a handwheel 7 with a belt pulley 8 fastened to the latter. The belt pulley 8 is connected via a belt 9 to the drive of the sewing machine 1. The other end (not illustrated) of the arm shaft 6 terminates in the head 5 and is provided in the usual manner with a not shown crank for reciprocatingly driving a needle bar 10 and a thread take-up lever 11 via not shown elements. The needle bar 10 is displaceably received in a not shown needle bar jogging frame, which is oscillatingly driven by not shown elements in and oppositely to the sewing resp. feeding direction V. The lower end of the needle bar 10 is provided with a needle 12.
The arm shaft 6 is pivotally connected via a timing belt drive 13 (gear ratio 1:1) to a shaft 14, which is pivoted in the base plate 2. Inside of the standard 3 and the base plate 2 a not shown feeding device is provided, which, in the area of the needle 12, is drivingly connected to a feed dog 15. Such a feeding device is for instance described in German Offenlegungsschrift No. P 34 11 217.0. According to FIG. 1 the front surface of the standard 3 is formed with an opening 16, through which projects an adjusting lever 17 for altering the feeding increment of the feed dog 15. Adjustment of the adjusting lever 17 is readable from a scale 18.
At the front surface of the standard 3 a thread tensioner 19 for a needle thread 20 and a thread tensioner 21 for a looper thread 22 are provided. The needle thread 20 and the looper thread 22 each are supplied to the sewing machine 1 by a thread spool. After passing the thread tensioner 19, the needle thread 20 is led via a thread guide 23 located at the front surface of the arm 4, to the thread take-up lever 11 and then to the needle 12. after passing the thread tensioner 21, the looper thread 22 passes a thread guide canal 24 located at the front surface of the standard 3 and terminating shortly before reaching the base plate 2. In this area the base plate 2 is formed with a not shown opening for the passage of the looper thread 22 until reaching a thread eye 25. By the aid of the thread eye 25 the looper thread 22 is guided from its vertically extending direction into a horizontally extending direction and then is received by a thread eye 26. The thread eye 26 is part of an S-shaped thread guide 27 which, in addition to the thread eye 26 is provided with an intermediate thread eye 28 and a further thread eye 29.
From the thread eye 29 the looper thread 22 extends through a further eye 30 formed at the base plate 2, and finally to a double chainstitch looper 31. According to FIG. 4, the looper 31 is formed with a looper blade 32 extending oppositely to the feeding direction V. The free end of the looper blade 32 forms a looper point 33. Furthermore, the looper blade 32 is provided with a not shown U-shaped groove for guiding the looper thread 22 until leaving a bore 34 in the area of the looper point 33.
The looper 31 is connected via a carrier 35 to a shaft 36, which extends parallelly with respect to the shaft 14 and is pivoted in the base plate 2. Within the base plate 2 a not shown gear is provided for oscillatingly driving the looper 31. This gear is drivingly connected to the shaft 14.
According to FIG. 2 a connecting rod 39 is displaceably received in bearings 37, 38 situated in the base plate 2. The connecting rod 39 extends parallelly with respect to the shafts 36, 14. Just as the shaft 36, the connecting rod 39 projects from the central area of the base plate 2 through a wall 40 into the working area of the needle 12. The connecting rod 39 is formed with an off-set end 41, to which is secured a lever 42. The lever 42 extends in feeding direction V and is tilted slightly downwards with respect to the horizontal line. From the free end of the lever 42 projects a spreader 43, which is made from elastic wire and terminates in a tip 44. The spreader 43 extends substantially linearly above the looper 31 and its tip 44 terminates in the area of the needle 12 as viewed in feeding direction V.
In FIG. 2 a part of the shaft 14 is illustrated, which is supported in a bearing 45 of the base plate 2 and is provided with a driving spiral gear 46. The spiral gear 46 meshes with a driven spiral gear 47, which is secured to a cross shaft 48 extending rectangularly with respect to and below the shaft 14. The two spiral gears 46, 47 are formed so as to have a gear ratio of 1:1.
The cross shaft 48 is pivoted in a bearing 49 connected to the bearing 38, and a bearing 50 of the base plate 2. To the end 51 of the cross shaft 48 turned away from the spiral gear 47 a hub 52 of a thread delivery disc 53 is fastened. The thread delivery disc 53 is provided with a coaxial casing 54 the rounded-off front surface of which is profiled in longitudinal direction of the cross shaft 48 so as to form a cam surface 55. The casing 54 projects into the U-shaped area of the thread guide 27 provided with the thread eyes 26, 28. The guiding elements of the looper thread 22 comprising the thread tensioner 21, the thread guiding canal 24, the thread eye 25, the thread guide 27 with the thread eyes 26, 28, 29, the eye 30 and the thread delivery disc profiled with the cam surface 55, are denoted as thread guiding system 56.
According to FIG. 2 the cross shaft 48 is provided between the bearings 49, 50 with an eccentric 57, embraced by a collar of a tie rod 58. A pivot pin 59 is pressed into the free end of the tie rod 58 for rotatably receiving a lever 60, which form a joint 61. The lever 60 supports rotatably via a bearing 62 on a bolt 63. The bolt 63 is secured in a bearing 64 of the base plate 2 . The lever 60 extends transversely with respect to the cross shaft 48, i.e. the bolt 63 extends parallelly with respect to the cross shaft 48. Adjacent and in parallel with respect to the joint 61 of the lever 60 is provided a joint 65 for rotatably receiving a pivot pin 66. The assembly of elements comprising the bearings 50, 64, the bolt 63, the eccentric 57, the tie rod 58 with its pivot pin 59, and the lever 60 with its joint 61 and the bearing 62, forms a basic four-bar linkage 67, at which the lever 60 in conjunction with its bearing 62 and its joints 61, 65 forms an off-drive bar 68 in the kind of a triangular lever.
The pivot pin is fixedly connected to one end of a lever 69, the other end of which rotatably receives a bolt 70. The bolt 70 is a part of a connecting piece 71 fixedly connected to the connecting rod 39. As viewed in the sense of gear technology, supporting of the connecting rod 39 in the bearings 37, 38 creates an arrangement, which has the function of an endless lever pivoted in the base plate 2. Insofar, this imaginary lever formed by the bearings 37, 38 and the connecting rod 39 with the connecting piece 71 and the bolt 70, forms in conjunction with the lever 69 a two-link group 72. All elements of the basic four-bar linkage 67 and the two-link group 72 coupled thereto, form a six-bar linkage mechanism 73. At this, the two-link group 72 and the basic four-bar linkage 67 are arranged so that the lever 69 and the lever 60 together with its bearing 62 and the joint 65 are moved by the eccentric 57 into an almost stretched position when the spreader 43, as viewed in feeding direction V, takes in its left extreme position.
In FIG. 5, in principle, the construction of the gear according to FIG. 2 is illustrated as a kinematic linkage, at which the corresponding elements are denoted with the same reference numbers, however, with an "a" added. Moreover, as obvious from FIG. 5, the connecting rod 39a is hingedly connected via the lever 69a to the off-drive bar 67a. Thus, the movement of the connecting rod 39a is derived from the link 65a, which is moved on a circular arc segment.
Operation of the device for controlling the looper thread is as follows:
As a result of the drive of the arm shaft 6 the needle bar 10 including the needle 12 and the thread take-up lever 11 moves up and down. The shaft 14 moves through the same angle via the timing-belt drive 13. In accordance with the setting of the adjusting lever 17 the rotating movement of the shaft 14 of the feeding device imparts a rectangular movement to the feed dog 15. The latter movement, in conjunction with a standard hold down which is not illustrated causes the material N to be sewn to be advanced in a sewing feeding direction V.
During these movements an oscillating movement in and against the feeding direction V is also superimposed on the needle bar 10 moving up and down in such a way that the material to be sewn N is always advanced when the needle 12 has penetrated the material to be sewn N. The needle 12 enters the stitch hole provided in the feed dog 15. The above described interaction of the needle 12 and the feed dog 15 during the sewing operation is generally known from so-called needle-transport sewing machines.
Through the rotating movement of the shaft 14 the cross shaft 48 acting as a drive shaft for the eccentric 57 is driven in a rotating movement via the spiral gears 46, 47 whereby the speed of the cross shaft 48 corresponds to the speed of the arm shaft 6 owing to the 1:1 ratio of the spiral gears 46, 47 and the timing belt drive 13. Oscillating movements are transferred from the eccentric 57 driven by the cross shaft 48 to the off-drive bar 68 via the tie rod 58 and the pivot pin 59. During this process the lever 60 describes an oscillating motion which is then transferred via the pivot pin 66 to the lever 69 which in turn moves the connecting rod 39 to and fro perpendicular to the feed direction V via the connecting piece 71. As a result of this to-and-fro movement of the connecting rod 39 the spreader 43 also describes an oscillating motion perpendicular to the sewing or feeding direction V, said motion having the same frequency as the movements of the looper 31, the needle bar 10 with needle 12, the thread take-up lever 11 and the feed dog 15.
As the cross shaft 48 rotates, the thread delivery disc 53 also rotates whereby the groove 55 of the casing 54 acts on the looper thread 22 led between the thread eyes 26, 28 and lying in contact with the groove 55. In doing so, the thread delivery disc 53 causes another looper thread 22 to be pulled off the thread bobbin or the looper thread 22 to remain unaffected or the looper thread to be released or the latter to be withdrawn from the looper 31.
In FIG. 3 the movement A of the spreader 43 is represented by the curve 74 in relation to the angle of rotation T of the shaft 14 or the cross shaft 48. As can be seen from the path of the curve 74, the oscillating movement of the spreader 43 commences in said spreader's extreme position A0, in which the linkage mechanism 73 adopts its stretched position, where the spreader 43 thus adopts a prolonged standstill position. At this moment the cross shaft 48 adopts the angle of rotation T0. After an angle of rotation T1 of approximately 90° has been described, whereby the spreader 43 is only minimally displaced from its extreme position A0, the looper thread 22 is touched by the spreader 43 at a point in time when the latter has adopted a position according to A1. In the further course of the sequence the spreader 43 follows the path of the curve 74 until the moment of the so-called insertion operation, i.e. the penetration of the descending needle 12 into the triangle of thread formed on two sides by the needle thread 20 and on the other side by the looper thread 22. This moment is defined so that the point of the needle 12 is positioned on a lever with the top of the looper blade 32 as illustrated in FIG. 4. According to the path of the curve 74 the cross shaft 48 has now adopted an angle T2 whereby T2 is about 180° corresponding to the reversing point of the spreader 43.
FIG. 3 shows that the spreader 43 acts for a relatively short period on the looper thread 22. The spreader 43 describes 70-80% of its swing-out movement through an angle of rotation of about only 90°. In the further path of the curve the spreader 43 executes an inactive movement whereby said spreader returns at a decelerated rate without any contact with the looper thread 22 in accordance with the remaining path of the curve 74 to its extreme position A0' corresponding to the angle of rotation T0' of the cross shaft 48. Owing to the movement of the spreader 43 in accordance with the path of the curve 74 spreader movements which are favourable to the sewing operation are achieved over a relatively wide range of stitch lengths. The decelerated and accelerated movement sequences of the spreader 43 on the one hand lead to a space-saving oscillating amplitude and on the other hand provide the possibility of keeping the looper thread 22 tensioned through a corresponding design of the thread delivery disc 53 via the angle of rotation or the time period T1 to T2 during which the spreader 43 acts. Thus the insertion accuracy is further increased. | A device for controlling the looper thread of a double chainstitch sewing machine has a looper which can be oscillatingly driven in the sewing direction. A link mechanism is provided to drive the spreader, said link mechanism being designed as a six-bar linkage mechanism with a four-bar linkage and a secondary two-link group. The basic linkage and the two-link group are arranged in such a manner that two links are guided during a movement of the spreader in an extreme position in which it does not spread the looper thread. Thus a spreader movement is produced which is particularly adapted to the sewing process. | 3 |
FIELD OF THE INVENTION
The present invention relates generally to manufacturing, and more particularly to a system and method for monitoring gas pipes in a manufacturing environment.
BACKGROUND
Semiconductor manufacturing requires a variety of process tools that utilize pressurized gas and/or vacuum to operate. Such tools include deposition tools and polishing tools, for example. In some cases, effluent adhering to pipe sidewalls gradually reduces the inside diameter of a pipe over time. This in turn makes the internal pressure higher, which can cause seal failures at pipe fittings. Often, an O-ring seal is employed in a pipe fitting which connects two pipe segments together. The increased pressure can cause O-rings to burst or leak. In a manufacturing environment with many process tools utilizing a variety of pressurized gas and vacuum sources, identifying the location of such a leak can be challenging. Furthermore, in some cases, the gases in use are highly toxic to people, warranting a need to quickly identify and locate such leaks for the safety of personnel on site. Ultrasonic leak detectors are not effective on active exhaust leaks as they can falsely identify flow in the pipe as a leak. Prior art exhaust gas detectors are large and bulky and provide only coarse information regarding the location of a leak. Therefore, it is desirable to have an improved pipe monitoring system and method for detecting and locating pipe leaks.
SUMMARY OF THE INVENTION
In one embodiment of the present invention, a pipe clamp is provided. The pipe clamp comprises, a housing, the housing configured and disposed to surround a pipe fitting, an input port disposed in the housing, an output port disposed in the housing, and a sensor port disposed in the housing, wherein the housing and the pipe fitting form a containment chamber.
In another embodiment of the present invention, a system for containing and monitoring gas pipe leakage is provided. The system comprises a first pipe clamp and a second pipe clamp. Each pipe clamp comprises a housing which is configured and disposed to surround a pipe fitting, an input port disposed in the housing, an output port disposed in the housing, and a sensor port disposed in the housing. The housing and the pipe fitting form a containment chamber. The first pipe clamp and second pipe clamp are connected in series with an exhaust line, such that the exhaust line is connected to the input port of the first pipe clamp, and the output port of the first pipe clamp is connected to the input port of the second pipe clamp. A second pipe clamp pressure sensor is configured and disposed to monitor pressure in the containment chamber of the second pipe clamp.
In another embodiment of the present invention, a method for containing and monitoring gas pipe leakage is provided. The method comprises covering a pipe fitting of a monitored pipe with a pipe clamp, connecting a pressure sensor to a sensor port on the pipe clamp, monitoring pressure inside the pipe clamp via the pressure sensor, and indicating a leak in the monitored pipe in response to detecting a pressure outside of a first predetermined pressure range.
BRIEF DESCRIPTION OF THE DRAWINGS
The structure, operation, and advantages of the present invention will become further apparent upon consideration of the following description taken in conjunction with the accompanying figures (FIGs.). The figures are intended to be illustrative, not limiting.
Certain elements in some of the figures may be omitted, or illustrated not-to-scale, for illustrative clarity. The cross-sectional views may be in the form of “slices”, or “near-sighted” cross-sectional views, omitting certain background lines which would otherwise be visible in a “true” cross-sectional view, for illustrative clarity.
FIG. 1 is a perspective exploded view of a pipe clamp in accordance with an embodiment of the present invention.
FIG. 2 is a perspective exploded view of a pipe clamp in accordance with an embodiment of the present invention illustrating a pipe fitting within the clamp.
FIG. 3 is a perspective view of a pipe clamp in accordance with an embodiment of the present invention illustrating the clamp in a sealed position.
FIG. 4 is a side view of a pipe clamp in accordance with an embodiment of the present invention illustrating the containment chamber of the pipe clamp.
FIG. 5 is a side view of a pipe clamp in accordance with an embodiment of the present invention illustrating exhaust air flow through the pipe clamp.
FIG. 6 is a side view of a pipe clamp in accordance with an embodiment of the present invention illustrating a leak in a monitored pipe.
FIG. 7 is a block diagram of a system in accordance with an embodiment of the present invention.
FIG. 8 is a block diagram of a system in accordance with an alternative embodiment of the present invention.
FIG. 9 is a flowchart indicating process steps for a method in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1 is a perspective exploded view of a pipe clamp 100 in accordance with an embodiment of the present invention. Pipe clamp 100 is comprised of a housing that is comprised of lower housing 102 and upper housing 104 . Lower housing 102 comprises input port 106 . Upper housing 104 comprises output port 108 and sensor port 114 . Upper housing 104 has semicircle interior portion 119 and lower housing 102 has corresponding semicircle interior portion 117 . Lower housing 102 has gasket 116 affixed to it along the mating edge where it meets upper housing 104 . Similarly, upper housing 104 has gasket 118 affixed to it along the mating edge where it meets lower housing 102 . In one embodiment, the gaskets 116 and 118 are comprised of rubber. The lower housing 102 and upper housing 104 may be comprised of polypropylene. In other embodiments, the lower housing 102 and upper housing 104 may be comprised of another type of plastic material. In other embodiments, the lower housing 102 and upper housing 104 may be comprised of a metal, such as stainless steal or aluminum. The upper housing 104 is fastened to lower housing 102 via fasteners 110 and 112 . The lower housing 102 has a well 130 within it. A similar well is in the upper housing (not shown). When the lower housing 102 is fastened to upper housing 104 , the wells unite to form a containment cavity and the semicircle interior portions 117 and 119 unite to surround, and fit around a pipe fitting. For simplicity in manufacturing the pipe clamp, lower housing 102 and upper housing 104 may be identical parts, although embodiments of the invention may utilize non-identical parts.
FIG. 2 is a perspective exploded view of pipe clamp 100 illustrating a pipe fitting within the clamp. In this view, a first pipe segment 220 is affixed to a second pipe segment 222 via O-ring fitting 224 . Upper housing 104 and lower housing 102 surround the O-ring fitting 224 to encapsulate it within the containment cavity.
FIG. 3 is a perspective view of pipe clamp 100 illustrating the clamp in a sealed position. In this view, the upper housing 104 is fastened to lower housing 102 via fasteners 110 and 112 (see FIG. 2 ).
FIG. 4 is a side view of pipe clamp 100 illustrating the containment chamber 430 of the pipe clamp. The containment chamber 430 encapsulates O-ring fitting 224 . Hence the housing (comprised of lower housing 102 and upper housing 104 ) and the fitting 224 form containment chamber 430 . Input port 106 vents into the containment chamber 430 , and the containment chamber 430 vents to output port 108 and sensor port 114 . Sensor port 114 may be capped if a sensor is not in use.
FIG. 5 is a side view of pipe clamp 100 illustrating exhaust air flow through the pipe clamp. The exhaust airflow, indicated by the arrows with reference “E,” enters pipe clamp 100 via input port 106 and exits via output port 108 . A pressure sensor 532 is connected to a sensor conduit 534 which is connected to the sensor port 114 . Under steady-state conditions, where the O-ring fitting 224 is intact, a relatively constant pressure level is detected by pressure sensor 532 . In one embodiment, pressure sensor 532 is a differential pressure sensor. Pressure sensor 532 may also comprise an interface for determining the pressure, such as an analog signal, digital signal, and/or contact closure. The contact closure may be normally opened, and then close when the detected pressure is outside of a predetermined pressure range.
FIG. 6 is a side view of a pipe clamp in accordance with an embodiment of the present invention illustrating a leak in a monitored pipe. In this case, the pressurized O-ring fitting 224 developed leak 636 . This causes an increased pressure reading by sensor 532 which is then used to indicate a leak in fitting 224 . The gas from leak 636 is vented out of the containment chamber 430 via output port 108 , and can be vented to a safe location (e.g. into a scrubber or other environmentally safe location). Hence, the leak is both detected, and safely mitigated. While this example described a leak that causes an increase in the pressure detected by sensor 532 , it is also possible to utilize embodiments of the present invention to detect vacuum leaks. In the case of a vacuum leak, the pressure detected by sensor 532 drops upon occurrence of a vacuum leak. The pressure drop can then be used to indicate a vacuum leak has occurred. Hence, embodiments of the present invention can identify a leak type as one of outward leak (pressure increase), and vacuum leak (pressure drop).
FIG. 7 is a block diagram of a system 700 in accordance with an embodiment of the present invention. A first pipe clamp 100 A is connected in series to a second pipe clamp 100 B. The output 108 A of pipe clamp 100 A is connected to the input 106 B of pipe clamp 100 B. The pipe clamps 100 A and 100 B are in line with an exhaust line 744 that is connected to an exhaust source 740 (e.g. air pump). A sensor 532 is connected to second pipe clamp 100 B, while no sensor is connected to pipe clamp 100 A. The sensor port 114 A for pipe clamp 100 A is capped. The output of sensor 532 is connected to machine controller 742 . Machine controller 742 may be a computer comprising a non-transitory computer memory 743 that contains instructions which, when executed by processor 745 onboard machine controller 742 , activate a shutdown (or stop) sequence for process tools associated with the pipe clamp. Note, for the purposes of this disclosure, “shutdown” means putting the process tool in a stopped state, which may be a full shutdown, or other stopped, “offline” or “standby” state. The machine controller may send messages to each process tool to initiate its shutdown or stoppage. The machine controller may communicate to each process tool via a communications protocol, such as SECS/GEM, or other suitable protocol. The machine controller 742 may also indicate the leak to an operator. The indication (operator alert) may be in the form of an audible alert and/or visual alert in the production facility, such as a blinking light and buzzer. The machine controller may also send an e-mail and/or SMS (text) message to one or more addresses.
In this example, two process tools ( 746 , 748 ) are controlled by machine controller 742 .
Both process tools utilize a common compressed gas line 750 (for the sake of illustrative simplicity, not all parts of compressed gas line 750 are shown). Gas line 750 has seals that are covered by pipe clamp 100 A and 100 B. Gas line 750 is referred to as a “monitored pipe” because the integrity of its fittings is monitored by pipe clamps 100 A and 100 B. The pipe clamps cover the fittings of the monitored pipe. If the fitting (or seal) covered by pipe clamp 100 A or 100 B leaks, a pressure change is detected at sensor 532 . It is then known the fitting at one or more of the pipe clamps has failed. Hence, the leak can be narrowed down to a subset of possible fittings within a production line. Note that while two pipe clamps are shown in this example, it is possible to use more than two pipe clamps. For example, eight pipe clamps may be used, where the sensor is connected to the last pipe clamp in the series, and the other seven pipe clamps have a capped sensor port. In this case, when the sensor registers a significant pressure change, it can be inferred that one of the eight fittings being monitored has failed.
FIG. 8 is a block diagram of a system 800 in accordance with an alternative embodiment of the present invention. In this embodiment, each pipe clamp has a sensor. Hence, pipe clamp 100 B has sensor 532 attached to it, and pipe clamp 100 A has sensor 532 A attached to it. In this case, it may be possible to determine which seal failed by detecting which sensor ( 532 A or 532 ) measured a pressure difference first. For example, if the fitting monitored by pipe clamp 100 A fails, then sensor 532 A registers a pressure difference before pressure sensor 532 . The time delta between when sensor 532 A registers a pressure difference and when sensor 532 registers a pressure difference, depends in part, on the length of the gas line 750 between the two pipe clamps. In this way, by providing a sensor for each pipe clamp in the series, it provides for identifying which seal within the series has failed. It also provides a level of redundancy, such that if a particular sensor fails, functioning sensors on the other pipe clamps in series still register the pressure differential and can indicate a leak has occurred at a fitting along the monitored pipe. Note that while two pipe clamps are shown in this example, it is possible to use more than two pipe clamps. For example, eight pipe clamps may be used, where a sensor is connected to each of the eight pipe clamps in the series.
FIG. 9 is a flowchart 900 indicating process steps for a method in accordance with an embodiment of the present invention. In this embodiment, a first pressure range and second pressure range may be established. The second pressure range is greater than, and encompasses the first pressure range. For example, the first pressure range may be −30 psi to 30 psi, and the second pressure range may be from −50 psi to 50 psi. Note that, depending on the application (e.g. pressurized gas, or vacuum) the monitored pressures may typically be either positive or negative. In process step 960 , the pressure in a pipe clamp (such as shown in FIG. 5 ) that surrounds a monitored pipe fitting is continuously monitored. In process step 962 , a check is made to determine if a first pressure range is exceeded. If not, then monitoring of pressure continues. If yes, then the leak is classified at a first severity level, and an alert is issued in process step 964 . This may be performed by the machine controller ( 742 of FIG. 7 ). The alert may comprise an audio and/or visual alert near the location of the leak, or sending of e-mails, text messages, or automated phone calls to convey the alert. Alternatively, a combination of techniques may be used. In process step 966 a check is made to determine if a second pressure range is exceeded. If not, then monitoring of pressure continues. If yes, then the leak is classified at a second severity level, and the machine controller ( 742 of FIG. 7 ) activates a shutdown in process step 968 to shut down equipment that is associated with the leak. For example, if five process tools utilized a compressed nitrogen line, then all five tools may be shut down upon detection of a leak in the nitrogen line. The actions to take upon detection of a leak depend on the processes, and the type of gas. In some cases, the process tools can safely complete the current production cycle with the leak. In this case, the leak may be repaired during the next maintenance cycle. In cases where the safety of workers are at risk (e.g. the leaking gas is highly toxic), or where the product yield will significantly be impacted due to the leak (e.g. if a precursor gas is not flowing at the proper rate due to the leak), then the process tools may be shut down to address the leak immediately. Some embodiments may only issue alerts, or only activate a shutdown. Other embodiments may issue an alert, or both issue an alert and activate a shutdown.
As can now be appreciated, embodiments of the present invention provide an effective way to detect and contain gas leaks that can form in pipe fittings having seals such as O-rings. Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, certain 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 components (assemblies, devices, circuits, etc.) the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiments of the invention. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several embodiments, such feature may be combined with one or more features of the other embodiments as may be desired and advantageous for any given or particular application. | A system and method for detecting leaks in pressurized or vacuum pipes is disclosed. A pipe clamp comprises a housing that surrounds a pipe fitting. A containment chamber within the pipe clamp prevents leaked gas from escaping into the environment. The pipe clamp is installed in series with an exhaust line to remove the leaked gas from the containment chamber. A sensor may be configured and disposed to detect a change in pressure in the containment chamber to indicate the occurrence of a leak. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a four-cycle engine for a marine propulsion device and more particularly to an improved method for lubricating the camshaft of an internal combustion engine.
As is well known, most internal combustion engines operating on four-stroke cycle principles are provided with a pressure lubricating system for lubricating the components of the engine. Quite frequently, as with the case of an overhead camshaft engine, the camshaft is located remotely from the oil pump. As a result, the critical bearing surfaces of the camshaft such as the cam lobes and the valves or rocker arms which they engage do not receive lubricant immediately upon starting of the engine. Frequently, the engine may run for some brief period of time before lubricant reaches these critical components.
When the engine is operated in conjunction with an outboard motor, it is the normal practice to dispose the engine so that its output shaft rotates about a vertically extending axis. When this is done, the camshaft is also supported for rotation about a vertically extending axis and this further complicates the problem in lubricating the camshaft and specifically the cam lobes and the elements which they operate.
It is, therefore, a principal object of this invention to provide an improved lubricating system for an internal combustion engine.
It is another object of this invention to provide a lubricating system for an internal combustion engine that insures lubrication of the camshaft lobes and related mechanism even during starting.
SUMMARY OF THE INVENTION
This invention is adapted to be embodied in a lubricating system for an internal combustion engine including a camshaft journaled by the engine. The engine is provided with a lubricating system including a lubricant pump for delivering lubricant under pressure to at least some of the components of the engine. In accordance with this invention, porous means adapted to engage a surface of the camshaft to be lubricated are provided with means for delivering lubricant to them from the lubricant pump so that the cam surface will be lubricated at all times when the engine is turning.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of an outboard motor constructed in accordance with an embodiment of the invention.
FIG. 2 is an enlarged cross-sectional view of the engine of the outboard motor taken through the axis of its cylinder bores.
FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG. 2.
FIG. 4 is an enlarged view showing another embodiment of the invention.
FIG. 5 is an enlarged view, in part similar to FIG. 4, showing a still further embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, an outboard motor constructed in accordance with an embodiment of the invention is identified generally by the reference numeral 11. The outboard motor 11 includes a power head consisting of an internal combustion engine, indicated generally by the reference numeral 12, and a surrounding protective cowling, which is shown in phantom in FIG. 1 and which is identified by the reference numeral 13. A drive shaft housing 14 depends from the power head and contains a drive shaft 15 that is driven by the engine output shaft in a manner to be described. A lower unit 16 is positioned at the lower end of the drive shaft housing 14 and contains a forward, neutral, reverse transmission 17 which is driven by the drive shaft 15 and, in turn, is adapted to drive a propeller 18 in a well known manner.
The drive shaft housing 14 is connected to a swivel bracket 19 by means including a steering shaft 21 for steering of the motor 11 about a vertically extending axis relative to the swivel bracket 19. The swivel bracket 19 is, in turn, affixed to a clamping bracket 22 by means of a tilt pin 23 so that the motor 11 may be tilted about a horizontally extending tilt axis defined by the pin 23. The clamping bracket 22 carries a clamp 24 so that the motor 11 may be detachably affixed to a transom 25 of an associated watercraft.
Referring now additionally to the remaining figures, the engine 12 is of the two cylinder in-line type and operates on the four-stroke principle. The engine 12 is comprised of a cylinder block 26 in which a pair of horizontally extending vertically, spaced cylinder bores 27 are formed. Pistons 28 are supported for reciprocation within the cylinder bores and are connected by means of piston pins 30 to one end of connecting rods 29. The other ends of the connecting rods are journaled on a crankshaft, indicated generally by the reference numeral 31. The crankshaft 31 is supported for rotation within a crank chamber 32 in a suitable manner between the cylinder block 26 and a crankcase 33 that is affixed to the cylinder block 26. The crankshaft 31 is drivingly coupled to the drive shaft 15 in a suitable manner.
A cylinder head, indicated generally by the reference numeral 34, is affixed to the cylinder block 26 with a cylinder head gasket 35 being interposed therebetween for providing a seal between the two surfaces. The cylinder head 34 is provided with a pair of recesses 36, each of which cooperates with the cylinder bore 27 and piston 28 to form the respective combustion chamber.
An intake valve 37 is supported in the cylinder head 34 for each combustion chamber 36 (FIG. 3). The intake valves 37 control the flow of fuel/air mixture from an induction system including a cylinder head intake passage and associated carburetor (not shown) which may be of any conventional construction. In a similar manner, an exhaust valve 38 is supported for reciprocation within the cylinder head 34 for each of the combustion chambers 36 and controls the flow of exhaust gases from the chambers 36 to the atmosphere through a suitable exhaust system (not shown).
The intake and exhaust valves 37 and 38 are operated in a manner to be described by means of a camshaft 39 that is supported for rotation within the cylinder head 34 by a means also to be described. The camshaft 39 is contained within a cam chamber 41 of the cylinder head 34 which is closed by a cam cover plate 42. The cover plate 42 is affixed to the cylinder head 34 in any suitable manner.
The upper end of the camshaft 39 is exposed and carries a driven pulley or sprocket 43. A toothed belt 44 transfers drive from a driving sprocket 45 fixed to the exposed upper end of the crankshaft 31 to the driven sprocket 43 and camshaft 39.
Intake rocker arms 46 are journaled on an intake rocker arm shaft 47 carried by the cylinder head 34 and engage the tips of the stems of the intake valves 37 for operating the intake valves upon rotation of the camshaft 39. The camshaft 39 has, for this purpose, intake lobes 48 that engage the rocker arms 46 for operating them. In a similar manner, exhaust rockers 49 are carried on an exhause rocker shaft 51 which is, in turn, carried by the cylinder head 34. The exhaust rockers 49 engage the tips of the stems of the exhaust valves 38 so as to operate them. The exhaust rockers 49 are operated by exhaust lobes 52 of the camshaft 39. The intake and exhaust rockers 46 and 49 each have bearing surfaces 53 that are engaged with the respective cam lobes 48 and 52.
The engine 12 is provided with a lubricating system including a lubricant pump, indicated generally by the reference numeral 54. The lubricant pump 54 includes a main housing 55 that is received within an opening formed in the lower face of the cylinder head 34. The housing 55 is formed with an internal bore which serves the function of journaling the lower end of the camshaft 39 relative to the cylinder head 34. A pumping element 56 is contained within a pumping cavity 57 of the housing 55 and is driven from the camshaft 39 by means of a short drive shaft 58.
An oil pan or sump 59 is affixed to the underside of a spacer plate 60 that supports the engine 12 and which connects the power head to the drive shaft housing 14. An oil delivery tube 61 depends into the sump 59 and communicates with an inlet passage 62 formed in the cylinder block and an inlet passage 63 formed in the pump housing 55 for delivering lubricant to the pumping chamber 57.
Pressurized lubricant is delivered through a first cylinder block and cylinder head delivery passageway 65 for lubricating a lower main bearing journal portion 66 of the crankshaft 31. A suitable seal 67 is carried by the crankcase 33 and cylinder block 26 for sealing this journaled area. In addition, the crankshaft 31 is formed with a cross-drilled passage 68 that communicates with the pressure conduit 65 and which terminates in the journal portion of one of the crankshaft throws for lubricating a connecting rod main bearing portion 69 and its attached bearing cap 71.
A pressure delivery passage 72 extends from the outlet side of the pump 54 through the cylinder head 34 and intersects another cross-drilled passageway 78 of the cylinder head 34 and cylinder block 26. The passageway 78 extends to an upper main bearing 79 of the crankshaft 31 for lubricating this bearing. A seal 81 is carried by the cylinder block 26 and crankcase 33 for sealing this bearing. A cross-drilled passageway 82 extends through the crankshaft main bearing portion 78 into its throw for journaling the upper connecting rod main bearing 69 and bearing cap 71.
The upper end of the camshaft 39 is formed with a bearing portion 83 that is journaled in a bore 84 of the cylinder head 34. The upper passageway 78 terminates at this bearing surface for lubricating the camshaft bearing surface 83. A seal 85 is provided in the cylinder head 34 adjacent the outer side of the bearing surface 83.
With conventional prior art lubricating systems, lobe surfaces 86 of the intake cams 48 and lobe surfaces 87 of the exhaust cams 52 and the corresponding engaging surfaces 53 of the rocker arms 46 and 51 are lubricated in a pressure manner. With such an arrangement, however, lubricant does not reach these surfaces until a period of time after the engine has been running. Hence, during start up and initial running, these surfaces could be subject to wear due to lack of adequate lubrication. This problem is particularly acute when the engine is disposed with the axis of the camshaft 39 extending in a vertical direction, as is common practice with an outboard motor, as has been noted.
In accordance with this invention, an arrangement is provided whereby lubricant is always delivered to the surfaces 86 and 87, even when the engine is not running. For this purpose, the cylinder head 34 is provided with individual recesses adjacent the cam cavity 41 in which bodies of porous material 88, such as sponge rubber or the like, are pressed. The sponge rubber or porous material bodies 88 are disposed so that they will be constantly in engagement with the cam surfaces 86 and 87 and also so that they are disposed immediately beneath the camshaft bearing 83. Hence, lubricant will be delivered ownwardly from the bearing 83 onto the porous bodies 88 so that they will be saturated with oil. Thus, even when the engine is not running, the porous bodies 88 will be saturated with oil. Upon cranking for starting, therefore, the surfaces 86 and 87 and the rocker arm surfaces 53 will all receive lubricant immediately and regardless of whether or not pressurized oil is delivered. Hence, wear is substantially reduced.
A drain passage 89 is formed in the cylinder head lower surface 34 in communication with the lower portion of the cam cavity 41. The drain passage 89 mates with a corresponding drain area 91 formed in the lower face of the cylinder block 26 and is aligned with an oil return opening 92 in the spacer plate 60 that is disposed immediately above the oil reservoir 59 so that oil can be returned to this reservoir when it has circulated through the camshaft arrangement. In a similar manner, a drain opening 93 is formed in the lower face of the crankcase chamber 32 so as to permit oil from the crankcase to drain back into the reservoir 59.
FIG. 4 shows a slightly different embodiment of the invention. The embodiment of FIG. 4 employs a slightly different arrangement for mounting the porous sponge rubber members from the embodiment of FIGS. 1 through 3 and, for that reason, only this portion of the construction has been illustrated. The cylinder head 34 is provided with a ledge 101 on which a plurality of carrier elements 102 are secured by machine screws 103. The carrier elements 102 each have recesses that carry a porous sponge rubber bodies 104 that will contact the cam surfaces 86 and 87 in the same manner as the embodiment of FIGS. 1 through 3. In addition, the porous members 104 are disposed so that they will be positioned beneath the camshaft bearing 83 and will receive lubricant from it.
FIG. 5 shows a further modified embodiment of the invention. In the previously described embodiments, the sponge rubber bodies 88 and 104 were all held in a fixed position. This is acceptable since they can deflect to follow the cam lobe surfaces 86 and 87. However, in this embodiment, a leaf spring 121 is affixed to the cylinder head 34 by means of a machine screw 122. Each leaf spring carries a foam pad 123 formed from rubber or some other suitable porous material which engages the cam lobes 86 and 87. As the camshaft 39 rotates, the leaf spring 121 will deflect as shown in the solid line of this figure so that the foam member 123 will follow its profile and insure adequate lubrication.
It should be readily apparent from the foregoing description that a number of embodiments of the invention have been illustrated and described, each of which insures good lubrication for the camshaft surfaces immediately upon starting and even during cranking of the engine without dependence on its pressure lubrication system.
Although a number of embodiments have been illustrated and described, various other changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims. | Several embodiments of outboard motors incorporating improved arrangements for lubricating the cam lobes and associated components of the camshaft that is relatively independent of the pressure lubricating system of the engine. In each embodiment, a porous member is saturated with lubricant and engages the cam lobe surface so as to lubricate it even immediately upon starting. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] Priority is claimed to U.S. Provisional Patent Application Ser. No. 60/481,957, filed Jan. 27, 2004, the contents and program listing of which are incorporated herein by reference. This application is a continuation-in-part of U.S. patent application Ser. No. 10/997,121, filed Nov. 24, 2004, which has priority to Provisional Application Ser. No. 60/525,905, filed Nov. 26, 2003, the contents of both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a system and method of collecting, revising, organizing and storing data concerning an online community.
[0004] 2. Description of the Related Art
[0005] A widely used model for organizing and implementing purchases online is use of a shopping cart analog. Such electronic commerce typically involves users browsing web sites and, when they see items that they want to purchase, adding the items to the shopping cart (phase 1 of purchasing). When they have added all their items, users typically enter a check-out phase (phase 2 of purchasing) that allows the users to confirm the items in their shopping cart and specify or modify shipping and payment information. In another shopping model, online commerce websites have pre-stored purchase and delivery information for some users, and once the users have selected and approved items for purchase, the order is completed. A more recent phenomenon is the usage of online social networking systems that allow people to exist in communities and publish content to the web or associated content with themselves. There have also been approaches that allow groups to browse the web together and shop together by sharing reviews and other preferences. One way to accomplish this includes linking to content in known systems, such as a hyperlink to the associated content of friends, or a user could re-create the content and provide a message saying where the content originated, etc. One deficiency of the known methodology is that user input and linking is required, making it relatively difficult for a user to share and make available shopping or product information.
[0006] One known linking methodology applied to creative processes has been developed by Creative Commons (creativecommons.org), which provides licenses for creation of derivative works (new creative works based pre-existing works), which allows users to share their creativity. Although this promotes sharing in the creative process, it suffers the deficiency that it fails to provide a way of sharing in product or service shopping, or in sharing preferences pertaining to media such as music, video, shows, etc.
[0007] Accordingly, there exists a need for a system and method of sharing and passing on of content, such as art or music reviews, and product preferences, while giving credit to the original author and providing a reference to the original form created by the author.
[0008] A known means for content referencing has been through the use of external or internal hyperlinking. This method suffers a disadvantage of not allowing content to be present with the user or group who is advocating it, and requires clicking a link for access. Accordingly there also exists a need for an automated system of providing users with the ability to incorporate and reference other user or group content into their own content collections. There further is a need for a system providing improved access to incentives for content creators to allow their content to be collected in such a manner.
[0009] There also is a need for a system and method of collecting, sharing, and tracking user or group associated activity via a communications network that enables users to easily incorporate other users' content into their own content—whether related to products, services, reviews or any form of content a user may wish to associate with herself or himself.
SUMMARY OF THE INVENTION
[0010] The present invention alleviates to a great extent the disadvantages of known advertising and content evaluation systems by providing an automated mechanism where brand owners can tap into a network of individuals or groups who are willing to represent their brands via their identities as part of a community.
[0011] In some embodiments, the present invention involves using a tool referred to as a GRAB BAG to collect the content or associated content of individuals or groups and associate it with a particular user. In this embodiment, individuals or groups agree to allow such content to be collected in exchange for a service, as part of an online service, or for some reward, monetary or otherwise. Once grabbed, the content can be referenced from the grabbers' content or even purchased via traditional shopping cart functionality, which in one embodiment would have an associated reward for the owner of the original associated content. In one implementation, it also provides a way for the original content owner to track the dissemination of his/her material.
[0012] In one aspect of the invention, a framework of collecting and sharing images in an online gallery is provided. In this aspect, users optionally are connected via their real life relationships to one another. For example, a user may browse a friend's (such as for hypothetical example, Mike's) galleries. The user can add to his/her GRAB BAG all the images that Mike has in his gallery. The user can access another friend's (such as for hypothetical example, Melissa's) content and add an image of a mutual friend that the user finds in one of her galleries to the user's GRAB BAG. Once in the GRAB BAG, the user may convert the image to a gallery of his/her own (optionally referencing Melissa and Mike) for people who visit the user's galleries (which may be a different audience) to view. It should be noted that “friend” is used herein to mean any associated individual or group and does not require there to be a personal relationship outside the context of the referencing discussed herein. Alternatively, the user may wish to print these images in his/her GRAB BAG via a partnered picture printing service company. In either case, Mike and Melissa may receive a reward of some kind. In one example, the reward would be a percentage of the image printing profit or the advertisements that are associated with the pages when their pictures are present, although other forms of rewards also may be provided. Mike and Melissa could also take advantage of an interface that informed them about who had collected their content. One benefit to this method is that the content need not be duplicated. It can exist once in storage and be referenced by more than one individual. For example, if there is video that is being referenced on Jack's web page and on Jill's web page, but it is John's original content collected from John's page, the video need only be stored once, even if there are three distinct references to it.
[0013] In another embodiment, if Mike is part of a system that allows him to associate his online presence with an advertisement or brand and a user browses his content and views the brand that he/she is supporting, the user may add the brand to his/her GRAB BAG. This implicitly associates the user with the content, in this case a brand.
[0014] By providing such a framework, the current invention provides an incentive for users to share and create valuable content to such online communities, provides an storage efficient way for creating rich content collections for a multiplicity of users, and allows an easy mechanism for viewers to incorporate, find, manage, and bookmark content that they like. It also provides an efficient method for spreading content across networked individuals rapidly. This invention is particularly useful in conjunction with a system such as described in U.S. patent application Ser. No. 10/997,121, filed Nov. 24, 2004 and Provisional Application Ser. No. 60/525,905, which are incorporated herein by reference.
[0015] Further examples of advantages of the present invention include an easy to use interface and system whereby a user can quickly and efficiently collect and incorporate associated content that they view or browse into their own content displays; a content creator or associated content agent can determine which pieces of content can be collected via such a system, as well as monitor the usages of this content; and users can relatively easily collect content they are browsing for referenced inclusion in their content or for purchase.
[0016] In one aspect of the invention, a method of managing content is provided comprising receiving a request in a server system from a viewer to access content associated with a user or group of users, presenting the content to the viewer, receiving a content association request from the viewer relating to requested content, and adding the requested content to content associated with the viewer. The content association request can include a content identifier associated with the requested content, and the server can retrieve the content using the content identifier. The server can also perform a determination procedure to determine whether the viewer is authorized to collect the requested content. Furthermore, the server can determine the viewer's proposed use of the requested content and determine if the proposed use of the requested content complies with one or more previously specified use criteria for the requested content, such as specified by the user or author. The use criteria can be selected from a group consisting of creative common licenses, distribution, modification, and attribution. The content can includes digital content data that optionally includes product purchasing information. A reward can be provided to users whose content is retrieved or whose content leads to a purchase by other users or viewers. In a further aspect of the invention, the viewer is required to pay to retrieve content. In another aspect of the invention, the user can post comments on the content and contribute to the requested content.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These and other features of the invention, its nature, and various advantages will be appreciated from the accompanying drawings, and the following detailed description in which like reference numbers represent like parts throughout:
[0018] FIG. 1 is a block diagram of a method and system for collecting, sharing, and tracking content via a communications network, in accordance with a preferred embodiment of the present invention referred to as a GRAB BAG system;
[0019] FIG. 2 is a flow chart depicting the high level functionality of the GRAB BAG system via a communications network;
[0020] FIG. 3 is a flow chart showing the client-server functionality from when content is GRABBED to how it may be stored in the database;
[0021] FIG. 4 is a block diagram of a viewer client for the GRAB BAG system;
[0022] FIGS. 5 and 6 show a database schema for a preferred embodiment of the invention (as shown by metails.com and which the attached program listing interacts with);
[0023] FIG. 7 is an illustration of an example add to GRAB BAG client display; and,
[0024] FIG. 8 is an illustration of an example incorporate GRABBED content client display.
DETAILED DESCRIPTION OF THE INVENTION
[0025] In the following paragraphs, the present invention will be described in detail by way of example with reference to the accompanying drawings. Throughout this description, the preferred embodiments and examples shown should be considered as exemplars, rather than as limitations on the present invention. It will be apparent that the invention can be embodied in a wide variety of forms, some of which may be quite different from those of the disclosed embodiments. Consequently, the specific structural and functional details disclosed herein are merely representative and do not limit the scope of the invention. As used herein, the “present invention” refers to any one of the embodiments of the invention described herein, and any equivalents. Furthermore, reference to various aspects of the invention throughout this document does not mean that all claimed embodiments or methods must include the referenced aspects.
[0026] Generally speaking, a method of collecting, sharing, and tracking user or group associated content is provided in which the method includes the steps of: under control of a client system (“client” as used herein is also referred to as a “viewer”), displaying information identifying individuals or groups of individuals (also referred to as “users”) and their associated content; in response to an action being performed, indicating a desire to collect the content relating to the individual or group of individuals, sending a request to collect the requested content along with an identifier of the content requested; and under control of a server system, receiving the request from the client or viewer, retrieving additional information regarding the associated content, using the identifier in the received request, and adding the associated content to the requestor's associated content. It should be noted that all or a portion of these steps may be practiced in realization of the present invention.
[0027] In one embodiment of the above described GRAB BAG framework, individuals or groups (i.e. particular users) can specify who can collect their content and how it can be used. In another embodiment, collected content may be restricted in its use by the collector (or user) as facilitated by the technology (such as by the restrictions of various Creative Commons licenses: distribution [yes/no], modification [yes/no], attribution [yes/no]). In a further embodiment, the authoring individual or group can withdraw all instances or derived instances of content. Alternatively, another embodiment may allow the authoring individual or group to only withdraw the original instance of the content. In another embodiment, a GRAB BAG system allows individuals or groups, whether original or derivative authors, to view and manage the dissemination of their associated content. Instances of this invention could exists within a closed community, such as a social network. The GRAB BAG framework is meant to facilitate the sharing and collection of digital pictures, text, video, music, any other media, or advertisements.
[0028] An embodiment of the invention utilizes the GRAB BAG framework as a revenue model and/or to facilitate transactions between agents. In one example, associated content original or derivative authors are rewarded when individuals or groups (other users or viewers) collect their content. In another example, the rewards are privileges offered by a website, such as reward points, gift certificates, or extra quota space. In yet a further example, it allows associated content original or derivative authors to accept rewards (points, money) from requesters in order to allow their content to be collected. In another example, requestors trade content or rewards in order to collect content. Requestors may be required to pay in order to collect content. Such payments may take the form of payment to either the author or derivative author according to the size and type of content they collect (i.e. pay per file size of an image) while the service provider takes a percentage (which may be zero (0)). In a preferred embodiment, requestors are rewarded for collecting content (advertising images) and original authors are rewarded when people print pictures that they have uploaded. This could be extended to a system where requestors are rewarded by the service providing site (i.e. extra quota, gift certificates, reward points). In another aspect of the invention, a method of efficiently storing collected content in which the content is stored as a delta (or change) from its parent (i.e. an image collected an unmodified does not need to be stored twice), creates hierarchical trees of derivative work for efficient storage. A preferred embodiment of the invention also promotes or requires collectors to post comments or contribute to the content in order to collect it, facilitating a forum about the associated content. It should be noted that “content” as used herein can optionally encompass and refer to product descriptions or product purchase pages or links and the rewards associated with content can be granted based on purchases made by other users or viewers who click on or otherwise view the content or associated or linked webpages and purchase products or services. For example, the reward can be a percentage of a purchase price or a referral fee. Likewise, the “content” can optionally encompass and refer to advertisements and rewards based on the content can be based on any model, for example pay-per-click. In another example, the “content” can optionally refer to pay-per-view content or fee-for-view or fee for download content.
[0029] Referring to FIG. 1 , there is generally shown a method and system for collecting, sharing, and tracking user or group associated content via a communications network in accordance with the present invention (also referred to as a GRAB BAG system). The GRAB BAG system 1 . 0 includes a plurality of client devices 1 . 1 (such as may be accessed by the “users” or “viewers” discussed herein), each of which is coupled to a network 1 . 2 and, in turn, to a GRAB BAG server system (GBSS) 1 . 3 . Each client device 1 . 1 , of which one is shown in some detail and three others are represented in block form, is typically a personal computer, such as a Windows-based personal computer. It should be understood that client devices may also be laptops, PDA's, workstations, mobile phones, Internet enabled TV, etc. Each client device 1 . 1 preferably has an input device such as a keyboard and/or mouse and a display for communication with a user. The client device 1 . 1 preferably has communications software and a modem (or some other form of Internet connectivity, such as a DSL modem, cable modem, T-1 line, ISDN line, etc.). Communications software may be any software suitable for telecommunications, and is preferably browser software. The communications software is for communication over network 1 . 2 with a GBSS 1 . 3 . Network 1 . 2 may be, for example, the Internet.
[0030] The GBSS 1 . 3 is preferably a web application that displays contents authored by agents, where agents are individuals or groups and also optionally may include the users and viewers discussed herein. The GBSS 1 . 3 may be a wholly integrated web application, such as a web log and social networking web site, that allows users to decorate themselves with brands and shares the same web server 1 . 8 , database provider, and server side scripts. It should be understood that the GBSS 1 . 3 may be utilized by third party web applications. Examples of third party web applications include Blogger, social networking systems such as Friendster, instant messaging systems such as AOL Instant Messenger, and community oriented applications such as Ebay, and oPhoto, provided these services are modified to interface with the GBSS 1 . 3 .
[0031] The GBSS 1 . 3 typically includes, for example, a web server, which is characteristically a programmed computer, preferably one that supports a HyperText Transfer Protocol (HTTP), that handles document requests and provides other services, returning information to the requester. It should be understood that the web server may communicate by exposing web services which communicate XML, etc. It should be clear that the web server could be replaced by an application that functions as a server, such as a program that listens to a specific port for incoming request. Many suitable software programs for the web server exist, including Apache and “MICROSOFT” Internet Information Services (IIS). GBSS 1 . 3 , in addition to a web server, includes a server side scripting engine 1 . 6 , preferably PHP, available from php.net, connected to the web server for pre-processing an output from the web server before it is returned via the communications network. The server side scripting engine 1 . 6 also allows communication with a database server 1 . 7 , preferably Mysql, available from mysql.com, using the Open Database Connectivity (ODBC) protocol. Other similar server side scripting products could be used, such as Cold Fusion, ASP.NET technology. The database server 1 . 7 is generally configured as an SQL database, and, besides Mysql, other database systems could be used such as those available from Oracle, Informix, “MICROSOFT”, or Sybase. The GBSS 1 . 3 may also be a multi-server system, such as a web farm. The database server 1 . 7 is in communication with a database 1 . 9 in which the database server 1 . 7 stores content.
[0032] Referring to FIG. 2 , there is generally shown the high level flow by which a viewer 2 . 1 may add a piece of content to their GRAB BAG store in a GBSS 1 . 3 . It should be noted that “viewer” as used herein is a “user” who is viewing another user's content. At other times or simultaneously a “viewer” can be making his/her own content available to viewing by other viewers. A preferred example of this flow involves a viewer 2 . 1 viewing content in a web browser as illustrated with reference number 205 , the web browser also referred to more generally as a viewer client for Grab Bag system 4 . 1 . The web browser acts as the Viewer Client 4 . 1 , which displays content of a particular user and an option to grab their picture ( 210 ), for example. The user may indicate wanting to add another user's (for example Agent A's) content or associated content to his grab bag ( 215 ). In other words, a request is sent from the viewer's system to the grab bag server system (GBBS 1 . 3 ) ( 220 ). The GBSS 1 . 3 processes the request in any desired fashion, such as first receiving it from the web server, processing the appropriate PHP, accessing the Mysql database when necessary, and entering what is necessary in the database to store the association between the instance of the content where it was grabbed, the original instance, and the new instance where it is being grabbed to. The user's (Agent A's) content or associated content is then made available to the viewer to utilize via the viewer's GRAB BAG ( 225 ).
[0033] FIG. 3 is an example of possible process steps relating to the client-server interaction. A user (i.e. viewer 2 . 1 ) activates an action component in the client viewer 4 . 1 to initiate an adding of selected content to the user's GRAB BAG ( 305 ). According to one embodiment, this may be done, for example, by the user selecting a hypertext link such as by clicking or using any other input device, such as a mouse, keyboard, voice recognition software, touch-screen, light pen, etc. The client viewer 4 . 1 sends a request to the GRAB BAG server system 1 . 3 ( 310 ). In one embodiment, the request contains an identifier or plural identifiers indicating the content the user desires to grab and identifying the particular viewer 2 . 1 making the request ( 310 ). After receiving the request, the server system 1 . 3 begins processing it, such as using the server side scripting engine 1 . 6 ( 315 ). In this example, the server side scripting engine 1 . 6 optionally interacts with a database 325 (such as on the database server 1 . 7 ) to retrieve the content ( 320 ). The grabbed content is then stored in the user's (i.e. viewer 2 . 1 ) GRAB BAG. In other words, the grabbed item is added by the server system 1 . 3 into a grab bag storage system (such as in a storage unit such as database system 1 . 9 ) ( 320 ). The grab bag storage system for example includes a data structure, such as for example a table with columns for storing a userID identifying the viewer 2 . 1 grabbing the content, an itemID identifying the content grabbed and an itemType indicating the type of content ( 320 ). The itemType can optionally be the name of a separate table (i.e. a pictures table) ( 320 ). The itemID can be a unique identifier (i.e. uniqueID) for the item in that separate table (i.e. a pictureID) ( 320 ). Other records also can be retained relating to other pertinent information, such as regarding the user (i.e. viewer) who requested (i.e. grabbed) the content, the user whose content was grabbed, date and time information regarding the request, and possibly other information ( 320 ), such as in a fast lookup table. The original creator of the grabbed content also may be recorded ( 320 ).
[0034] FIG. 4 depicts the typical components required for a Viewer Client for a GRAB BAG System 4 . 1 . There are displays for two types of information, content 4 . 2 and collect requests 4 . 3 . It should be apparent that these two types of displays may be rendered by the client 4 . 1 in the same display, as a web browser does. For example the displays may be in different parts of the same window, different parts of a display screen, simultaneous, in separate windows etc. In one example, they may be in separate windows such as in a client application that separates advertisement display from content display, such as Kazaa Media Desktop, AOL Instant Messenger, or the iTunes Software Application. An action component 4 . 3 (such as a hyperlink, form submit, button, etc.) is activated by the viewer 4 . 1 to indicate a desire for an agent's content. This is typically assisted via the methods (also commonly known as input techniques or devices) that a web browser supports for interaction, such as keyboard input, mouse input, etc., but extends to other methods of interaction such as the utterance of a sound or the touching of a screen or the sending of an electronic mail message. Finally the GRAB BAG System 4 . 1 requires a method for communication with a server system 4 . 5 , typically this is TCP/IP used by the web browser.
[0035] FIGS. 5 and 6 illustrate database schema 500 for a plurality of data objects 505 . The data objects 505 may include objects relating to, for example, blog entries, blogs, class gallery, class cache, class blog entry, class picture, class list item, class list, class blog, electronic mail confirmations, friends, second degree friends, gallery rows, gallery images, galleries, gallery image instances, gallery directories, errors, lists mind, list mind items, reaction blogs, reaction blog entry, reaction gallery, reaction list, reaction list item, reaction picture, reaction user, session browse paths, sessions, user contact settings, user profiles, users, page views, messages, invites, interests, and last viewed friend requests.
[0036] Each data object 505 may include a data object name 510 , data object identifier 515 , and data object information 520 . The data object name 510 may be a name assigned by a programmer, administrator or other user of a system for constructing a networking database and system proactively. The data object identifier 515 may be an identifier that is used by the system for retrieving that data object. The data object information 520 may include information relating to that data object 505 . For example, an errors data object 505 may include a data object name 510 titled errors. The data object identifier 515 may be titled errorsID. The data object information 520 may be information relating to errors encountered while the system is being used. For example, the data object information 520 for an errors data object 505 may include an error description, code, location, date, and sessionID. This information assists a programmer, administrator or other user in determining how to correct the error.
[0037] FIG. 7 is an exemplary illustration of screenshot 700 showing how content may be GRABBED. The web page 700 may include one or more selectable operations, such for example via tabs 705 as illustrated or any other means. The option selector icons 705 may be selected using, for example, a convention keyboard, mouse, touch-screen, voice recognition software, etc. The web page 700 may also include a web page identifier 710 that identifies the viewer or the viewer's page being viewed. The web page 700 may include a preview pane 720 that presents a preview of an item located in a user's pouch 725 . For example, if an item in at least one of the pouches 725 is selected, that item is displayed in the preview pane 720 . The item may be, for example, an image, text, video, audio etc. The viewer 2 . 1 may examine the item in the preview pane 720 to determine whether to grab that item and add the item to the viewer's content. The item may be grabbed and added to the viewer's content by, for example, clicking and dragging the item to the tab 705 labeled “My Metails” or via any other action sufficient to send a grab request to a server. The viewer may then drop the item into the viewer's content using known or desired techniques. Alternatively, the viewer may select an icon, such as the “Grab Bag® It” icon displayed in a ratings field section (described in further detail below) of the web page 700 .
[0038] Each pouch 725 may be, for example, a subset of the user's content. The pouches 725 may hold a predetermined number, for example, eight (8), of items, or may be expandable or contractible to any number of content items. In one embodiment, a pouch is of limited size, and when a predetermined number of items in the pouch has been reached, an additional pouch 725 may be created. The items in each pouch 725 may be displayed as thumbnails. In one embodiment, a particular pouch 725 may be selected using pouch selectors 730 . In one alternative embodiment, a limited number of pouches 725 are displayed on a web page 700 and if a viewer desires to see items in a pouch 725 that is not displayed, the viewer may select another pouch using the pouch selectors 730 .
[0039] A message field 735 may also be included in the web page 700 . The message field 735 enables the viewer to post a message to the user whose content is being viewed. The message field 735 may enable the viewer to share the message with only the user, the user and his network or possibly other options.
[0040] The web page 700 may also include a ratings field 740 . The ratings field 740 may provide ratings for particular content associated with a user. The ratings shown may be average ratings for a particular item, the viewer's rating for the item, average rating for the user's particular content, such as a gallery of items, the viewer's rating for the gallery, etc.
[0041] A connection field 745 may be provided to indicate whether the viewer is logged-in. If the viewer is logged-in, the connection field 745 may include a log-out option. If the viewer is not logged-in, the connection field 745 may include a log-in option.
[0042] FIG. 8 is an illustration one example of a web page illustrating how grabbed content optionally may be incorporated after being GRABBED. In this example, illustrated web page 800 is presented to a viewer upon grabbing another user's content and adding that content to the viewer's content. The web page 800 may include one or more matrices 805 that displays items in a content gallery such as via viewable or hearable thumbnails. A gallery title 810 may be used to identify the galleries that are being viewed. Each gallery may include one or more pouches 815 (described above). Modifying functions 820 may be displayed that enable the viewer to edit and/or delete one or more items in the gallery when selected. A “Create New Picture Gallery” option 825 may also be presented. The “Create New Picture Gallery” option 825 enables the viewer to create a new picture gallery with content. The content may include previously grabbed content, newly grabbed content, uploaded content or other content.
[0043] Gallery options may also be displayed. The gallery options may include, for example, cancel option 830 and save option 835 . The cancel option 830 enables the viewer to cancel any modifications made to a gallery before the modifications have been saved. The save option 835 enables the viewer to save any modifications made to a gallery.
[0044] A gallery tray 840 may also be associated with a gallery. The gallery tray 840 may be used to store items desired to be saved by the viewer but not desired to be available to other users. For example, a viewer may upload a picture to his/her content, however, the viewer does not desire that other users be able to view the picture until a later date. The viewer may simply place the picture in the gallery tray 840 associated with a desired gallery. When the viewer desires the picture be made available to other users for viewing, the viewer may move the picture from the gallery tray 840 to a desired pouch. If, however, the viewer decides that he/she does not wish one or more particular items to be viewed by other users, the viewer may move the particular items to the trash can 845 using known techniques.
[0045] Thus, it is seen that a method and system of collecting, sharing, and tracking user or group associated activity via a communications network is provided. One skilled in the art will appreciate that the present invention can be practiced by other than the preferred embodiments which are presented in this description for purposes of illustration and not of limitation, and the present invention is limited only by the claims that follow. It is noted that equivalents for the particular embodiments discussed in this description may practice the invention as well. | A content collection, sharing, and tracking method and system allows individuals or groups to incorporate the content of one another into their own context for creative referenced re-use. Users browse the content of other users and add content to a tool known as a GRAB BAG. Users may be part of affinity groups such as social networks or have common interests such as an interest in a single Internet auction site. The GRAB BAG storage system keeps track subsequent revisions and contexts for the piece of content in all instances where it is grabbed. When users incorporate the content they have grabbed into their own content, it appears with a link to the original author as well as with links to track the dissemination of the original content. The GRAB BAG storage system is created to reference content so that identical items under two different contexts need not be duplicated in full. | 6 |
BACKGROUND OF THE INVENTION
This invention relates liquid ring vacuum pumps in general and more particularly to an improved pump set comprising a liquid ring vacuum pump preceeded by a compressor.
Pump sets consisting of a liquid ring vacuum pump preceeded by a compressor, such as a Roots pump are well known in the art. Devices of this nature are used for suctioning and compressing media in gaseous or vapor form down to a vacuum of 100 Torr. Because displacement pumps such as Roots pumps are relatively complicated in design and require a large amount of maintenance, jet pumps have been used as precompressors in many applications. This is true even though this requires tolerating a larger liquid ring vacuum pump because it must also handle the operating fluid used in the injector pump.
Thus, neither of the methods of implementing such a pump set in the prior art are completely satisfactory. In view of this, it is the object of the present invention to provide an improved pump set of this nature which combines great ruggedness, reliability, small space requirements and has comparatively low power requirements with respect to the intake volumne.
SUMMARY OF THE INVENTION
The present invention solves this problem by using as a compressor preceeding the liquid ring vacuum pump, a side channel ring compressor and by matching suction capacity of the liquid ring vacuum pump to the pressure ratio attainable with the side channel ring compressor.
A side channel ring compressor is the type of compressor or pump disclosed in French Pat. No. 1,382,230, the title of which translates to "Annular Ventilator Based On the Principle Of A Side Channel". Such a device is more commonly known as a regenerative turbine pump and such is disclosed, for example, in U.S. Pat. No. 3,558,236. Examination of that patent will show where the term side channel comes from since the housing of the pump is formed with what are side channels in which the material being pumped circulates.
Through this arrangement the liquid ring vacuum pump need no longer be of sufficient capacity to handle the additional operating medium for an injector pump. As a result, the required total drive power can be considerably reduced and the structural size of the overall pump set made smaller. In accordance with the present invention, means are preferably provided to prevent an impermissable increase of the side channel ring compressor's power consumption when the latter is turned on. One disclosed manner of accomplishing this is by means of controlling the speed of the ring compressor as a function of power consumption, particularly during the starting phase of an evacuation. Power consumption is proportional to the specific gravity of the medium to be compressed and to the pressure difference obtained. Thus, in the simplest case the drive of the liquid compressor is turned on and off in dependence on the pressure. Furthermore, in conjunction therewith it is advantageous to provide a buffer chamber between the ring compressor and the liquid ring vacuum pump to prevent shock-like operations.
Another possible solution which is disclosed comprises providing a return line containing valves controlled as a function of pressure between the pressure side and suction side of the side channel ring compressor. This permits using the line as a bypass for the side channel ring compressor during the starting phase and also permits the return of the pump medium, assuming appropriate throttling, to avoid building up too high a pressure difference in the side channel ring compressor. Since, as noted above, the power of the electric drive of the side channel ring compressor is proportional, among other factors, to the pressure difference and the density, it is also possible to use the current of the electric drive motor to determine power consumption. Then, in dependence on the measured current, the speed and/or current of the drive motor can be limited.
In many applications the drive power may be made pressure dependent through the use of elastic blades in the side channel ring compressor. This is true because, when matched correctly, the elastic blades will permit the buildup of a pressure difference only corresponding to the deliverable motor power.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a series of curves illustrating the operating characteristics of various combinations of compressors and liquid ring vacuum pumps.
FIG. 2 is a schematic diagram of the present invention.
FIG. 3 is a schematic diagram of an alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a number of curves helpful in understanding the manner in which the present invention provides a more effective and efficient pump set. On the figure, curve a is a characteristic curve of a liquid ring vacuum pump. On this curve, pressure is plotted against suction capacity. As is evident, suction capacity decreases below 100 Torr due to the evaporation of the liquid ring which typically might be water. To expand the field of application of the liquid ring vacuum pump, a gas jet pump injector can be placed ahead of the liquid ring vacuum pump in well known manner. As a result, for pressures under 40 Torr, for example, the characteristic curve designated b will result for the entire set. During an evacuation the medium to be compressed is then compressed by the jet pump along the line d from the operating point having a pressure P 1 to the intermediate pressure P 2 .
Also plotted on this diagram is the characteristic curve c of a side channel ring compressor in conjection with a liquid ring pump [characteristic curve a']. Assuming that the liquid ring compressor has a compression ratio of 2 to 1, it is evident that at the same initial operating pressure P 1 compression to the intermediate pressure P 2 takes place along the line e. As a result, a side channel ring compressor can be followed by a liquid ring vacuum pump of considerable suction capacity, i.e. characteristic curve a'. Thus, less drive power is required to obtain the same actual volumetric delivery. As a rough assumption, it can be said that for the compression ratio stated the structural size and thus the capacity of the liquid ring compressor and its power requirements can be cut approximately in half. As a result, a 10% power requirement which is needed in addition for the side channel ring compressor is of no consequence at all in the overall balance.
FIG. 2 is a schematic illustration of the present invention. Shown is a side channel ring compressor 4 connected to a space 1 having a pressure P 1 which is to be evacuated. The pressure of side channel ring compressor 4 communicates through a connecting line 5 with the suction side of a liquid ring vacuum pump 3. Liquid ring vacuum pump 3 compresses the pump medium from the intermediate pressure P 2 to the output compression pressure P 3 . This will normally be atmospheric pressure, i.e. approximately 760 Torr. Normally upon starting up the space 1 will be at atmospheric pressure or almost at atmospheric pressure. Under these circumstances, the side channel ring compressor 4 is bypassed by a bypass line 6. Once a sufficient vacuum has been achieved in the space 1, e.g. a vacuum of 40 Torr, a pressure sensor 8 causes a control valve 7 to shut off the bypass line 6 and through a control signal over a line 16 operates a control device 11 to start up the motor 10 driving the side channel ring compressor 4. This avoids in inadmissibly high power consumption for driving the side channel ring compressor. Other means may be provided to do essentially the same thing. For example, as shown on FIG. 3, a pressure sensor in the form of a pressure switch 9 may be installed to measure the differential pressure across the side channel ring compressor 4. This pressure difference is one of the main factors which covers the drive power needed by the drive motor 10. If it exceeds a certain predetermined value an output from the pressure switch 9 over the line 14 acts upon the control device 11 to control the speed of the motor 10. In the simplest case such a signal can be used to switch off the motor until the pressure between the side channel ring compressor and the liquid ring vacuum pump has been sufficiently relieved. Also, as illustrated by a control line 15, the control valve 7 can be driven from the pressure switch 9. Should an inadmissibly high pressure difference result across the side channel ring compressor the valve can be opened to permit a portion of the pump medium to be recirculated.
The side channel ring compressor 4 can also be constructed with flexible, i.e. elastic, blades in its impeller. If the elasticity of these blades is properly selected, they will limit the drive power of the compressor 4 to the level which is permissible.
Further, with regard to the pressure switches 8 and 9 it should be noted that these will be conventional devices providing a switch closure when a preset pressure is reached. The control 11 in its simplest case can simply comprise contactors responsive to these switch closures. The control valve 7 may be a conventional motor controlled valve operable between two limits. In the appropriate cases it too may simply respond to the switch closures provided by the switches 8 and 9.
Thus, an improved pump set for drawing and maintaining vacuums under 40 Torr has been shown. Although specific embodiments have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made without departing from the spirit of the invention which is intended to be limited solely by the appended claims. | A pump set comprising a compressor followed by a liquid ring vacuum pump with the two pumps matched to each other so that a relatively small liquid ring vacuum pump can draw and maintain vacuum under 40 Torr. | 5 |
[0001] The present invention consists in a matrix containing a compound of a transition metal which confers antimicrobial properties and a method for incorporating said compound of a transition metal in a matrix of animal, vegetable or synthetic origin, with a uniform distribution and with high level of fixation.
[0002] The present invention relates more particularly to a matrix containing a copper compound, which confers antimicrobial properties to the matrix. The present invention also relates to a method for incorporating this copper compound to the matrix.
[0003] The incorporation of particles of compounds containing transition metals, mainly copper and silver, to solid matrices, such as a fabric or leather, is commonly done through copper particles or copper wires, where the metal is at zero state, i.e., metallic state, so it must be oxidized to release and activation and thus act as an antimicrobial agent. At the same time, products presenting copper wires as part of its internal structure do not provide concentration gradients of antimicrobial agent that feature activity on one side of the matrix and not on the other.
[0004] In the state of the art, there are some solutions to deliver antimicrobial properties to different surfaces using copper, this by macro dispersion, which generally has low effectiveness.
[0005] The document U.S. Pat. No. 8,183,167 (B1) of 2012, they are submitted substrates for fabrics which exhibit antimicrobial properties and/or antifungal which persist through the life of the substrate, and more particularly to textile substrates infused with, or covalently bonded to, antimicrobial or dispersed nanoparticles, such as silver and/or copper nanoparticles, which exhibit bactericidal bacteriostatic capabilities, with fungicidal fungistatic behavior through many wash cycles. Production methods of such substrates are also presented. One of the claims indicates that it is a substrate for 1% of synthetic polymer fiber for textiles.
[0006] The present invention differs from the solution proposed in U.S. Pat. No. 8,183,167 (BI), given that it is not required to control the size of particles to be incorporated into the matrix, and furthermore, the present invention is directed to matrixes of natural origin, on the contrary, the solution proposed in U.S. Pat. No. 8,183,167 (BI) is directed to synthetic polymers. Additionally, the process proposed by the present invention is a procedure where a number of physical stages are used for fixing the product, which confers antimicrobial properties, as the compound is incorporated into the matrix homogeneously.
[0007] The document U.S. Pat. No. 8,105,635 of 2010 describes post-treatment compositions and methods useful for changing the distribution of metal biocide in biodegradable substrates such as wood, other cellulosic products, starch based products, and the like that are vulnerable to decay due to insects, fungi, microbes and the like. In this document, it is claimed a method for treating biodegradable substrates with biocide compounds such as copper.
[0008] U.S. Pat. No. 7,754,625B2 of 2010 describes an antimicrobial textile comprising one or more natural or synthetic fibers or filaments having associated therewith an antimicrobial agent, wherein said antimicrobial agent comprises a predominant amount of a soluble zinc salt in water in combination with at least one source of antimicrobial silver ions and at least one source of copper ions, which can be of the same source as the source of silver ions.
[0009] The document US 2008/0311165 (AI) of 2005 describes a method for treating and curing ulcers, cold sores, cutaneous openings, ulcerations, lesions, abrasions, burns and skin diseases, which comprises applying to a surface of its exhibited body, a material incorporating water in soluble copper compounds which release Cu+ ions, Cu++ ions or combinations thereof upon contact with a fluid to make the treatment and healing thereof effective.
[0010] Herein it is indicated that the material is a fabric having water-insoluble fibers incorporating copper compounds. The fibers are coated with copper compounds. In the process of generation of the fiber, raw material is heated from 120 to 180° C. and the copper oxide is added.
[0011] Meanwhile, in document U.S. Pat. No. 7,169,402B2 2007, it is disclosed an antimicrobial and antiviral polymeric material having microscopic particles of ionic copper encapsulated therein and protruding from surfaces thereof.
[0012] Antimicrobial and antiviral polymeric material is disclosed, comprising a polymer selected from the group consisting of polyamide, polyester and polypropylene, and one anti-microbial and anti-viral component, consisting essentially of microscopic particles of copper oxide insoluble in water incorporated in the polymer, wherein a portion of the particles in said polymer are exposed and protrude from the material surface.
[0013] The document U.S. Pat. No. 4,201,825 of 1998 relates to a metallized textile. The invention also relates to a process for producing such a metallized fabric by deposition of metal (copper, nickel) without current, preferably at room temperature where the activation of the material is effected in a solution of colloidal palladium, preferably at room temperature.
[0014] Wherein, the metal is present in the fabric in a coating of at least 0.3 μm thick. The coating is added through metal salt baths, preferably bath of nickel salts, cobalt salts or mixtures thereof, copper salts, gold salts or other salts that can be deposited from alkaline baths.
[0015] In U.S. Pat. No. 7,296,690B2 of 2007, it is described a device for inactivating a virus comprising a housing delimiting a fluid conduit, wherein the conduit is provided with a filter material having ionic copper selected from the group consisting of Cu+ and Cu++ ions and combinations of them incorporated. The device has a filter with copper powder or associated with fibers.
[0016] The document U.S. Pat. No. 7,364,756B2 2008, describes a method to confer antiviral properties to a hydrophilic polymer, which comprises preparing a hydrophilic polymer suspension. In this hydrophilic material, it is added a mixture of water insoluble particles that release both Cu++ and Cu+, wherein said particles are in proportions 1 to 3% w/w in the material. The hydrophilic material (such as that used for manufacturing disposable gloves and/or male condoms) is cured as it passes through different areas of the oven and is exposed to temperatures ranging from about 120 to 140° C. This cross-linking process bonds the rubber latex to impart the required physical qualities. The difference between the normal process of manufacturing a disposable material and this document method is that in the latest, it is added insoluble particles containing ions Cu++ and Cu+ which are then released into raw materials. The document U.S. Pat. No. 5,405,644 of 1995 describes a process for producing a fiber having a microbicide inorganic antimicrobial containing silver, characterized by using a treatment solution for producing the fiber containing a discoloration inhibitor. The method for supporting silver has no particular restriction. The supporting method can be exemplified by a method comprising kneading a resin that was made into a fiber and a microbicide and subjecting the mixture to spinning, and a method which comprises applying a microbicide mixed with a binder, to the surface of a fiber spun by coating, dipping or similar. The document U.S. Pat. No. 5,399,425 of 1992 describes a method using polymer substrate (NHRCO—a polymer having at least one repeating unit) and it is first treated with a solution of a strong base to generate anionic surface sites. The treated structure is put in contact with a solution of metal cation (group 8 to 12 periodic table) desired adhering to it through ion exchange. The process of the invention can be performed at temperatures between 17° C. to 190° C. The preferred temperature is room temperature about 60° C. The process may be more conveniently performed at a subatmospheric pressure of 35,000 psig.
[0017] The patent W09806508 of 1999 describes a process for the activation of a textile to catalyze the reduction of a metal cation (Cu, Ag, Zn, Ni, CuO, Ag 2 O, ZnO and NiO), a metallization process for textile. The textile is immersed in a properly prepared solution of a metal cation and adding a reducing agent; this leads to the formation of a sealed metal coating and intimately bonded to the fibers of the fabric.
[0018] The document W09806509 (AI) of 1998 describes the use of metallized textile. The textile is activated precipitating nucleation sites of a noble metal on the textile fibers. The method comprises the steps of:
[0019] (a) providing a metallized textile, the metallized textile comprising: (i) a fabric including selected fibers from the group consisting of natural fibers, synthetic fibers, regenerated cellulosic fibers, acrylic fibers, polyolefin fibers, polyurethane fibers, vinyl fibers and fiber mixtures of them, and (ii) a plating including materials selected from the group consisting of metals and metal oxides, the metallized textile characterized in that the lining is directly bonded to the fibers and (b) incorporating the metallized textile in an article of manufacture.
[0020] The same process described above, is mentioned in other patents and prior art, with reference to W09806509. In these cases, the procedure is described according to the following steps: a) selecting a textile, in a form selected from the group consisting of yarn and fabric, said textile including fibers selected from the group consisting natural fibers, synthetic cellulosic fibers, regenerated protein fibers, acrylic fibers, polyolefin fibers, polyurethane, vinyl fibers, and mixtures of them; b) soaking said textile in a solution containing at least one reducing cationic species having at least two positive oxidation states; c) soaking said textile in a solution containing at least one kind of noble metal cation, thereby producing an activated textile, and d) reducing at least one oxidant cationic species in a medium in contact with said active textile, thereby producing a textile metallic.
[0021] The document W00075415 (AI) of 2000 introduces an article about clothing having antibacterial and antifungal, comprising at least one panel of a textile (natural fibers, synthetic cellulosic fibers, regenerated protein fibers, acrylic fibers, polyolefin fibers, polyurethane fibers, vinyl fibers, and blends of them) and having a coating including antibacterial and antifungal effective amount of at least one oxidant cationic species of copper. In this document, there are two steps shown in the process of production of the fabric: The first step is activation of the textile by precipitating catalytic metal nucleation sites. This is done soaking the textile in a solution of a reducing cation of low oxidation state and then soaking the textile in a solution of noble metal cations, preferably a solution of Pd++, more preferably an acid. The second is a reducing metal cation. The metallized textiles thus produced are characterized because their metallic coating is bonded directly to textile fibers.
[0022] The document W09600321 (AI) of 1996 refers to a fiber material used for the production of textile products such as woven fabrics, nonwoven fabric, paper, among others similar. The method for producing an antibacterial fiber comprises the following steps: bonding, through an ion exchange reaction, the complex ion of silver, copper or zinc with the ion of the exchange group of fiber with cation exchange, which has a sulfonic group or a carboxyl group as the ionic exchange group; and then the complex ion is reduced.
[0023] The document TW201018762 of 2010 (Taiwan) describes an antibacterial textile with bleaching which includes a textile substrate, an aqueous resin and an antibacterial powder. The surface of the textile substrate is covered with the aqueous resin. The antibacterial powder is distributed in the aqueous resin; said antibacterial powder includes silicon dioxide particles and silver nanoparticles which are synthesized with each other. Additionally, the antibacterial powder and methods of making the aforementioned antibacterial textiles are included in the patent.
[0024] The document US2006156948 of 2006 refers to ionic coatings of silver based in antimicrobial, particularly erosive coatings having improved color stability without compromising the level of active antimicrobial silver. In particular, this document is directed to antimicrobial coatings containing agents of ion exchange antimicrobial type, especially zeolites, having excellent antimicrobial properties without discoloration due to the formation of silver compounds. In this document, copper compounds are also mentioned as a substitute for silver ions.
[0025] The document W09415463 (AI) of 1994 describes an antimicrobial composition comprising an inorganic particle (copper, silver) with a first coating providing antimicrobial properties and a second coating providing a protective function, the patented method for preparing the composition and its use. Other processes for the production of polymer items and also describes a method for controlling microorganisms. The steps in the present invention are: (a) forming an aqueous suspension of material particles core; (b) depositing a first coating of the desired antimicrobial component or components on the core particle surface with suitable precipitation reactions; (c) depositing a secondary protective silica and/or alumina coating by adding an alkali metal silicate or aluminate to the suspension, keeping the pH, (d) optionally, it is applied a coating of a hydrous metal oxide by treatment of the particles suspended with a salt; (E) recovering the solids, washing free from water soluble species and drying; and (f) optionally adding steam micronization.
[0026] The document DE102007048107 (AI) of 2009 (Germany) describes an antibiotically active substrate for seeding purposes in the production of materials such as dyes, papers, clothes, chamfer and materials and supplies, preferably suspensions for surface coatings, comprising active nanomaterial with antibiotic properties; arrangement made from a continuous metallic coating with a highly porous surface or in connection with a porous substrate which forms a corrosion cell where continuous nano-porous metallic surface is formed with a high surface area of silver, copper, zinc, mercury, tin, lead , bismuth, cadmium, chromium and thallium metal as an antimicrobial.
[0027] The document W00181671 (A2) of 2001 describes a method for the treatment and prevention of nosocomial infections. This method comprises incorporating into fabrics or textiles used in health, fibers coated with an oxidant as cationic form of copper. Such fabrics may be used in contact with the patient for care or medical use in which the fabric is effective for the inactivation of bacterial strains resistant to antibiotics.
[0028] Meanwhile, the document R0117626 (BI) of 2002 (Romania) relates to a process for obtaining cotton fabrics with a metal coating consisting of roughness, wherein said metal is particularly copper. This procedure consists of preparing an alkaline solution comprising 550 g/L of ethylene glycol and 60 g/L of sodium hydroxide, neutralization is carried out subsequently, and it is sensitized with a solution containing hydrazine hydrate, chemically activating the coating metal. The copper plating solution has a mixture of salt, which is fixed electrochemically sodium tellurate.
[0029] In the scientific article of the Journal ECI Peru, vol. 8, No. I, January 2011, “Synthesis of nanostructured copper oxide assisted with gamma irradiation or ultrasound and its antimicrobial properties,” it is described the synthesis of oxide nanoparticles (CuO) by gamma irradiation or ultrasound. The antimicrobial activity of CuO nanoparticles was determined by the method of excavation in culture plate with 3 microbial strains: Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. The CuO nanoparticles are nanospheres obtained by ultrasound with a higher antimicrobial activity for S. aureus bacteria than for E. coli and no activity against P. aeruginosa; while CuO nanoparticles obtained with gamma radiation with a dose of 8 kG have antimicrobial activities similar for S. aureus and E. coli , and those obtained at doses of 15 and 25 kG only have antimicrobial activity against E. coli. In this article, the results of CuO nanoparticles impregnated in cotton fabrics are also presented in order to demonstrate its potential use in such matrixes.
DESCRIPTION OF THE INVENTION
[0030] The present invention relates to a matrix of animal, vegetable, or synthetic origin or any proportion of the above, containing a compound of a transition metal, particularly copper, where the matrix has antimicrobial properties.
[0031] This matrix with antimicrobial properties, or the supporting tissue or material, is impregnated and incorporated with Alkaline Copper Sulfate, formula CU 4 SO 4 (OH) 6 , which corresponds to a molecular rearrangement of copper sulfate pentahydrate Cu4 S O 4 .5H 2 O. This alkaline copper sulphate is characterized by a very low solubility and low diffusion when incorporated in the matrix, whereby it is obtained that the matrix maintains its biocide properties even after consecutive washes.
[0032] According to the above, the active ingredient is incorporated into the matrix is preferably alkaline copper of formula (CU 4 SO 4 (OH) 6 ), which is an insoluble compound that is obtained from copper sulfate pentahydrate in aqueous ammonia (or ammonium hydroxide) according to the following reactions:
[0000] CuSO 4 .5H 2 O+4NH 3 Cu(NH 3 ) 4 2+ +SO 4 2− +5H 2 O
[0000] Cu(NH 3 ) 4 2+ +SO 4 2− +H 2 O CuSO 4 .4NH 3 .H 2 O (pp)
[0000] 4CuSO 4 .4NH 3 ·H 2 O+5H 2 O Cu 4 SO 4 (OH) 6(pp) +3SO 4 (NH 4 ) 2(soluble) +10NH 3(g)
[0000] NH 3(g) +H 2 O NH 4 + +OH −
[0033] The sulfate of alkaline copper for this invention is preferably obtained from copper sulfate pentahydrate, according to the above mentioned reactions, however, to prepare the solution, it is required the presence of copper cation +2 and sulfate anion −2, therefore, raw materials used may be of any chemical compound containing said cation or anion, either in the same compound, such as copper sulfate, or in different compounds such as copper chloride, copper oxide, copper phosphate, which provides the copper ion with chemical compounds that contribute the sulfate radical as sodium sulfate, potassium sulfate, ammonium sulfate, among others, or copper sulfate in any state of hydration, or a mixture of oxide copper or copper hydroxides neutralized with sulfuric acid.
[0034] In the preparation of the active ingredient, it is required the presence of ammonium hydroxide, which is generated from ammonia added to the system in liquid, gaseous form or through form ammonium salts soften with hydroxide salts.
[0035] In this process, it is produced a reaction intermediate corresponding to CuSO 4 .4NH 3 .H 2 O, from which fixing alkaline copper sulfate (Cu 4 SO 4 (OH) 6 ) is obtained by heat treatment. The reaction conditions require a small excess of free ammonia non-ncomplexed in order to ensure the formation of the intermediate compound and minimize other chelation states of copper with ammonia.
[0036] Preparation of the Impregnation Solution.
[0037] As noted above, it is required to impregnate the matrix with ammonia or ammonia solution, containing a small excess of free ammonia non-ncomplexed, favoring the formation of the intermediate compound once evaporated or exposed to air the excess solution.
[0038] The ammonia formula has 5% copper in the solution, which equates to be practice to a 20% copper sulfate pentahydrate plus sufficient ammonia to ensure chelation of copper to form the intermediate compound CuSO 4 .4NH 3 .H 2 O.
[0039] Impregnation Procedure for Different Matrixes.
[0040] The present invention also relates to a method of impregnating copper compounds into a solid animal, vegetable, synthetic or any blend in different proportions among the above materials, which confer antimicrobial properties to said matrix. Such material may be any surface which is permeable to water. Said process allows to obtain a homogeneous distribution of the compound and with different concentrations, independent of the material used, to obtain a desired matrix for various uses.
[0041] This procedure can be used on various materials, it being understood as the basis matrix for any surface that allows the incorporation of the compound, such as: fabric (any quality, texture or thickness), paper (any quality, texture or thickness), natural and synthetic leathers (any quality, texture or thickness), or any material containing any proportion of the above materials.
[0042] The procedure involves the following steps:
1) Absorption/Impregnation.
[0044] In this stage, it is added the ammonium cooper sulphate solution containing the intermediary or other compound containing copper ions and ammonium ions, into the base material in order to form the matrix according to the use requirements of said matrix. This step is intended to incorporate the active ingredient distributed evenly, using the characteristics of the material, such as permeability, capillarity and wetting, to form the matrix.
[0045] For preliminary impregnation, the material used shall be immersed for a period to ensure it is completely wet and the distribution of the impregnating solution.
[0046] The periods required at this stage are between 5 to 30 minutes, particularly about 10 minutes, and only for standardization, they shall must be verified the desired final copper content. This operation is performed at room temperature (about 20° C.).
2) Spinning/Pressing/Crushing
[0048] This stage aims to standardize, delete, and dose much of the excess of the preparation of the dilution, achieving controlled concentrations of the active ingredient (copper) in the matrix.
[0049] It is removed by any mechanical means the surplus of aqueous solution of copper sulfate with ammonia to leave copper concentrations required by the end use of the matrix. The mechanical means to choose can be spinning, pressing or crushing, the choice depends on the characteristics of the material which is being handled to achieve the desired antibacterial matrix.
3) Exposure to Air
[0051] At this stage, the exceeding aqueous ammoniacal solution is evaporated over the intermediate compound being CuSO 4 .4NH 3 .H 2 O.
[0052] The airing is intended to maintain uniform distribution and homogeneity of copper in the matrix, to avoid the existence of localized and uncontrolled migration (e.g., drips, liquid displacement copper displacement in the solution etc.).
4) Fixation and Production of the Active Ingredient
[0054] The fixation technique allows adhesion with uniform distribution, also can provide a property with homogeneous concentration gradient from one side to another of the matrix or concentrations focused on different areas of the matrix.
[0055] This is achieved by giving adhesion properties to the active substance, alkaline copper sulphate, with temperatura application; this temperature application can be of any nature which does not impair fixing substrate of the matrix.
[0056] In order to transform the reaction intermediate, copper ammonia sulfate CuSO 4 4NH 3 .H 2 O into final insoluble alkaline copper sulfate Cu 4 SO 4 (OH) 6 in the desired or required matrix sectors, is required to apply between 50 and 120° C. temperature depending on the base material used to form this matrix and periods will be given according to the degree of resistance of the base material used to form the matrix.
[0057] The shorter periods and higher temperatures required to achieve the transformation of the intermediary to set final product, shall be conditional upon the strength, integrity and aesthetics of the resulting base material used.
[0058] It is noteworthy that the process described above can be used to fix copper hydroxides or oxides that accomplish the same objective of alkaline copper sulfate, using raw materials hydroxides or oxides of copper plus ammonia in gas or liquid state. With this methodology, it is not obtained nanoparticle distribution, but an incorporation of the compounds into the matrix.
[0059] The procedure described above allows the compound to be uniformly occluded inside, outside and between the fibers of the matrix, unlike the nanoparticles distribution technique which leaves interstitial spaces not protected by the active ingredient, which would allow the subsistence probability of pathogenic uncontrolled population.
[0060] FIG. 1 shows how the copper compound is incorporated into the matrix. By electron microscopy, it was determined that all the fibers of the fabric contain a copper compound even when under 16 pm the compound particles cannot be appreciated. It has been determined that the compound molecules are homogeneously distributed in the fibers, which provides antimicrobial properties to the matrix. Furthermore, it allows the uniform distribution of particles in the matrix of the formulation, with different gradients concentrations, and can be fixed on only one or both sides of the matrix, or in specific areas of this.
[0061] This procedure makes the compound adhere and fix to the matrix, presenting high adhesion, even after washing (home or industrial) and repeated use. The matrix impregnated with alkaline copper sulphate, using this procedure, has antimicrobial properties that act with contact immediately and continuously thanks to its chemical state and distribution. Alkaline copper sulfate is occluded and fixed in the matrix uniformly both inside and outside, and even among the fibers.
[0062] The compound, alkaline copper sulphate occluded and fixed to the matrix, is an insoluble precipitate in the presence of humidity (ambient humidity and that of the microorganisms which are in contact with). It leaves free ions which rearranged again into the form of soluble dissociated copper sulfate; process that occurs slowly under control. Said soluble dissociated CuSO 4 , due to the characteristic of high solubility, leaves immediately cupric ions available in the humid environment, which finally exert the biocidal effect of high activity, which manifests itself in time, in a gradual and controlled manner.
[0063] This property of insolubility of the precipitated alkaline copper sulphate doses ions in the medium in the presence of moisture, this dosage is minimal in mass ratio of copper occluded in the matrix, and which ensures durability and permanence in time, even when multiple washes were performed.
[0064] The greatest losses will be given by the possible washing of the matrix, but these are minimal in relation to the mass of the fixed and occluded compound. Because of the antimicrobial properties (particularly antibacterial and antifungal properties) that acquires the matrix, it is possible a variety of uses, as the biological properties of the parent applications are combined. Prominent among these uses, but not limited to fabrics, paper, cardboard, leather, among others, with hospital use as blankets, bedding and hospital clothing, bandages and dressings for burned people, bandages and dressings for general use, because the matrix acts as a barrier against pathogens; with anti-odor use for odors produced by microorganisms, such as T-shirts use, sports clothing; antifungals, such as use in matrixes for underwear and socks; use as a disinfectant, for example, wipes or the like; veterinary use, such as in clothing animals; special clothing, such as clothing for diabetics, facial wipes (for example against acne); and others such as fabrics for insoles and shoes; cleaning paper, carpets, mattresses, curtains, sofa, furniture fabric, blankets, jackets, towels, disposable sterilization papers, food container papers based on paperboard, diapers, sanitary towels, garbage bags, paper filters for aeration, purification systems, etc.
EXAMPLE 1
Preparation of the Impregnation Solution to be Incorporated into a Matrix
[0065] The formulation is used in dilution with water, the concentration of which depends on the use and characteristics of the matrix to be impregnated. For example, for an array with a final concentration of 3% copper, the calculation is made using the following:
[0066] Matrix of dry mass (e.g. cotton fabric): 1000 g.
[0067] Copper percentage required in the final matrix occluded 3%
[0068] Residual humidity percentage 60% (in the spinning/pressing/crushing stage)
[0069] Percentage of copper in the formulated solution 5%
[0070] These percentages of moisture in the fabric are obtained after applying the process of the present invention, and are percentages obtained by centrifugation of a 100% cotton fabric.
[0071] Antimicrobial Textile Production Process
[0072] In the following example was used 1000 g of natural fiber 100% cotton, 400 g of copper sulfate pentahydrate Cu 25%, 1200 ml of water and 25% ammonia, sufficient to dilute to 2000 ml mixture.
[0073] Preparation:
[0074] In 1200 ml of water, dissolve 400 g of copper sulfate pentahydrate at 25% Cu. Once the crystals are dissolved in water (if necessary, temperature can be applied to achieve full solubilization of solid and then let it cool), and then gauge up to 2000 mL with ammonia solution at 25%. The above mentioned formula is represented by the following chemical equilibrium:
[0000] CuSO 4 .5H 2 O+4NH 3 Cu(NH 3 ) 4 2+ +SO 4 2− +5H 2 O
[0075] Subsequently, the prepared solution is poured into a container of 4000 mL capacity, and then cotton fabric is soaked during 5 minutes ensuring it is completely wet. Then the fabric is centrifuged until it achieves 60% moisture content (calculated weight/weight). This 60% of moisture occluded represents a fabric or a matrix with a 3% of copper soaked.
[0076] As the fabric is centrifuged, the copper solution shall not migrate and homogeneous distribution is achieved.
[0077] It is allowed to evaporate or aerate up to 5% of the fabric moisture approximately (weight/weight). This is represented by the following chemical equilibrium:
[0000] Cu(NH 3 ) 4 2+ +SO 4 2− +H 2 O CuSO 4 .4NH 3 .H 2 O (pp)
[0078] Then temperature is applied to the fabric, according to the conditions of use desired for the matrix, one or both sides, this temperature should be about 60 to 120°, for a period of time that does not alter the physical qualities and fabric aesthetics to permeate, but to ensure the conversion of the reaction intermediate to alkaline copper sulphate occluded and fixed in the matrix.
[0079] This above mentioned formula is represented by the following chemical equilibrium:
[0000] 4CuSO 4 .4NH 3 .H 2 O+5H 2 O Cu 4 SO 4 (OH) 6(pp) +3SO 4 (NH 4 ) 2(soluble) +10NH 3(g)
[0080] After performing the above steps, the material used shall have become a raw matrix with alkaline copper sulphate occluded and fixed with antibacterial properties, which then should follow the common steps of washing, dyeing and standardized routine processes of this type of material.
[0081] Finally, with normal washing, any soluble residue is removed leaving only the alkaline copper sulphate in the fabric:
[0000]
EXAMPLE 2
Antibacterial Effect of the Compounds of Copper Oxide (I) Oxide, Copper Oxide (II), Copper Hydroxyphosphate (II), Copper Oxychloride (II) upon 12 Bacterial Strains
[0082] In this example, it was determined and compared the antibacterial activity of four chemical compounds. To this they were made 5 mm filter paper discs embedded with various concentrations of the compound oxide of copper (I), oxide copper (II), copper hydroxyphosphate (II), copper oxychloride (II) dissolved in DMSO (0 μg, 200 μg, 400 μg, 600 μg, 800 μg). The disks were deposited on a background lawn, which was performed as follows:
[0083] From a bacterial culture of 16 hours, with the strain of interest, it was performed a 1/30 dilution of the culture with fresh medium and incubated under stirring at 37° C. until reaching the exponential growth phase (D0600 nm 0.4-0.5). It was taken an aliquot of 100 μL of the culture in exponential phase, and deposited in 4 mL of Mueller-Hinton soft agar at 0.8% (previously melted and stabilized at 50° C.). The mixture was deposited on a Petri dish with 20 mL of Mueller-Hinton agar base. Once the agar was gelled, each of the discs with different amounts of the test compound were deposited on the background lawn, and incubated at 37° C. during 48 hairs.
[0084] Experiments were performed in triplicate in three independent events, using as negative control discs with the solvent DMSO alone, and as positive control were used commercial discs used with 30 μg of antibiotic Kanamycin (Km).
[0085] In Tables 1, 2, 3 and 4, you shall find the summary of the halo sizes of growth inhibition halo (mm) of 12 bacterial strains cultures when exposed to discs with different concentrations of compounds: copper oxide (I), copper oxide (II), copper hydroxyphosphate (II), copper oxychloride (II). In addition, each table gives details of inhibition halos of the controls.
[0086] The results indicate that the compounds oxide copper (I) oxide and copper (II) have no antibacterial activity on strains tested at the time evaluated at the concentrations used (Table 1 and Table 2). The copper hydroxyphosphate compound (II) has antibacterial activity only on the bacteria Staphylococcus epidermidis and Streptococcus pyogenes at the highest amount evaluated of 800 μg. Also, it presents growth inhibition activity on Acinetobacter baumanii in the range of 400 to 800 μg (Table 3). Meanwhile, copper oxychloride compound (II) has antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Escherichia coli and Acinetobacter baumannii (Table 4).
[0000]
TABLE 1
Determination of the antibacterial activity of the compound oxide of copper
(I)
Growth inhibition zone (naxn.)
Copper oxide compound (I)
Controls
Bacteria
200 μg
400 μg
600 μg
800 μg
Km
Disc DMSO
Staphylococcus
5.0
5.0
5.0
5.0
21 ± 2
5.0
aureus
ATCC25923
Staphylococcus
5.0
5.0
5.0
5.0
16 + 0.5
5.0
epidermidis
ATCC25923
Streptococcus
5.0
5.0
5.0
5.0
15 ± 0.8
5.0
pneumoniae
ATCC14325
Streptococcus
5.0
5.0
5.0
5.0
5
5.0
pyogenes
ATCC2367
Enterococcus
5.0
5.0
5.0
5.0
12.5 ± 1.2
5.0
faecium
ISP133/04
Enterococcus
5.0
5.0
5.0
5.0
10
5.0
faecalis
ATCC29212
Escherichia coli
5.0
5.0
5.0
5.0
18 ± 1.8
5.0
ATCC25922
Klebsiella
5.0
5.0
5.0
5.0
19 ± 0.3
5.0
pneumoniae
ATCC4352
Pseudomonas
5.0
5.0
5.0
5.0
7 ± 1.0
5.0
aeruginosa
PAOI
Acinetobacter
5.0
5.0
5.0
5.0
5.0
5.0
baumanii
UBP456
Citrobacter
5.0
5.0
5.0
5.0
19 ± 0.3
5.0
freundii
ISP1949/99
Enterobacter
5.0
5.0
5.0
5.0
14 + 0.5
5.0
aerogenes
ATCC13048
[0000]
TABLE 2
Determination of the antibacterial activity of the compound oxide of copper (II)
Growth inhibition zone (mi)
Copper oxide
Controls
compound (II)
Disc
Bacteria
200 μg
400 μg
600 μg
800 μg
Km
DMSO
Staphylococcus Aureus ATCC25923
5.0
5.0
5.0
5.0
20 ± 0.8
5.0
Staphylococcus epidennidis
5.0
5.0
5.0
5.0
14 + 0.7
5.0
ATCC25923
Streptococcus pneumoniae
5.0
5.0
5.0
5.0
12.5 ± 1.2
5.0
ATCC14325
Streptococcus pyogenes ATCC2367
5.0
5.0
5.0
5.0
5.0
5.0
Enterococcus faecium ISP133/04
5.0
5.0
5.0
5.0
9 ± 0.7
5.0
Enterococcus Faecalis ATCC29212
0.5
5.0
5.0
5.0
15 + 0.6
5.0
Escherichia coli ATCC25922
5.0
5.0
5.0
5.0
15 ± 0.2
5.0
Klebsiella pneumoniae ATCC4352
5.0
5.0
5.0
5.0
11 ± 1
5.0
Pseudomonas Aeruginosa PAOI
5.0
5.0
5.0
5.0
9 ± 0.7
5.0
Acinetobacter baumanii UDP456
5.0
5.0
5.0
5.0
5.0
5.0
Citrobacter freundii ISP1949/99
5.0
5.0
5.0
5.0
12 ± 0.5
5.0
Enterobacter aerogenes ATCC13048
5.0
5.0
5.0
5.0
15 ± 0.4
5.0
[0000]
TABLE 3
Determination of the antibacterial activity of copper hydroxyphosphate
compound (II)
Growth inhibition zone (mm)
Copper hydroxyphosphate
Controls
compound (II)
Disc
Bacteria
200 μg
400 μg
600 μg
800 μg
Km
DMSO
Staphylococcus aureus
5.0
5.0
5.0
5.0
15 ± 0.5
5.0
ATCC25923
Staphylococcus epidermidis
5.0
5.0
5.6 ± 0.5
6.3 ± 1.1
18 ± 0.7
5.0
ATCC25923
Streptococcus pneumoniae
5.0
5.0
5.0
5.0
11 ± 1
5.0
ATCC14325
Streptococcus pytogenes
5.0
5.0
5.0
8.6 ± 0.6
5.0
5.0
ATCC2367
Enterococcus faecium ISP133/04
5.0
5.0
5.0
5.0
9 ± 0.7
5.0
Enterococcus faecalis
5.0
5.0
5.0
5.0
15 ± 0.6
5.0
ATCC29212
Escherichia coli ATCC25S22
5.0
5.0
5.0
5.0
18 ± 0.7
5.0
Klebsiella pneumoniae
5.0
5.0
5.0
5.0
11 ± 1
5.0
ATCC4352
Pseudomonas Aeruginosa PAO1
5.0
5.0
5.0
5.0
7 + 0.7
5.0
Acinetobacter baumanii UDP456
5.0
8.6 ± 0.6
7.3 ± 2
7.6 ± 2.3
5.0
5.0
Citrobacter fraundii ISP1949/99
5.0
5.0
5.0
5.0
15 ± 0.5
5.0
Enterobacter aeroffenes
5.0
5.0
5.0
5.0
16 ± 0.4
5.0
ATCC13048
[0000]
TABLE 4
Determination of the antibacterial activity of copper oxychloride compound (II).
Growth inhibition zone <mm)
Compound
Controls
Fabric
Disc
Fabric
Bacteria
200 μg
400 μg
600 μg
800 μg
with
Km
DMSO
without
Staphylococcus aureus
6.0 ± 1.0
10.3 ± 0.6
11.7 ± 0.6
14.0 ± 1.0
29.0 ± 1.0
19.0
5.0
20.0
ATCC25923
Staphylococcus
12.0 ± 0.6
14.3 ± 0.6
13.7 ± 1.5
14.6 ± 0.6
30.3 ± 2.3
18.5 ± 3.5
5.0
20.0
epidermidis
ATCC25923
Straptococus
5.0 ± 1.0
8.0 ± 0.7
9.0 ± 1.0
11.0 ± 1.2
28.0 ± 0.4
11.5 ± 0.8
5.0
20.0
pneumoniae ATCC14325
Streptococcus
5.0 ± 1.0
6.0 ± 1.0
7.0 ± 1.2
8.0 ± 1.4
28.0 ± 0.4
5.0
5.0
20.0
pyogenes ATCC2367
Enterococcus faecium
6.0 ± 1.0
6.0 + 1.0
6.0 ± 1.0
6.0 ± 1.0
25.0
11.0
5.0
20.0
ISP133/04
Enterococcus faecalis
6.0 ± 1.0
6.0 ± 1.0
6.0 ± 1.0
6.0 ± 1.0
25.0
10.5 ± 0.2
5.0
20.0
ATCC29212
Escherichia coli
13.3 ± 1.4
13.0 ± 0.7
15.0 ± 0.7
13.3 ± 0.7
31.7 ± 2.1
20.0 ± 0.7
5.0
20.0
ATCC25S22
Klebsiella pneumoniae
7.3 ± 0.6
8.7 ± 0.6
9.7 ± 0.6
10.0
29.0 ± 1.0
5.0
5.0
20.0
ATCC4352
Pseudomonas
6.3 ± 1.5
6.7 ± 1.2
8.3 ± 0.6
3.3 ± 1.7
23.0 ± 1.0
7.0 ± 1.4
5.0
20.0
aeruginosa PAOI
Acinetobacter baumanii
11.7 ± 0.6
15.7 ± 0.6
17.0 ± 1.0
19.7 ± 0.6
32.0 ± 3.5
16.0 ± 1.4
5.0
20.0
UDP456
Citrobacter freundii
8.0 ± 1.0
10.7 ± 1.5
11.3 ± 0.6
11.3 ± 1.5
30.3 ± 1.2
19.0 ± 0.2
5.0
20.0
ISP1949/99
Enterobacter aerogenes
7.3 ± 1.5
3.7 ± 1.5
9.7 ± 0.6
9.7 ± 1.5
27.7 ± 0.6
19.0 ± 0.7
5.0
20.0
ATCC13048
EXAMPLE 3
Antibacterial Effect of a Thin Cloth Soaked with Compound Cu4SO 4 (OH) 6 (Alkaline Copper Sulfate)
[0087] In this example, the antimicrobial activity of the invention was determined by testing on sensidiscs. On order to do this, they were prepared 5 mm filter paper discs, embedded with various concentrations of compound Cu 4 SO 4 (OH) 6 (Alkaline Copper Sulfate) of the study dissolved in DMSO (0 μg, 200 μg, 400 μg, 600 μg, 800 μg). In addition, pieces of cloth of about 2×2 cm were prepared and embedded with the new product. Paper discs and fabric were deposited on a background lawn, which was performed as follows:
[0088] From a bacterial culture of 16 hours, with the strain of interest, it was performed a 1/30 dilution of the culture with fresh medium and incubated under stirring at 37° C. until reaching the exponential growth phase (D0600 nm 0.4-0.5). It was taken an aliquot of 100 μL of the culture in exponential phase, and deposited in 4 mL of Mueller-Hinton soft agar at 0.8% (previously melted and stabilized at 50° C.). The mixture was deposited on a Petri dish with 20 mL of Mueller-Hinton agar base. Once the agar was gelled, each of the discs with different amounts of the test compound were deposited on the background lawn, and incubated at 37° C. during 48 hours.
[0089] Experiments were performed in triplicate in independently, using as negative control discs with the solvent DMSO alone and cloth without the product of study. As positive control were used commercial discs used with 30 μg of antibiotic Kanamycin (Km). The results are presented in Table 5.
[0090] The compound Alkaline Copper Sulfate (OH) 6 presents antibacterial activity on all bacterial strains tested (Table 5). Finally, if the proposed invention is compared with the 4 chemical compounds of Example 2, copper oxide (I) cooper oxide (II), copper hydroxyphosphate (II), copper oxychloride (II), the product of invention exhibits a spectrum of antibacterial activity greater than the hydroxyphosphate copper compounds (II) and copper oxychloride (II).
[0000]
TABLE 5
Antibacterial activity of thin cloth soaked with the proposed compound (Alkaline
Copper Sulphate)
Growth inhibition zone (ram.)
Compound
Controls
Fabric
Fabric
with
Disc
without
Bacteria
200 μg
400 μg
600 μg
800 μg
comp
Km
DMSO
comp
Staphylococcus aureus
6.0 ± 1.0
10.3 ± 0.6
11.7 ± 0.6
14.0 ± 1.0
29.0 ± 1.0
19.0
5.0
20.0
ATCC25923
Staphylococcus
12.0 ± 0.6
14.3 ± 0.6
13.7 ± 1.5
14.6 ± 0.6
30.3 ± 2.3
18.5 ± 3.5
5.0
20.0
epidermidis
ATCC25923
Streptococcus
5.0 ± 1.0
8.0 ± 0.7
9.0 ± 1.0
11.0 ± 1.2
28.0 ± 0.4
11.5 ± 0.8
5.0
20.0
pneumonia ATCC14325
Streptococcus
5.0 ± 1.0
6.0 ± 1.0
7.0 ± 1.2
8.0 ± 1.4
28.0 ± 0.4
5.0
5.0
20.0
pyogenes ATCC2367
Enterococcus faecium
6.0 ± 1.0
6.0 ± 1.0
6.0 ± 1.0
6.0 ± 1.0
25.0
11.0
5.0
20.0
ISP133/04
Enterococcus faecalis
6.0 ± 1.0
6.0 ± 1.0
6.0 ± 1.0
6.0 ± 1.0
25.0
10.5 ± 0.2
5.0
20.0
ATCC29212
Escherichia coli
13.3 ± 1.4
13.0 ± 0.7
15.0 ± 0.7
13.3 ± 0.7
31.7 ± 2.1
20.0 ± 0.7
5.0
20.0
ATCC25922
Klebsiella pneumoniae
7.3 ± 0.6
8.7 ± 0.6
9.7 ± 0.6
10.0
29.0 ± 1.0
5.0
5.0
20.0
ATCC4352
Pseudomonas
6.3 ± 1.5
6.7 ± 1.2
8.3 ± 0.6
8.3 ± 1.7
23.0 ± 1.0
7.0 ± 1.4
5.0
20.0
aeruginosa PAOI
Acinetobacter
11.7 ± 0.6
15.7 ± 0.6
17.0 ± 1.0
19.7 ± 0.6
32.0 ± 3.5
16.0 + 1.4
5.0
20.0
baumannii UDP456
Citrobacter freundii
8.0 ± 1.0
10.7 ± 1.5
11.3 ± 0.6
11.3 ± 1.5
30.3 ± 1.2
19.0 ± 0.2
5.0
20.0
ISP1949/99
Enterobacter
7.3 ± 1.5
9.7 ± 1.5
9.7 ± 0.6
9.7 ± 1.5
27.7 ± 0.6
19.0 ± 0.7
5.0
20.0
aerogenes
ATCC13048
EXAMPLE 4
Electronic Scanning Microscopy for a Matrix of Fabric with Antimicrobial Activity
[0091] In this example, the fabric structure was compared with the compound of alkaline copper occluded, fixed and embedded and the control fabric (no compound) using electronic scanning microscopy. The analysis was performed in the JSM-5410 Scanning Microscopic equipment and it was used Vantage 1.4.2 software to analyze the results. The samples were coated with Au—Pd bath.
[0092] By comparing the images of the fabric with the embedded compound ( FIG. 1 a ) and the control fabric ( FIG. 1 b ), it is noted that the fabric with the compound has noticeably brighter areas than the control fabric, which correspond to parts of the structure with higher molecular weight due to the presence of the compound. Additionally, it is noted that the alkaline copper solution applied to the fabric is impregnated homogeneously within it, leaving some insoluble residues. By observing the the fabric impregnated with the compound at a higher magnification ( FIG. 2 b ), it is observed the presence of copper incorporated into the fiber.
[0093] The analysis of the composition of the control fabric determined the presence of oxygen, aluminum, silicon atoms, finding further traces of magnesium, potassium and titanium ( FIG. 3 a ). Meanwhile, the analysis of the fabric impregnated with the compound shows the presence of a high copper content, the presence of oxygen, aluminum and traces of calcium ( FIG. 3 b ). Traces of water may be due to calcium in the applied solution.
EXAMPLE 5
Quantitative Analysis of the Antibacterial Activity of the Matrix (Thick Cloth) Occluded and Fixed with Alkaline Copper Sulphate
[0094] In this example, the antibacterial activity was quantitatively established of a thick or heavy cloth, which was treated by the process of the present invention for fixing and occlusion of alkaline copper sulfate, upon bacterial strains of Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25322, from tests determining the minimum inhibitory concentration (MIC). From a bacterial culture of 16 hours, with the strain of interest, it was performed a 1/30 dilution of the culture with fresh medium and incubated under stirring at 37° C. until reaching the exponential growth phase (D0600 nm 0.4-0.5). It was taken an aliquot of 100 μL of the culture in exponential phase, and deposited in 4 mL of Mueller-Hinton soft agar at 0.8% (previously melted and stabilized at 50° C.). The mixture was deposited on a Petri dish with 20 mL of Mueller-Hinton agar base. Once the agar was gelled, then an E-test generated with a concentration gradient of the study compound was deposited on the background lawn, and incubated at 37° C. during 48 hours.
[0095] Experiments were performed in triplicate in three independent events, using as negative control discs with dimethyl sulfoxide solvent (DMSO) alone and as positive control were used commercial discs used with 30 μg of antibiotic Kanamycin (Km).
[0096] The results of the minimum inhibitory concentration (Table 6) indicate that compound of alkaline copper sulphate fixed and occluded in a heavy fabric presents antibacterial activity, which is reflected in a minimum inhibitory concentration of 200 ug/mL for bacteria Staphylococcus aureus ATCC 25923 and 300 ug/mL for Escherichia coli ATCC 25922).
[0000]
TABLE 6
Minimum Inhibitory Concentration of copper solution
occluded and fixed in a thick cloth
Bacteria
MIC
DMSO
Kanamycin
Staphylococcus aureus
200 μg/mL
−
+
ATCC 25923
Escherichia coli
300 μg/mL
−
+
ATCC 25922
EXAMPLE 6
Qualitative Determination of the Antibacterial Activity of the Matrix (Thick Cloth) Occluded and Fixed with Alkaline Copper Sulphate
[0097] This example determined qualitatively the antibacterial effect of the copper solution proposed, embedded in a matrix of thick fabric which was prepared following the procedure of the present invention. Pieces of cloth of about 2×2 cm were prepared and embedded with the product and then were deposited on a background lawn of 12 different bacteria strains.
[0098] In order to do this, it was prepared a bacterial culture of 16 hours, with the strain of interest, it was performed a 1/30 dilution of the culture with fresh medium and incubated under stirring at 37° C. until reaching the exponential growth phase (D0600 nm 0.4-0.5). It was taken an aliquot of 100 μL of the culture in exponential phase, and deposited in 4 mL of Mueller-Hinton soft agar at 0.8% (previously melted and stabilized at 50° C.). The mixture was deposited on a Petri dish with 20 mL of Mueller-Hinton agar base. Once the agar was gelled, each of the discs with different amounts of the test compound were deposited on the background lawn, and incubated at 37° C. during 48 hours.
[0099] Experiments were performed in triplicate in independently, using as negative control discs with the solvent DMSO alone and cloth without the product of study. As positive control were used commercial discs used with 30 μg of antibiotic Kanamycin (Km).
[0100] Experiments were performed in triplicate in three independent events. The results obtained (Table 7) indicate that the proposed solution of copper mounted on a thicker fabric matrix presents antibacterial activity on almost all bacterial strains tested.
[0000]
TABLE 7
Antibacterial activity of matrix (thick cloth) occluded
and fixed with alkaline copper sulphate
Growth inhibition zone
Fabric with
Fabric
Bacteria
comp
without
Km
Staphylococcus aureus ATCC25923
28.3 ± 0.7
20
18.0 ± 0.5
Staphylococcus epidermidis
29.3 ± 1.7
20
24.0 ± 1.0
ATCC2S923
Streptococcus pneumoniae
26.3 ± 0.6
20
10.0 ± 0.2
ATCC14325
Streptococcus pyogenes ATCC2367
26.0 ± 1.0
20
6.0 ± 1.0
Enterococcus faecium ISP133/04
23.3 + 0.6
20
11.0 ± 0.8
Enterococcus faecalis ATCC29212
25.6 ± 0.7
20
14.0 ± 1.0
Escherichia coli ATCC25922
24.6 ± 0.6
20
19.0 ± 0.5
Klebsiella pneumoniae ATCC4352
27.0 ± 0.6
20
18.0 ± 1.0
Pseudomonas aeruginosa PAOI
23.0 ± 0.7
20
7.0 ± 0.5
Acinetobacter baumanii UPP4 56
26.3 ± 0.3
20
5.0
Citrobacter freundii ISP1949/99
23.3 ± 0.3
20
17.0 + 0.3
Enterobacter aerogenes ATCC13048
24.0 ± 1.0
20
12.0 ± 0.5
[0101] From the above examples, it can be indicated that the maximum and minimum concentrations for inclusion into the matrix and required for said matrix having antimicrobial effect, can be in the range of about 0.1% to about 5% of active copper (in relation to the weight of the matrix), which is relevant, because it has activity with a low concentration of copper. Higher concentrations of active copper would be unnecessary to achieve the proposed antibacterial effect.
EXAMPLE 7
Conversation of the Antimicrobial Activity of the Matrixes in Thick and Thin Fabrics Containing Alkaline Copper Sulphate Occluded and Fixed, after Washing
[0102] This example established qualitatively the antibacterial activity of matrixes in thin fabric (Fabric 1) and thick fabric (Fabric 2) embedded with the product, following the procedure described herein, and after subjected to washing. In order to do this, there were taken pieces of 2×2 cm from both fabrics, cut and washed for 2 hours with stirring using commercial laundry detergent. Subsequently, the washed fabric pieces which have the new product are dried in an oven at 40° C. for 3 hours and placed on the background lawn. In order to generate the background lawn, it was prepared a bacterial culture of 16 hours, with the strain of interest, it was performed a 1/30 dilution of the culture with fresh medium and incubated under stirring at 37° C. until reaching the exponential growth phase (D0600 nm 0.4-0.5). It was taken an aliquot of 100 μL of the culture in exponential phase, and deposited in 4 mL of Mueller-Hinton soft agar at 0.8% (previously melted and stabilized at 50° C.). The mature was deposited on a Petri dish with 20 mL of Mueller-Hinton agar base. Once the agar was gelled, each of the discs with the different amounts of the compound were deposited on the background lawn, and incubated at 37° C. during 48 hours.
[0103] Experiments were performed using as negative control pieces of both fabrics without the product of study and undergoing the process before mentioned. Additionally, as positive control, they were used commercial discs used with 30 μg of antibiotic Kanamycin (Km).
[0104] Experiments were performed in triplicate and in three independent events. From the treated plates, it was measured the zone of inhibition generated by each control and fabrics embedded with the proposed compound, which is summarized in Table 7. It was noted that both the thin fabric (Fabric 1) and the thick fabric (Fabric 2) impregnated with copper proposed solution, maintain their antibacterial activity on the two strains evaluated after being washed with a commercial detergent.
[0000]
TABLE 8
Determination of the inhibition halos of thin fabric (Fabric 1) and thick
fabric (Fabric 2) with alkaline copper sulphate occluded and fixed.
Growth inhibition zone
Fabric 1
Fabric 1
Fabric 2
Fabric 2
Bacteria
with comp
without comp
with comp
without comp
Km
Staphylococcus aureus
27 ± 1.7
20
26.0 ± 1.0
20
18.0 ± 1.4
ATCC25923
Escherichia coli
24 ± 1.7
20
16.3 ± 1.2
2.0
20.6 ± 0.6
ATCC25922
FIGURES DESCRIPTION
[0105] FIG. 1 .—Electronic Scanning Microscopy of the fabric with the compound and the control fabric. In a), an image shows the control fabric increased to 160 μm and in b), the picture is taken at the same occluded fixed fabric impregnated with the compound but in an increased size.
[0106] FIG. 2 .—Petrographies of electronic scanning electron microscopy of control fabric and fabric impregnated with the antibacterial compound increased at 16 μt. In a), it is observed the control material at the increase described. In b), it is shown the image of the occluded material, fixed, and impregnated with the proposed compound by the inventor. It is noted the presence of copper incorporation into the proposed fabric.
[0107] FIG. 3 .—Graphic of the scanning microscopy of the control fabric and the fabric with the proposed compound incorporated. The analysis peaks represent the presence and abundance of atoms analyzed and specified on it. The presence of copper in the fabric is verified. | The invention relates to an impregnable matrix of plant, animal or synthetic origin or mixtures of same in different proportions, containing an antimicrobial compound uniformly distributed throughout the whole composition, in which the compound is a compound of a transition metal, particularly Cu4S04(OH)e. The application also relates to the method for impregnating the matrix with a compound, comprising steps of (a) absorbing or impregnating the antimicrobial compound; (b) centrifuging or pressing or crushing; (c) air drying; and (d) binding and obtaining the active principle. The invention further relates to the use of the method for the preparation of a matrix having antimicrobial properties and to the use of the matrix in the preparation of solid supports or solid materials for cosmetic, pharmaceutical, medical or veterinary use. | 3 |
This is a continuation of application Ser. No. 888,061, filed 7/22/86, and now abandoned.
BACKGROUND OF THE INVENTION
The use of hydrophilic polymers in the controlled release of medicaments is known. A problem with such polymers is, however, that large quantities of the hydrophilic material is often required in order to effect proper control of drug release. This is a particularly severe problem when the unit dose of the medicament is large (e.g. above about 60% by wt).
The use of anionic surfactants in solid pharmaceutical compositions is also known. Until recently, however, the presence of such surfactants was designed to facilitate fast and total release of the medicament from the composition (see, for example, Japanese Kokai 7320778 and A.A. Kassem etal, J. Drug Research, 1974, 6, 95).
U.S. Pat. No. 4,540,566 and P.B. Daly et al, Int. J. Pharm. 18, 201 (1984) describes a controlled release composition containing chlorpheniramine maleate, a cellulose ether and an anionic surfactant. However, the composition is a simple mixture and does not provide any particular advantages.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide controlled release pharmaceutical compositions with improved controlled release characteristics.
It is another object of the present invention to provide controlled release pharmaceutical compositions wherein the drug, which is the acid addition salt or quarternary ammonium of an organic base, is complexed with an anionic surfactant and distributed in a hydrophilic polymer, whereby the control of drug release is considerably facilitated and made more flexible.
Other objects and advantages of the present invention will be apparent from a further reading of the specification and of the appended claims.
With the above and other objects in view, the present invention mainly comprises a complex of an acid addition salt or quarternary ammonium salt of an organic base drug and a pharmaceutically acceptable anionic surfactant distributed in a hydrophilic polymer matrix.
It has been found that the contacting of the acid addition salt or quarternary ammonium salt of the basic drug with the surfacant results in complex formation between the drug and the surfactant, with substantially all of the drug and surfactant (at least 70% by weight and up to 100% by weight of the drug) being complexed. In this form, the complex distributed in the hydrophilic polymer matrix provides excellent controlled release of the drug when injested.
Preferably the composition is in unit dosage form and administered by the oral route, especially as a tablet or as a capsule containing solid granules.
It has been found that, when the drug is an acid addition salt of an organic base or a quaternary ammonium salt complexed with the anionic surfactant an enhanced level of control over drug release is obtained. This enhanced effect is achieved by the complex formation between the acid addition salt (of the organic base) or the quaternary ammonium salt thereof and the anionic surfactant, the complex formed being water soluble at all biological pHs, especially between pH 1.5 to 7.0.
The combined use of the hydrophilic polymer and the anionic surfactant complex allows considerable flexibility in the control of drug release from compositions according to this invention. The rate of drug release, which is independent of pH, may be altered simply by modifying the polymer/surfactant in the composition, the release of a drug at any point within the digestive tract (and at any pH within the tract, 1.5 to 7.0) may be controlled).
Furthermore, the use of the anionic surfactant complex in combination with the hydrophilic polymer, allows the quantity of the polymer in the composition to be reduced without detriment to the control of the drug release. This is particularly advantageous when the composition contains a large quantity of drug. The combination (polymer/surfactant) also facilitates the compression (and shaping) of the present pharmaceutical composition into unit dosae forms.
The anionic surfactants which are effective in the present composition include alkali metal sulphates, such as sodium or potassium dodecylsulphate, sodium octadecysulphate, and, which is preferred, alkali metal sulphonates, such as the alkali metal salts of benzene sulphonates, naphthalene sulphonates and, especially, dialkysulphosuccinates. An alkali metal, especially sodium, salt of dioctylsodium sulphosuccinate is not absorbed upon oral administration.
The hydrophilic polymer may be any of the hydrophilic polymers employed in pharmaceutical compositions, especially controlled release pharmaceutical compositions. Examples include carboxyalkylcellulose, alginic acid derivatives and carboxypolymethylenes (e.g. Carbopol, Trademark). Preferably, however, the hydrophilic polymer is a water soluble, non-ionic cellulose ether, especially a hydroxyalkyl cellulose ether. Examples include hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and, which is preferred, hydroxypropyl. cellulose, and which is preferred, hydroxypropylmethyl cellulose.
Most preferably, the hydrophilic polymer, especially the cellulose ether, has a number average molecular weight of at least 50,000, especially at least 75,000.
The amount of the hydrophilic polymer and the anionic surfactant in the present composition, as well as the ratio of these materials, will depend, inter alia, on the rate of the drug release required. Preferably, the combined wt % of polymer and surfactant in the present composition is between 10% and 60%, especially between 10% and 50%. The preferred ratio (of polymer to surfactant) is between 50 to 1 and 1 to 2, especially between 30 to 1 and 1 to 1. Preferably each unit dose of the present composition contains between 1mg and 30mg, especially between 2mg and 20mg of the anionic surfactant.
In the case of dioctyl sodium sulphosuccinate, which at high levels acts as a laxative, the use of such low levels of the surfactant represents a distinct advantage.
The drug may be either any acid addition salt (inorganic or organic) of an organic base or any quaternary ammonium salt thereof. Preferably the drug is an acid addition salt of an organic amine. Examples of suitable drugs are:
(a) Analgesic agents; e.g. salts of morphine, codeine, ethyl morphine, dihydrocodeine, hydromorphone, phenazocine, pentazocine, buprenorphine, meptazinol, flupirtine,
(b) Antiinflammatory agents; e.g. salts of aminopyrine,
(c) Antihistamines; e.g. salts of clemastine, mepyramine, diphenlhydramine, dexchlorpheniramine,
(d) Topical anesthestics; e.g. salts of lidocaine, procaine,
(e) Vasodilators; e.g. salts of papaverine, diltiazem, nicardipine,
(f) Antitussives and expectorants, e.g. salts of isprotenerol, dextromethorphan,
(g) Antihypertensives; e.g. salts of clonidine,
(h) Antineoplastic agents; e.g. salts of doxorubicin,
(i) Bronchodilators; e.g. ipratropium bromide, and salts of albuterol (salbutamol).
(j) Antiarrythmic agents; e.g. salts of verpamil, quinidine,
(k) Antibiotics or fungicides; e.g. salts of tetracyclines, neomycine,
(l) Chemotherapeutic agents; e.g. salts of clotrimazole,
(m) Oral antiseptics; e.g. dequalinium chloride, and salts of chlordexidine, ethacridine,
(n) Anticholinergics; e.g. salts of scopolamine,
(o) Muscle relaxtants; e.g. salts of baclofen, cyclobenzaprine,
(p) Drugs for treatment of ulcers; e.g. salts of cimetidine, ranitidine,
(q) Antimetics; e.g. salts of metoclopramide,
(r) Antimalarials, e.g. salts of quinine,
(s) Antipsychotics; e.g. salts of perphenazine.
Particularly preferred drugs for use in the present composition are acid addition salts of metoclopramide, codeine, ethylmorphine, morphine, dextromethorphan, quinidine, quinine, dihydrocodeine, hydromorphone, perphenazine, diltiazem, meptazinol and flupirtine, especially metoclopramide hydrochloride, codeine phosphate, ethylmorphine, hydrochloride, morphine sulphate, dextromethorphan hydrobromide, quinidine polygalacturonate, quinine sulphate, dihydrocodeine tartrate, hydromorphone hydrochloride, perphenazine hydrochloride, diltiazem hydrochloride, meptazinol hydrochloride and flupirtine maleate.
These drugs can be used either singly or as a mixture of two or more. The amount of drug to be blended in a solid dosage unit will generally be enough to maintain a therapeutic level of the drug in the bloodstream for a predetermined period (preferably 8 hours or longer).
In addition to the constituents discussed above, the present controlled release pharmaceutical composition may also contain known excipients, such as lubricants, binders, vehicles, colouring agents, taste controlling agents and odour controlling agents, that are employed to improve the appearance, odour or taste of pharmaceutical preparations.
In order to facilitate the preparation of a unit dosage form from the present composition there is provided, in a further aspect of the present invention, a process for the preparation of a solid, controlled release, pharmaceutical unit dosage form comprising granulating a composition comprising a drug, a hydrophilic polymer and an antionic surfactant and, optionally, compressing and shaping the granules wherein the drug is either an acid addition salt of an organic base or a quaternary ammonium salt.
In a particularly preferred embodiment of the present process, the anionic surfactant is dissolved in a C 1 -C 6 alkyl alcohol, especially a C 2 -C 4 alkyl alcohol, or in an aqueous alcoholic solution and the hydrophilic polymer is then mixed with the surfactant solution to form a homogeneous mixture. Granulation of this mixture is followed by the addition of the drug to the granules, wherein the drug and surfactant complex.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples are given to further illustrate the present invention. The scope of the invention is not, however, meant to be limited to the specific details of the examples:
EXAMPLE 1
Dioctyl sodium sulphosuccinate (4.0 gm) was dissolved in isopropanol (25 ml). Hydroxpropylmethyl cellulose (90 gm, Metolose 90SH 4000) was mixed with the sulphoscuccinate solution until the mixture was homogeneous, the formation of granules being avoided. The mixtures was then granulated and sieved through a 16 mesh screen. The granules were left to dry in the air until the isopropanol had evaporated.
Quinidine polygalacturonate (288.75 gm) and lactose (32.63 gm) were then added and the whole was mixed thoroughly, resulting in complex formation between the quinidine salt and the dioctyl sodium sulphosuccinate. Magnesium stearate (0.42 gm) and talc (4.2 gm) were then added and mixing was continued until a homogeneous mixture was obtained. Finally, the mixture was regranulated and sieved through a 16 mesh screen.
The granules obtained were compressed and shaped into one thousand 420mg tablets, each containing 288.75mg of quinidine polygalacturonate.
EXAMPLE 2
The procedure of Example 1 was repeated except that the amounts of materials used were as follows:
______________________________________Quinidine polygalacturonate 412.5 gmIron oxide red 0.5 gmHydroxypropylmethyl cellulose 92 gmDioctyl sodium sulphosuccinate 4 gmTalc 5.8 gmMagnesium Stearate 0.58 gmLactose 65 gm______________________________________
This produced 1,000 tablets weighing 580mg and containing 412.5mg of quinidine polygalacturonate.
EXAMPLE 3
Metoclopramide hydrochloride (15 gm was mixed with hydroxpropylmethyl cellulose (18 gm) and lactose (80.75 gm). The mixture was granulated with a solution of dioctyl sodium sulphosuccinate (7.5 gm) in isopropanol. The granules were then dried and lubricated, with talc (2.5 gm) and magnesium stearate (1.25 gm).
The granules obtained were compressed and shaped into 1000 tablets each weighing 125mg. and each containing 15mg of metoclopramide hydrochloride.
EXAMPLE 4
The procedure of Example 3 was followed except that hydroxypropylmethyl cellulose (30 gm) and dioctyl sodium sulphosuccinate (5 gm) was used. The amount of lactose was reduced to 71.25 gm. This produced 1000 tablets weighing 125mg and containing 15mg of metoclopramide hydrochloride.
EXAMPLE 5
(Comparative)
The procedure of Example 3 was followed except that no dioctyl sodium sulphosuccinate was used and the amount of hydroxypropylmethyl cellulose was increased to 42 gm. The amount of lactose was reduced to 64.25 gm.
EXAMPLE 6
The procedure of Example 3 was repeated with the following ingredients,
______________________________________Metoclopramide hydrochloride 15 gmHydroxpropylmethyl cellulose 30 gmDioctyl sodium sulphosuccinate 12.5 gmTalc 2.5 gmMagnesium stearate 1.25 gmLactose 63.75 gm______________________________________
This produced 1000 tablets weighing 125mg and containing 15mg of metoclopramide hydrochloride.
EXAMPLES 7-10
The procedure of Example 6 was followed except that the amount of dioctyl sodium sulphosuccinate was varied as follows:
______________________________________ Amount of Dioctyl Sodium Sulphosuccinate______________________________________Example 7 6.25 gmExample 8 5 gmExample 9 4 gmExample 10 2 gm______________________________________
In each case, the amount of lactose was increased, as required, in order to give tablets the same weight as produced in Example 6.
EXAMPLE 11
(Comparative)
The procedure of Example 6 was repeated except that no dioctyl sodium sulphosuccinate was employed and the amount of lactose was increased by 12.5 gm.
EXAMPLE 12
The procedure of Example 1 was repeated with the following ingredients,
______________________________________Morphine sulphate 30 gmHydroxyethyl cellulose 20 gmDioctyl sodium sulphosuccinate 7.5 gmTalc 2.5 gmMagnesium stearate 1.25 gmLactose 63.75 gm______________________________________
This produced 1000 tablets weighing 125mg, each containing 30mg of morphine sulphate.
EXAMPLE 13
The procedure of Example 1 was repeated with the following ingredients,
______________________________________Codeine phosphate 30 gmCarboxymethyl cellulose 30 gmDioctyl sodium sulphosuccinate 7.5 gm(Ultrawet 40DS)Talc 2.5 gmMagnesium stearate 1.5 gmLactose 53.75 gm______________________________________
This produced 1000 tablets weighing 125mg, each containing 30mg of codeine phosphate.
EXAMPLES 14 AND 15
The procedure of Example 4 was followed except that the dioctyl sodium sulphosuccinate was replaced by sodium dodecylsulphate (Example 14) and sodium dodecylbenzene sulphonate (Example 15).
Dissolution Studies
The rate of release of various compositions according to this invention were investigated using he USP Paddle Method (Propharmacopoeia no. 79) at 50rpm in 500 ml. on a pH gradient: pH 1.5 for the first hour, pH 4.5 for the second hour and pH 6.9 thereafter. The temperature was 37° C. samples were taken every hour.
Using this method, the dissolution rate of tablets prepared by Examples 3 to 11 above were determined. Results are given in the Tables below.
TABLE 1______________________________________Effect of varying the proportion of the hydroxypropylMethylcellulose (HPMC) and the dioctyl sodium sulphosuccinate(DOS) on dissolution rates of metoclopramide HCl.Example 3 Example 4 Example 5HPMC, 18 mg HPMC, 30 mg HPMC, 42 mgDOS, 7.5 mg DOS, 5 mg DOS, 0 mg______________________________________1 hr 31% 33% 32%2 hr 42% 43% 46%3 hr 53% 51% 56%4 hr 63% 61% 61%6 hr 71% 69% 70%8 hr 83% 80% 82%______________________________________
TABLE 2__________________________________________________________________________Effect of changes in the amount of dioctyl sodium sulphosuccinate(DOS) with constant hydroxpropylmethylcellulose HPMC/ondissolution rates of metoclopramide HClExample 11 Example 10 Example 9 Example 8 Example 7 Example 6HPMC, 30 mg HPMC, 30 mg HPMC, 30 mg HPMC, 30 mg HPMC, 30 mg HPMC, 30 mgDOS, 0 mg DOS, 2 mg DOS, 4 mg DOS, 5 mg DOS, 6.25 mg DOS 12.5 mg__________________________________________________________________________1 hr 41% 38% 36% 33% 26% 18%2 hr 62% 55% 46% 43% 38% 25%3 hr 69% 62% 54% 51% 49% 32%4 hr 75% 70% 62% 61% 56% 38%5 hr 91% 83% 77% 69% 66% 51%6 hr 97% 93% 89% 80% 75% 63%__________________________________________________________________________
TABLE 3______________________________________The effect of pH on the dissolution rate of metoclopramide HCltablets prepared as described in Example 4pH gradient pH 1.5 pH 4.5 pH 6.9______________________________________1 hr 33% 35% 30% 30%2 hr 43% 43% 44% 44%3 hr 51% 53% 50% 51%4 hr 61% 61% 56% 58%5 hr 69% 71% 67% 69%6 hr 80% 82% 79% 84%______________________________________
TABLE 4______________________________________Dissolution of guinidine polygalaturonate tablets prepared asdescribed in Example 2 HPMC, 92 mg DOS, 4 mg______________________________________ 1 hr 51.1 2 hr 61.4 3 hr 69.3 4 hr 75.1 5 hr 82.6 6 hr 86.6______________________________________
Clinical Studies
A comparative single dose pharmacokinetic study of two quinidine polygalaturonate preparations, namely quinidine polygalacturonate 412.5mg tablets prepared as described in Example 2 and controlled release quinidine polygalacturonate 412.5mg capsules (Cardioquine, Trade Mark) was carried out on 4 volunteers. Results are given in Table 5.
TABLE 5______________________________________Time TABLET CAPSULE(hr) Mean Plasma Level (ng/ml Mean Plasma Level (ng/ml______________________________________0.17 0 00.33 0.08 00.50 0.24 0.0040.75 0.41 0.091.0 0.42 0.211.5 0.46 0.332.0 0.53 0.412.5 0.57 0.483.0 0.57 0.504.0 0.62 0.555.0 0.72 0.536.0 0.67 0.558.0 0.59 0.4910.0 0.54 0.4012.0 0.43 0.3224.0 0.23 0.17______________________________________
A randomised, crossover, single dose comparative pharmacokinetic study of two quinidine polygalacturonate preparations, namely quinidine polygalacturonate 412.5mg tablets, prepared as described in Example 2, and controlled release quinidine polygalacturonate 412.5mg capsules (Cardioquine, Trade Mark), was carried out on 12 volunteers. Results are given in Tables 6, 7 and 8.
TABLE 6______________________________________Time TABLET CAPSULE(hr) Mean Plasma Level (ng/ml Mean Plasma Level (ng/ml______________________________________0.25 0.042 0.0060.5 0.22 0.0140.75 0.37 0.171.0 0.47 0.311.5 0.55 0.482.0 0.64 0.642.5 0.66 0.773.0 0.69 0.84.0 0.71 0.835.0 0.67 0.776.0 0.62 0.698.0 0.51 0.5510.0 0.43 0.4512.0 0.35 0.3624.0 0.13 0.1430.0 0.08 0.09______________________________________
TABLE 7______________________________________TABLETS (EXAMPLE 2) T 1/2T C AUC AUC ELIM-MAX MAX 0-30 0-INF IN. MRT______________________________________Subject 1 2 0.82 10.84 11.98 8.7 13.03Subject 2 3 1.05 12.39 12.95 6.26 10.55Subject 3 1 0.54 6.9 8.85 14.15 19.55Subject 4 2.5 0.94 9.2 10.17 8.92 12.68Subject 5 2 0.64 8.46 9.47 9.67 13.59Subject 6 4 0.81 11.7 14.68 12.92 18.94Subject 7 6 0.89 9.85 10.05 4.89 8.99Subject 8 3 0.88 12.83 15.22 10.72 16.25Subject 9 4 0.95 9.38 9.75 6.05 9.97Subject 10 5 0.65 6.74 7.16 6.81 11.25Subject 11 3 0.59 7.47 7.93 7.18 10.6Subject 12 2 0.82 11.61 12.95 8.84 13.51Average 3.13 0.8 9.78 10.93 8.76 13.24Standard 1.42 0.16 2.12 2.6 2.8 3.42DeviationSubject 1 4 0.89 14.24 16.22 9.44 15Subject 2 4 1.04 12.91 15.01 10.96 15.23Subject 3 2.5 0.72 6.99 7.27 6.16 10.12Subject 4 5 0.77 10.82 12.89 11.17 16.68Subject 5 4 0.76 7.98 8.33 6.32 10.2Subject 6 3 0.67 9.4 9.97 6.56 11.57Subject 7 4 0.92 9.77 10.77 8.92 12.75Subject 8 5 0.87 11.13 12.24 8.24 13.17Subject 9 5 1.21 12.77 13.44 7.05 10.43Subject 10 4 0.66 7.04 7.9 9.94 13.36Subject 11 3 0.68 6.54 7.13 8.48 11.41Subject 12 2 1.03 14.17 15.16 8.75 13.63Average 3.79 0.85 10.31 11.41 8.5 12.8Standard 0.99 0.17 2.81 3.33 1.72 2.13Deviation______________________________________
While the invention has been described with respect to particular drugs, aionic surfactants and hydrophilic polymers, it is apparent that variations and modifications of the invention can be made without departing from the spirit or scope of the invention. | A solid, controlled release pharmaceutical composition is provided with enhanced levels of control over drug release. The composition comprises an acid addition salt or a quarternary ammonium salt of an organic base drug complexed with an anionic surfactant and distributed in a matrix of a hydrophilic polymer. The complex formation between the drug which is preferably an acid addition salt of an organic an organic amine, and the surfactant, which is preferably a sulphosuccinate, distributed in the hydrophilic polymer matrix, which is preferably a water soluble hydroxyalkylcelulose ether results in a composition with excellent controlled released characteristics. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to and claims priority benefits from U.S. Provisional Patent Application Ser. No. 60/800,816 filed on May 16, 2006, entitled LEAD-FREE PRIMARY EXPLOSIVE COMPOSITION AND METHOD OF PREPARATION. The '816 application is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to explosives, and in particular to primary explosives that are free of lead.
BACKGROUND OF THE INVENTION
[0003] Explosive materials have a wide variety of applications. Primary explosives are sensitive explosive materials that are used, in relatively small quantities, to initiate a secondary or main explosive charge. Primary explosives should be sufficiently sensitive to be detonated reliably but not so sensitive as to be exceedingly dangerous to handle. Moreover, primary explosives should have sufficient thermal stability so as to not decompose on extended storage or temperature fluctuation. Many primary explosives in current use contain lead, with the most well-known example being lead azide. These lead-containing explosives are undesirable from an environmental standpoint, since their use and manufacture can contribute to or cause lead contamination.
[0004] Thus, there is a need in the art for lead-free explosive materials and in particular for lead-free primary explosives. Certain lead-free primary explosives have been proposed. For instance, nitrotetrazole-based primary explosives have been proposed in U.S. Pat. Nos. 4,093,623 and 4,094,879, as well as in U.S. Patent App. Pub. No. 2006/0030715. For a variety of reasons, some of these proposed compounds have failed to serve as commercially viable substitutes for lead-containing primary explosives, while others exhibit characteristics that make them undesirable for at least some commercial applications. For example, U.S. Patent App. Pub. No. 2006/0030715 discloses certain nitrotetrazole complexes (including copper(II) complexes) which form a crystalline structure that is difficult to work with from a handling and ordinance loading standpoint.
SUMMARY OF THE INVENTION
[0005] Certain embodiments of the present subject matter are directed to a compound and material that may be used as a lead-free primary explosive, and methods for preparing such compound and material.
[0006] A first aspect of the present subject matter is the compound copper(I) nitrotetrazolate.
[0007] Another aspect of the present subject matter is a compound prepared by the following steps: providing cuprous salt; providing water; providing 5-nitrotetrazolate salt; combining the cuprous salt, water and 5-nitrotetrazolate salt to form a mixture; and heating the mixture.
[0008] Another aspect of the present subject matter is a compound prepared by the following steps: providing cuprous chloride; providing water; providing sodium 5-nitrotetrazolate; combining the cuprous chloride, water and sodium 5-nitrotetrazolate to form a mixture; and heating the mixture.
[0009] Yet another aspect of the present subject matter is a method of preparing copper(I) nitrotetrazolate which consists of the steps of: providing cuprous salt; providing water; providing 5-nitrotetrazolate salt; combining the cuprous salt, water and 5-nitrotetrazolate salt to form a mixture; and heating the mixture.
[0010] Yet another aspect of the present subject matter is a method of preparing copper(I) nitrotetrazolate which consists of the steps of: providing cuprous chloride; providing water; providing sodium 5-nitrotetrazolate; combining the cuprous chloride, water and sodium 5-nitrotetrazolate to form a mixture; and heating the mixture.
[0011] A further aspect of the present subject matter is a method of preparing a lead-free primary explosive, comprising the steps of: providing cuprous salt; providing water; providing 5-nitrotetrazolate salt; combining the cuprous salt, water and 5-nitrotetrazolate salt to form a mixture; and heating the mixture.
[0012] A further aspect of the present subject matter is a method of preparing a lead-free primary explosive, comprising the steps of: providing cuprous chloride; providing water; providing sodium 5-nitrotetrazolate; combining the cuprous chloride, water and sodium 5-nitrotetrazolate to form a mixture; and heating the mixture.
[0013] Another aspect of the present subject matter is the reaction product of a cuprous salt and a 5-nitrotetrazolate salt in water.
[0014] Yet a further aspect of the present subject matter is the reaction product of cuprous chloride and sodium 5-nitrotetrazolate in water.
[0015] Another aspect of the present subject matter is a product prepared by the following steps: providing cuprous chloride; providing a solvent (which may be water); providing sodium 5-nitrotetrazolate; combining the cuprous chloride, solvent, and sodium 5-nitrotetrazolate to form a mixture; and heating the mixture.
[0016] Another aspect of the present subject matter is a product prepared by the following steps: providing cuprous chloride; providing a solvent (which may be water); providing sodium 5-nitrotetrazolate; providing hydrochloric acid; combining the cuprous chloride, solvent, sodium 5-nitrotetrazolate, and hydrochloric acid to form a mixture; and heating the mixture.
[0017] Another aspect of the present subject matter is a compound prepared by the following steps: providing cuprous salt; providing water; providing 5-nitrotetrazolate salt; providing hydrochloric acid; combining the cuprous salt, water, 5-nitrotetrazolate salt, and hydrochloric acid to form a mixture; and heating the mixture.
[0018] Yet another aspect of the present subject matter is a method of preparing copper(I) nitrotetrazolate which consists of the steps of: providing cuprous salt; providing water; providing 5-nitrotetrazolate salt; providing hydrochloric acid; combining the cuprous salt, water, 5-nitrotetrazolate salt, and hydrochloric acid to form a mixture; and heating the mixture.
[0019] Another aspect of the present subject matter is a method of preparing copper(I) nitrotetrazolate which consists of the steps of: providing copper(I) ions; providing 5-nitrotetrazolate ions; providing a solvent; combining the copper(I) ions, 5-nitrotetrazolate ions, and solvent to form a mixture; and heating the mixture. Another aspect of the present subject matter is a compound prepared by the above steps.
[0020] The foregoing description of aspects of the present subject matter has been presented for purposes of illustration and description. Other aspects of the subject matter will be apparent to persons familiar with the present subject matter.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0021] FIG. 1 shows the results of a differential scanning calorimetry (DSC) analysis on a material prepared according to the present techniques.
[0022] FIG. 2 shows the results of a Fourier Transform Infrared Spectroscopy (FTIR) analysis on a material prepared according to the present techniques.
[0023] FIG. 3 shows the results of a DSC analysis on a material prepared according to the present techniques.
[0024] FIG. 4 shows the results of a FTIR analysis on a material prepared according to the present techniques.
[0025] FIG. 5 is a Scanning Electron Microscopy (SEM) photomicrograph of a material prepared according to the present techniques.
[0026] FIG. 6 shows the results of a DSC analysis on a material prepared according to the present techniques.
[0027] FIG. 7 shows the results of a FTIR analysis on a material prepared according to the present techniques.
[0028] FIG. 8 shows the results of a Thermogravimetric Analysis (TGA) analysis on a material prepared according to the present techniques, as compared to silver and lead azide.
[0029] FIG. 9 shows the results of an energy dispersive spectroscopy analysis on a material prepared according to the present techniques.
[0030] FIG. 10 shows the spectra resulting from an ultraviolet spectrophotometry analysis on a material prepared according to the present techniques.
[0031] FIG. 11 shows the peak table for the ultraviolet spectrophotometry spectra shown in FIG. 10 .
[0032] FIG. 12 shows the results of a TGA analysis on a material prepared according to the present techniques, as compared to silver and lead azide.
[0033] FIG. 13 shows the results of a DSC analysis on a material prepared according to the present techniques.
[0034] FIG. 14 shows an optical photomicrograph of a material prepared according to the present techniques.
DETAILED DESCRIPTION OF THE INVENTION
[0035] One aspect of the present subject matter is the compound copper(I) nitrotetrazolate. Copper(I) nitrotetrazolate has two possible isomers, both of which are contemplated herein. The isomers are depicted below:
[0000]
[0000] Alternatively, isomer (I) is contemplated. Alternatively, isomer (II) is contemplated. As yet another alternative, a mixture of isomers (I) and (II) is contemplated. Applicants note that USAARADC Technical Report ARBRL-TR-02371 (Schroeder and Henry) suggests that 1-substituted tetrazoles are more stable than 2-substituted tetrazoles. Also contemplated is any mixture which contains copper(I) nitrotetrazolate in a significant quantity (e.g. greater than about 1 weight percent, or alternatively, greater than about 5 weight percent).
[0036] Methods for preparing copper(I) nitrotetrazolate are contemplated in the present application. Copper(I) nitrotetrazolate may be prepared by reacting a copper(I) salt (for example, cuprous chloride) and a 5-nitrotetrazolate salt (for example, sodium 5-nitrotetrazolate) in a solvent (for example, water). Any suitable copper(I) salt, or combination of copper(I) salts, may be employed. Suitable copper(I) salts include, but are not limited to, cuprous chloride and cuprous bromide. Alternatively, cuprous chloride may be used as the copper(I) salt. Likewise, any suitable 5-nitrotetrazolate salt, or combination of 5-nitrotetrazolate salts, may be employed. Suitable 5-nitrotetrazolate salts include, but are not limited to, sodium 5-nitrotetrazolate and potassium 5-nitrotetrazolate. Likewise, any suitable solvent, or combination of solvents, may be employed. Suitable solvents include, but are not limited to, water, dimethyl sulfoxide (DMSO), as well as other polar organic solvents. Optionally, an acid (for example, hydrochloric acid) may be added to the reaction described above. Suitable acids include, but are not limited to, nitric acid, sulfuric acid, perchloric acid, and acetic acid. Alternatively, hydrochloric acid may be used.
[0037] It will be understood that ionic versions of the salts referred to above may be employed in the preparation of copper(I) nitrotetrazolate. In other words, copper(I) nitrotetrazolate may be prepared by a reaction in which copper(I) ions and 5-nitrotetrazolate ions are combined to form copper(I) nitrotetrazolate. By way of non-limiting example, a copper(I) salt may be reacted with 5-nitrotetrazolate ions to form copper(I)nitrotetrazolate.
[0038] The components may be reacted under conditions suitable to synthesize copper(I) nitrotetrazolate. Alternatively, the components may be reacted by mixing them together and then heating the mixture. The mixture may be heated in the temperature range of about 70° C. to about 150° C., alternatively in the temperature range of about 80° C. to about 130° C., alternatively to about 100° C. As yet another alternative, a reflux condenser may be employed, and the mixture may be heated to the reflux point. The duration of the heating or refluxing step may be a duration that is greater than about 5 minutes, alternatively greater than about 10 minutes, alternatively greater than about 20 minutes, alternatively from about 10 minutes to about 2 hours, alternatively from about 10 minutes to about 1 hour, alternatively about 15 minutes. Alternatively, the heating or refluxing step may be of sufficient duration such that the reaction goes to completion.
[0039] Regarding quantities of the components employed, 5-nitrotetrazolate may be supplied in a molar ratio of about 0.5 moles to about 4 moles 5-nitrotetrazolate per mole of copper(I). Alternatively, 5-nitrotetrazolate may be supplied in a molar ratio of about 0.8 moles to about 1.5 moles 5-nitrotetrazolate per mole of copper(I). Alternatively, 5-nitrotetrazolate may be supplied in a molar ratio of about 1 mole to about 1.2 moles 5-nitrotetrazolate per mole of copper(I). For example, sodium 5-nitrotetrazolate (NaNT) may be supplied in a molar ratio of about 0.5 moles to about 4 moles NaNT per mole of cuprous chloride, alternatively about 0.8 moles to about 1.5 moles NaNT per mole of cuprous chloride, alternatively about 1 mole to about 1.2 moles NaNT per mole of cuprous chloride.
[0040] A solvent may be supplied in an amount that is suitable to effectuate the reaction between 5-nitrotetrazolate and copper(I). For example, water (or other solvent) may be supplied in an amount that is suitable to effectuate the reaction between a 5-nitrotetrazolate salt and a copper(I) salt. As a more specific example, water (or other solvent) may be supplied in an amount that is suitable to effectuate the reaction between NaNT and cuprous chloride. Alternatively, water (or other solvent) may be supplied such that the concentration of 5-nitrotetrazolate salt in the reaction mixture would be in the range of about 0.01 M to about 2 M, alternatively in the range of about 0.05 M to about 0.5 M, alternatively about 0.3 M. For example, water may be supplied such that the concentration of NaNT in the reaction mixture would be in the range of about 0.01 M to about 2 M, alternatively in the range of about 0.05 M to about 0.5 M, alternatively about 0.3 M.
[0041] The addition of an acid to the reaction can improve the thermal stability of the resulting product. Thus an acid may be added to the reaction in a quantity that improves the thermal stability of the resulting product. Alternatively, the acid may be added to the reaction mixture in a molar ratio of about 0.1 moles to about 5 moles acid per mole of 5-nitrotetrazolate, alternatively in a molar ratio of about 0.5 moles to about 3 moles acid per mole of 5-nitrotetrazolate, alternatively in a molar ratio of about 1 mole acid per 1 mole 5-nitrotetrazolate. The acid added to the reaction may be hydrochloric acid, for example. Alternatively, nitric, sulfuric, perchloric, or acetic acid, or mixtures of foregoing (including hydrochloric acid), may be added. These exemplary acids are typically supplied in aqueous solution.
[0042] The reaction components may be combined in any order or sequence suitable to effectuate the reaction. By way of non-limiting example, the reaction of 5-nitrotetrazolate salt and copper(I) salt may be carried out by adding an aqueous solution of 5-nitrotetrazolate salt to an aqueous suspension of copper(I) salt, or vice versa. If such a reaction methodology is employed, the concentration of 5-nitrotetrazolate salt in the aqueous solution may be in the range of about 0.05 M to about 3 M, alternatively in the range of about 0.1 M to about 1 M, alternatively about 0.2 M to about 0.3 M, alternatively 0.28 M. The concentration of copper(I) salt in the aqueous suspension may be in the range of about 0.005 g/ml to about 2 g/ml, alternatively in the range of about 0.01 g/ml to about 1 g/ml, alternatively about 0.1 g/ml, alternatively about 0.02 g/ml. If the optional acid is employed, such acid may be added to either the 5-nitrotetrazolate salt solution or the copper(I) salt suspension prior to combination, or it may be added to the reaction mixture after combination (or it could be added in separate addition steps at more than one point). By way of non-limiting example, if acid is added to the 5-nitrotetrazolate salt solution prior to combination with the copper(I) salt suspension, it may be added in a molar ratio of about 0.1 moles to about 5 moles acid per mole of 5-nitrotetrazolate, alternatively in a molar ratio of about 0.5 moles to about 3 moles acid per mole of 5-nitrotetrazolate, alternatively in a molar ratio of about 1 mole acid per 1 mole 5-nitrotetrazolate.
[0043] The copper(I)nitrotetrazolate formed by the reaction of cuprous salt (for example, cuprous chloride), water and 5-nitrotetrazolate salt (for example, sodium 5-nitrotetrazolate) may be a precipitate. The precipitate may be separated by a suitable method known to those of skill in the art. Alternatively, the precipitate may be separated by filtration. As yet another alternative, the precipitate may be separated using a flotation technique. It may be desirable to separate finer or lighter precipitate particles from coarser or heavier precipitate particles (for example, the coarser or heavier particles may be desirable from the standpoint of easy handling and loading). A flotation technique may be employed to achieve such a separation, as may other techniques known to those of skill in the art. Alternatively, the fine particles may be removed by careful decanting. Alternatively, the precipitate (which may, for example, be a dark brown precipitate) is collected over filter paper.
[0044] The precipitate formed by the reaction of cuprous salt (for example, cuprous chloride), water and 5-nitrotetrazolate salt (for example, sodium 5-nitrotetrazolate) may be washed. For example, the product may be washed either a single time or multiple times with water. Alternatively, the product may be washed either a single time or multiple times with alcohol, for example, isopropanol. Alternatively, the product may be washed in multiple steps and in any order with both water and alcohol. For example, the product may be washed sequentially with water and then isopropanol. The product may then be dried. For example, the product may be air dried. Alternatively the product may be dried in an oven at 65 to 80° C.
[0045] The present application also contemplates products made by the methods described above. In other words, the present application contemplates products made by reacting cuprous salt (for example, cuprous chloride) and 5-nitrotetrazolate salt (for example, sodium 5-nitrotetrazolate) in water, under the conditions and component quantities described above. The present application also contemplates the reaction product of cuprous salt (for example, cuprous chloride), water and 5-nitrotetrazolate salt (for example, sodium 5-nitrotetrazolate) as described above.
[0046] The products contemplated and made by the methods of the present application (in at least some aspects of the present subject matter, copper(I) nitrotetrazolate) are free of lead and have been found suitable for use as explosives and, in particular, as primary explosives. Thus, the present application also contemplates methods for preparing compounds suitable for use as primary explosives, and explosive devices employing such compounds. Benefits include low cost, ease of preparation and low toxicity waste streams and health benefits associated with low lead materials in both military and commercial applications.
[0047] The products contemplated and made by the methods of the present application (including copper(I) nitrotetrazolate) exhibit a crystalline structure that is suitable for loading and handling. A non-limiting example of such a crystalline structure is shown in FIG. 5 (Scanning Electron Microscopy (SEM) photomicrograph).
EXAMPLES
[0048] The following examples demonstrate the preparation and characterization of a material as taught herein.
Example 1
[0049] Copper(I) nitrotetrazolate was prepared as follows. Cuprous chloride (0.10 g) was suspended in 5 mL of water in a 25 mL Erlenmeyer flask under a nitrogen atmosphere. The mixture was heated to 90° C. on a hot plate with stirring. Sodium 5-nitrotetrazolate dihydrate (0.178 g) was dissolved in 5 mL of water and added to the flask using 2 mL of water to transfer. The solution was stirred at elevated temperature for 5 minutes at which point a small amount of brownish solid had formed. The mixture was stirred with heating for an additional 9 minutes and then the heating was suspended. The resulting brown solid was filtered over Millipore HVLP (0.45 μm) filter paper, washed twice with water, three times with isopropanol and then dried in a convection oven at 70° C.
[0050] The results of a differential scanning calorimetry (DSC) analysis on the solid are shown in FIG. 1 . The results of a Fourier Transform Infrared Spectroscopy (FTIR) analysis on the solid are shown in FIG. 2 .
Example 2
[0051] Copper(I) nitrotetrazolate was prepared as follows. Cuprous chloride (0.90 g, 9.01 mmol) was suspended in 20 mL of water in a 100 mL round bottom flask containing an oval magnetic stir bar. The flask was placed in an oil bath and controlled stirring was started at a rate of 600 RPM. Sodium 5-nitrotetrazolate dihydrate (2.08 g, 1.2 eq.) was dissolved in 20 mL of water and added to the flask. A reflux condenser was placed on the flask and the solution was heated to reflux (approximately 100° C.). The initially green solution turned brown during heating and a brown precipitate formed at or near reflux temperature. The solution was maintained at reflux for about 50 minutes. The flask was removed from the oil bath. The fine, light brown particles were removed by careful decanting and the remaining dark brown material was filtered over Whatman #1 filter paper. The dark brown product was washed three times with water and then three times with isopropanol and afforded a clear filtrate. The crystalline product (1.12 g) was air dried overnight.
[0052] The results of a differential scanning calorimetry (DSC) analysis on the crystalline product are shown in FIG. 3 . The results of a Fourier Transform Infrared Spectroscopy (FTIR) analysis on the crystalline product are shown in FIG. 4 . FIG. 5 is a Scanning Electron Microscopy (SEM) photomicrograph of the crystalline product.
[0053] The crystalline copper(I) nitrotetrazolate product was further dried in a convection oven at 65° C. for 4 hours and then stored in a dessicator before being subjected to several tests known to persons familiar with the field of technology. The results of these tests are as follows.
Friction Sensitivity Testing
[0054] Friction sensitivity testing was performed using a small scale Julius Peters BAM tester with a maximum load weight of 2075 g. Lead azide (a common lead-containing primary explosive) was also tested for purposes of comparison.
[0000]
Copper(I) nitrotetrazolate
Low Fire Level: 10 g
No Fire Level: 0 g
Lead azide (RD1333)
Low Fire Level: 10 g
No Fire Level: 0 g
Impact Sensitivity Testing
[0055] Impact sensitivity was tested using a ball drop instrument designed to meet the specifications of NATO AOP-7 registry number US/High Explosives/201.01.002. Lead azide was also tested for purposes of comparison.
[0000]
Copper(I) nitrotetrazolate
0.040 ± 0.010 J
Lead azide (RD1333)
0.050 ± 0.004 J
Strong Confinement/Dent Block Testing
[0056] The test material and lead azide (RD1333) were both run (3 units per powder, 6 total) utilizing the following procedure for side by side comparison. ZPP (24 mg) was pressed into a header (P/N 2-300062) having a 1 ohm 0.0022″ stablohm bridgwire at 10 kpsi. The materials were loaded into stainless steel cans having a 7 mil wall thickness and pressed at 10 kpsi. The headers were pressed into intimate contact with the output charges and sealed. The units were fired into 1″ aluminum blocks and the resulting dents recorded.
[0000]
Copper(I)
Avg. Dent: 0.037″
Avg. Function Time: 46us
nitrotetrazolate
Lead azide (RD1333)
Avg. Dent: 0.033″
Avg. Function Time: 45us
[0057] As is evident from the above comparative testing, the material prepared according to the present techniques performed in a manner that is at least equivalent to lead azide.
Example 3
[0058] Copper(I) nitrotetrazolate was prepared as follows. Cuprous chloride (0.901 g, 9.01 mmol) was suspended in 20 mL of water in a 100 mL round bottom flask containing an oval magnetic stir bar. Sodium 5-nitrotetrazolate dihydrate (2.08 g, 1.2 eq.) was dissolved in 20 mL of water and added to the flask. A reflux condenser was placed on the flask and the solution was heated to reflux in a preheated (125° C.) oil bath. The stirring rate was maintained at 300 RPM. The initially dull green solution turned brown during heating and a brown precipitate formed at or near reflux temperature. The solution was maintained at reflux temperature for about 45 minutes. The flask was removed from the oil bath and the solids were allowed to settle. The flask was placed in a ring stand and suspended above a 1 L crystallizing dish. A glass tube (⅛″) was connected to a DI water source using rubber tubing and the tube was inserted into the solids to the bottom the flask. DI water was introduced into the flask at such a flow rate as to suspend fine particles of the precipitate. These were decanted into the crystallizing dish by continuous DI water flow. Larger particles of the precipitate remained at the bottom of the round bottom flask. The remaining larger particles (a dark brown material) were filtered over Whatman #1 filter paper. The product was transferred with water and then washed three times with isopropanol and afforded a clear filtrate. The crystalline copper(I) nitrotetrazolate product (0.87 g) was air dried overnight before being subjected to several analyses known to persons familiar with the field of technology. The results of these analyses are as follows.
[0059] The results of a differential scanning calorimetry (DSC) analysis on the crystalline product are shown in FIG. 6 . The results of a Fourier Transform Infrared Spectroscopy (FTIR) analysis on the crystalline product are shown in FIG. 7 .
[0060] A Thermogravimetric Analysis (TGA) was conducted on samples of the crystalline product, as well as on comparative samples of colloidal lead azide and silver azide. The results of this analysis are shown in FIG. 8 . The TGA analysis demonstrates the thermal stability of the crystalline product.
[0061] Analysis by energy dispersive spectroscopy (EDS) was conducted on the crystalline product. The results of this semi-quantitative analysis are shown in FIG. 9 and as follows:
[0000]
Element
Line
keV
Kratio
Wt %
At %
ChiSquare
Na
KA1
1.041
0.0002
0.08
0.06
2.91
K
KA1
3.313
0.0000
0.00
0.00
0.00
Cu
KA1
8.046
0.2773
35.01
9.32
1.07
Cl
KA1
2.622
0.0035
0.45
0.22
1.31
C
KA1
0.277
0.1613
63.31
89.19
12.95
O
KA1
0.523
0.0018
1.14
1.21
2.17
Total
100.00
100.00
7.61
[0000]
Gross
BKG
Overlap
Net
Element
Line
(cps)
(cps)
(cps)
(cps)
Na
KA1
9.104
4.602
4.115
0.411
K
KA1
13.177
13.438
0.000
0.000
Cu
KA1
180.268
9.876
0.000
169.765
Cl
KA1
19.222
12.700
0.000
6.661
C
KA1
34.941
1.550
0.000
33.025
O
KA1
3.428
2.274
0.000
1.174
[0000]
Det
Z
A
F
Tot
Element
Line
Eff
Corr
Corr
Corr
Corr
Modes
Na
KA1
0.619
1.057
3.667
1.000
3.878
Elmnt.
K
KA1
0.871
1.127
1.049
0.995
1.177
Elmnt.
Cu
KA1
0.993
1.276
0.989
1.000
1.262
Elmnt.
Cl
KA1
0.812
1.125
1.144
0.999
1.285
Elmnt.
C
KA1
0.052
0.912
4.304
1.000
3.924
Elmnt.
O
KA1
0.185
0.958
6.779
0.999
6.494
Elmnt.
[0062] The results of the energy dispersive spectroscopy analysis show that the crystalline product does not contain significant amounts of sodium, which would have indicated the presence of a copper complex (such as Na 2 Cu(NT) 4 (H 2 O) 2 disclosed in U.S. Application Pub. No. 2006/0030715).
[0063] Analysis by ultraviolet spectrophotometry was conducted on the crystalline product. A weighted sample of the product was digested in 1N sodium hydroxide and filtered to remove the copper oxide. The rust color of this residue indicated that it was copper(I) oxide and not other copper oxides. The absorbance of the appropriately diluted filtrate was determined at 256 nanometers and the 5-nitrotetrazolate content determined using the following previously developed relationship:
[0064] Where:
Y=5243.4X−0.0098 Y=absorbance at 256 nanometers X=concentration of sodium 5-nitrotetrazolate (moles/liter)
The UV spectrophotometry data is provided in FIGS. 10 and 11 . The results demonstrate a 5-nitrotetrazolate content of 62.25% which compares well with the theoretical value of 64.22% for a copper to 5-nitrotetrazolate ratio of one-to-one.
[0068] The results of the above analyses demonstrate that the crystalline product is copper(I) nitrotetrazolate. In particular, the results of the energy dispersive spectroscopy analysis show that the crystalline product does not contain sodium or chlorine, while the results of the UV spectrophotometry demonstrate that copper (I) is present and that the copper and nitrotetrazole are present in a one-to-one ratio.
Example 4
[0069] Copper(I) nitrotetrazolate was prepared as follows. Cuprous chloride (0.45 g) was suspended in 20 mL of water in a 100 mL round bottom flask containing an oval magnetic stir bar. The flask was placed in a glycerin bath and controlled stirring was started at a rate of 300 RPM. Sodium 5-nitrotetrazolate dihydrate (0.98 g) was dissolved in 20 mL of water and added to the flask. A reflux condenser was placed on the flask and the solution was heated to reflux (approximately 100° C.). The initially green solution turned brown during heating and a brown precipitate formed at or near reflux temperature. The solution was maintained at reflux for about 34 minutes. The flask was removed from the glycerin bath. The fines were separated by decantation and water addition. The remaining precipitate was filtered over Whatman #1 filter paper. The dark brown product was washed three times with water and then three times with isopropanol and afforded a clear filtrate. The crystalline product was dried in an oven at 70° C.
[0070] Density testing was performed on the crystalline product. Density determined by helium pyncnometry was: 2.81±0.005 g/cc.
Example 5
[0071] Copper(I) nitrotetrazolate was prepared as follows. Cuprous chloride (0.454 g) was suspended in 5 mL of water in a 100 mL round bottom flask containing an oval magnetic stir bar under an argon atmosphere. The flask was placed in a glycerin bath and controlled stirring was started at a rate of 450 RPM. Sodium 5-nitrotetrazolate dihydrate (1.007 g) was dissolved in 16 mL of water and 6 mL of 1N HCl was added. The sodium 5-nitrotetrazolate solution was added to the flask. A reflux condenser was placed on the flask and the solution was heated to reflux (125° C. bath temperature). The initially light green solution turned rust brown during heating and a brown precipitate formed at or near reflux temperature. The solution was maintained at reflux for about 16 minutes. The flask was removed from the glycerin bath. The precipitate was collected over Whatman #1 filter paper. The dark brown product was washed five times with water and then three times with isopropanol and afforded a light green filtrate. The crystalline product was dried in an oven at 80° C. The yield of small rust crystals was 0.631 g.
[0072] A Thermal Gravimetric Analysis (TGA) was conducted on a sample of the crystalline product, as well as on comparative samples of colloidal lead azide and silver azide. The results of this analysis are shown in FIG. 12 . The TGA analysis demonstrates the thermal stability of the copper(I) nitrotetrazolate and that it is superior to lead azide. The unusually low value for lead azide is undoubtedly due to the oxidation of lead azide to lead oxide via small impurities of oxygen present in the argon purge gas. This phenomenon is not seen in the copper(I) nitrotetrazolate or silver azide samples. The difference in TGA results for examples 3 and 5 are a direct result of the preparation of these materials. Example 5 employs dilute aqueous hydrochloric acid whereas example 3 uses only water in the preparation.
[0073] The results of a differential scanning calorimetry (DSC) analysis on the crystalline product are shown in FIG. 13 . FIG. 14 is an optical photomicrograph (80× magnification) of the product.
Example 6
[0074] A product is prepared as follows. Cuprous chloride (0.50 g) is suspended in water in a flask containing a magnetic stir bar. The flask is placed in a glycerin bath and controlled stirring is started. Sodium 5-nitrotetrazolate dihydrate (0.60 g) is dissolved in water and added to the flask. A reflux condenser is placed on the flask and the solution is heated to reflux (approximately 100° C.). The initially green solution turns brown during heating and a brown precipitate forms at or near reflux temperature. The solution is maintained at reflux for 15 minutes. The flask is removed from the glycerin bath. The fine particles are removed by careful decanting. The dark brown precipitate is washed multiple times with isopropanol. The product is then air dried.
Example 7
[0075] A product is prepared as follows. Cuprous chloride (0.83 g) is suspended in water. Sodium 5-nitrotetrazolate dihydrate (1.00 g) is dissolved in water. Hydrochloric acid (1N) is added to the sodium 5-nitrotetrazolate solution at a vol/vol ratio of 1:3. The sodium 5-nitrotetrazolate solution is added to the aqueous solution of cuprous chloride. A reflux condenser is placed on the flask and the solution is heated to reflux (approximately 100° C.). The initially green solution turns brown during heating and a brown precipitate forms at or near reflux temperature. The solution is maintained at reflux for about 30 minutes. The dark brown precipitate is collected over filter paper. The product is washed sequentially with water and isopropanol and then dried in an oven at 80° C.
Example 8
[0076] A product is prepared as follows. An aqueous solution of sodium 5-nitrotetrazolate (NaNT) and a suspension of cuprous chloride are combined such that the resulting molar ratio is about 1.2 moles NaNT per mole of cuprous chloride. The combined aqueous mixture is heated to reflux (approximately 100° C.). The initially green solution turns brown during heating and a brown precipitate forms at or near reflux temperature. The solution is maintained at reflux for up to 2 hours. The fine particles are removed by careful decanting. The dark brown product is washed multiple times with isopropanol. The product is dried in an oven at 70° C.
Example 9
[0077] A product is prepared as follows. An aqueous solution of sodium 5-nitrotetrazolate (NaNT) and a suspension of cuprous chloride are combined such that the resulting molar ratio is about 1 mole NaNT per mole of cuprous chloride. The combined aqueous mixture is heated to 90° C. The initially green solution turns brown during heating and a brown precipitate forms. The solution is heated for up to 2 hours. Upon removal from heat, the fine, light brown particles are removed, leaving a dark brown product. The dark brown precipitate is collected over filter paper. The dark brown product is washed sequentially with water and isopropanol. The product is then dried in an oven at 65° C.
Example 10
[0078] A product is prepared as follows. Cuprous chloride (1.00 g) is suspended in water under an argon atmosphere. Sodium 5-nitrotetrazolate dihydrate (3.48 g) is dissolved in water. Nitric acid (1N) is added to the sodium 5-nitrotetrazolate solution at a vol/vol ratio of 1:5. The sodium 5-nitrotetrazolate solution is added to the aqueous solution of cuprous chloride. The combined solution is heated to approximately 105° C. The initially green solution turns brown during heating and a brown precipitate forms. The solution is maintained at 105° C. for about 60 minutes. The flask is removed from heat. The fine particles are removed by careful decanting. The product is washed sequentially with water and isopropanol and then dried in an oven at 80° C.
Example 11
[0079] A product is prepared as follows. An aqueous solution of sodium 5-nitrotetrazolate (NaNT) and a suspension of cuprous chloride are combined such that the resulting molar ratio is about 0.85 moles NaNT per mole of cuprous chloride. The combined aqueous mixture is heated to 95° C. The initially green solution turns brown during heating and a brown precipitate forms. The solution is heated for up to 2 hours. Upon removal from heat, the fine, light brown particles are removed, leaving a dark brown product. The dark brown precipitate is collected over filter paper. The dark brown product is washed sequentially with water and isopropanol. The product is then dried in an oven at 80° C.
Example 12
[0080] A product is prepared as follows. Cuprous chloride (0.99 g) is suspended in water. Sodium 5-nitrotetrazolate dihydrate (1.73 g) is dissolved in water. The sodium 5-nitrotetrazolate solution is added to the flask containing the aqueous solution of cuprous chloride. The combined aqueous solution is heated to 100° C. The initially green solution turns brown during heating and a brown precipitate forms. The solution is heated for about 30 min. The resultant product is collected, washed with isopropanol, and dried.
Example 13
[0081] A product is prepared as follows. Cuprous chloride (0.50 g) is suspended in water in a flask containing a magnetic stir bar. The flask is placed in a glycerin bath and controlled stirring is started. Sodium 5-nitrotetrazolate dihydrate (0.93 g) is dissolved in water. Perchloric acid (0.1N) is added to the sodium 5-nitrotetrazolate solution at a vol/vol ratio of 1:5. The sodium 5-nitrotetrazolate solution is added to the flask containing the aqueous solution of cuprous chloride. The combined aqueous solution is heated to 105° C. The initially green solution turns brown during heating and a brown precipitate forms. The solution is heated for about 15 min. The flask is removed from the glycerin bath. The fine particles are removed by careful decanting. The dark brown precipitate is then collected over filter paper. The dark brown precipitate is washed multiple times with isopropanol. The product is then air dried.
Example 14
[0082] A product is prepared as follows. An aqueous solution of sodium 5-nitrotetrazolate (NaNT) and a suspension of cuprous chloride are combined such that the resulting molar ratio is about 0.8 moles NaNT per mole of cuprous chloride. The combined aqueous mixture is heated to approximately 110° C. The initially green solution turns brown during heating and a brown precipitate forms. The solution is heated for up to 2 hours. The resultant fine particles are removed by careful decanting. The resultant dark brown precipitate is collected over filter paper. The dark brown precipitate is washed sequentially with water and isopropanol and then dried in an oven at 80° C.
Example 15
[0083] A product is prepared as follows. Cuprous chloride (0.99 g) is suspended in water. Sodium 5-nitrotetrazolate dihydrate (1.73 g) is dissolved in water. Hydrochloric acid (1N) is added to the sodium 5-nitrotetrazolate solution at a vol/vol ratio of 1:4. The sodium 5-nitrotetrazolate solution is added to the aqueous solution of cuprous chloride. The solution is heated to approximately 100° C. The solution is heated for about 30 minutes. The resultant product is collected, washed with isopropanol, and dried.
Example 16
[0084] A product is prepared as follows. Cuprous chloride (0.50 g) is suspended in water in a flask containing a magnetic stir bar. The flask is placed in a glycerin bath and controlled stirring is started. Sodium 5-nitrotetrazolate dihydrate (1.05 g) is dissolved in water. Sulfuric acid (0.2N) is added to the sodium 5-nitrotetrazolate solution at a vol/vol ratio of 1:2. The sodium 5-nitrotetrazolate solution is added to the flask containing the aqueous solution of cuprous chloride. The solution is heated to approximately 85° C. The solution is heated for about 45 minutes. The flask is removed from the glycerin bath. The resulting product is collected, washed with isopropanol, and dried.
Example 17
[0085] A product is prepared as follows. An aqueous solution of sodium 5-nitrotetrazolate (NaNT) and a suspension of cuprous chloride are combined such that the resulting molar ratio is about 0.75 moles NaNT per mole of cuprous chloride. The combined aqueous mixture is heated to 125° C. for 25 min. Upon removal from heat, the fine, light brown particles are removed, leaving a dark brown product. The dark brown precipitate is collected over filter paper. The dark brown product is washed multiple times with isopropanol. The product is then dried in an oven at 80° C.
Example 18
[0086] A product is prepared as follows. An aqueous solution of sodium 5-nitrotetrazolate (NaNT) and a suspension of cuprous chloride are combined such that the resulting molar ratio is about 2 moles NaNT per mole of cuprous chloride. The combined aqueous mixture is heated to 115° C. for 90 min. Upon removal from heat, the dark brown precipitate is then collected over filter paper. The dark brown product is washed sequentially with water and isopropanol. The product is then dried in an oven at 80° C.
Example 19
[0087] A product is prepared as follows. Cuprous chloride (0.50 g) is suspended in water in a flask containing a magnetic stir bar under an argon atmosphere. The flask is placed in a glycerin bath and controlled stirring is started. Sodium 5-nitrotetrazolate dihydrate (1.04 g) is dissolved in water. Hydrochloric acid (0.1N) is added to the sodium 5-nitrotetrazolate solution at a vol/vol ratio of 1:1. The sodium 5-nitrotetrazolate solution is added to the flask containing the aqueous solution of cuprous chloride. The combined aqueous solution is heated to 90° C. for about 35 min. The flask is removed from the glycerin bath. The fine particles are removed by careful decanting and the dark brown precipitate is then collected over filter paper. The dark brown precipitate is washed multiple times with isopropanol. The product is then air dried.
[0088] All patents, test procedures, and other documents cited herein are fully incorporated by reference to the extent such disclosure is not inconsistent with the subject matter described and for all jurisdictions in which such incorporation is permitted.
[0089] While the present subject matter has been described and illustrated by reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the subject matter lends itself to many different variations not illustrated herein. For these reasons, then, reference should be made solely to the appended claims for purposes of determining the true scope of the present invention.
[0090] Although the appendant claims have single appendencies in accordance with U.S. patent practice, each of the features in any of the appendant claims can be combined with each of the features of other appendant claims or the main claim. | Embodiments of the present subject matter provide a compound and material that may be used as a lead-free primary explosive. An embodiment of the present subject matter provides the compound copper(I) nitrotetrazolate. Certain embodiments of the present subject matter provide methods for preparing lead-free primary explosives. The method includes: providing cuprous salt; providing water; providing 5-nitrotetrazolate salt; combining the cuprous salt, water and 5-nitrotetrazolate salt to form a mixture; and heating the mixture. The method may also include providing cuprous chloride and providing sodium 5-nitrotetrazolate. Certain embodiments of the present subject matter also provide methods for preparing copper(I) nitrotetrazolate. The method includes: providing cuprous salt; providing water; providing 5-nitrotetrazolate salt; combining the cuprous salt, water and 5-nitrotetrazolate salt to form a mixture; and heating the mixture. The method may also include providing cuprous chloride and providing sodium 5-nitrotetrazolate. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is related to a co-pending application entitled "PICK-FINDING MECHANISM WITH CREEPING SPEED", Ser. No. 313,128, filed concurrently herewith.
FIELD OF THE INVENTION
This invention relates to an apparatus provided in the drive train between a weaving machine and a shed-forming machine for effecting pick finding and slow-speed operation and, more particularly, to such an apparatus having an auxiliary motor, a coupling, and a return spring which urges the coupling into engagement.
BACKGROUND OF THE INVENTION
A shed-forming machine is, for pick finding, rotated slowly in a conventional manner by an auxiliary motor through a shiftable reduction gearing. The basic element of each pick-finding mechanism which is arranged between a weaving and a shed-forming machine is a single-tooth claw coupling, which assures that the weaving and shed-forming machines for the further weaving process cannot again be switched together phase-shifted. This single-tooth coupling is constructed relatively strong, namely, a great overlapping of the teeth exists to reduce the flank pressure. Furthermore, only a short time interval exists for effecting re-coupling, namely, the moment when the rotating teeth are aligned. Therefore, a strong spring is built into the pick-finding mechanism, which spring effects a timely and quick recoupling operation.
The strong spring is tensioned by operation of the pick-finding mechanism, which occurs preferably simultaneously with the uncoupling operation, which in turn is carried out by operation of either a switch lever of the pick-finding mechanism or an electromagnet. This tensioning of the spring requires considerable forces which, when tensioning with a switch lever, is a strong load on the operator and, during tensioning with an electromagnet, demands a voluminous electromagnet. Also, it is disadvantageous that the electromagnet works very suddenly, which results in additional loads on the gearing. However, the latter operation does have the advantage that the operation of the electromagnet by means of a push button can be released from any point of the weaver stand.
It is also possible to use the pick-finding mechanism with its motor for the slow-speed, called the creeping speed, operation of a weaving and shed-forming machine. Here too, at the end of the operating process, re-engagement of the coupling is effected by means of an initially tensioned spring.
A goal of the invention is therefore to provide a mechanism which assures a simple mechanical or electromagnetic but not too sudden disengagement of the coupling, with a simultaneous tensioning of the return spring for effecting the re-engagement of the coupling, and without requiring substantial physical effort of the operating personnel.
SUMMARY OF THE INVENTION
This purpose is achieved by providing an apparatus of the above-mentioned type, which is characterized inventively by the provision of a mechanism which effects the tensioning of the return spring through the drive movement of the motor.
A preferred embodiment is a pick-finding mechanism which includes the two-part single-tooth coupling being arranged on a shaft, wherein one part of this coupling is supported axially movably against the force of the return spring and is constructed as a sleeve which is movable on the shaft, and includes a drive gear driven by the motor and supported on the sleeve for limited axial and rotatable movement, preferably against the force of a second stronger spring, the drive gear having on the front side a control cam with at least one axially projecting cam, and including a stop or roller which is arranged on the housing of the apparatus and can be moved into engagement with the cams.
To separate the coupling for starting the pick-finding operation, the operator needs only to move one of the stops into the space between two cams and to permit the motor of the pick finder to run. Uncoupling will then occur automatically and the spring will be initially tensioned for coupling, because the cam will run onto the stop and move the sleeve. The tensioning thus takes place impact-free, by utilizing the motor output. The movement of the stop into the region of the cams can be done manually, or by means of an electromagnet.
BRIEF DESCRIPTION OF THE DRAWINGS
One exemplary embodiment of the invention is illustrated in the drawings, in which:
FIG. 1 illustrates a weaving machine having a shed-forming machine attached thereto;
FIG. 2 is a longitudinal cross-sectional view of an inventive pick-finding mechanism in a "weaving" position;
FIG. 3 is a sectional view taken along the line III--III of FIG. 2;
FIG. 4 is a fragmentary side view of the mechanism of FIG. 2 in a "pick-finding" position;
FIG. 5 is a fragmentary side view of the mechanism of FIG. 2 in a "slow-speed" position; and
FIGS. 6 to 8 diagrammatically illustrate various operating positions of a drive gear, a control cam, and stop rollers which are components of the mechanism of FIG. 2.
DETAILED DESCRIPTION
FIG. 1 illustrates a weaving machine 2, to which is connected a dobby 5. The dobby 5 is driven by a sprocket wheel 1 on the drive shaft of the weaving machine 2 through a chain 3 which is shown in broken lines and a sprocket wheel 4 which is rotatably supported on a shaft 6 of the dobby 5. The sprocket wheel 4 drives the shaft 6 and two bevel gears 7 and 8 of the dobby 5, shown in broken lines, through a not illustrated coupling which is described hereinafter in connection with FIGS. 2-8. A heddle frame 9 can be pulled up against the force of return springs 12 by a rocking lever 10 of the dobby 5 through the heddle-frame actuating cables 11.
The pick-finding mechanism of FIGS. 2-5 is provided on the shaft 6 which is rotatably supported in a conventional manner in shields or sidewalls of the housing 13 of the dobby. It includes the drive sprocket wheel 4 which is rotationally driven by the weaving machine in the manner just described and is fixedly secured on a carrier sleeve 14, one side of which has a claw or tooth 16 which is part of the single-tooth coupling. The sleeve 14 is supported rotatably, but not axially movably, on the shaft 6.
The tooth 16 cooperates with a tooth 17 provided on an axially movable sliding support element or sleeve 18, which is fixed against rotation with respect to the shaft 6 by a key 19. The sliding sleeve 18 in turn rotatably supports a sleeve arrangement which includes a sleeve 15 and a gear 21. The sleeve 15 is rotatably supported the sleeve 18 and in turn rotatably supports the gear 21 which is operatively engaged with the pinion gear 23 of a drive motor 24 for the pick finder. The gear 21 is supported on the sleeve 15 in such a manner that they are capable of relative rotation, limited by the friction effect caused by the action of a tensioned spring 20. The spring 20 is secured at one end against a lateral movement relative to the sleeve 15 by a ring 22, and the other end presses the gear 21 firmly against a shoulder 25 of the sleeve 15. The gear 21 can be moved to the left, together with the sleeve 15 and the sliding sleeve 18, so that the coupling teeth 30 on the side of the sleeve 15 engage the coupling gaps 31 provided in the bevel gear 7, which is fixedly secured on the shaft 6. The axial movability and the friction connection between gear 21 and sleeve 15 produced by the spring 20 provide a safety feature to prevent an overload on the motor, gearing and rollers, for example if the teeth 30 cannot immediately be moved into engagement with the gaps 31.
Relatively axial movement of the sleeve 15 and the sleeve 18 is prevented by an axially facing shoulder 18A (FIG. 2) on the sleeve 18 which engages one end of the sleeve 15 and a ring 41 on the sleeve 18 which engages the opposite end of the sleeve 15. The rings 22 and 41 are preferably split rings which engage circumferential grooves provided in the surfaces of the sleeves 15 and 18, respectively.
A relatively strong helical spring 39 encircles the shaft 6 and has one end disposed against the sleeve 18 and the other end disposed against the bevel gear 7.
The sleeves 15 and 18 and the gear 21 thus form a coupling part movable axially of the shaft 6 between positions operatively engaged with the sleeve or coupling part 14 and the gear or coupling part 7.
The gear 21 has an annular, axially projecting ring 26 on one side thereof, which ring concentrically encircles the shaft 6 and has on its free end a control cam surface 27. The cam surface 27 consists of cams 28 and recesses 29 which are arranged therebetween, the cams 28 and recesses 29 being connected with one another by ramp surfaces 40.
A control arrangement includes plunger rods 32 which are supported for reciprocal axial movement in directions radially of the shaft 6 by bearings 38 of the housing 13. The rods 32 have at their respective upper ends stop rollers 33 and 34 with differing diameters. More specifically, the roller 33 is of greater diameter than the rollers 34, and the rollers 34 are preferably of equal diameter. The lower end of each rod 32 has a head 35 against which a spring 36 is supported. For electromagnetic operation of the rods 32, for example as a plunger-type armature, each is made of iron and is placed in the spool or coil 37 of an electromagnet. Each spring 36 has its upper end disposed against the bottom of the associated coil 37 and urges the associated rod 32 downwardly.
For pick finding, the rod 32 with the large roller 33 is, after the motor of the weaving machine has been switched off, moved against the force of the spring 36 toward the shaft 6, either manually or automatically by exciting the electromagnet coil 37. At the same time, the drive motor 24 of the pick-finding mechanism is switched on, which causes the gear 21 to rotate, and the roller 33 enters a recess 29 of a cam surface 27 as the recess 29 passes it. Further rotation of the gear 21 causes the ramp surface 40 of the cam surface 27 to run up onto the roller 33. Since the rod 32 and the roller 33 thereon are supported stationarily on the housing 13, the gear 21 in FIG. 2 is moved to the left, into the position according to FIG. 4. The gear 21 carries along, due to the spring 20, the retaining ring 22 and the sleeve 15, the sliding sleeve 18. The coupling 30 and 31 thus becomes engaged and the strong spring 39 is compressed. The force of the motor drive is thus used to tension the spring 39 which, after the pick-finding process has ended, effects re-engagement of the single-tooth coupling 16 and 17.
For the purpose of exacting observation of the sequence of machine operation and for stopping the machine in a selected position, the weaving machine and dobby are run slowly, namely at a creeping speed, for example 20 rpm, in a forward or reverse direction. For this, the two rods 32 with the smaller rollers 34 thereon are both moved radially inwardly to an actuating position by electrically actuating the associated coils 37, and at the same time the drive motor 24 of the pick-finding mechanism is switched on. The drive motor of the weaving machine is switched off, and the brake on the weaving machine is released. As one of the recesses 29 of the cam surface 27 passes the rollers 34, the rollers 34 enter and engage the recess 29 and the ramp surfaces 40 of the cams run onto the rollers 34. The sliding sleeve 18 is thereby moved to a position about halfway along its path of travel to the left, as shown in FIG. 5. In this position, the couplings 30 and 31 and 16 and 17 are both partially engaged. As long as the rods 32 having the rollers 34 thereon remain in the moved-in position, the weaving machine and dobby will be driven by the motor 24. When either one of the rollers 34 reaches the area of a recess 29 due to rotation of the gear 21, the other roller 34 will be resting on a cam 28 and maintain the lateral shift of the sleeve 18.
FIGS. 6-8 illustrate diagrammatically the various positions that the rollers 33 and 34 can assume with respect to the control cam surface 27.
FIG. 6 corresponds to the position according to FIGS. 2 and 3, namely where none of the rods 32 are moved in and all of the rollers 33 and 34 are spaced radially outwardly from the cams 28 and recesses 29 on the ring 26.
FIG. 7 corresponds to the "pick-finding" position according to FIG. 4, namely where the rod 32 with the large roller 33 thereon has moved in and the roller 33 engages the cam 28. The gear 21 has thus been moved axially by the roller 33. The rollers 34 are, at this time, without any function.
FIG. 8 corresponds to the position according to FIG. 5 for the slow speed of the coupled weaving machine and dobby. The two rods 32 with the smaller rollers 34 are moved in and the rollers 34 alternately or simultaneously engage the cams 28 as the gear 21 rotates. The gear 21 is displaced axially by the rollers 34 approximately half the distance that it is displaced in FIG. 7. The roller 33 is, at this time, without any function.
When the electricity supplied to a selected one of the electromagnets is turned off, the associated rod 32 is moved downwardly under the urging of the associated spring 36, moving the associated roller 33 or 34 to a retracted position in which it is out of engagement with the cam surface 27.
After the rods 32 are no longer held in the pushed-in position, the apparatus returns to the basic position, namely the weaving position of FIG. 2 from the positions of FIGS. 7 and 8 under the urging of the tensioned spring 39.
Thus, the force for tensioning the strong return spring 39 need not be produced manually for starting the pick finding or the slow-speed operation in the described apparatus, nor is a voluminous magnet needed for this. Rather, the moving in of the rods 32 having the rollers 33 and 34 thereon requires an extremely small force expenditure.
From the description in connection with FIGS. 6-8 of the sequence of movement of the gear 21 with the cams 28 thereon and thus the movement of the sleeve 18, it becomes clear that, in place of the rollers 33 and 34 of various diameters, it would also be possible to use rollers having uniform diameters. The plunger rods 32 must then be arranged so that their central axes are offset relative to each other in a direction axially along the shaft 6. More specifically, the axes of the two rods 32 which control the slow-speed operation must be farther from the control cam surface 27 in a direction axially of the shaft 6 than the rods 32 which control the pick-finding operation.
Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention. | In a pick finder, a gear which is driven by a motor sits on a sleeve, which has thereon a tooth of a single-tooth coupling. For tensioning the return spring which effects engagement of the coupling, the gear has on the front side an annular control cam surface with recesses and cams, and rigid rollers can be brought into contact therewith through axial movement thereof with respect to the shaft. Based on the size and the placement of the respective rollers, engagement thereof with the cam surface on the gear rotated by the drive motor of the pick finder will move the sleeve into a position for pick finding or for slow-speed run of the weaving machine with the shed-forming machine. At the same time, the return spring is tensioned by the force of the motor. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is the US National Stage of International Application No. PCT/EP2004/006624, filed Jun. 18, 2004 and claims the benefit thereof. The International Application claims the benefits of European Patent application No. 03015496.7 EP filed Jul. 9, 2003, all of the applications are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
The invention relates to a turbine blade which has a blade height, a rotor-side end and a stator-side end, a leading edge and trailing edge and a suction side and delivery side and which is designed for use in relation to a general direction of flow, and also to a turbomachine which is equipped with such a turbine blade.
BACKGROUND OF THE INVENTION
In steam turbine construction, for example, curved guide blades are used as an embodiment of turbine blades especially when high three-dimensional flows occur which exhibit pronounced radial differences in the static pressure profile between the rotor side and the stator side, these differences arising due to deflection in the guide blades. In steam turbines, especially in low-pressure turbines with a large outflow cross section, the blade length to hub ratio is relatively high. The flow of a flow medium in the last stage of a low-pressure turbine having a large inflow cross section leads, in the case of a high blade length to hub ratio, to a radial reaction distribution which has an adverse effect on the efficiency of the steam turbine. The reaction distribution is in this case different in the radial direction and is low at the hub and high at the casing, this being felt to be a disadvantage.
In a thermal turbomachine, the percentage fraction of the isentropic enthalpy gradient in moving blades in relation to the entire isentropic enthalpy gradient over a stage consisting of a guide blade ring and a moving blade ring is designated as the isentropic reaction degree r. Such a stage in which the reaction degree is r=0 and the highest enthalpy gradient occurs is designated as a straightforward constant-pressure stage.
In a conventional excess-pressure stage, the reaction degree is r=0.5, so that the enthalpy gradient in the guide blades is exactly the same as in the moving blades. A reaction degree of r=0.75 is designated as a strong reaction. In steam turbine construction practice, the conventional excess-pressure stage and the constant-pressure stage are predominantly employed. As a rule, however, the latter has a reaction degree somewhat different from zero.
A low or even negative reaction of the hub leads to severe impairments and to efficiency losses of the turbine during operation. A high reaction of the casing gives rise to a high attack velocity of the moving blades in the tip region. The high attack velocity has an adverse effect on efficiency, since the behavior of flow losses is squarely proportional to velocity. A reduction in the reaction would remedy this. Moreover, a lower reaction of the casing would lead to a reduction in the gap losses, and the efficiency would thereby be additionally improved.
A high reaction in the hub region reduces the gap losses in the guide blade ring and thus leads to improved efficiency.
Curved guide blades are in this case used, in particular, in order to optimize the radial reaction distribution.
Turbines with guide blades curved only in the circumferential direction are known, for example, from DE 37 43 738. This shows and describes blades, the curvature of which is directed over the blade height toward the delivery side of the guide blade in each case adjacent to the circumferential direction. This publication also discloses blades, the curvature of which is directed over the blade height toward the suction side of the guide blade in each case adjacent to the circumferential direction.
Consequently, both radial and circumferentially running boundary layer pressure gradients are to be effectively reduced, and consequently the aerodynamic blade losses are to decrease in size.
Turbines with guide blades curved in the direction of flow and in the circumferential direction are known, for example, from DE 42 28 879.
Curved guide blades are also known from U.S. Pat. No. 6,099,248.
SUMMARY OF THE INVENTION
The object of the present invention is to specify a turbine blade and turbomachine in which the efficiency is improved.
In the turbine blade initially described, this is achieved, according to the invention, by means of the characterizing features as described in the claims.
The advantage of the invention is to be seen, inter alia, in that the radial reaction distribution is improved as a result of the improved inflow.
Further advantageous refinements are described in the subclaims.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention are illustrated by means of the figures. In the figures, functionally similar components are designated by the same reference symbols.
In the figures:
FIG. 1 shows a side view of a final stage, equipped with a turbine blade, of a turbomachine;
FIG. 2 shows a view of a guide blade in the direction of flow of a flow medium;
FIG. 3 shows a blade with an illustration of a reaction distribution according to the prior art and of a turbine blade according to the invention, shown in FIG. 1 ;
FIG. 4 shows a diagrammatic and perspective illustration of the turbine blade of FIG. 1 at a rotor-side end;
FIG. 5 shows a diagrammatic and perspective illustration of the turbine blade of FIG. 1 at a stator-side end;
FIG. 6 shows a perspective view of a turbine blade.
DETAILED DESCRIPTION OF THE INVENTION
In the steam turbine final stage shown diagrammatically in a side view in FIG. 1 , the walls delimiting a throughflow duct 1 are, on the one hand, a rotor-side duct wall 3 and, on the other hand, a stator-side duct wall 5 . The stator-side duct wall 5 belongs to an inner casing 6 . A final stage consists of a row of guide blades and a row of moving blades, of which in each case only one guide blade 10 and one moving blade 11 is shown in FIG. 1 for the sake of clarity. The guide blades are fastened to the inner casing 6 in a way not illustrated.
The moving blades are fastened in the rotor 2 in a way not illustrated.
The guide blade 10 has a stator-side end 7 , a middle region 8 and a rotor-side end 9 . A flow medium can flow through the duct 1 in the direction of flow 4 . The direction of flow 4 is essentially parallel to an axis of rotation 12 of the rotor 2 . The guide blade 10 has a leading edge 13 and a trailing edge 14 which are formed over the entire blade height.
The moving blade 11 likewise has a leading edge 15 and a trailing edge 16 .
As illustrated in FIG. 6 , the disposition of the turbine blade 10 is described by means of a turbine blade form curve 39 . The turbine blade 10 is divided into cylinder surfaces 40 . For the sake of clarity, only six cylinder surfaces 40 are illustrated in FIG. 6 . The turbine blade form curve 39 describes the disposition more accurately, the more cylinder surfaces 40 are formed. For each cylinder surface 40 , its mass center of gravity 41 is determined. The turbine blade form curve 39 is formed by connecting the mass centers of gravity 41 from a turbine blade root 42 to the turbine blade tip 43 .
As is evident from FIG. 1 , the turbine blade form curve 39 terminates in each case at the rotor-side end 9 and at the stator-side end 7 of the turbine blade 10 . The statements refer below to a turbine blade designed as a guide blade 10 .
The turbine blade form curve 39 is considered at its rotor-side end 9 , and the three-dimensional form of the turbine blade form curve 39 is depicted by a tangent which is to be understood as the mathematical derivation of the turbine blade form curve 39 in a curve direction. The tangent or mathematical derivation is designated at the rotor-side end 9 of the turbine blade form curve 39 as an auxiliary tangent 17 . In other words: the three-dimensional form or the disposition of the turbine blade 10 at the rotor-side end 9 is illustrated by the auxiliary tangent 17 .
The guide blade 10 is shaped at its rotor-side end 9 in such a way that it has a negative sweep in the direction of flow 4 . Of course, the auxiliary tangent 17 likewise has a negative sweep with respect to the direction of flow 4 .
The disposition of the stator-side end 7 of the guide blade 10 is illustrated by a second auxiliary tangent 18 . In this case, the turbine blade form curve 39 is considered at its stator-side end 7 , and the three-dimensional form of the turbine blade form curve 39 is depicted by a tangent which is to be understood as a mathematical derivation of the turbine blade form curve 39 in a curve direction.
The guide blade 10 is shaped at its stator-side end 7 in such a way that it has a negative sweep in the direction of flow 4 . Of course, the auxiliary tangent 18 likewise has a negative sweep with respect to the direction of flow 4 .
The disposition of the guide blade 10 is described in the center, in the middle region 8 , essentially by an auxiliary tangent 65 . In this case, the turbine blade form curve 39 is considered in its middle region 8 , and the three-dimensional form of the turbine blade form curve 39 is depicted by the auxiliary tangent 65 which is to be understood as a mathematical derivation of the turbine blade form curve 39 in a curve direction. This starts from a point of the guide blade form curve 39 which lies in the middle region 8 and at this point forms a tangent or derivation produced as an auxiliary tangent 65 .
The guide blade 10 is shaped in its middle region 8 in such a way that it has a positive sweep in the direction of flow 4 . Of course, the auxiliary tangent 65 likewise has a positive sweep with respect to the direction of flow 4 .
In an alternative embodiment, the middle region 8 may also have a negative sweep or even be perpendicular to the direction of flow 4 .
Negative and positive sweeps are defined here as follows:
negative sweep: the direction of flow 4 must be rotated through an acute angle in a mathematically negative direction (clockwise) with respect to the auxiliary tangent 17 or to the auxiliary tangent 18 , in order to achieve a coincidence of the direction of flow 4 with the auxiliary tangent 17 or 18 .
Positive sweep: the direction of flow 4 must be rotated through an acute angle in a mathematically positive direction (counterclockwise) with respect to the auxiliary tangent 65 , in order to achieve a coincidence of the direction of flow 4 with the auxiliary tangent 65 .
The distance between the trailing edge 14 of the guide blade 10 and the leading edge 15 of the adjacent moving blade 11 is constant at the rotor-side end 9 and in the middle region 8 .
In an alternative embodiment, the distance between the trailing edge 14 of the guide blade 10 and the trailing edge 15 of the adjacent moving blade 11 may be different.
The rotor-side end 9 and the stator-side end 7 lie essentially one above the other in the direction of flow 4 .
A view in the direction of flow 4 is illustrated in FIG. 2 . The guide blade 10 lies between a delivery side 21 and a suction side 22 . The middle line, shown in FIG. 2 , between the delivery side 21 and the suction side 22 constitutes the leading edge 13 . The direction of flow 4 runs essentially perpendicularly with respect to the drawing plane. The flow medium in this case flows along the direction of flow 4 and impinges first onto the leading edge 13 of the guide blade 10 .
The rotor-side end 9 of the guide blade 10 is inclined in the direction of the delivery side 21 . The stator-side end 7 is likewise inclined toward the delivery side 21 .
In the middle region 8 of the guide blade 10 , the guide blade 10 is inclined toward the suction side 22 .
In an alternative embodiment, the middle region 8 may also be inclined toward the delivery side 21 . In a further alternative embodiment, the middle region may be inclined neither toward the delivery side 21 nor toward the suction side 22 .
However, in an alternative exemplary embodiment of the turbine blade, the middle region may also be oriented in a radial direction 34 .
The leading edge 13 is positioned essentially upstream of the trailing edge 14 at the rotor-side end 9 of the guide blade 10 .
The leading edge 13 is positioned essentially upstream of the trailing edge 14 in the direction of flow 4 at the stator-side end 7 of the guide blade 10 .
In the middle region, the trailing edge 14 is displaced toward the delivery side 21 with respect to the leading edge 13 .
The stator-side end 7 of the guide blade 10 is displaced in the radial direction 34 toward the delivery side 21 with respect to the rotor-side end 9 .
In FIG. 4 , a diagrammatic and perspective illustration of the turbine blade 10 , 11 at the rotor-side end 9 can be seen and serves for a more detailed explanation of the position of the auxiliary tangent 17 and of angles α and γ which are related to this.
The three-dimensional form of the turbine blade 10 has not been illustrated for the sake of clarity. The turbine blade 10 is illustrated at the rotor-side end 9 by the auxiliary tangent 17 .
The auxiliary tangent 17 would, if prolonged in the direction of the rotor 2 , touch the rotor 2 at a point 44 . A first auxiliary axis 20 intersects the axis of rotation 12 perpendicularly and runs through the point 44 .
A second auxiliary axis 23 intersects the first auxiliary axis 20 at the point 44 and runs essentially parallel to the direction of flow 4 which, in this exemplary embodiment, is parallel to the axis of rotation 12 .
A third auxiliary axis 24 intersects the first auxiliary axis 20 at the point 44 and runs perpendicularly with respect to the first auxiliary axis 20 and perpendicularly with respect to the second auxiliary axis 23 .
The first auxiliary axis 20 and the second auxiliary axis 23 form a first projection plane 45 . The first auxiliary axis 20 and the third auxiliary axis 24 form a second projection plane 46 .
The auxiliary tangent 17 is projected onto the first projection plane 45 , in that each point of the auxiliary tangent 17 is projected onto the first projection plane 45 in the direction of the third auxiliary axis 24 .
This is explained, by way of example, with reference to a point 47 of the auxiliary tangent 17 . The point 47 is projected along a first projection straight line 48 , in a direction running parallel to the third auxiliary axis 24 , onto a first projection point 49 lying in the first projection plane 45 . A first projection straight line 17 ′ is thus projected onto the first projection plane 45 .
The first projection straight line 17 ′ is inclined at an angle α with respect to the second auxiliary axis 23 .
The angle α may in this case assume values of between 0° and 90°, in particular the value of the angle α lies between 50° and 80°.
The auxiliary tangent 17 is also projected onto the second projection plane 46 , in that each point of the auxiliary tangent 17 is moved in the direction of the second auxiliary axis 23 onto the second projection plane 46 until this is touched.
This is explained by way of example, with reference to the point 47 of the auxiliary tangent 17 . The point 47 is projected along a second projection straight line 51 , in a direction running parallel to the second auxiliary axis 23 , onto a second projection point 52 lying in the second projection plane 46 . A second projection straight line 17 ″ is thus formed on the second projection plane 46 .
The second projection straight line 17 ″ is inclined at an angle γ with respect to the first auxiliary axis 20 .
The angle γ may assume values which lie between 0° and 90°, in particular the angle γ lies at 70°.
The rotor-side end face of the turbine blade 10 is indicated by a dashed line run 54 .
In FIG. 5 , a diagrammatic and perspective illustration of the turbine blade 10 of the stator-side end 7 can be seen and serves for a more detailed explanation of the positions of the auxiliary tangent 18 and of angles β, δ and ξ which are related to this.
The three-dimensional form of the turbine blade 10 has not been illustrated for the sake of clarity. The turbine blade 10 is illustrated at the stator-side end 7 by the auxiliary tangent 18 .
The auxiliary tangent 18 would, in its prolongation in the direction of the inner casing 6 , touch the inner casing 6 at a point 55 .
A fourth auxiliary axis 26 intersects the axis of rotation 12 perpendicularly and runs through the point 55 . A fifth auxiliary axis 27 intersects the fourth auxiliary axis 26 at the point 55 and runs parallel to a surface of the inner casing at the point 55 . A sixth auxiliary axis 28 intersects the fourth auxiliary axis 26 perpendicularly at the point 55 and runs perpendicularly with respect to the fifth auxiliary axis 27 .
The fourth auxiliary axis 26 and the fifth auxiliary axis 27 form a third projection plane 56 . The fourth auxiliary axis 26 and the sixth auxiliary axis 28 form a fourth projection plane 57 .
The auxiliary tangent 18 is projected onto the third projection plane 56 , in that each point of the auxiliary tangent 18 is moved in the direction of the sixth auxiliary axis 28 onto the third projection plane 56 until it touches the latter.
This is explained, by way of example, by means of a point 58 of the auxiliary tangent 18 . The point 58 is projected along a third projection straight line 59 , in a direction running parallel to the sixth auxiliary axis 28 , onto a third projection point 60 lying in the third projection plane 56 . A third projection tangent 18 ′ is thus projected onto the third projection plane 56 .
The projection tangent 18 ′ is inclined at an angle ξ with respect to the fifth auxiliary axis 27 . The angle ξ lies between 0° and 180°.
The projection tangent 18 ′ is also inclined at an angle β with respect to the axis of rotation 12 . The angle β may assume essentially values of between 0° and 90°.
The auxiliary tangent 18 is also projected onto the fourth projection plane 57 , in that each point of the auxiliary tangent 18 is moved in the direction of the fifth auxiliary axis 27 onto the fourth projection plane 57 until it touches the latter.
This is explained, by way of example, by means of the point 58 of the auxiliary tangent 18 . The point 58 is projected along a fourth projection straight line 62 , in a direction running parallel to the fifth auxiliary axis 27 , onto a fourth projection point 63 lying in the fourth projection plane 57 . A fourth projection tangent 18 ″ is thus projected onto the fourth projection plane 57 .
The projection tangent 18 ″ is inclined at an angle δ with respect to the sixth auxiliary axis 28 . The angle δ lies between 0° and 90°, preferably the angle δ is 75°.
FIG. 3 illustrates, as a graph, a reaction distribution as a function of a blade height. The X-axis 35 in this case represents the reaction distribution in arbitrary units. The Y-axis 36 in this case represents the distance from a hub. The dashed line 37 shows the profile of the reaction distribution according to the previous prior art. The unbroken line 38 shows the profile of the reaction distribution when the guide blades are designed according to the invention illustrated here.
As mentioned initially, it is a disadvantage if the reaction distribution in the radial direction 34 is different. The dashed line 37 , which illustrates the reaction distribution according to the previous prior art, shows the abovementioned behavior which is felt to be a disadvantage. According to this, the reaction distribution from the hub to the casing is different. The unbroken line 38 shows an improved reaction distribution, as compared with the dashed line 37 . | A turbine blade is provided, comprising a stator-side end located toward a stationary stator cylinder of the turbine, a rotor-side end located toward an axial rotor of the turbine, a leading edge located between the stator-side end and the rotor-side end, a trailing edge located between the stator-side end and the rotor-side end and located down-stream of the leading edge with respect to a fluid flow direction, wherein the rotor-side and stator-side ends have a negative sweep angle as measured between the instantaneous tangent of the blade surface and the fluid flow direction. Also, a turbine blade is provided, comprising a stator-side end located toward a stationary stator cylinder of the turbine, a rotor-side end located toward an axial rotor of the turbine, a delivery side located between the stator-side end and the rotor-side end, a suction side located between the stator-side end and the rotor-side end and located down-stream of the leading edge with respect to a fluid flow direction, wherein the rotor-side end is inclined toward the delivery side and the stator-side end is inclined with respect to a fluid flow direction. | 5 |
This is a continuation application of Ser. No. 06/765,211 filed 08/13/85, now abandoned.
FIELD OF THE INVENTION
This invention relates to a microwave oven with means for launching microwave power into a cavity of the oven from a launch area in the base of the cavity.
In a microwave oven microwave power is transferred from a magnetron to the oven cavity in dependence upon the effectiveness of the coupling between the load of the oven cavity and the magnetron. Hitherto, microwave ovens have been designed to achieve optimum coupling for a wide range of loads corresponding to differing sizes and densities of food items placed in the cavity. This optimization of coupling means that for a given input power to the magnetron the power into the cavity is optimized over the range of loads placed in the oven cavity. The invention adopts an entirely different approach by aiming to provide a microwave oven having a cavity which, when devoid of food, is a poor power match with the magnetron, with the result that the amount of power transferred from the magnetron to the food item being cooked is dependent almost entirely on the load of the food item.
SUMMARY OF THE INVENTION
According to the invention a microwave oven has a magnetron for producing microwave power to a cavity of the oven, means for launching the microwave power into the cavity from a launch area in the base of the cavity, and a metal tray supported in the cavity above the launch area with the peripheral edge of the tray spaced from the cavity walls so that the oven when devoid of food provides an inefficient power match with the magnetron, whereby the dielectric load of food items placed in the oven determines the power coupled to the loaded oven from the magnetron. Accordingly, in the invented microwave oven the amount of microwave power coupled into the loaded oven is substantially proportional to the dielectric load. The result of this is that the microwave oven need not have selectable microwave power settings which the user must first preset, because the load of the food item itself determines the amount of power delivered by the magnetron to the loaded cavity.
In one embodiment, the tray is stove enamelled and of rectangular or square shape. The tray may be supported in the oven by a wire rack or shelf which rests on shelf supports provided on the oven walls and which wire rack or shelf supports the tray so that the peripheral edges thereof are spaced from the oven walls. Such walls normally include the oven side walls, the oven back panel and the oven door when closed.
Said tray may be the lower of two vertically spaced trays, either or both of which may support food to be cooked.
The tray (or the lower of the two trays if two are fitted) must be spaced above the launch area by a dimension which is such that the tray presents to the magnetron a load which is a poor match for the magnetron in terms of effectiveness of power transfer from the magnetron to the oven cavity. In a particular example it has been found that the tray (or the lower tray) should be spaced between ninety and ninety-five millimeters above the base of the oven cavity from which the microwave power is launched.
The oven preferably has thermal heating means in addition to the magnetron, the thermal heating means providing a forced flow of hot air through the cavity, as a result of air being blown over an electrical resistance heating element by means of a fan. The airflow pattern is preferably such that the hot air enters the oven cavity from one side thereof through a vertically elongated inlet, passes across the oven cavity to the other side thereof where the air is drawn out of the cavity by a fan, this airflow pattern being disclosed in our U.K. patent specification No. 2127658.
In another embodiment, the tray is circular and forms part of a rotatable turntable. The tray may be the lower of two such vertically spaced and interconnected trays which effectively form a two-tier turntable. Food may be placed on the lower tray, leaving the upper tray vacant, or vice versa, or food may be placed on both trays, but in any event the loading provided by the food in the cavity determines the amount of energy coupled to the cavity by the magnetron.
The turntable is preferably driven by a rotatable drive member extending upwardly through the base of the cavity, and this drive member may be arranged concentrically with a further drive member which rotates a mode stirrer in the base.
The positioning and size of the two trays in the cavity are important factors in ensuring that the trays present a load which is a poor match for the magnetron in terms of effectiveness of power transfer from the magnetron to the oven cavity. In a particular example it has been found that good results are obtained if the lower tray is between twenty and twenty-five millimeters (preferably about twenty-two millimeters) above the base, the upper tray is between one hundred and seventy and one hundred and ninety millimeters (preferably one hundred and eighty millimeters above the lower tray, and both trays are between three hundred and eighty and four hundred millimeters in diameter. Each tray will normally be made of sheet metal, which may be stove enamelled, and the two trays may be detachably connected together by legs or columns which support the upper tray at the desired spacing above the lower tray.
The air flow pattern is preferably such that hot air is forced into the cavity through two inlets in a rear wall of the cavity, and leaves the cavity through two outlets in the rear wall.
The oven may have a first inlet for the admission of hot air into the cavity above the upper tray and a first outlet for the exit of hot air from the cavity above the upper tray, a second inlet for the admission of hot air into the cavity between the upper and lower trays and a second outlet for the exit of hot air between the upper and lowet trays. There is thus a first hot air circulation system for the space above the upper tray, and a second hot air circulation system for the space between the upper and lower trays.
The trays may be shelves slidably supported in the cavity, but are preferably constituted by the tiers of a two-tier turntable which is rotatably driven about a vertical axis within the cavity.
The first and second inlets and the first and second outlets may be in a rear wall of the cavity with the first inlet disposed above the second outlet and the second inlet disposed above the first outlet so that the directions of forced air flow above and below the upper tray are mutually opposite. The rear wall immediately behind the upper tray and the lower tray is preferably devoid of any hot air inlet or outlet.
Each outlet preferably has a corresponding fan which draws air out of the cavity and through the outlet, before being forced over an electrical resistance heating element which heats the air prior to its re-entry into the cavity through the corresponding inlet. There are preferably two electrical resistance heating elements, one for each hot air circulation system, enabling independent control to be exercised over the forced hot air regime in the two spaces on respective sides of the upper tray.
In a further embodiment, the tray constitutes the sole food-supporting member and is rotatably mounted in the base of the cavity. The turntable is preferably driven by a rotatable drive member extending upwardly through the base of the cavity, and this drive member may be arranged concentrically with a further drive member which rotates a mode stirrer in the base.
The positioning and size of the tray in the cavity are important factors in ensuring that the tray presents a load which is a poor match for the magnetron in terms of effectiveness of power transfer from the magnetron to the oven cavity. In a particular example it has been found that good results are obtained if the tray is between twenty and twenty-five millimeters (preferably about twenty-two millimeters) above the base, and is between three hundred and four hundred millimeters in diameter. The tray will normally be made of sheet metal, which may be stove enamelled.
The oven preferably has thermal heating means in addition to the magnetron, the thermal heating means providing a forced flow of hot air through the cavity, as a result of air being blown over an electrical resistance heating element by means of a fan. The air flow pattern is preferably such that hot air is forced into the cavity through two inlets in a rear wall of the cavity, and leaves the cavity through two outlets in the rear wall.
Three embodiments of microwave oven according to the invention will now be described by way of example with reference to the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the first embodiment of oven with a door of the oven omitted for clarity,
FIG. 2 is a front elevation of the oven of FIG. 1, showing shelves and trays of the oven removed,
FIG. 3 is a perspective view of an oven shelf of the oven of FIG. 1,
FIG. 4 is a perspective view of an oven tray of the oven of FIG. 1,
FIG. 5 is a sectional view showing the shape of the tray of FIG. 4,
FIGS. 6 and 7 are views similar to FIG. 2 and show two modified constructions,
FIG. 8 is a perspective view of the oven cavity of the second embodiment of oven, with a door and surrounding structure removed,
FIG. 9 is an elevation of a rear wall of the oven cavity of FIG. 8 showing inlet and outlet apertures for a forced flow of hot air,
FIG. 10 is a diagrammatic elevation of a rear wall of the oven cavity, showing inlets and outlets for forced flow of hot air in a hot air system alternative to that of FIG. 9,
FIG. 11 is a perspective view of the oven cavity of the third embodiment of oven with a door and surrounding structure removed, and
FIG. 12 is an elevation of a rear wall of the oven cavity of FIG. 11, showing inlet and outlet apertures for a forced flow of hot air.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the oven is generally rectangular in shape, having two side walls 2, 4, a back panel 6 a top panel 8 and a base panel 10. Within the base panel 10 is a circular aperture 12 forming a launch area through which microwave power is launched into the oven cavity from a magnetron indicated diagrammatically at 11. A rotationally driven member 14 (FIG. 2) located in the aperture 12 acts to distribute the microwave energy throughout the cavity.
A pair of upper shelf supports 16 and a pair of lower shelf supports 18 are attached to the side walls 2 and 4. The upper supports 16 support an upper shelf 20, and the lower supports 18 support a lower shelf 22. The upper shelf 20 carries an upper metal tray 24 and the lower shelf 22 carries a lower metal tray 26. FIG. 3 shows the shelf 22, it being understood that the shelf 20 is identical, and FIG. 4 shows the tray 26, it being understood that the tray 24 is identical.
The shelf 22 is made of metal rod and is like a conventional oven shelf except that the central portion is an enlarged aperture 28 to receive the tray 26. The tray 26 is of metal and its entire surface is stove enamelled to prevent metal to metal contact between the tray and the shelf. The tray 26 is rectangular in shape and has around all four edges an out-turned flange or lip 30 which rests on the metal shelf 22 to support the tray in the position shown in FIG. 1.
Referring to FIG. 2, the back panel 6 mounts a panel 32 formed with plurality of perforations comprising smaller inlet holes for a supply of hot air forced into the oven cavity by means of a fan located in a compartment behind the back panel 6. After passing through the cavity, the hot air is drawn out of the cavity through a circular outlet aperture 34. The fan then causes the air to pass over an electrical resistance heating element whence it is recirculated through the oven cavity. Air flow through the cavity is indicated by lines 25 in FIG. 2.
Both trays 24 and 26 are supported in the oven cavity so that their out-turned lips 30 are spaced from the side walls 2 and 4, the back panel 6 and the oven door when closed. This ensures that there is space around all four sides of each tray 24 or 26 to enable microwave energy to reach the regions above the trays. The positioning of the lower tray 26 is important as it must be spaced from the launch area by a distance so that the tray 26 presents to the magnetron a load which is a poor match with respect to the magnetron. As a result, the amount of power delivered by the magnetron to the empty oven is small, and this low degree of power coupling can be seen on a Rieke diagram.
If a food item is now placed on the lower tray 26 the effectiveness of coupling is slightly increased and the load (ie the food item) absorbs microwave power in accordance with its dielectric properties. If the same food item is placed on the upper tray 24 instead of the lower tray 26 the same result is achieved. If two food items are placed respectively on the two trays 24 and 26 the degree of power coupling between the loads and the magnetron is increased, and the power input to the cavity is increased but the power absorbed by each load remains the same, or substantially the same. This important result means that a food item will take the same time to be cooked regardless of which tray 24 or 26 the load is placed upon and regardless of whether the other tray is loaded or not. The same result is achieved if food is supported on the shelf or shelves 20, 22, the trays 24, 26 having previously been removed.
A particular oven used for tests has a cavity height of three hundred and ninety-six millimeters, a cavity depth of four hundred and twenty millimeters, a cavity width of four hundred and fifty millimeters, a lower shelf 22 spaced ninety millimeters above the base panel 10 and an upper shelf 24 two hundred and thirty millimeters above the base panel 10. Each tray 24 or 26 is three hundred and ten millimeters square and is twenty millimeters deep. With such a configuration it has been found that the dielectric load of food items placed in the cavity determines the extent of power coupling from the magnetron into the cavity and in consequence the amount of power absorbed by any food item (and therefore the time taken to cook) is dependent almost entirely on the dielectric properties of the food item. This means that the food item determines the amount of power which it absorbs so that it is not necessary for the operator to preselect any particular microwave power setting.
FIG. 6 shows the back panel 6 of the cavity of an oven having a modified air flow pattern. The panel 6 has two perforated pnels 32 mounted thereon, forming hot air inlets, and two circular apertures 34 which are hot air outlets. The flow of hot air through the cavity is generally symmetrical with respect to the central vertical plane of the oven, the air flow pattern being indicated by lines 25 in FIG. 6.
A further modification of the air flow pattern is shown in FIG. 7. Two perforated panels 32 forming hot air inlets are mounted as before on panel 6, but in this case the circular apertures 34 which are the hot air outlets are different locations. One of the outlets is adjacent the top of the back panel 6, and the other adjacent the bottom of the back panel 6, the resulting air flow pattern being shown by lines 25. It will be noted that in FIG. 7 the air flow passes across the central vertical plane of the oven.
Instead of having slidable shelves supporting trays which are stationary during cooking, the oven may have one or more food-supporting shelves rotatable about a central vertical axis in the cavity. In this case, the rotatable tray, and the lower rotatable tray if there are a plurality of trays, performs the same function as tray 26 in presenting to the magnetron a poor load match. Referring to FIG. 8, the second embodiment of oven is generally rectangular in shape and the cavity is defined by two side walls 42, 44 and a back wall 46, a top panel 48 and a base panel 50. Microwave power is launched into the cavity through a rectangular aperture 52 in the base panel 50. A mode stirrer (not shown) is mounted in the aperture 52 and is rotabably driven about a vertical axis.
The cavity accommodates a removable two-tier turntable 54 having an upper tray 56 and a lower tray 58. Each tray 56 or 58 has a circular base three hundred and ninety millimeters in diameter, surrounded by an upstanding wall or rim twenty-five millimeters high. Each tray is formed of sheet metal which may be stove enamelled. The cavity may have a height of four hundred millimeters, a width of four hundred and fifty millimeters and a depth of four hundred and eighteen millimeters. The two trays 56, 58 are detachably interconnected by three columns 60, which are made of a synthetic plastics material such as PTFE and which provide a spacing of one hundred and eighty millimeters between the trays 56, 58. The lower tray is spaced twenty-two millimeters above the base panel 50, and the underside of the lower tray is engaged by rollers 62 which are mounted on the base panel 50.
Drive means for rotating the turntable extend upwardly through the aperture 52 and is shown diagrammatically at 64. Such drive means is coaxially arranged with the drive to the mode stirrer, for example by the turntable being rotatably driven by a central vertical shaft surrounded by a drive sleeve driving the mode stirrer. The drive shaft and drive sleeve are driven at their appropriate speeds, e.g. by belt drives from a motor. It will be appreciated that all this structure will be positioned below the cavity but within the oven outer casing which is not shown in the drawings.
A forced air flow of hot air is passed through the cavity simultaneously with the application of microwave power, so that food items placed on the upper tray 56, the lower tray 58 (or both trays) are subjected both to hot air and microwave power. FIG. 9 shows the hot air inlets and outlets in the back wall 46, as the latter is viewed from the front of the oven. The back wall 46 has two vertically elongated panels, each having a plurality of inlets 66 through which hot air is forced by a fan to enter the cavity. Having passed over the food items, the air leaves the cavity through the circular air outlets 68. The air is then forced over an electric resistance heating element (disposed in a compartment behind the rear wall 46) before being recirculated through the inlets 66 and the cavity. The lines with arrows in FIG. 9 depict the air flow diagrammatically: it will be appreciated that the hot air is forced forwardly into the cavity from the inlets 66 before being drawn back to the outlets 68. It will also be appreciated that the cavity has a moisture vent, for example in the back wall 46.
The trays 56 and 58 and the columns 60 are detachable from one another but are capable of being interengaged so as to form a unit which rotates as a whole in the cavity during use. The turntable therefore rotates about a central vertical axis, the underside of the lower tray 58 engaging the rollers 62.
FIG. 10 shows an alternative hot air system to that of FIG. 9. The back wall 46 has a first panel having a plurality of hot air inlets 76 and a first hot air outlet 78, both disposed above the upper tray 56. Also, the back wall has a second panel having a plurality of hot air inlets 80 and a second hot air outlet 82, both disposed below the upper tray 56 but above the lower tray 58. Each plurality of hot air outlets 78 and 82 has its own fan which draws hot air from the cavity, passes the air over a corresponding one of two electrical resistance heating elements behind the wall 46 and then back into the cavity by the corresponding inlet. In consequence, there is a first hot air system serving the cavity above the upper tray 56, and a second hot air system serving the cavity between the trays 56 and 58. Each hot air system may be controlled independently of the other. The hot air inlets 76 are disposed above the outlet 82, and the hot air inlets 80 are disposed below the outlet 78, so that the hot air flow is generally from right to left above the tray 56, and from left to right in the space between the trays 56 and 58.
Referring to FIG. 11, the third embodiment of oven is again generally rectangular in shape and the cavity is defined by two side walls 92, 94, a back wall 96, a top panel 98 and a base panel 100. Microwave power is launched into the cavity through a rectangular aperture 102 in the base panel 100. A mode stirrer (not shown) is mounted in the aperture 102 and is rotatably driven about a vertical axis.
The cavity accommodates a removable turntable in the form of a metal tray 104. The tray 104 has a circular base three hundred and ninety millimeters in diameter, surrounded by an upstanding wall or rim twenty-five millimeters high. The tray is formed of sheet metal which may be stove enamelled. The cavity may have a height of four hundred millimeters, a width of four hundred and fifty millimeters and a depth of four hundred and eighteen millimeters. The tray 104 is spaced twenty-two millimeters above the base panel 100, and the underside of the tray 104 is engaged by rollers 106 which are mounted on the base panel 100.
Drive means for rotating the turntable extend upwardly through the aperture 102 and is shown diagrammatically at 108. Such drive means is coaxially arranged with the drive to the mode stirrer, for example by the turntable being rotatably driven by a central vetical shaft surrounded by a drive sleeve driving the mode stirrer. The drive shaft and drive sleeve are driven at their appropriate speeds, e.g. by belt drives from a motor. It will be appreciated that all this structure, together with a magnetron for delivering the microwave power, will be positioned below the cavity but within the oven outer casing which is not shown in the drawings.
A forced flow of hot air is passed through the cavity simultaneously with the application of microwave power, so that food items placed on the tray 104 are subjected both to hot air and microwave power. FIG. 12, which is similar to FIG. 9, shows the hot air inlets and outlets in the back wall 96, as the latter is viewed from the front of the oven. The back wall 96 has two vertically elongated panels, each having groups of inlets 110 through which hot air is forced by a fan to enter the cavity. Having passed over the food items, the air leaves the cavity through the circular air outlets 112. The air is then forced over an electric resistance heating element (disposed in a compartment behind the rear wall 96) before being re-circulated through the inlets 110 and the cavity. The lines having arrows in FIG. 12 depict the air flow diagrammatically, it will be appreciated that the hot air is forced forwardly into the cavity from the inlets 110 before being drawn back to the outlets 112. It will also be appreciated that the cavity has a moisture vent, for example in the back wall 96.
In use, the turntable rotates about a central vertical axis, the underside of the tray 104 engaging the rollers 106. It will be appreciated from the foregoing description of the various embodiments of an oven in accordance with the invention that the cavity in each embodiment is a multi-mode cavity with a large number of resonances. Thus, the magnetic pattern of each cavity is complex and continuously changing due to driver member 14 (FIG. 2). Driver member 14 is a mode stirrer which couples to different resonant modes in the cavity. This and other adaptabilities and capabilities of the invention will be understood by those skilled in the art from the description herein as well as through experience with the disclosed embodiments and obvious variations thereof. | A microwave oven has a magnetron which launches microwave power into a cavity of the oven through an aperture in the base of the cavity. A metal tray, which may be a shelf or a rotatable turntable is supported above the aperture in a predetermined disposition so that the oven when devoid of food presents a poor power match with the magnetron in terms of effectiveness of power transfer from the magnetron into the oven cavity. As a result, the dielectric load of food items placed in the oven determines the power coupled to the loaded oven from the magnetron and the power transfer automatically increases in proportion to the dielectric food load in the oven. A forced hot air system blows hot air through the cavity, so that food items on the tray are cooked by the simultaneous application of microwave power and the hot air. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to an improved quench system and method for use in spinning multifilament synthetic fiber. More particularly, the system and method use a fog in the quench stack in combination with a flow of air.
By fog is meant fine particles of fluid, such as water suspended in air, specifically excluding fluid such as water droplets not suspended in air. This fog can be mechanically produced with an airless spray nozzle (atomizer) to atomize fluid such as water. Such an airless spray nozzle is disclosed in U.S. Pat. No. 3,366,721 hereby incorporated by reference. By fluid is meant any fluid which can absorb a great deal of heat, such as by the latent heat of vaporization of water or possibly liquid gases. Fluid also means mixtures of water with other fluids beneficial to fibers, such as finishes.
Although it is known to use flowing air to quench freshly spun filaments, and it is known to use airless spray fog or colloidal suspension of fluid, such as water (U.S. Pat. No. 3,366,721) alone to quench filaments, the combination is not taught. Each of these methods when used alone is uneconomical in capital investment or require high flow rates causing filament motion, undesirable for reasons given below.
Because a large volume of air at high velocity is necessary to create the water spray, the prior art method of using flowing air and sprayed water from a compressed air spray nozzle to quench filaments creates great turbulence of the filaments in the quench stack causing at worst filaments fusing together, or at best slight imperfections where the filaments touch or brush one another in the quench stack. Also, turbulence can cause denier variation. These fusions and even denier variation or slight imperfections then cause major problems in subsequent continuous processing of continuous filaments as they break, slough, or wrap on rolls in the drawing, twisting, texturing or like equipment.
Use of steam to condition fiber in the quench stack is also known, but does not utilize the latent heat of vaporization to cool the filaments which is available by use of fog.
Also, use of sprays of water droplets on the yarn is known but cause undesirable non-uniformities along the filament. In fact, such nonuniformity is used to intentionally create weak spots or to create crinkled fiber.
SUMMARY OF THE INVENTION
In the broad concept, the improved method of this invention is to quench freshly spun synthetic multifilament fibers in a quench stack using fog and air comprising spinning synthetic multifilament fiber from its molten polymer through a spinnerette then into a quench stack, introducing flowing air into the quench stack, then introducing fluid, such as water, in the form of fog generated from an airless atomizer into the quench stack along with the flowing air, controlling the air flow, and controlling the formation of the fog, to quench the freshly spun fiber.
A preferred method is to quench freshly spun fibers in a quench stack using air and fog and comprises spinning fiber from its molten polymer through a spinnerette into a quench stack and quenching the freshly spun fiber in the quench stack first with flowing air and then air and fluid, such as water in the form of fog generated from an airless atomizer, and taking up the fiber on a wound package, while controlling the air flow, and controlling the rate of formation of the fog. The atomizer nozzle can be preferably from about 4 to about 8 feet from the spinnerette. Preferably the fibers are from a synthetic polymer. Also, it is preferred to provide one nozzle for each two bundles of multifilament per stack. The air flow is preferably controlled to supply from about 0.01 to 0.15 standard cubic feet per minute per pound polymer per minute and the formation of fog is preferably controlled by atomizing water at a rate of from about 2 ounces of water per minute per pound of polymer per minute to 4.5 ounces of water per minute per pound of polymer per minute at a pressure of about 400 to 720 psi at the nozzle of the atomizer. The nozzle is more preferably located about 6 feet below the spinnerette. By use of this invention, a spinning and quench system designed for high throughput feeder yarn for staple can be converted to produce high quality feeder yarn for continuous filament processing at high throughput rates. The system uses the latent heat of vaporization to obtain a high degree of quenching. The fiber emerging from the interfloor tube has been measured at 20° C. compared to 35° to 40° C. for conventional quench systems.
The quench system of this invention for spinning multifilament fiber, preferably synthetic, using fog and air in a quench stack comprises a spinnerette for spinning synthetic fiber into a quench stack, preferably a cross-flow quench stack, a nozzle for airless atomizing water into fog, the nozzle preferably being located four to eight feet, more preferably, six feet below the spinnerette introducing fog into the quench stack, means for supplying a flow of air to the quench stack, means to exhaust the air flow from the quench stack, means to supply water to the nozzle, means to receive and remove any excess water droplets in the quench stack, means to control the air flow, and means to control the pressure of the water supply to the nozzle. The spinnerette is located at the entrance of the quench stack, while the means for supplying air, means to receive and remove any excess water droplets, means to exhaust air and nozzle all communicate with the quench stack. The means to supply the water communicates with the nozzle. Both the means to control are operatively connected respectively to the air flow supply means and the water supply means. The nozzle atomizes and communicates with the quench stack at a point downstream from said means to supply air and so that no water droplets are formed to directly contact the fiber. The quenching of the fibers is due entirely to the effect of the fog in conjunction with the air flow. Preferably, one nozzle is provided for each two bundles of multifilament fiber per stack. This invention makes possible spinning high quality continuous filament yarn from equipment designed for high throughput staple feeder yarn by simply modifying the quench stack to add the airless atomizer type sprayer to create a fog in the quench stack. This permits a much lower rate of flow of moving air through the quench stack and creates much less filament motion. This reduced filament motion in turn permits practicable downstream continuous processing of the continuous filament yarn because of much fewer feeder yarn fusion points and imperfections where yarn filaments have bounced or contacted one another. Denier quality is also improved. In fact, in a practical application of this invention on a spinning and quench system designed for high throughput staple feeder yarn into a piddler can, it was impossible to take up the yarn from the quench stack onto an acceptable wound package unless the fog was used in conjunction with the flowing air in the quench stack. Without fog introduction into the quench stack, commercially acceptable wound packages were not possible at the high throughputs desired. At those throughputs air flow was so high it caused high filament fusion levels, and very soft, unstable packages that could not be handled normally without sloughs of yarn occurring. Also full size packages could not be wound because ridges, overgrowth and overthrows of yarn would form, causing package deterioration.
Distribution of the quench air in a typical operation is as follows: Fifty percent of the quench air passes across the filaments being quenched and out into the room. The remaining 50 percent is aspirated by the movement of the yarn into the narrow part of the quench stack called the interfloor tube. Of that, 15 percent passes entirely through the tube and exhausts at the lower end of the quench stack and 35 percent is removed by the exhaust system located along the interfloor tube. In other embodiments greater portions of quench air may flow into the room, up to nearly 100 percent.
The new quench system has the upper area (near the spinnerette) operating as a standard cross flow system with a normal air profile, i.e., lower velocity at the top increasing to higher velocity at the bottom. The lower portion acts as a co-current system with room air being introduced in annular manner near the top and being exhausted in an annular near the bottom of the interfloor tube. The co-current section has the airless atomizing jet or jets located near the top (below the air introduction point) for the injection of water (or other fluidized medium) under high pressure to form fog. The resulting water as fog and vapor (due to the heat of the polymer filaments vaporizing the suspended fine water particles) are removed with the air exhaust. The use of cooling air prior to contacting filaments with fog puts a tough skin on the filament surface. This avoids the prior art problem of non-uniformities, weak spots, and crinkling of the filaments. Condensation from the cooled interfloor tube is collected at the exit of the tube and drained off to prevent yarn spotting.
This invention offers the following advantages over the prior art:
a. Provides increased heat removal from the fiber during quenching.
b. Combines the best features from both cross flow and co-current flow quench systems.
c. Allows for higher throughputs than either above system is capable of.
d. Reduces amount of fused filaments and filament movement.
e. Increased yarn uniformity.
f. Reduces requirement for high energy consumption of conditioned air.
g. Improves package formation by reducing yarn growth after winding.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a schematic, partial cross section, side view showing a preferred embodiment of the quench system of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the figure molten polymer from extruder 1 flows through conduit 2 to be forced by pump 3 through spinnerette 5 in spin block 4. The filaments 12 of synthetic fiber are extruded into quench stack 6 which has monomer exhaust 7 and monomer exhaust ring 8. Cooling air enters through plenum 9 from source of air 10 and enters quench stack as shown by arrows 11 flowing across filaments 12 and out of quench stack 6 as shown by arrows 13. Some quench air is also drawn along with the moving filaments as shown by arrow 23. Room air may also be drawn along in quench stack 6 as shown by arrow 24. Filaments 12 then pass through fog 26 formed by atomizer 16 which receives high pressure water through pipe 15 from pump 14. Water is supplied from water source 22. Filaments then pass through the interfloor tube section shown as the narrowed section of quench stack 6. Interfloor tube exhaust 17 for air and water vapor then exhausts a portion of the air drawn along with the filaments through the interfloor tube as shown by arrow 27. Filaments then contact finish roll 18 and pass around and over separator roll 19 and godet roll 20 to be taken up in takeup means 21 which could be a winder or tow can. Droplets of water which may condense inside on quench stack 6 are caught by drip catchers 28. Water is removed through drains 33. Air may flow into interfloor exhaust 17 from either direction as shown by arrows 25.
Control for water pressure to the atomizer is by pressure control valve 29. Control for air flow is by controller 32 on fan motor 31 which powers fan 30.
EXAMPLE
Using the system and method described above, nylon 6 polymer, having properties shown in Table 1, was extruded through a 140 hole ("Y" shaped) spinnerette to a denier of about 6,000, and taken up as two ends of 3,000 denier, 70 filaments each, at a rate of about 76 pounds per hour per spinnerette. Spinning and quench conditions are shown in Tables 2 and 3. The atomizer was a Nordson having the specifications given in Table 4 and atomizing water was done as specified in Table 4. Take-up was by conventional Leesona 967 winders at 3,000 feet/minute using standard spin finish. Air in the takeup area was maintained at about 48% relative humidity and 72° F. The resulting yarn was subsequently drawn, textured, commingled and taken up as a carpet yarn sales package. The yarn had properties as shown in Table 5. Yarn was then made into small carpet samples equal in appearance and quality to presently commercial carpet.
Note the air flow rate is about one third of normal for preparation of nylon feeder yarn for making nylon staple yarn for carpet end use. Also, the comparative data in Table 3 show the fusion of filaments is improved by 800% by using fog in combination with flowing air.
TABLE 1______________________________________Properties of Nylon 6 Polymer Type 1 Type 2______________________________________Relative Viscosity 56 60Extractables, % 2.7 2.0Carboxyl ends, per 7.5 12 to 16milliequivalents of polymerAmine ends, per 47 72milliequivalents of polymer______________________________________
TABLE 2______________________________________Spinning Conditions______________________________________Extruder temperature 260° C.Extruder pressure 600 psigPump type 5.6 cc/rev.Pump rpm 55.2Block temperature 260° C.Exit polymer temperature 263° C.Filter pack type Screens______________________________________
TABLE 3______________________________________Quench ConditionsCross Flow Quench______________________________________Quench Air Temperature, °F. 65 Relative Humidity, % 65Air flow, cfm 400 Velocity 6o fpm avg.Monomer exhaust, vacuum Inches of water 2 to 4Fused filaments, % .007Comparative Data______________________________________Fused filaments, with water to atomizer off .056______________________________________
TABLE 4______________________________________Atomizer Specifications______________________________________Type Nordson, 16:1 drive pressure to output pressure ratioOrifice, inches .003Turbulence plate, inches .003Pressure, psig. 560Water flow, ouncesper minute per nozzle 3.84______________________________________
TABLE 5______________________________________Yarn Properties______________________________________Undrawn Type 1 Type 2Denier 3,000 3,120Ultimate Elongation, % 315 360Tenacity, grams/denier 1.1 1.7DrawnDraw Ratio 2.8 3.0Drawing Speed, fpm 5,000 6,000Denier 1,330 1,300Ultimate Elongation, % 53 52Tenacity, grams/denier 2.1 3.0Entanglements per meter 33 31Yarn breaks during .63 1.0drawing, per hourYield of yarn on packages 86.5 --versus yarn fromspinning, %______________________________________
INITIAL TRIALS
In initial trials of the use of fog in the quench stack combined with flowing air, a closed quench stack using co-current air flow was used. Several times, when operating the spinning and quenching at 45 pounds/hour of polymer throughput and otherwise standard conditions, as given above, cylindrical packages of nylon 6 yarn could not be taken up on conventional winders when the fog was not being introduced about 6 feet down the stack because the yarn being wound would expand and form ridges and slough off of the packages until winding failed. Introducing fog under the same conditions permitted normal winding of full size yarn packages. Increasing air flow without fog would have created much undesirable filament motion in the quench stack. Also, yarn produced with no fog as compared to yarn produced with fog introduced to the quench stack along with the flow of air was highly inferior in mechanical quality during subsequent processing. That is, the yarn produced with no fog had a great deal more imperfections and nonuniformities along the length of the filaments as shown by problems in drawing. One sample of yarn produced with fog had no wraps during subsequent drawing while an equal amount taken from partial packages of yarn quenched with no fog had 0.21 wraps per pound of yarn drawn. One sample produced without fog could not be drawn because it continually broke when drawn at the same conditions as yarn quenched with fog and flowing air.
Using ten samples of wound sales packages of each type of nylon 6 feeder yarn for carpet end-use, one set quenched with air only and the other set quenched with air and fog under otherwise identical conditions, a comparative evaluation of mechanical quality was made. The packages were evaluated objectively, visually. A value of 1 indicates no overthrown ends, no broken fils and no loops on the package. The inspectors were trained in ordinary daily quality control inspections. The standard for commercial yarn is 2. A value of 5 indicates very poor quality, and any value above 3.5 would be rejected and not sold. The trial average for packages of yarn produced with fog in the quench stack was 1.8. The trial average for packages of yarn produced without fog in the quench stack was 4.4. The yarn produced without fog made unacceptable packages and also would not pass through the standard tufting needles used to tuft carpet due to snags from yarn imperfections. | A quench system for spinning multifilament synthetic fiber using a fog in the quench stack is disclosed. The system and method comprise
a. spinning synthetic multifilament fiber from the molten synthetic polymer through a spinnerette into a quench stack,
b. quenching the freshly spun fiber in the quench stack with a combination of flowing air and airless atomized water in the form of a fog, and
c. taking up the fiber onto a wound package,
d. while controlling the air flow, controlling the formation of the fog, and removing any excess water droplets formed in the quench stack. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid crystal display unit and, more particularly, to an arrangement and connection of IC chips that define a drive circuit for the display unit.
2. Description of the Prior Art
Recently, pocket-size computers and portable computers have been developed. Such a computer often has a liquid crystal display unit which is defined by a liquid crystal multi-dot display element and a drive circuit for driving the display element. The liquid crystal multi-dot display element generally has a plurality of dots aligned in a matrix format, enabling the display of various characters and symbols through on/off control of the dots. The drive circuit for such a display is formed by a plurality of IC chips, such as LSI chips. The liquid crystal multi-dot display element therefore requires numerous terminals, in the order of hundreds, which are aligned along the side of the element with a predetermined narrow pitch. The drive circuit also has a corresponding number of terminals which are electrically connected to the display element terminals.
According to the prior art, the LSI chips are mounted on a circuit board made of a non-flexible hard material and, therefore, it is necessary to provide a relatively large space for installing the circuit board at a position neighboring the multi-dot display element. This results in a bulky liquid crystal display unit.
Furthermore, according to the prior art, the circuit board is provided with numerous terminals aligned with a predetermined pitch, so that when the circuit board is placed at its position adjacent the multi-dot display element, the terminals on the circuit board can be electrically connected to the corresponding terminals on the display element. However, since the terminals on the circuit board and display element are aligned within a narrow space, the positioning of the circuit board is very difficult. If the circuit board moves a little, the terminals on the circuit board may not be connected to the proper terminals on the display element.
Moreover, according to the prior art, the terminals on the circuit board and those on the display element must be formed with high accuracy. Otherwise, some terminals may fail to connect with the corresponding terminals, even if the circuit board is positioned properly.
SUMMARY OF THE INVENTION
The present invention has been developed with a view to substantially solving the above described disadvantages and has for its essential object the provision of a liquid crystal display unit wherein an improvement is made to an arrangement and connection of IC chips that define a drive circuit for the display unit.
It is also an essential object of the present invention to provide a liquid crystal display unit wherein the IC chips for the driving circuit can be installed in a narrow space adjacent to the display unit.
It is a further object of the present invention to provide a liquid crystal display unit which is compact in size and can readily be manufactured at low cost.
In accomplishing these and other objects, an arrangement of a liquid crystal display unit according to the present invention comprises a display panel having a plurality of terminals, a plurality of flexible films made of electrically non-conductive material and an LSI chip carried on each flexible film. A plurality of electrodes are deposited on the film, and the films are provided in association with the display panel so as to electrically connect the LSI chip with the terminals.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the present invention will become apparent from the following description taken in conjunction with preferred embodiments thereof with reference to the accompanying drawings, throughout which like parts are designated by like reference numerals, and in which:
FIG. 1 is a perspective view of a liquid crystal display unit according to a first embodiment of the present invention;
FIG. 2 is a side elevational view of the liquid crystal display unit of FIG. 1;
FIG. 3 is a circuit diagram of an electrode pattern employed in the liquid crystal display unit of FIG. 1;
FIG. 4 is a top plan view of a printed circuit film employed for the first embodiment showing a pattern of electrodes extending from an LSI;
FIG. 5 shows a pattern of common electrodes;
FIG. 6 shows the pattern of FIG. 4 overlapped with that of FIG. 5 so as to effect the electric connection between certain terminals on the electrode pattern of FIG. 4 and those on the electrode pattern of FIG. 5;
FIG. 7 is a perspective view of a liquid crystal display unit according to a second embodiment of the present invention, but particularly showing parts which differ from those of FIG. 1;
FIG. 8 is a side elevational view of the liquid crystal display unit of FIG. 7;
FIG. 9 is a circuit diagram of an electrode pattern employed in the liquid crystal display unit of FIG. 7;
FIG. 10 is a perspective view of a liquid crystal display unit according to a third embodiment of the present invention, particularly showing the rear side thereof; and
FIG. 11 is a cross-sectional view taken along a line XI--XI shown in FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a liquid crystal display unit according to a first embodiment of the present invention is shown. The liquid crystal display unit has a liquid crystal multi-dot display panel 2 defined by two layers of transparent plates, such as glass plates, and a liquid crystal arrangement (not shown) sandwiched therebetween. Display panel 2 can be viewed in the direction indicated by an arrow. Extending from the liquid crystal arrangement are a plurality of terminals 3 which are aligned along a tiered edge.
A drive circuit for driving the liquid crystal arrangement is formed by IC chips, such as LSI chips 4, each of which is carried by a flexible film 6. It is to be noted that each LSI chip 4 is a so-called film carrier type and is firmly carried on a separate sheet of film 6, through a known step, such as an inner bonding step. Thus, the LSI chip 4 projects above and below the flexible film 6, as best shown in FIG. 2. Flexible films 6 are positioned side-by-side and located immediately under display panel 2. Each flexible film 6 has a predetermined pattern of electrodes 8 and 10 deposited thereon which extend from the LSI chip 4. Electrodes 8 are aligned along one side of film 6 and are provided for sending signals to the liquid crystal arrangement in a manner which will be described later. Electrodes 10 are deposited at different distances from the LSI chip 4, and are provided for receiving electric power and various data signals from a bus structure described below.
The bus structure, according to the first embodiment, is formed by three parallel line electrodes 12 deposited on an elongated flexible film 14. Each line electrode has widened plates 12a disposed with a predetermined pitch. The widened places 12a on three lines 12 do not align with each other, but are in an offset relation. Flexible film 14 is provided on the aligned flexible films 6 such that widened places 12a are electrically connected to electrodes 10 on films 6 through a suitable connecting means, such as bonding or soldering. Accordingly, short electrodes 10 on films 6 are connected to each other. Similarly, intermediate electrodes 10 and long electrodes 10 are also connected to each other, respectively.
An elongated unidirectional conductive rubber sheet 16 is provided between an array of electrodes 3 on display panel 2 and an array of electrodes 8 on flexible film 6. Rubber sheet 16 has such a feature that it permits electric conduction only in its thickness direction T. Accordingly, electrodes 3 are electrically connected to corresponding electrodes 8.
Provided under the flexible films 6 is a base plate 20 which has a groove 22 formed therein so as to receive the projecting portion of each LSI chip 4.
Referring to FIG. 2, flexible films 6 provided with flexible film 14 and rubber sheet 16 are fixedly supported between panel 2 and base plate 20 by U-shaped holders 13 (only one is shown in FIG. 2) which are pressure fitted at opposite ends of the display unit. It is to be noted that the end portion of elongated flexible film 14, particularly the side deposited with electrodes 8, are uncovered, so as to permit the external electric connection to electrodes 8. The signals transmitted through electrodes 8 are applied to LSIs 4, each of which produces a particular signal for driving particular segment or segments. The signal produced from each LSI 4 is transmitted from terminals 8 through rubber sheet 16 to terminals 3 and further to the liquid crystal arrangement.
Referring to FIG. 3, a circuit diagram of the electric connection between the bus structure and LSIs 4 is shown. As apparent from FIG. 3, the alignment of terminals A, B and C of LSI chips 4 is the same through all the LSI chips 4. Thus, the same type of LSIs 4 are employed.
In the embodiment shown in FIGS. 1 through 3, there are five terminals 8 extending from LSI chip 4 for connection with the liquid crystal arrangement, and three terminals 10 for connection with the bus line. The number of the terminals is not limited to the above-described embodiment but can be any other number. For example, according to one model of LSI, there are sixty-four terminals 8 for connection with the liquid crystal arrangement and eight terminals 10 for connection with the bus lines. An electrode pattern on film 6 for the above-described model of LSI is shown in FIG. 4, and an electrode pattern on film 14 for the bus structure employed therefor is shown in FIG. 5. As indicated in FIG. 5, additional lines 13 are provided on film 14 for connection with the neighboring LSI chips. FIG. 6 shows a manner in which the electrode pattern of FIG. 4 is overlapped with the electrode pattern of FIG. 5.
Furthermore, the flexible films, each carrying LSI chip 4, may be provided on the other side (not shown) of panel 2, in a manner similar to that shown in FIG. 10.
Referring to FIG. 7, a liquid crystal display unit according to a second embodiment of the present invention is shown. When compared with the first embodiment, the electrode patterns for the electric connection between LSI chips 4 and the bus structure is different. Electrodes 10' are so aligned that, when films 6 are aligned to form an array of terminals 8, as shown in FIG. 7, the terminal portions 10', as well as the terminal portions 12', for effecting the electric connection, e.g., by the deposition of solder beads, are aligned in a straight line. This arrangement is accomplished by extending the bus lines in S-formation. When this arrangement is employed, films 6 can be smaller than that of the first embodiment shown in FIG. 1.
Referring to FIG. 8, the liquid crystal display unit of the second embodiment is not provided with the base plate 20. Thus, U-shaped holders 13 are pressure fitted to hold film 6 and panel 2 with the unidirectional conductive rubber sheet 16 inserted therebetween.
Referring to FIG. 9, a circuit diagram of the electric connection between the bus structure and the LSIs 4 is shown. As apparent from FIG. 9, the alignment of terminals A, B and C of LSI chips 4 is either ABC or CBA and, therefore, two different types of LSIs 4 are employed.
Referring to FIG. 10, a bottom view of a liquid crystal display unit according to a third embodiment of the present invention is shown. FIG. 11 shows a cross sectional view taken along a line XI--XI shown in FIG. 10. When compared with the previous embodiments, the bus structure is formed by a hard circuit board 14'. Furthermore, in this embodiment, instead of using the unidirectional conductive rubber and holder 13, electrodes 8 and films 6 are directly connected to electrodes 3 of panel 2 through a suitable known method, such as a heat seal method. Moreover, instead of soldering, electrodes 10 and electrodes 12 can be connected also through a heat seal method.
According to the present invention, since the films 6 are separated from each other, the positioning of each film 6 can be accomplished easily so that terminals 8 on every film 6 can be properly connected to the corresponding terminals 3 on panel 2.
Furthermore, since films 6 are formed by flexible material, they can be provided in the least necessary space, resulting in a compact size display unit.
According to the second embodiment, since the electric connection between electrodes 10 and electrodes 12 can be accomplished along a straight line, film 6 can be very small in size.
According to the third embodiment, since electrodes 8 and corresponding electrodes 3 are directly connected to each other, the electric connection therebetween can be accomplished with high reliability.
Furthermore, when the electric connections are accomplished through heat seal method, there will be hardly any heat expansion or heat contraction of film 6, resulting in the simple positioning of the films 6.
Although the present invention has been fully described with reference to several preferred embodiments, many modifications and variations thereof will now be apparent to those skilled in the art, and the scope of the present invention is therefore to be limited not by the details of the preferred embodiments described above, but only by the terms of the appended claims. | An arrangement of a liquid crystal display unit includes a display panel having a plurality of terminals, a plurality of flexible films made of electrically nonconductive material and an LSI chip bonded into each flexible film. A plurality of electrodes are deposited on each film, with the films being provided in association with the display panel to electrically connect each LSI chip with the display panel terminals. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an improved batch-type method of annealing large coils of silicon steel for magnetic purposes, and more particularly to such an annealing method utilizing a furnace of the type taught in U.S. Pat. No. 3,588,305.
2. Description of the Prior Art
As used herein and in the claims, the term "silicon steel" relates to an alloy, the typical composition of which by weight percent falls within the following:carbon 0.060% maximumsilicon 2-4%sulfur orselenium 0.03% maximummanganese 0.02-0.4%aluminum 0.04% maximumiron balance
At the present time, there is a great demand for silicon steels fo sheet gauge for magnetic uses such as lamination cores for transformers and the like. While not intended to be so limited, for purposes of an exemplary showing the present invention will be described in terms of the production of cube-on-edge oriented silicon steel. It will be understood that cube-on-face oriented silicon steel, for example, can be produced by the present invention.
In general, the production of cube-on-edge oriented silicon steel includes the steps of hot rolling ingots or slabs of a suitable composition to an intermediate gauge, pickling and heat treating the hot-rolled product, cold rolling to final gauge in one or more cold rolling stages (with intermediate anneals if in multiple stages), decarburizing, coating with an annealing separator and subjecting the steel to a final anneal consisting of a primary grain growth stage and a secondary grain growth stage. The present invention is directed to the final anneal and is not limited to the various processing steps practiced prior to the final anneal. It is during the final anneal that the desired orientation is achieved. In cube-on-edge oriented silicon steel the body-centered cubes making up the grains or crystals are oriented in the cube-on-edge position, designated (110)[001] in accordance with Miller's indices.
The development of the cube-on-edge orientation is achieved by the grain boundary phenonemon which requires the presence of a grain growth inhibitor at the grain boundaries during the primary grain growth stage of the final anneal. Manganese sulfides and manganese selenides are typical inhibitors formed for this purpose. The manganese and sulfur or selenium content of the initial melt may be such as to assure the presence of manganese sulfides or manganese selenides at the grain boundaries during the primary grain growth stage of the final anneal. On the other hand, as taught in U.S. Pat. No. 3,333,991, 3,333,992 and 3,333,993 sulfur, selenium or compounds thereof may be provided in the annealing atmosphere or in the annealing separator. Similarly, sulfur, selenium or compounds thereof may be made available at the surfaces of the steel during a decarburizing anneal prior to the final anneal. In any event, the sulfur or selenium will defuse to the grain boundaries forming inhibitors during the primary grain growth stage of the final anneal. As is known in the art A1N may also be used as a grain growth inhibitor.
In the usual prior art practice, coils of silicon steel weighing from 10,000 to 15,000 pounds were annealed in dry hydrogen in a muffle or box at a temperature of about 2200°F.
More recently, semi-continuous annealing furnaces have been developed for the annealing of silicon steel. U.S. Pat. No. 3,756,868 teaches such a furnace comprising a massive two-level structure wherein individual cars, each carrying a coil, are continuously caused to enter the furnace through a vestibule and exit the furnace through the same vestibule. The furnace itself comprises various sections including an initial heat section, an initial soak section, a final heat section, a final soak section and some five cooling sections. Each car carrying a coil to be annealed enters the vestibule which is then purged by nitrogen gas. The vestibule is then filled with hydrogen gas and the car proceeds through the remainder of the furnace, having a hydrogen gas atmosphere therein.
At the end of the furnace, the car and coil to be removed reenters the vestibule which is again purged with nitrogen prior to removal of the car therefrom.
In U.S. Pat. No. 3,778,221 a somewhat similar arrangement is shown. In this patent a semi-continuous annealing furnace is taught having an entrance vestibule, an initial heat section, a transfer station, an initial soak section, a final heat section and a final soak section followed by some five cooling sections and a separate exit vestibule. In accordance with the teachings of this patent, again cars pass continuously through the furnace, each car bearing a coil of silicon steel. A car carrying a coil to be annealed enters the entrance vestibule which is evacuated to remove gaseous impurities and air therefrom. The entrance vestibule is then charged with hydrogen followed by a second evacuation. The initial heating section of the furnace is also evacuated and separated from the remainder of the hydrogen-filled furnace by the transfer station. As a car is about to leave the furnace, it enters the exit vestibule which is then evacuated. Following evacuation, the vestibule is filled with nitrogen or air and opened for removal of the car and coil.
By virtue of the increased demand for oriented silicon steel, it would be advantageous to the steel manufacturer to be able to anneal the silicon steel in very large coils ranging from 30,000 to 40,000 pounds or more per coil. The present invention is directed to the batch-type annealing of such very large coils in a furnace of the type taught in U.S. Pat. No. 3,588,305. Typical prior art procedures involving a muffle or box were not intended for the annealing of such very large coils. The more recent semi-continuous annealing procedures require larger and more complex equipment utilizing a more complex annealing process.
SUMMARY OF THE INVENTION
The batch-type method of the present invention for annealing large coils of silicon steel for magnetic purposes is directed to the use of an annealing furnace of the type taught in U.S. Pat. No. 3,588,305. As will be described hereinafter, such an annealing furnace comprises an outer enclosure surrounding an insulated heating chamber in which the coils are supported. The furnace is capable of subjecting the coils both to a desired atmosphere and to a vacuum.
The anneal in question is the final anneal during which the desired magnetic properties of the silicon steel are developed. As indicated above, the processing of the silicon steel prior to the final anneal may be conventional and may be accomplished by any appropriate routing known in the art. As is customary, the silicon steel will be provided with an annealing separator, again as is well known in the art.
The coils to be annealed are placed on a car and transferred into the heating chamber of the furnace and the furnace is closed and sealed. A vacuum is drawn within the furnace enclosure and the heating chamber to remove air therefrom. This is followed by back-filling with a desired non-oxidizing annealing atmosphere, such as hydrogen. Throughout the heat-up, soak and cooling portions of the anneal, the annealing atmosphere is circulated through the furnace, exiting the furnace to a flare stack or appropriate recovery means. The heating elements of the furnace are then energized and the coils are brought to a temperature of about 2200°F. (1204°C.) and are caused to soak at that temperature for an appropriate length of time. Following the soak step, the heating elements of the furnace are de-energized and the coils are cooled in three steps. Accordingly, the coils are first subjected to an initial slow cooling step at a maximum rate of from about 62.5°F. to about 83°F. (from about 34.6°C. to about 46.1°C.) per hour to a temperature of about 1700°F. ( 927°C). Thereafter, the coils are subjected to an intermediate cooling step at the maximum rate of from about 19.8°F. to about 26.4°F. (from about 11.0°C. to about 14.7°C.) per hour to a temperature of about 1225°F. (663°C.). The coils are then subjected to a final fast cooling step at the maximum rate of from about 162.5°F. to about 243.8°F. (from about 90°C. to about 135.4°C.) per hour to a temperature of about 250°F (121°C). At this time, a vacuum is drawn within the enclosure and the heating chamber to remove the annealing atmosphere therefrom. Upon removal of the annealing atmosphere, the furnace enclosure and heating chamber is back filled with nitrogen, whereupon the furnace may be opened and the coils removed therefrom.
When a high permeability cube-on-edge oriented silicon steel is desired, the silicon-steel coils containing A1N as the grain growth inhibitor, substantially the same process may be followed including the step of soaking the coils at 1200°F. (649°C.) for about 6 hours prior to the soaking step at 2200°F. (1204°C.). When 30,000 pound coils are being treated, the upper ends of the above noted maximum cooling rate ranges may be used. Similarly, when 40,000 pound coils are used, the lower ends of the above noted maximum cooling rate ranges are employed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a semi-diagrammatic elevational view, partly in cross-section of a furnace of the type described in U.S. Pat. No. 3,588,305 and utilized in the process of the present invention.
FIG. 2 illustrates graphically the process of the present invention, plotting minimum time in hours and temperature in degrees Fahrenheit.
FIG. 3 illustrates graphically another embodiment of the process of the present invention, again plotting minimum time in hours and temperature in degrees Fahrenheit.
FIGS. 4 and 5 are similar to FIGS. 2 and 3 and illustrate graphically yet other embodiments of the process of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For a complete understanding of the process of the present invention, reference is first made to FIG. 1 wherein a furnace of the type taught in U.S. Pat. No. 3,588,305 is semi-diagrammatically illustrated. In FIG. 1, the furnace is generally indicated at 1 and is shown mounted on an appropriate foundation 2. The furnace comprises an outer enclosure 3. While not so limited, the enclosure 3 may be double-walled, having outer wall 3a and inner wall 3b so that water may be circulated between the walls to cool and control the temperature of the outer enclosure. When the enclosure is water cooled, appropriate water inlet and outlet means (not shown) are provided, as is well known in the art. At its forward end, the enclosure is provided with a door 4 which may also be double-walled for water cooling. Means (not shown) may be provided to raise and lower the door between open and closed positions, again as is well known in the art.
Within the enclosure 1 there is a heating chamber generally indicated at 5. The chamber 5 comprises a top wall 6, side walls (one of which is shown at 7) and an end wall 8. This much of the heating chamber is appropriately supported within the furnace enclosure 1 by means not shown. The support means for this portion of the heating chamber may, themselves, be wheeled so as to ride upon rails enabling this portion of the heating chamber to be removed from the enclosure 1 for repair or the like.
A car, generally indicted at 9, is provided with a plurality of wheels, some of which are shown at 10, adapted to ride upon two or more rails (one of which is shown at 11). The car 9 is made up of four sections 9a through 9d, appropriately hooked together so that the entire car 9 may act as a single unit. The car 9, as will be evident from FIG. 1, constitutes the bottom of the heating chamber 5. Car section 9a carries an upstanding wall 12 comprising the forward wall of heating chamber 5. When the car 9 is fully within the enclosure 1 it will be noted that it completes the heating chamber 5. The front wall 12, rear wall 8, top wall 6 and side walls (one of which is shown at 7) of the heating chamber 5 may be made of or lined with any appropriate ceramic fiber refractory material as is well known in the art. The upper surface of the car 9 is also covered with an appropriate ceramic fiber refractory material.
For purposes of loading the heating chamber 5, the door 4 of the outer enclosure 1 can be shifted to its open position and the car 9 may be removed from the furnace and located upon a transfer carriage fragmentarily shown at 13. The carriage 13 rides on rails, one of which is shown at 14. The carriage, itself, is provided with transverse rails (one of which is shown at 13a) adapted to align with the rails 11 and to receive the wheels 10 of car 9. The car 9 then, via transfer carriage 13, may be taken to a loading station to receive coils to be annealed or to an unloading station to remove coils which have been annealed.
In FIG. 1 the car 9 is illustrated as carrying four silicon steel coils 15 through 18 mounted upon base plates 19 through 22, respectively. The base plates, themselves, are horizontally oriented and spaced upwardly from the insulative material on the upper surface of car 9 by support means 23.
Beneath the base plates 19 through 22 and above the ceramic fiber refractory material covering the top surface of the car 9 there is a plurality of heating elements 24 following a sinuous path between the supports 23. The inside surfaces of top wall 6 and the side walls of the heating chamber 5 may also be provided with heating elements (not shown) mounted thereon.
The interior of the outer enclosure 3 may be connected to an appropriate vacuum source by a conduit 25 controlled by a valve means 26. In this way, the furnace outer enclosure 3 and the heating chamber 5 may be evacuated. It will be understood by one skilled in the art that communication between the outer enclosure 3 and heating chamber 5 is accomplished either by passages in the heating chamber formed for that purpose, or by spaces between the bottom of the chamber (car 9) including front wall 12 and the remainder of the heating chamber, or both. Via conduit 27 controlled by valve 28 or conduit 29 controlled by valve 30 various desired atmospheres may be introduced into the outer enclosure 3 and heating chamber 5. Atmospheres so introduced will circulate through the outer enclosure and the heating chamber, exiting the outer enclosure via conduit 31, controlled by valve means 32. The conduit 31 may lead to an atomosphere recovery means or a flare stack, as is well known in the art.
To increase circulation within the heating chamber 5 and the outer enclosure 3, fans indicated at 33 through 36 may be provided. Motor means for the fans 33 through 36 are located exteriorly of the outer enclosure 3, as at 37 through 40, respectively. The fans 33 through 36 serve to draw atmosphere from the heating chamber 5 and return it to the outer enclosure 3. In the exemplary embodiment the fans are illustrated as being located at the top of the furnace. Alternatively, the fans could be located at one or both of the furnace sides. To further increase circulation of atmosphere within the heating chamber, the side walls of the chamber may be provided with automatically actuated bungs. Such bungs are illustrated in side wall 7 at 41 through 44.
As indicated above, the car 9 normally operates as a single unit. However, it is made up of the separate car sections 9a through 9d which may be detached from each other for purposes of repair or the like.
As is taught in the above mentioned U.S. Pat. No. 3,588,305, in large installations a number of furnaces of the type illustrated in FIG. 1 may be employed with the transfer cart 13 serving them. The operation of the furnaces may be coordinated for purposes of loading, unloading and annealing by computer means which will govern the various annealing operations including times and temperatures. The computer means will control the opening and closing of the various valves 26, 28, 30 and 32 as well as turning on and off the heating elements within heating chamber 5. The actual control means for all of these elements, the number of furnaces used and the like, do not constitute a part of the present invention.
In accordance with the present invention, silicon steel is processed by any appropriate routing so as to produce during the final anneal an end product having the desired orientation utilizing sulfur, selenium or compounds thereof as a grain growth inhibitor. In the exemplary embodiment first to be described wherein the final product has a cube-on-edge orientation, the silicon steel is coated with an annealing separator such as magnesia, or the like, and is formed into coils weighing about 30,000 pounds. As indicated above, the particular routing followed prior to the final anneal does not constitute a limitation on the present invention.
In the description to follow of the annealing process reference is made to FIGS. 1 and 2. FIG. 2 illustrates the annealing process in graph form, plotting minimum times in hours and temperature in degrees Fahrenheit.
The coils, having been coated with an appropriate annealing separator, are located upon the base plates 19 through 22 and the car is located within the furnace outer enclosure 3, thereby completing the heating chamber 5. The door means 4 of the outer chamber is closed and the annealing procedure is ready to begin.
The first step of the procedure is to draw a vacuum within the furnace 1 to a level of about 500 microns. The vacuum is drawn through conduit 25 controlled by valve 26. All of the remaining valves 28, 30 and 32 are closed. The drawing of the vacuum will take a minimum of about 60 minutes. When the desired level of vacuum is reached the valve 26 is closed and the vacuum is held for a minimum of 2 minutes with all furnace valves closed. The purpose of this step is to remove all air from the furnace enclosure 3 and heating chamber 5. This step eliminates flushing of the enclosure 3 and heating chamber 5 with nitrogen or some other appropriate atmosphere.
At this point, with all other valves closed, valve 28 in conduit 27 is opened and hydrogen is backfilled into the outer enclosure 3 and heating chamber 5. The hydrogen is pure hydrogen at ambient temperature and fills the outer enclosure and heating chamber to a pressure of about 750 mm of mercury. This step takes a minimum of about 15 minutes. It will be understood by one skilled in the art that while the present process will be described in terms of using pure hydrogen as an annealing atmosphere, other annealing atmospheres such as hydrogen-nitrogen mixtures or vacuum annealing may be used. The use of other annealing atmospheres or a vacuum may require adjustment of other operating parameters, as will be understood by one skilled in the art.
At this point, valve 32 is opened in conduit 31 leading to the atmosphere recovery means or flare stack and hydrogen, still entering via conduit 27, is circulated through the outer enclosure 3 and heating chamber 5 at the rate of about 1100 cubic feet per hour. This circulation rate of the hydrogen is maintained throughout the heat-up step of the anneal. The circulating hydrogen removes the moisture from the annealing separator during this circulation step and the following heat-up step.
Once the hydrogen circulation has been established for about 10 minutes, the electrical heating elements of the furnace are turned on so as to heat the silicon steel coils at the rate of about 60°F. (34°C.) per hour until a temperature of about 2175°F. (1190°C.) is reached. The heat-up step takes a minimum of about 1850 minutes (30 hours and 50 minutes) as shown in FIG. 2 and on average will take about 34 hours and 10 minutes.
Once the heat-up step has been accomplished, the circulation of the annealing atmosphere or hydrogen in the outer enclosure 3 and heating chamber 5 will be reduced to about 400 cubic feet per hour. This flow rate will be maintained during both the soak step and the cooling steps. The heating elements are so controlled as to soak the silicon steel coils 15 through 18 at a temperature of 2200°F. (1204°c.) for a minimum of 1440 minutes (24 hours) as shown in FIG. 2.
Following completion of the soak step, the power is shut off to the electrical heating elements within the heating chamber and a three stage cooling procedure is started. Accordingly, the first step is an unassisted, slow cooling step which continues until the coils 15 through 18 reach a temperature of about 1700°F. (927°C.) and requires a minimum time of about 360 minutes (6 hours). This represents a maximum cooling rate of approximately 83°F. (46°C.) per hour.
When the coils reach approximately 1700°F. (927°C.) an intermediate cooling step is initiated. The bungs 41 through 44 of the heating chamber 5 remain closed and the fans 33 through 36 are turned on. The coils 15 through 18 are cooled to about 1225°F. (663°C.). This intermediate cooling step requires a minimum of about 1080 minutes (18 hours). This represents a maximum cooling rate of approximately 26.4°F. (14.7°C) per hour.
When the coils reach approximately 1225°F. (663°C.) and after a one minute hold to stabilize the furnace pressure, a final fast cooling step is initiated with fans 33 through 36 remaining on and bungs 41 through 44 open. Coils 15 through 18 are cooled to about 250°F. (121°C.) in a minimum time of about 4 hours, representing a maximum cooling rate of about 243.8°F. (135.4°C.) per hour.
The times given above for the cooling steps are minimum times as shown in FIG. 2. In practice, these three steps average approximately 420 minutes (7 hours), 1200 minutes (20 hours) and 360 minutes (6 hours), respectively, with average cooling rates of 71.4°F. (39.6°C.), 23.8°F. (13.2°C.) and 162.5°F. (90.3°C.) per hour, respectively.
When the coils reach the temperature of approximately 250°F. (121°C.) the bungs 41 through 44 are closed, valves 28 and 32 are closed (i.e. all valves are closed) and the fans 33 through 36 are turned off. This step takes a minimum of about 2 minutes. Thereafter, a vacuum is drawn by opening valve 26 in conduit 25. The vacuum is drawn to a level of about 500 microns. This step takes a minimum of about 50 minutes. Once the vacuum has been established, the valve 26 in conduit 25 is closed and the vacuum is held with all valves of the furnace closed for a minimum of about 2 minutes. These vacuum and hold steps cause all of the hydrogen or other annealing atmosphere used to be removed from the outer enclosure 3 and heating chamber 5.
Next, valve 30 in conduit 29 is opened, backfilling the outer enclosure 3 and heating chamber 5 with nitrogen or an appropriate inert gas. The nitrogen is introduced until it attains a pressure of about 740 mm of mercury. This step takes approximately 15 minutes. Upon completion of the nitrogen backfill, the cycle is completed and the door means 4 of the furnace may be opened. The car 9 carrying coils 15 through 18 may be removed from the outer enclosure 3 onto the transfer car 13 to be taken to an appropriate unloading station for the annealed coils. The minimum time required for this annealing procedure is 5128 minutes (85 hours 28 minutes). It has been found that the average overall time for the annealing procedure is about 90 hours.
The various time and temperature milestones which are programmed for the computer means are developed to produce the desired final product. For example the size of the charge will have a bearing. Thus, if silicon steel of the type set forth in the previously described exemplary embodiment is annealed in accordance with the present invention in coils weighing 40,000 pounds (rather than 30,000 pounds), all of the milestones and procedural steps remain the same with the exception of the minimum times required for the three cooling steps and thus the maximum rates of these steps. This is shown in FIG. 3.
The initial slow cooling step from 2200°F. to 1700°F. (1204°C. to 927°C.) requires a minimum of about 480 minutes (8 hours representing a maximum cooling rate of about 62.5°F. (34.6°C.) per hour. The intermediate cooling step from 1700°F. to 1225°F. (927°C. to 663°C.) takes a minimum time of about 1440 minutes (24 hours) at a maximum rate of about 19.8°F. (11.0°C.) per hour. After a one minute holding period to stabilize the furnace pressure prior to opening the bungs, the final fast cooling step from 1225°F. to 250°F. (663°C. to 121°C.) requires a minimum time of about 360 minutes (6 hours) at a maximum rate of about 162.5°F. (90.3°C.) per hour.
The times given above for the cooling steps are minimum times (as shown in FIG. 3). In practice these three steps average approximately 540 minutes (9 hours), 1560 minutes (26 hours) and 480 minutes (8 hours), respectively, with average cooling rates of 55.5°F. (30.8°C.), 18.3°F. (10.2°C.) and 122°F. (67.8°C.), respectively.
With 40,000 pound coils the minimum time required for the annealing procedure is 5728 minutes (95 hours, 28 minutes). It has been found that the average overall time for the annealing procedure is about 100 hours.
The exemplary annealing procedures thus far described are applicable without change for the annealing of cube-on-face oriented silicon steel provided with an appropriate annealing separator and coiled into 30,000 pound or 40,000 pound coils.
Depending upon the type of charge in the heating chamber, modifications may be required in the computer milestones. For example, when it is desired to make a high permeability cube-on-edge oriented silicon-steel and when the silicon steel contains A1N as the grain growth inhibitor, it is preferable to modify the above described annealing process as shown in FIG. 4. Again, 30,000 pound coils, having been coated with an appropriate annealing separator, are located upon base plates 19 through 22 on the car and are shifted within the heating chamber 5, after which the outer chamber is closed. A vacuum is drawn within the furnace 1 and is held therein in the same manner described above. After a holding period of at least 2 minutes the furnace is backfilled with hydrogen again in the same manner described above. This step will take a minimum of about 18 minutes.
At this point, valve 32 is opened in conduit 31 leading to the atmosphere recovery means or flare stack and a hydrogen-nitrogen mixture is circulated through the outer enclosure 3 and heating chamber 5. The nitrogen is circulated at the rate of about 900 cubic feet per hour and the hydrogen is circulated at the rate of about 300 cubic feet per hour. These circulation rates for the hydrogen and nitrogen are maintained throughout the two-stage heat-up and intermediate hold of the anneal, next to be described. This 3 to 1 nitrogen to hydrogen ratio is used during heat-up to preserve the A1N grain growth inhibitor.
Once the circulation for these gases has been established for about 10 minutes, the electrical heating elements of the furnace are turned on so as to heat the silicon steel coils at the rate of about 60°F. (34°C.) per hour until a temperature of about 1200°F. (649°C.) is achieved. This initial heat-up stage will require a minimum of about 900 minutes (15 hours). The coils are held at 1200°F. (649°C.) for a minimum of 360 minutes (6 hours). The purpose of this intermediate soak is to obtain a lower dewpoint (i.e. a dryer furnace atmosphere) prior to heating to higher temperatures. Thereafter, the temperature is increased at the same rate to about 2175°F. (1190°C.). This second stage heat-up will require a minimum of 975 minutes (16 hours, 15 minutes).
Once the first and second stage heat-up steps have been accomplished, including the intermediate temperature hold, the annealing atmosphere is changed to hydrogen only in the outer enclosure 3 and heating chamber 5 and will be circulated therein at a rate about 400 cubic feet per hour. This low rate will be maintained during both the soak step and the cooling steps. The heating elements are controlled so as to soak the silicon steel coils at a temperature of 2200°F. (1204°C.) for a minimum of 1440 minutes (24 hours) as shown in FIG. 4.
Following the soak step, the silicon steel coils are cooled in three steps substantially identical to those described above with respect to ordinary cube-on-edge silicon steel in 30,000 pound coils (see FIGS. 2 and 4) with the same maximum and average cooling rates. Once the coils attain a temperature of approximately 250°F. (121°C.) the same procedures will be followed as described in the previous exemplary embodiment, of 30,000 pound coils. The minimum time for the annealing of the A1N-containing 30,000 pound coils is 5516 minutes (91 hours, 56 minutes), the average overall time for the annealing procedure being about 96 hours.
When 40,000 pound coils of A1N-containing silicon steel are to be annealed to produce a cube-on-edge product, the preliminary and heat up steps will be the same as just described. The three step cooling procedures and steps that follow will be the same as those described above for 40,000 pound coils of ordinary silicon steel (see FIG. 5). The minimum time for the annealing of A1N-containing 40,000 pound coils is 6116 minutes (101 hours, 56 minutes), the average overall time being 106 hours.
In the procedures set forth above, the minimum times have been selected and programmed as a safeguard to assure that a minimum time is provided for each step as indicated. The rates associated with these minimum times are therefor maximum rates. The above noted average times are indicative of formal operating conditions. In practice, the times (including heat-up and cooling times) will vary slightly between furnaces and annealing cars and can additionally vary (as shown above) depending upon the weight of and the nature of the coils charged in the furnace.
Modifications may be made in the invention without departing from the spirit of it. | A batch-type method of annealing large coils of silicon steel for magnetic purposes in an annealing furance of the type comprising an outer enclosure surrounding an insulated heating chamber in which the coils are supported, the furnace being capable of subjecting the coils both to a desired atmosphere and a vacuum. The method comprises the steps of locating the coils to be annealed in the furnace heating chamber; drawing and holding a vacuum within the outer enclosure and heating chamber to remove air therefrom; backfilling with a desired non-oxidizing annealing atmosphere; circulating the annealing atmosphere through the outer enclosure and heating chamber; heating the coils to a temperature of about 2200°F. (1204°C.) and soaking the coils at temperature with continued annealing atmosphere circulation; subjecting the coils to an initial, slow, unassisted cooling step down to about 1700°F. (927°C.); subjecting the coils to an intermediate cooling step down to about 1225°F. (663°C) with the furnace fans on and the furnace bungs closed; subjecting the coils to a final fast cooling step down to about 250°F. (121°C.) with the furnace fans on and the furnace bungs open; drawing and holding a vacuum within the outer enclosure and heating chamber to remove the annealing atmosphere therefrom; backfilling with nitrogen and removing the coils from the furnace. When the silicon steel for magnetic purposes is to have a cube-on-edge orientation and contains Aln as the grain growth inhibitor, the coils may be held at 1200°F. (649°C.) for about 6 hours prior to heating them to 2200°F. (1204°C.) and the soaking step. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of and co-owned U.S. patent application Ser. No. 10/911,280, filed with the U.S. Patent and Trademark Office on Aug. 4, 2004 entitled “Method for Laying and Interlocking Panels”, now U.S. Pat. No. 7,065,935, which is a continuation of and co-owned U.S. patent application Ser. No. 09/609,251, filed with the U.S. Patent and Trademark Office on Jun. 30, 2000 entitled “Method for Laying and Interlocking Panels”, now U.S. Pat. No. 6,804,926, which is a continuation of PCT/DE00/00870, filed Mar. 22,2000 filed in Germany by the inventor herein, the specifications of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method for laying and interlocking panels, particularly via a fastening system consisting of positive retaining profiles provided on the narrow sides of the panels, which extend over the length of the narrow sides and are provided with joint projections or complementary joint recesses.
2. Background of the Prior Art
German utility model G 79 28 703 U1 describes a generic method for laying and interlocking floor panels with positive retaining profiles. These retaining profiles can be connected to each other by means of a rotary connecting movement. However, the disadvantage is that, in order to lay a second row of panels that is to be attached to a laid first row of panels, the second row first has to be completely assembled. The technical teaching to be taken from utility model G 79 28 703 U1 is that a first row of panels initially has to be laid ready horizontally and that a start is then made with a second panel in a second row, which has to be held at an angle and slid into a groove formed in the first panel row. The second panel has to be held at this angle, so that a third panel can be connected to the second panel. The same applies to the subsequent panels that have to be connected to each other in the second row. Only once all the panels of the second panel row have been pre-assembled in an inclined position can the entire second panel row be swung into horizontal position, this causing it to interlock with the first panel row. The unfavorable aspect of the laying method required for this panel design is the fact that several persons are required in order to hold all the panels of a second panel row in an inclined position for pre-assembly and then to jointly lower the second panel row into the laying plane.
Another method for laying and interlocking panels is known from EP 0 855 482 A2. In this case, panels to be laid in the second row are again connected to the panels of a first row in an inclined position. Adjacent panels of the second row are initially interlocked with the panels of the first row, leaving a small lateral distance between them. In this condition, the panels of the second row can be displaced along the first row. Retaining profiles provided on the short narrow sides of the panels are pressed into each other by sliding two panels of the second row against each other. Disadvantageously, the retaining profiles are greatly expanded and elongated during this process. Even during assembly, the retaining profiles already suffer damage that impairs the durability of the retaining profiles. The retaining profiles designed and laid according to the teaching of EP 0 855 482 A2 are not suitable for repeated laying. For example, retaining profiles molded from HDF or MDF material become soft as a result of the high degree of deformation to which the retaining profiles are subjected by the laying method according to EP 0 855 482 A2. Internal cracks and shifts in the fiber structure of the HDF or MDF material are responsible for this.
The object of the invention is thus to simplify the method for laying and interlocking panels and to improve the durability of the fastening system.
SUMMARY OF THE INVENTION
According to the invention, the object is solved by a method for laying and interlocking rectangular, plate-shaped panels, particularly floor panels, the opposite long narrow sides and opposite short narrow sides of which display retaining profiles extending over the length of the narrow sides, of which the opposite retaining profiles are designed to be essentially complementary to each other, where a first row of panels is initially connected on the short narrow sides, either in that the complementary retaining profiles of a laid panel and a new panel are slid into each other in the longitudinal direction of the short narrow sides, or in that the retaining profile of a new panel is initially inserted in an inclined position relative to the laid panel having the complementary retaining profile of the laid panel and subsequently interlocked, both in the direction perpendicular to the connected narrow ends and in the direction perpendicular to the plane of the laid panels, by pivoting into the plane of the laid panel, the next step being to lay a new panel in the second row, in that the retaining profile of its long narrow side is initially inserted into the retaining profile of the long narrow side of a panel of the first row by positioning at an angle relative to it and subsequently pivoting into the plane of the laid panels, and where a new panel, the short narrow side of which must be interlocked with the short narrow side of the panel laid in the second row and the long narrow side of which must be connected to the long narrow side of a panel laid in the first row, is first interlocked with the panel of the second row at its short narrow end, the new panel then being pivoted upwards out of the plane of the laid panels along the long narrow side of a panel laid in the first row, where the panel of the second row that was previously interlocked with the new panel on the short narrow side is also pivoted upwards, at least at this end, together with the new panel, into an inclined position in which the long retaining profile of the new panel can be inserted into the complementary retaining profile of the panel laid in the first row and, after insertion, the inclined new panel and the panel interlocked with the new panel on a short narrow side in the second row are pivoted into the plane of the laid panels.
According to the new method, panels to be laid in the second row can be fitted by a single person. A new panel can be interlocked both with panels of a first row and with a previously laid panel of the second row. This does not require interlocking of the short narrow sides of two panels lying in one plane in a manner that expands and deforms the retaining profiles.
The last panel laid in the second row can be gripped by its free, short narrow end and can be pivoted upwards into an inclined position about the interlocked, long narrow side as the pivoting axis. The panel is slightly twisted about its longitudinal axis in this process. The result of this is that the free, short narrow end of the panel is in an inclined position and the inclination decreases towards the interlocked, short narrow end of the panel. Depending on the stiffness of the panels, this can result in more or less strong torsion and thus in a greater or lesser decrease in the inclination. In the event of relatively stiff panels, the inclination can continue through several of the previous panels in the second row.
When laying, it is, of course, not necessary for the first row to be laid completely before making a start on laying the second row. During laying, attention must merely be paid to ensuring that the number of elements in the first row is greater than that in the second row, and so on.
The method can be realized particularly well when using thin, easily twisted panels. The inclination of a thin panel located in the second row decreases over a very short distance when subjected to strong torsion. The non-twisted remainder of a panel, or of a panel row, located in the laying plane, is securely interlocked. Only on the short, inclined part of the last panel of the second row can the retaining profiles of the long narrow sides become disengaged during the laying work. However, they can easily be re-inserted together with the new panel attached at the short narrow side.
A particularly flexible and durable design is one consisting of rectangular, plate-shaped panels that display complementary retaining profiles extending over the length of the narrow sides on narrow sides parallel to each other, where one retaining profile is provided in the form of a joint projection with a convex curvature and the complementary retaining profile in the form of a joint recess with a concave curvature, where each joint projection of a new panel is inserted into the joint recess of a laid panel, expanding it only slightly, and the new panel is finally interlocked by pivoting into the plane of the laid panel. The deformation of the retaining profiles required for laying and interlocking is considerably smaller than with retaining profiles that have to be pressed together perpendicular to their narrow sides in the laying plane. Advantageously, the joint projection does not protrude from the narrow side by more than the thickness of the panel. In this way, another advantage lies in the fact that the retaining profile can be milled on the narrow side of a panel with very little waste.
When laid, the retaining profiles of the long narrow sides of two panels, which can also be referred to as form-fitting profiles, form a common joint, where the upper side of the joint projection facing away from the substrate preferably displays a bevel extending to the free end of the joint projection, and where the bevel increasingly reduces the thickness of the joint projection towards the free end and the bevel creates freedom of movement for the common joint.
The design permits articulated movement of two connected panels. In particular, two connected panels can be bent upwards at the point of connection. If, for example, one panel lies on a substrate with an elevation, with the result that one narrow side of the panel is pressed onto the substrate when loaded, and the opposite narrow side rises, a second panel fastened to the rising narrow side is also moved upwards. However, the bending forces acting in this context do not damage the narrow cross-sections of the form-fitting profiles. An articulated movement takes place instead.
A floor laid using the proposed fastening system displays an elasticity adapted to irregularly rough or undulating substrates. The fastening system is thus particularly suitable for panels for renovating uneven floors in old buildings. Of course, it is also more suitable than the known fastening system when laying panels on a soft intermediate layer.
The design caters to the principle of “adapted deformability”. This principle is based on the knowledge that very stiff, and thus supposedly stable, points of connection cause high notch stresses and can easily fail as a result. In order to avoid this, components are to be designed in such a way that they display a degree of elasticity that is adapted to the application, or “adapted deformability”, and that notch stresses are reduced in this way.
Moreover, the form-fitting profiles are designed in such a way that a load applied to the upper side of the floor panels in laid condition is transmitted from the upper side wall of the joint recess of a first panel to the joint projection of the second panel and from the joint projection of the second panel into the lower-side wall of the first panel. When laid, the walls of the joint recess of the first panel are in contact with the upper and lower side of the joint projection of the second panel. However, the upper wall of the joint recess is only in contact with the joint projection of the second panel in a short area on the free end of the upper wall of the joint recess. In this way, the design permits articulated movement between the panel with the joint recess and the panel with the joint projection, with only slight elastic deformation of the walls of the joint recess. In this way, the stiffness of the connection is optimally adapted to an irregular base, which inevitably leads to a bending movement between panels connected to each other.
Another advantage is seen as lying in the fact that the laying and interlocking method according to the invention is more suitable for repeated laying than the known methods, because the panels display no damage to the form-fitting profiles after repeated laying and after long-term use on an uneven substrate. The form-fitting profiles are dimensionally stable and durable. They can be used for a substantially longer period and re-laid repeatedly during their life cycle.
Advantageously, the convex curvature of the joint projection and the concave curvature of the joint recess each essentially form a segment of a circle where, in laid condition, the center of the circle of the segments of the circle is located on the upper side of the joint projection or below the upper side of the joint projection. In the latter case, the center of the circle is located within the cross-section of the joint projection.
This simple design results in a joint where the convex curvature of the joint projection is designed similarly to the ball, and the concave curvature of the joint recess similarly to the socket, of a ball-and-socket joint, where, of course, in contrast to a ball-and-socket joint, only planar rotary movement is possible and not spherical rotary movement.
In a favorable configuration, the point of the convex curvature of the joint projection of a panel that protrudes farthest is positioned in such a way that it is located roughly below the top edge of the panel. This results in a relatively large cross-section of the joint projection in relation to the overall thickness of the panel. Moreover, the concave curvature of the joint recess offers a sufficiently large under-cut for the convex curvature of the joint projection, so that tensile forces acting in the laying plane can hardly move the panels apart.
The articulation properties of two panels connected to each other can be further improved if the inside of the wall of the joint recess of a panel that faces the substrate displays a bevel extending up to the free end of the wall and the wall thickness of this wall becomes increasingly thin towards the free end. In this context, when two panels are laid, the bevel creates space for movement of the common joint. This improvement further reduces the amount of elastic deformation of the walls of the joint recess when bending the laid panels upwards.
It is also expedient if the joint recess of a panel for connecting to the joint projection of a second panel can be expanded by resilient deformation of its lower wall and the resilient deformation of the lower wall occurring during connection is eliminated again when connection of the two panels is complete. As a result, the form-fitting profiles are only elastically deformed for the connection operation and during joint movement, not being subjected to any elastic stress when not loaded.
The ability also to connect the short narrow ends of two panels in articulated fashion benefits the resilience of a floor covering.
The form-fitting profiles preferably form an integral part of the narrow sides of the panels. The panels can be manufactured very easily and with little waste.
The laying method is particularly suitable if the panels consist essentially of an MDF (medium-density fiberboard), HDF (high-density fiberboard), or particleboard material. These materials are easy to process and can be given a sufficient surface quality by means of cutting processes, for example. In addition, these materials display good dimensional stability of the milled profiles.
The various features of novelty that characterize the invention will be pointed out with particularity in the claims of this application.
BRIEF DESCRIPTION OF THE DRAWINGS
An example of the invention is illustrated in a drawing and described in detail below on the basis of FIGS. 1 to 9 . The figures show the following:
FIG. 1 —illustrates an exploded side view of two panels prior to connection,
FIG. 2 —illustrates a side view of the panels in FIG. 1 in assembled condition,
FIG. 3 —illustrates an exploded side view of two panels being connected where the joint projection of one panel is inserted in the joint recess of a second panel in the direction of the arrow and the first panel is subsequently locked in place by a rotary movement,
FIG. 4 —illustrates an exploded side view where the joint projection of a first panel is slid into the joint recess of a second panel parallel to the laying plane,
FIG. 5 —illustrates a side view of the assembled panels of FIG. 2 , where the common joint is moved upwards out of the laying plane and the two panels form a bend,
FIG. 6 —illustrates a side view of the assembled panels of FIG. 2 , where the common joint is moved downwards out of the laying plane and the two panels form a bend,
FIG. 7 —illustrates a side view of two assembled panels, with a filler material between the form-fitting profiles of the narrow sides,
FIG. 8 —illustrates a perspective view of the method for laying and interlocking rectangular panels, and
FIG. 9 —illustrates a perspective view of an alternative method for laying and interlocking rectangular panels.
DETAILED DESCRIPTION OF THE INVENTION
According to the drawing, fastening system 1 , required for the method for laying and interlocking rectangular panels, is explained based on oblong, rectangular panels 2 and 3 , a section of which is illustrated in FIG. 1 . Fastening system 1 displays retaining profiles, which are located on the narrow sides of the panels and designed as complementary form-fitting profiles 4 and 5 . The opposite form-fitting profiles of a panel are of complementary design in each case. In this way, a further panel 3 can be attached to every previously laid panel 2 .
Form-fitting profiles 4 and 5 are based on the prior art according to German utility model G 79 28 703 U1, particularly on the form-fitting profiles of the practical example. The form-fitting profiles according to the invention are developed in such a way that they permit the articulated and resilient connection of panels.
One of the form-fitting profiles 4 of the present invention is provided with a joint projection 6 protruding from one narrow side. For the purpose of articulated connection, the lower side of joint projection 6 , which faces the base in laid condition, displays a cross-section with a convex curvature 7 . Convex curvature 7 is mounted in rotating fashion in complementary form-fitting profile 5 . In the practical example shown, convex curvature 7 is designed as a segment of a circle. Part 8 of the narrow side of panel 3 , which is located below joint projection 6 and faces the base in laid condition, stands farther back from the free end of joint projection 6 than part 9 of the narrow side, which is located above joint projection 6 . In the practical example shown, part 8 of the narrow side, located below joint projection 6 , recedes roughly twice as far from the free end of joint projection 6 and part 9 of the narrow side, located above joint projection 6 . The reason for this is that the segment of a circle of convex curvature 7 is of relatively broad design. As a result, the point of convex curvature 7 of joint projection 6 that projects farthest is positioned in such a way that it is located roughly below top edge 10 of panel 3 .
Part 9 of the narrow side, located above joint projection 6 , protrudes from the narrow side on the top side of panel 3 , forming abutting joint surface 9 a . Part 9 of the narrow side recedes between this abutting joint surface 9 a and joint projection 6 . This ensures that part 9 of the narrow side always forms a closed, topside joint with the complementary narrow side of the second panel 2 .
The upper side of joint projection 6 , opposite convex curvature 7 of joint projection 6 , displays a short, straight section 11 that is likewise positioned parallel to substrate U in laid condition. From this short section 11 to the free end, the upper side of joint projection 6 displays a bevel 12 that extends up to the free end of joint projection 6 .
Form-fitting profile 5 of a narrow side, which is complementary to form-fitting profile 4 described, displays a joint recess 20 . This is essentially bordered by a lower wall 21 that faces substrate U in laid condition, and an upper wall 22 . On the inside of joint recess 20 , lower wall 21 is provided with a concave curvature 23 . Concave curvature 23 is likewise designed in the form of a segment of a circle. In order for there to be sufficient space for the relatively broad concave curvature 23 on lower wall 21 of joint recess 20 , lower wall 21 projects farther from the narrow side of panel 2 than upper wall 22 . Concave curvature 23 forms an undercut at the free end of lower wall 21 . In finish-laid condition of two panels 2 and 3 , this undercut is engaged by joint projection 6 of associated form-fitting profile 4 of adjacent panel 3 . The degree of engagement, meaning the difference between the thickest point of the free end of the lower wall and the thickness of the lower wall at the lowest point of concave curvature 23 , is such that a good compromise is obtained between flexible resilience of two panels 2 and 3 and good retention to prevent form-fitting profiles 4 and 5 being pulled apart in the laying plane.
In comparison, the fastening system of the prior art utility model G 79 28 703 U1 displays a considerably greater degree of undercut. This results in extraordinarily stiff points of connection, which cause high notch stresses when subjected to stress on an uneven substrate.
According to the practical example, the inner side of upper wall 22 of joint recess 20 of panel 2 is positioned parallel to substrate U in laid condition.
On lower wall 21 of joint recess 20 of panel 2 , which faces substrate U, the inner side of wall 21 has a bevel 24 that extends up the free end of lower wall 21 . As a result, the wall thickness of this wall becomes increasingly thin towards the free end. According to the practical example, bevel 24 follows on from the end of concave curvature 23 .
Joint projection 6 of panel 3 and joint recess 20 of panel 2 form a common joint G, as illustrated in FIG. 2 . When panels 2 and 3 are laid, the previously described bevel 12 , on the upper side of joint projection 6 of panel 3 , and bevel 24 of lower wall 21 of joint recess 20 of panel 2 create spaces for movement 13 and 25 , which allow joint G to rotate over a small angular range.
In laid condition, short straight section 11 of the upper side of joint projection 6 of panel 3 is in contact with the inner side of upper wall 22 of joint recess 20 of panel 2 . Moreover, convex curvature 7 of joint projection 6 lies against concave curvature 23 of lower wall 21 of joint recess 20 of panel 2 .
Lateral abutting joint surfaces 9 a and 26 of two connected panels 2 and 3 , which face the upper side, are always definitely in contact. In practice, simultaneous exact positioning of convex curvature 7 of joint projection 6 of panel 3 against concave curvature 23 of joint recess 20 of panel 2 is impossible. Manufacturing tolerances would lead to a situation where either abutting joint surfaces 9 a and 26 are positioned exactly against each other or joint projection 6 /recess 20 are positioned exactly against each other. In practice, the form fitting profiles are thus designed in such a way that abutting joint surfaces 9 a and 26 are always exactly positioned against each other and joint projection 6 /recess 20 cannot be moved far enough in each other to achieve an exact fit. However, as the manufacturing tolerances are in the region of hundredths of a millimeter, joint projection 6 /recess 20 also fit almost exactly.
Panels 2 and 3 , with complementary form-fitting profiles 4 and 5 described, can be fastened to each other in a variety of ways. According to FIG. 3 , one panel 2 with a joint recess 20 has already been laid, while a second panel 3 , with a complementary joint projection 6 , is being inserted into joint recess 20 of first panel 2 at an angle in the direction of the arrow P. After this, second panel 3 is rotated about the common center of circle K of the segments of a circle of convex curvature 7 of joint projection 6 and concave curvature 23 of joint recess 20 until second panel 3 lies on substrate U.
Another way of joining the previously described panels 2 and 3 is illustrated in FIG. 4 , according to which first panel 2 with joint recess 20 has been laid and a second panel 3 with joint projection 6 is slid in the laying plane and perpendicular to form-fitting profiles 4 and 5 in the direction of the arrow P until walls 21 and 22 of joint recess 20 expand elastically to a small extent and convex curvature 7 of joint projection 6 has overcome the undercut at the front end of concave curvature 23 of the lower wall and the final laying position is reached.
The latter way of joining is preferably used for the short narrow sides of a panel if these are provided with the same complementary form-fitting profiles 4 and 5 as the long narrow sides of the panels.
FIG. 5 illustrates fastening system 1 in use. Panels 2 and 3 are laid on an uneven substrate U. A load has been applied to the upper side of first panel 2 with form-fitting profile 5 . The narrow side of panel 2 with form-fitting profile 5 has been lifted as a result. Form-fitting profile 4 of panel 3 , which is connected to form-fitting profile 5 , has also been lifted. Joint G results a bend between the two panels 2 and 3 . The spaces for movement 13 and 25 create room for the rotary movement of the joint. Joint G, formed by the two panels 2 and 3 , has been moved slightly upwards out of the laying plane. Space for movement 13 has been utilized to the full for rotation, meaning that the area of bevel 12 on the upper side of joint projection 6 of panel 3 is in contact with the inner side of wall 22 of panel 2 . The point of connection is inherently flexible and does not impose any unnecessary, material-fatiguing bending loads on the involved form-fitting profiles 4 and 5 .
The damage soon occurring in form-fitting profiles according to the prior art, owing to the breaking of the joint projection or the walls of the form-fitting profiles, is avoided in this way.
Another advantage results in the event of movement of the joint in accordance with FIG. 5 . This can be seen in the fact that, upon relief of the load, the two panels drop back into the laying plane under their own weight. Slight elastic deformation of the walls of the joint recess is also present in this case. This elastic deformation supports the panels in dropping back into the laying plane. Only very slight elastic deformation occurs because the center of motion of the joint, which is defined by curvatures 7 and 23 with the form of a segment of a circle, is located within the cross-section of joint projection 6 of panel 3 .
FIG. 6 illustrates movement of the joint of two laid panels 2 and 3 in the opposite sense of rotation. Panels 2 and 3 , laid on uneven substrate U, are bent downwards. The design is such that, in the event of downward bending of the point of connection out of the laying plane towards substrate U, far more pronounced elastic deformation of lower wall 21 of joint recess 20 occurs than during upward bending from the laying plane. This measure is necessary because downward-bent panels 2 and 3 cannot return to the laying plane as a result of their own weight when the load is relieved. However, the greater elastic deformation of lower wall 21 of joint recess 20 generates an elastic force that immediately moves panels 2 and 3 back into the laying plane in the manner of a spring when the load is relieved.
In the present form, the previously described form-fitting profiles 4 and 5 are integrally molded on the narrow sides of panels 2 and 3 . This is preferably achieved by means of a so-called formatting operation, where a number of milling tools connected in series mills the shape of form-fitting profiles 4 and 5 into the narrow sides of panels 2 and 3 . Panels 2 and 3 of the practical example described essentially consist of MDF board with a thickness of 8 mm. The MDF board has a wear-resistant and decorative coating on the upper side. A so-called counteracting layer is applied to the lower side in order to compensate for the internal stresses caused by the coating on the upper side.
Finally, FIG. 7 shows two panels 2 and 3 in laid condition, where fastening system 1 is used with a filler 30 that remains flexible after curing. Filler 30 is provided between all adjacent parts of the positively connected narrow sides. In particular, the topside joint 31 is sealed with the filler to prevent the ingress of any moisture or dirt. In addition, the elasticity of filler 30 , which is itself deformed when two panels 2 and 3 are bent, brings about the return of panels 2 and 3 to the laying plane.
FIG. 8 shows a perspective representation of the laying of a floor, where the method for laying and interlocking panels according to the invention is used. For the sake of the simplicity of the drawing, the details of the retaining profiles have been omitted. However, these correspond to the form-fitting profiles in FIGS. 1 to 7 and display profiled joint projections and complementary joint recesses that extend over the entire length of the narrow sides.
A first row R 1 , comprising rectangular, plate-like panels 40 , 41 , 42 and 43 , can be seen. Panels 40 , 41 , 42 and 43 of first row R 1 are preferably laid in such a way that joint recesses are always located on the free sides of a laid panel and new panels can be attached by their joint projections to the joint recesses of the laid panels.
Panels 40 , 41 , 42 and 43 of fist row R 1 have been interlocked at their short sides. This can be done either in the laying plane by sliding the panels laterally into each other in the longitudinal direction of the retaining profiles of the short narrow sides or, alternatively, by joining the retaining profiles while positioning a new panel at an angle relative to a laid panel and subsequently pivoting the new panel into the laying plane. The laying plane is indicated by broken line V in FIGS. 8 and 9 . The retaining profiles have been interlocked without any major deformation in both cases. The panels are interlocked in the direction perpendicular to the laying plane. Moreover, they are also interlocked in the direction perpendicular to the plane of the narrow sides.
Panels 44 , 45 and 46 are located in a second row R 2 . First, the long side of panel 44 was interlocked by inserting its joint projection by positioning it at an angle relative to the panels of first row R 1 and subsequently pivoting panel 44 into the laying plane.
In order to lay a new panel in the second row, several alternative procedural steps can be performed, two alternatives of which are described on the basis of FIGS. 8 and 9 . A further alternative is explained without an illustration.
When laying a new panel 46 in the second row, one of its long sides has to be interlocked with first row R 1 and one of its short sides with laid panel 45 . A short side of new panel 46 is always first interlocked with laid panel 45 .
According to FIG. 8 , free end 45 a is pivoted upwards out of the laying plane through a pivoting angle α about interlocked long narrow side 45 b . Panel 45 is twisted in such a way during the process that the dimension of pivoting angle α decreases from free end 45 a towards interlocked end 45 c . According to FIG. 8 , interlocked end 45 c remains in place in the laying plane. In this position, new panel 46 is set at an angle relative to panel 45 on free end 45 a of the latter. Panel 46 can initially not be set against the whole length of the short side, because panel 45 is already interlocked with panels 41 and 42 of the first row. Panel 46 is now pivoted in the direction of arrow A until it is likewise positioned at pivoting angle α relative to the laying plane, as indicated by dotted pivoting position 46 ′. In pivoting position 46 ′, panel 46 is slid in the direction of arrow B and the joint projection of panel 46 is inserted into the joint recess of panels 42 and 43 of first row R 1 . In this context, the short narrow side of panel 46 is simultaneously slid completely onto short narrow side 45 a of panel 45 . Finally, panels 45 and 46 are jointly pivoted into the laying plane in the direction of arrow C and interlocked with the panels of first row R 1 .
Damage to the retaining profiles due to a high degree of deformation during laying and interlocking is avoided.
The alternative laying method according to FIG. 9 likewise provides for free end 45 a to be pivoted upwards out of the laying plane by a pivoting angle α about interlocked long narrow side 45 b , where panel 45 is twisted and its free end 45 a is inclined through a pivoting angle α relative to the laying plane. Interlocked end 45 c again remains in place in the laying plane. In contrast to FIG. 8 , panel 46 is now likewise positioned at the pivoting angle α relative to the laying plane and its short side 46 a is slid in the longitudinal direction onto the retaining profile of short side 45 a of panel 45 . In this inclined position, the joint projection of long side 46 b of panel 46 is immediately inserted into the joint recess of panels 42 and 43 of first row R 1 . Finally, panels 45 and 46 are jointly pivoted into the laying plane and interlocked with the panels of first row R 1 .
The alternatives not shown for laying and interlocking panels consist in first interlocking the short narrow ends of panels 45 and 46 in the laying plane. The alternatives described here can be followed by examining FIGS. 8 and 9 , which is why reference numbers are also given for the alternatives not illustrated.
According to one of the alternatives, the retaining profiles of short narrow sides 45 a and 46 a of panels 45 and 46 are slid into each other in the longitudinal direction while both panels 45 and 46 remain in place in the laying plane. According to another alternative, panel 45 lies in the laying plane and panel 46 is set at an angle against short narrow side 45 a of panel 45 and then pivoted into the laying plane.
According to the above alternative procedural steps for interlocking panels 45 in the laying plane, the long side of panel 46 is not yet interlocked with panels 42 and 43 of first row R 1 . To this end, panel 46 and end 45 a of panel 45 must be lifted into the previously described inclined position at pivoting angle α. The joint projection of long side 46 b of panel 46 is then inserted into the joint recess of panels 42 and 43 of first row R 1 , and panels 45 and 46 are finally jointly interlocked with panels 42 and 43 of first row R 1 by being pivoted into laying plane V.
Although certain presently preferred embodiments of the disclosed invention have been specifically described herein, it will be apparent to those skilled in the art to which the invention pertains that variations and modifications of the various embodiments shown and described herein may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the invention be limited only to the extent required by the appended claims and the applicable rules of law. | The method for laying and interlocking the panels uses panels with complementary, formfitting retaining profiles extending over the length of the sides. The complementary edges of the panels allow two adjacent panels to be positively joined such that displacement of the panels away from one another is prevented, while enabling articulation of the panels with respect to one another at the joint location. The method of installation provides for installing a new panel to a first row and a panel in a second row by first joining the new panel to the panel of the second row at its short side, followed by pivoting the new panel upwards out of the plane of the laid panels along its long side, along with at least the adjacent end of the first panel in the second row, into an inclined position, and sliding the new panel into the retaining profile of the panels in the first row. The new panel and the raised end of the panel in the second row are then pivoted down into the plane of the laid panels. Laying of panels continues according to this process until the complete floor assembly has been laid. | 4 |
RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 11/522,814, filed on Sep. 14, 2006 entitled “Tube Fitting with Separable Tube Gripping Device” which is a continuation of U.S. patent application Ser. No. 10/467,444, filed on Aug. 5, 2003, now U.S. Pat. No. 7,108,288 entitled “Tube Fitting with Separable Tube Gripping Ring” which claims priority to International Patent Application Serial No. PCT/US02/03431, filed on Feb. 6, 2002 entitled “Tube Fitting with Separable Tube Gripping Ring” which claims the benefit of U.S. Provisional patent application Ser. No. 60/266,735 filed on Feb. 6, 2001 entitled “Tube Fitting with Integral Nut and Ferrule”, and Ser. No. 60/329,943 filed on Oct. 17, 2002 entitled “Tube Fitting”, the entire disclosures of which are fully incorporated by reference.
TECHNICAL FIELD OF THE INVENTION
The subject invention is generally directed to the art of tube fittings.
BACKGROUND OF THE INVENTION
Tube fittings are used to join or connect a tube end to another member, whether that other member be another tube end such as through T-fittings and elbow fittings, for example, or a device that needs to be in fluid communication with the tube end, such as for example, a valve. As used herein the terms “tube” and “tubing” are intended to include but not be limited to pipe as well. Any tube fitting must accomplish two important functions within the pressure, temperature and vibration criteria that the tube fitting is designed to meet. First, the tube fitting must grip the tube end so as to prevent loss of seal or tube blow out. Secondly, the tube fitting must maintain a primary seal against leakage. The requirement that a tube fitting accomplish these two functions has been the driving factor in tube fitting design for decades. A multitude of factors influence the design of a tube fitting to meet a desired grip and seal performance criteria, but basic to any tube fitting design will be: 1) the characteristics of the tubing that the fitting must work with, including the material, outside diameter and wall thickness; and 2) the tube grip and seal performance level required of the tube fitting for its intended applications. The goal is to design a tube fitting that reliably achieves the desired tube grip and seal functions within whatever cost constraints are imposed on the product by competing designs in the marketplace.
A flareless tube fitting generally refers to a type of tube fitting in which the tube end remains substantially tubular, in contrast to a flared tube fitting in which the tube end is outwardly flared over a fitting component. Flared tube ends are commonly encountered in use with plastic tubing and plastic tube fittings. The present invention is not primarily directed to plastic tubing or tube fittings because such fittings have significantly different challenges and material properties that affect the ability of the fitting to both grip the tube and provide an adequate seal. However, some of the aspects of the invention may apply to non-metal tube fittings, particularly the separable tube gripping element aspect.
Tube fittings that are intended for use with stainless steel and other metal tubing, for example, are particularly challenging to design in order to achieve the desired tube grip and seal functions. This arises from the nature of stainless steel which, in terms of typical commercially available tubing material, is a very hard material, usually on the order of up to 200 Vickers. Stainless steel and other metal tubing is also used for high pressure applications in which the tubing wall thickness is substantial (referred to in the art as “heavy walled” tubing). Heavy wall tubing is difficult to grip because it is not only hard but it is also not particularly ductile. Low ductility makes it more difficult to deform the tubing plastically so as to achieve a desired tube grip.
Tube fittings typically include an assembly of: 1) a tube gripping device, often in the form of a ferrule or ferrules, or a gripping ring-like structure, and 2) a pull-up mechanism for causing the tube gripping device to be installed on a tube end so as to grip the tube end and provide a seal against leakage. The term “pull-up” simply refers to the operation of tightening the tube fitting assembly so as to complete the assembly of the fitting onto the tube end with the desired tube grip and seal.
Usually a tube fitting is first assembled in a “finger tight” condition and then a wrench or other suitable tool is used to tighten or “pull up” the fitting to its final initial and complete assembled condition. The pull up mechanism most commonly used is a threaded connection of a female threaded nut component and a male threaded body component, with the tube gripping device being acted upon by these two components as they are threaded and tightened together. The body includes a tube end receiving bore with an angled camming surface at the outer portion of that bore. The most commonly used camming surfaces are frusto-conical such that the term “camming angle” refers to the cone angle of the camming surface relative to the tube end longitudinal axis or outer surface. The tube end is axially inserted into the body bore and extends past the frusto-conical camming surface. The gripping device is slipped onto the tube end and the nut is partially threaded onto the body to the finger tight position such that the tube gripping device captured axially between the camming surface and the nut. The nut typically includes an inward shoulder that drives the tube gripping device into engagement with the angled camming surface on the body as the nut and body components are threadably tightened together. The angled camming surface imparts a radial compression to the tube gripping device, forcing the tube gripping device into a gripping engagement with the tube end. The tube gripping device typically is to form a seal against the outer surface of the tubing and also against the angled camming surface.
The most commonly used tube gripping devices in stainless steel tube fittings today (the most commonly used are ferrule-type tube fittings) achieve tube grip by causing a front or nose portion of the tube gripping device to bite into the tube end outer surface. As used herein, the term “bite” refers to the plastic deformation of the tube gripping device into the outer surface of the tube end so as to plastically deform and indent the tubing with an almost cutting-like action to create a generally radial shoulder or wall at the front end of the tube gripping device. This “bite” thus serves as a strong structural feature to prevent tube blow out at high pressure, particularly for larger diameter tubing such as ½″ and higher.
Over the years there have been numerous tube fitting designs that do not rely on a “bite” type action, but rather merely radially compress the tube gripping device against the tubing outer surface, some with the effect of indenting into the tubing without creating a bite. These designs are not suitable for high pressure stainless steel tube fittings. The most common commercially available stainless steel tube fittings especially for high pressure applications have historically been of two radically distinct designs of the tube gripping device-single ferrule tube fittings and two ferrule tube fittings.
A single ferrule tube fitting, as the name implies, uses a single ferrule to accomplish both the tube grip and seal functions. However, it is becoming increasingly recognized that these two functions are at odds with each other when designing a tube fitting that can meet a desired tube grip and seal performance criteria. This is because the design criteria needed to assure that the tube fitting achieves an adequate tube grip usually works against the ability of the single ferrule to also provide an effective seal. Consequently, although prior art single ferrule fittings can achieve adequate tube grip in some cases, this tube grip performance comes at the expense of having a less effective seal. One result of this situation is that some single ferrule tube fittings have been designed with additional components and techniques to achieve an adequate seal. Less than optimum seal performance is particularly noted in single ferrule fittings that attempt to seal against gas, and especially high pressure gas. Single ferrule tube fittings thus are usually more suited to lower pressure liquid applications such as hydraulics, however, even in such lower pressure applications single ferrule seal performance remains less than desired.
For single ferrule tube fittings, the biting action is usually associated with the single ferrule being designed to bow in a radially outward direction from the tube wall in the central region or mid-portion of the single ferrule body between the front and back ends thereof. The front end of the ferrule is driven against the angled camming surface of the body by the nut pushing against the back end of the ferrule. The bowing action helps direct the front end of the single ferrule into the tube end. The bowing action is also used to cause the back end of the ferrule to likewise engage and grip the tube end. This is accomplished usually by provided an angled drive surface on the nut shoulder that engages the back end of the single ferrule so as to radially compress the back end of the ferrule into a gripping action on the tube end. In some single ferrule designs, the back end of the ferrule apparently is intended to bite into the tube end. This back end tube grip is sometimes used with the single ferrule in order to attempt to improve the tube fitting's performance under vibration because the back end grip attempts to isolate down-tube vibration from affecting the front end tube bite.
The use of a back end tube grip actually works against the effort to grip the tube end at the front end of the single ferrule. Ideally, the single ferrule should be completely in three dimensional compression between the nut and the camming surface of the body. Providing a back end grip actually places a counter acting tension to the single ferrule that works against the front end compression being used to provide the tube grip. Additionally, the outward bowing action tends to work against the effort to grip the tube at the front end of the single ferrule because, in order to enable the outward bowing action, the single ferrule requires a lessened mass that is adjacent the tube gripping “bite”. The outward bowing action radially displaces ferrule mass central to the ferrule body away from the tube end. Consequently, an outwardly bowed single ferrule fitting could be more susceptible to ferrule collapse, loss of seal and possibly tube blow out at higher pressures.
In order to achieve an adequate tube grip on stainless steel tubing, single ferrule stainless steel tube fittings have historically used a rather shallow camming angle of between ten and twenty degrees. This range of angles is referred to herein as “shallow” only as a term of convenience in that the angle is rather small. The shallow camming angle has been used in single ferrule fittings to obtain a mechanical advantage because the shallow angle provides an axially elongated camming surface against which to slide and radially compress the single ferrule front end to bite into the tube end outer surface. Hard stainless steel tubing material necessitated this elongated sliding camming action in order to be able to get the single ferrule to create an adequate bite for tube grip. Over the years, the single ferrule has been through hardened or case hardened so as to be significantly harder than the stainless steel tubing, however, the shallow camming angle is still used today in such single ferrule fittings to obtain a mechanical advantage from the ferrule sliding along the camming surface to produce the “bite” so as to assure an adequate tube grip. An example of a commercially available single ferrule tube fitting that uses a case hardened ferrule and a shallow camming angle of about twenty degrees is the CPI fitting line available from Parker-Hannifin Corporation. Another example is the EO fitting line available from Ermeto GmbH that uses a through hardened single ferrule and a twelve degree camming angle.
In some single ferrule designs, a non-conical camming surface has been tried whereby an attempt is made to simply press the ferrule against the outer surface of the tube end, thereby not creating a bite. The result in such cases however is a low grip or low pressure only fitting that are not well suited to stainless steel fittings.
The shallow camming angle and elongated camming surface and axial movement needed to achieve an adequate tube grip with a single ferrule fitting, however, compromises the ability of the single ferrule to achieve the seal function, especially in extreme environments and for sealing gas. This is because the front end of the single ferrule attempts to make the seal against the axially elongated camming surface. The radially outward bowing action causes a larger portion of the outer surface of the front end of the single ferrule to come into contact with the camming surface against which it is being driven. The result necessarily is a larger seal surface area between the outer surface of the single ferrule and the camming surface. This enlarged seal area causes an unwanted distribution of the sealing force between the single ferrule and the camming surface, and also creates a larger area for surface imperfections to allow leaks to occur. This is particularly a metal to metal seal issue (as contrasted to non-metal to non-metal seals: for example, in a plastic fitting it is usually desirable to provide an enlarged seal contact area because the more highly ductile plastic material can better form a seal between the two surfaces.)
Because historically the single ferrule fitting has used a shallow camming angle to achieve adequate tube grip, the less than optimum seal function is either tolerated as a recognized limitation on the application of the fitting, or additional features have been designed into the single ferrule fitting, most notably attempts to include one or more elastomeric seals with the single ferrule or with which the single ferrule cooperates to provide a better seal with stainless steel tubing. See, for example, U.S. Pat. Nos. 6,073,976 and 5,351,998. U.S. Pat. No. 6,073,976 illustrates a typical example of a single “ferrule” (called a “cutting ring” in the patent) fitting that attempts to solve the “seal” issue with added elastomeric seal. The U.S. Pat. No. 5,351,998 describes the benefits obtained by separating the tube grip and seal functions into two separate components.
A commercially available and highly successful two ferrule fitting used for tubing is commercially available from Swagelok Company, Solon, Ohio and is described in U.S. Pat. Nos. 6,131,963 and 3,103,373 both of which are owned in common by the assignee of the present invention, the entire disclosures of which are fully incorporated herein by reference. In this two ferrule fitting, the tube grip and seal functions also are separately achieved by the use of two ferrules. The forward or front ferrule provides an excellent seal even against gas, and the back or rear ferrule provides an excellent tube grip.
The front ferrule achieves an excellent seal by camming against a shallow camming surface angle such as twenty degrees. This is because the front ferrule does not need to slide excessively on the camming surface in order to achieve a tube grip function. Likewise, the front ferrule is not case hardened because the primary purpose of the front ferrule is to seal and is not to bite into the tube end. Thus the relatively “softer” front ferrule achieves an excellent seal, particularly against gas, even though the body conical camming surface presents a camming angle of about twenty degrees.
The back ferrule achieves the tube grip function in the above noted two ferrule tube fitting. The back ferrule is case hardened to be substantially harder than the tube end. The front end of the back ferrule cams against a frusto-conical camming surface formed in the back end of the front ferrule. The ostensible angle of this camming surface is forty-five degrees, but due to the sliding movement of the front ferrule, the effective camming angle is actually a shallow angle of about fifteen to twenty degrees. Although the effective camming angle for the back ferrule is shallow, the back ferrule is not required to provide a primary seal (although it can form secondary or backup seals). The back ferrule also does not exhibit the undesired bowing action but rather grips the tube end as a function of a radially inward hinging action. As used herein, the term “hinging” refers to a controlled deformation of the ferrule such that a central region or mid-portion of the ferrule body undergoes an inwardly radial compression, as distinctly contrasted to a bowing or radially outward displacement. Thus, the effective shallow camming angle not only does not compromise the fitting seal capability, it actually substantially enhances the overall performance of the tube fitting especially for stainless steel tubing.
By using separate ferrules for each to achieve primarily only one of the key tube fitting functions, the two ferrule tube fitting achieves tremendous tube grip and seal functions. This prior art two ferrule tube fitting thus has enjoyed tremendous commercial success especially in the art of stainless steel tubing in part due to its performance characteristics such as high pressure rating on the order of 15000 psi, wide temperature rating of cryogenic to 1200° F. and in many applications a significant number of remakes (a “remake” refers to the loosening and re-tightening of a fitting after an initial pull-up).
U.S. Pat. No. 3,248,136 illustrates use of a single locking ring as opposed to a ferrule, wherein the locking ring acts against a surface having an angle that appears to be greater than twenty degrees or more, but the ring does not appear to plastically deform into the tubing but rather remains elastic so that the ring is designed to retain its original shape after pull-up, both of which are features that are unsuitable for stainless steel tube fittings of the type considered herein. Japanese utility model publication 44-29659 illustrates a tightening ring that appears to be intended to have a bowing effect and grip the tube at the front and back ends. The fitting does not appear to be applicable to stainless steel tubing as the tube is covered with a resin cover.
Attempts have been made to design tube fittings with a tube gripping element that separates during pull-up to function as a single element tube gripping device. Known designs place the breakaway element on the male threaded component. Additionally, the known designs either force the tube gripping element against a shallow camming surface angle or do not attempt to create a tube gripping bite into the tube wall. Thus the prior art designs suffer from the same limitations as the prior art single ferrule tube fitting designs.
Many applications and uses of the above-described two ferrule SWAGELOK tube fitting do not require such high pressure, temperature and remake performance characteristics. The present invention is directed to a new fitting concept that can meet lower performance characteristics without compromising overall fitting integrity and performance.
SUMMARY OF THE INVENTION
In accordance with one aspect of the invention, a new tube fitting concept provides an indication of completed pull-up by engaging an internal surface of one fitting component with another fitting component. In one embodiment, a tube fitting has a first coupling member and a second coupling member joined with the first coupling member. A tube gripping device is disposed between the first coupling member and the second coupling member such that assembly of said first coupling member with said second coupling member to a pulled-up condition causes the tube gripping device to grip and seal the tube. The first coupling member engages an internal surface of the second coupling member to provide an indication of completed pull-up.
These and other aspects and advantages of the present invention will be apparent to those skilled in the art from the following description of the preferred embodiments in view of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangements of parts, preferred embodiments and a method of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof, and wherein:
FIG. 1 illustrates in half longitudinal cross-section an exemplary embodiment of a tube fitting in accordance with the invention in a finger tight position;
FIG. 2 illustrates the embodiment of FIG. 1 in a partially pulled up position;
FIG. 3 illustrates the embodiment of FIG. 1 in a completed initial pulled up position; and
FIG. 4 illustrates another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In accordance then with one aspect of the invention, a tube fitting is provided having a tube gripping device that initially is integral with one of the coupling elements and upon pull-up separates therefrom to function as a single ferrule fitting. In the preferred embodiment, the tube gripping device or ferrule is integrally formed with a female threaded nut and is attached thereto by a frangible thin web portion that breaks as the ferrule cams initially against a camming surface of the male threaded component. As a single ferrule after separation, the ferrule acts against the steep camming angle surface of a male threaded body. The steep camming surface angle is particularly advantageous when the hardness of the tube gripping device has a ratio of at least about 3.3 times greater and preferably at least 4 times greater to the hardness of the tubing material.
Although a number of aspects of the invention are described herein as being incorporated into the exemplary embodiments, such description should not be construed in a limiting sense. For any particular application the various aspects of the invention may be used as required in different combinations and sub-combinations thereof. Furthermore, although the present disclosure describes and/or illustrates a number of design choices and alternative embodiments, such descriptions are not intended to be and should not be construed as an exhaustive list of such choices and alternatives. Those skilled in the art will readily appreciate and understand additional alternatives and design choices that are within the spirit and scope of the invention as set forth in the appended claims.
Although the various embodiments are described herein with specific reference to the fitting components being made of stainless steel, and in particular 316 stainless steel, such description is intended to be exemplary in nature and should not be construed in a limiting sense. Those skilled in the art will readily appreciate that the invention may be realized using any number of different types of metal materials for the fitting components, as well as metal tubing materials, including but not limited to 316, 316L, 304, 304L, any austenitic or ferritic stainless steel, any duplex stainless steel, any nickel alloy such as HASTALLOY, INCONEL, or MONEL, any precipitation hardened stainless steel such as 17-4PH for example, brass, copper alloys, any carbon or low alloy steel such as 1018 steel for example, and any leaded, re-phosphorized or re-sulphurized steel such as 12L14 steel for example. An important aspect of the choice of materials is that the tube gripping device preferably should be case or through hardened to a ratio of at least about 3.3 and preferably 4 or more times harder than the hardest tubing material that the fitting will be used with. Therefore, the tube gripping device need not be made of the same material as the tubing itself. For example, as will be discussed hereinbelow, the tube gripping device may be selected from the stainless steel materials noted above, or other suitable materials that can be case hardened, such as magnesium, titanium and aluminum, to name some additional examples. Furthermore, the frangible feature of the tube gripping ring and female threaded nut may also be realized in non-metal tube fittings.
With reference to FIG. 1 , the present invention contemplates a tube fitting 50 in which there are only two discrete components prior to assembly, namely a female threaded nut 52 and a male threaded body 54 . The nut 52 is substantially different from the typical nut used in a prior art ferrule type tube fittings. The body 54 may be the similar in general design as a typical body used in prior fittings, however, as will be explained further herein, it is preferred but not necessary that the body 54 also be optimized for proper make-up with the new nut 52 . Additionally, the body 54 need not be a discretely separate component but may be attached to or otherwise integral to another part such as a valve body, manifold or other components for example.
Note that in the drawings the fittings are illustrated in longitudinal cross-section but only half of the section is illustrated, it being understood that the other half is identical and omitted for clarity and ease of illustration. In all of the illustrations herein, various gaps and dimensions are somewhat exaggerated for ease of illustration.
The body 54 is a generally cylindrical main body 56 that has an integral extension or end 56 a . The end extension 56 a may be a hex body, for example, or part of another component such as for example a valve body as noted hereinabove. The main body 56 may be machined from the same stock as the end extension 56 a or may be otherwise attached such as by welding or other suitable technique. The body 56 includes a first central longitudinal bore 58 that is appropriately sized to closely and slideably receive a tube end 13 . The first bore 58 is somewhat larger in diameter than a coaxial second bore 59 that extends through the end extension 56 a of the body 54 . Of course, if the fitting 50 is a closed end connection, the inner bore 59 would not be a through bore.
The tube end 13 preferably bottoms against a counterbore 60 . The body 56 is machined or otherwise formed with external male threads 62 that threadably mate with corresponding female threads 64 formed or machined in the nut 52 . It is contemplated that in order to avoid inadvertent mixing of old and new style body and nut parts with prior art fitting components, that the thread pitch on the nut and body of the present invention may be substantially different from the thread pitch values of prior art ferrule-type tube fitting nuts and bodies. This will avoid interchange problems and also allows for a course pitch that provides high axial stroke with reduced nut rotation for complete pull-up. For example, a fitting that incorporates the present invention may use course pitch threads that provide sufficient axial displacement to achieve proper pull-up in a half turn. A typical prior art fitting by comparison is pulled-up with 1¼ to 1½ turns. Nothing however prevents the designer from making the thread pitch any value suitable to a particular application, as there are other techniques to avoid interchange issues. Therefore, the one-half turn for pull-up is just one example of a variety of design choices available.
The central body bore 58 is preferably although not necessarily formed with a slight radially inward taper a relative to the longitudinal axis X ( FIG. 1 ) of the tube end 13 such that the diameter of the bore 58 decreases radially in the axial direction towards the counterbore 60 . For example, this taper may be about 2° to about 4°, although the selected angle is not particularly critical. The bore 58 diameter at the counterbore shoulder is just slightly less than the outer diameter of the tube end 13 . In this manner, the tube end 13 has a slight radial interference fit of a few thousandths of an inch for example with the bore 58 . This interference between the bore 58 and the tube end 13 provides an anti-rotation action to help prevent the tube end 13 from rotating during pull-up. This also reduces residual torsion stress that may be induced into the tube end due to rotation of the tube gripping element ( 80 ) during pull-up. The tube end 13 does not necessarily have to bottom completely against the counterbore shoulder 60 . This is because the interference fit helps provide a good primary seal between the bore 58 and the tube end 13 . The interference fit also helps improve the tube grip by the tube gripping element ( 80 ) by axially holding the tube end stationary during pull-up so that the full axial displacement of the tube gripping element ( 80 ) is used for proper deformation and tube grip rather than any lost axial motion or movement of the tube end during tightening. The taper of the bore 58 may extend gradually along its entire axial length or a shorter axial portion adjacent the counterbore 60 .
The nut 52 includes a first central bore 70 having a first diameter D 1 relative to the longitudinal axis of the fitting 50 . The nut 52 also includes a second bore 72 having a second diameter D 2 relative to the central longitudinal axis of the fitting 50 . In this embodiment, the diameter D 2 is less than the diameter D 1 . Furthermore, the diameter D 2 is sized so that the bore 72 defines a generally cylindrical wall that receives the tube end 13 ( FIG. 2 ). The first bore 70 terminates at a location that is axially spaced from the nut back end 74 to form a trepan 75 , such that the nut 52 includes a radially inwardly extending collar 76 . The collar 76 is generally defined by the back end wall 74 of the nut 52 , the smaller diameter bore 72 and the larger diameter bore 70 .
In accordance with a significant aspect of the invention, the nut 52 includes a tube gripping device 80 that extends axially inwardly in a somewhat cantilevered fashion from the collar 76 . The tube gripping device in this example is in the general form of a gripping ring 80 and includes an inner bore 82 that defines a substantially cylindrical wall that closely receives the tube end 13 ( FIG. 2 ). The diameter D 3 of the bore 82 may be the same as or different from the diameter of the second nut bore 72 . The cylindrical wall that defines the gripping ring bore 82 extends axially from a tapered front or nose portion 84 of the gripping ring 80 . The nose portion 84 includes an axially tapered outer surface 86 that increases in the radial dimension towards the back end of the ring 80 . The tapered outer surface 86 extends from a generally radial front end 85 of the gripping device 80 . This generally radial front end 85 joins to the inner cylindrical bore 82 at a preferably sharp corner 87 . Alternatively, however, there may be provided a circumferential recess or step or notch or other geometry (not shown) in the front end of the ring 80 having a diameter that is somewhat larger than the diameter D 3 and axially extending from the front end 85 towards the back end 74 of the nut 52 .
The tapered surface 86 joins the front end 85 preferably by a radius portion 89 and at its axial opposite end by a radius 86 a to a generally cylindrical portion 91 , which in turn joins via a radius 93 to the trepan 75 .
It is noted at this point that the various geometry characteristics of the tube gripping device 80 (such as, for example, the various recesses, notches, tapered portions, radius portions and so on) are selected so as to effect an appropriate radially inward hinging action as will be further explained hereinafter. Accordingly, the geometry of a tube gripping device 80 will be determined by the characteristics of the material of the tubing such as hardness and the fitting components, the dimensions of the tubing and the required tube grip and seal performance needed for a particular application. Therefore, the specific embodiments illustrated herein are intended to be exemplary in nature and not limiting as to the geometry of the tube gripping device. The above referenced patents for the two ferrule fitting also illustrate additional geometry variations to facilitate the hinging effect to obtain a desired tube grip.
In accordance with another aspect of the invention, the tube gripping device or ferrule 80 is attached to the female threaded nut 52 by a thin frangible web portion 95 . This web portion breaks (as illustrated in FIG. 2 ) when the ferrule 80 cams initially against a camming surface ( 88 ) during pull-up so that the tube gripping device or ferrule becomes a separate piece and functions with the nut and body in effect as a single ferrule fitting. The separated ferrule 80 has a back end 150 that is axially driven by a radially inwardly extending wall 152 of the nut 52 that serves as a drive surface for driving the ferrule 80 forward against the camming surface for completing an initial pull-up. The frangible web portion 95 is preferably designed so that upon separation of the device 80 from the nut 52 , the surface 95 a that is exposed along the break line does not interfere with the drive surface 152 of the nut during further pull-up to complete the assembly. As used herein, the terms “tube gripping device” and “ferrule” or “single ferrule” are used interchangeably when referring to the device 80 after separation from the nut 52 .
The ferrule 80 is machined with the frangible web 95 portion by forming a radial groove 154 that is angled generally toward the inside of the female threaded nut 52 . This groove 154 forms the back end 150 of the ferrule 80 and also the radial wall 152 of the nut that drive the ferrule axially against the camming surface after the ferrule 80 separates from the nut 52 . Preferably but not necessarily the wall 152 and the back end 150 are machined at an angle of about 75° or so relative to the tube bore axis X, although this angle may be different depending on the particular application. These surfaces 152 and 150 may be contoured to reduce galling and torque if so required.
With reference to FIGS. 1 , 2 and 3 , the tapered nose portion 84 initially engages an axially tapered camming surface 88 that forms an opening to the tube bore 58 in the main body 56 . The tapered camming surface 88 is a surface that joins the bore 58 wall to the back end wall 90 of the body 54 . This camming surface 88 is characterized by a generally frusto-conical contour. However, the shape of the surface 88 may be selected from other shapes depending on the particular ring deformation and tube gripping characteristics required for the fitting 50 in a specific application.
Upon a completed pull-up, the back end 90 of the body 54 contacts the trepan 75 which serves as a positive stop against over tightening. Should remakes be desired, the back end 90 may be axially spaced from the trepan 75 upon a completed first pull-up. Proper pull-up in this case may be verified using a gap gauge or other suitable technique, as is known.
The tube gripping ferrule 80 is shaped to effect several important functions of the fitting 50 . The ferrule 80 must, upon proper pull-up, provide a fluid-tight primary seal against the tapered camming surface 88 . This seal may be a primary outer seal for the tube fitting 50 , or may be in effect a secondary or back-up seal to any seal formed between the tube end 13 and the body 54 , for example along the bore wall 58 and/or the counterbore 60 . The separated ferrule 80 also will form a primary seal at the location where the ferrule 80 bites into the outer surface of the tube end 13 in the area where the cylindrical bore 82 of the ferrule 80 engages the tube end outer surface. Again, this primary seal may in effect be a back-up or secondary seal to any seal formed by the tube end 13 against the body 54 . In any event, the ferrule 80 must form primary seals against the camming surface 88 and the outer surface of the tube end 13 . In addition, the ferrule 80 must adequately grip the tube end 13 so as to maintain seal integrity under pressure, temperature and vibration effects, and to prevent the tube end from separating from the fitting under such circumstances.
In order to achieve a fluid-tight seal and tube gripping action, the ferrule 80 is designed to be plastically deformed and swaged into the tube end upon completed pull-up, as illustrated in FIG. 3 . This result is achieved by designing the ferrule 80 to have a hinging action whereby the tapered nose portion 84 is not only driven axially forward as the nut 52 is threaded onto the body 54 , but also is radially displaced or driven into engagement with the outer surface of the tube end 13 wall. The forward end 92 of the nose portion 84 is thus compressed and embedded into the tubing wall with a resultant stress riser or bite in the region designated 94 in FIG. 3 . The front end bite 94 produces a generally radially extending wall or shoulder 99 formed out of the plastically deformed tube end material. The shoulder 99 engages the embedded front end 92 of the gripping ring 80 to thus form an exceptionally strong mechanical resistance to tube blow out at higher pressures. The embedded front end 92 thus provides both an excellent seal and a strong grip on the tube end 13 . The ring 80 is further designed to exhibit the aforementioned radially inward hinging action so as to swage or collet the cylindrical wall 82 against the tube end at a location axially adjacent or spaced from the stress riser bite 94 and generally designated with the numeral 96 . This swaging and collet effect substantially enhances the tube gripping function and serves to isolate the embedded nose portion and bite 94 from the effects of down tube vibration and also temperature changes.
Although the present invention is described herein in the various embodiments as effecting an embedded nose portion and attendant swaging action, those skilled in the art will appreciate that in some applications such rigorous design criteria may not always be required, particularly for fittings that will be exposed to moderate temperature, vibration and pressure effects. Therefore, the additional design aspects of the nut, body and gripping ring set forth herein as preferred embodiments should therefore not be construed in a limiting sense but rather as selectable enhancements of the basic concepts of the invention to be used as required for particular applications.
In order to achieve the desired swaging action and tube grip, the ferrule 80 is designed to exhibit the hinging action that allows the tapered nose portion 84 and the central or mid-portion (as at the region of the cylindrical bore 82 or the region designated 94 ) of the gripping ring 80 to be radially inwardly compressed as it engages with the tapered camming mouth 88 of the body 56 . This hinging action is also used to provide a significant radial displacement and compression of the cylindrical wall 82 to swage a central or mid-portion of the ferrule 80 body onto the tube end 13 axially adjacent to the stress riser 94 . In the embodiment of FIGS. 1-3 , the hinging action is facilitated by providing a preferred although not required radial inner circumferential notch 98 that is axially positioned between the cylindrical portions 72 and 82 . The notch 98 is suitably shaped to permit the ferrule 80 to plastically deform and collapse in a controlled manner so as to radially compress the cylindrical wall 82 against the tube end with the desired collet effect. The particular geometry of the gripping ring 80 will thus be designed so that as the nut 52 is further threaded and tightened onto the body 54 after the ferrule 80 separates, the ferrule 80 hinges and plastically deforms to grip the tube end and to seal both against the tube end and the tapered camming mouth 88 . Standard design procedures such as Finite Element Analysis may be used to optimize the geometry of the ring 80 based on variable factors such as the tubing material, tubing hardness and wall thickness, and required pressure, temperature and vibration performance characteristics.
Proper deformation of the ferrule 80 may further be controlled by selecting an appropriate contour for the tapered surface 88 . This surface engages the tapered nose of the ferrule 80 and therefore will in part determine the timing and manner of how the ferrule 80 hinges, compresses and plastically deforms to properly embed the nose portion to bite into the tubing and also provide the desired collet or swaging action. Furthermore, the contour of the camming surface 88 may be designed to achieve the desired seal between the ferrule 80 nose portion and the tapered surface 88 . This seal is important to the overall performance of the fitting, as is the seal provided between the ferrule 80 and the tube end 13 .
The nut 52 with its integral tube gripping ferrule 80 may be manufactured by standard machining operations, and will typically include a trepan operation to form the outer contour of the ring 80 . The other features of the nut 52 can be realized as well with known machining operations. Preferably but not necessarily the nut 52 includes wrench flats 102 to permit the user to tighten the nut 52 onto the body 54 . Those skilled in the art will readily appreciate that use of the fitting 50 only requires relative rotation between the nut 52 and the body 54 , such that either component or both may be rotated as required during a pull-up operation.
We have found that it is highly desirable for the camming surface 88 to form a camming angle .theta. of about 35°-60° relative to the longitudinal axis X of the fitting 50 and tube end 13 . More preferably the angle .theta. of the camming surface 88 should be 40°-50°, and most preferred the angle .theta. should be about 45°. This range of angles for the camming surface 88 differs dramatically from commonly used metal ferrule-type tube fitting designs. Commonly used tube fittings have camming surface angles in the range of 10°-25°, which is a substantially shallower angle compared to the present invention. The shallower camming angle is necessary in prior art fittings to have the ferrule slide a greater axial distance along the camming surface. This greater sliding action permits the tube gripping device to be more gradually radially deformed into the tube end to form a gripping action or bite on the tube. This is especially the case for stainless steel tubing. Prior tube fittings that included what might appear to be a steeper camming angle actually either rely on a shallow portion of the camming surface or do not produce a bite in the tubing, thereby limiting the pressure resistance of the fitting. The shallow camming angle of the prior art, however, compromises the ability of a single ferrule to form a dependable seal. In sharp contrast, the present invention utilizes a substantially steeper camming surface angle .theta., which permits the gripping ring nose portion 84 in effect to be coined into the camming surface 88 without substantial sliding action, thereby forming an excellent seal.
In the exemplary embodiments herein, the nose portion 84 includes the radius portion 89 that transitions to the outer tapered surface 86 . This outer surface 86 tapers generally at an angle that is not as steep as the angle of the camming surface 88 . The tapered outer surface 86 preferably tapers axially with an increasing radial dimension towards the back end of the gripping ring 80 . This tapered outer portion 86 contacts the camming surface 88 with, in effect, a generally narrow zone or line contact upon pull-up that has high stress and material coining to allow the front end of the gripping ring 80 to coin into the camming surface 88 . Therefore, the term “generally narrow line contact” is not intended to preclude an area of contact between the outer tapered surface 86 and the camming surface 88 , but rather more generally to the concept of a localized contact zone near or at the innermost extent of the camming surface 88 of high stress and material coining between the outer tapered surface 86 and the camming surface 88 . By “coin” is simply meant that the gripping ring 80 achieves a good metal to metal seal between the radius portion 89 and the camming surface 88 by forming a generally narrow circumferential line contact of metal burnished on metal to effect a gas tight primary seal between the tapered surface 86 and the camming surface 88 .
It is important to note that the use of a particular camming angle is not dependent necessarily on the contour of the surface 88 . In other words, the angle of interest is the angle at which the front end of the gripping ring 80 contacts the camming surface 88 to form a seal thereat. Thus, the camming surface 88 may indeed be made with a non-frusto-conical contour, but the seal is still formed by the front end of the ferrule 80 contacting a steep angled surface 88 . Additional compound angles or contours of the camming surface 88 may be used to better facilitate the hinging action and tube bite achieved by the ferrule 80 .
Whether the camming surface 88 is formed as a compound angled surface with additional angled portions that are steeper or shallower to facilitate the hinging action and bite of the gripping ring 80 into the tube end 13 , in accordance with this aspect of the invention, the sealing portion of the front end of the gripping ring 80 (in the exemplary embodiments the radius portion 89 ) forms the primary seal on a steep angled portion of the camming surface 88 , preferably a steep angled portion in the range of angle .theta. of about 35°-60° relative to the longitudinal axis X of the fitting 50 and tube end 13 , more preferably the angle .theta. of the camming surface 88 should be 40°-50°, and most preferred the angle .theta. should be about 45 at the location where the primary seal is to be formed. Preferably although not necessarily this primary seal is effected by a generally narrow line contact type engagement between the front end of the gripping ring 80 and the camming surface 88 .
The steeper camming surface angle has the additional benefit that the nose or front portion of the tube gripping device 80 may be formed with substantially more mass as compared to if the front portion had to engage a shallower camming surface angle as in the prior art single ferrule and gripping ring designs. This added mass, along with the hinging action, tends to position a substantially greater mass of material at or near the location of the tube bite 94 . This significantly strengthens the tube gripping device in resisting pressure and also strengthens the collet effect that isolates the bite from vibration and temperature effects, as contrasted to prior art single ferrule or gripping ring designs. The hinging action also results in the back end of the tube gripping device (i.e. the end opposite the nose end 84 ) from contacting the tube end, so that the entire tube gripping device is in axial and radial compression.
In general, for a tube gripping device such as a ferrule to embed into, bite and grip the tube end, the tube gripping device must be harder than the tube end. This is especially so for thick wall tubing. The greater axial movement of a ferrule in a shallow angle camming mouth of the prior art allows a ferrule to embed into a tube even when the ferrule is only moderately harder than the tube. Under these circumstances if the tube gripping device 80 were only moderately harder than the tube end, the device would be unable to adequately grip the tube for a steep angle camming surface because of the substantially shorter axial movement of the tube gripping device during pull-up caused by the steeper camming angle. However, in accordance with the present invention, by making the tube gripping device significantly harder than the tubing, a steeper angle camming surface may be used and is effective to cause the tube gripping device to adequately bite into the tube end to grip the tube.
The steeper camming angle .theta. of the present invention also results in a much shorter distance of axial displacement of the ferrule 80 during pull-up. Consequently, the nose portion 84 will need to be radially deformed and compressed into the tube end 13 with a much shorter axial displacement or sliding movement. In order to achieve the proper tube grip then, the ferrule 80 is preferably case hardened to a hardness of at least about 3.3 times harder than the tubing material. For example, if the tubing material is stainless steel, it may exhibit a hardness of up to about 200 Vickers. Therefore, in accordance with this aspect of the invention, when the fitting 50 is used with such hard materials, the tube gripping device should be hardened to a ratio of at least about 3.3 times harder than the tubing. More preferred, the tube gripping device should be hardened to a ratio of at least 4 times harder than the tubing. Still further, the entire gripping ring 80 need not be case hardened, but rather only the nose portion 84 may be selectively case hardened.
In accordance with this aspect of the invention, all or part of the nut 52 and body 54 may be through hardened or case hardened to increase the tube grip of the fitting 50 when used with harder tubing materials such as stainless steel. Suitable case hardening processes are fully described in U.S. Pat. Nos. 6,165,597 and 6,093,303 and copending patent application Ser. No. 09/494,093 filed on Jan. 28, 2000 for MODIFIED LOW TEMPERATURE CASE HARDENING PROCESS, issued to the assignee of the present invention, the entire disclosures of which are fully incorporated herein by reference. These processes produce a hardness of the tube gripping device of about 800 to 1000 Vickers or higher without compromising the corrosion resistance of the fitting. Other case hardening techniques however may be used as required. Case hardening of the tube gripping ring 80 allows the ring 80 to adequately grip and seal against tubing materials such as stainless steel including duplex stainless steel. The above referenced case hardening patents have an additional benefit of providing surfaces on the ring 80 that reduce or prevent galling between the ring 80 (which rotates with the nut 52 ) and the tubing.
Various lubricants may also be used with the tube gripping ring 80 to reduce galling and residual torsion such as, for example, PTFE greases, and greases containing molybdenum disulphide or tungsten disulphide.
Case hardening techniques typically will result in the entire nut 52 and integral tube gripping ring 80 to be case hardened. When the case hardening is performed on stainless steel, for example, as in the above referenced patents or patent application, an adherent oxide skin is formed. In another embodiment of the invention, a solid lubricant may be applied to the threads of the stainless steel nuts 52 to reduce friction and the hence pull-up torque during tightening. Any solid lubricant can be used for this purpose and many such solid lubricants are well known. A few examples are graphite, molybdenum disulfide, tungsten disulfide and UHMWPE (ultra high molecular weight polyethylene). These lubricants can be used neat, i.e. not combined with another material, or mixed with another material such as a resinous carrier or the like. In addition, they can be used in essentially any solid form including powders, granules and pastes.
Solid lubricants of this type are well known commercial products. Examples include Dow Corning® 321 Dry Film Lubricant available from Dow Corning Corporation of Midland, Mich. and Slickote® Dry Lube 100 available from Trans Chem Coatings, of Monrovia, Calif.
These lubricants can be applied by any standard method such as by hand, by aerosol or air spraying or by automatic equipment. Any coating thickness can be used which will provide lubricating properties. Solid lubricant thickness exceeding standard class 2 thread clearances are usually not required. If appropriate, the lubricant can also be heated to enhance its adhesion. For example, some lubricants, especially those supplied in a resinous binder, can be heated to effect cure of the binder. For example, Slickote® Dry Lube 100 can be heated following manufacturer's instructions to 300° F. for 1 hour, for example.
In a particular embodiment of the invention, a dry lubricant as described above is used on stainless steel nuts 52 which have been subjected to low temperature carburization using carbon monoxide as the carbon source. Stainless steel is stainless because of the thin, coherent chromium oxide film which inherently forms when the steel is exposed to air. Low temperature carburization of stainless steel parts, such as those made from AISI 316 and 316L stainless steel, usually leaves the part surfaces coated with a layer of soot. Before use this soot is usually removed by washing. When carbon monoxide is used as the carbon source in low temperature carburization, not only does soot form but in addition a heavy oxide film also forms. This heavy oxide film is considerably different from the coherent chromium oxide film which makes stainless steel stainless in that it is thicker and not coherent. Therefore, this film is also removed before use to uncover the part's carburized surface.
In accordance with this particular embodiment, this heavy oxide film is not removed before application of the solid lubricant. Rather, it is left on the carburized part surfaces, or at least the portions of the carburized surfaces to be lubricated. In accordance this particular embodiment, it has been found that the naturally porous structure of this heavy oxide skin acts as an anchor for binding the lubricant to the part surfaces. As a result, the lubricant is more adherent than would otherwise be the case, and hence is able to withstand repeated fitting remakes (i.e., loosening and re-tightening of the nut) without being removed.
FIG. 4 illustrates another embodiment of the invention in which all elements are generally the same as the prior embodiment with one variation. In the frangible web portion 95 , a stress concentrating notch 300 is formed therein. In this embodiment the stress concentrating notch 300 is formed as a generally tight radius that creates a thinner web of material 302 to promote a rapid clean break of the ferrule 80 from the nut 52 . The break thus occurs as a result of a minimal span of rotation of the nut 52 shortly past finger tight position. The shape of the break is also less ragged. Other shapes of the notch 300 may be used as required including elliptical, triangular and so on for example.
The invention has been described with reference to the preferred embodiment. Clearly, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. | A tube fitting for a tube end has a first coupling member and a second coupling member joined with the first coupling member. A tube gripping device is disposed between the first coupling member and the second coupling member such that assembly of the first coupling member with said second coupling member to a pulled-up condition causes the tube gripping device to be plastically deformed and swaged into the tube to grip and seal the tube. The first coupling member engages an internal surface of the second coupling member to provide an indication of completed pull-up. | 5 |
This application is a continuation of application Ser. No. 09/271,481, filed Mar. 17,1999, now U.S. Pat. No. 6,110,176, which is a divisional application of application Ser. No. 08,886,173, filed Jul. 1, 1997, now U.S. Pat. No. 5,913,859.
FIELD OF INVENTION
The present invention relates generally to methods and apparatus for recovering bone marrow from a patient and subsequent collection and storage. More specifically, the present invention relates to a method of obtaining bone marrow and bone marrow fluid from the jawbone of a patient with relative ease and minor discomfort before, during, or after dental procedures, such as the removal of impacted or redundant third molars or bicuspids for long term storage and/or for bone typing.
BACKGROUND OF THE INVENTION
There are a number of diseases in which the bone marrow is defective, such as aplastic anemia, some forms of leukemia, and deficiencies in the bone marrow caused by cancer treatments with drugs and irradiation. The treatment of choice for these diseases is bone marrow transplantation, provided a genetically compatible donor can be found. For instance, bone marrow transplants are significantly reducing the death toll from childhood leukemias.
Bone marrow, also called myeloid tissue, is a soft, gelatinous tissue that fills the cavity of the bones. Human bone consists of a hard outer cortex and a soft medullary cavity that contains bone marrow. Bone marrow consists of stroma, or supporting tissues which have spaces packed by blood cells. Bone marrow is either red or yellow, depending upon the preponderance ance of vascular (red) or fatty (yellow) tissue. In humans, the red bone marrow forms all of the blood cells with the exception of the lymphocytes, which are produced in the marrow and reach their mature form in the lymphoid organs. Yellow bone marrow serves primarily as a storehouse for fats, but may be converted to red marrow under certain conditions, such as severe blood loss or fever. At birth, and until about the age of seven, all human marrow is red, as the need for new blood formation is high. Thereafter, fat tissue gradually replaces the red marrow, which in adults is found in the vertebrae, hips, breast bone, ribs, and skull, and at the ends of the long bones of the arms and legs, other cancellous, or spongy bones, and the central cavities of the long bones. In mammals, blood formation in adults takes place predominantly in the marrow. Because the white blood cells produced in the bone marrow are involved in the body's immune defenses, marrow transplants have been used to treat certain types of immune deficiencies. The sensitivity of marrow to damage by radiation and some anticancer drugs accounts for the tendency of these treatments to impair immunity.
Bone marrow transplants can be divided into three groups according to the source of the marrow for transplantation. They are called autologous, syngeneic, or allogeneic. Autologous transplantation means that the bone marrow has been received directly from the recipient, and will be an exact genetic match. A syngeneic transplant comes from an identical twin of the recipient and will also be an exact genetic match. However, for allogeneic transplants, the bone marrow is provided by another person, and the possibility of exact genetic matching is very low.
It is reported that approximately 12,000 bone marrow transplants were performed in 1992, approximately half of which were allogeneic and half autologous. Autologous transplantation has grown significantly during the past several years as improvements in procedures are made. The number of patients receiving allogeneic transplants is also rising due in large part because donor registries have increased the number of readily available donors. Advances in bone marrow transplantation techniques will likely continue to expand the use of the bone marrow transplant procedure.
Generally, the recipient's sibling or parent will serve as the best source as the donor because of the high possibility of genetic matching. However, there are many cases where neither the parent nor the sibling will be a compatible genetic match for the recipient. There has been a recent increase in the use of bone marrow from unrelated donors which can provide genetic compatibility between the donor and recipient. This increase has been made possible through the existence of large bone marrow registries, such as the National Marrow Donor Program, and the American Bone Marrow Donor Registry. The drawback to these registries are the insufficient number of donors that genetically match closely enough with potential recipients to be of use.
The success of the bone marrow transplantation technique depends heavily on genetically cross-matching the donor marrow cells to those of the recipient to prevent rejection. There is a significant tendency for the recipient patient to reject an allografted marrow because parts of the donor marrow will attack their new host. There is an additional hazard because immune system cells in a marrow graft can react against the patient's tissues, causing serious and sometimes fatal graft versus host disease. The ability to accept a bone marrow transplant (graft) from a donor, is dependent on the recipient sharing all of the donor's histocompatibility genes. To avoid graft versus host rejection in the past, special immunosuppressive treatment has been given. The use of monoclonal antibodies to selectively remove harmful lymphocytes from the donor marrow has been successful in some cases to prevent graft versus host disease. However, the risk remains that unless the bone marrow source is from the patient himself, an identical twin, sibling, parent, or other genetically compatible donor, that the bone marrow transplantation cannot take place because it will result in graft versus host rejection, and the failure of the treatment, and possibly the death of the recipient.
Therefore, there is a significant need to collect and store genetically compatible bone marrow for use in cases where bone marrow transplantation is necessary to save the life of an individual. Because of the significant possibility that a donor cannot be found which is a close genetic match to the recipient, there is a need to collect and store an individual's own bone marrow while that individual is still healthy. If this is done, there will be a complete genetic match, and the dangers of graft versus host rejection will be eliminated which increases the success of the treatment.
The collection of bone marrow for transplantation purposes is usually accomplished by inserting a needle into a donor's hip or pelvic bone. Several small incisions are made in the pelvic area, and the needle is inserted through these incisions approximately 25 to 30 times to withdrawn the bone marrow from the bones. The extraction process typically lasts at least one hour or more, or until approximately 500 to 1000 milliliters of the donor's marrow is withdrawn.
The donor will fully recover in approximately a few weeks when all the donated marrow has been replaced within the body. However, the extraction process is painful and there is typically soreness around the incisions until healing can occur. Typically, the donors also feel fatigued for some time after the procedure. The side effects to having donated bone marrow can vary from donor to donor. Infection from the incision is always a possibility. Additionally, blood loss can also occur, and proper medical attention is required. It is recommended that donors routinely store supplies of their own blood for infusion during and after the extraction procedure in cases of emergencies.
Bone marrow can be obtained through biopsy or aspiration from the sternum or the calvarium in adults, and in long bones, such as the femur and tibia, in adolescents. Biopsy needles for extraction of solid bone marrow are known. Examples of such biopsy needles are U.S. Pat. Nos. 2,991,692; 2,426,535; 2,496,111; 4,272,676; 4,266,555; 4,543,966; 4,487,209; 4,840,184; and 4,922,602, which show the overall structure and orientation of the components. Needles used for aspiration of liquid bone marrow are disclosed in U.S. Pat. No. 4,469,109. Needles designed to both biopsy and aspirate bone marrow are disclosed in U.S. Pat. Nos. 2,496,111; 3,587,560; 5,012,818; and 5,357,974.
There is a need for bone marrow extraction techniques that avoid the considerable inconvenience, discomfort, and pain due to current bone marrow extraction procedures and aspiration methods. Therefore, there is also a need to provide a method and apparatus to obtain both solid and liquid bone marrow from a donor with minimal intrusion and pain. There is also a need for the bone marrow to be stored for later use and is accomplished with relative ease.
The present invention provides for a dental apparatus used for extracting the bone marrow that includes a means to bore a hole in the jawbone of a patient and to immediately collect the bone marrow in a specialized collection means all in one system. Another embodiment of the apparatus of this invention includes a bone marrow apparatus that has various sources of solution supply and collectors for the purpose of preparing the collected bone marrow for storage, preservation, and subsequent use.
The present invention provides methods and apparatus for the extraction of bone marrow from the jawbone of the donor, which will eliminate the problems often associated with obtaining bone marrow from conventional methods. It should be noted that literally millions of dental extractions of third molars and bicuspids in young, healthy adults and adolescents are performed each year. Thus, the collection, typing, and storage of bone marrow obtained during this procedure provides an immediate source of highly desirable autologous bone marrow for long-term storage. It also provides a means for obtaining allogeneic bone marrow for registry and storage in National Registries which will provide greater access for everyone to bone marrow of perfect or near-perfect genetic match to potential recipients.
The invention further provides a method for providing an easily obtainable source of bone marrow, that requires no hospitalization, minimal discomfort, and provides no scarring as is common in the conventional extraction procedures. It also provides for the ability of an individual to collect and store his own bone marrow before the onset of any disease, such as childhood leukemias, which usually occurs between the ages of 15 and 30.
SUMMARY OF THE INVENTION
The present invention provides embodiments directed to a novel and improved method and apparatus for bone marrow extraction. A method for extracting and collecting bone marrow from a jawbone of a patient comprises the steps of boring a hole in the jawbone to a depth sufficient to form a jawbone bone marrow extraction site, extracting the bone marrow from the jawbone bone marrow extraction site, and collecting and storing the bone marrow in a collection chamber.
The method may further comprise the step of infusing a solution into a void in the jawbone resulting from the bone marrow extracting step. The solution may be selected from the group consisting of anticoagulant containing saline solution and electrolyte solution.
The method may include the steps of mixing the bone marrow with a liquid to form a mixture, transferring the mixture to the collection chamber, and isolating the bone marrow from the mixture to form isolated bone marrow. The method may further comprises the steps of preserving the isolated bone marrow with a preservative to form preserved bone marrow and storing the preserved bone marrow.
Another method for extracting and collecting bone marrow from the jawbone of a patient comprises the steps of: boring a hole in the jawbone to form a jawbone bone marrow extraction site; introducing a biopsy needle into the jawbone bone marrow extraction site, wherein the biopsy needle is connected to a suction source; penetrating a medullary cavity of the jawbone bone marrow extraction site with the biopsy needle; collecting solid bone marrow through the biopsy needle; penetrating the medullary cavity with the biopsy needle; breaking marrow stroma with the biopsy needle; activating a pump to aspirate liquid bone marrow from the broken marrow stroma; and collecting the liquid bone marrow through biopsy needle.
This method may further comprise the step of selectively activating a valve to selectively generate suction in the suction tube.
Methods of the invention comprise the steps of withdrawing bone marrow from the jawbone of a patient and collecting the bone marrow in such a way as to eliminate bone marrow aspiration pain. The method also provides for the extraction and collection of the bone marrow for long-term storage and personal banking following dental extraction or surgery. The method employs extracting bone marrow by a simple intrusion into the donor's jawbone immediately before, during, or after a dental procedure.
A significant aspect and feature of the present invention is a method for extraction of bone marrow from the jawbone of young, healthy patients during dental procedures, including the removal of impacted or redundant third molars or bicuspids. This method allows for the ready accessibility of large quantities of bone marrow in multiple locations. An advantage to this procedure is that additional incisions, other than those already performed, are not necessary because access to the marrow is already present. Furthermore, because there is no need for additional incisions, virtually no additional pain or medical complications, other than that experienced by the routine dental procedure, is experienced by the patient.
According to this invention, the bone marrow can also be collection during other surgical procedures, such as dental implants. The anterior mandible is an extremely safe area to obtain bone marrow without risk to any other vital structures. Another area where large amounts of bone marrow are readily available, according to this invention, is the anterior boarder of the ramus of the mandible. The method also avoids the risk of visible scarring.
According to another embodiment of the present invention, the uses of bone marrow other than for storage includes use in bone regeneration procedures such as periodontal bone grafts, sinus lifts, and implant placement. Through the use of known multiplication procedures, this bone marrow can then be multiplied.
Another aspect of this invention allows for the genetic typing of the bone marrow collected to be put to other uses, such as cross-typing for organ transplants in traumatic circumstances.
An additional aspect of the invention is to treat the bone marrow before storage or transplantation in an effort to protect a patient from a relapse caused by undetected cancer cells.
Further treatment, when needed, of collected bone marrow encompassed by this invention includes the removal of blood and bone fragments. For instance, T-cell depletion can be used in allogeneic bone marrow to remove T-lymphocytes. Collected bone marrow can also be combined with a preservative, such as dimethyl sulfoxide (“DMSO”) before storage and stored in a liquid nitrogen freezer until the day of transplantation. This technique, known as cryopreservation, allows the bone marrow to be preserved for a long period of time.
Cryopreservation permits bone marrow extracted during adolescence to be preserved throughout the lifetime of the donor. Currently, bone marrow transplantation is not used routinely in elderly adults because of the high risk of infection caused by the use of immunosuppressant drugs in use today. Thus, the availability of autologous bone marrow high in stem cells opens the door for a wide variety of treatment options, including anemia and osteoporosis.
The present invention also provides an apparatus for carrying out the method of this invention. One embodiment of the apparatus of the present invention includes a bone marrow extraction apparatus that has various sources of solution supply and collectors for the purpose of preparing the collected bone marrow for storage, preservation, and subsequent use.
In another embodiment, a dental apparatus for extracting bone marrow from a patient comprises a housing, means attached to the housing for extracting bone marrow from an extraction site, and means for collecting bone marrow extracted from the extraction site.
The extracting means may comprise a solid bone marrow extraction portion, the solid bone marrow extraction portion including a first and a second end, the first end being for collecting bone marrow. The extracting means may also comprise a liquid bone marrow extraction portion comprising a first end and a second end, the first end being for breaking bone marrow stroma and aspirating the liquid marrow.
In another embodiment, the extracting means comprises a bur and the collecting means comprises a passage in the housing. The collecting means may include a vacuum in communication with the passage in the housing.
The dental apparatus for extracting bone marrow from a patient may also comprise means for breaking up extracted bone marrow.
In another embodiment, the dental apparatus for extracting bone marrow from a patient comprises a housing having a cavity, a hollow shaft disposed in the cavity and having first and second ends, a bur attached to the first end of the hollow shaft, a beveled gear attached to the second end of the hollow shaft, and a drive gear matingly engaged to the beveled gear. A first passage is defined in the housing and is in communication with the hollow shaft for passing irrigation fluid to the extraction site. A second passage is defined in the housing and is in communication with the cavity for passing bone marrow from the cavity to a collection device. A vacuum may be placed in communication with the second passage.
In a further embodiment, the housing of the dental apparatus has a detachable portion, and at least a part of the second passage is defined in the detachable portion of the housing.
In another embodiment, the hollow shaft has a circumferential outer surface, and a spiral cutting blade for breaking up bone marrow is attached to the outer surface of the hollow shaft.
The collection device may comprise a tube in communication with the second passage and a container connected to the tube. The tube may include a valve for controlling a flow of bone marrow into the container.
A source for irrigation fluid may be placed in fluid communication with the first passage. The walls defining the cavity may have ridges for breaking up bone marrow prior to passage of the bone marrow through the second passage.
Further features and advantages will become apparent from the following and more particular description of the preferred and other embodiments of the invention, as illustrated in the accompanying FIGS. 1 through 4 in which like reference characters generally refer to the same parts or elements throughout the views, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of one embodiment of the dental apparatus according to the present invention;
FIG. 2 is an enlarged, fragmentary sectional view of the embodiment of FIG. 1;
FIG. 3 is an enlarged, fragmentary sectional view of an alternative embodiment of the apparatus of the invention; and
FIG. 4 is an enlarged, fragmentary sectional view of an alternative embodiment of the apparatus of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates the principles and concepts of a bone marrow extraction apparatus well adapted for use according to the invention. Shown in FIGS. 1 and 2 is an apparatus 10 capable of boring a hole in a jawbone 13 and extracting bone marrow therefrom. The apparatus 10 comprises a housing 17 , structure 20 attached to the housing 17 for extracting bone marrow from an extraction site, and structure 23 for collecting bone marrow extracted from the extraction site.
The housing 17 has a cavity 26 . A hollow shaft 29 having a conduit 30 and first and second end portions 32 and 35 is rotatably mounted in the housing 17 with the end portion 35 being disposed in the cavity 26 . The end portion 32 includes a bur 38 having a cutting flute 39 for boring a hole in the jawbone 13 . A beveled gear 41 is attached to the second end portion 35 of the hollow shaft 29 . A drive gear 44 is matingly engaged to the beveled gear 41 . The drive gear 44 is connected by a shaft 47 to an electrical motor, a pneumatic motor, or other suitable equipment (not shown) for driving the drive gear 44 . The shaft 47 may be connected to the motor or other drive source by any feasible mechanical or other connection means. By engaging the shaft 47 , the drive source rotates the shaft 47 so as to cause rotation of bur 38 . As shown in FIG. 3, the shaft 47 may be adapted to be driven by a standard “E” motor.
The housing 17 has a first passage 50 in communication with the hollow shaft 29 . The first passage 50 is for passing irrigation fluid to the extraction site. The irrigation fluid passes through the passage 50 and then through the conduit 30 to the extraction site. The irrigation fluid cools the extraction site and adds liquid to the extracted fluids and solids to facilitate removal by suction. A source 51 (FIG. 1) of irrigation fluid may be connected to the housing 17 so that the source 51 is in communication with the first passage 50 . The housing 17 has a second passage 53 in communication with the cavity 26 . The second passage 53 is for passing bone marrow from the cavity 26 to a collection device 56 (FIG. 1 ).
A suction tube 57 may be connected to the second passage 53 for extracting solid bone marrow from the medullary cavity of the donor. The rotating bur 38 and the suction tube 57 are preferably detachably connectible to the housing. The housing 17 may be a hand-held power unit. However, while the housing 17 may be formed in a generally cylindrical handle-type configuration as shown in FIG. 1, such apparatus may be of other forms, including a pistol grip-type configuration (not shown).
Apparatus 10 may include structure for breaking up bone marrow into smaller particles prior to the entry of the particles into the second passage 53 . For example, a spiral cutting blade 59 may be attached to the outer surface of the hollow shaft 29 for breaking up particles while the hollow shaft 29 rotates. Additionally or alternatively, the cavity 26 may be defined by walls having ridges 62 . The ridges 62 break up the bone marrow into smaller particles as the particles pass through the cavity 26 into the second passage 53 .
As shown in FIG. 4, the housing 17 may have a detachable portion 65 . At least a part of the second passage 53 is defined in the detachable portion 65 . Alternatively, the second passage 53 may be connected to the outside portion of the housing 17 of FIGS. 2 and 4.
The suction tube 57 , which includes an integral valve 68 (FIG. 1 ), is attached to a vacuum source 71 (shown schematically in FIG. 1) at one end and a suction tip (not shown) at the other end. The integral valve 68 , which comprises a housing and a pivotal obturator, permits an operator of the apparatus to selectively produce suction through the suction tube 57 with one hand. See U.S. Pat. No. 5,295,830.
A vacuum source 74 (FIG. 1) withdraws solid and liquid bone marrow from the medullary cavity into the suction tube 57 , which transfers the solid and liquid bone marrow to the collection device 56 .
The apparatus 10 of FIGS. 1 and 2 could be used immediately before, during, or after a dental procedure or dental surgery. Thus, an adaption of the apparatus 10 described above which does not contain the rotating bur 38 is also in accordance with the present invention. Preferably, the rotating bur 38 incorporates an internal vacuum. More preferably, the configuration would be an entirely disposable unit designed to fit on a standard dental straight hand piece or to fit on a standard “E” motor, either air driven or electric.
A biopsy needle 85 , shown schematically in FIG. 1, may be used in conjunction with the apparatus 10 . One configuration for utilizing the biopsy needle 85 includes a tube 80 (FIG. 1) in communication with the valve 68 and the suction tube 57 . The biopsy needle 85 may be connected at an end of the tube 80 . The valve 68 may be used to control whether suction is produced through the tube 57 (and therefore the apparatus 10 ), the tube 80 , or, if desired, both the tube 80 and the tube 57 simultaneously. When suction is produced in the tubes 57 , 80 simultaneously, the biopsy needle 85 may be positioned adjacent the extraction site to provide extra suction and to otherwise assist the apparatus 10 in extracting bone marrow.
Alternatively, an end 90 of the tube 57 may be removed from the housing 17 . A biopsy needle may be attached to the end 90 of the tube 57 . The biopsy needle may then be positioned adjacent the extraction site to assist in bone marrow extraction. In this configuration, all suction would be provided by the biopsy needle, because the apparatus 10 would not be in communication with the vacuum source 74 .
A preferred embodiment has a rotating bur 38 that is oversized for vacuum collection. The rotating bur 38 may be made of, for example, carbides, stainless steel, or plastic, and comprises at least one large opening similar to internal irrigating burs used for implants, with a cuff as either an integral part of a disposal hand piece or attachable to the bur 38 , allowing free rotation of the forward portion only. The rotating bur 38 is connected to a vacuum hand piece similar to the housing 17 , such as disclosed in U.S. Pat. No. 3,863,635. The rotating bur 38 may also be contained within the suction tube 57 .
The liquid bone marrow can be obtained from dental extraction sites using a heavy metal blunt instrument following dental extraction to compress the bone alone and integrated vacuum to collect the bone marrow.
The apparatus 10 may include a solid bone marrow extraction portion having a first end and a second end. The first end is for collecting bone marrow. The apparatus 10 may also include a liquid bone marrow extraction portion comprising a first end and a second end. The first end is for breaking bone marrow stroma and aspirating the liquid marrow. Some conventional biopsy needles may be used to provide the solid bone marrow extraction portion and the liquid bone marrow extraction portion.
The apparatus of FIG. 2 may further comprise an elongated stainless steel solid marrow pushing probe to express a solid marrow specimen outside the cavity 26 after the procedure. (Not shown in FIG. 5.) One example is shown in U.S. Pat. No. 5,012,818.
The extraction of bone marrow from the jawbone during a dental procedure provides an advantage to the dental procedure alone in that it decreases the percentage of extraction sites experiencing dry sockets. This is due to the perforation of the compressed bone of the tooth socket.
A preferred embodiment of the present invention provides for a bone marrow extraction apparatus which effects the removal of bone marrow and bone marrow fluid from a donor at the jawbone and mixes the removed bone marrow with a suitable form of solution, such as a mixture of anticoagulant and saline or electrolytic solution. The bone marrow and bone marrow fluid removed from the donor are then transferred either into a cell separator or a suitable collection bag, such as the collection chamber 56 , so as to permit separation of the bone marrow and fluid for subsequent processing and long-term storage. The collected bone marrow may also be used for the subsequent reinjection into the donor in future bone marrow transplantation procedures.
In the removal of the bone marrow from the donor, a solution consisting of heparin or other anticoagulant compositions, together with a saline solution, can be mixed with the bone marrow and bone marrow fluid before, during, and/or after being transferred into separating or collecting means.
The collection device 56 may be a bag containing chemicals for preserving bone marrow. The chemicals may be in the bag prior to the withdrawal of bone marrow from the jaw of a patient. In this manner, after bone marrow has been collected, the device 56 can be stored cold directly. Additionally or alternatively, chemicals can be added to the collection device 56 during or after collection of bone marrow to preserve the bone marrow. Suitable means for adding chemicals to a container such as the collection device 56 are well known in the art and may include penetrable membranes at specific locations on the collection device 56 .
The collection device 56 is preferably collapsible so that air may be removed after collection has occurred. Removal of air increases the useful life of the bone marrow.
From the foregoing, disclosed is a bone marrow collection apparatus which is easily adapted to conventional dental or medical equipment. A technical advantage of the extraction-removing equipment of the invention is that bone marrow can be more quickly removed than conventional extraction procedures.
The dental apparatus according to the invention is not limited to that specifically disclosed and may comprise tools other than that described herein. Andre Schroeder et al., Oral Implantology, pages 66-71, 118-151, 178-187, 202-217, and 228-243 (George Thieme Verlag, 1988), discloses additional tools that are capable of boring holes in jawbones. Further, U.S. Pat. Nos. 4,564,374 and 4,982,379 discloses a device that are capable of extracting both solid and liquid bone marrow. Adaptations of these devices may also be used in accordance with the present invention.
In a preferred method according to this invention, a donor is positioned in a dental examination chair. A hole is formed in the donor's jawbone before, during, or immediately after a conventional dental procedure using the boring portion or bur 38 of the apparatus according to the present invention. The boring portion or bur 38 can also be used to break up the bone marrow after a hole is formed. The area of marrow extraction is sterilized with an antiseptic solution. The entire procedure of obtaining both solid and liquid bone marrow can be accomplished in less than one to two minutes. The large lumen is introduced into the previously made bore hole and pushed into the medullary cavity. The large lumen is pushed further into the marrow cavity with forward pressure in order to obtain solid marrow. The large round bur can simultaneously irrigate and vacuum.
Liquid bone marrow sample is obtained by applying a negative pressure in the small lumen of the suction tube 57 using a vacuum source (not shown). This results in the breaking of marrow stroma and the release of fluid marrow.
Collagen resorbable membranes or plugs can be used to cover the access to the bone marrow. This assures replacement of bone with bony and not fibrous tissue.
In summary, this invention overcomes many inconveniences of the existing bone marrow extraction methods. First, this is a new method of obtaining both solid and liquid marrow in a single procedure. Secondly, the apparatus allows reducing the procedure of extracting and collecting into one step.
While the invention has been described in detail in the drawings and foregoing description, the same is to be considered as illustrated and not restrictive in character. It being understood only in the preferred embodiment and methods have been shown and described, and all changes and modifications that come within the spirit of the invention are desired to be protected. | Methods and apparatus are presented for extracting and collecting bone marrow from the jawbone of a patient before, during, or after dental procedures. The method and apparatus further provides a readily accessible, and easily harvested, source of bone marrow without the drawbacks of current extraction methods. | 0 |
[0001] This application claims the benefit of U.S. Provisional Application 60/966,651 filed Aug. 29, 2007.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to removing coke from a coker drum in a delayed coker unit. In particular, the present invention relates to coke cutting using high pressure water jets. Delayed cokers are operated in a semi-batch mode, with at least two drums. While one is being filled and coked, the other is de-coked. During the coking cycle, the drum is gradually filled with liquid feed at about 900 degree F. from a nozzle at the bottom of the drum, vapor product leaves the drum at the top, and coke forms inside the drum as the result of a complex solidification process. During de-coking cycle, the drum is first cooled by steam or water. After cooling and draining, a high pressure rotary jet is used to cut the coke loose, which is removed from the bottom of the drum. Since the high pressure water jet literally cuts through the layers of coke in the coker drum, the process of emptying the coke drum using the water jet is commonly called “coke cutting.”
[0003] Delayed cokers are recognized as one of the primary capacity bottlenecks at a refinery. Quenching, cutting and removal of the solid coke are the limiting steps of the coker operation. Currently there are very few measurements on a coker for operators to determine actual condition of de-coking operation and make real-time adjustment. The coke cutting and removal in most delayed cokers is a labor-intensive manual operation.
[0004] The cutting process relies heavily on the person operating the hydraulic decoking system. The coke cutting operator uses the rotary water jet to cut through the coke, starting from the top of the drum, removing one layer of coke each time, then moves the jet downward to cut the next layer. The operator determines when to move to next layer either by fixed-time routine or by listening to the air-born sound emitted from the top opening of the drum. Very often, more round trips of the water jet are performed over the layer just to increase the probability of complete removal of all the coke in that layer. When the operator could not determine the cutting condition from his own sensing capability (e.g., when moved from the vicinity of the drum opening to an isolated control room), it is not only very challenging to cut coke efficiently but also increases the probability of equipment failure such as bending damage of the jet bit due to coke fallouts from residual coke left behind (i.e. above the water jet cutting tool).
[0005] The operator is responsible for controlling or driving the rotary water jet down and up the coker drum until he thinks that all the coke inside the drum has been removed. The operator becomes the sole decision maker during the cutting operation and so the potential for error is very high. In addition, the cutting time and quality also vary from operator to operator and from cycle to cycle. To make the coke cutting operation more efficient, more consistent, and safer, there is need to monitor the coke cutting operation with sensors and a computerized intelligent system to assist operators in coke cutting.
[0006] The present invention uses acoustic approach to measure the drum wall vibration caused by the coke cutting, and convert the vibrational signature measurement into an intelligent decision-making system which is capable of classifying the different conditions of the cutting operation in real-time. This intelligent capability leads to partial or full automation of the coke cutting operation. The invention allows for very efficient coke cutting, largely eliminating the possibility of errors that arise from misjudgments of the coke cutting operator. The invention converts coke cutting from an arbitrary process lacking of controls into a very reliable and consistent operation. This translates into safer operation, lower operational costs and higher productivity.
SUMMARY OF THE PRESENT INVENTION
[0007] A coker drum or vessel experiences a variety of vibrations as a result of high pressure water jets used to empty the coker drum when it is filled with solid coke material. The invention is a method that allows for automated control of the high pressure water jets by correlation of coke cutting with the vibrational signature measured at the coker drum wall. Acoustic transducers, or other non-contact method such as an optical method, mounted on exterior surface of the coke drum, are used to measure the vibrations of the coker drum wall as a result of the high pressure water jets. The wall vibration signature when the high pressure waterjets strikes the inside of the coker drum wall is significantly different from that produced when the jets cut through the coke material. For example, the vibration levels at certain resonance frequencies of the drum wall, when the jets hit the interior wall, is much higher than that when the jets hit the coke. In this way we can distinguish between an area of the coker drum that is empty of coke and an area of the coker drum that contains a layer of coke. The invention is a method that decides when a section of the coker drum is completely free of coke based on the measurement and analysis of the vibration signatures and thus it can be used to drive the high pressure water jets into a different position in the coker drum where coke is still present. The process would continue until the coker drum has been completely emptied of coke.
[0008] The invention eliminates the dependency of the efficiency of coke cutting on the skill level of the water jet operator since the method allows for automated control of the coke cutting operation. As a result, coke cutting efficiency and consistency are highly improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shows a typical coke cutting of a delayed coker.
[0010] FIG. 2 shows the time-frequency analysis of the vibrational signal of the coker drum wall during coke cutting. The plot on the top represents the time domain data and the plot in the bottom represents the frequency domain data. The area in parenthesis represents the removal of a 10 foot deep layer of coke.
[0011] FIG. 3 shows a detailed FT (Fourier Transform) analysis for the removal of a 10 feet deep layer of coke during the cutting process.
[0012] FIG. 4 shows a band-filtered time domain vibrational signal. First plot represents the original signal without filters, the second and third plots show filtered signals in the frequency ranges indicated.
[0013] FIG. 5 shows the vibration energy of the vibration mode of 1800 Hz.
[0014] FIG. 6 shows a schematic diagram of the system of the present invention.
[0015] FIG. 7 shows a schematic for magnetically coupling accelerometer to delayed coking drum.
[0016] FIG. 8 shows a schematic wherein the accelerometer is replaced by a high reflectivity diffuse reflector.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] FIG. 1 illustrates typical coke cutting process of a delayed coker. First, the operator uses the high pressure water jets to cut a pilot hole along the center of the drum, through which loose coke can easily fall out of the drum. Then the operator uses the rotary jets to cut through the coke; starting from the top of the drum, remove one layer of the coke each time, and lower the jets to cut the next layer. When cutting into the coke, the high pressure water jets impact on and fracture the coke mass. The impacts and fractures produce stress waves that propagate through the coke layer toward the drum wall. Since the coke layer is highly dissipative due to grain or void scattering and absorption, the stress waves become weak when they reach the wall. As a result of coke attenuation, the vibration of the drum wall induced by the stress waves, is relatively small. The thinner the coke layer gets, and the less attenuation of the stress waves through the layer is, the stronger the wall vibration becomes. When the jets directly impact on the wall after complete removal of the coke layer, the wall vibration level reaches the highest. Because the jet impact behaves more or less like a high pressure impulse, multiple vibration modes of the drum wall are excited. The wall vibration at the resonance frequencies associated with those modes become dominant in the signal. This qualitative description of the drum wall vibration characteristics becomes clear when the example of actual vibration signals are acquired during the coke cutting operation of a refinery delayed coker and analyzed, as shown in the next section.
[0018] Vibration signals of coker drum wall during coke-cutting operation of a refinery coker were acquired and are shown in FIG. 2 . The vibrational signals of the coker drum, when the water jet drill impinges directly on the coker drum wall, is very different from the vibrational signal of the coker drum when the water jet drill impinges into a layer of coke. A time-frequency analysis of the vibrational signal of the coker drum wall, as shown in FIG. 2 , revealed two very distinct vibration modes when the water jet is striking the coker drum wall directly. For this particular coker drum, the first mode is observed at about 1800 Hz and the second mode is observed at around 3600 Hz. These vibrational modes are not observed or much weaker when the water jet drill strikes a layer of coke, as shown in FIG. 2 . The frequencies and levels at those vibration modes are similar from layer to layer as long as the layer of coke is completely removed and the water jets impacting on the wall directly. The invention correlates the analysis of the vibrational signal of a coker drum during the coke cutting process with the decoking condition at any given time.
[0019] A detailed FFT analysis of the time progression for the removal of a 10-foot layer of the coke is shown in FIG. 3 ; six different stages are identified:
[0020] (1) The water jet hitting the layer of the coke without reaching the drum wall—no or negligible modal vibrational signal observed;
[0021] (2) The water jet starts penetrating deeper into the coke layer and just begins to reach the coker drum wall at discrete locations—modal vibration signal begins to emerge;
[0022] (3) The frequency of the water jet impact on the coker drum wall increases and thus the modal vibration signal at the coker drum resonance frequency increases as well;
[0023] (4) The layer of coke is almost completely removed and thus the high intensity of the modal vibration signal;
[0024] (5) Modal vibration reaches its maximum since the entire coke layer has been removed and the water jet is striking the coker drum wall directly;
[0025] (6) The water jets start moving downward into a new layer of coke and the intensity of the modal vibration signal decreases.
[0026] To extract the modal vibration at 1800 Hz and 3600 Hz and improve signal to noise ratio, two digital band filters, with frequency bands of 1500-2300 Hz and 3000-4500Hz respectively, were applied to the original vibration data. The filtered signals are shown in FIG. 4 . The results show that the two modal vibration signals preserve the cutting signature with high fidelity showing a similar temporal pattern to the original signal. Therefore, either of these frequency bands may be used or both of them may be combined for coke cutting monitoring. The higher frequency mode may be preferred because of low background noise contamination.
[0027] To derive a single parameter for monitoring the coke cutting condition, a moving window of fixed length is applied to the band-filtered modal vibration signals and the total vibration energy (sum of the squared signal amplitudes) within the window is computed as a function of time. FIG. 5 shows the vibration energy of the first vibration mode of 1800 Hz. It is clear that the vibration energy reaches a maximum level when the coke layer is completely removed and the water jets are directly impacting on the coke drum wall. The maximum vibration energy level appears to be quite similar for cutting of different layers, which provides a robust measure for decision making when the layer is completely removed.
[0028] The system of the present invention is a vibration data collection and signal analysis system as shown in FIG. 6 . It consists of one or more vibration receivers ( 1 ), a signal conditioning unit ( 2 ), an analog-to-digital converter unit ( 3 ), and a computerized signal processing unit ( 4 ). If a single receiver is used, the preferred placement of the receiver is on exterior wall of the coker drum above the maximum level of the coke. For multiple receivers, one of them is placed on the exterior wall of the coker drum above the maximum level of coke, and others are placed on the exterior wall of the drum with preferably equal distance between two adjacent receivers. The vibration receivers ( 1 ) measure the amplitude of the wall vibration of the coker drum, x(t), where t is the time. The analog vibration signal from the receivers ( 1 ) is conditioned (for example, low-pass filtering and amplification) by the signal conditioning unit ( 2 ), and converted to digital signals, x(n), by analog-to-digital converter unit or ADC ( 3 ). Then the digital signal is sent to a computer system ( 4 ) for further on-line signal analysis. The output of the signal analysis in ( 4 ) is the value of a coke-cutting monitoring parameter, C, and C takes on the value of either one or zero, where C=1 indicates that the coke layer is completely removed.
[0029] The first step in the signal analysis is application of band filters to extract the modal vibration signal, the portion of the measured signal that is associated with the certain mode of wall resonance. For example, the vibration signal amplitude of mode m with a mode frequency f m is extracted approximately with an FIR (finite impulse response) filter as follows:
[0000]
y
m
(
n
)
=
∑
k
=
0
N
a
km
x
(
n
-
k
)
(
1
)
[0000] where n is the time step, x(n) is original signal, y(n) is the filtered signal of the mode m, a km is the coefficients of the band filter, N is the order of the filter. Other type of filters such as infinity impulse response filters can also be used. The extraction of the mode can also be done in the frequency domain. For a specific coker drum operated at a given condition, the vibration modes and mode frequencies are relatively constant, though small variation with time is expected due to normal fluctuation of operating condition such as wall temperature. Design of a proper band filter for a given mode is done off-line by acquiring wall vibration during coke cutting and examining the frequency spectrums to identify the vibration modes, and mode frequencies. To account for variation of the mode frequencies due to fluctuation in operation condition, a frequency band is selected for each mode with a center frequency equal to the nominal mode frequency value from off-line frequency analysis. Then the filter coefficients are determined by the lower and upper cutoff frequencies identified for the mode. For multiple modes, multiple band filters with different frequency bands are applied. The next step is to compute the vibration energy, z m , in the mode m with a moving window method as follows:
[0000]
z
m
(
n
)
=
∑
k
=
p
n
y
m
2
(
k
)
(
2
)
[0000] where n is current time step, and n-p is the length of the moving window. The window length should be greater than the period of the vibration of the given mode (inverse of mode frequency) and typically sufficient long to include several periods of the mode vibration. The vibration energy can also be estimated in frequency domain. Then the third step is to compute the conditional probability of occurring of the event that current layer of coke is completely removed, given the vibration measurements. One approach to estimate the conditional probability is to use the following approximation:
[0000]
P
(
E
/
Z
m
)
=
N
E
N
T
(
3
)
[0000] where E denotes the event of empty coke, Z m is the data set of z m (n), z m (n−1), . . . z m (n−q), N T is total number of data points in Z m which is equal to n−q, and N E is total number of data points in Z m that is equal to or greater than a threshold of modal vibration energy, z threshold . When P is equal to or greater than a probability threshold, P threshold , then the current layer is estimated to be completely removed, and monitoring parameter of coke cutting, C, is, set to one. Otherwise, the value of C remains the zero. Once the value of C is set to zero, the signal analysis process discussed above is reset and repeated for coke cutting of next layer. The parameters N T , and threshold values are selected off-line by acquiring and examining vibration signals during coke cutting and calibrated against the condition of coke cutting at different stages. Alternative methods may be used to determine the value of monitoring parameter C. For example, temporal change of vibration energy z m is also a good indicator of coke cutting condition. When the coke layer is completely removed, z m becomes steady and change with time is small. Therefore a data set of Δz m (i.e, Δz m (n)=z m (n)−z m (n−1), Δz m (n−1)=z m (n−1)−z m (n−2), . . . ) can be used in estimating P(E/Z m ) in equation (3) instead of z m , and a threshold Δz threshold instead of z threshold .
[0030] The important parameters in the signal analysis includes the number of modes and modal frequencies, the coefficients of band filters, the window length of modal vibration energy computation, total number of data points in estimation of the conditional probability, the modal vibration energy threshold and probability threshold. The selection of those parameters may require calibration with vibration measurement and data analysis for a specific coker drum.
[0031] The invention monitors the vibrations in the coker drum wall and controls the rotary water jet drill accordingly based on the signal analysis as discussed above. The control of the water jet drill can be implemented with open or closed loop. With an open control loop, the computerized vibration data acquisition and analysis ( 4 ) is used to estimate the status of the coke cutting operation automatically, but adjustment of the jet drill can be made manually by an operator. For example, if the output of the system is a unit value of C, the operator will move the jet drill to next layer. Otherwise, he/she keeps the jet drill at the current layer for continuing cutting.
[0032] With a closed control loop, coke cutting operation can be made fully automated. The coke-cutting automation system may consist of one or more vibration transducers strategically located on the drum, a position sensor of measuring the position of the jet drill, an actuator that controls the movement of the jet drill, a computerized vibration data acquisition and signal analysis unit that continuously determines the vibration signature of the coke cutting and estimates the status of the cutting condition, and a controller and controlling algorithm that control the movement of the cutting jet (position and speed). The operation of the automation system can be described as follows:
[0033] (1) cut a pilot hole through the coke drum and lift the jet to the top of the drum
[0034] (2) lower the jet to the top coke layer and start the cutting while collecting the wall vibration data
[0035] (3) band-filter the vibration data with a pre-determined filter to extract modal vibration and calculate the modal vibration energy over a small moving time-window
[0036] (4) Computing the conditional probability of the event that coke layer is completely removed given the vibration measurements. If the estimate of the probability is below the pre-determined threshold, continue the cutting at the current position. If it is above the threshold, start lowering the cutting jet drill to the next coke layer
[0037] (5) continue step 3 and 4 until whole drum is cleaned.
[0038] Variation of the operation can be used to achieve the same goal. For example, instead of using time-domain band filter, short-time Fourier spectrum analysis can be used to extract the desirable signatures. There may be number of different ways to implement the automation process with the vibration signatures. For example, a fuzzy-logic controller may be considered for robustness.
[0039] The present invention includes a means to utilize low cost, low temperature, commercially available accelerometers to measure the vibrations of high temperature surfaces of the coker drum, thereby eliminating the need for significantly higher cost, high temperature accelerometers. The low temperature accelerometer and cable is attached to a rod whose opposite end is attached to a permanent magnet (see FIG. 7 ). The magnet is used to affix the rod-accelerometer assembly to the ferromagnetic reactor wall. The permanent magnet material should have high Curie temperature, remanence, and coercivity, and a low value of thermal loss coefficient. Cast and sintered Alnico 5 are examples of suitable materials for use on reactor surfaces of 1000° F. or less. Sintered Alnico 5 is preferred but is more expensive. The magnet preferably has a geometry with multiple poles with ground faces which serve to provide multiple points of contact on reactor surfaces which may neither be flat nor smooth. The length of the rod separating the accelerometer and permanent magnet may contain cooling fins. The minimum length of the rod is determined by the greater of the reactor insulation thickness and the length required to reduce the temperature at the accelerometer to the maximum operating temperature of the low temperature accelerometer. The material of the rod may be thermally insulating or conducting or a combination of materials. The material is preferably of low density so as to minimize the torque on the magnet that would tend to reduce its holding power onto the reactor wall.
[0040] The above method means may also be used, with little modification, to improve the optical method for remote, non-contact measurement of the vessel surface vibration. In this embodiment, the accelerometer is replaced by a high reflectivity diffuse reflector as shown in FIG. 8 .
[0041] This embodiment has two advantages. Firstly, the measurement means permits the vibration spectra of the vessel surface to be measured by the laser in the case that the surface is covered by insulation. Secondly, it minimizes the amount of thermal insulation that must be removed in order for the incident laser radiation to impinge on the surface. This is particularly important if the remote laser and the point on the surface to be measured are at substantially different elevations resulting in a large angle of incidence required for the laser to reach the surface and for thick layers of insulation. Thirdly, the diffuse reflector increases the amount of reflected laser light that is dynamically Doppler shifted by the surface vibrations, thereby resulting in a more reliable measurement of the surface vibrations. | The present invention is a method to remove coke from a coker drum. The invention includes the steps of impinging fluid from a fluid jet on the inside surface of the coker and then determining the vibration signal of the coker drum. The signal is then transformed to determine the amplitude versus frequency by a Fourier Transform of the vibration signal. The amplitude change of the vibration signal as it goes through a maximum, determines when the coke layer has been cut. The fluid jet is lowered into a new layer of coke. | 2 |
FIELD OF THE INVENTION
The invention concerns a microfluidic arrangement for extracting and optionally processing a flowable extract from a sample and for transferring the extract to a microfluidic chip. Moreover, the invention concerns a lab-on-a-chip system with such a microfluidic chip including the microfluidic arrangement.
BACKGROUND OF THE INVENTION
The invention therefore lies in the technical field of extraction of biochemical or chemical analytes, especially DNA/RNA material, protein, cells and/or bacteria from samples, especially solid sample, such as soil samples, foodstuffs and the like, with subsequent reaction. For example, in the extraction of DNA/RNA from samples, the sample is combined with an extraction buffer in known fashion, mixed, and then filtered. The extract or filtrate is then usually subjected to further processing in a suitable container. This can be a molecular biology process (such as labeling during an immunoassay) or lysis during a DNA assay.
While the further processing of the extract on microfluidic scale is known—and this refers to filtrate amounts of less than 5 milliliters, typically on the order of 1 μl to 1000 μl and especially less than 500 μl—the extraction itself is carried out manually in several steps on a macroscopic or laboratory scale (filtrate amounts in the multiple-digit milliliter to liter range). A particular problem is the transfer of the extracted sample material to the microfluidic chip. In this way, a not inconsiderable loss of sample material can occur, as well as a risk of contamination for the transfer from one vessel to another. Moreover, it is not easy to introduce the extract into the chip without loss of fluidic control. Not least, extraction on a laboratory scale is costly and presupposes large quantities of the starting substances, especially the sample material.
A step in the direction of extraction is an extraction system as is described, for example, in the publication “Sample Preparation for the Analysis of Gluten from Foodstuff in a Modular Chip-Platform” on the occasion of the 10th International Conference on Miniaturized Chemistry and Life Science, from 5 to 9 Nov. 2006 in Tokyo, Japan. This extraction system uses a method based on a peristaltic or constricted tube pump for mixing the sample with an extraction buffer. To separate the undissolved sample components, a centrifuge is used instead of a filter. Efforts to reduce the centrifuging itself to the scale of microfluidic chips are described more closely in DE 10 2006 003 532 A1. The centrifuge is connected at the inlet and outlet side by a fluidic connection piece to a microfluidic chip.
Yet the technical expense of centrifuge extraction is very high. The centrifuge known from the aforementioned publication contains very many individual parts, some of them moving parts, and is therefore expensive, especially for a onetime use. Furthermore, the problems associated with the handling of the sample and the extract have not been solved. The filling of the extractor on the one hand and the transfer of the extracted sample material from the extractor to the centrifuge represent further problems. In this way, a not inconsiderable loss of sample material can occur, along with a risk of contamination during the transfer from one section of the apparatus to the next.
In summary, it can be said that the performance of the extraction due to the aforesaid reasons is at present cost-intensive, time-consuming, and involves a heightened risk of contamination for personnel and surroundings.
The extraction and preparation of a sample in chip format, i.e., in microfluidic amounts, by means of a module which can be directly connected to a microfluidic chip or a microfluidic arrangement is not known at present.
From WO 2006/029387 A1 is known a portable extraction device with a syringe-like arrangement for pipetting and dispensing an analyte, preferably a nucleic acid, to a purification chip. Between the syringe arrangement and the purification chip, a valve to guide the fluid flow and a filter arrangement are hooked up.
From DE 44 32 654 A1 is known a filtration arrangement for preparation of nucleic acids from natural sources with a syringe-like arrangement, by which the disintegration from the nucleic acid is furthered by a filtration arrangement located upstream from the outlet of the syringe arrangement.
A mere miniaturization of known filtration methods, however, would involve further problems. Traditional filter arrangements for sample extraction have the drawback that the filter pores very quickly get clogged, which necessarily places a limit on miniaturization. A large pressure difference during the filtration would moreover lead to a very fast transport of the extract in a connected microfluidic chip, which would jeopardize the fluidic control there. Also, the pressure strength of the usual microfluidic chips would not be able to withstand the pressures occurring during filtration.
The goal of the invention is to overcome the above problems.
SUMMARY OF THE INVENTION
This problem is solved with a microfluidic arrangement for extracting and optionally processing an extract from a sample and for transferring the extract in flowable form to a microfluidic chip with an extractor comprising a compressible extraction chamber and at least one opening thereof, a reactor that comprises a reaction chamber, an inlet opening that communicates with the at least one opening of the extractor, wherein the two openings define a flow path between the chambers, an outlet opening for fluidically connecting to the microfluidic chip and a ventilation opening of the reaction chamber, and a filter arrangement installed in the flow path between the extractor and the reactor. Advantageous modifications of the invention are the subject of the subclaims.
According to the invention, the microfluidic arrangement has an extractor, a reactor communicating with the extractor by a flow path, and a filter arrangement inserted in the flow path between the extractor and the reactor. The extractor, for its part, has a compressible extraction chamber and at least one opening in same. The reactor has a reaction chamber, an inlet opening communicating with the at least one opening of the extractor, while the two openings define a flow path between the chambers, an outlet opening to the fluidic connection with the microfluidic chip, and a ventilation opening of the reaction chamber.
The benefit of the microfluidic arrangement according to the invention is that a small number of components realize the full functionality of an extraction device in combination with a reaction chamber. The extraction occurs in the extraction chamber, in which the sample has previously been placed, along with the extraction buffer. By compressing the extraction chamber volume, the fluid portion of the extract is pressed by virtue of a pressure difference through the filter arrangement. Undissolved solids are held back in the filter arrangement. The liquid phase passes through the filter arrangement and gets into the reaction chamber.
Moreover, it is important to the invention that the reaction chamber is kept at nearly constant pressure by means of the ventilation opening, which creates a connection between the reaction chamber and the surroundings, whereas the pressure rises in the extraction chamber during the compression. This constantly ensures a sufficient pressure difference between the chambers, which prevents a clogging of the filter if the filter arrangement is adequately dimensioned. Moreover, the pressure from the extraction chamber is not introduced via the reaction chamber and its outlet opening into the microfluidic channel system of the chip and therefore does not lead to an uncontrolled flow behavior, especially an undesired outflow of the extract from the outlet opening, preferably situated at the bottom, from the reactor into the chip. Control of the flow in the chip occurs in customary manner by a pressure difference applied elsewhere on the chip (such as by means of pump or syringe) and a suitable valve control. Also, a control by capillary forces is possible in addition or alternatively to the mentioned version based on the decoupling between pressure in the extractor and microfluidic chip.
Preferably, the extractor has a cylinder-piston arrangement which encloses the compressible extraction chamber.
The realization of the compressible extraction chamber by a cylinder-piston arrangement is especially easy in technical respect. Both the cylinder and the piston can be made cheaply from a suitable polymer material by injection molding, hot stamping, or reaction molding.
One embodiment of the cylinder-piston arrangement calls for having the reaction chamber and the extraction chamber configured as continuous, preferably cylindrical cavity or consecutively arranged, preferably cylindrical cavities of the same or different diameter. The filter arrangement in the manner of a partition wall functionally divides the cavity or cavities into the extraction and reaction chambers. A piston, similar to a syringe, is inserted into the cavity of the extraction chamber in order to produce the necessary filtration pressure. The reaction chamber and possibly also the extraction chamber in this embodiment can be flanged as a separate, hollow cylindrical component onto a microfluidic chip or be integrated in it by forming the cavity in a thicker region of the chip. In particular, chip and reactor and possibly extractor will then be formed as a single piece.
Alternatively, the reactor can also be configured as an independent, preferably cylindrical insert or capsule, which is fitted fluid-tight into a segment of the preferably cylindrical cavity. The rest of the cavity forms the extraction chamber. The filter arrangement is formed by the wall segment of the insert or is integrated into this, which borders on the extraction chamber.
For obvious manufacturing technology reasons, the cavities forming the chambers or cylinders and the outer contours forming the piston in the aforementioned embodiments preferably have a cylindrical geometry.
Advantageously, the cylinder of the extractor can move relative to the filter arrangement and the reactor, while the filter arrangement and/or the reactor are at least partly coordinated with the piston or form the latter.
This can be especially well realized if the reactor is configured in the shape of a hollow cylinder, whose outer circumference is at least for one axial segment fitted into the bore of the extractor cylinder. On the inside of the reactor cylinder is formed the reaction chamber, which is spatially bounded off at the end face by the filter arrangement from the extraction chamber, but is not closed fluid-tight. A microfluidic arrangement of this kind can be produced at especially low cost and is therefore especially suited as a disposable device.
The filter arrangement preferably has at least one filter element and a filter holder connected to the reactor and pressing the filter element against the inlet opening of the reactor. The filter holder is firmly connected to the reactor cylinder by form fitting, frictional fitting and/or material connection, for example, by laser welding, gluing or press-fitting. To stabilize the filter element, a filter bracket can be arranged in front of the entry opening of the reactor. If it is also ensured in this way that the filter element rests fluid-tight against the filter holder or is connected to it, one furthermore ensures that the extract on the way to the reaction chamber must pass through the filter element, so that no unwanted particles can get into the reaction chamber.
In order to make the cylinder-piston arrangement in this embodiment fluid-tight to the outside world in easy manner, the filter holder preferably also has a cylindrical outer contour. With corresponding accuracy of fit, the filter holder can be press-fitted into the hollow cylinder of the extractor. Alternatively, a sealing element is arranged between one outer wall of the filter holder and one inner wall of the extractor cylinder. The sealing element can be fashioned as a one-piece sealing lip, given sufficient elasticity of the material of the filter holder, or as a separate sealing ring.
According to one advantageous modification, the extractor has a stirring element enclosed in the extraction chamber.
This can be, e.g., a magnetic stirring rod (also known as a stir bar) or some other stirring element that is operated without contact. Alternatively or additionally, a mixing effect can also be achieved by acoustic means, vibration or convection through heating or cooling, or by a combination of these measures.
The reactor in the form of a hollow cylinder preferably has a flange for fastening to a microfluidic chip.
The lab-on-a-chip system has a microfluidic arrangement of the above described kind with an extractor, a reactor and a filter arrangement and a microfluidic chip firmly connected to the reactor.
By “firmly connected” is meant here, in contrast to the prior art (e.g., a hose connection), a direct physically neighboring arrangement, possibly with a seal in between. The reactor is, for example, flanged to the aforementioned flange, preferably by means of suitable fastening means (such as screws or clamp elements) by form fitting or by material connection (gluing, welding, especially ultrasound welding) directly to the microfluidic chip.
In the integrated lab-on-a-chip system according to the invention, all of the process steps of a chemical or biochemical assay can be imitated, from the preparation of the sample to the extraction or the detection of the analyte, avoiding the numerous costly and often error-prone individual steps that are necessary in laboratory operation. Examples of assays are enzyme linked immunosorbent assays (ELISA) and polymerase chain reaction (PCR).
At least one channel is provided in the microfluidic chip, communicating with the outlet opening of the reactor.
In one advantageous modification, the microfluidic chip has a valve arrangement for optional connecting or separating of the channel(s) communicating with the outlet opening of the reactor with at least one inlet and/or outlet line.
This makes it possible, for example, to introduce one or more different reagents and/or gases in succession or at the same time through the inlet line(s) in the chip into the reaction chamber and/or remove extract through the outlet line(s) in the chip from the reaction chamber for further processing or investigation. Nor can excess pressure or partial vacuum be formed in the reaction chamber by the ventilation opening. A special application is the introducing of air in the reaction chamber for purposes of mixing of the liquid in the reaction through air bubbles. For this purpose, as well as for safe emptying of the reaction chamber, its outlet opening is situated at the lowest point of the reaction chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
Further problems, features and benefits of the invention shall be explained more closely below by means of a sample embodiment with the help of the drawings. There are shown:
FIG. 1 a perspective representation of one embodiment of the lab-on-a-chip system according to the invention;
FIG. 2 a sectional view of the lab-on-a-chip system according to FIG. 1 ;
FIG. 3A a sectional side view to illustrate one applications of the lab-on-a-chip system according to the invention and
FIG. 3B a top view of the system layout according to FIG. 3A .
DETAILED DESCRIPTION OF THE INVENTION
In FIGS. 1 and 2 , the lab-on-a-chip system 10 according to the invention is illustrated by means of one embodiment with a microfluidic chip 12 and a microfluidic arrangement 14 for the extracting and possibly processing of an extract from a sample and for transfer of same in flowable form to the microfluidic chip 12 . The microfluidic chip has a valve arrangement 16 , which optionally connects one or more inlet and/or outlet lines 18 to a channel 20 or separates them from it. For example, suitable valve arrangements are described in the currently not yet published patent applications DE 10 2008 002 674.3 or DE 10 2008 002 675.1. These have a valve body which can move relative to the chip, which has a sealing surface and defines at least one channel for optional connection and/or separation of fluid lines in the substrate, while the sealing surface of the valve body lies fluid-tight against a sealing surface of the chip. For this, the valve body is pressed against the chip by means of a pressing ring materially connected to the substrate or by means of a clamping element form-fitted to the substrate, while the pressing ring and the clamping element and/or the valve body is at least partly elastic.
The channel 20 emerges into a funnel-like expansion that is open at the top (or drain funnel) 22 in the microfluidic chip 12 . The chip 12 , in familiar manner, consists of a suitable polymer material and has an essentially rectangular, flat shape similar to a chip card. Suitable plastics are thermoplastics and duroplastics, such as acrylonitrile-butadiene-styrene copolymerizate (ABS), polyoxymethylene (POM), polyether ketones (PEEK), polymethylmethacrylate (PMMA), cyclo-olefin copolymers (COC), cyclical olefin polymers (COP), polycarbonate (PC). The chip 12 is typically a few millimeters thick, while the channel structures are worked into the substrate from the top or bottom side and are sealed by a thin film on the top or bottom side.
On the top side 24 of the chip 12 is found the microfluidic arrangement 14 . This has an extractor 30 , a reactor 32 and a filter arrangement 34 . The extractor 30 has a cylinder-piston arrangement, with parts of the filter arrangement 34 and the reactor 32 forming the piston. The cylinder 36 , coordinated with the extractor 30 , has a cylinder shell 38 and a cylinder cover 40 , which is joined by screws 42 firmly to the cylinder shell 38 and sealed off by a seal 44 . The cylinder 36 encloses, at the side opposite the cylinder cover 40 , bounded by the piston and more precisely by the filter arrangement 34 , a volume, namely, the extraction chamber 46 . In the extraction chamber, through the initially opened cylinder cover 40 , is placed the sample and an extraction buffer, and the cover 40 is then closed once more. For an easier handling, instead of the cover fixed by the screws 42 , a screw-on cover, a snap or click closure, or a glue surface can be used.
In the extraction chamber 46 , moreover, there is a stirring element 48 in the form of a magnetic stirring rod for mixing the sample with the extraction buffer. The extraction cylinder 36 can be closed in axial direction relative to the piston, i.e., relative to the filter arrangement 34 and the reactor 32 . In this way, the extraction volume 46 can be compressed by pressure from above on the extraction cylinder 36 .
The filter arrangement 34 consists basically of one or more filter elements 50 , a filter holder 52 and a filter bracket 54 . The filter holder has a cylindrical outer contour, in which an annular groove 56 is made to receive a sealing ring. This sealing ring seals off the extraction chamber 46 from the outer world, so that no liquid can escape between the extractor cylinder 36 and the piston.
The reactor 32 consists basically of a hollow cylindrical shell (in short, hollow cylinder) 58 with a one-piece flange 60 arranged at one end. The hollow cylinder 58 has a continuous bore, which forms the reaction chamber 62 with an inlet opening at its top side and an outlet opening at its bottom side. On the bottom side of the flange 60 and correspondingly on the top side 24 of the chip 12 there is an annular groove 64 of the same diameter to receive a sealing ring. Alternatively, the annular groove can be made either only in the flange or only in the chip. The flange 60 if firmly connected to the chip 12 by means of a screw connection 66 and sealed off by means of the sealing ring, so that no liquid can escape from the reaction chamber 62 at this site into the surroundings.
The outlet opening of the reaction chamber 62 is oriented to the funnel-like expansion 22 in the microfluidic chip 12 and thus stands in fluid communication with the channel 20 of the microfluidic chip 12 . The upper, open end of the funnel-like expansion 22 has a somewhat larger diameter than the continuous bore of the reaction chamber 62 . This ensures that, after the reaction chamber 62 is emptied, no liquid remains behind in dead spaces or corners at the transition from the extractor 32 to the chip 12 .
In the reaction chamber 62 , moreover, there is a capillary tube 68 arranged eccentrically to the continuous bore. The capillary tube 68 at its bottom side pierces the microfluidic chip 12 . It is open at top and bottom, so that it provides a ventilation opening, which connects the volume of the reaction chamber 62 to the surroundings. Optionally, a filter can be provided at one end and/or the other of the tube 68 , preventing an escape of germs into the surroundings or, on the contrary, a penetration of contaminants into the extract.
At the upper end face of the reactor cylinder 58 is the filter bracket 54 . This carries or supports the filter element(s) 50 . The filter holder 52 is fashioned as a sleeve and has an inner threading at its bottom side, which screws together with a corresponding out thread of the reactor cylinder 58 . In this way, the filter holder 52 by an inwardly directed ring-shaped edge pushes the filter elements 50 against the filter bracket 54 , which in turn is propped against the reactor cylinder 58 . In this way, a fluid-tight contact is formed between the ring-shaped edge of the filter holder 52 and the filter element, ensuring that the extract when the extractor cylinder is pressed down can only get through the filter element into the reaction chamber 62 , so that no unwanted solids can get past the filter element and into the chamber.
The filter bracket 54 has, at its bottom side in the center, a drip spout 70 , where the extract forced through the filter element(s) 50 at first collects before it drips into the reaction chamber 52 . This prevents the extract from getting by an undefined path into the extraction chamber 62 . In particular, it prevents the extract from closing the ventilation opening of the capillary tube 68 .
In the present embodiment, a total of three filter elements 50 are installed. These are specifically uppermost and lowermost a stainless steel filter with a pore size of 200 μm and in between a filter of polyamide with a pore size of 20 μm. The graduating of the pore size of the filter from the larger to the smaller cross section means that in the first filter only the largest particles are held back and sufficiently large continuous openings are formed for smaller particles, which then get caught at the next filter stage. A fouling is largely prevented in this way. The third filter element with, again, larger pore size serves to support the middle, finer filter element. Alternatively or additionally, a filter additive in the form of particles can be used, which like the first coarse filter forms a matrix passable by fine particles and prevents a fouling.
This system enables filtration of samples at high pressures of up to 10 bar. Very good filtration results can be achieved in this way, without the filter element getting clogged. On the other hand, the ventilation makes sure that the fluidic control in the channel system of the microfluidic chip 12 is not lost, despite high pressure.
In a lower axial segment, the reactor tube 58 has a heating cuff 72 arranged on its circumference. This can be used when needed to transform the extract, for example, in a chemical and/or thermal lysis or for acceleration by heating the extract.
Instead of the embodiment shown with flange, chip and reactor can also be fashioned as a single piece. Instead of the screwing of the flange, the connection can also be form fitting by a kind of “quick closure” (click connection) or a material connection (welding or glue connection).
Instead of the orientation shown in the figures, the device can also be intended and designed for overhead operation. In this case, the extractor cylinder can have a solid bottom and be filled from the side of its (single) opening and then be placed onto the reactor cylinder in this orientation from the bottom. The overhead operation under some circumstances already brings about a sedimentation, that is, a separation of the heaviest, largest particles onto the bottom surface of the extractor cylinder. In this way, the filter process can be supported, depending on the application, for example, by a separating of the sample components in the case of soil samples.
In FIGS. 3A and 3B , a representation of the invented lab-on-a-chip system 10 is shown to illustrate the mode of functioning, especially the introducing of substances into the reaction chamber. As is best seen in the sectional side view of FIG. 3A , the microfluidic arrangement 14 of the invention is situated on the top side of the chip 12 . At its bottom side, the housing of the valve arrangement 16 is flanged on. The valve arrangement contains a rotary valve, with a valve body that has at least one channel which can be displaced relative to the chip by rotation for the optional connecting of at least two fluid channels in the chip. In all, 6 inlet and outlet lines 18 and the channel 20 are connected to the rotary valve 16 , as can be seen in the top view of FIG. 3B . The inlet and outlet lines 18 a , 18 b , 18 c and 18 d within the chip 12 each consist of a channel, which is identical in structure to the channel 20 , and outside the chip they consist of a connection piece, in this case, a segment of hose. The other two inlet and outlet lines 18 have no external connection piece. Optionally, by rotating the valve (manually or automatically), the channel 20 can be connected to the end of at least one inlet or outlet line 18 .
The chip design and the valve functionality are indicated here only as examples. It is at the discretion of the practitioner to design the valve arrangement for the particular requirement.
As an example, a syringe or pump 74 and 76 respectively are connected to the inlet lines 18 a and 18 b , more precisely, to the free ends of their hose segments. The syringe 74 in the example shown is filled with air or some other gas. The syringe 76 can be filled with a suitable reagent; for example, in the immunoassay, an antibody bead solution, or in the DNA assay a reagent for the chemical and/or thermal lysis and/or bonding additives. To perform an immunoassay, we first operate the valve in the valve arrangement 16 so that a connection is produced between the inlet line 18 b and the channel and, thus, between the syringe 76 and the reaction chamber 62 . The solution found in the syringe 76 is injected. After this, the valve arrangement 16 is adjusted so that the gas-filled syringe is connected to the reaction chamber 62 . Now, the syringe 74 is activated, so that the gas contained therein is taken through the inlet line 18 a and the channel 20 to the reaction chamber 62 . At first, the residual solution is emptied from the channel 20 into the reaction chamber 62 . Next, the gas emerges there in the form of bubbles 78 from the mouth of the channel 20 . The bubbles 78 rise in the extracted liquid in the reaction chamber 62 and serve in particular for the mixing of same; thus, in this example, the mixing of the filtrate with the antibody bead solution.
When the lysis or labeling in the reaction chamber 62 is concluded, the valve arrangement is adjusted so that the end of the channel 20 is connected to the start of another outlet line 18 , 18 c , 18 d . The mixture in the reaction chamber 62 can be taken via the microfluidic path so formed through the microfluidic chip 12 , for example, to a connected concentrating and detection module (not shown) or one that is also located on the chip.
The above-described ventilation of the reaction chamber 62 always ensures a controlled fluid transport with very slight pressure differences in the entire process. An experiment has shown that it is possible, thanks to the ventilation capillary, to organize the liquid transport from the reaction chamber to the chip so robustly that no further process control is necessary, such as sensors for detection of the liquid level in the fluid channels at the exit of the extractor.
For explanation of the patent claims, it should be noted that the terms inlet line, outlet line, reactor, extractor, valve arrangement or filter arrangement are to be understood as primarily functional. Structurally, the housing segment forming the reactor and the valve arrangement can be at the same time part of the extractor, namely, the piston, as shown by the sample embodiment. The inlet and outlet lines at least within the chip do not differ structurally from the channel. Functionally, however, they form a connection between the valve and a periphery, while the channel describes the connection segment between the valve and the reaction chamber.
LIST OF REFERENCE NUMBERS
10 Lab-on-a-chip system
12 Microfluidic chip
14 Microfluidic arrangements
16 Valve arrangement
18 , 18 a , 18 b , 18 c , 18 d Inlet and/or outlet lines
20 Channel
22 Drain funnel
24 Top side
30 Extractor
32 Reactor
34 Filter arrangement
36 Cylinder
38 Cylinder shell
40 Cylinder cover
42 Screws
44 Seal
46 Extraction chamber
48 Stirring element
50 Filter element
52 Filter holder
54 Filter bracket
56 Annular groove
58 Hollow cylinder
60 Flange
62 Reaction chamber
64 Annular groove
66 Screw connection
68 Capillary tube
70 Drip spout
72 Heating cuff
74 Syringe
76 Syringe
78 Bubble | A microfluidic arrangement for extracting and optionally processing an extract from a sample and for transferring the extract in flowable form to a microfluidic chip using an extractor with a compressible extraction chamber and at least one opening thereof, a reactor that has a reaction chamber, an inlet opening that communicates with the at least one opening of the extractor, wherein the two openings define a flow path between the chambers, an outlet opening for fluidically connecting to the microfluidic chip and a ventilation opening of the reaction chamber, and having a filter arrangement installed in the flow path between the extractor and the reactor. A lab-on-a-chip system with such a microfluidic arrangement and a microfluidic chip that is rigidly connected to the reactor. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to lighting devices such as flashlights and lanterns.
BACKGROUND OF THE INVENTION
[0002] The flashlights and lanterns disclosed in PCT/AU00/00720 the lighting devices contained therein require improvements thereto to extend the uses of such lighting devices.
[0003] In regards to the prior art discussed herein, the applicant does not concede that that prior art forms part of the common general knowledge in the art in Australia or elsewhere, at the priority date of this application.
SUMMARY OF THE INVENTION
[0004] The present invention provides a lighting device having a light housing including a light source being rotatably connected by a rotatable connection means to a lighting device body, said body having said rotatable connection means positioned so as to allow said light housing to lay adjacent said body and to define therebetween a narrow space which is accessible in a base to top direction.
[0005] The body is preferably dimensioned so that the depth of said body is less than the height or width. The height and width are selected so as to be capable of fitting into a pocket on an article of clothing. Preferably said height is in the range of 4 cm to 14 cm. Preferably the width is in the range of 4 cm to 14 cm and preferably the depth is in the range of 1 cm to 4 cm. The body can include a fold out foot. The fold out foot can also include formations thereon to allow said lighting device to be hung. Preferably means are provided to releasably hold said light source adjacent to said lighting device body. In a preferred embodiment said means to releasably hold said light source adjacent to said lighting device body comprise one or more protrusions which act as a camming means to provide a bias which must be overcome in order to rotate said light source from a position adjacent to said lighting device body.
[0006] The present invention also provides a lighting device having a light source assembly with a light source and a tubular lens surrounding said light source to provide an appearance similar to that of a fluorescent lamp when in use, said light source assembly being further characterised by the provision of a reflector co-operating with an end of said tubular lens opposite to said light source.
[0007] Preferably said light source is an LED or incandescent lamp.
[0008] Preferably said reflector is located within said tubular lens.
[0009] The reflector can be located on the end of a spigot. The spigot can be used to mount or position said tubular lens in said lighting device.
[0010] The reflector can be concave or convex. Preferably said reflector is dome shaped. Preferably said reflector and said cylindrical member are manufactured from the same material. The reflector and spigot can be integrally formed or alternatively joined together.
[0011] Preferably said reflector and spigot are formed from white polymeric material. Preferably said spigot is of a cylindrical shape.
[0012] The present invention further provides a light housing for a lighting device, said light housing including a first and second face and sides there around, a first side having a mounting spigot to receive one end of a tubular lens, and a second side opposite to said first side having an aperture therethrough, through which aperture tubular lens can pass and in which is received the other end of said tubular lens, said aperture and said mounting spigot being aligned.
[0013] Preferably an internal face of one of said first or second faces includes a channel extending from said aperture to said spigot. Preferably the spigot is located in said first side so that when the tubular lens is mounted thereon, opposing locations on said tubular lens in the vicinity of said spigot are in contact with respective internal surfaces of said first and second face.
[0014] Said first face can be one of the following:
[0015] opaque and reflective on an internal face; transparent; translucent.
[0016] The second face can be one or more of the following:
[0017] transparent; translucent; or opaque and reflective on an internal face when said first face is transparent or translucent.
[0018] Preferably said tubular lens is held in said light housing by a light source projecting through said aperture.
[0019] The light source can pass into said tubular lens.
[0020] The light source can be an LED or an incandescent lamp. Said light housing can include an open box with said first face and said sides, said second face being a cover which is attached to said box. Preferably said box is made from a white opaque reflective material and said cover is transparent.
[0021] The invention further provides a method of assembling a light housing as described above, said method including the steps of:
[0022] Attaching said cover to said box;
[0023] inserting said tubular lens through said aperture;
[0024] engaging said spigot with one end of said tubular lens;
[0025] inserting said lighting source into the second end of said tubular lens; and
[0026] securing said light source to said housing.
[0027] The spigot can be attached to said cover or to said box.
[0028] The present invention also provides a method of assembling a light housing as described above, said method including the steps of:
[0029] locating said light source through said aperture and attaching same to said housing;
[0030] connecting one end of said tubular lens to said spigot on said cover;
[0031] guiding the free end of said tubular lens onto said light source;
[0032] rotating said cover around said light source until said cover engages said box;
[0033] securing said cover to said box.
[0034] The present invention further provides a light housing for a lighting device, said light housing including a light source holder at one end thereof, said light housing also including means to receive a mounting member at one end of said light housing opposite to said light source holder, said light housing being characterised by said light source holder allowing limited pivotal movement of said light source when said light source is mounted in said light source holder, said limited pivotal movement being in the range of 5° to 30°. This pivotal movement allows the light source to be oriented at an angle so that the lens assembly can be mounted thereon and rotated in position into the light housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] An embodiment of the present invention, will now be described, by way of example only, with reference to the accompanying drawings in which:
[0036] [0036]FIG. 1 is a front perspective view of a lighting device with all features fully extended;
[0037] [0037]FIG. 2 is a rear view of the apparatus of FIG. 1;
[0038] [0038]FIG. 3 is a front perspective view of the apparatus of FIG. 1 with its light housing in the retracted position;
[0039] [0039]FIG. 4 illustrates a front perspective view of the lighting device of FIG. 3 with the foot retracted;
[0040] [0040]FIG. 5 illustrates a rear perspective view of the lighting device of FIG. 4;
[0041] [0041]FIG. 6 illustrates a cross-section through the middle of the lighting device of FIG. 4;
[0042] [0042]FIG. 7 illustrates a plan view of the light housing and some internal portions thereof;
[0043] [0043]FIG. 7A illustrates a front view of a printed circuit board;
[0044] [0044]FIG. 8 illustrates the cover of the light housing in plan view;
[0045] [0045]FIG. 9 illustrates a side view of the cover of FIG. 8;
[0046] [0046]FIG. 10 illustrates the spigot;
[0047] [0047]FIG. 11 illustrates the spigot in cross section; and
[0048] [0048]FIG. 12 illustrates a perspective view of a light box.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0049] Illustrated in FIGS. 1 and 2 is a lighting device 2 which has a body 4 and a light housing 6 . The base of the body 4 has a foot 8 that is rotatably attached to the body 4 . The foot 8 is illustrated in the extended position.
[0050] The body 4 includes a rear face 20 having a cover 10 the removal of which gains access to the battery or dry cell compartment and a switch 12 to switch on the light source assemblies 14 and 16 either both at the same time or one thereof
[0051] The body 4 is of a generally rectangular construction having a light housing mounting 18 which is offset in a rearward direction from the rear face 20 . The light housing mounting 18 has rotatably attached to it the base 22 of the light housing 6 . The base 22 of the light housing 6 additionally includes two raised projections 23 which act as a camming means to releasably hold the light housing in a closed position against said body as will be described below.
[0052] The body 4 is in the main of a generally rectangular prism shape where the height and width are dimensioned so as to be capable of fitting into a pocket on an article of clothing such as a top pocket of a shirt or jacket, pants or other clothing articles. To effect this the height is approximately 100 mm and the width is approximately 60 mm, and the depth is approximately 20 mm. Whilst these are the selected dimensions of the preferred embodiment the height could vary between 40 mm and 140 mm; the width could vary between 40 mm and 140 mm; and the depth can vary between 10 mm and 30 mm depending on pocket size.
[0053] The foot 8 is pivoted at the forward most lower most edge 24 on the body 4 . As can be seen from FIG. 1 the foot 8 includes a key hole shaped slot 26 which allows the foot 8 to be attached to overhead rope or a tent rope etc to position the light for use by a user. Adjacent the slot 26 is a hole 28 which will allow the hanging of the light on a thin string or a twig or a nail of the like.
[0054] As can be seen in FIGS. 1 to 4 the light housing 6 is able to be rotated from a fully retracted position such as that of FIGS. 3 to 5 to a fully extended position by travelling through an arc of greater than 180° to approximately 225° from its fully retracted position.
[0055] The two raised projections 23 act as a camming means to provide a locking bias to releasably hold the light housing in the retracted position.
[0056] The raised projections 23 are positioned on the base 22 of the light housing 6 such that when the light housing 6 is in a retracted position, as shown in FIGS. 3 and 4 the raised projections 23 are rotated beyond the crest of a curved edge 21 in the upper housing wall, between the light housing mountings 18 . In order to rotate the light housing 6 relative to the body 4 the raised projections 23 must be urged past a curved edge in the upper housing wall 21 between the light housing mountings 18 . In the retracted position the projections 23 rest against the upper housing wall 21 and exert a force against the upper housing wall 21 which holds the light housing 6 in the retracted position. Thus the force exerted by the raised projections 23 against the curved upper housing wall 21 provides a resistance against rotation of the light housing and releasably holds the light housing 6 in a retracted position.
[0057] The light device 2 differs from the one disclosed in PCT/AU00/00720 in that the light housing 6 if preferably contained within a light box 30 as illustrated in FIG. 12 having an opaque rear face 32 and a clear forward cover 34 . The forward rear and rear locations refer to the light housing 6 when it is in the fully extended position. As can be seen from FIG. 5 the front cover 34 is rearwardly facing in the fully retracted position. The light box 30 as illustrated in FIG. 12 includes two shallow, curved in cross section, channels 33 in which can sit tubular lenses 48 and 50 .
[0058] As illustrated in FIG. 6 in cross section, the fully retracted lighting device 2 has four AA sized batteries 36 contained in the battery housing 38 which is closed by the cover 10 when secured in place by the latch 40 .
[0059] Preferably the rear face 32 of the light box 30 does not allow light to be transmitted therethrough, but acts as a reflector to assist in projecting light through the forward cover 34 . In order to achieve this end one or more of the surfaces of the rear face 32 can either be coated in a reflective material, or have a reflective element, such as a reflective adhesive film or metallic reflector attached thereto. Alternatively, the rear face 32 can be formed of an opaque reflective material, such as a white plastics material. Furthermore the surface of the rear face 32 , which is closest to the tubular lenses 48 , 50 can be textured to provide a diffuse reflection, or polished to provide a specular reflection.
[0060] As can be seen from FIGS. 1 to 6 the light housing 6 is made from light box 30 and holds the two light source assemblies 14 and 16 . The light sources assemblies 14 and 16 are comprised of LEDs 42 and 44 respectively, translucent tubular lenses 48 and 50 respectively and securing spigots 52 and 54 respectively. As illustrated in FIG. 7 the LEDs 42 and 44 are mounted on a printed circuit board 46 . The printed circuit board 46 is illustrated in more detail in FIG. 7A.
[0061] Each securing spigot 52 and 54 includes a domed end 56 which is a reflector of light emitted from the LEDs 42 and 44 . The spigots 54 and 52 are illustrated in more detail in FIG. 10. The spigots 54 and 52 have a peg 58 extending away from the dome 56 and a generally cylindrical body 60 . The outside diameter of the cylindrical body 60 is sized so that the spigots 52 and 54 can slide into the internal diameter of the tubular lenses 48 and 50 . In turn the tubular lenses 48 and 50 are sized so as to receive within their internal diameter the respective LEDs 42 and 44 .
[0062] As can be seen in FIGS. 7 and 12 the light box 30 has two apertures 63 and 62 which allow for the assembly of the lights source assemblies 14 and 16 within the light box 30 . This will be described in more detail below.
[0063] Illustrated in FIGS. 8 and 9 the cover 34 has two flanges 64 which each have an aperture 66 therethrough. The flanges 64 also have a curved projection 65 , which will sit in the channel 33 when the cover 34 is attached to light box 30 . The aperture 66 receives the peg 58 on each of spigots 52 and 54 so as to mount the spigots 52 and 54 on the cover as illustrated in FIG. 7.
[0064] For this embodiment to assemble the light housing 6 , the pivoting base 22 (which is made up of rear half 68 and front half 70 ), and the light box 30 are assembled together with the printed circuit board 46 and LEDs 42 and 44 . To do this assembly spigots (not illustrated) on front half 70 are received in apertures 72 on light box mounting 74 to form an interim sub assembly. The printed circuit board 46 and soldered LEDs 42 and 44 are connected by wires to the body 4 which wires pass through stub axles 76 on the light housing mounting 18 . The printed circuit board 46 is then positioned so that the LEDs 42 and 44 protrude into the apertures 62 and 60 respectively. The printed circuit board 46 is prevented from moving on the front half 70 by means of a series of ribs or projections (not illustrated). The front half 70 and clipped in light box 30 with the printed circuit board 46 are then mated with the rear half 68 around the stub axle 76 (there are two of these hollow stub axles or cantilevered pivots 76 but only one is visible) so as to sandwich the axle 76 between the halves 70 and 68 which in turn are sandwiching the end of the light box 30 at the other end of halves 70 and 68 . The halves 70 and 68 are then secured by four screws 78 and 80 . The screws 80 pass into the spigots on front half 70 which pass through the aperture 72 on light box mounting 74 . During this sub assembly the cover 34 is not in position.
[0065] Next the spigots 52 and 54 are mounted onto the cover 34 by insertion into apertures 66 in flanges 64 .
[0066] The mounting of the printed circuit board 46 between the halves 68 and 70 is such that the printed circuit board 46 is allowed a small degree of rotation in the direction of arrow 80 . This small degree of rotation measuring approximately 5° to 30° allows the LEDs 42 and 44 to assume an elevation relative to the rear face 32 .
[0067] To assemble the light source assemblies 14 and 16 , the distal ends of the tubular lenses 48 and 50 are loosely mounted onto the cover 34 at one end by slipping the lenses 48 and 50 over the spigots 52 and 54 . Then the cover 34 is held at an angle whereby the proximal ends of the tubular lenses 48 and 50 receive at least a portion of the extremities of the LEDs 42 and 44 . The channels 33 assist in guiding the tubular lenses 48 and 50 to the LEDs 42 and 44 . The cover 34 is then moved towards the light box 32 so that four downwardly extending spigots 80 on cover 34 will be received in cylindrical mounts 82 on the light box 30 . As the cover 34 approaches the light box 30 pressure or force is applied to the cover 34 so as to sandwich the tubular lenses 48 and 50 between their respective LEDs 42 and 44 and spigots 52 and 54 .
[0068] The LED end of the tubular lenses 48 and 50 pass through a raised entry 84 on the light box 30 which prevents any lateral movement of the tubular lenses 48 or 50 when the light housing assembly 6 is completed. Any axial movement of the tubular lenses 48 and 50 is prevented by the LEDs 42 and 44 (and spigots 52 and 54 ) which have a flanged end as is common with LEDs. Once the respective spigots 80 and cylindrical mounts 84 are aligned, the cover 34 is simply clipped into place with flexible spigots 86 being pushed towards the centre of the cover 34 until they are aligned with an aperture 88 in the light box 30 , where upon the spigots 86 will proceed into aperture 88 to thus lock the cover 34 in position on the light box. Once this happens the tubular lenses 48 and 50 are located in the channels 33 . The two longitudinal edges of the channels 33 will thus keep the tubular lenses straight when the light housing 6 is assembled and in use.
[0069] In an alternative method of assembly the cover 34 can be pre-subassembled to the light box 30 . In this assembly method, the cover 34 will first have attached to it the spigots 52 and 54 . Once this sub-assembly is completed the tubular lenses 48 and 50 can be passed through the apertures 62 and 64 and guided by channels 33 so that the distal end of the tubular lenses 48 and 50 will be placed over the spigots 52 and 54 with the proximal end of the tubular lenses 48 and 50 protruding through the raised entries 84 .
[0070] The next stage in the assembly of the light housing 6 is to mount the light box 30 by means of apertures 72 on light box mounting 74 onto the front half 70 of the light housing base 22 to form an interim sub assembly. At this point the printed circuit board 46 and the two LEDs 42 and 44 can then be positioned into the proximal ends of the tubular lens 48 and 50 thus securing the two tubular lenses 48 and 50 in position. The printed circuit board 46 is then held in the light housing by the rear half 68 of the base 22 being attached while simultaneously capturing the hollow stub axles 76 . The power supply leads for the LEDs 42 and 44 pass through the hollow stub axles 76 .
[0071] With this alternative method if desired, the spigots 52 and 54 need not be mounted to the cover 34 per se but rather could be attached or received by the wall 31 of the light box 30 opposite to the wall 37 containing apertures 62 and 64 . In which case the assembly procedure will continue as described in the alternative assembly method.
[0072] A lighting device 2 such as that described above provides a space 90 between the rear panel 32 and the cover 10 when the foot 8 is in the retracted position as illustrated in the cross section of FIG. 6.
[0073] The space 90 between cover 10 and rear panel 32 can be widened by rotating these two components relative to each other to a small extent, say 5° to 10°. Because of the retraction of the foot 8 , access to the space 90 is clear and unobstructed thus allowing the body 4 to be placed in a pocket with the material of the pocket lying inside the space 90 . Additionally the body 4 can be held by a user's belt; pant's elastic; draw cord; string or chain around a person's neck, to the person with the light housing 6 rotated to a position whereby it is ready for use.
[0074] The pivotal connection between the light housing 6 and body 4 can be provided with a degree of friction or resistance to movement. This friction or resistance can assist the lighting device 2 to sandwich a pocket wall in an effective manner. Gravity will keep the lighting device on the pocket wall providing the direction of opening or entry to the pocket will allow gravity to act in a positive manner. Otherwise the degree of friction or resistance to rotation the light housing will assist in positioning the light 2 to allow use of the light 2 . In a particularly advantageous embodiment a locking mechanism, such as the camming action of the raised protrusions 23 as described above, can be used to providing a small clamping force to hold the lighting device 2 in place whilst hung on a pocket or the like.
[0075] If desired the light 2 can be hung from the neck line of an article of clothing so as to centre the light and allow reading therewith in low light situations such as when travelling, camping purposes, aeroplanes and the like.
[0076] It will be 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 or drawings. All of these different combinations constitute various alternative aspects of the invention.
[0077] The foregoing describes embodiments of the present invention and modifications, obvious to those skilled in the art can be made thereto, without departing from the scope of the present invention. | 1. A lighting device ( 2 ) having a light housing ( 6 ) including a light source ( 42, 44 ), said light housing rotatably connected to a body, said body having a rotatable connection means ( 22 ) to allow the light housing to be adjacent said body to define a narrow space ( 90 ) accessible in a base to top direction. 2. A lighting device ( 2 ) having a light source ( 42,44 ), a tubular lens ( 40, 50 ) surrounding said light source, a reflector ( 56 ) cooperating with an end of said tubular lens opposite to said light source. 3. A light housing ( 6 ) or a method of assembling a light housing ( 6 ), said light housing having a first side and a second side, a first side having a mounting spigot ( 52, 54 ), a second side having an aperture ( 62, 63 ), a tubular lens ( 48, 50 ) can pass through the aperture so that one end of the tubular lens is received in the mounting spigot, said aperture and said mounting spigot being in alignment. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a laminate film using a magnetic material and in particular to a magnetization-conduction interactive element, using the same, having magnetoresistance effect with high sensitivity.
2. Description of the Prior Art
Conventional magnetoresistive elements using a magnetic material include those constructed of a magnetic metal/nonmagnetic metal or laminate films, such as magnetic oxide/superconducting oxide/magnetic oxide, described in Japanese Patent Laid-Open No. 63249/1993.
A magnetoresistive element prepared by using the conventional laminate film exhibits a magnetoresistance effect as low as about 10% in a strong magnetic field of not less than 1000 Oe, or, even though the magnetoresistance effect could be attained in a magnetic filed of several Oe, exhibits a magnetoresistance effect as low as about 5%. Thus, the magnetoresistive element, when used as a magnetic sensor, creates only a small signal change, requiring a signal amplifier and signal calibration. Therefore, the construction becomes complicate, posing a problem that the cost involved in auxiliary devices is higher than that of the sensor per se. Further, since a switch utilizing magnetism is mechanically operated, there are problems associated with durability of a movable section, a large size of the movable section, limitation of the place where the switch may be installed. On the other hand, the perovskite type ferromagnetic material exhibits a large signal change. It, however, has a problem that somewhat large magnetic field is necessary. The present invention provides a simple magnetic sensor and a device material which can eliminate the need to provide any auxiliary device, such as an amplifier.
SUMMARY OF THE INVENTION
The present invention provides a magnetoresistive element comprising a combination of an electroconductive, crystalline magnetostrictive material or an amorphous magnetostrictive material with an electrically insulating layer and an oxide magnetoresistive material, or a combination of an electrically insulating oxide magnetostrictive material with an oxide magnetoresistive material.
The oxide magnetoresistive material is an oxide comprising a trivalent element, such as Mn and a rare earth element, as a main constituent element, which exhibits ferromagnetism upon deficit of a divalent element, such as an alkaline earth metal, a monovalent element, such as an alkali metal, or oxygen or a deviation from a stoichiometric ratio although it usually exhibits antiferromagnetism at the magnetic transition temperature or below. This material exhibits metal-like low electrical resistance in a ferromagnetic state at a temperature higher than the magnetic transition temperature. On the other hand, it exhibits semiconductor- or insulator-like high electrical resistance in a paramagnetic state at a magnetic transition temperature or above. In this magnetoresistive material, an electron of a main element, for example, Mn, is responsible for magnetization and conduction, and the magnetoresistance effect is created through a close relationship between the magnetization and the conduction. This effect has become studied as CMR effect from around 1994. Operation at room temperature, however, requires a magnetic field as high as several tens of T, and operation at a low magnetic field is necessary for utilization in a sensor or the like. This magnetoresistive material is an oxide which comprises, for example, manganese as a main constituent element, and the magnetic properties and electrical properties have a close relationship with the crystal structure. For example, when the rare earth element is changed, in other words, when the ion radius is changed, the magnetic transition temperature is also changed. This is attributable to a change in a main element responsible for conduction and a relationship between the main element (for example, manganese) and oxygen. Further, application of pressure results in a change in relative distance between main elements, leading to a change in magnetic transition temperature.
Thus, for the magnetization-conduction interactive element of the ferromagnetic oxide, the magnetization-conduction interaction is sensitive to external energy, that is, stimuli, such as electromagnetic wave, electric field, magnetic field, light, pressure, heat, and sound. When a current is allowed to flow during creation of the magnetization-conduction interaction, the electron responsible for the conduction and the electron of manganese cause the magnetization-conduction interaction. In this case, a change in interaction is detected as a change in electrical resistance. The oxide magnetoresistive material is an oxide having a perovskite structure DEMnO 3 or a layer perovskite structure DE 2n-1 Mn n O 2n+1 wherein DE represents at least one element selected from the group consisting of rare earth elements and alkaline earth elements and n represents an integer of one or more. Specific examples thereof include (La, Ca) 1 Mn 1 O y ; (La, Sr) 1 Mn 1 O y ; Bi 1 Mn 1 O y ; (La, A) Mn 1-x (Co, Fe, Ni) x O y wherein A represents at least one element selected from the group consisting of Ba, Sr, Pb, and Cd; (D, E) 1 Mn 1-x G x O y wherein D represents at least one rare earth element, E represents at least one alkaline earth element and G represents at least one element selected from the group consisting of Fe, Co, Ni, and Cr; {(Pr, Nd), (Ba, Sr)} 1 (Mn 1-x G x ) 1 O y (Bi, Ca) 1 (Mn 1-x G x ) 1 O y ; La 1 (Mn 1-x G x ) 1 O y ; Gd 1 (Mn 1-x G x ) 1 O y ; J(L, M) 1 O y wherein J represents at least one element selected from the group consisting of Ba, Ca, Sr, and Pb, L represents at least one element selected from the group consisting of Ni, Mn, Cr, and Fe, and M represents at least one element selected from the group consisting of W, Sb, Mo, and V; (Sr, La) 1 Mn 1-x Q x O y wherein Q represents at least one element selected from the group consisting of Co, Ni, Nb, Sb, and Ta; La 3 Mn 2 O z ; (La, J) 3 Mn 2 O z ; and (La, J) 3 (Mn, L) 2 O z , wherein, in the formulae, x=more than 0 to 3.5, y=2.7 to 3.3, and z=5 to 8. In the present specification, for example, "(La, Ca)" means that the material contains at least one of La and Ca.
The electrically insulating layer is formed of preferably an oxide having a perovskite structure, and examples of materials usable herein include RO y wherein R represents at least one element selected from the group consisting of Si, Ti, Mo, W, Zr, Ta, Cr, Al, Mg, Hf, and Ca and y is 1.4 to 2.2; DO y wherein D represents at least one rare earth element; JTiO z wherein J represents at least one element selected from the group consisting of Ba, Ca, Sr, and Pb, and z is 2.7 to 3.3; Pb 1 {(Zr, Ti), L} 1 O z wherein L represents at least one element selected from the group consisting of Ni, Mn, Cr, and Fe, said materials having an electric resistance of not less than 10 7 Ω·cm.
The thickness of the electrically insulating layer is preferably 0.001 to 1.0 μm, desirably 0.003 to 0.1 μm. The oxide magnetoresistive material should be physically strongly bonded to the magnetostrictive material, and, in the present invention, the insulating layer should be thin while maintaining the electrically insulating property. In the present invention, the thickness could be brought to about 0.1 μm by virtue of aligned epitaxial growth using the perovskite oxide.
The magnetostrictive material is preferably a ferromagnetic material, and use of crystalline metals, amorphous metals, and oxides is particularly preferred.
Preferred ferromagnetic, crystalline metals usable in the present invention include those represented by the general formulae DFe 2 , DFe 3 , D 6 Fe 23 , and D 2 Fe 17 wherein D represents at least one rare earth element.
Specific examples thereof include materials containing not less than 50% by volume of any one of the following material: TbFe 2 ; SmFe 2 ; T(Fe 1-x X x ) 2 ; T(Fe 1-x X x ) 3 ; T 6 (Fe 1-x X x ) 23 ; and T 2 (Fe 1-x X x ) 17 wherein T represents at least one element selected from the group consisting of Tb, Dy, Ho, Sm, Gd, Tm, and Er, X represents at least one element selected from the group consisting of Ti, V, Cr, Mn, Co, Ni, and Cu, and x is preferably more than 0 to 0.5. The term "crystalline metal" refers to all metals wherein a crystalline phase (not an amorphous phase) is present.
Preferred ferromagnetic, amorphous metals usable herein include those represented by the general formulae DFexMey, DFe 3 , D 6 Fe 23 , and D 2 Fe 17 wherein D represents at least one rare earth element, Me represents at least one element of semimetallic material, x is 1.8 to 10, and y is 0 to 0.1).
Specific examples of ferromagnetic, amorphous metals usable herein include materials containing not less than 50% by volume of any one of the following materials: TbFe 2 B 0 .01 ; SmFe 2 B 0 .01 ; T(Fe 1-x X x ) 2 Z y ; T(Fe 1-x X x ) 3 Z y ; T 6 (FE 1-x X x ) 23 Z y ; and T 2 (Fe 1-x X x ) 17 Z y wherein T represents at least one element selected from the group consisting of Tb, Dy, Ho, Sm, Gd, Tm, and Er, X represents at least one element selected from the group consisting of Ti, V, Cr, Mn, Co, Ni, and Cu, Z represents at least one element selected from the group consisting of B, C, Si, P, S, As, Se, Sb, and Te, x=more than 0 to 0.5, and y=more than 0 to 0.1.
Preferred magnetostrictive oxide magnetic materials usable herein include ferrite, iron having a spinel structure, and cobalt oxide.
Specific examples of oxide magnetostrictive materials usable in the present invention include NiFe 2 O 4 ; Co 1 Fe 2 O 4 ; Y 3 Fe 5 O 12 ; Fe 3 O 4 ; (Ba, Pb)Fe 2 O 4 ; and BaFe 12 O 19 .
The magnetic detecting element (magnetization-conduction interactive element) according to the present invention comprises: a laminate structure of a multilayer film comprising two or more layers formed of a magnetostrictive material and an oxide magnetoresistive material; a means for allowing a current to flow into the oxide magnetoresistive material; and a means for detecting a voltage created in the oxide magnetoresistive material. The laminate film comprises: a thin film of an oxide magnetoresistive material composed of an Mn-based perovskite oxide; and a ferromagnetic magnetostrictive material. The minimum unit has two layers. However, when the magnetostrictive material is electrically conductive, an insulating layer is provided between the two layers. In this case, the minimum unit has three layers.
The magnetic detector of the present invention comprises: a laminate structure of a multilayer film comprising two or more layers formed of a magnetostrictive material and an oxide magnetoresistive material; a means for allowing a current to flow into the oxide magnetoresistive material; a means for detecting a voltage created in the oxide magnetoresistive material; and a means for externally applying energy to the laminate film. The means for allowing a current to flow into the oxide magnetoresistive material is a means wherein a current is fed through electrodes of Pt, Ag, Au, Cu or the like. The voltage created at that time is monitored by a voltmeter. The terminals for detecting the voltage may be the same as those for feeding the current. An actuator, a switch element, and a power source as a load can be directly regulated by varying the current flowing through the oxide magnetoresistive material. In this case, only the terminals for allowing a current to flow are necessary.
Externally applying energy, such as electromagnetic wave, magnetic field, light, sound, pressure, or heat, to the magnetic detector causes the sequence of magnetic spins of manganese to respond thereto with a high sensitivity and to be changed. This change can be read as a change in voltage or current. Therefore, the magnetic detector can be utilized as a highly sensitive detector or actuator.
Further, the present invention provides a magnetic detector and a current control element, comprising: a substrate; a laminate film comprising an oxide magnetoresistive material provided onto the substrate and an electroconductive, crystalline magnetostrictive material or an electroconductive, amorphous magnetostrictive material laminated on the magnetoresistive material through an electrically insulating oxide layer; a means for allowing a current to flow into the oxide magnetoresistive material; and a means for detecting a voltage created in the oxide magnetoresistive material, magnetism being detected based on a change in electrical resistance of the laminate film in response to the magnetism in the case of the magnetic detector, magnetism being utilized to vary the current in the case of the current control element.
As another arrangement of the above laminate film, the magnetostrictive material is provided as a lower layer on the substrate and the oxide magnetoresistive material is provided as an upper layer through the insulating oxide layer.
Further, the present invention provides a magnetic detector and a current control element, comprising: a substrate; a laminate film comprising an oxide magnetoresistive material provided onto the substrate and an electrically insulating magnetostrictive material laminated on the oxide magnetoresistive material; a means for allowing a current to flow into the oxide magnetoresistive material; and a means for detecting a voltage created in the oxide magnetoresistive material, magnetism being detected based on a change in electrical resistance of the laminate film in response to the magnetism in the case of the magnetic detector, magnetism being utilized to vary the current in the case of the current control element.
As another embodiment of the laminate film, the film may be formed by laminating the electrically insulating magnetostrictive material and then the oxide magnetoresistive material onto the substrate.
The above magnetoresistive element comprising a laminate film may be used as a magnetic detector as follows.
In a three-layer film comprising an electrically insulating layer provided between the electroconductive magnetostrictive material and the oxide magnetoresistive material, an electrode is provided on the oxide magnetoresistive material and connected to the means for feeding a current. Further, an electrode for detecting the voltage in the three-layer structure portion of the film and a means for detecting this are connected. Application of a magnetic field to the element having such a three-layer film results in a change in electrical resistance of the oxide magnetoresistive material. When a current is allowed to flow into the electrode, a change in voltage in the electrode for detecting the voltage can be monitored, rendering the element utilizable in a magnetic field detecting element or detector.
On the other hand, in a two-layer film comprising an electrically insulating magnetostrictive material and an oxide magnetoresistive material, an electrode is provided on the oxide magnetoresistive material and connected to the means for feeding a current. Further, an electrode for detecting the voltage in the two-layer structure portion of the film and a means for detecting this are connected. Application of a magnetic field to the element having such a two-layer film results in a change in electrical resistance of the oxide magnetoresistive material. When a current is allowed to flow into the electrode, a change in voltage in the electrode for detecting the voltage can be monitored, rendering the element utilizable in a magnetic field detecting element or detector. This element has an advantage over the above element using an electroconductive magnetostrictive material in that the structure is simpler.
For the above construction, two current terminals for permitting a current to flow in the longitudinal direction within a film plane and two voltage terminals for detecting the voltage created at that time are provided in the laminate film on the substrate. Further, this assembly is fixed on a support and connected to a current supply means and a voltage detection means. In this state, external application of a magnetic field to the magnetic detector results in a change in voltage created in the voltage terminal depending upon the magnitude of the applied magnetic field, making it possible to detect the magnetic field. The current terminals may be the same as the voltage terminal.
The percentage voltage change in this case amounts to 500% to 1,000% which is larger by two or more orders than that attained by the conventional magnetoresistive element. The specific resistance of the oxide magnetoresistive material is 1 to 10 mΩ·cm, and the absolute value of the created voltage is increased 4 to 5 orders over that in the conventional magnetoresistive element. Therefore, a magnetic detecting element or detector having a high S/N ratio can be provided. Further, the current value during the operation of the element can be reduced to about several microamperes, inhibiting generation of heat in the electrode and the wiring section and preventing a deterioration of the magnetoresistive film caused by heat generation.
A metallic, magnetic material, such as a permalloy (Ni--Fe), has been mainly used in a ferromagnetic material for use in the conventional magnetic head, that is, in a magnetoresistive film. By contrast, according to the present invention, the specific resistance of the magnetic material is as high as several tens of μΩ·cm. Therefore, unlike the prior art wherein the magnetoresistive film in the element is brought to a very small thickness of not more than several hundreds of Å in order to provide high reproduction output, the present invention can eliminate the need to render the film very thin. Further, there is no need to increase the current fed into the element. Therefore, the preparation of the above film having such a small thickness is not required, and, in addition, a problem of a lowering in sensitivity derived from an increase in coercive force due to pinholes in the film is not posed. Furthermore, it is unnecessary to feed a large current, overcoming a problem that the deterioration of the element is accelerated due to heat generation or the like.
"Giant magnetoresistance effect" which is a phenomenon different from the above magnetoresistance effect has been proposed. The "giant magnetoresistance effect" refers to such a phenomenon that a very large magnetoresistance effect appears in a laminate film having a three-layer structure of a nonmagnetic material sandwiched between ferromagnetic materials. This phenomenon is created by spin interaction between the upper ferromagnetic material and the lower ferromagnetic material through the nonmagnetic layer. The magnetic detecting element or detector utilizing this phenomenon has a problem that the detection sensitivity is low although the reproduction output is somewhat high. According to the present invention, however, this problem can be solved.
Further, there is a ferromagnetic tunnel junction element as a magnetic detecting element based on a principle different from that of the above magnetic detecting element. This element comprises a very thin insulator, with a thickness of several tens of Å, sandwiched between thin films of a ferromagnetic material and can be utilized as a high-sensitivity and high-output magnetic detecting element. The ferromagnetic tunneling phenomenon occurs only at a very low temperature, making it difficult to apply this phenomenon to the magnetic detecting element. According to the present invention, however, this problem can be solved, and use of the element around room temperature is possible.
Further, the present invention provides a magnetic recording device adapted for reading a magnetic signal, recorded in a magnetic recording medium, with the aid of a magnetic detecting element, wherein the magnetic detecting element has a laminate film having a three-layer structure of an insulating oxide sandwiched between magnetic materials (i.e., the foregoing oxide magnetoresistive material and electroconductive crystalline or amorphous magnetostrictive material) and the laminate film reads a magnetic signal recorded in the magnetic recording medium. When the magnetic detecting element approaches the magnetic recording medium with information recording thereon, the magnetic field from the magnetic recording medium leads to a change in, for example, detection voltage, permitting information written in the magnetic recording medium to be read.
Further, the present invention provides a method for using a magnetic detector, the detector comprising a substrate; and a laminate film of an oxide magnetoresistive material provided on the substrate and an electrically insulating magnetostrictive material laminated onto the oxide magnetoresistive material, the magnetic detector being used in a wide temperature range of 50° K to 400° K by regulating the magnetic transition temperature of the oxide magnetoresistive material. Instead of the electrically insulating magnetostrictive material, an electroconductive oxide magnetostrictive material may be laminated on the oxide magnetoresistive material through the insulating oxide layer interposed therebetween.
Also, as set forth above, the magnetostrictive material and the oxide magnetoresistive material may be provided as a lower layer and an upper layer, respectively, in the foregoing two types of magnetic detectors.
The magnetoresistive element of the present invention can be used in a recording device in a computing system for a large-size computer, a personal computer or the like. Further, it can also be used as a recording device for an optical communication system or an optical operation system, or as an arithmetic element.
Preferably, the preparation of the laminate film having a two-layer structure by laminating an oxide magnetoresistive material and a magnetostrictive material or a three-layer structure by laminating an oxide magnetoresistive material and a magnetostrictive material with an insulating layer interposed between these materials may be done by sputtering, ion beam sputtering, vacuum deposition, laser ablation, coating from sol-gel followed by sintering, and the like. It is also possible to prepare the laminate film on a substrate, such as a single crystal substrate of lanthanum-aluminum oxide, a single crystal substrate of strontium titanate, a single crystal substrate of magnesium oxide, or a single crystal substrate of zirconium oxide. The substrate is preferably a glass substrate, a single crystal substrate of silicon, a single crystal substrate of gallium arsenic, a single crystal substrate of gadolinium gallium garnet or the like. Preferably, each magnetoresistive material layer and each magnetostrictive material layer are mutually grown in an epitaxial orientation relationship.
In the preparation of a laminate film, in the case of an oxide magnetoresistive material, the substrate temperature is set at an optimal temperature between 300° C. and 800° C., and an oxidizing atmosphere (such as O 2 , O 3 , N 2 O, NO 2 or the like) is introduced to prepare the oxide magnetoresistive material layer. In the case of an insulating layer, the substrate temperature is set at an optimal temperature between 300° C. and 800° C., and the insulating layer is then prepared in an oxidizing atmosphere (O 2 , O 3 , N 2 O, NO 2 or the like) or in vacuo. In the case of a metal, the substrate temperature is set at an optimal temperature between room temperature and 500° C., and the metallic layer is then prepared in an air atmosphere of not more than 10 -3 Torr, an inert gas atmosphere of not more than 1 Torr, or in vacuo. When the oxide film is formed by sputtering, laser deposition or coating, a sintered target or a raw material powder having a predetermined composition is preferably used, while in the case of vacuum deposition, an alloy vapor deposition source of a metal or an alloy having a predetermined chemical composition is preferably used.
The present invention may be used in a magnetic recording device as follows. A means for feeding a current to the magnetic detecting element according to the present invention and a means for detecting the voltage of the element are connected, and, separately from the magnetic detecting element, the element for writing an information signal on a magnetic recording medium, that is, the so-called "magnetic head for recording" is mounted on the same support. The support moves the element to a predetermined position of the magnetic recording medium by taking advantage of a drive system controlled by a control section so that an information signal can be written or read. This realizes a high-density, large-capacity, and small-size magnetic recording device.
When the laminate film according to the present invention is utilized in the magnetic detecting element, detector or recording device, it is preferably utilized at a temperature around the magnetic transition temperature of the oxide magnetoresistive material. This is because alignment-unalignment of the magnetization can be easily created by means of an external energy in this temperature range. Use of the laminate film according to the present invention in the above temperature range can realize a magnetic detecting element, detector or recording device having a high detection sensitivity and a high output unattainable by the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1(a) and FIG. 1(b) are cross-sectional views of two laminate films having a three-layer structure prepared by lamination.
FIG. 2(a) and FIG. 2(b) are cross-sectional views of two magnetic detectors prepared by lamination according to the present invention.
FIG. 3 is a diagram showing standardized electrical resistance as a function of applied magnetic field in the magnetic detector according to the present invention.
FIG. 4 is a schematic diagram showing another magnetic detecting element according to the present invention.
FIG. 5 is a diagram showing standardized electrical resistance as a function of applied magnetic field in another magnetic detecting element according to the present invention.
FIG. 6 is a schematic diagram showing an embodiment where the magnetoresistive element according the present invention has been applied to a domiciliary medical system.
FIG. 7 is a diagram showing a change in voltage as a function of time in an embodiment where the magnetoresistive element according to the present invention has been applied to a domiciliary medical system.
FIG. 8 is a schematic diagram showing an embodiment where the magnetoresistive element according to the present invention has been applied to an approach sensor.
FIG. 9 is a diagram showing the relationship of the distance, between an object and a magnetoresistive element, with the voltage in an embodiment where the magnetoresistive element according to the present invention has been applied to an approach sensor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Use of the oxide magnetoresistive material and the magnetostrictive material permits magnetostriction to apply strain to the oxide magnetoresistive material.
Further, use of the oxide magnetoresistive material and the magnetostrictive material permits the magnetic transition temperature of the oxide magnetoresistive material to be varied.
Use of the oxide magnetoresistive material and the magnetostrictive material changes the magnetization-conduction interaction of the oxide magnetoresistive material. Upon application of a magnetic field, the magnetization of the oxide magnetoresistive material is created. At the same time, application of strain to the oxide magnetoresistive material by the magnetostrictive material raises the magnetic transition temperature, and the magnetization of the oxide magnetoresistive material is created at a temperature around the magnetic transition temperature. Creation of the magnetization results in a change in electrical conductivity from a semiconductive or insulating property to a metallic property. This creates a giant magnetoresistance effect in the laminate film of the oxide magnetoresistive material and the magnetostrictive material, making it possible to provide a high-sensitivity, high-output element utilizable as a magnetic detecting element or detector.
Further, in a laminate film having a two-layer structure prepared by laminating an oxide magnetoresistive material and a magnetostrictive material onto a substrate or a three-layer structure prepared by laminating an oxide magnetoresistive material, a magnetostrictive material, and an insulating layer provided between the oxide magnetoresistive material and the magnetostrictive material, a current is fed into the oxide magnetoresistive material, and a magnetic field is externally applied. This permits the applied magnetic field to increase the magnetization of the magnetoresistive material at a temperature around the magnetic transition temperature, and, at the same time, the magnetostrictive material is strained by the magnetic field, causing the magnetoresistive oxide to be also strained. This in turn changes the magnetic transition temperature, and the magnetization-conduction interaction functions so that the voltage created in the laminate section changes according to the magnetic field.
Further, when the magnetic detecting element of the present invention is used as a means for reading a signal recorded in the magnetic recording medium, the voltage created in the element varies depending upon the magnetic field applied from the magnetic recording medium to the element.
EXAMPLES
Embodiments of the present invention will be described with reference to FIG. 1(a) and FIG. 1(b).
FIGS. 1(a) and (b) are cross-sectional views of two respective laminate films having a three-layer structure on the substrate 11. In FIGS. 1(a) and 1(b), numeral 12 designates an oxide magnetoresistive material layer, numeral 13 an insulating layer, and numeral 14 a magnetostrictive material layer. In this case, the insulating layer was formed of SrTiO x (wherein x is 2.7 to 3.3), the oxide magnetoresistive material was La 1-x Sr x MnO y (wherein x is 0.15 to 0.3 and y is 2.7 to 3.3), and the magnetostrictive material was SmFe 2 , SmFe 2 B 0 .01, or Co 2 Fe 2 O 4 . In this case, as shown in FIGS. 1(a) and (b), any of the oxide magnetoresistive material and the magnetostrictive material may be laminated as an upper layer through the insulating layer. Further, a single crystal which had been subjected to mirror polishing was used as the substrate 11.
Regarding the thickness of the layers constituting the laminate film having a three-layer structure, a 10 nm-thick insulating layer 13, a 100 nm-thick oxide magnetoresistive material layer 12, and a 500 nm-thick magnetostrictive material layer 14 were formed on an LaAlO 3 (100) substrate 11 having a size of 10 mm×10 mm×0.5 mm. When the magnetostrictive material is not electrically conductive, the insulating layer 13 may be omitted.
One example of film forming conditions for an electroconductive magnetostrictive material is summarized in Table 1, and one example of film forming conditions for a magnetostrictive material not having an electrical conductive property is summarized in Table 2.
Table 1
Oxide magnetoresistive material layer
Layer species: La 0 .75 Nd 0 .05 Sr 0 .15 Ca 0 .05 MnO y
[LNSCMO]
Layer forming method: Laser vapor deposition
Substrate: Single crystal LaAlO 3 (100) face
Substrate temperature: 650° C.
Gas species/partial pressure: Oxygen
Atmosphere/total pressure: 1×10 -4 Torr
Laser energy: 1 J/cm 2 /pulse×10 Hz
Layer formation rate: 0.05 nm/sec
Layer thickness: 100 nm
Insulating layer
Layer species: SrTiO 2
Layer forming method: Laser vapor deposition
Substrate: On LNSCMO
Substrate temperature: 400° C.
Gas species/partial pressure: Oxygen
Atmosphere/total pressure: 1×10 -4 Torr
Laser energy: 1 J/cm 2 /pulse×10 Hz
Layer formation rate: 0.05 nm/sec
Layer thickness: 10 nm
Magnetostriction layer
Layer species: SmFe 2
Layer forming method: DC magnetron sputtering
Substrate: On SrTiO 2
Substrate temperature: 200° C.
Gas species: Ar
Total pressure: 2×10 -4 Torr
Sputtering energy: 600 V×0.2 A
Layer formation rate: 0.5 nm/sec
Layer thickness: 500 nm
Table 2
Oxide magnetoresistive material layer
Layer species: La 0 .75 Nd 0 .05 Sr 0 .15 Ca 0 .05 MnO y
[LNSCMO]
Layer forming method: Laser vapor deposition
Substrate: Single crystal LaAlO 3 (100) face
Substrate temperature: 650° C.
Gas species/partial pressure: Oxygen
Atmosphere/total pressure: 1×10 -4 Torr
Laser energy: 1 J/cm 2 /pulse×10 Hz
Layer formation rate: 0.05 nm/sec
Layer thickness: 100 nm
Magnetostriction layer
Layer species: Co 2 Fe 2 O z
Layer forming method: Laser vapor deposition
Substrate: On LNSCMO
Substrate temperature: 550° C.
Gas species/partial pressure: Oxygen
Atmosphere/total pressure: 1×10 -4 Torr
Laser energy: 1 J/cm 2 /pulse×10 Hz
Layer formation rate: 0.05 nm/sec
Layer thickness: 500 nm
Embodiments of an application of the laminate film having a three-layer structure or a two-layer structure to a magnetic detector are shown in FIG. 2(a) and FIG. 2(b). FIG. 2(a) and FIG. 2(b) are schematic cross-sectional views of magnetic detectors.
In the preparation of the magnetic detector shown in FIGS. 2(a) and (b), an oxide magnetoresistive material layer 22 of La 0 .75 Nd 0 .05 Sr 0 .15 Ca 0 .05 MnO z (wherein z is 2.7 to 3.3), an insulating layer 23 of SrTiOy (wherein y is 2.7 to 3.3), and a magnetostrictive material layer 24 of SmFe 2 are formed in that order on a substrate 21 of a single crystal LaAlO 3 in the same manner as described above [FIG. 2(a)]. Alternatively, a magnetostrictive material layer 24 of SmFe 2 , an insulating layer 23 of SrTiOy (wherein y is 2.7 to 3.3), and an oxide magnetoresistive material layer 22 of La 0 .75 Nd 0 .05 Sr 0 .15 Ca 0 .05 MnO z (wherein z is 2.7 to 3.3) are formed in that order on a substrate 21 of a single crystal LaAlO 3 in the same manner as described above [FIG. 2(b)].
Electrodes 25 of Pt for applying a current to the oxide magnetoresistive material 22 are formed on the oxide magnetoresistive material 22. In FIGS. 2(a) and (b), numeral 27 designates a current source, for applying a current through the electrode 25, which permits a current of 1 μA to flow into the oxide magnetoresistive layer 22.
Electrodes 26 of Pt are formed so that the voltage created in the laminate section upon application of a current to the oxide magnetoresistive material 22 can be detected with a voltmeter 28.
Application of a magnetic field in the range of -1 kOe to 1 kOe to the detector so as to be parallel to the oxide magnetoresistive material layer causes the electrical resistance of the oxide magnetoresistive material to be changed in response to the magnetic field, resulting in a change in a voltage between the electrodes 26.
A change in created voltage as a function of the applied magnetic field is shown in FIG. 3. In FIG. 3, the abscissa represents the applied magnetic field, while the ordinate represents a change in voltage (ΔV) based on the voltage created with no magnetic field being applied. A ΔV value of 0.5 indicates the creation of a voltage which is half the voltage created with no magnetic field being applied. FIG. 3 shows that a change of the external magnetic field by 1 kOe results in a change of the voltage by 0.9. This value is not less than two orders larger than that provided by the conventional magnetoresistive element, for example, a magnetoresistive element using a magnetic film of a permalloy. Utilization of this property can realize a magnetic detecting element having high sensitivity.
Another embodiment of the present invention will be described with reference to FIG. 4. FIG. 4 is a schematic diagram showing the magnetic detector according to the present invention. The magnetoresistive element shown in FIG. 4 comprises a substrate 41 of an MgO single crystal and a laminate film 46, of the present invention, provided on the substrate. The laminate film 46 was proceeded by photolithography and ion milling to a shape of 50×200 μm in longitudinal and width dimension. In the formation of the laminate film 46, a 500 nm-thick layer of a amorphous supermagnetostrictive material SmFe 2 is formed by sputtering, a 10 nm-thick layer of an insulating oxide SrTiO 3 is formed thereon, and a layer of an oxide magnetoresistive material La 0 .75 Nd 0 .05 Sr 0 .15 Ca 0 .05 MnP y (wherein y is 2.7 to 3.3) is formed by laser ablation. A current of 1 μA is fed from the electrode toward the film surface direction of the laminate film 46. In FIG. 4, numeral 47 designates a voltmeter which serves to detect the voltage created in the laminate film 46. Application of a magnetic field 49 in the range of -100 Oe to 100 Oe to the element so as to be parallel to the film surface of the element caused the voltage detected to be varied depending upon the intensity of the magnetic field. A change in created voltage as a function of the applied magnetic field is shown in FIG. 5. In FIG. 5, the abscissa represents the intensity of the applied magnetic field, while the ordinate represents a change in voltage (ΔV) according to a change in magnetic field as in FIG. 3. A magnetic field of 50 Oe causes a ΔV value of 0.8, indicating that the voltage is about 80% lower than that created with the magnetic field being zero. This voltage change is not less than one order larger than that in the conventional magnetoresistive element. Utilization of the laminate film according to the present invention can realize a high-sensitivity, high-output magnetic detecting element.
The magnetoresistive element according to the present invention can be used as a head for a magnetic recording device by virtue of the above-described magnetoresistance effect, that is, good magnetic sensitivity and output and low power consumption.
Further, the magnetoresistive element according to the present invention can be applied to a rotation angle sensor, a position sensor, a linear gauge sensor and the like.
An embodiment where the magnetoresistive element according to the present invention has been utilized in a domiciliary medical device will be described. FIG. 6 is a schematic diagram showing a domiciliary treatment device. The domiciliary treatment device shown in FIG. 6 is used to monitor the breathing of a bedridden patient or old man or woman who needs care. Numeral 63 designates a bedridden patient or old man or woman, and numeral 61 a permanent magnet placed on the breast of the bedridden patient or old man or woman. Numeral 64 designates a bed. Upon breathing, the magnet 61 periodically moves in a vertical direction. The movement of the magnet 61 corresponds to a variation in distance, in other words, a change in intensity of the magnetic field, for the magnetoresistive element of the present invention indicated by a reference numeral 62.
The magnetoresistive element 62 detects a change, in position of the magnet 61 caused by the person's breathing, as a change in magnetic field. This change is converted by means of a detector 65 to a change in voltage or a change in current derived from a change in electrical resistance to continue monitoring of the periodical displacement of the magnet 61. In this case, when there is no periodical displacement of the magnet 61, a signal is electrically or optically sent to an alarm device 66. This alarm device can be connected to a centralized monitoring system linked with an alarm, such as a buzzer, and a communication system.
A change in voltage obtained from a magnetoresistive element in the domiciliary medical device according to the present invention is shown in FIG. 7. FIG. 7 shows a change in voltage as a function of time. As shown in FIG. 7, breathing causes the magnet to be vertically moved to change the distance between the magnet and magnetoresistive element 62. This results in a change in intensity of the magnetic field which the magnetoresistive element 62 receives, causing a change in electrical resistance. The magnitude of the change is as large as several % and several mV in terms of voltage. Such a large change in voltage can be easily subjected to signal processing and enables the condition of the bedridden patient or old man or woman to be surely and accurately learned by using an inexpensive signal processor alone.
Use of a detection system utilizing the magnetoresistance effect according to the present invention permits domiciliary care for a bedridden patient or old man or woman, which has been expensive in the prior art, to be inexpensively and accurately done.
An embodiment where the magnetic detecting element according to the present invention has been utilized in an approach sensor is described. FIG. 8 is a schematic diagram showing the use of an approach sensor in a sensor used for putting a car in a garage. Numeral 81 designates a garage or a carport, and numeral 82 a car. The direction of advance of the car is indicated by an arrow. When the car 82 is put in the garage or carport 81, a magnetoresistive element 83 is placed in a position, where the car approaches the garage or carport, and connected to a controller and an alarm device 84. The controller and alarm device 84 functions to permit a current to flow into the magnetoresistive element 83, to measure the voltage or current, to deliver the results of measurement to the alarm device, and to inform a driver of the results by taking advantage of a sound, light or the like.
A change in voltage, in the case where a current of 1 μA is allowed to flow into the magnetoresistive element 83 and a magnetized iron or magnet is allowed to approach, is shown in FIG. 9. In FIG. 9, the abscissa represents the distance between the magnetoresistive element and the magnetized iron or magnet, while the ordinate represents the voltage created with a current of 1 μA being fed into the magnetoresistive element. When the magnetized iron approaches the magnetoresistive element, the voltage becomes half at a distance between the magnetized iron and the magnetoresistive element of 2 to 3 cm. In the case of a ferrite magnet, the voltage becomes half at a distance of about 10 cm. Therefore, the distance can be measured by monitoring the voltage or current. Further, the sensor section of this system comprises a magnetoresistive element and, hence, is very simple in structure, highly reliable, and inexpensive.
According to the present invention, a magnetic detecting element having high sensitivity and good quick response can be provided, making it possible to provide housing equipment, medical equipment, environmental equipment, a magnetic recording device, and a magnetic measuring instrument.
According to the present invention, the approach sensor, as compared with the conventional approach sensor of mechanical, optical, dielectric or other type, is inexpensive, has better reproducibility, and needs simpler maintenance. Further, as compared with the conventional medical monitoring system, the monitoring system is less likely to influence the patient, has higher reliability, and is inexpensive. Further, when the present invention is applied to a magnetic head for magnetic recording, it is possible to provide an element having low power consumption and high output.
Further, according to the present invention, large magnetoresistance effect can be provided at room temperature by virtue of synergistic effect of the magnetostriction and the magnetoresistance effect, eliminating the need to provide cooling equipment.
Further, according to the present invention, a large voltage output is obtained even when the current value for detecting the voltage is reduced, offering an advantage that a deterioration of the element due to the generation of heat or the like can be prevented. Furthermore, according to the present invention, the voltage output is so high that there is no influence of noise created at the time of production of a signal. Thus, the detection device can be simplified, and a system is provided at a low cost.
Furthermore, according to the present invention, the change in resistance is so large that application of a given voltage results in a large change in current value, advantageously rendering the present invention usable in current control. | A magnetoresistive element comprising a combination of an electroconductive, crystalline magnetostrictive material or an amorphous magnetostrictive material with an electrically insulating layer and an oxide magnetoresistive material, or a combination of an electrically insulating oxide magnetostrictive material with an oxide magnetoresistive material. The magnetoresistive element provides a magnetic detecting element, detector or recording device having high sensitivity and good quick response by virtue of synergistic effect of the large magnetostriction and the magnetoresistance effect thereof. The oxide magnetoresistive material is preferably an oxide having a perovskite structure or a layer perovskite structure and the preferred magnetostrictive material is a crystalline or amorphous ferromagnetic material. The electrically insulating layer is formed of preferably an oxide having a perovskite structure. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to suspended ceilings and, in particular, to systems employing torsion spring mounted panels.
PRIOR ART
Torsion spring mounted ceiling panels have generally been limited to use in systems in which a supporting grid and the panels themselves are rectangular. This convention has limited the look of ceiling installations to rectangular patterns. Architects, interior designers, building tenants and owners want distinctive ceiling treatments.
SUMMARY OF THE INVENTION
The invention provides a suspended ceiling system that affords a distinctive, non-rectangular geometric look. The system includes a suspension grid and complementary torsion spring supported rhomboidal panels. The inventive system allows the panels to be of most any rhomboid shape, equivalent in size to conventional ceiling panels, as specified by a designer. In the disclosed system, the grid has main runners or tees in parallel relation, typically spaced on four foot or two foot centers. Panel support bars extend between adjacent tees at a predetermined oblique angle. The disclosed bars can have a channel-shape cross-section with a lower web having slots for receiving torsion springs and locating tabs on edges of the panels. Flanges of the bar upstanding from the web have notched ends configured to fit over a tee flange while the web underlies the tee flange. This construction allows the bars, when being installed, to be supported on and slid along the respective tees to a desired location. Bar ends on opposite sides of a tee can be aligned by a bridge plate assembled over the top of a tee and abutted against the bar flange ends. The bars are fixed on the tees by screws assembled through the bar web ends and the overlying tee flange areas. Slots on the bars for receiving the panel torsion springs and locating tabs of adjacent panels are offset or staggered in accordance with the invention to accurately locate the panel edges along straight sight lines.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a somewhat schematic plan view of a portion of a chevron shaped ceiling construction employing the invention;
FIG. 2 is a plan view of a long right hand bar used in the grid of FIG. 1 ;
FIG. 3 is a plan view of a short right hand bar used in the grid of FIG. 1 ;
FIG. 4 is a cross-sectional view typical of the bars of FIGS. 2 and 3 ;
FIG. 5 is a fragmentary plan view on an enlarged scale showing details of apertures for springs and locating tabs at a typical spring center of the long and short bars;
FIG. 6 is a perspective view of an end typical of the bars;
FIG. 7 is a perspective view of a bar splice plate;
FIG. 8 is a plan view of a large right hand panel;
FIG. 9 is a plan view of a small right hand panel;
FIG. 10 is a typical cross-sectional view of an edge of the panels of FIGS. 8 and 9 ;
FIG. 11 is a fragmentary perspective view of a panel with a torsion spring clip with integral locating tabs and assembled with a torsion spring;
FIG. 12 is a perspective view of two bar ends intersecting a main tee from opposite sides and aligned with the splice plate; and
FIG. 13 is a perspective fragmentary view of two adjacent panels and their torsion springs at a spring center of a common bar.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a suspended ceiling 10 employing rhomboidal panels 11 a , 11 b arranged in a chevron pattern. As shown, the panels 11 a , 11 b can be of different size and can be of right or left hand shape. The panels 11 are suspended on a grid of parallel tees or runners 12 and parallel bars 13 a , 13 b obliquely intersecting the tees 12 . Where the panels 11 form of a chevron pattern, the bars, like the panels 11 , are provided in symmetrical right and left hand versions.
The tees 12 can be conventional suspended ceiling main tees or runners well known in the industry. The bars 13 are unique and their geometry will depend on the acute angle selected for the rhomboid shape of the panels 11 . In the illustrated case, the acute angle has been selected to be 52 degrees.
In the disclosed arrangement, the elongated bars 15 are provided in two different lengths. The shorter bar being designated 13 a and the longer bar being designated 13 b . The illustrated bars 13 are formed as sheet metal channels that are installed hollow side up. FIG. 4 illustrates a typical cross-section of a bar 13 shown with a horizontal web 14 and upstanding flanges 15 extending vertically from longitudinal margins of the web 14 .
FIGS. 2 and 3 illustrate right hand versions of the bars 13 . The longer bars 13 b have four torsion spring locations 17 and the short bars 13 a have two torsion spring locations 17 . Where the main tees 12 have a nominal center-to-center spacing of four foot, the longer bars 13 b have a length of about 60.4 inches so that at a 52 degree angle relative to the tees, they will span between two adjacent tees. Similarly, the shorter bars 13 a with nominal lengths of about 30.3 inches and 52 degree orientations span between tees 12 on two foot centers. Left hand versions of the bars 13 are symmetrical and have the same dimensions.
A typical end construction of a bar 13 is illustrated in FIG. 6 . Material is removed at the juncture of the web 14 and flanges 15 to form a clearance slot 21 at the end of each flange and to form a cantilevered tongue area 22 . The clearance slot 21 is widened at an inner part for clearance of a conventional hem 23 ( FIG. 12 ) on a flange 24 of a tee 12 . Holes 26 , 27 are punched in the flanges 15 and tongue 22 for fixing a bar 13 in an installed position as described below.
Torsion springs 31 ( FIG. 11 ) and associated locating tabs 32 of a ceiling panel 11 are received in respective apertures or slots 56 , 57 ( FIG. 5 ) punched in the bar web 14 at spring locations 17 indicated in FIGS. 2 and 3 .
A bar 13 is installed on a pair of adjacent tees 12 by locating flange end portions 37 over the tee flange 24 ( FIG. 12 ). The bar flange portions 37 can support the bars 13 on the tees 12 and allow the bars 13 to slide on the tee flanges 24 until they are in a desired position.
As depicted in FIG. 12 , the bar 13 on opposite sides of a tee 12 can be mutually aligned with a bridging splice plate 38 ( FIG. 7 ). The plate 38 is preferably a sheet metal stamping with a central slot 41 open at a bottom edge and a stiffening flange 42 at a top. The slot 41 provides clearance for an upper reinforcing bulb 43 of a tee 12 . The plate 38 has preformed holes 44 for screws used to attach the plate to the flanges 15 of the bars 13 being aligned. The plate 38 is abutted and fixed with screws against flanges 15 of the pair of bars 13 being aligned. A bar 13 , once properly located on a tee 12 is fixed in position by driving screws through holes 27 in the bar tongue 22 into the overlying flange 24 of the supporting tee 12 .
FIGS. 8 and 9 illustrate two examples of right hand rhomboid panels, both being nominally 24 inches wide. The smaller panel 12 a measures 15.743 inches between two sides that extend obliquely to the 24 inch width and the large panel 12 b measuring nominally 42 inches on two sides extending perpendicularly to the 24 inch width. For a chevron ceiling design such as shown in FIG. 1 , both right and left hand symmetrical panels 11 and bars 13 are utilized.
The panels 11 are typically made of sheet metal such as aluminum. The panels are bent up at their edges to provide sidewalls or sides 46 that stiffen the panel. A panel 11 , inward of its sides 46 is ordinarily flat and made be perforated to afford sound absorption characteristics. All of the panel sides 46 are preferably over-bent to an angle, with reference to the panel center, of 88 degrees, for example, as shown in FIG. 10 .
Sides of the panels 11 that extend between the sides 46 associated with the nominal width of the panel are fitted on their interiors with clips 51 , two per side ( FIG. 11 ). The clips 51 , which are riveted or otherwise fastened to a panel side 46 , each carry a torsion spring 31 and provide a pair of integral alignment tabs 32 . The clips 51 and torsion springs 32 , as well as their functions, are known, for example, from U.S. Pat. No. 9,228,347.
The panels 11 are arranged beneath the grid formed by the tees 12 and bars 13 so that the torsion springs are aligned with the torsion spring locations 17 of the bars 13 . Referring to the plan view of FIG. 5 , each spring location 17 of a bar 13 has apertures 56 , 57 , respectively, to receive the torsion spring and the alignment or locating tab pair of each clip 51 of two side-by-side panels 11 underlying the bar. The square apertures 57 are configured to accurately locate the tabs 32 , and therefore an associated panel 11 , longitudinally and laterally on the respective bar 13 . The elongated apertures or slots 56 receive the arms of the torsion springs 31 allowing the springs to draw a panel side up against the bar 13 and allow the panel to be manually pulled down, against the force of the spring, away from the bar for access to the plenum above the ceiling 10 .
Close inspection of FIG. 5 reveals that a set of the apertures 56 , 57 for one panel, i.e. a set to one side of a longitudinal center line 60 of the web 14 of a bar 13 is longitudinally offset from the other set. It has been discovered that this offset adjustment allows adjacent panels to accurately align at the edges of their lower faces.
Where the panel acute angle is, for example, 52 degrees and the lateral spacing between the tab receiving apertures 57 , i.e. between apertures on opposed sides of a longitudinal center of the bar web, is 0.688 inches, the longitudinal offset can be 0.146 inch. This offset is evenly split longitudinally between each aperture set from a specified center of the spring location 17 on the longitudinal center line 60 of the bar web 14 . The offset is in a direction where a line drawn between mid-points of adjacent apertures 57 for tabs of adjacent panels tends to be aligned with the direction of those panel edges without springs.
The pattern of panels of FIG. 1 can be extended laterally and/or longitudinally or without any such extension can be repeated laterally.
Different ceiling aesthetics can be achieved with variations in the position of the tees 12 from a common single horizontal plane. For example, tees 12 on opposite sides of an intermediate tee 12 can be at a lower or a higher horizontal plane giving the ceiling a concave or a convex appearance from below. In such instances, the 88 degree over-bend of the panel sides or sidewalls 46 of the panels 11 avoid unsightly gaps at the panel edges. Still further, the tees 12 can be arranged to rise and fall at prescribed nodes where the tees are partially cut while leaving their flanges 24 intact but otherwise acting as a hinge. In these situations, the bars 13 are arranged to follow the local elevations of the tees 12 to which they are fixed.
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited. | A suspended ceiling system comprising a plurality of spaced parallel main runners, a plurality of spaced parallel panel support bars intersecting and being fixed to the main runners at an oblique angle, a plurality of rhomboidal panels having angles equal to said oblique angle suspended from the bars, the panels having nominal width dimensions that are equal to or whole fractions of a distance between adjacent runners, the panels having opposed first edges extending perpendicularly to a direction in which a width of a panel is measured and opposed second parallel edges extending in a direction that is at said oblique angle relative to a direction that the first edges extend, the second panel edges underlying respective bars and having attached torsion springs received in slots formed in the bars. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a construction element and, more particularly, to a construction element that accumulates latent heat.
2. Brief Description of the Prior Art
CH-A-688 describes a construction element that accumulates latent heat. One of the walls of a space is enclosed from the exterior by a wall which has on the outside a transparent thermal insulation and on the inside a space formed by two panes. This space is occupied by a substance that accumulates latent heat, such as calcium chloride hexahydrate, for example.
SUMMARY OF THE INVENTION
The object of this invention is to develop a construction element so that it is more efficient in terms of light absorption. This object is accomplished by a construction element that includes at least one first transparent pane and a second pane parallel to said first pane, which second pane contains a material that accumulates latent heat, wherein the material that accumulates latent heat is dyed or pigmented so that it absorbs light, at least in the infrared range of the solar spectrum.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in greater detail below with reference to the exemplary embodiments that are illustrated in the accompanying drawings, and in which:
FIGS. 1-6 show cross sections through different embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The construction element illustrated in FIG. 1 consists of transparent panes 10 , 11 that can be fabricated from glass or plastic. They form a space between them. This space is sealed and filled with a material 12 that accumulates latent heat. The heat of melting of the material 12 that accumulates latent heat is utilized to store thermal energy. Preference is given to the use of a material that melts at room temperature, such as calcium chloride hexahydrate or paraffin. In this manner, it becomes possible during the melting process in the range of room temperature to store several times more thermal energy in the material that accumulates latent heat than in conventional construction materials such as concrete or brick. These materials are poured into the space at temperatures that are above the melting point or are co-extruded with the panes 10 , 11 . It is also possible to introduce the material that accumulates latent heat between the panes 10 , 11 in solid form. The air in the minimal voids is then advantageously evacuated, so that it does not adversely affect the thermal conduction of the construction element. When paraffin is used as the material that accumulates latent heat, it is also possible to also make the paraffin retain its shape even during the solid/liquid phase transition by using supporting materials. The paraffin is distributed in the supporting material completely uniformly, and no liquid paraffin escapes even at high operating temperatures. An additional method of introducing the paraffin between the panes 10 , 11 so that it retains its shape is to enclose the paraffin in sealed hollow bodies 25 , so that these hollow bodies filled with paraffin can be stacked in a dry process between the panes 10 , 11 . These hollow bodies are advantageously fabricated from plastic. Some or all of the static pressure that is produced by the stacked hollow bodies 25 can thereby be used to make the hollow bodies 25 adhere to one another and to the panes 10 and 11 . The result is a static composite structure that also increases the stability of the panes 10 , 11 .
The material 12 that accumulates the latent heat is dyed or pigmented so that it absorbs light in the infrared range of the solar spectrum. It is preferably a dark color, so that the sunlight is absorbed directly in the material 12 that accumulates latent heat. The absorbed energy is stored in the form of thermal energy in the material that accumulates latent heat and is discharged slowly and continuously in the form of thermal radiation into the interior of the room. This color must be dark enough that as much incident solar radiation as possible is absorbed by the material 12 that accumulates latent heat without overheating the interior of the room with the transmitted solar radiation. The absorptivity of the coloring must be determined as a function of the location and the type of construction of the building. For example, on a building that uses lightweight construction, where the construction element forms an exterior wall directly, more light is absorbed in the material that accumulates latent heat than in a building with a more solid construction, in which the construction is a facade element that covers a wall. Other factors that must also be taken into consideration include the conventional window area of the facades facing the sun and the expected solar radiation at the location of the building. During the absorption of sunlight in the material 12 that accumulates latent heat, the characteristics of the material are also utilized to advantage. The latent heat storage material paraffin transmits significantly more light in its liquid state than in the solid state. It also has poor thermal conductivity. That means that when the layer of material that accumulates latent heat is exposed to solar radiation, it melts slowly from the outside to the inside, and thus the light transmission also increases from the outside to the inside. Consequently, the solar radiation ideally reaches the entire layer of material that accumulates latent heat and is stored where it is absorbed. So that the solar radiation can more effectively melt the paraffin 12 , the hollow bodies 25 are provided with depressions 26 or openings to create apertures for the entry of light. The solar radiation that comes through the apertures travels deeper into the layer of material 12 that accumulates latent heat.
A further possibility of increasing the degree of absorption of the construction element is to color the transparent panes 10 , 11 or the hollow bodies 25 a dark color, to paint them a dark color or to provide them with a dark coating. These colorings or coatings of the panes 10 , 11 and of the hollow bodies 25 can also be used for decorative purposes.
Facing the outside of the building, the panes 10 , 11 are lined on the outside with a transparent thermal insulation 13 which is enclosed by one or more additional transparent panes 14 . The thermal insulation 13 can be realized, for example, as described in WO 98/51973, which is incorporated into this application by reference. The pane 14 is advantageously made of low-iron flint glass with a high light transmittance to optimize the transmission of light. For the transparent insulating layer 13 , transparent plastic honeycomb or other transparent hollow chamber constructions can also be used. These transparent thermal insulators 13 have the characteristic that the air that is enclosed in the hollow chambers acts as an insulator, while the hollow chambers are so small that the convection of the air is eliminated.
The transparent thermal insulation can also be used to fill the space between the center pane 11 and the outer pane(s) 14 with an inert gas, e.g. argon, krypton or xenon, that is an effective thermal insulator. An additional possibility is to evacuate the air in this space. A vacuum is an ideal insulator. The middle panes 11 and 14 can have a thermal insulating coating 15 ( FIG. 2 ) on the outside or inside that is also called a Low-E coating. The outer flint glass pane 14 and the gas or vacuum layer behind it have high light transmittance. The middle glass pane 11 that is coated with thermal insulation naturally has a reduced degree of total energy transmission. The incident absorption energy is not lost energy, but is diverted inward into the material that accumulates the latent heat, because the outside insulating layer and the thermal protection coating 15 prevent any thermal loss to the exterior.
So that the thermal element does not overheat in summer, there is a shading on the outside of the layer of material that accumulates latent heat. In the exemplary embodiment illustrated in FIG. 2 , the shading device 16 is located in the outer insulating space behind the external glass pane 14 . This arrangement guarantees that the construction element with protection against overheating is manufactured in the form of a stable, efficient and reliable unit that does not require the use of additional shading constructions.
An additional possible way of regulating the radiation results from the fact that the outer pane 24 has prismatic elevations 17 . By deflecting the light, the sunlight that is incident at a higher angle in the summer is deflected outward while the sunlight that is incident at a lower angle can pass through the pane 24 unhindered. The prisms 17 can be located both on the front side and on the reverse side of the pane 14 . The principle of deflected light can also be used to product holograms, although such applications are still relatively complex and expensive. The construction element can also be used as a heating element. In a solar-heated house, additional heating sources are also required to provide the make-up heat that is required in bad weather. The pane 10 can be realized in the form of an electrical flat resistance radiator 18 facing the material 12 that accumulates the latent heat. For this purpose, conductive metal coatings are applied to the glass pane 10 . An additional possibility is to integrate pipes 19 that carry water into the latent heat storage system, and as in a flat radiator, the water gives up its heat to the material that accumulates the latent heat as necessary. The material 12 that accumulates the latent heat makes it possible to feed cheaper night-rate electricity into the material that accumulates the latent heat, which can be then used later during the day in the form of heat.
An additional possible protection against summertime overheating is a metal oxide coating on the outside of the panes 14 or 11 . The greater the incident angle with reference to a line perpendicular to the panes 14 , 11 , the greater the reflection on the outer surface of the panes 14 , 11 . In other words, summer sunlight that is incident at a steeper angle is reflected to a greater extent than winter sunlight that is incident at a lower angle. This configuration is also an economical solution.
To optimize the economy of the construction element, it can be extruded in the form of a one-piece plastic element. When the material 12 that accumulates the latent heat is loose, macroscopic cavities 20 are required to hold the material 12 that accumulates the latent heat, which material does not retain its shape in its liquid state. It is advantageous if the amount of transparent plastic used to form the cavities 20 in the panes 10 , 11 is minimized and the cavities are simultaneously realized so that they have a maximum capacity. This configuration can result in lattice-like structures as illustrated in FIG. 5 . To optimize the efficiency of the web plates, especially in winter, the webs 21 , 22 can form an acute angle with the pane 14 . | The invention relates to a construction element that comprises at least one first transparent pane and a parallel second pane that is at least partly transparent and contains a material that accumulates latent heat. The material that accumulates latent heat is dyed or pigmented so that it absorbs light in the infrared range of the solar spectrum. The construction element claimed by the invention is highly efficient in absorbing light directly in the material that accumulates latent heat. | 8 |
The Government of the United States of America has rights in this invention pursuant to Contract DEN3-32 awarded by the U.S. Department of Energy.
FIELD OF THE INVENTION
This invention relates generally to heat exchangers and more particularly to heat exchangers of annular configuration which utilize ceramic materials and which are especially advantageous for use as preheaters in hot gas Stirling type engines.
BACKGROUND OF THE INVENTION
The desirability of using ceramic materials in heat exchangers has been recognized, however, attempts to provide practical, effective, long life, low cost and reliable heat exchangers of annular configuration employing ceramic materials have not heretofore been entirely successful. Among the difficulties encountered are those relating to maintaining a long-lived and effective seal between the ceramic materials and the metallic mounting means therefor. This is due, in part at least, to the different coefficients of thermal expansion of the different materials. To operate efficiently, the two fluid streams of a heat exchanger must be isolated from each other and not allowed to leak. Leakage has typically been a problem at the interface of the near zero thermal growth ceramic material and the metallic mounting means.
Moreover, another sealing difficulty arises when attempting to provide heat exchangers of annular configuration using ceramic materials. A low cost, continuously annular ceramic construction is not possible with current processing techniques. A low cost and desirable ceramic heat exchanger element that can be readily used is a pre-assembled block made from a plurality of suitably configured ceramic plates stacked together. When such blocks are arranged in a near-annular array as required for a heat exchanger of annular configuration such blocks do not form a continuous circle of ceramic material. The gaps between the blocks introduce additional sealing problems.
SUMMARY OF THE INVENTION
An object of this invention is to provide a heat exchanger assembly which reduces the cost of fabrication, allows higher operating temperatures, and provides light-weight construction and efficient heat transfer.
Another object of this invention is to provide an annular heat exchanger assembly which can be readily constructed of pre-assembled ceramic blocks and in which the fluid streams can be positively sealed to provide better performance.
Another object of this invention is to provide a heat exchanger assembly which can accommodate a different coefficient of thermal expansion between the mounting means and the heat exchange matrix.
Another object of this invention is to provide a counterflow heat exchanger assembly which eliminates leakage between the counterflowing fluids during all operating temperatures.
Another object of this invention is to provide a counterflow heat exchanger assembly which can accommodate a thermal gradient between the low temperature end and the high temperature end of the heat exchanger while providing effective sealing at the inlet and exit flow ports.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and many of the attendant advantages of this invention will be better understood upon reading of the following detailed description when considered in conjunction with accompanying drawings, wherein similar elements of the several figures are identified by the same reference character, and wherein:
FIG. 1 is a partially exploded view of a ceramic member showing examples of the ceramic plates used to construct a heat exchange matrix and showing fragmentary sections of top and bottom clamping plates;
FIG. 1A is a side view of a ceramic plate;
FIG. 2 is a top view of the polygonal array of ceramic blocks;
FIG. 3 is a top view of a clamping plate showing an outline of the channel portion and clip assemblies;
FIG. 4 is a fragmentary elevation view looking radially inward in FIG. 3;
FIG. 5 is a fragmentary vertical sectional view along lines 5--5 of FIG. 3; and
FIG. 6 is a sectional view along line 6--6 of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a typical two stream heat exchanger, heat is exchanged between the fluids in the separate flow paths by the surfaces of the heat exchange matrix. The heat exchange matrix has four flow ports, including a first fluid inlet and exit and a second fluid inlet and exit. For the best performance of the heat exchanger, the flow ports should be isolated from each other so there is no leakage between fluids of different temperatures.
Member 10 of FIG. 1 illustrates one embodiment of a two-stream, stacked-plate heat exchange matrix which is readily fabricated at low cost. The matrix is constructed of individual ceramic plates 11 that are fused into the ceramic member or block 10. Using ceramic plates and a fusing process avoids the high fabrication cost associated with a metal plate construction. The assembled member 10 is substantially a hexagonal prism with four oblique faces 20, one for each of the flow ports 34-37 located therein. Top and bottom ridges 24 separate adjoining oblique faces.
As shown in FIG. 1A, each ceramic plate 11 has a profile with a rectangular body section 12 and top and bottom peaked sections 14. The peaked sections of each plate have a squared off or truncated portion at 16 that forms the ridge 24 in the assembled block.
The block 10 has internal flow passages that provide a matrix for the heat exchange between the two fluids. One embodiment of a plate that can be stacked to form flow passage is shown by the plate 11 of FIG. 1A. Each plate has one flat surface (not shown) and an opposite surface with channels 33 formed between raised ribs 32. The two boundary portions 26 along the edges of the plate 11 establish a general flow pattern and seal against an adjacent plate. The channels 33 are open-ended on the plate edges between the two boundary portions 26. Each plate in the stack is the mirror image of the adjacent plate. The channels in the assembled plates form flow passages through the ceramic member 10. The open ends of the channels from first fluid inlet flow ports 34, second fluid inlet flow ports 35, first fluid exit flow ports 36, and second fluid exit flow ports 37 on the center portion of the oblique faces 20 of the hexagonal prism. On each oblique face 20 there is a continuous flat sealing surface portion 22 surrounding the flow ports.
The thickness of the plate 11 has been exaggerated in the drawings for the sake of clarity. Likewise, the ribs 32 and channels 33 of FIG. 1A have been only schematically shown. In an actual plate, the ribs are very thin and close together to effect more flow channels and heat exchange. The boundary portions 26 and ribs 33 are oriented to produce the desired flow pattern, such as in the embodiment shown in FIG. 1A wherein each stream enters and exits at diagonally opposite edges. Other flow patterns are possible such as each stream entering and exiting at longitudinally opposite edges but on the same side of a plate.
A ceramic heat exchange matrix such as described above is readily fabricated in a hexagonal prism shape. A heat exchanger in an annular configuration is desired for many uses. In hot gas Stirling type engines for example, a circular combustion chamber is usually located at the center of the engine and is concentrically surrounded by an annular array of heater head tubes. The hot combustion gases flow through the heater head tubes and exchange heat to the sealed working fluid therein. To best utilize the remaining heat of the combustion gases, a counterflow preheater concentrically surrounds the annular heater head tubes. To approximate the annular configuration most desired, the ceramic members 10 are arranged in a regular polygon as shown in FIG. 2. However, trapezoidal gaps 38 are left between the members.
In order to mount the individual ceramic members 10 in a nearly annular array, top and bottom clamping plates (compression members) 40 and 41, respectively are provided, as illustrated in FIGS. 1 and 3. The clamping plates 40 and 41 are ring shaped and substantially flat at the inner and outer ring edges. A continuous channel 46 with a vee shape cross section is formed in the central portion of each clamping plate 40 and 41. The cross section of the channels 46 substantially conforms to the vee shape of the peaked sections 14 of the ceramic members 10. The cross section of the channel has a squared-off portion 48 to assist in fabrication. The channel 46 is of sufficient width and pitch such that two adjoining oblique faces 20 closely fit the vee shape cross section of the channel 46.
The channels 46 in the ring shaped clamping plates 40 and 41 have substantially the same polygon outline as the array of members 10, although the channel corners are rounded to assist in fabrication. The chord lines at the squared-off portion 48 of the channels are of sufficient length and straightness to accept the ceramic members 10.
The top clamping plate 40 has an annular inside flange 43 and an annular outside flange 45. The bottom plate 41 has an annular inside flange 42 and an annular outside flange 44. The flanges ae disposed at the inner and outer ring edges.
As illustrated in FIG. 5, a ceramic member 10 is held between top and bottom clamping plates 40 and 41. The oblique faces 20 of the ceramic member are adjacent the walls of the vee shaped channels 46. The ceramic members are seated in the channels 46 such that there is a small clearance 49 between the ridge 24 of the ceramic member and the squared off portion 48 of the channel.
The vee shaped channels 46 are provided with apertures 50 adjacent the flow ports 34-37 on the oblique faces of the ceramic members 10 to provide flow access to the flow parts. The area of the apertures 50 in the channel are slightly smaller than the area of the flow ports 34-37 on the oblique faces. Thus a portion of the walls of the channel 46 that surrounds the aperture interfaces with the sealing surface portion 22 that surrounds the flow ports 34-37 of the oblique faces. Gasket material 52 such as a ceramic fiber paper is placed at the interface of the metallic channel 46 and the sealing surface portion 22 of the oblique ceramic faces. The gasket material prevents leakage between the ceramic block 10 and the metallic mounting means 40 and 41.
As illustrated in FIGS. 4 and 6, top and bottom bolt clip assemblies 60 and 61 respectively, are adapted to fit the trapezoidal gaps 38 between the adjacent ceramic blocks in the array. The clip assemblies may be fabricated from a single metal sheet cut and bent to shape. Each assembly includes a horizontal ring segment 62 shaped to fit the gap 38. Attached perpendicular to the ring segments are wall portions 64 that extend longitudinally outward. The outward extending edge of the wall portions (away from the edge attached to the ring segments) have a peaked shape that conforms to the V cross-section of the channel 46. A perpendicular roof portion 66 is attached at each outward extending edge of the peaked shaped wall portion.
Two bolt clip assemblies are fitted into the gap 38 between blocks 10 such that the ring segments 62 are located a small distance longitudinally inward of the clamping plates 40 and 41. The wall portions 64 have a peaked shape which conforms to the profile of the ceramic member 10 and abuts the peaked portion of the ceramic member. The wall portions 64 serve to positively locate the ceramic members 10 in the array. Additionally, the wall portions 64 hold the gasket material 52 at the interface. The roof portion 66 abuts the walls of the channel 46 of the clamping plate and is attached thereto by welding or similar means.
A spring loaded bolt and nut assembly 70 holds the clamping plates together and holds the channels 40 attached thereto in compression against each pair of adjoining oblique faces 20. A bolt 72 is inserted through holes in the top and bottom ring segments 62. A spring 74 is placed over the threaded portion of the bolt to abut against the outside of one ring segment 62. A nut 76 or other restraining devices is screwed onto the threaded portion and is tightened to put the spring in compression. The ring segments 62 are pulled together and the attached clamping plates 40 and 41 hold the ceramic members 10 in compression. The tension on the bolt can be adjusted so that it is not relaxed by the difference of the thermal growth between the ceramic block and the bolt. Thus the ceramic members 10 will be held in compression by the clamping plates inspite of the thermal growth.
The difference coefficient of thermal expansion of the metallic clamping plates 40 and 41 and the ceramic member 10 will cause the clamping plates 40 and 41 to grow more than the ceramic against which it must seal. By making the ceramic member with a ridge 24, a small clearance space 49 is provided between the ceramic block 10 and the squared-off portion 48 of the clamping plate channel 46. This small clearance space allows the metal clamping plates 40 and 41 to grow on both sealing surfaces 22 of the oblique faces. The spring tension of the spring loaded bolt assemnbly 70 pulls the clamping plates 40 and 41 together against the gasket material 52 and the sealing surfaces 22 of the oblique faces of the ceramic member 10. The only relative motion then is some sliding along the oblique faces by the walls of the vee shape channel 46. The gasket material 52 at the interface of the metallic channel 46 and the ceramic member 10 continues to seal the flow ports 34-37 by deforming with the relative motion.
FIG. 5 illustrates one embodiment of the heat exchanger of this invention for use as a counterflow preheater in a Stirling type hot gas engine. Examples of such external combustion, hot gas engines are set forth in U.S. Pat. No. 3,940,934, issued Mar. 2, 1976, U.S. Pat. No. 4,261,173 issued Apr. 14, 1981, and U.S. Pat. No. 4,417,443 issued Nov. 29, 1983.
The annular heat exchanger assembly is supported in the engine by and in sealed air and exhaust fluid flow communication with annular manifold members which are attached to the clamping plates. An annular manifold common wall 102 is attached to the engine block (not shown) and extends generally upward. An annular air manifold ring 104 is attached to the manifold common wall 102 and extends radially inward and up from the common wall 102. Air manifold pipes 105 provides flow communication from an air blower (not shown). An annular exhaust manifold ring 108 is attached to the common wall 102 and extends radially outward and up from the common wall 102. Exhaust pipes 110 provide flow communication to the outside.
The bottom annular clamping plate 41 is positioned on an annular horizontal portion 112 of the annular manifold common wall 102. The squared-off portion 48 of the channel 46 sits on the horizontal portion 112 of the common wall and is welded into place. An annular bottom inside flange 42 of the clamping plate 41 is welded to the air manifold ring 104. An annular bottom outside flange 44 of the clamping plate 41 rests on the exhaust manifold ring 108.
The bottom bolt clip assemblies 61 are welded into the channel 46 of the bottom clamping plate 41 at the proper places. The ceramic members 10 are placed in the bottom channel in a near annular array such that the members 10 tightly fit between the bolt clip assemblies.
The top clamping plate 40 is prepared prior to being placed on top of the annular array. The bolts 72 are placed in the holes of the top bolt clip assemblies 60, before the clips 60 are positioned in the channel 46. The clip assemblies 60 are then welded in place in the channel. An annular heater transition ring 120 is welded to an annular top inside flange 43 of the top clamping plate 40. Annular attachment ring 124 is welded to the squared-off portion 48 of the top clamping plate 40.
The top clamping plate 40 is then positioned on top of the ceramic members 10 in the annular array. The threaded portion of the bolts 72 are placed through the holes in the bottom bolt clip assemblies 61 and the springs 74. The nuts 76 are attached outside the springs and tightened. As the top clamping plate 40 is placed on the ceramic members the other end 121 of the heater transition ring 120 fits into annular gasket joint 122 attached to the base of the heater head tubes 220. A band joint 126 secures the attachment ring 124 to a annular flange 128 connected to a circular combustor structure (not shown). Both joints provide annular sealing.
The heat shield 130 is then placed in position over the preheater, heater head and combustor assemblies. The top annular outside flange 45 of the top clamping plate 40 fits into a gasket joint 132 on the inside surface 133 of the heat shield. The base of the heat shield has a flange 134 that sits on manifold ring 108 and annular flange 44 of the clamping plate. Band ring 136 clamps the flanges together and holds the heat shield in place.
The support structure described for the heat exchanger assembly also defines four annular manifolds, each isolated from the other manifolds and in flow communication with the flow ports on only one oblique face of the ceramic heat exchanger assembly. Annular manifold common wall 102 and air manifold ring 104 define the air inlet manifold 202. The annular attachment ring 124 and the radial inside surface 133 of the heat shield 134 define a preheated air manifold 204. Annular heater transition ring 120 and annular attachment ring 124 define hot combustion gas manifold 206. Annular manifold common wall 102 and exhaust manifold ring 108 define exhaust manifold 208.
By sealing the four flow manifolds 202, 204, 206 and 208 on the longitudinal inside of the heat exchanger assembly to the continuous annular flanges 42-45 of the clamping plates, and on the longitudinal outside to the squared-off portion 48 of the annular channel 46, all four different-temperature flows have been isolated from each other and from the other engine environments without sealing the gaps 38 between the ceramic members 10. Therefore the growth of those gaps due to the relative thermal expansion does not affect the flow stream sealing.
The operation of the invention as a counterflow preheater for a hot gas Stirling type engine will be described with reference to FIG. 5. Ambient temperature air from a blower (not shown) is communicated through air pipe 106 to the air inlet manifold 202. The air 210 enters the ceramic heat exchange matrix through apertures 50 and air inlet flow ports 34. The air flows through the heat exchange matrix in air flow passages (not shown) and gains heat from the adjacent heated ceramic material. The preheated air 212 then exits the ceramic heat exchange matrix at air exit flow ports 36 and apertures 50 into the preheated air manifold 204. The preheated air flows through passage 216 to the combustion chamber (not shown).
After combustion in the combustion chamber, the hot combustion gas 218 flows between the annular array of heater head tubes 220 into the hot combustion gas manifold 206. The hot combustion gas enters the ceramic heat exchange matrix through the apertures 50 and the gas inlet flow ports 35. The hot gas flows through the heat exchange matrix in gas passages 224 that are adjacent to the air passages (not shown). The gas flow is in the opposite direction of the air flow. The hot gas in gas passages 224 gives up heat to the heat exchange matrix to heat the ambient temperature air in the air passages. The cooled combustion gas 226 then exits the ceramic heat exchange matrix at gas exit flow ports 37 and apertures 50 to the exhaust manifold 208. From the exhaust manifold the coolded gas exits the engine by way of exhaust pipes 210.
This invention can be readily constructed at a low cost since it utilizes preassembled ceramic heat exchange matrix members that are compatible with bench assembly. Additionally, the clamping plates and the bolt clip assemblies can be readily fabricated.
This invention also allows thermal flexibility in that the spring loaded bolts allow relative growth between the metallic clamping plates and the ceramic heat exchange matrix without loss of the sealing function at the interface between them.
This invention also allows for low mass since the material required other than the basic heat exchange matrix for mounting and supporting the heat exchanger matrix is a minimal amount of low-mass sheet metal.
Other changes, variations, modifications of the embodiment disclosed in this invention will become apparent to those skilled in the art in light of the teachings. It is therefore to be understood that any modifications, variations and changes are believed to come within the scope of the invention as defined by the appended claims: | An annular heat exchanger assembly includes a plurality of low thermal growth ceramic heat exchange members with inlet and exit flow ports on distinct faces. A mounting member locates each ceramic member in a near-annular array and seals the flow ports on the distinct faces into the separate flow paths of the heat exchanger. The mounting member adjusts for the temperature gradient in the assembly and the different coefficients of thermal expansion of the members of the assembly during all operating temperatures. | 5 |
TECHNICAL FIELD
[0001] The present invention pertains to devices, systems, and methods for planting seeds, as well as to methods of manufacturing such devices and systems. More particularly, the present invention is directed to: a) devices comprising a storage container, an air propulsion apparatus, and a hollow horizontal member and a plurality of hollow vertical members; b) systems comprising a storage container, an air propulsion apparatus, and a hollow horizontal member and a plurality of hollow vertical members; and c) methods of manufacturing or using such devices and systems.
BACKGROUND OF THE INVENTION
[0002] In rural areas of the developing world, many people remain mired in poverty and dependent upon small subsistence level farms as their only source of food. These subsistence farmers, reliant on their harvests to feed themselves and their families, lack the agricultural equipment needed to increase the productivity of their harvests. The low productivity of these subsistence farms means that farmers are unable to grow any surplus of food that could be sold at the market place, preventing these farmers from earning the income that would allow them to invest in their farms, purchase healthcare and education for their families, and progress out of poverty towards the middle class.
[0003] Cambodia, one of the poorest countries in Asia, presents a vivid illustration of the plight faced by Third World subsistence farmers. Plagued by decades of conflict, nearly eighty percent of Cambodia's population lives in rural areas, with many relying on farming as their only source of food and income. Rice is the primary crop of Cambodian farmers. To ensure the optimal spacing of the rice plants and to facilitate weeding and the application of fertilizers, herbicides, or insecticide, rice is grown in rows, which results in greater crop yields for the rice than growing the crop in other patterns.
[0004] In a traditional Cambodian method for rice-farming, farmers plant rice in one or more smaller plots for a certain period of time, and then transplant the seedlings by hand to the main field for maturation once those seedlings have grown to a sufficient size. In contrast, in more developed countries where farming is more machine-intensive and industrialized, automated equipment capable of mechanically planting and cultivating rice in rows is commonly utilized, replacing the traditional hand-transplantation techniques used by rural farmers in Cambodia and other Southeast Asian countries.
[0005] Unlike the more industrialized farming sectors in other nations, the relative lack of income and resources of many Cambodian farmers means that automated equipment for planting rice crops is largely unavailable to these farmers. This means that these farmers must employ human labor to plant their rice crops using the traditional Cambodian method. This method is very labor intensive, as the traditional method can take up to fifty days for a single farmer to plant a one-hectare field of rice. And recent years have seen a migration of working aged men and women from rural Cambodian farming communities to more urban locales in order to work in garment factories or construction in Cambodia or in other Southeast Asian countries.
[0006] This migration has reduced the amount of labor available to these Cambodian communities, forcing farmers in Cambodia to either plant fewer fields of rice or use less efficient methods for planting rice (such as spreading rice seeds by hand on dry ground, which results in sub-optimal arrangements of the rice crop and many of the seeds being eaten by animals or failing to sprout). The resulting reduction in crop yields negatively impacts Cambodian farm families, who already struggle to satisfy their nutritional needs (and to meet their needs for adequate healthcare and education).
[0007] To solve these challenges faced by Cambodian farmers, as well as farmers in other Southeast Asian rice-planting countries, there remains a need for the development and distribution of devices and techniques that would enable these farmers to plant rows of crops while reducing the time, labor, costs, and overall resources needed to plant their crops. Such devices and techniques would allow these farmers to employ their labor more efficiently and waste less seed, water, and fertilizer in the planting process, not only improving crop yields, but also providing an opportunity for these farmers to allocate more of their time elsewhere (for example, obtaining education). These devices and techniques would ultimately aid in raising the income of farmers, helping to lift them and their families out of poverty.
[0008] While devices for planting rice seeds exist, no known existing designs are sufficient to meet the above-mentioned needs of farmers in Cambodia or other Southeast Asian nations. While sophisticated devices for planting rice seed exist and are used in more industrialized nations, such mechanized devices are too expensive and complex for small-scale farmers. Furthermore, for example, Cambodia's manufacturing sector is relatively less-developed in comparison with some neighboring countries. Therefore, for a device for planting rice to be truly accessible to Cambodian farmers (or rural farmers in other Southeast Asian countries) at a reasonable cost, that device must be capable of being manufactured locally, using readily available materials and manufacturing processes.
[0009] Simpler devices, such as broadcast planters that use air power to spray seeds, are inefficient, blowing rice seed in uncontrolled patterns and lacking the concentrated velocity necessary to embed the rice seed into the soil. If not embedded into the soil, the rice remains on top of the soil, and is readily eaten by animals or blown away by wind or washed away by rains. Drum seeders, which are rolled on the ground and drop seed out of holes, also cannot embed the dropped rice seeds into soil, similarly leaving the rice susceptible to being eaten or swept away by wind or rain. Other attempts at developing a suitable device for planting rice seeds suffered from repeated jamming problems, causing these attempts to fail.
[0010] As discussed above, existing devices and techniques for planting rice seed suffer from deficiencies: failing to effectively plant rice seed in rows without unduly wasting seed, labor, and other resources. As a result, there remains a need for devices and techniques for planting rice seeds that do not suffer from the drawbacks shared by these existing devices and methods.
SUMMARY OF THE INVENTION
[0011] The present invention is directed, in certain embodiments, to devices for planting seeds, the devices comprising a storage container, an air propulsion apparatus connected to the storage container, a first hollow member, a hollow horizontal member connected to the first hollow member, and a plurality of hollow vertical members connected to a bottom of the hollow horizontal member. In certain embodiments, the storage container contains seeds. In certain further embodiments, the storage container is capable of holding at least 10 kilograms of seeds. In still further embodiments, the storage container is capable of holding at least 20 kilograms of seeds.
[0012] In certain embodiments, the air propulsion apparatus is connected to the hollow horizontal member via the first hollow member.
[0013] In certain embodiments, the first hollow member is a hose.
[0014] In certain embodiments, the air propulsion apparatus is a broadcast planter. In certain further embodiments, the broadcast planter is a gasoline-powered broadcast planter. In other further embodiments, the broadcast planter is an electric-powered broadcast planter. In still further embodiments, the electric-powered broadcast planter comprises a battery.
[0015] In certain embodiments, the hollow horizontal member comprises a plurality of pipes and flow reducers connected by T-connectors. In certain further embodiments, the device further comprises elbow connectors connected to a first and a second end of the hollow horizontal member, and a flow reducer connected to each of the elbow connectors. In still further embodiments, the plurality of pipes, flow reducers, T-connectors, and elbow connectors are comprised of PVC.
[0016] In certain embodiments, a diameter of the hollow horizontal member at a center of the hollow horizontal member is greater than both: a) a diameter of the hollow horizontal member at a first end of the hollow horizontal member; and b) a diameter of the hollow horizontal member at a second end of the hollow horizontal member. In certain further embodiments, the diameter of the hollow horizontal member at the first end is equal to the diameter of the hollow horizontal member at the second end.
[0017] In certain embodiments, a diameter of the hollow horizontal member at a center of the hollow horizontal member is equal to both: a) a diameter of the hollow horizontal member at a first end of the hollow horizontal member; and b) a diameter of the hollow horizontal member at a second end of the hollow horizontal member.
[0018] In certain embodiments, the first hollow member is connected to the hollow horizontal member by a T-connector at a center of the hollow horizontal member. In certain further embodiments, the first hollow member is connected to the hollow horizontal member at a top of the hollow horizontal member. In certain embodiments, the T-connector comprises a protrusion that divides a perpendicular inlet of the T-connector in half. In certain further embodiments, the protrusion comprises a sheet of material.
[0019] In certain embodiments, each of the plurality of hollow vertical members is connected to the bottom of the hollow horizontal member by either a T-connector or an elbow connector. In certain further embodiments, each of the plurality of hollow vertical members comprises a PVC pipe.
[0020] In certain embodiments, a diameter of a first end of each of the plurality of hollow vertical members is larger than a diameter of a second end of each of the plurality of hollow vertical members. In certain further embodiments, the diameter of the first end of each of the plurality of hollow vertical members is equal to or lesser than a diameter of a midpoint of each of the plurality of hollow vertical members. In still further embodiments, the first end of each of the plurality of hollow vertical members is located within the T-connector or elbow connector connecting the hollow vertical member to the hollow horizontal member.
[0021] In certain embodiments, the first end of the at least one of the plurality of hollow vertical members comprises a baffle. In certain further embodiments, the first end of the at least one hollow vertical member comprises a notch. In still further embodiments, a diameter of the first end of the at least one hollow vertical member above the notch is smaller than a diameter of the first end of the at least one hollow vertical member below the notch. In even further embodiments, the hollow horizontal member is engaged with the notch in the first end of the at least one hollow vertical member.
[0022] In certain embodiments, the second end of each of the plurality of hollow vertical members comprises a nozzle. In further embodiments, the second end of each of the plurality of hollow vertical members further comprises a nozzle cover. In still further embodiments, the nozzle cover comprises a flexible hose.
[0023] In certain embodiments, the plurality of hollow vertical members comprises between 4 hollow vertical members and 40 hollow vertical members. In certain further embodiments, the plurality of hollow vertical members comprises between 10 hollow vertical members and 30 hollow vertical members. In still further embodiments, the plurality of hollow vertical members comprises between 14 hollow vertical members and 18 hollow vertical members. In other further embodiments, the plurality of vertical members comprises between 22 hollow vertical members and 26 hollow vertical members.
[0024] In certain embodiments, the plurality of hollow vertical members are evenly spaced along the hollow horizontal member.
[0025] The present invention is directed, in certain embodiments, to systems for planting seeds, the systems comprising a storage container, an air propulsion apparatus connected to the storage container, a first hollow member, a hollow horizontal member connected to the first hollow member, and a plurality of hollow vertical members connected to a bottom of the hollow horizontal member.
[0026] In certain embodiments, at least one of the storage container, the air propulsion apparatus, the first hollow member, the hollow horizontal member, and the plurality of hollow vertical members is mounted on a movable support. In certain further embodiments, the movable support comprises a cart. In still further embodiments, the cart comprises wheels or skis. In even further embodiments, the cart is human-powered, animal-powered, or machine-powered. In certain embodiments, the moveable support is covered with a rust-resistant coating.
[0027] In certain embodiments, at least one of the storage container, the air propulsion apparatus, the first hollow member, the hollow horizontal member, and the plurality of hollow vertical members is carried by a human user.
[0028] The present invention is directed, in certain embodiments, to methods for planting seeds, the methods comprising the steps of filling a storage container with seeds, emptying the seeds from the storage container into an air propulsion apparatus, and propelling the seeds through the air propulsion apparatus, through a first hollow member, through a horizontal hollow member, through a plurality of vertical hollow members, and into the ground.
[0029] In certain embodiments, the methods comprise the step of soaking the seeds in water for a period of time and then drying the seeds before filling the storage container with the seeds.
[0030] In certain embodiments, a first end of at least one of the plurality of vertical hollow members comprises a baffle located inside the hollow horizontal member, and an equal volume of seeds is propelled into each of the plurality of vertical horizontal members. In certain further embodiments, a second end of each of the plurality of vertical hollow members comprises a nozzle, and the velocity of the seeds exiting the nozzle of the vertical hollow member is greater than or equal to the velocity of the seeds entering the first end of the vertical hollow member.
[0031] In certain embodiments, filling the storage container with seeds comprises filling the storage container with both seeds and fertilizer. In certain further embodiments, the fertilizer mixes with the seeds to create a mixture of seeds and fertilizer, and the mixture empties from the storage container into the air propulsion apparatus, which propels the mixture through the air propulsion apparatus, through the first hollow member, through the horizontal hollow member, and through the plurality of vertical hollow members and into the ground.
[0032] The present invention is directed, in certain embodiments, to methods of manufacturing devices for planting seeds, the methods comprising the steps of thermal forming a T-connector from PVC, thermal forming a sheet of PVC, inserting the sheet of PVC into the T-connector to form a flow divider, resizing a plurality of PVC pipes, flow reducers, T-connectors, and elbow connectors and gluing the plurality of PVC pipes, flow reducers, T-connectors, and elbow connectors together to form a hollow horizontal member, connecting a storage container to a first hollow member via an air propulsion apparatus, connecting the hollow horizontal member to the first hollow member via the flow divider, thermal die forming a first end of at least one of a plurality of vertical hollow members to form a baffle, thermal die forming a second end of each of the plurality of vertical hollow members to form a nozzle, and inserting the first end of each of the plurality of vertical hollow members into a bottom of the hollow horizontal member.
[0033] In certain embodiments, the step of resizing the plurality of PVC pipes, flow reducers, T-connectors, and elbow connectors comprises cutting and grinding the plurality of PVC pipes, flow reducers, T-connectors, and elbow connectors.
[0034] In certain embodiments, the methods further comprise the step of covering the horizontal hollow member and the plurality of vertical hollow members with a UV-resistant coating.
[0035] In certain embodiments, the methods further comprise the step of enclosing the hollow horizontal member with a PVC pipe with an inner diameter less than or equal to an outer diameter of the hollow horizontal member. In certain further embodiments, enclosing the hollow horizontal member with the PVC pipe comprises cutting a slit in a bottom of the PVC pipe and stretching the PVC pipe to enclose the hollow horizontal member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 depicts a perspective view of an exemplary device for planting seeds, the device comprising a storage container, an air propulsion apparatus, and a first hollow member, hollow horizontal member, and plurality of hollow vertical members.
[0037] FIG. 2 depicts a perspective view of the device for planting seeds of FIG. 1 , the device being mounted on a cart that comprises wheels.
[0038] FIG. 3 depicts a perspective view of the device for planting seeds of FIG. 1 , the device being mounted on a cart that comprises skis.
[0039] FIG. 4A depicts a perspective view of the hollow horizontal member and plurality of hollow vertical members of FIG. 1 .
[0040] FIG. 4B depicts a front view of the hollow horizontal member and plurality of hollow vertical members of FIG. 1 .
[0041] FIG. 4C depicts a side view of the hollow horizontal member and plurality of hollow vertical members of FIG. 1 .
[0042] FIG. 4D depicts a top view of the hollow horizontal member and plurality of hollow vertical members of FIG. 1 .
[0043] FIG. 4E depicts a bottom view of the hollow horizontal member and plurality of hollow vertical members of FIG. 1 .
[0044] FIG. 5 depicts an interior cross-sectional view of the hollow horizontal member and the plurality of hollow vertical members of FIGS. 4A-4E .
[0045] FIG. 6A depicts a perspective view of one of the hollow vertical members depicted in FIGS. 4A-4E .
[0046] FIG. 6B depicts a front view of one of the hollow vertical members depicted in FIGS. 4A-4E .
[0047] FIG. 6C depicts a side view of one of the hollow vertical members depicted in FIGS. 4A-4E .
[0048] FIG. 6D depicts a top view of one of the hollow vertical members depicted in FIGS. 4A-4E .
[0049] FIG. 6E depicts a bottom view of one of the hollow vertical members depicted in FIGS. 4A-4E .
[0050] FIG. 7 depicts a perspective view of the exemplary hollow vertical member depicted in FIGS. 6A-6E , the hollow vertical member further comprising a nozzle cover.
[0051] FIG. 8 depicts a perspective view of an exemplary device for planting seeds that comprises a frame for mounting and supporting a plurality of hollow vertical members, handles, and a pair of skis mounted to the frame.
DETAILED DESCRIPTION OF THE INVENTION
[0052] The present invention is directed to air-powered devices for planting seeds, systems incorporating those air-powered devices, as well as to methods of operating and manufacturing such devices and systems for planting seeds. One embodiment of the invention is a device for planting seeds, comprising a storage container, an air propulsion apparatus, a first hollow member, a hollow horizontal member, and a plurality of hollow vertical members. The storage container is connected to the air propulsion apparatus, which uses air propulsion to propel seeds throughout the hollow members of the device and into the ground to be planted.
[0053] A second embodiment of the invention is a system for planting seeds. The system incorporates the air-powered device, and at least a portion of the device is mounted on a movable support or carried by a human user.
[0054] A third embodiment of the invention is a method of planting seeds, comprising filling the storage container with seeds, emptying the seeds from the storage container into the air propulsion apparatus, and using air power from the air propulsion apparatus to propel seeds throughout the hollow members of the device and into the ground to be planted.
[0055] A fourth embodiment of the invention is a method for manufacturing the air-powered device for planting seeds, comprising thermal forming a flow divider from PVC, resizing and gluing together a plurality of PVC pipes, flow reducers, T-connectors, and elbow connectors to form a hollow horizontal member, thermal die forming a plurality of vertical hollow members, and connecting together the storage container, air propulsion apparatus, hollow horizontal member, and the plurality of vertical hollow members to prepare the air-powered device for planting seeds.
[0056] FIG. 1 depicts an exemplary embodiment of a device 100 for planting seeds, in accordance with the present invention. The device 100 comprises a storage container 102 capable of storing seeds and then releasing those seeds into the device 100 during the planting process. In these embodiments, the storage container 102 holds seeds, fertilizer, or a mixture of both seed and fertilizer. In some embodiments, the storage container 102 contains rice seeds. However, the type of seed stored in the storage container 102 is not limited to rice seeds—the storage container 102 may instead contain (for example) seed for corn, mung beans, soy beans, or other types of grains or legumes.
[0057] In embodiments, the storage container 102 is comprised of plastic. However, the storage container 102 may be composed of other materials as well: for example, metals such as steel and/or aluminum, other polymers (such as PVC), or even wood. In certain embodiments of the invention, such as the storage container 102 depicted in the device 100 of FIG. 1 , the storage container 102 is a hopper 102 that is integrated into an air propulsion device 104 , such as a hopper 102 that feeds into a broadcast planter 104 . In other embodiments, however, the storage container 102 may be separate from the air propulsion device. In these various embodiments, the storage container 102 may be a hopper, a tub, a basket, or similar storage containers 102 . The storage container 102 may be cylindrical, square, rectangular, or any other shape suitable for holding seed, fertilizer, and other materials used in the planting process.
[0058] In embodiments of the present invention, the storage container 102 has sufficient size and strength to be capable of holding at least 10 kilograms of seeds and/or fertilizer. In some of these embodiments of the present invention, the storage container 102 possesses sufficient size and strength to be capable of holding at least 10 kilograms of seeds (and/or fertilizer). Further, in some of these various embodiments, the storage container 102 is of sufficient size and strength to house at least 15, at least 20, at least 25, or at least 30 kilograms of seeds (and/or fertilizer). The storage containers 102 of the present invention will be capable of holding a varying amount of seeds depending upon the dimensions of the storage container 102 , the type of seeds (and their size) placed in the storage container 102 , whether the seeds were enlarged by soaking them overnight in water before planting, and other considerations.
[0059] As discussed above, the seeds in storage container 102 may have been soaked, and then dried, before the storage container 102 was filled with those seeds. Soaking the seeds enables the seeds to more efficiently embed in the ground and to germinate at a faster rate. If the seeds are not soaked before planting, they may be more susceptible to being blown away in strong winds, or being eaten by animals, before they embed in the ground and germinate.
[0060] In addition to storage container 102 , the device 100 for planting seeds in a field comprises an air propulsion apparatus 104 connected to the storage container 102 . In preferred embodiments of the present invention, the device 100 for planting seeds in a field comprises an air propulsion apparatus 104 . In certain preferred embodiments of the invention, the air propulsion apparatus 104 is a broadcast planter 104 (also known as a broadcast seeder, a seed blower, or a broadcast seed blower). The broadcast planter 104 is an agricultural device commonly used to spread seed, fertilizer, and other substances as well (such as, for example, mulch, lime, salt, or other granular products). Suitable fertilizers for use with broadcast planter 104 include, for example, NPK 18-46-0, NPK 15-15-15, NPK 16-20, or NPK 46. The broadcast planter 104 operates by feeding seeds or fertilizer from a hopper 102 at a controlled rate into an air-powered seed blower, which projects the seeds out of the seed blower by spraying them using air power. In some embodiments of the present invention, the seed blower of the broadcast planter 104 is gasoline- or diesel-powered. However, in other embodiments of the invention, the seed blower of the broadcast planter 104 is electric-powered, and can comprise, for example, a rechargeable battery which may be recharged from electricity from solar power, wind power, or other renewable energy sources. Instead of a broadcast planter 104 , however, the air propulsion apparatus 104 could also comprise, for example, a leaf blower.
[0061] In preferred embodiments of the invention, the device 100 for planting seeds comprises a hollow member 106 connected to the air propulsion apparatus 104 . In these embodiments, the seeds (and/or fertilizer, or mulch, or other granular material) are propelled into (and through) the hollow member 106 by the air propulsion apparatus 104 , and the hollow member 106 serves to connect the seed storage container 102 and air propulsion apparatus 104 to the rest of the device 100 for planting seeds.
[0062] In certain embodiments, the hollow member 106 attached to the air propulsion apparatus 104 may be a flexible hollow member 106 , such as the hose 106 depicted in FIG. 1 . In these embodiments, the hollow member 106 may comprise a hose 106 (either a corrugated or non-corrugated hose), composed of (for example) a rubber or a flexible polymer. In other embodiments, however, the hollow member 106 attached to the air propulsion apparatus 104 may be made of a rigid material, such as (for example) PVC pipe, aluminum, steel, or other suitable materials. In these embodiments, the hollow member 106 may be a rigid cylindrical tube, for example, instead of a flexible hose.
[0063] As shown in the device 100 depicted in FIG. 1 , while one end of flexible hollow member 106 is connected to air propulsion apparatus 104 , the other end of flexible hollow member 106 is connected to a horizontal member 110 , into which the seeds from storage container 102 are propelled from broadcast planter 104 and through flexible hollow member 106 into horizontal member 110 . The device 100 also comprises a plurality of vertical members 120 , which are each attached to a bottom of horizontal member 110 . The seeds propelled into hollow horizontal member 110 are propelled through the hollow horizontal member 110 towards the ends of hollow horizontal member 110 and into the plurality of hollow vertical members 120 , and from the ends of the vertical members 120 into the ground for planting.
[0064] In various embodiments of the device 100 depicted in FIG. 1 , the number of vertical members 120 that are attached to hollow horizontal member 110 may vary, based on, for example, the size of hollow horizontal member 110 , and/or the type (and power) of the air propulsion apparatus 104 . In some preferred embodiments, the device 100 comprises an equal number of vertical members 120 on each side of the point where flexible hollow member 106 connects to hollow horizontal member 110 , the distances between each pair of adjacent vertical members 120 are constant and equal, and the device 100 is configured so that an equal amount of seed is propelled through each individual one of the plurality of vertical members 120 . In these embodiments, the device 100 will have an even number of vertical members 120 . An equal amount of seed being propelled through each one of the plurality of vertical members 120 allows a farmer to plant even, equidistantly spaced rows of crops, which each row containing a relatively equal number of plants. In other embodiments, however, the number of vertical members 120 on each side of the point where flexible hollow member 106 connects to hollow horizontal member 110 may be different.
[0065] In various embodiments of the present invention, the plurality of hollow vertical members 120 can comprise between 4 and 40 hollow vertical members, between 10 and 30 hollow vertical members, between 22 and 26 hollow members, or between 14 and 18 hollow vertical members.
[0066] The relative amounts of seed propelled through each of the plurality of vertical members 120 can be tested by running the device 100 in an experimental environment, and measuring the amount of seed that is propelled through each of the plurality of vertical members 120 by placing a bag or sock over the end of each of the plurality of vertical members 120 , and then comparing the relative amount of seed that has been collected in each bag or sock.
[0067] In the exemplary embodiment depicted in FIG. 1 , the air propulsion apparatus 104 can be carried by a user of the device 100 , for example by mounting the storage container 102 and air propulsion apparatus 104 on a backpack (not shown) or other equipment that can be carried by a user. In these embodiments, one user may carry the storage container 102 and air propulsion apparatus 104 around a field using a backpack or similar equipment, and one or more other users may aid in moving the horizontal member 110 and vertical members 120 around the field during the planting process.
[0068] FIG. 2 depicts a different embodiment of a system 200 for planting seeds, in which the storage container 102 , air propulsion apparatus 104 , horizontal member 110 , and vertical members 120 are mounted on a moveable support 210 . In this exemplary system 200 , the moveable support 210 is a cart 210 with wheels 220 —however, the moveable support could take other forms as well (for example, a sled). In system 200 , the cart 210 helps bear the weight of the storage container 102 , air propulsion apparatus 104 , horizontal member 110 , and vertical members 120 , and wheels 220 aid a user of system 200 of moving the system 200 around a field to plant seeds using system 200 . The cart 210 and wheels 220 may be made of metals (such as iron, steel, stainless steel, or aluminum), or other materials such as PVC, bamboo, or wood, (or, in the case of the wheels, rubber) and may be coated with one or more substances that protect the cart 210 from rust and/or degradation from ultraviolet (UV) rays (such as rust- and/or UV-resistant paint(s)). In some embodiments, part of the system 200 may be mounted on cart 210 and wheeled (or otherwise moved) by a first user, and a separate part of the system 200 may be carried around the field separately by one or more other users. In other exemplary embodiments, however, the cart 210 may be towed by an animal, or may have a motor or other propulsion device capable of mechanically propelling cart 210 with little or no effort from a user.
[0069] The wheels 220 of cart 210 are useful in moving system 200 around a field in which the ground is relatively firm. However, if the field is inundated with water or relatively muddy (as rice paddies commonly are), the wheels 220 of cart 210 may become bogged down in mud or water, making it difficult to move system 200 around the field. FIG. 3 depicts a different exemplary system 300 , featuring a cart 310 with two skis 320 upon which the cart 310 is mounted. The skis 320 are preferred in wetter environments, such as an inundated rice paddy, in which it is easier for the system 300 to slide over the ground of a field instead of using rolling wheels that can become bogged down in the wet ground, such as the wheels 220 of the cart 210 shown in FIG. 2 . The skis 320 of system 300 may be made of different materials, for example a rigid plastic (such as PVC plastic) or other polymers, a metal (such as steel or aluminum), or composite materials.
[0070] FIGS. 4A-E depicts an exemplary embodiment of the “piping” system 400 that comprises both the hollow horizontal member and vertical members of a device for planting seeds. In this exemplary embodiment, the piping system 400 attaches to a flexible hollow member (such as hollow member 106 depicted in FIG. 1 ) via a T-connector 420 . The T-connector 420 receives seeds from an air propulsion device (not shown), such as a broadcast planter, and distributes the seeds evenly to each side of the T-connector 420 by utilizing a “flow divider” inside the T-connector 420 which splits the flow of seeds. The flow divider (not shown in this view) may be a flat, planar sheet of material, which splits the volume inside the perpendicular inlet of the T-connector 420 in half. The T-connector 420 may be positioned so that the flexible hollow member is attached to the top of the hollow horizontal member, to the side of the hollow horizontal member, or at an angle in-between.
[0071] In exemplary preferred embodiments, T-connector 420 and the flow divider inside are both comprised of polyvinyl chloride (PVC) plastic. The T-connector 420 and the flow divider may be manufactured by thermal forming the T-connector 420 from PVC, thermal forming a sheet of PVC, and then inserting the thermal-formed sheet of PVC into the perpendicular inlet of the T-connector 420 to form a flow divider within that perpendicular inlet.
[0072] The hollow horizontal member of piping system 400 is comprised of a number of T-connectors 440 and flow reducers 460 that connect segments of pipe 430 to form the hollow horizontal member. The T-connectors 440 connect both the segments of pipe 430 with each other, and also connect the vertical members 410 to the hollow horizontal member. In the exemplary preferred embodiment 400 depicted in FIGS. 4A-E , the segments of pipe 430 decrease in diameter along the length of hollow horizontal member away from T-connector 420 towards the ends of the hollow horizontal member, because the amount of seed flowing through the segments of pipe 430 decreases at increasing distances from the receiving T-connector 420 as seed is directed into each of vertical members 410 . The flow reducers 460 connect segments of pipe 430 of different diameters, allowing the hollow horizontal member to decrease in diameter so that a diameter of the hollow horizontal member is greater at the T-connector 420 than either of the two ends of the hollow horizontal member, which each comprise elbow connectors 450 which connect the end vertical members 410 to the hollow horizontal member.
[0073] The segments of pipe 430 , the T-connectors 420 and 440 , and the flow reducers 460 may be comprised of varying materials, such as metals, polymers, or composites. However, in exemplary preferred embodiments of the piping system 400 , the segments of pipe 430 , the T-connectors 420 and 440 , and the flow reducers 460 are all comprised of polyvinyl chloride (PVC) plastic. In exemplary embodiments, the segments of pipe 430 , the T-connectors 420 and 440 , and the flow reducers 460 are resized and then connected together to form the horizontal hollow member of system 400 . Resizing includes, for example, cutting, grinding, and using other machining techniques to resize the segments of pipe 430 , the T-connectors 420 and 440 , and the flow reducers 460 . After the segments of pipe 430 , the T-connectors 420 and 440 , and the flow reducers 460 are connected together, they can be glued together to form the hollow horizontal member.
[0074] While the hollow horizontal member of exemplary embodiment 400 is comprised of a plurality of interconnected segments of pipe 430 , T-connectors 420 and 440 , and flow reducers 460 as described above, in other embodiments of the invention, the hollow horizontal member may comprise a single hollow horizontal component (not shown). In these embodiments, the single hollow horizontal component may be a tube, pipe, or cylinder. In certain embodiments, the single hollow horizontal component has a constant diameter along its length. In other embodiments, the ends of the hollow horizontal component each have a smaller diameter than the center of the hollow horizontal component.
[0075] In the exemplary embodiment 400 depicted in FIGS. 4A-E , the piping 400 comprises sixteen vertical members 410 , with eight vertical members 410 evenly spaced along each side of the T-connector 420 . In this exemplary embodiment, an equal amount of seed is directed into each of the eight vertical members 410 . In exemplary piping system 400 , of the vertical members 410 decreases in diameter from the top of the vertical member 410 to the bottom of the vertical member 410 , forming a nozzle 415 at the end of vertical member 410 . The nozzle 415 increases the velocity of seeds being propelled from vertical member 410 (as the cross-sectional area of nozzle 415 is smaller in comparison to the upper part of vertical member 410 ), and also focuses the area in which seeds are propelled from vertical member 410 , allowing seeds to effectively embed into the ground of a field in neat, equidistant rows. In some embodiments, the diameter of the vertical member 410 may remain constant along the majority of the vertical length of vertical member 410 , only decreasing at the portion of vertical member 410 that comprises nozzle 415 . In other embodiments, the diameter of the vertical member 410 may vary along the entire vertical length of vertical member 410 , gradually growing smaller as it gets closer to nozzle 415 .
[0076] In preferred embodiments of the invention, vertical member 410 , like the segments of pipe 430 , the T-connectors 420 and 440 , and the flow reducers 460 , is comprised of polyvinyl chloride (PVC) plastic. Nozzle 415 can be manufactured by thermal die forming an end of vertical member 410 into nozzle 415 . The vertical members 410 can then be inserted and glued into the perpendicular inlets of T-connectors 440 to connect the vertical members 410 to the piping system 400 .
[0077] In embodiments, in which vertical members 410 , segments of pipe 430 , the T-connectors 420 and 440 , and flow reducers 460 are comprised of PVC, the PVC piping can be covered or coated with a UV-resistant paint or other coating which helps those PVC pieces resist degradation from ultraviolet radiation, prolonging the life of piping system 400 .
[0078] FIG. 5 is a cross-sectional view of exemplary piping system 500 , which illustrates the flow of seed (and/or fertilizer) through system 500 . As seed enters the system 500 at the perpendicular inlet of T-connector 520 , flow divider 510 acts to split the flow of seed in half, directing each half of the seed flow to each side of flow divider 510 and into interior segments of piping 505 . Each of the interior segments of piping 505 is connected to each other and to interior vertical members 530 a via T-connectors 508 , and the end segments of piping 515 are connected to end vertical members 530 b via elbow connectors 550 . In this exemplary embodiment 500 , the interior segments of piping 505 have a larger diameter than the end segments of piping 515 . Seed exits the vertical members 530 a and 530 b at relatively higher velocity from nozzle 535 , as depicted by flow arrows 538 .
[0079] As seed is propelled horizontally away from T-connector 520 and flow divider 510 , it is caught by the cup-shaped baffles 545 that are connected to the top of the interior vertical tubes 530 a . Each baffle 545 has a closed top, and is shaped as a cup or closed half-pipe which “catches” and re-directs seed (and/or fertilizer) away from the horizontal flow into interior vertical tubes 530 a , as illustrated by flow arrows 533 a . In preferred embodiments, the baffles 545 are designed so that each interior vertical member 530 a catches and receives an approximately equivalent amount of seed. Each of the baffles 545 is connected to a respective interior vertical tube 530 a by connector 540 .
[0080] As the flow of seed reaches the end piping segments 515 , all of the seed remaining in the flow is directed into end vertical members 530 b , as illustrated by flow arrows 533 b . Thus, there is no need for end vertical members 530 b to be connected to baffles that catch and redirect only a portion of the seed in the flow.
[0081] By catching and redirecting approximately equal amounts of seed (and/or fertilizer), the baffles 545 ensure that approximately equal amounts of crops are planted in each row, and help prevent the device from jamming from one or more vertical tubes 530 a or 530 b having seed propelled into it at too great a rate.
[0082] The baffles 545 may be manufactured from different materials, but in exemplary preferred embodiments, the baffles 545 are comprised of PVC plastic. In these embodiments, the baffles 545 are manufactured by thermal die forming, in which the PVC is heated and then formed/folded around a metal or wooden die having the desired cup-like, closed half-pipe shape for the baffle 545 .
[0083] FIGS. 6A-E depict an exemplary interior vertical pipe 530 a having a nozzle 535 for propelling seed (and/or fertilizer) and attached to a baffle 545 via connector 520 . The bottom portion 540 of baffle 545 connects the baffle 545 to connector 520 , allowing the cup-shaped baffle 545 to catch and redirect seed into the vertical member 530 a . As depicted in FIGS. 6A-E , the baffle 545 may decrease in diameter further away from the bottom portion 540 of baffle 545 , and may comprise a notch that can attach to an edge of the horizontal piping.
[0084] FIG. 7 depicts an exemplary embodiment of a vertical member 530 a in which a nozzle cover 710 has been attached to nozzle 535 . In this exemplary embodiment, the nozzle cover 710 comprises a plurality of flexible strands 710 a - c which aid in planting seeds on ground that is relatively dry and firm. When propelled from the nozzle 535 , the seeds may bounce off of the firm ground, away from nozzle 535 . Nozzle cover 710 helps catch and redirect seeds, helping the seeds to maintain their position in relatively orderly rows in the field. The exemplary embodiment 710 depicted in FIG. 7 is comprised of strands of flexible rubber hose 710 a - c . However, nozzle covers 710 may take varying forms and be composed of varying materials, including but not limited to a hose, skirt, curtain, or cone that helps direct seed from nozzle 535 .
[0085] The following Examples are only illustrative. It will be readily seen by one of ordinary skill in the art that the present invention fulfills the objectives set forth above. After reading the foregoing specification, one of ordinary skill will be able to effect various changes, substitutions of equivalents, and various other embodiments of the invention as broadly disclosed therein. It is therefore intended that the protection granted herein be limited only by the definition contained in the appended claims and equivalents thereof.
Examples
[0086] FIG. 8 depicts an exemplary embodiment of a device 800 for planting seed. PVC T-connector 420 of device 800 can be attached, via a hose or other connector (not shown) to a broadcast planter or similar device for propelling seed and/or fertilizer. The T-connector 420 is attached to a set of horizontal PVC piping (not shown), which is enclosed by a piece of PVC pipe 810 . The PVC pipe 810 comprises a slit along its length, which allows the PVC pipe 810 to be stretched to enclose and fit snugly around the horizontal PVC piping of device 800 .
[0087] The exemplary device 800 features 12 vertical members 410 , each comprised of PVC plastic and having a nozzle 415 , and which are spaced equidistantly from each other and connected to the horizontal PVC piping encased within PVC pipe 810 . The vertical members 410 are mounted onto metal frame 840 , to which PVC pipe 810 is also attached. The frame 810 comprises two metal handles 830 , which can be held by users and utilized to maneuver device 800 around a field for planting.
[0088] Device 800 also features two skis 820 . The skis 820 are comprised of a metal, such as steel or aluminum, or a plastic, such as PVC. The device 800 slides on skis 820 as the users maneuver device 800 around a field, using handles 830 , to plant seeds in neat, equidistant rows from the nozzles 415 of the vertical tubes 410 of device 800 . | The present invention describes an air-powered device that propels seed from a storage container and distributes seeds from a horizontal tube into a series of vertical tubes, and shoots the seeds from those vertical tubes into the ground. The device can be carried by a human user or mounted on a cart having wheels or skis, and towed through a field while being used to plant seed. The different methods of carrying and operating the device enable farmers to utilize the device in different types of terrain and during different condition. The device can be manufactured from common, affordable materials, such as PVC, and offers rural farmers a portable solution for planting their crops that is efficient and low-cost. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application Ser. No. 61/109,337 filed on Oct. 29, 2008, entitled “ENDOSCOPE ENDCAP FOR SUTURING TISSUE” the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to medical systems, devices and procedures for suturing tissue, and more particularly to endoscopically suturing openings in tissue.
BACKGROUND OF THE INVENTION
Openings or perforations in the walls of internal organs and vessels may be naturally occurring, or formed intentionally or unintentionally. These openings may be used to gain access to adjacent structures of the body, such techniques being commonly referred to as transluminal procedures. For example, culdoscopy was developed over 70 years ago, and involves transvaginally accessing the peritoneal cavity by forming an opening in the cul de sac. This access to the peritoneal cavity allows medical professionals to visually inspect numerous anatomical structures, as well as perform various procedures such as biopsies or other operations, such as tubal ligation. Many transluminal procedures for gaining access to various body cavities using other bodily lumens have also been developed. Natural orifices such as the mouth, nose, ear, anus or vagina may provide access to such bodily lumens and cavities. The bodily lumen(s) of the gastrointestinal tract are often endoscopically explored and can be utilized to provide access to the peritoneal cavity and other body cavities, all in a minimally invasive manner.
Compared to traditional open surgery or laparoscopic surgery, transluminal procedures are less invasive by eliminating abdominal incisions (or other exterior incisions) and incision related complications, while also reducing postoperative recovery time, reducing pain, and improving cosmetic appearance. At the same time, there remain challenges to transluminal procedures, including providing a suitable conduit to the openings and body cavities, robust medical devices that are maneuverable via the conduit and operable within the body cavity, sterility of the conduit, maintaining insufflation of the body cavity, proper closure of the opening, and prevention of infection. For example, when an opening is formed in a bodily wall of the gastrointestinal tract, such as in the stomach or intestines, spillage of the stomach contents, intestinal contents or other bodily fluids into the adjacent body cavity can occur. Travel of bacteria laden fluids outside of the gastrointestinal tract may cause unwanted and sometimes deadly infection.
In order to permanently close naturally occurring, intentionally or unintentionally formed perforations and allow the tissue to properly heal, numerous medical devices and methods have been developed employing sutures, adhesives, clips, tissue anchors and the like. One such class of devices aims to endoscopically close perforations, such as those within the gastrointestinal tract. Accordingly, various medical devices have been proposed that attach to the endoscope to facilitate perforation closure. Some of these medical devices employ suction to orient the tissue for suturing or anchor placement, while others employ tissue graspers or other devices to orient the tissue.
BRIEF SUMMARY OF THE INVENTION
The present invention provides medical devices, systems and methods for suturing a perforation in tissue, that may be used endoscopically and/or laparoscopically, and that offer simple, reliable and controllable placement of sutures around a perforation for complete closure thereof. One embodiment of a medical device, constructed in accordance with the teachings of the present invention, generally includes an endcap for use with an endoscope to suture an opening in tissue using a tissue anchor. The endcap has a tubular shape defined by an annular sidewall, and the sidewall defines an interior space. A side port is further defined by the annular sidewall and is in communication with the interior space. The side port is sized to receive and locate the tissue within the interior space for suturing. A support rib is positioned within the interior space and distal to the side port. The support rib extends laterally from a first position on the sidewall to a second position on the sidewall. The support rib and sidewall define a piercing aperture therebetween which is sized to be larger than a length of the tissue anchor, allowing the anchor to freely exit the interior space via the piercing aperture and side port.
According to more detailed aspects of the medical devices, the piercing aperture and the side port are located on the same lateral side of the endcap and preferably engage each other over a line. The support rib is preferably oriented longitudinally, and bisects a portion of the interior space that is distal to the side port. The endcap may also include an end wall, wherein the support rib preferably extends between the end wall and the first and second positions along the sidewall. In preferred constructions, a majority of the end wall is exposed to the endoscope permitting visualization through the end wall, and thus the endcap is preferably formed of an optical-grade plastic. The edge of the support rib defines a support surface, and together with a portion of the sidewall that is exposed by the side port, define an annular support surface for supporting the tissue during suturing.
One embodiment of a medical system, constructed in accordance with the teachings of the present invention, generally includes an endoscope, a needle assembly and an endcap. The endoscope has a working channel defining a longitudinal axis. The needle assembly has a needle defining a distal end and a needle lumen. A tissue anchor is slidably received within the needle lumen, and a suture is attached to the tissue anchor. The needle assembly is slidably received within the working channel of the endoscope. The endcap has an annular sidewall defining a proximal interior space, and an intermediate interior space, and a distal interior space. The proximal interior space is sized to receive a distal end of the endoscope. The side wall defines a side port in communication with the intermediate interior space and is sized to receive the tissue therein. The endcap includes a support rib bisecting the annular sidewall and the distal interior space to define an anchor ejection portion of the distal interior space. The anchor ejection portion is sized to receive the tissue anchor therein when the tissue anchor is in a lengthwise orientation.
According to more detailed aspects of the medical systems, the anchor ejection portion of the distal interior space is circumferentially aligned with the working channel of the endoscope. The anchor ejection portion of the distal interior space is in direct communication with the side port without any intervening structure therebetween. The area between the ejection portion of the distal interior space and the intermediate interior space defines a piercing aperture that is preferably sized to pass the tissue anchor therethrough in its lengthwise orientation.
Methods for suturing an opening in tissue utilizing the medical devices and systems described above is also provided in accordance with the teachings of the present invention. The endcap of the medical device is fitted to the distal end of the endoscope. The endoscope and medical device are introduced to a first site proximate the opening, and the tissue is positioned within the intermediate interior space of the endcap. The needle assembly is advanced distally through the tissue and the piercing aperture. A tissue anchor is deployed into the distal interior space, and the needle assembly is retracted proximally through the tissue. The endoscope and medical device can then be moved along the periphery of the opening while the tissue remains within the intermediate interior space, whereby the tissue anchor passes directly back through the piercing aperture and exits the side port. The needle assembly is advanced distally through the tissue at a second site proximate the opening and a second tissue anchor is deployed. The free ends of the suture are tightened to close the opening.
According to more detailed aspects of the methods, the free ends of the suture are pulled proximally to draw the tissue anchors closer together and close the opening. Preferably, the plurality of tissue anchors are connected to a single suture, and each tissue anchor is slidably attached to the suture. The method may thus further comprise the steps of positioning the plurality of tissue anchors around the opening and tensioning the ends of the suture to reduce the distance between the tissue anchors and compress the tissue around the opening to close the opening in a purse-string fashion.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a perspective view of a medical system constructed in accordance to the teachings of the present invention;
FIG. 2 is an exploded view of the medical system depicted in FIG. 1 ;
FIG. 3 is a cross-sectional view of a medical device forming a portion of the medical system depicted in FIGS. 1 and 2 ;
FIG. 4 is a cross-sectional view of the medical device depicted in FIG. 3 ;
FIG. 5 is a side view of a tissue anchor forming a portion of the medical system depicted in FIGS. 1 and 2 ;
FIGS. 6-13 are views illustrating use of the medical system depicted in FIGS. 1 and 2 to close an opening in tissue in accordance with teachings of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the present application, the term “proximal” refers to a direction that is generally towards a physician during a medical procedure, while the term “distal” refers to a direction that is generally towards a target site within a patient's anatomy during a medical procedure.
Turning now to the figures, FIGS. 1-2 depict a medical system 20 for suturing closed a perforation 10 in tissue 12 (see, e.g., FIG. 6 ), constructed in accordance with the teachings of the present invention. The medical system 20 generally comprises an endoscope 22 , a needle assembly 24 and a medical device 26 adapted for use with the endoscope 22 . The endoscope 22 may be any scope known to those skilled in the art, and therefore may have various lengths, diameters and functionality. The endoscope 22 generally defines a longitudinal axis 14 , and a working channel 28 extends longitudinally through the endoscope 22 . The needle assembly 24 is received within the working channel 28 , and as best seen in FIG. 2 includes a needle 30 with a needle lumen 32 receiving one or more tissue anchors 34 having suture 36 connected thereto. A stylet 38 or other pushing element is typically fitted within the needle lumen 32 to eject the anchors 34 , as is known in the art. Likewise, a needle sheath 40 may also be provided to shield and control exposure of the piercing distal tip 42 of the needle 30 .
The medical device 24 generally includes an endcap 42 having a tubular or annular sidewall 44 defining an interior space 46 accessible via a side port 48 for suturing the tissue 12 with the needle assembly 24 . A proximal portion 46 p of the interior space 46 is sized to receive the distal end of the endoscope 22 . The endcap 42 may be structured to frictionally engage the endoscope 22 for selective retention of the endcap 42 on the endoscope 22 , although other means for connecting the endcap 42 to the endoscope 22 may be employed, as is known in the art. The endoscope 22 and medical device 24 are therefore adapted to be traversed through the body of a patient in this connected configuration shown in the figures.
Turning now to FIGS. 3 and 4 , the medical device 26 has been shown in cross-section. The annular sidewall 44 defines an interior space 46 , portions of which include the proximal interior space 46 p , an intermediate interior space 46 i and a distal interior space 46 d . Adjacent the intermediate interior space 44 i , the sidewall 42 defines the side port 46 through which the tissue 12 enters the interior space 46 . The medical device 26 preferably also includes an endwall 50 located at the distal end of the sidewall 44 . The endwall 50 encloses the distal interior space 46 d , and is preferably constructed of an optical-grade plastic that permits the endoscope 22 to visualize through the endcap 26 , discussed in greater detail herein.
The medical device 26 also includes a support rib 52 which bisects the annular sidewall 44 in the distal interior space 46 d . On one side of the support rib 52 , there is an anchor ejection portion 54 of the distal interior space 46 d , which is defined by the space between the support rib 52 and sidewall 44 . The anchor ejection portion 54 of the distal interior space 46 d is sized to receive the needle assembly 24 , and in particular the needle 30 and the tissue anchor 34 . As best seen in FIG. 4 , the support rib 52 extends from a first position 52 a on the sidewall to a second position 52 b on the sidewall. Thus, the support rib 52 and sidewall 44 also define a piercing aperture 56 therebetween, which is the area where the anchor ejection portion 54 meets the intermediate interior space 46 i . The edge 58 of the support rib 52 defines a support surface, and together with the portion of the sidewall that is exposed by the side port 48 , defines an annular support surface for supporting tissue during suturing, as will be described in further detail herein. The anchor ejection portion 54 meets the side port 48 over a line, namely the curved line of the piercing aperture 56 defined by the sidewall 44 .
The piercing aperture 54 is semi-circular in shape (although it may have other shapes depending upon the tubular or annular shape of the endcap 42 ) defined by a largest diameter D 1 and a smallest diameter D 2 . Preferably the largest diameter D 1 is greater than a length L A of the tissue anchor 34 (shown in FIG. 5 ) while the smallest diameter D 2 is less than the length L A of the tissue anchor 34 . This helps to orient the tissue anchor 34 within the anchor ejection portion 54 of the distal interior space 46 d . In another embodiment, both the largest diameter D 1 and the smallest diameter D 2 may be greater than a length L A of the tissue anchor 34 . In either case, the anchor ejection portion 54 of the distal interior space 46 d is sized to receive the tissue anchor 34 therein while the tissue anchor 34 is in a lengthwise orientation, meaning its axis 37 extends laterally and is generally perpendicular to the longitudinal axis 14 (i.e. within about 15 degrees of perpendicular). Likewise, the tissue anchor 34 can pass through piercing aperture 56 in its lengthwise orientation. It will be recognized by those skilled in the art that the anchor ejection portion 54 of the distal interior space 46 d is in direct and immediate communication with the side port 48 without any intervening structure therebetween, permitting easy passage of the tissue anchor 34 .
The sidewall 44 preferably has a circular cross-sectional shape as shown, and the first and second positions 52 a , 52 b on the sidewall 44 span an arc A SR of less than about 180 degrees, although in other embodiments A SR can be about 180 degrees. The side port 48 spans a second arc A SP which is greater than the first arc A SR bisected by the support rib 52 . Accordingly, and as best seen in FIG. 4 , the edge 58 of the support rib 52 and the exposed sidewall 44 define a support surface that has a general D-shape (see, e.g., the un-hatched area shown in FIG. 4 ).
As best seen in FIG. 3 , the support rib 52 also extends longitudinally and engages the endwall 50 . The longitudinal length of the support rib 52 positions its support surface (namely edge 58 ) proximate the longitudinal position of the side port 48 . In the depicted embodiment, the endwall 50 has a semi-spherical shape to provide an atraumatic tip to the medical system 20 , although the endwall 50 may take other shapes such as flat or conical. Notably, a majority of the endwall 50 is exposed to the endoscope 22 (see, e.g., FIG. 8 ) thereby permitting visualization through the endwall 50 . As such, the medical device 26 , and in particular endcap 42 , is preferably formed of an optical-grade plastic that permits visualization therethrough. Suitable plastics include but are not limited to acrylic, polyacrylates, polyacrylonitrile, polyvinylchloride, polyetherketone, and polyethylene.
As shown in FIG. 5 , the tissue anchor 34 is preferably of a form where the anchor member is slidable relative to the suture 36 . One preferred tissue anchor 34 shown in FIG. 5 , and includes a wire loop 35 which slidably receives the suture 36 . Further details of this and other tissue anchors are disclosed in U.S. patent application Ser. No. 11/946,565 filed Nov. 25, 2007 and U.S. Pat. No. 5,123,914 issued Jun. 23, 1992, the entire contents of which are incorporated by reference herein.
One preferred method for utilizing the medical system 20 and its medical device 26 will now be described with reference to FIGS. 6-13 . As shown in FIG. 6 , an upper portion of the gastrointestinal tract 15 , such as the esophagus 16 and stomach 17 , may be accessed via the mouth (not shown). A cutting instrument, with or without the aid of an endoscope or other visualization device, may be employed to form an opening 10 in the gastric wall or gastric tissue 12 . Wire guides, dilators and other medical devices may be employed through the opening 10 to perform a translumenal procedure. These initial steps of the method have been described for reference purposes and to give context, and, it will be recognized that the medical system 20 of the present invention may be used to endoscopically suture any tissue within the body. Likewise, the medical system 20 may be employed through any natural orifice as (e.g., the mouth, anus, vagina, ears, nose.) as well as intentionally formed orifices such as those made during laparoscopic or similar procedures. The bodily opening 10 defined by the tissue of an internal bodily lumen may be intentionally formed or may be naturally occurring, and the internal bodily lumen may comprise a portion of the gastrointestinal tract or any other internal bodily lumen, as will be recognized by those skilled in the art.
The medical device 26 and its endcap 42 are fitted on the distal end of the endoscope 22 as shown in FIGS. 1 and 6 . The medical system 20 is introduced to a position proximate the opening 10 , and the distal portion of the endcap 42 is passed through the opening 10 as shown in FIG. 7 . As shown in FIG. 8 , the medical system 20 is manipulated such that the tissue 12 passes through the side port 48 and is positioned within the interior space 46 , and in particular the intermediate interior space 46 i . The visualization element 23 of the endoscope 22 is capable of visualizing the placement of the tissue 12 within the interior space 46 , and when there is no tissue 12 within the interior space 46 , it can visualize distally beyond the medical device 26 through the endwall 50 of the endcap 42 .
With the medical system 20 positioned at a first site along the tissue 12 proximate the opening 10 as shown in FIG. 8 , the needle assembly 24 and its needle 30 will be advanced distally through the working channel 28 of the endoscope 22 , through the tissue 12 , through the piercing aperture 56 and into the anchor ejection portion 54 of the distal interior space 46 d . Notably, the proximal edge 58 of the support rib 52 , as well as the exposed portion of the sidewall 44 , support the tissue 12 as the needle 30 is advanced therethrough. At the proximal end of the medical system 20 , the stylet 38 of needle assembly 24 may be moved relative to the needle 30 to deploy the tissue anchor 34 into the anchor ejection portion 54 of the distal interior space 46 d.
The needle assembly 24 may then be retracted proximally through the working channel 28 of the endoscope 22 such that it is removed from the tissue 12 while leaving the tissue anchor 34 on the distal side of the tissue 12 , as shown in FIG. 10 . The suture 36 will pass through the tissue 12 , and one end of the suture will continue through the working channel 28 and/or the needle 30 for connection to additional tissue anchors 34 and to the proximal end of the medical system 20 . The other free end of the suture 36 will pass through the side port 48 and along the exterior of the medical system 20 to a location outside of the body, whereby both ends of the suture 36 may be manipulated by the medical professional.
Due to the construction of the medical device 26 and its endcap 46 , the tissue anchor 34 is capable of moving through the anchor ejection portion 54 of the distal interior space 46 in its lengthwise orientation shown in FIG. 10 . Likewise, the piercing aperture 56 and the side port 48 permit the tissue anchor 34 to pass directly therethrough such that the medical system 20 may be slid along the periphery of the opening 10 in the tissue 12 to a second site proximate the opening 10 . When the medical system is moved, the tissue anchor 34 will simply exit the medical device 26 via the side port 48 and remain at the first site where it was deployed. The medical system 20 need not be slid along the periphery of the opening 10 , but may also be moved laterally away from the tissue 12 so that it exits the interior space 46 , whereafter a second site may be identified and targeted for deployment of additional tissue anchors 34 .
As shown in FIG. 11 , multiple tissue anchors 34 may be deployed around the periphery of the opening 10 in the tissue 12 , while the suture 36 largely remains on the proximal side of the tissue 12 . The plurality of tissue anchors 34 may be deployed around the opening 10 , such as in a generally circular configuration, although any number and any configuration of anchor deployment may be used, such as zig-zag configurations. Both of the free ends 36 a , 36 b of the suture 36 extend proximally through the bodily lumen and external orifice for individual manipulation by the medical professional to close the opening 10 . In particular, the ends 36 a , 36 b may be tensioned to reduce the distance between the tissue anchors 34 and compress the tissue 12 around the opening 10 to close the opening 10 in a purse-string fashion, as shown in FIG. 13 . A suture lock 60 may be employed to connect the ends 36 a , 36 b of the suture 36 together and maintain the tension thereon, although the suture 36 may also be tied using knots or other techniques or devices as will be readily appreciated by those skilled in the art. Several exemplary suture locks are disclosed in U.S. patent application Ser. Nos. 12/125,525 filed May 22, 2008 and 12/191,001 filed Aug. 13, 2008, the disclosures of which are incorporated herein by reference in their entirety.
It will be recognized by those skilled in the art that, while the methods described above generally include placing the tissue devices in tissue through an internal bodily lumen, it will be recognized that the systems, devices and methods may be used on any layer of material (e.g. fabrics, cloth, polymers, elastomers, plastics and rubber) that may or may not be associated with a human or animal body and a bodily lumen. For example, the systems, devices and methods can find use in laboratory and industrial settings for placing devices through one or more layers of material that may or may not find application to the human or animal body, and likewise closing holes or perforations in layers of material that are not bodily tissue.
The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Numerous modifications or variations are possible in light of the above teachings. The embodiments discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled. | Medical systems, devices and methods are disclosed for suturing a perforation in tissue, that may be employed endoscopically and/or laparoscopically, and that offer simple, reliable and controllable placement of suture around a perforation for complete closure thereof. One embodiment of the medical device generally includes an endcap for use with an endoscope to suture an opening in tissue using a tissue anchor. The endcap has a tubular shape defined by an annular sidewall, and the sidewall defines an interior space. A side port is further defined by the annular sidewall and is in communication with the interior space. The side port is sized to receive and locate the tissue within the interior space for suturing. A support rib is positioned within the interior space and distal to the side port. The support rib and sidewall define a piercing aperture therebetween that supports the tissue being sutured. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to halide scavengers having a trimodal pore size distribution and their use for treating gas and liquid streams. More particularly, the present invention relates to a process of using these halide scavengers for removing HCl from high temperature gas and liquid streams, especially in the production of synthesis gas.
BACKGROUND OF THE INVENTION
[0002] The term “porosity” refers to pore space in a material. It can be defined as the fraction of the bulk volume that is occupied by pores or by void space. The individual pores may vary greatly in size and shape within a given solid, and between a given solid and another solid. The width of the pores is commonly assumed to be the diameter of a cylindrical pore, or the distance between the sides of a slit or narrow-shaped pore.
[0003] The International Union of Pure and Applied Chemistry issued in 1991 (P URE & A PPL . C HEM ., Vol 63, N 9, pp 1227-1246, 1991) provides the following recommendations to classify pores according to their size:
Macropores—widths exceeding about 50 nm (nanometers) Mesopores—widths between 2 and 50 nm Micropores—smaller than 2 nm
[0007] Mercury intrusion appears to be the most popular method to assess the pore distribution in the meso- and macro-region of pore widths whereas physical adsorption is the main method to measure the micro pores. The common principles of porous solid creation include phenomena such as aggregation and agglomeration; re-crystallization; subtraction and addition. For example, porous glasses are prepared by leaching non-porous templates. The porous structure of zeolites, aluminas and silicas can vary with conditions of crystallization and spray drying. Sintering can be also used to change the pore volume of alumina but the BET surface area decreases in such an operation.
[0008] The preparation of carbon molecular sieves is an example of pore structure altering by addition. Treating source particles with hydrocarbons at suitable conditions leads to carbon film deposits at the pore mouths causing narrowing the pores.
[0009] There are numerous patents related to the pore system of alumina based supports and catalysts. Some of them are listed as follows: U.S. Pat. No. 4,001,144; U.S. Pat. No. 4,140,773; U.S. Pat. No. 4,179,411; U.S. Pat. No. 4,301,037; U.S. Pat. No. 4,548,709; U.S. Pat. No. 5,260,241; U.S. Pat. No. 6,403,256; U.S. Pat. No. 6,589,908; and U.S. Pat. No. 6,984,310.
[0010] In these patents, the pore structure of alumina is created or altered by means such as selection of crystallization conditions, presence of seeds, specific extrusion conditions, additives and etc. The paper “Preparation of Bimodal Aluminas and Molybdena/Alumina Extrudates” by R. E. Tischer published in J OURNAL OF C ATALYSIS , Vol. 72, pp 255-265, 1981 describes the following methods to produce bimodal pore structure in alumina extrudates: Partial peptization, coextrusion of salt/Boehmite mixtures, and incorporation of combustible fiber such as filter pulp.
[0011] The closest prior art to the present invention is described in U.S. Pat. No. 6,403,526 where the alumina is derived from a mixture of Gibbsite (ATH) and active alumina and an additive component is used as well. Another close art is reported in U.S. Pat. No. 4,001,144 where an alumina precursor of chi-rho-eta structure is treated with carbonate or bicarbonate solutions under pressure at about 100° to 160° C. However, the invention described herein is very different from this prior art.
[0012] Acid gases are present as impurities in numerous industrial fluids, i.e., liquid and gas streams. These acid gases include hydrogen halides such as HCl, HF, HBr, HI and mixtures thereof. Hydrogen chloride is a problem in particular. Usually, HCl is removed at ambient temperature with alkali metals modified alumina or metal oxide (mostly ZnO) sorbents. On the other hand, high temperature chloride scavengers are needed for some industrial applications such as the production of hydrogen by steam reforming of hydrocarbons. In these applications, the hydrocarbon feed first passes through a hydrodesulfurization (HDS) or hydrogenation stage that converts the organo-chloride contaminants to HCl. Since the HDS process operates at 350° to 400° C., it is advantageous if the next stage of chloride scavenging also occurs at a high temperature.
[0013] Use of alumina loaded with alkali metals as an HCl scavenger is the current “state of the art” solution for the purification of hydrocarbon streams at high temperatures. However, the standard zinc oxide based sorbents cannot be applied in such applications because of the volatility of the resulting zinc chloride product.
[0014] The existing sorbents for high temperature applications need improvements in terms of chloride loading, reduced reactivity towards the main stream and physical stability in service.
[0015] Alumina modified with alkali or alkaline earth elements is known as a good chloride scavenger. Recently, Blachman disclosed in U.S. Pat. No. 6,200,544 an adsorbent for removing HCl from fluid streams comprising activated alumina impregnated with alkali oxide and promoted with phosphates, organic amines or mixtures thereof.
[0016] In an attempt to increase the adsorbent performance, U.S. Pat. No. 5,897,845 assigned to ICI claimed absorbent granules comprising an intimate mixture of particles of alumina trihydrate, sodium carbonate or sodium bicarbonate or mixtures thereof and a binder wherein the sodium oxide (Na 2 O) content is at least 20% by weight calculated on an ignited (900° C.) base. This material was designated for use at temperatures below 150° C.
[0017] The present application targets developing alumina particulates with special pore structure suitable for mass-transfer limited applications. A practical and cost effective method to produce such alumina particulates is targeted as well. There are many examples of the positive effect of the presence of large pores in catalysts and adsorbents. Hydrotreatment of petroleum fractions is an appropriate example on the catalyst side while HCl removal from gas and liquid streams illustrates the technical problem to be solved on the adsorbent side. The present application focuses on the latter.
[0018] Trace hydrogen chloride contaminates the effluent in major catalytic processes in the hydrocarbon industry such as the UOP processes CCR Reforming and Oleflex. If not removed from the effluent, HCl can cause corrosion and plugging of the equipment and poison sensitive catalysts downstream. Therefore, HCl scavengers are regularly used in the hydrocarbon industry. Alumina modified with alkali, mostly sodium, and alkaline earth, mostly calcium, metals dominates the HCl removal applications. Some other metal oxide or carbonate based materials are also in use.
[0019] The plugging of the pore structure with “green oil” produced via side reactions of reactive stream components on the chlorinated scavenger (adsorbent) is a common cause of premature failure of the scavenger. Another cause is the liquid condensation in the pore system especially when two phase flow occurs. In both cases, the efficiency of the material decreases dramatically. Often, replacement with the fresh material only solves the problem.
[0020] The special trimodal pore structure provided with this invention best addresses the problems of current industrial HCl scavengers. Moreover, the special pore structure of the alumina is combined with a high concentration of the active component, an alkali metal, which determines the performance potential in HCl removal.
[0021] Last, but not least, all this is achieved in a cost effective manner. Generally, HCl in gas or liquid hydrocarbon streams must be removed from such streams to prevent unwanted catalytic reactions and corrosion to process equipment. Furthermore, HCl is considered a hazardous material and the release of HCl to the environment needs to be avoided.
[0022] There are currently two main classes of HCl scavengers. The first group comprises the alkali or alkaline-earth doped aluminas. The alkali metal content of these adsorbents calculated as an oxide (Na 2 O) is typically between 8 and 10%. The scavengers of this group achieve a relatively low Cl loading, typically 7 to 9%. The second group consists of intimate mixtures of alumina, carbonate (bicarbonate) and binder. A typical material from this group is described in U.S. Pat. No. 5,897,845. The Na 2 O content is at least 20 mass-%, which determines the high potential Cl loading of this material. However, scavengers of this type cannot be used at temperatures higher than 150° C. They have low BET surface area and insufficient porosity to provide high loading and the inability to function at the high temperatures present in certain applications. For example, in the '845 patent, minimum BET surface area is greater than 10 m 2 /g and one commercial product that is intended for high temperature chloride removal has a BET surface area of about 66 m 2 /g. Accordingly, there remains a need for improved halide scavengers with high loading capacity that can operate at high temperatures, such as above 150° C.
SUMMARY OF THE INVENTION
[0023] The invention creates a unique trimodal pore system of alumina adsorbents and catalysts in a cost effective manner. Wide meso pores dominate the pore structure. In the case of Cl adsorbents, the pore forming step is combined with the actual process of introducing the active component and the final agglomeration step to produce properly sized particulates. The final product has high performance in HCl removal combined with low reactivity towards sensitive components in the stream to be purifies. It has also improved resistance towards liquid condensation in the pores—the HCl removal capability remains practically unchanged under harsh condensation conditions.
[0024] The composite sorbents prepared according the present invention have significant advantages over the prior art since they are lower cost materials exhibiting high BET surface area and porosity along with a high content of active component. These properties translate to high dynamic capacity in HCl removal from both gas and liquid fluids. A further advantage compared to some other prior art sorbents is that the sorbents of this invention do not require a separate binder to be added to the mixture in the forming process. They have sufficient mechanical stability in both their fresh and spent state along with low reactivity towards the main stream. The invention comprises a process for making an adsorbent and the uses that can be made of this adsorbent. One method of preparation of the adsorbent comprises mixing at least one alumina compound with a solid metal carbonate and adding or spraying water on the mixture. In the practice of the present invention, the term “carbonate” includes inorganic compounds containing a CO 3 moiety including a bicarbonate or a basic carbonate. Then the mixture is allowed to stay at ambient conditions to cure or is maintained at an elevated temperature between about 25° and 150° C. for a period long enough for the materials to react. The appropriate combination of reaction time and temperature can be readily determined by one skilled in the art. A longer time is needed at lower temperatures within the stated range. In addition, in the practice of the present invention, a second step of thermal treatment follows the curing step. In this thermal treatment that is a reactive cure, a temperature between 250° and 500° C. is needed in order to compose the material formed in the first step resulting in a reactive species that is useful in scavenging HCl in high temperature applications. Preferably, the temperature is between 320° and 480° C. The sorbent has a BET surface area of from about 50 to 200 m 2 /g and typically comprises about 10 to 25 mass-% Na 2 O. A particularly useful carbonate is a sesquicarbonate. The metal in the metal carbonate may be sodium, potassium, lithium, zinc, nickel, iron or manganese. Other metals may be used as known to those skilled in the art.
[0025] The invention also comprises a process for the removal of at least one hydrogen halide from a fluid or gaseous stream comprising hydrogen, hydrocarbons, water, or other gases such as nitrogen and hydrogen halide, wherein said process comprises contacting said fluid stream with a sorbent material in a packed bed, said sorbent material comprising a reaction product of at least one alumina and at least one solid metal carbonate. The solid metal carbonate is preferably at least one sesquicarbonate. The hydrogen halide is selected from the group consisting of hydrogen chloride, hydrogen fluoride, hydrogen iodide, hydrogen bromide and mixtures thereof. The invention is useful in the treatment of a fluid stream comprising a net hydrogen stream from a catalytic reforming process, where the hydrogen halide is hydrogen chloride. The invention is also useful in the treatment of a net hydrogen stream from a light paraffin dehydrogenation process where the hydrogen halide is also hydrogen chloride.
DETAILED DESCRIPTION OF THE INVENTION
[0026] At least two solid and one liquid component are needed to produce the reactive composite sorbent of the present invention. At least one carbonate powder and at least one alumina powder comprise the solid components and water or an aqueous solution of at least one salt is the liquid component.
[0027] The carbonate powder is preferably an alkali metal carbonate in a powder form. Small particles, preferably about 5 to 10 microns in diameter, are employed. A carbonate component that has been found to provide excellent results in the present invention is the natural carbonate (soda ash) ore known as Trona or Nahcolite. A popular source of such natural carbonate is the Green River occurrence in Wyoming, US. The book NATURAL SODA ASH: OCCURRENCES, PROCESSING AND USE, authored by Donald E. Garrett, Van Nostrand Reinhold publication, 1992, summarizes important characteristics of natural carbonates. Other carbonates that can be used include Wegscheiderite (Na 2 CO 3 .NaHCO 3 ), Thermonatrite (Na 2 CO 3 H 2 O), Shortite (Na 2 CO 3 .2CaCO 3 ), and Eitelite (Na 2 CO 3 .MgCO 3 ).
[0028] One such carbonate that has been found especially useful is a natural sodium sesquicarbonate, marketed by Solvay Chemicals, Houston, Tex. as Solvay T-200®. A sesquicarbonate has a formula of Na 2 CO 3 .NaH CO 3 .2H 2 O. It produces 1.5 mols sodium carbonate (Na 2 CO 3 ) upon heating at sufficiently high temperature. Table 1 presents some properties of this product as reflected in the producer's technical data sheet.
[0000]
TABLE 1
Component
Typical Analysis
Na 2 CO 3 •NaHCO 3 •2H 2 O
97.5%
Free Moisture
0.01
Water Insoluble
2.3%
NaCl
0.1
Bulk Density
785 kg/m 3 (49.0 lbs/ft 3 )
Particle Size
Sieve Opening, micrometers
Weight Percent
<70
75
<28
50
6
10
[0029] The carbonate raw material was found to have a typical FTIR (Fourier Transform Infrared) spectrum characterized with absorbance peaks at about 3464, 3057, 1697, 1463, 1190, 1014, 850 and 602 cm −1 , corresponding to the values published for this material. The final product of the present invention had an FTIR spectra exhibiting at least two peaks selected from absorbance peaks at 880, 1103, 1454, 1410, 1395, 1570, and 1587 cm −1 .
[0030] An alumina powder that has been found to be useful in the present invention is a transition alumina powder produced by the rapid calcination of Al(OH) 3 , known as Gibbsite. Alumina A-300, sold by UOP LLC, Des Plaines, Ill., is a typical commercial product that is suitable as a component of the reactive composite of the present invention. This alumina powder has a BET surface area of about 300 m 2 /g and about 0.3 mass-% Na 2 O. It contains only a few percent free moisture and is capable of fast rehydration in the presence of water. The FTIR spectrum of A-300 has the broad absorbance peaks due to Al—O vibration at about 746 and 580 cm −1 , with only a few additional peaks of OH (3502 and 1637 cm −1 ) and CO 3 of surface carbonate species (1396 and 1521 cm −1 ) are present.
[0031] The third component is water, or optionally an aqueous solution of a salt, which plays an important role in facilitating a reaction between the carbonate and alumina powder. The preferred salts include metal salt is selected from the group consisting of sodium acetate, sodium oxalate and sodium formate. The preferred average particle size D50 for the alumina component and the carbonate ingredient is from about 5 to 12 μm, although larger particles may be used, especially for the carbonate ingredient. The alumina and the sesquicarbonate are present in a ratio of about 0.8 to about 5. Preferably, the alumina and the sesquicarbonate are present in a ratio of about 2 to 4.
[0032] It has been found that that there is no reaction between the sesquicarbonate and alumina when a mixture is heated in a dry state to about 100° C. However, heating the dry mix to an initial temperature of from about 300° to about 600° C. converts the sesquicarbonate to sodium carbonate. In contrast, the presence of additional water followed by brief calcination at 100° C. triggers a reaction between the sesquicarbonate and alumina. The product was found to have the structure of Dawsonite crystals with a particle size of less than about 0.02 micrometers. In the present invention, thermal treatment at temperatures from at least 250° up to about 500° C. has been found to produce an adsorbent that is very effective in removal of acid halides at high temperatures. Preferably, this thermal treatment or reactive cure is at a temperature that is equal to or exceeds the temperature that the sorbent is decided to operate at in removal of acid halides. Example 1 describes the process to produce this phenomenon.
EXAMPLE 1
[0033] An industrial disk nodulizer was operated continuously at standard conditions for forming beads by delivering about 0.65 parts powder mix consisting of A-300 alumina and Solvay T-200® carbonate and about 0.35 parts water. The powder and water parts are expressed as the mass flows into the nodulizer. The whole system was operated in the regime of forming alumina beads of 5×8 mesh as the primary size.
[0034] The content level of Solvay T-200® carbonate was adjusted to obtain about 10.5 mass-% Na 2 O concentration in the final material. The discharging flow from the nodulizer was directed via a heated belt to a curing bin and subsequently to a moving bed activator where the beads were heated at about 400° C. The final material then was designated as Sample A.
EXAMPLE 2
[0035] The conditions of Example 1 were used wherein the carbonate (Solvay T-200®) content of the powder feed was maintained at a level to produce about 12.5 mass-% Na 2 O in the final product. The material was designated as Sample B.
EXAMPLE 3
[0036] The conditions of Example 1 were used whereas the carbonate (Solvay T-200®) content of the powder feed was maintained at a level to produce about 12 mass-% Na 2 O in the final product. The material was designated as Sample C.
EXAMPLE 4
[0037] In this comparison example, a traditional sodium containing alumina for HCl removal applications was produced according to the established procedure in the industrial scale nodulizer. Most of the sodium in the final material was supplied in liquid form as sodium acetate. The manufacturing included also curing and activation steps at similar conditions as Examples 1-3. The final material was designated as Sample D. It contained about 7.5 mass-% Na 2 O.
EXAMPLE 5
[0038] This was a commercial silica alumina for comparison. It is designated as Sample E.
EXAMPLE 6
[0039] This was a commercial alumina adsorbent used mainly as a desiccant. It is designated as Sample F.
[0040] An examination of the materials produced according the present invention (Samples A-C) found that the samples had most of their pore volume included in a wide mesopore range from about 15 to about 50 nanometers.
[0041] The differential pore distribution of all materials prepared according the invention (Samples A-C) exhibited a specific pore range of wide mesopores. As a matter of fact, these materials posses a trimodal pore distribution while the other samples have a typical bimodal pore distribution consisting of large macro pores formed by packing of the primary particles and small pores due mostly to the internal porosity of the particles. The Hg intrusion technique was used to measure the pore distribution of the sample. This technique can be also used to estimate the surface area included in the different pore ranges assuming that all pores have a cylindrical shape. A remarkable feature of the samples of the present invention is that they create much larger surface area in the important pore range between about 15 and 50 nm than all other samples.
[0000]
TABLE 2
Hg pore
volume
% in pores
% above
Sample
Type
Class
cc/g
15-50 nm.
50 nm
A
Alumina
Invention
0.347
40
30
composite
B
Alumina
Invention
0.333
36
39
composite
C
Alumina
Invention
0.346
49
30
composite
D
Modified
Commercial
0.365
7
42
alumina
E
Silica-alumina
Commercial
0.162
8
57
F
Alumina
Commercial
0.29
13
21
desiccant
[0042] Table 2 shows that the samples according to invention exhibit very high percentage of pores between 15 and 50 nanometers while still have sufficient macropores above 50 nm.
[0043] Table 3 summarizes the data with respect of the surface area of the samples. It is known that phenomena such as adsorption and catalysis are very much surface dependant. However, it is not sufficient just to have high surface area but also this surface area to be located in accessible sites. Narrow pores may sometimes cause mass transfer problems especially with two phase flow and conditions for liquid condensation.
[0000]
TABLE 3
% Hg
Hg
Ratio Hg
surface
BET
intrusion
surface
area in
surface
surface
area/BET
pores
area
area
surface
larger than
Sample
Type
Class
m 2 /g
m 2 /g
area
15 nm
A
Alumina composite
Invention
176
89
0.51
25
B
Alumina composite
Invention
169
74
0.44
27
C
Alumina composite
Invention
183
77
0.42
34
D
Modified alumina
Commercial
195
127
0.65
6
E
Silica-alumina
Commercial
670
44
0.07
7
F
Alumina desiccant
Commercial
350
145
0.41
1
[0044] Since mercury does not penetrate pores smaller than about 3.7 nanometers and the BET does not count the large pores, the ratio of the Hg and N 2 derived surface area should give a rough approximation about the proportion of large pores (both meso- and macro) in a porous solid. All the solids in Table 3, except Sorbead that is known as microporous, have similar different ratios of Hg versus BET derived surface area. These ratios range between 0.41 and 0.65 and between 0.42 and 0.51 for the samples according to the invention.
[0045] However, the last column in Table 3 reveals the most important difference between the samples. The materials of the invention have a large portion (25-34%) of the Hg accessed surface area incorporated in pores larger than 15 nanometers. This percent is between 1 and 7 in the comparison samples in Table 3. The data above illustrate the unique properties of the invented materials.
[0046] The pore structure revealed in this invention may be useful for certain applications such as HCl removal from gas stream at conditions of liquid condensation. A flow reactor loaded with about 55 cc representative sample of the traditional material—Sample D or the invented material—Samples A-C were purged with N 2 gas containing about 1 vol-% HCl. In a second run with each material, the sample was first soaked in gasoline and the same procedure as in “dry” conditions was repeated. The presence of liquid did not affect the HCl breakthrough time of Samples A-C while the performance of the reference Sample D was substantially diminished at the same test conditions. A calibrated alkali solution was used in all cases to detect the HCl breakthrough.
[0047] A cost effective way to practice the invention was described above. Other approaches are feasible as long as there are proper conditions for the alumina—carbonate reaction to occur. Beside sodium, ammonium, potassium and lithium are known to form Dawsonite—type hydroxyl carbonates upon reaction with alumina. The ammonium is especially useful in the case of catalyst base where excess alkali metal is not desired.
[0048] Although not illustrated here, there is a possibility that other elements such as alkaline earth elements and even transitional metals may react with rehydratable alumina at proper conditions. Such reactions are expected to produce hydrotalcite type intermediates and, hence, cause favorable changes in the pore distribution upon agglomeration and subsequent activation. | Wide mesoporous alumina composites are produced by an “in situ reaction” route comprising agglomeration of an alumina powder that is capable of rehydration together with a second reactive powder such as carbonate. In one method of production, the powders are fed to a rotating forming device that is continuously sprayed with liquid under conditions to form particulates. The discharging beads are then subjected to curing and thermal activation to produce the final catalyst or adsorbent. The alumina participates in a pore altering process involving the carbonate component upon formation of hydroxycarbonate intermediates such as Dawsonite. Large fraction of the pore volume of the final product consists of wide mesopores in the 15-50 nanometers range. The alumina composites exhibit a characteristic trimodal pore structure that includes also small micro-meso pores and macropores larger than 200 nanometers. | 1 |
TECHNICAL FIELD
[0001] The present invention relates to a method of determining whether a dialogue is displayable in an input operation of an operator of a terminal. Particularly, the present invention relates to a method of preventing the likelihood that a display of a dialogue disturbs an operator's business.
BACKGROUND ART
[0002] PTL 1 discloses a technique in which a burden on an operator of a terminal is considered concerning asset management related to information processing or a software distribution function. PTL 1 discloses a software update system of reducing a burden on a user (an operator of a terminal), and a software update frequency is adjusted based on a frequency of use from a use state of software for each user.
CITATION LIST
Patent Literature
[0003] PTL 1: JP 2009-217517 A
SUMMARY OF INVENTION
Technical Problem
[0004] There are various cases in which an operation such as information processing-related asset management or software distribution gives a burden on the user (the operator of the terminal). For example, in a software distribution function (when software of an interactive installation format is distributed) or a user information input function of an information-related asset, when an administrator executes the function at a unilateral timing without considering the user's business circumstances, it requests the user to perform an operation, or a dialogue is displayed during business, and thus the user's business is disturbed, and a burden is given.
[0005] However, in the technique of the related art disclosed in PTL 1, the user's burden can be reduced by reducing the software update frequency, but it is difficult to prevent the likelihood that the user's business is disturbed at a software update timing. Further, it is hard to apply the technique disclosed in PTL 1 to an input of new software distribution or information processing-related asset management.
[0006] It is an object of the present invention to control a display timing of a dialogue necessary for an operator's task based on a state in an input operation of an operator of a terminal.
Solution to Problem
[0007] A method of determining whether a dialogue is displayable, including: recording a previous software use state in a terminal which has been responded to an input operation to the terminal; comparing the recorded previous software use state with a current software use state in the terminal; and displaying an input operation dialogue according to a result of the comparison is disclosed.
Advantageous Effects of Invention
[0008] According to the present invention, it is possible to control a display timing of a dialogue necessary for an operator's task.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a configuration diagram of a computer system according to the present embodiment.
[0010] FIG. 2 is a diagram illustrating a configuration of a user information table.
[0011] FIG. 3 is a diagram illustrating a configuration of a group information table.
[0012] FIG. 4 is a diagram illustrating a configuration of a software information table.
[0013] FIG. 5 is a diagram illustrating a configuration of an operation history information table.
[0014] FIG. 6 is a diagram illustrating a configuration of an analysis information table (dynamic generation).
[0015] FIG. 7 is a diagram illustrating a configuration of an analysis result table (dynamic generation).
[0016] FIG. 8 is a diagram illustrating a process outline according to the present embodiment.
[0017] FIG. 9 is a flowchart illustrating a process of a management program.
[0018] FIG. 10 is a flowchart illustrating a process of a management client program.
[0019] FIG. 11 is a flowchart illustrating the process of the management client program (subsequent to FIG. 10 ).
[0020] FIG. 12 is a flowchart illustrating a process of determining whether a dialogue display has to be executed.
[0021] FIG. 13 is a flowchart illustrating a process of storing an operation result of an operator through a management program.
[0022] FIG. 14 is a flowchart illustrating a process of creating timing determination information.
[0023] FIG. 15 illustrates an exemplary screen used to select an apparatus of an operator.
[0024] FIG. 16 illustrates an exemplary screen used to select an operation menu.
[0025] FIG. 17 illustrates an exemplary screen used to select an execution timing.
[0026] FIG. 18 illustrates an exemplary screen of an operator terminal.
DESCRIPTION OF EMBODIMENTS
System Configuration
[0027] FIG. 1 is a configuration diagram of a computer system (hereinafter, “system”) according to the present embodiment. The system is configured such that a management server 100 is connected with a plurality of operator terminals 160 a to 160 d via a network 150 .
[0028] The management server 100 includes an input/output (I/O) device 120 through which an administrator performs an I/O operation, a memory/HDD 110 serving as a storage apparatus, a central processing unit (CPU) 130 , and an NIC 140 serving as an interface (I/F) to the network 150 . The memory/HDD 110 stores a management program 111 serving as a main entity of an operation in the management server 100 , a program including a distribution target program installer 112 of distributing a program to each operator terminal, and various kinds of information such as user information 113 , software information 114 , analysis information (dynamic generation) 115 , group information 116 , operation history information 117 , and analysis result (dynamic generation) 118 . The analysis information 115 , and the analysis result 118 are dynamically generated as the management program 111 is executed as will be described later.
[0029] The operator terminal 160 includes an I/O device 180 through which an operator performs an I/O operation, a memory/HDD 170 serving as a storage apparatus, a CPU 192 , and an NIC 191 serving as an I/F to the network 150 . The memory/HDD 170 stores a management client program 171 serving a main entity of an operation in the operator terminal 160 , programs such as an application A 172 , an application B 173 , and a distributed program 174 , and timing determination information 175 .
[0030] In the following description, expressions such as “aaa table,” “aaa list,” “aaa database (DB),” and “aaa queue” are used, but the information need not be necessarily expressed by a data structure such as a table, a list, a DB, or a queue. For this reason, in order to indicate independence from a data structure, there are cases in which “aaa table,” “aaa list, “aaa DB,” “aaa queue,” or the like is referred to as “aaa information.”
[0031] Further, when content of each information is described, expressions such as “identification information,” “identifier,” “title,” “name,” or “ID” are used, but these expressions can be replaced with each other.
[0032] In the following description, there are cases in which a description proceeds using a “program” as a subject, but since a program performs a process decided as it is executed by a processor while using a memory, a communication port (a communication control apparatus), or the like, a description may proceed using a processor as a subject. Further, a process in which a program is disclosed as a subject may be a process performed by a computer such as a management server or an information processing apparatus. Furthermore, a part or all of a program may be implemented by dedicated hardware.
[0033] Further, various kinds of programs may be installed in a program distribution server or in each computer through a computer-readable memory medium. In this case, the program distribution server includes a CPU and storage resources, and storage resources store a distribution program and a program of a distribution target. As the distribution program is executed by the CPU, the CPU of the program distribution server distributes a distribution target program to another computer.
[0034] Further, a management computer includes an I/O device. As an example of the I/O device, a display, a keyboard, or a pointer apparatus is considered, but any other apparatus may be used. Further, instead of the I/O device, a serial interface or an Ethernet (a registered trademark) interface may be used as an I/O device, the corresponding interface may be connected with a display computer including a display, a keyboard, or a pointer apparatus, and an input and a display in the I/O device may be replaced by transmitting display information to a display computer or receiving input display information from the display computer and performing a display through the display computer.
[0035] Further, there are cases in which a set of one or more computers managing an information processing system and displaying display information are referred to as a “management system.” When the management computer displays display information, the management computers serve as the management system, and a combination of the management computer and the display computer serves as the management system as well. Further, in order to increase a speed or reliability of a management process, the same process as in the management computer may be implemented by a plurality of computers. In this case, the corresponding computers (including the display computer as well when the display computer performs a display) serve as the management system.
[0036] (Various Kinds of Information)
[0037] FIG. 2 illustrates a user information table 113 storing information (profile information of a user who is an operator) related to each user, and the user information table 113 stores a user ID 113 a , a user title 113 b , a department 113 c to which the user belongs, a title 113 d , and an occupational category 113 e for each user. The information is created by an input by the administrator, information acquisition from the operator by a user information input function of an information processing-related asset, and information acquisition by active directory collaboration. The user refers to the operator who operates the terminal 160 .
[0038] FIG. 3 illustrates a group information table 116 , and three tables (a), (b), and (c) configuring the group information table 116 are information in which a department ID 116 a - 1 to which each user belongs, a title ID 116 b - 1 , and an occupational category ID 116 c - 1 are associated with a department 116 a - 2 , a title 116 b -2, and an occupational category 116 c - 2 , respectively. The group information table 116 is created as necessary when data related to a new user is added to the user information table 113 illustrated in FIG. 2 . The group information table 116 is not essential information in the present embodiment but information necessary to efficiently operate the system of the present embodiment.
[0039] FIG. 4 illustrates a software information table 114 in which a software ID 114 a and a software name 114 b of each software are associated with each other, and the software information table 114 is created by collecting software information from each operator terminal through an inventory information collecting function.
[0040] FIG. 5 illustrates an operation history information table 117 in which an operation result and an operation state on an input or an operation to each operator terminal 160 are received from each operator terminal and stored. The operation history information table 117 includes an operation ID 117 a which is a number used to identify each record in the table, a user ID 117 b of the operator, a software 117 c (the software ID 114 a illustrated in FIG. 4 ) being activated, software 117 d (a software ID corresponding to a topmost screen in a hierarchy of an operation screen) being used (activated) at the forefront, an operation period of time 117 e (as a unit of an operation period of time, “s” indicates a second, “m” indicates a minute, and “h” indicates a hour), an operation timing 117 f (an operation start timing), and an operation result 117 g (“OK” or “NG”).
[0041] FIG. 6 illustrates an analysis information table 115 dynamically generated according to an operation of each operator terminal 160 , and data of the analysis information table 115 is updated at certain time intervals. The analysis information table 115 includes a table (a) storing information related to software being activated, a table (b) storing information related to software being used at the forefront, and a table (c) storing information related to an operation timing.
[0042] The table (a) includes an operation ID 115 a - 1 which is a number used to identify each record in the table, a user ID 115 a - 2 of the operator, software IDs 115 a - 3 to 115 a - 8 associated with the operation, and an operation result 115 a - 9 .
[0043] The table (b) includes an operation ID 115 b - 1 which is a number used to identify each record in the table, a user ID 115 b - 2 of the operator, software IDs 115 b - 3 to 115 b - 8 associated with the operation, and an operation result 115 b - 9 .
[0044] The table (c) includes an operation ID 115 c - 1 which is a number used to identify each record in the table, a user ID 115 c - 2 of the operator, operation timings 115 c - 3 to 115 c - 6 of the terminal, and an operation result 115 c - 7 .
[0045] The tables (a), (b), and (c) of the analysis information table 115 is created based on the operation history information table 117 of FIG. 5 . The operation results 115 a - 9 , 115 b - 9 , and 115 c - 7 are based on the operation result 117 g of the operation history information table 117 , that is, “1” is stored in when the operation result is “OK,” and “−1” is stored when the operation result is “NG.” In the software IDs 115 a - 3 to 115 a - 8 of the table (a), “1” is stored for software being activated, and “0” is stored for software being not activated. In the software IDs 115 b - 3 to 115 b - 8 of the table (b), “1” is stored for software being used at the forefront, and “0” is stored for other software. In the operation timings 115 c - 3 to 115 c - 6 of the table (c), “1” is stored in a time zone including a time at which the terminal 160 is operated, and “0” is stored in the other time zones.
[0046] FIG. 7 illustrates an analysis result table 118 which is dynamically generated according to an operation of each operator terminal 160 , and data of the analysis result table 118 is updated at certain time intervals. The analysis result table 118 includes a table (a) storing information related to software being activated, a table (b) storing information related to software being used at the forefront, a table (c) storing information related to an average of operation periods of time, and a table (d) storing information related to an operation timing.
[0047] The table (a) stores information related to software being activated, and includes a department 118 a - 1 to which the operator belongs, a title 118 a - 2 of the operator, an occupational category 118 a - 3 of the operator, and software IDs 118 a - 4 to 118 a - 9 associated with the operator's operation. A regression coefficient value of each software obtained by, for example, regression analysis which will be described later is stored in each of columns corresponding to the software IDs 18 a - 4 to 118 a - 9 .
[0048] The table (b) stores information related to software being used at the forefront, has the same configuration as the table (a), and includes a department 118 b - 1 to which the operator belongs, a title 118 b - 2 of the operator, an occupational category 118 b - 3 of the operator, and software IDs 118 b - 4 to 118 b - 9 associated with the operator's operation. A regression coefficient value related to whether each software is activatable which is obtained by, for example, regression analysis which will be described later is stored in each of columns corresponding to the software IDs 118 b - 4 to 118 b - 9 .
[0049] The table (c) stores information related to an average of operation periods of time, has the same configuration as the table (a), and includes a department 118 c - 1 to which the operator belongs, a title 118 c - 2 of the operator, an occupational category 118 c - 3 of the operator, and software IDs 118 c - 4 to 118 c - 9 associated with the operator's operation. An average of operation periods of time of each software is stored in each of columns corresponding to the software IDs 118 c - 4 to 118 c - 9 .
[0050] The table (d) stores information related to an operation timing, has the same configuration as the table (a), and includes a department 118 d - 1 to which the operator belongs, a title 118 d - 2 of the operator, an occupational category 118 d - 3 of the operator, and software IDs 118 d - 4 to 118 - 9 associated with the operator's operation. A regression coefficient value related to whether each software is activatable which is obtained by, for example, regression analysis which will be described later is stored in each of columns corresponding to the software IDs 118 d - 4 to 118 d - 9 .
[0051] The tables (a), (b), (c), and (d) are created based on the analysis result based on the analysis information table 115 of FIG. 6 .
[0052] Information obtained by extracting a corresponding row (record) in each of the four tables (a) to (d) of FIG. 7 for each operator terminal 160 is “timing determination information” which will be described later, and the “timing′ determination information” is transmitted from the management server 100 to each operator terminal 160 .
[0053] For “software being activated” of the table (a) and “software being used at the forefront” of the table (b), software having a high numerical value (regression coefficient) is determined to be high in a probability that the operator will operate when the software is being activated or used at the forefront (the regression coefficient has a value between −1 to +1). Further, when an analysis method other than the regression analysis is used, there are cases in which software having a low numerical value is high in a probability that the operator will operate the software. In other words, it is desirable to obtain a probability that the operator will operate or a normalized probability, and any other analysis method may be used. For “operation timing” of the table (d), a time zone having a high numerical value is determined to be high in a probability that the operator will operate.
[0054] “Average of operation periods of time” of the table (c) is used to determine whether it is possible to perform an operation using “software being used at the forefront” of the table (b).
[0055] In the analysis result table 118 of FIG. 7 , each data is grouped according to the department, the title, and the occupational category of the operator and analyzed, and the result is illustrated, but without performing grouping, analysis may be performed of each operator, or analysis may be performed by regarding all data as one group. In this case, the administrator may select a criterion (a criterion such as whether grouping is performed as in FIG. 7 , whether grouping is performed for each operator, or whether all data are regarded as one group) related to grouping on a screen in advance.
[0056] (Explanation of Process)
[0057] FIG. 8 illustrates an outline of a process according to the present embodiment.
[0058] In the system in which the management server 100 is connected with the plurality of operator terminals 160 via the network 150 , the following process is performed. A diagram number in parentheses ( ) is a number of a diagram illustrating the flow of corresponding process.
[0059] (1) The management server 100 receives content of an operation which is requested to be performed by the operator of the terminal 160 as the administrator performs a screen operation through the I/O device 120 . The content of an operation to be requested is transmitted to each terminal 160 ( FIG. 9 ).
[0060] (2) Each terminal 160 executes a terminal operation based on the operation content transmitted from the management server 100 ( FIG. 10 and FIG. 11 ).
[0061] (3) The terminal 160 controls a display timing of a dialogue based on timing determination information which will be described later during the process ( 2 ), and transmits the operation result to the management server 100 , and the management server 100 stores the received operation result ( FIG. 12 and FIG. 13 ).
[0062] (4) The management server 100 performs analysis (regression analysis) on the received operation result, generates (new) timing determination information based on the analysis result, and transmits the generated timing determination information to each terminal 160 . Each terminal 160 updates timing determination information which is referred to in the process ( 3 ) based on the received (new) timing determination information ( FIG. 14 ).
[0063] The above process is repeated at certain time intervals.
[0064] FIG. 9 is a flowchart illustrating a process of the management program 111 of the management server 100 , and illustrates a process of receiving a screen operation of the administrator and requesting the operator terminal to perform an operation (( 1 ) of FIG. 8 ).
[0065] In response to an operation performed through the I/O device 120 by the administrator, the management program 111 acquires information for requesting the operator terminal 160 to perform an operation ( 901 ). Specifically, the information to be acquired includes an operation execution timing, operation content, and an operation execution time limit when an execution timing is not “immediate execution.”
[0066] FIGS. 15 , 16 , and 17 illustrate exemplary screen displays corresponding to the administrator's operation.
[0067] Referring to FIG. 15 , a device list in which various apparatuses (terminals) are associated with information related to operators using the apparatuses (terminals) is displayed, and so the administrator selects an apparatus (the terminal 160 ) which is to be requested to perform an operation from the device list. Further, when “operation menu” at the lower right of FIG. 15 is designated, an operation list (for example, menu content of software distribution and user information input) is displayed as illustrated in FIG. 16 , and thus the administrator selects an operation content from the list. Further, when “software distribution” is selected in the operation content, a screen used to designate a software distribution timing is displayed as illustrated in FIG. 17 , and thus the administrator inputs an execution timing. FIG. 17 illustrates an example in which “execution according to operator's timing (of terminal 160 )” is selected as an execution timing, a time limit is configured, and a date and time of a specific time limit is input.
[0068] The description continues with reference back to FIG. 9 . It is determined whether an execution timing designated according to the administrator's operation as illustrated in FIG. 17 is “immediate execution” ( 902 ), the process proceeds to step 904 when the execution timing is “immediate execution”, and timing determination information of corresponding group is acquired from the analysis result table 118 illustrated in FIG. 7 for each terminal when the execution timing is “execution according to operator's timing” ( 903 ). In other words, timing-related information of each group acquired most recently is acquired.
[0069] The management program 111 determines whether the operation content designated by the administrator's operation as illustrated in FIG. 16 is software distribution ( 904 ), acquires a distribution target program when the operation content is the software distribution ( 905 ), and transmits the following content to the terminal selected as illustrated in FIG. 15 as an operation command (operation content of FIG. 8 ) ( 906 ). In other words, a distribution target program installer, timing determination information (when present), and a time limit (when present) are transmitted as the operation command.
[0070] When the operation content is determined to be a user information input request in step 904 , the following content is transmitted to the terminal 160 selected as illustrated in FIG. 15 as the operation command ( 907 ). In other words, the user information input request, the timing determination information (when present), and a time limit (when present) are transmitted as the operation command.
[0071] FIG. 10 is a flowchart illustrating a process of the management client program 171 at the operator terminal 160 , and is a diagram illustrating a process (( 2 ) and ( 3 ) of FIG. 8 ) of executing an operation requested from the management program 111 .
[0072] The management client program 171 receives the operation command (operation content) from the management program 111 of the management server 100 ( 1001 ).
[0073] The management client program 171 determines whether there is timing determination information in the operation command ( 1002 ). When there is no timing determination information, the process proceeds to step 1006 , but when there is timing determination information, it is determined whether content of the operation designated by the administrator has to be performed using the timing determination information ( 1003 ). The details of this step will be described later with reference to FIG. 12 . It is determined whether the determination result “execution OK” or “execution NG” ( 1004 ). The management client program 171 proceeds to next step 1006 when the determination result is “execution OK,” and executes step 1003 again after being on standby for about 5 minutes (it is about 5 minutes when a terminal operation is assumed, but a period of time is arbitrary) when the determination result is “execution NG.”
[0074] Although not illustrated, a time limit is configured in the operation command, and when the determination result is “execution NG” and the time limit is exceeded if it is on standby for about 5 minutes, “execution OK” is determined in step 1004 for timing determination.
[0075] The management client program 171 determines whether the content of the operation designated by the administrator is “software distribution” or “user information input request” as illustrated in FIG. 16 ( 1006 ). When the operation content is “software distribution,” the distribution target program installer included in the operation command is activated in response to Confirmation of the operator ( 1007 ), but when the operation content is “user information input request,” a user information input dialogue is displayed ( 1008 ). FIG. 18 illustrates an exemplary screen of the operator terminal 160 when the operation command in which the operation content is “software distribution” is received from the management program 111 .
[0076] After the operator executes the operation content, as illustrated in FIG. 11 , the management client program 171 determines the operation result ( 1101 ), and executes any one of the following three processes according to the operation result.
[0077] When the operation result is “execution,” a notification of the following result is given to the management program 111 . In other words, an operation result (OK), information of software being used at the forefront, an operation period of time (of software being used at the forefront), information of software being activated, and an operation timing are notified of ( 1102 ).
[0078] When the operation result is refusal, a notification of the following result is given to the management program 111 . In other words, an operation result (NG), information of software being used at the forefront, an operation period of time (of software being used at the forefront), information of software being activated, and an operation timing are notified of ( 1103 ).
[0079] When there is no operation for about 5 minutes, a notification of the following result is given to the management program 111 . In other words, an operation result (NG), information of software being used at the forefront, an operation period of time (of software being used at the forefront), information of software being activated, and an operation timing are notified of ( 1104 ), and thereafter, an operation result is determined again ( 1101 ).
[0080] FIG. 12 is a flowchart illustrating a process ( 1003 of FIG. 10 ) of determining whether a dialogue display (operation content) has to be executed based on the timing determination information through the management client program 171 .
[0081] The management client program 171 collects operation log information of the terminal 160 including the following information from the terminal 160 being operated. In other words, information of software being used at the forefront, an operation period of time (of software being used at the forefront), and information of software being activated are collected ( 1201 ).
[0082] The management client program 171 calculates a value used to decide whether it is possible to perform an operation using information of software being activated and the timing determination information (associated with software being activated) (calculation 1 ) ( 1202 ).
[0083] The management client program 171 determines whether a result of the calculation 1 is a certain value (0.5) or more ( 1203 ). When the result of the calculation 1 is the certain value or more, the process proceeds to step 1210 , but when the result of the calculation 1 is the certain value or less, the management client program 171 calculates a value used to decide whether it is possible to perform an operation using a current time and a timing determination information (associated with an operation timing) (calculation 2 ) ( 1204 ).
[0084] The management client program 171 determines whether a result of the calculation 2 is a certain value (0.5) or more ( 1205 ). When the result of the calculation 2 is the certain value or more, the process proceeds to step 1210 , but when the result of the calculation 2 is the certain value or less, the management client program 171 calculates a value used to decide whether it is possible to perform an operation using information of software being used at the forefront and timing determination information (associated with software being used at the forefront) (calculation 3 ) ( 1206 ).
[0085] The management client program 171 determines whether a result of the calculation 3 is a certain value (0.5) or more ( 1207 ). When the result of the calculation 3 is the certain value or more, the process proceeds to step 1208 , but when the result of the calculation 3 is the certain value or less, it is determined that it is difficult to perform an operation (execution NG), and then the process ends ( 1211 ).
[0086] When the result of calculation 3 is the certain value or more, the management client program 171 acquires an average period of time from the timing determination information (average of operation periods of time) ( 1208 ), and determines whether an average period of time or more has elapsed ( 1209 ), determines that it is possible to perform an operation (execution OK) when an average period of time or more is determined to have elapsed ( 1210 ), and determines that it is difficult to perform an operation (execution NG) when an average period of time or more is determined not to have elapsed ( 1211 ), and then the process ends.
[0087] FIG. 13 is a flowchart illustrating a process of storing information (operation result) received from the operator terminal 160 through the management program 111 of the management server 100 .
[0088] The management program 111 receives an operation history corresponding to the user ID 117 b of the operator illustrated in FIG. 5 from the operator terminal 160 ( 1301 ). The operation history to be received includes an operation result (OK or NG), information of software being used at the forefront, an operation period of time (of software being used at the forefront), information of software being activated, and an operation timing. The received operation history information is inserted into the operation history information table ( 1302 ).
[0089] FIG. 14 is a flowchart illustrating a process (( 4 ) of FIG. 8 ) of analyzing the operation history information table at the frequency of once per day (once per day is a rough idea, and the frequency is arbitrary) and newly creating the timing determination information through the management program ill of the management server 100 .
[0090] The management program 111 creates the analysis information table 115 illustrated in FIG. 6 based on the operation history information table 117 illustrated in FIG. 5 ( 1401 ). Then, the management program 111 extracts a group from the group information table 116 illustrated in FIG. 3 ( 1402 ).
[0091] The management program 111 executes the following steps 1404 to 1407 on all combinations of “department=x,” “title=y,” and “occupational category=z.”
[0092] Information of the user (the user ID) belonging to a group (for example, a group of a department ID=1, a title ID=1, and an occupational category ID=1) is extracted from the analysis information table 115 ( 1404 ). Regression analysis is executed to obtain a regression coefficient ( 1405 ). The details of a calculation in the regression analysis will be described later.
[0093] The regression coefficient obtained in step 1405 is stored in the analysis result table 118 illustrated in FIG. 7 ( 1406 ). Further, an average of operation periods of time of each software is stored in the analysis result table 118 illustrated in FIG. 7 in association with software being used at the forefront ( 1407 ).
[0094] Here, a process of creating the timing determination information by the regression analysis will be described.
[0095] When the number of users is n and the number of software is P, a relation between an operation result and whether a program is activatable/usable is expressed by Formula (1):
[0000] [Formula 1]
[0000] ( i= 1 to n, n is the number of users, and P is the number of software) (1)
[0096] W(i): an operation result of a user i (which it is 1 in when it is OK and −1 when it is NG),
[0097] ak: a regression coefficient of software k (a correlation coefficient),
[0098] x k (i): whether the user i can activate or use the software k (0/1)
[0099] Formula (1) includes a regression coefficient of software representing a correlation between an operation result and the software.
[0100] In order to optimize each regression coefficient, an optimal value of each regression coefficient is obtained from a condition in which a square error average σ of an actual operation result and whether a program is activatable/usable is minimum as in Formula (2).
[0000] Based on δσ/δak=0, (k=1 to P), among {ak} a large factor (ak) is calculated. → software having large influence can be understood. ({ak} is the timing determination information). [Formula 2]
[0101] It is understood that as the regression coefficient value obtained as described above increases, influence of software corresponding to the value on an operation result increases.
[0102] Using the regression coefficient of each soft obtained as described above and a flag (which is 1 when it is in use and −1 when it is not in use) of software being used (activated), the calculation of Formula (3) is performed to obtain a value (−1 and +1) representing whether it is possible to perform an operation, and it is determined whether it is possible to perform an operation in step 1210 or 1211 of FIG. 12 based on the obtained value.
[0000] Y: a value (−1 to +1) representing whether it is possible to perform an operation X1 to X6: a flag (which is 1 when it is in use and −1 when it is not in use) of software being used A to F: a value (the regression coefficient (ak)) of the timing determination information (software being used) [Formula 3]
[0103] For example, when software being used by the operator (“A department,” “manager,” and “administration”) is software 102 and 106 of FIG. 7( b ), the value representing whether it is possible to perform an operation, that is, Y is 0.8 (=−0.6*0+0.4*1+0*0+0*0+0.1*0+0.4*1) which is larger than the certain value (0.5), and thus it is determined that it is possible to perform an operation.
[0104] When it is determined whether it is possible to perform an operation at a certain operation timing (time zone), a time zone is used instead of a flag of software being used. As an operation timing, a time zone Y k (i) is used instead of X k (i). For example, as illustrated in FIG. 6( c ), y 1 (i) is assumed to be 9:00 to 12:00, y 2 (i) is assumed to be 12:00 to 15:00, y 3 (i) is assumed to be 15:00 to 18:00, and y 4 (i) is assumed to be 18:00 to 21:00 (the number P of time zones is 4).
REFERENCE SIGNS LIST
[0000]
100 management server
110 , 170 memory/HDD
111 management program
112 distribution target program installer
113 user information
114 software information
115 analysis information
116 group information
117 operation history information
118 analysis result
120 , 180 I/O device
130 , 192 CPU
140 , 191 NIC
160 operator terminal
150 network
171 management client program
172 application A
173 application B
174 distributed program
175 timing determination information | A method of determining whether a dialogue is displayable includes recording a previous software use state in a terminal which has been responded to an input operation to the terminal, comparing the recorded previous software use state with a current software use state in the terminal, and displaying an input operation dialogue according to a result of the comparison. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Stage of International Application No. PCT/DE2003/003546 filed Oct. 25, 2003, which claims priority to German Patent Application No. DE 102 51 849.1 filed on Nov. 7, 2002. The disclosures of the above applications are incorporated herein by reference.
TECHNICAL FIELD
The invention relates to a light guide for lighting vehicles, preferably motor vehicles.
BACKGROUND
There are known light guides essentially rectangular in shape and comprising lighting means in the form of LEDs arranged in series side-by-side on one narrow end. With them, light is fed into the light guide, and reflected from reflecting surfaces towards the light exit side. A uniform illumination is thus not assured.
The object of the invention is to configure the generic light guide such that an optimum illumination of the light guide is assured with simple design conformation.
This object is accomplished according to the invention, in the light guide, of the present invention.
SUMMARY OF THE INVENTION
In the light guide according to the invention, the reflecting surfaces, viewed in the direction of the rays, are offset from each other. The reflecting surfaces are so arranged that, viewed in the direction of the rays, they adjoin each other essentially without gaps. Thus, between the individual reflecting surfaces, no shadows are cast, so that the light emitted by the lighting means is optimally utilized. As a result of the configuration according to the invention, the light exit side is fully illuminated.
Other features of the invention will appear from the additional claims, the description and the drawings.
DESCRIPTION OF THE DRAWINGS
The invention will be illustrated in more detail in terms of an embodiment represented in the drawings by way of example. In the drawings,
FIG. 1 shows a view of a light guide according to the invention, its light guide parts being represented separately,
FIG. 2 shows the light guide of FIG. 1 in perspective representation,
FIG. 3 shows the light guide in a view in the direction of the arrow III in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The light guide 1 is intended for lighting of motor vehicles, and consists in known manner of light-conducting material. The light guide 1 has a rectangular outline in top view, with two plane side walls 2 , 3 parallel to each other. On their long side, the side walls 2 , 3 are connected to each other by a light exit surface 4 , having a rectangular outline in top view.
The light guide 1 is made in one piece, but consists of two light guide parts 5 and 6 each having a rectangular shape in top view. The light guide parts 5 , 6 are essentially of like configuration, but arranged lying rotated at 180° to each other. The two light guide parts 5 , 6 have a common light exit surface 4 . The light guide part 5 is provided at one end with a plane face 7 , extending over the entire width and height of the light guide part 5 , to which a lighting means 8 , preferably an LED, is connected. From this face 7 on out, the height of the light guide part 5 decreases in the direction of the opposed face 9 , which extends over the entire width of the light guide part 5 .
The other light guide part 6 likewise comprises a face 10 , rectangular in the view, which like the face 7 is of plane configuration, and to which an additional lighting means 11 , preferably an LED, is connected. The height of the light guide part 6 diminishes from this face 10 on as far as the opposed face 12 . It is of but little height, but it extends over the entire width of the light guide part 6 . As may be seen in FIG. 2 , the faces 7 , 12 and 9 , 10 each lie in a common plane. The faces 7 , 10 , like the faces 9 , 12 , lie diagonally opposed to each other.
The side of the two light guide parts 5 , 6 opposed to the light exit surface 4 is provided with reflecting surfaces 13 , 14 , on which the light emitted from each lighting means 8 , 11 is reflected to the light exit surface 4 . The reflecting surfaces 13 , 14 are arranged so inclined relative to the direction of the rays that the rays of light exit from the light exit surface 4 at an angle of 90°. Depending on the application, it is of course possible to arrange the reflecting surfaces 13 , 14 inclined at other angles, so that the light rays will exit the light exit surface 4 at angles other than 90°.
The reflecting surfaces 13 , 14 are each plane and extend, as FIG. 2 shows, over the width of the light guide part 5 , 6 in question. The reflecting surfaces of the light guide part 5 are moreover inclined in opposed direction to the reflecting surfaces 14 of the light guide part 6 . In this embodiment by way of example, the reflecting surfaces 14 of the light guide part 6 lie parallel to each other.
The reflecting surfaces 13 each adjoin oblique surfaces 15 inclined in opposition to them, which in turn adjoin, at acute angles, side surfaces 16 lying perpendicular to the light exit surface 4 . These side surfaces 16 adjoin the respective reflecting surfaces 13 at obtuse angles. The oblique surfaces 15 and the side surfaces 16 form the side walls of projections 14 , triangular in cross-section.
In like manner, the reflecting surfaces 14 of the light guide part 6 adjoin side surfaces 18 lying perpendicular to the light exit surface 4 at obtuse angles, which surfaces 18 in turn pass over into oblique surfaces 19 at acute angles. They adjoin the reflecting surfaces 14 . The side surfaces 18 and the oblique surfaces 19 form side walls of triangular projections 20 , triangular in cross-section.
The reflecting surfaces 13 , as may be seen in FIGS. 1 and 2 , lie at gap to the reflecting surfaces 14 . Accordingly, the width, measured in the direction of the rays, of the reflecting surfaces 13 is equal in size to the width, measured in the same direction, of the oblique surfaces 19 . Conversely, the width, measured in the direction of the rays, of the reflecting surfaces 14 , is equal to the width of the oblique surfaces 15 , measured in the same direction.
The reflecting surfaces 13 , arranged one behind another, of the light guide part 5 , from the face 7 on, have increasingly smaller distance from the light exit surface 4 . The reflecting surfaces 14 of the light guide part 6 , starting from the face 10 of this light guide part 6 , also have increasingly smaller distance from the light exit surface 4 . The reflecting surface 13 ′ of the light guide part 5 , located at half-length of the light guide 1 , passes over into the oblique surface 19 ′ of the light guide part 6 , with which it lies in a common plane. From this common surface 13 ′, 19 ′ on, in the direction of the face 7 , the light guide part 5 outreaches the light guide part 6 , while conversely, from the common surface 13 ′, 19 ′ on, towards the face 10 , the light guide part 6 outreaches the light guide part 5 . The light guide part 5 , 6 , in its respective overreaching portion, has a plane side wall 21 , 22 parallel to the side wall 2 , 3 of the light guide 1 .
On the basis of the stepped arrangement of the reflecting surfaces 13 , 14 and their offset arrangement to each other, it is brought about that the rays emitted by the LEDs 8 , 11 are reflected at the reflecting surfaces 13 , 14 to the light exit surface 4 . Thus, each light guide part 5 , 6 generates luminous bands 23 , 24 at the reflecting surfaces 13 , 14 , of which three luminous bands are represented in FIG. 1 . The luminous bands 23 , 24 of each light guide part 5 , 6 lie at a distance from each other. Owing to the offset arrangement of the reflecting surfaces 13 , 14 to each other, the luminous band 24 , in side view as in FIG. 1 , shines into the area between luminous bands 23 of the light guider part 5 . This, seen in side view, generates a continuous luminous field.
The reflecting surfaces 13 , 14 are each so arranged that, seen in the direction of the rays, they adjoin each other. This means that the edge 25 , anterior in the direction of the rays, of the reflecting surface 13 adjoining the face 7 , viewed in the direction of the rays, lies at the same level as the margin 25 , posterior in the direction of the rays, of the next reflecting surface 13 . In this way, the reflecting surfaces 13 of the light guide part 5 and the reflecting surfaces 14 of the light guide part 6 are arranged one behind another.
Since the two lighting means 8 , 11 are provided at the two ends of the light guide 1 , an optimal luminous yield results, with compact structure of the light guide 1 . The light is so fed into the light guide 1 that the light rays in the light guide 1 are propagated almost parallel. The stair-like reflecting surfaces 13 , 14 with the projections 17 , 20 located between them guide the light rays in the manner described to the light exit surface 4 . The subdivision of the deflecting optics into contrary profiles makes possible a very uniform illumination of the light exit surface 4 . It may be additionally provided with scattering and/or refracting elements to achieve a desired distribution of light. In the embodiment by way of example ( FIG. 3 ), the light exit surface 4 is provided with cushion-shaped optics 27 , immediately adjoining each other by way of the said area of the light exit surface 4 .
The two light sources 8 , 11 emit light of like color. Alternatively, it is possible for the two sources 8 , 11 to emit light of different colors. Then the light exit surface 4 , owing to the arrangement of the reflecting surfaces 13 , 14 as described, is illuminated checkerboard-fashion by the color in question.
It is also possible, instead of the two light guide parts 5 , 6 , to provide additional light guide parts, in that case arranged each rotated 180° to the respective neighboring light guide parts. | The present invention relates to a light guide for lighting vehicles, preferably motor vehicles. Light rays emitted from the light source of the light guide are reflected off of reflecting surfaces toward a light exit surface. The reflected surfaces are arranged to allow full illumination of the light exit surface. | 5 |
BACKGROUND OF THE INVENTION
This invention relates generally to pivoting door arrangements and is particularly directed to a hinged door wherein the hinge mechanism is integrated with the door and its supporting structure.
Pivoting doors are frequently used in electronic apparatus to cover a control panel. This is particularly the case in consumer-type electronic products where the controls are frequently positioned behind a movable door in order to limit access to the controls as well as to improve the aesthetics of the electronic apparatus. Where the door is of the pivoting type, certain design and operating criteria are particularly desirable. For example, the door should be easily installed and inexpensively manufactured. Its pivotal mounting configuration should involve a minimal number of components all of which should be low in cost and of simple design. Thus, the use of springs, magnets or latches, as frequently encountered in the prior art, is highly undesirable from the standpoint of increased complexity and expense as well as reduced reliability. In addition, a separate hinge mechanism is undesirable since this too involves an additional component, or components, with the hinge itself requiring a separate installation procedure. The pivoting door in combination with its mounting arrangement should also be easily manipulated, structurally strong, and not easily broken. Finally, the door mounting arrangement should be capable of maintaining the door in both the full open and full closed positions in a stable manner and should provide for the self-closure of the door when it is oriented in an intermediate position.
The present invention provides a hinged door arrangement particularly adapted for a television control panel which possesses all of the aforementioned characteristics and is comprised of just two components--a pivoting door and a support panel to which it is easily, yet securely mounted.
OBJECTS OF THE INVENTION
Accordingly, it is an object of the present invention to provide a hinged door particularly adapted for use in electronic control panels.
It is another object of the present invention to provide a hinged door arrangement wherein the hinge mechanism is integral with the door and its supporting structure.
Yet another object of the present invention is to provide a hinged door arrangement which is comprised of only two elements--the door and its supporting structure.
A further object of the present invention is to provide a hinged door construction without springs, magnets, latches, or a separate hinge mechanism.
A still further object of the present invention is to provide a pivoting door arrangement which biases the door to the closed position while allowing it to be easily opened and remain stably in the full open position.
Another object of the present invention is to provide a low cost hinged door arrangement having a minimum number components which is reliable, easily fabricated and easily assembled.
BRIEF DESCRIPTION OF THE DRAWINGS
The appended claims set forth those novel features which characterize the invention. However, the invention itself, as well as further objects and advantages thereof, will best be understood by reference to the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings, where like reference characters identify like elements throughout the various figures, in which:
FIG. 1 is a front view of a control panel to which a pivoting door may be mounted in accordance with the present invention;
FIG. 2 is a sectional view of the control panel of FIG. 1 without the door attached thereto taken along sight line 2--2 in FIG. 1;
FIG. 3 is a sectional view of a portion of the control panel shown in FIG. 1 taken sight line 3--3 therein;
FIG. 4 is a side view of the portion of the control panel illustrated in FIG. 3 taken along sight line 4--4 therein;
FIG. 5 is a sectional view of the portion of the control panel illustrated in FIG. 3 taken along sight line 5--5 therein;
FIG. 6 is a partial front view of a control panel with a door attached thereto in accordance with the present invention;
FIG. 7 a plan view of a door capable of being pivotally mounted to the control panel of FIGS. 1 and 2 in accordance with the principles of the present invention;
FIG. 8 is a sectional view of a portion of the door illustrated in FIG. 7 taken along sight line 8--8 therein; and
FIG. 9 is a lateral section view of a door pivotally mounted to and supported by a panel as shown in FIG. 6 illustrating the door in several different orientations taken along sight line 9--9 therein.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a front view of a control panel 10 to which a door may be pivotally coupled in accordance with the principles of the present invention. FIG. 2 is a sectional view of the control panel 10 of FIG. 1 taken along sight line 2--2 therein.
The control panel 10 is preferably a unitary structure comprised of a high strength, molded plastic. The control panel 10 includes a plurality of mounting tabs 12 positioned around the periphery thereof. Each mounting tab includes one or more apertures 14 through which a coupling pin, such as a threaded screw, may be inserted for securely mounting the control panel 10 on a support structure such as the cabinet of a consumer-type electronic apparatus, e.g., a television receiver. When thus positioned upon an appropriate supporting structure, the portion of the control panel 10 shown in FIG. 1 would be directed outwardly from the apparatus. Thus, in referring to FIG. 2, the outer portion of the control panel 10 as used herein is on the left of the figure, while the inner portion of the control panel is toward the right. In addition, in referring to right and left hand portions of the control panel as well as of the door (not shown in FIGS. 1 or 2), such designations are taken with the control panel viewed from the rear or as viewed when looking outward from the apparatus to which it is mounted.
The control panel 10 includes an upper, recessed portion 16 within which is located a generally rectangular aperture 18. The aperture 18 within the control panel 10 is adapted to receive a keyboard panel (not shown) having a plurality of keys by means of which user entries such as channel selection may be made.
The control panel 10 also includes a generally flat, lower recessed portion 20 which may include a plurality of control knob apertures 22 adapted to receive a respective rotary control knob (not shown). These controls permit a user to provide additional control inputs to the television receiver as indicated in the figure. Referring specifically to FIG. 2, extending from a rear portion of the control panel 10 are a plurality of mounting brackets 40, 42 and 44, each typically including a threaded aperture therein. Mounting brackets 42 and 44 may be used for securely positioning a channel select keyboard (not shown) within the rectangular aperture 18 in the upper recessed portion 16 of the control panel 10. Similarly, a mounting bracket, or brackets, 40 positioned immediately aft of the lower recessed portion 20 of the control panel 10 may be used for mounting a control module (not shown) from which extend various rotary control knobs which may each be positioned within a respective control knob aperture 22. These control modules may be maintained in position upon respective mounting bracket by conventional means such as a threaded screw. The control panel 10 as thus far described is generally conventional in construction and configuration, with the various features of the present invention described in detail in the following paragraphs.
Positioned on lower, lateral portions of the control panel 10 and extending forwardly therefrom are left and right mounting arms 24, 28. Each of the left and right mounting arms 24, 28 includes a respective mounting stud 26, 30 positioned adjacent its distal end and extending outwardly from an outer, lateral portion thereof. Each of the left and right mounting arms 24, 28 is provided with a certain degree of flexibility and resilience to facilitate the positioning of a door (not shown) thereon as described in detail below.
Also positioned on a lower portion of the control panel 10 in the lower recessed portion 20 thereof are left and right apertures 32, 34. The left and right apertures 32, 34 are respectively positioned immediately adjacent to and inwardly toward the center of the control panel 10 from the left and right mounting arms 24, 28. Positioned over a respective left and right aperture 32, 34 and securely coupled to the lower recessed portion 20 of the control panel 10 are left and right resilient biasing arms 36, 38. The left and right resilient biasing arms 36, 38 are securely coupled at the upper, proximal ends thereof to the control panel 10 and extend forwardly and downwardly from the control panel's lower recessed portion 20. Each of the left and right resilient biasing arms 36, 38 is comprised of a flexible, resilient material which allows the biasing arm to be deflected toward a respective aperture immediately to the rear thereof by force applied thereto and to resume its initial, forward position when the applied force is removed. Each of the left and right resilient biasing arms 36, 38 engages a portion of the door (not shown) for urging it to a closed position as described in detail below. In a preferred embodiment, the control panel 10 as well as the left and right mounting arms and studs and left and right resilient biasing arms 36, 38 are formed of a unitary structure such as a high strength molded plastic.
Referring to FIG. 3, there is shown a sectional view of a portion of the control panel 10 of FIG. 1 taken along sight line 3--3 therein. A lateral view of the sectional view of a portion of the control panel 10 of FIG. 3 is shown in FIG. 4. As shown in FIGS. 3 and 4, the left mounting arm 24 includes a generally cylindrical-shaped mounting stud 26 extending outwardly from a lateral portion thereof adjacent to its distal end. As stated above, the left mounting arm 24 is preferably comprised of a flexibly resilient material allowing the mounting arm to be deflected inwardly, or to the left as shown in FIG. 3, as indicated by the arrow therein. This facilitates the positioning of a lateral portion of the door (not shown) on the mounting arm by inserting the mounting stud 26 in an aperture within the door as described in detail below. Also as stated above, the left resilient biasing arm 36 is coupled to and extends from the lower recessed portion 20 of the control panel 10. The left resilient biasing arm 36 extends downwardly as well as outwardly from the lower recessed portion 20 of the control panel and includes a lower distal end 36a as well as a forward projection 36b on a front surface thereof. The left resilient biasing arm 36 is also comprised of a flexibly resilient material allowing the biasing arm to be deflected rearwardly by a force applied thereto and to resume its initial position following removal of the applied force. The direction of deflection of the left resilient biasing arm 36 is indicated by the arrow in FIG. 4. It is to be noted that this description of the structure and operation of the left mounting arm 24 and the left resilient biasing arm 36 applies equally well to the right mounting arm 28 and the right resilient biasing arm 38.
Additional details of the mounting arms and resilient biasing arms are shown in FIG. 5 which is a sectional view taken along sight line 5--5 in FIG. 3 through the left resilient biasing arm 36 in a direction toward the right mounting arm 28. Positioned immediately adjacent to the left aperture 32 and the left resilient biasing arm 36 is a left reinforcing rib 46. A similar arrangement is provided on the right-hand portion of the control panel 10 where right reinforcing rib 48 is positioned immediately adjacent to the right aperture 34 and the right resilient biasing arm 38 and toward the center of the control panel. Each of the left and right reinforcing ribs 46, 48 extends forwardly of the lower recessed portion 20 of the control panel and is generally triangular in shape.
Referring to FIG. 6, there is shown a door 50 positioned upon the control panel 10 so as to cover the lower recessed portion thereof in accordance with the present invention. An outer, upper portion of the door 50 is provided with gripping means, or a handle, 52 by means of which the door may be grasped and pivotally displaced as described below.
Referring to FIG. 7, there is shown the inner portion of the door 50. As shown in FIG. 7 the door 50 is oriented such that the upper portion of the door when it is in the closed position is shown in the lower portion of the figure and the lower portion of the door, when closed, is shown in the upper portion of the figure. The inner, upper portion of the door 50 includes an upper rib 54 which extends the length of the door and to which the handle 52 is securely connected. The upper rib 54 facilitates the positioning of the handle 52 on the door 50 and reinforces its mounting thereon. Lateral portions of the door are defined by left and right ribs 58, 74 which extend from the inner surface of the door. Located in lower portions of the left and right ribs 58, 74 are respective left and right mounting apertures 60, 68. Located immediately inwardly of the apertures 60, 68 in the respective lateral ribs of the door are left and right recessed portions 62, 66 on the inner surface of the door. Extending between the left and right recessed portions 62, 66 and along the lower edge of the door 50 is a lower rib 55. Extending outward from the lower rib 55 adjacent respective ends thereof are left and right tabs 56, 64. Additional details of the configuration of the lower, left-hand portion of the door 50 can be seen in the sectional view of FIG. 8 taken along sight line 8--8 in FIG. 7.
There is provided on the inner surface of the door 50 a door stop 70 which is positioned upon the door so as to be aligned with and to contact a striker tab 72 on the panel's lower recessed portion 20 when the door is closed. The door stop 70 is preferably comprised of a soft, resilient material in order to eliminate noise arising from the closure of the door with an inner portion of the door contacting a forward portion of the support panel.
The assembly and operation of the hinged door of the present invention will now be described in detail in terms of the figures discussed above as well as FIG. 9 which shows the door in the fully opened, fully closed, and intermediate positions. In FIG. 9, a sectional view of the door 50 in the fully open position is shown in solid lines wherein the door is oriented generally horizontally. In this position, the tabs of the door are oriented generally vertically as shown for the case of the right tab 64 in the figure. The door 50 is attached to the control panel 10 by inserting one of the mounting studs on a mounting arm of the control panel into a mounting aperture in a corresponding lateral rib of the door. The other mounting arm is then displaced inwardly toward the center of the control panel in order to permit its mounting stud to be inserted into the other mounting aperture in the opposite, facing lateral rib of the door. Thus, in order to facilitate installation and removal of the door 50 from the control panel 10 each of the left and right mounting arms 24, 28 is preferably comprised of a resiliently flexible material. With each of the mounting studs of the control panel inserted within a respective mounting aperture of the door, the door may be pivotally displaced about an axis defined by the mounting studs 26, 30. With the door 50 oriented in the full open position as shown in solid lines in FIG. 9, counterclockwise rotation of the door is prevented by engagement of the lower, inner surface of the door defined by the left and right recessed portions 62, 66 thereof with respective lower, distal portions of the left and right mounting arms 24, 28. The left and right recessed portions 62, 66 of the door 50 further provide clearance for the respective distal ends of the left and right mounting arms 24, 28 to permit the door to be rotated about the aforementioned axis located adjacent the distal ends of the mounting arm and defined by the aforementioned mounting studs without the inner surface of the door contacting the distal ends of these mounting arms.
As the door 50 is rotated in a clockwise direction about an axis defined by the mounting stud 30 as shown in FIG. 9, the tabs extending from the inner surface of the door engage a respective forward projection of a resilient biasing arm. This is shown in FIG. 9 for the case of the right tab 64 and the forward projection 36b of the right resilient biasing arm 38. In this position, the door 50 is oriented at an inclined angle between the full open and full closed positions. If at this point the door is let go, it will fall under the influence of gravity and return to the full open position. However, if the door 50 is further displaced toward the closed position, the distal end of the right tab 64 will further engage the forward projection 36b of the right resilient biasing arm 38 deflecting the biasing arm rearward as shown in dotted line form in the figure. When the distal end of the right tab 64 travels beyond the forwardmost point of the forward projection 36b on the right resilient biasing arm 38, the resilience of the biasing arm urges it forward so as to bias the right tab 64 downward and urge the door 50 in a clockwise direction of rotation. With the door in a generally vertical orientation and in the fully closed position, the distal end of the right tab 64 is positioned beneath the forward projection 36b on the right resilient biasing arm 38 which maintains the tab in this position and the door in the closed configuration. By pulling an upper portion of the door 50 away from the control panel 10, the distal end of the right tab 64 will displace the right resilient biasing arm 38 rearward allowing the door to be opened. By providing the forward projection 36b of the right resilient biasing arm 38 with a smooth surface, the door 50 may be opened and closed in a smooth, continuous movement. While the present invention has been described with regard to FIG. 9 in terms of the operation and interaction of the right tab 64 and the right resilient biasing arm 38, this description applies equally well to the interaction and operation of the left tab 56 and the left resilient biasing arm 36.
There has thus been shown a hinged door arrangement which is comprised of only two elements, i.e., a door and a support panel. The door and the support panel are directly coupled in a pivoting manner to allow the door to be easily positioned in a fully open or a fully closed position and to be biased closed when in an intermediate position. The door and the support panel combination are particularly adapted for use in a control panel of an electronic device and are each preferably comprised of a single piece of molded, high strength plastic. The door is easily installed on and removed from the support panel and the pivoting coupling therebetween does not involve the use of springs, magnets, latches, or a separate hinge mechanism.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art. | A door is pivotally mounted to a support panel by means of right and left outwardly directed mounting studs positioned on the support panel which are adapted for insertion within a respective aperture in a lateral portion of the door. The door is free to pivot about the mounting studs in a vertical direction and includes a pair of tabs extending from a lower portion of the door toward the panel. Each tab is aligned with a respective resilient biasing arm extending from the panel toward the door. Each door tab is engaged by a respective biasing arm when the door is moved toward the closed position so as to urge the door to the full closed position in which it is maintained by the biasing arms. When the door is opened by rotating it about an axis aligned with the mounting studs, the tabs are displaced from engagement with the biasing arms and the door is free to assume the full open position wherein it is maintained in a generally horizontal orientation by rotations stops. Each resilient biasing arm includes a forward cam surface for abutting an end portion of a respective tab in maintaining the door in a generally vertical closed position. | 4 |
CROSS REFERENCE TO RELATED APPLICATION
This Application is a Continuation-in-part of my copending application Ser. No. 09/099,264 filed Jun. 18, 1998.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to apparatus for performing a plurality of size reducing actions including impact fragmentation, cutting and shearing by means of an impact rotor mounted for rotation within a reduction chamber. More particularly, the present invention relates to the impact striker assembly carried by the lobes of a rotor which cooperate with a stationary anvil or wear surface and a grate to perform cutting and shearing action of the type described in U.S. Pat. No. 5,150,844 to McKie, especially the embodiment of FIG. 8 therein, the disclosure of which is included herein by reference.
2. Description of the Prior Art
Typical prior art heavy duty material reduction apparatus utilizing impact rotors of the type under consideration are disclosed in U.S. Pat. No. 4,151,959 to Deister and U.S. Pat. No. 5,150,844 to McKie. These patents are illustrative of the prior art utilizing either a radially attached, axially or helically extending cutter bar or striker plate. The McKie patent, for instance, illustrates a cutter bar extending axially on the surface of a rotating drum for direct impact cutting in cooperation with an anvil, hardened wear surface or grating. The cutter bar is also shown with multiple removable striker plates mounted thereon for contact with an anvil or other surface. The Deister patent illustrates still another type of impact rotor comprised of a series of rotary segments with offset, radially extending lobes for mounting removable striker plates. In both types of apparatus, the cutter bar or an attached striker plate includes a leading hardened cutting edge subject to severe wear and deterioration because of the high impact loads experienced during material processing. The cutter bar or striker plates may be symmetrical so as to include two cutting edges with the striker plate or cutter bar being capable of reversal or turning to utilize a second cutter edge. Whether the cutter bar or striker plate is unitary or segmented, it is necessary to completely remove the plate or bar assembly from the rotor in order to replace a cutting edge or to reverse the position of the cutter bar or striker plate. In heavy duty rotary hogs this operation is not only expensive and time consuming but requires access to the massive rotor element under hazardous working conditions.
Although other types of cutter bars striker plates and removable cutting edges have been proposed, either the entire striker plate or cutter must be removed for reworking or the complexity of the attachment means for removable cutting elements precludes their use in heavy duty crushers and rotary hogs. For instance, there is a need for replaceable cutting tools or bits which may be removed by easily accessible bolts without requiring lateral movement of the parts. The cutting tool or bit and striker plate must at the same time be configured for simplicity and maximum ruggedness in order to withstand the extremely high impact pressures without fracturing. The attaching means must be arranged so as not to interfere with the material processing and require no particular special skills to manipulate.
SUMMARY OF THE INVENTION
The present invention provides an impact striker assembly including a striker plate adapted for attachment directly to the radially extending rotor lobe of a heavy duty, size reducing apparatus commonly known as a rotary hog. The striker plate bits or cutting tools are attached as inserts to the striker plate and may be adapted for use with either a single cutter bar or segmented rotors most commonly used in the art. The inserts obviate the necessity of removal of striker plates or cutter bars for reworking the hard cutting edge surface. Either single or multiple replaceable striker bits may be used for any particular striker plate as a matter of choice or design. Each striker bit or tool insert is symmetrical about a central longitudinal plane passing through the bit so that it may be easily removed, rotated 180° and remounted on the striker plate without removing the striker plate itself. The striker plate configuration is adaptable for use with most designs of rotors having radial lobes for that purpose. Each striker bit is mounted directly to the top edge of the striker plate, projects forwardly and presents a cutting edge and face which is inclined forwardly from the front face of the striker plate to present an aggressive rake angle with the radial line through the axis of the rotor in the direction of rotation of the rotor. Each striker bit is formed with a central longitudinal recessed channel adapted for reception of retaining bolts and includes protrusions on the back side thereof which interfit with matching recesses in the top edge of the striker plate to enhance the positioning and retention of the bit on the face of the plate. With the top edge of the striker plate extending radially beyond the rotor lobe, easy access is provided for mounting and removing the bits from the striker plate thus alleviating any problem of access for removal and/or rotation of the bits. With this structure, one or more of the bits may be rotated or replaced in a fraction of the time it normally takes to remove the entire striker plate structure as is commonly done at present with existing structures. Since the striker bits are moved forwardly off of the face of the striker plate, requiring no vertical or sideways shifting, individual bits in a series may be removed if necessary with no problem of accessibility and without disturbing adjacent bits or striker plates.
In one embodiment of the invention, the striker plate is constructed with a wedge shaped body in its longitudinal direction, i.e. in the direction of the axis of the rotor, for the purpose of orienting the striker bit mounting face and hence the cutting edges and faces of the striker bits at an angle with respect to the rotor axis. The striker plates may thus be utilized on rotor lobes having front mounting faces extending in an axial direction relative to the rotor axis for the purpose of obtaining additional shearing action on the material to be reduced. Providing a cutting or shearing angle in the range 0°-20° on the cutting edges of the striker assemblies, in this case the cutting edges of the striker bits, causes the edges to bite into the material with a shearing action rather than merely a crushing action against the anvil. It would also be possible to utilize the wedge shaped striker plates to adjust or change an existing angle of the lobe mounting face. The striker plates may be angled in either direction i.e. the thickness of the wedge shaped body may be increasing or decreasing from right to left relative to the rotor axis, depending upon the design of the particular material reduction equipment. Since the cutting action occurs prior to the crushing of the material against the anvil, the "surge" effect experienced with some crushing machines may be alleviated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a rotor equipped with the striker assembly of the present invention;
FIG. 2 is a side elevational view of the standard prior art rotor with conventional striker plates;
FIG. 3 is a detail view of the dotted line circled portion in FIG. 2;
FIG. 4 is an exploded perspective view illustrating the method of attachment of the bits to the striker plate as well as the connection between the striker plate and the rotor lobe; and
FIG. 5 is a cross sectional view of the striker assembly;
FIG. 6 is a perspective view of a rotor section with angled striker plates of a second embodiment;
FIG. 7 is a top plan view of the second embodiment of the striker assembly having the striker plate angled in the opposite direction from that illustrated in FIG. 6; and
FIG. 8 is a top plan view of an angled striker assembly of the type shown in FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a typical rotor for a material size reduction processing apparatus such as a rotary hog. The rotor body 10 illustrated is constructed of solid cast metal but it will be understood that the present invention is equally applicable to any rotor configuration whether solid or drum type having a striker plate mounting surface. In most installations, such as used for reduction of wood, fiber and mixed material, the rotor 10 is carried on a motor driven shaft 11 for high speed rotation of the cutters within a closed chamber. The rotor 10 is a massive structure weighing several tons, depending upon the width and diameter of the rotor. The illustrated rotor is of the segmented type wherein successive lobed segments extend axially along the shaft 11. Each successive segment is circumferentially offset in the direction of rotation indicated by the arrow in FIG. 1, forming a stepped row of striker mounting faces in a helical pattern along the axis of the shaft 11. In practice it is customary to offset the lobes in the order of 15°-20° of circular rotation. This arrangement is illustrated as being typical and it will be understood that many variations of this configuration are available in the art. Although variable, depending on the particular rotor design, each lobe segment 12 may range in width from 1/2-13 inches with a typical rotor having a width in the neighborhood of approximately 12 inches in the axial direction, the illustrated rotor typically having a total nominal width of 48 inches.
As illustrated in FIG. 1, each rotor lobe 12 is provided with a striker assembly indicated generally at 13, which includes a striker plate 14, a striker bit 15 and threaded connectors or bolts 16 connecting the striker plate to the face of the rotor lobe 12. The closed reduction chamber will also include an anvil means 17 and a grate 18 shown schematically in FIG. 1. The configuration, positioning and functioning of the anvil and grate structures and their cooperation with the striker plate assembly is well known and understood by those familiar with the art.
FIG. 4 is an exploded elevational view illustrating structural details of the striker plate, striker bits and threaded connectors. Each striker plate 14 is designed to extend the width of an associated rotor lobe and may be constructed from solid steel with an upper body portion 19 and a lower body portion 20 of increased thickness. The lower body portion forms an offset ledge or recess having a bottom surface 21 and a front face 22 for receiving the removable bits presently to be described. For this purpose, the surface 21 is disposed at an obtuse angle relative to the face 22. The body of the striker plate also includes a lower front face 23 and a rear face 24 for cooperation with the rotor lobe. Each lobe 12 of the rotor is provided with a planar front mounting face 26 and a bottom surface 27 at right angles thereto designed to receive the striker plate with the rear face 24 of the striker plate in full face engagement with the front face 26 of the lobe as shown in FIG. 1. It will also be noted, as shown in FIG. 4, that the junction between the front face 22 and the bottom surface 21 of the recess in the striker plate is provided with a radius as shown at 28 to eliminate any weakness or fracture line in the body of the striker plate.
As aforementioned, each striker plate is provided with connectors for clamping the striker plate to the front face of the associated rotor lobe. In the illustrated embodiment, the connectors comprise two mounting bolts 16 which extend through the body of the striker plate, as shown in FIG. 1, the hex heads 29 of each of the bolts 16 being received by suitable matching recesses 31 in the face 23 of the striker plate. As also illustrated in FIG. 1, the bolts 16 extend through suitable bores in the lobes 12 and are provided with nuts 32 located in suitable recesses 33 on the top surface of lobes 12. With this arrangement, the striker plates 14 are solidly clamped against the face of the lobes with sufficient torque applied to the bolts to ensure a solid connection capable of withstanding the severe impact pressures encountered during the cutting action. Although only two connector bolts 16 have been illustrated, it will be understood that the invention is not so limited and the assembly could include any number of bolts, some installations requiring up to seven or more connectors.
Details of the striker bits 15 are shown most clearly in FIGS. 4 and 5 with each bit comprising a generally rectangular solid steel body with longitudinal cutting edges having appropriately hardened surfaces as will presently be described. The present illustrated embodiment utilizes two such striker bits assembled side-by-side on a single striker plate with the bits being identical in all respects and thus interchangeable. For this reason the description of only one such bit will suffice. Although the present preferred embodiment illustrates the use of two bits for each striker plate, it will be understood, of course, that a single bit may be used or, in the alternative, more than two bits may be mounted on one striker plate, depending upon the desired rotor design. The bit body includes top and bottom opposing planar surfaces 34 and 36 respectively which extend in converging planes in the direction of the striker plate as illustrated most clearly in FIG. 5. The bit body also includes a rear face 37 adapted to engage the front face 22 of the striker plate as shown in cross section in FIG. 5. The end faces 38 of the bit are also planar in order to allow the bits to be assembled in end-to-end relation with no substantial break on the striker plate. The bits are held in position in the recess of the striker plate by means of the hex head retention bolts 39 which pass through suitable bores in the bit. In the illustrated embodiment, the bolt heads are located in the recesses 41 in the bit face but it will be understood that the bolts may be used either with or without the recesses. The bolts 39 are received in suitable bores 42 in the upper body portion 19 of the striker plate and secured by hex head nuts 43 as illustrated. The top and bottom rear edges 44 and 46 of the bits will be configured to conform to the face of the striker plate.
As seen most clearly in FIG. 1, the upper body portion 19 of the striker plate extends above the rotor surface and the rear face 24 of the plate is provided with semi circular recesses 47. The recesses 47 open upwardly into the top surface of the back edge of the striker plate giving easy access for removal of the nuts 43 and to facilitate clean-out of the area around the nuts which may accumulate debris during operation of the rotor. The bores 42 in the striker plate include enlarged diameter surface recesses 48 in the face 22 for reception of mating circular protrusions 49 on the back face 37 of the bits. These protrusions and recesses insure proper indexing of the bits and aid in preventing vertical or lateral movement of the bits relative to the striker plate once in place.
The front face of each bit comprises a central longitudinal surface 51 with opposite forwardly inclined parallel cutting edge surfaces 52 and 53 on either side thereof. The surfaces 52 and 53 are inclined outwardly from the center area 51 with the intersection of the surfaces 52 and 53 with the top and bottom surfaces 34 and 36 respectively of the bit body forming cutting edges 54 and 56 respectively. As seen in FIGS. 1 and 5 the surface 52 is inclined forwardly from the planes of the front and rear surfaces of the bit at an angle Θ which may be in the neighborhood of approximately 0°-10°. In this respect, it will also be noted that the front face 22 of the upper portion of the striker plate body may be inclined forwardly with the respect to the rear surface 24. With the striker plate installed on the rotor lobe as illustrated in FIG. 1, the forward inclination of the cutting edge surface of the bit will produce a rake angle φ of from 0°-25° with a radial line through the center of the rotor in the direction of rotation. The amount of rake angle will, of course, depend upon the orientation of the striker plate as it engages the face of the lobe 12. The rake angle described has been found to be extremely advantageous and produces an aggressive cutting action in cooperation with an anvil or grate.
In practice, each striker plate 14 is initially provided with one or more bits 15 having hardened cutting edges which function in conjunction with the anvil and the grate to perform the impact fragmentation, cutting and shearing within the reduction chamber. When the original cutting edges become worn and need replacing, it is only necessary to remove the bolts 39, rotate the bits 180° and reclamp them on the striker plate and the rotor is ready for operation. When both surfaces of the bit are worn, the bit may be replaced by another and the original cutting edges of the worn bit reworked. This operation is contrasted to the present practice indicated in FIGS. 2 and 3 wherein the rotor lobes are provided with striker plates 57 suitably clamped to the face of the associated lobe in the manner described. Each striker plate has a forward cutting surface and edge 58 having a hard surface material such as a welded tungsten carbide beads or equivalent hard surface coating laid on the cutting surface as shown in FIG. 3. When the edge 58 and hard surface become worn, it is necessary to remove the entire striker plate 57, replace the hard surface coating along the edge and then replace the striker ready for reuse. Because of the size of striker plates, the removal of the connecting long bolts, the necessity of reworking the cutting edge of the striker and then replacing the whole assembly, many man hours are spent periodically reworking the striker plate edges. In addition, this operation must be carried on with the rotor in place within the reduction chamber presenting work space limitations and the danger of working with the massive elements in a restricted space. The removal and replacement of old style strikers requires special tooling and a minimum of two men to perform the operation. One man may easily remove the smaller connecting bolts of the striker bits of the present invention and replace them or rotate them in a fraction of the time that it takes to replace the entire striker plate assembly.
FIG. 6 illustrates a second embodiment of the striker assembly constructed in a fashion to provide a cutting or shearing angle for the striker plate and, in the present embodiment, the cutting edges and cutting faces of the striker bits relative to the rotational axis of the rotor. The rotor section 10 in FIG. 6 is illustrative of a well known rotor segment design and may be understood to be the same construction, in all respects, as described for the rotor 10 in FIG. 1, including its mounting on the power driven shaft 11 having an axis of rotation 11a. As described relative to the FIG. 1 embodiment, each lobe 12 is provided with a planar front mounting face 26 and a bottom surface 27 at right angles thereto designed to receive a striker assembly. It is noted that the mounting face 26 in the embodiment shown is located in a plane either parallel to or passing through the center line of the rotor. With this design, if a cutting edge is located parallel to the mounting face 26, the reducing action is primarily one of crushing between the striker assembly or other cutting edge or surface and the anvil. Very little if any shearing or cutting is accomplished at any other location in the path of the rotor. This results naturally in a "surging" of the material being crushed although the device is subject a continuous feeding process.
According to the present embodiment, the novel striker plate 57 includes an offset ledge or recess having a bottom surface 58 and a front face 59 for receiving the removable striker bits 15 which may be identical to those described relative to the FIGS. 1-5 embodiment and may be mounted to the striker plate 57 in the same manner as previously described. The striker plate 57 includes a bottom surface for contacting the surface 27 of the offset in the lobe 12 and a rear planar face 61 for contacting the front face 26 of the lobe 12. The mounting connection between the striker plate 57 and the rotor lobe 12 may be in all respects identical to that previously described for FIGS. 1-5 embodiment.
As seen most clearly in FIGS. 7 and 8, when viewed in plan, the striker plate 57 has a tapered or wedge shaped body with the general plane of the rear face 61 being disposed at an angle to the striker bit mounting face 59. With the striker plate mounted in position on the lobe 12, and with the mounting face 26 of the lobe being in a plane parallel to the axis of rotation 11a, the striker bits 15 and the front mounting face 59 are disposed at a cutting angle relative to the axis 11a. Thus when the rotor is traveling in the direction of the arrow in FIG. 7, the cutting edges and faces of the bits 15 create a shear force on the material being reduced as the rotor moves, allowing the cutting edge to bite into the material even prior to contact with the anvil. The striker assembly performs like a blade using shear force to reduce the material before crushing it against the anvil. In practice, the angle of the cutting edges of the striker bits relative to the axis of rotation may range from 0°-20°. It will also be readily apparent that the cutting edge may be angled forwardly in the direction of rotation in either direction from the axis of rotation. The mounting in FIGS. 7 and 8 illustrates an angle directed forwardly in the right hand direction relative to the direction of rotation of the rotor; while the mounting in FIG. 6 depicts a left hand directed angle. The direction of the angle of the cutting edge will depend upon the design desired for any given rotor.
By cutting rather than merely crushing the material to be reduced, the present invention is able to handle larger volumes of material without the surging effect experienced with other designs. The surging effect results when the material to be reduced is crushed between the striker and the anvil since the material must be sufficiently reduced before more material can be accepted. Since the rotary hog is normally fed by constant feeder means, the surging effect results with the axially aligned strikers performing more in the nature of paddles than blades. With the present striker assembly, the resulting shear force reduces the material before it is crushed against the anvil enabling more effective reduction and a more continuous material flow.
Although the present invention has been disclosed as used with rotor lobe mounting faces in a plane generally parallel to the rotor axis, striker plates of the present configuration may be used to increase or decrease existing angled striker faces. It will also be understood that the combination of the aggressive rake angle of the cutting edge as previously described along with the shear angle of the striker bit cutting edges improves the effective reduction of the material.
It is to be understood that the foregoing description and accompanying drawings have been given by way of illustration and example. It is also to be understood that changes in form of the several parts, substitution of equivalent elements and arrangement of parts which will be readily apparent to one skilled in the art are contemplated as within the scope of the present invention, which is limited only by the claims which follow. | A striker assembly for attachment to the rotor lobe of a rotary hog for impact fragmentation, cutting and shearing action. The striker assembly includes a striker plate having a body portion attachable to the rotor lobe by means of screwthreaded connectors with the top portion of the striker plate extending radially beyond the rotor periphery. The striker plate has an offset ledge for receiving one or more striker bits which are clamped thereto by appropriate bolts and which include protrusions on the rear face thereof in engagement with mating recesses in the striker plate face. Each striker bit is symmetrical around a central longitudinal plane with opposed cutting edges running the length of the bit. The bit is removable and may be rotated 180° allowing alternate use of the cutting edges. The bit includes forward faces adjacent the cutting edges which are disposed at an angle to the front and rear faces of the bit so as to provide an aggressive cutting edge. When mounted on the striker plate, and depending upon the orientation of the striker plate, a rake angle of 0°-25° is formed. In one embodiment, the striker plate is wedge shaped for disposing the cutting edges of the striker bits at an angle relative to the rotational axis of the rotor to exert a shearing action on the material before impact with an anvil. | 1 |
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