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BACKGROUND
This invention relates to a rod-shaped fiber composite material having a wall composed of a tube-shaped circular braid formed from right-handed and left-handed helical strands of fiber material and a matrix material embedding the helical strands of the circular braid. The present invention further relates to a process for producing a rod-shaped fiber composite material, in particular a present invention rod-shaped fiber composite material, and also to apparatus for continuous production of a rod-shaped fiber composite material.
Fiber composite materials are generally known. They comprise a matrix material in which the fibers are embedded. The fibers confer on the fiber composite material a stiffness and strength which is high relative to the mass of the material, in particular in fiber direction. The matrix material serves in particular to protect the fibers and to induct the arising forces into the fibers.
Fiber composite materials having a profile- or rod-shaped configuration are also known in particular. Particular fiber composite materials comprise fibers which are at least in part configured as a circular braid which is surrounded by the matrix material. Profiles composed of such a fiber composite material can be utilized to produce very stable structural components. To additionally reinforce such circular braids, it is known to include in the wall of the circular braid further fibers, if appropriate in the form of strands, whose orientation extends essentially in the longitudinal direction of the fiber composite material.
The fiber composite materials mentioned are regarded as disadvantageous in having in relation to their mass a torsional strength and stiffness which is not sufficient or not sufficiently defined for high loads, and also insufficient resistance to buckling.
The present invention has for its object to provide a rod-shaped fiber composite material which compared with existing fiber composite materials can be used at high loads, in particular torsional loads and flexing loads. The present invention further has for its object to provide a process for such a fiber composite material and also apparatus for producing such a fiber composite material.
We have found that this object is achieved by a rod-shaped fiber composite material having a wall composed of a tube-shaped circular braid formed from right-handed and left-handed helical strands of fiber material and a matrix material embedding the helical strands of the circular braid, wall chambers extending in the longitudinal direction of the rod-shaped fiber composite material being formed in the region of the wall of the tube-shaped circular braid between the right-handed and left-handed helical strands and being bounded by a defined phase boundary of the matrix material.
The phase boundaries separate the wall chambers from the matrix and the fibers. They permit a multiplicity of advantageous executions of the fiber composite material, irrespective of whether the phase boundaries are solid-gaseous, solid-liquid or solid-solid. These advantages reside for example in transportation means for media and signals or else in the improvement of mechanical properties of the fiber composite material. A multiplicity of possibilities will now be elucidated in detail.
Useful fiber materials include the fiber materials customarily used for fiber composite materials, examples being carbon fibers, glass fibers, polymeric fibers such as aramid fibers or else natural fibers. Metallic fiber materials can further find use in the circular braid. Useful matrix materials include for example plastics, in particular synthetic resins such as polyurethane, polyester, polyether-ketones, or else glass materials or concrete. Possible matrix materials further include thermoplastics such as PBT, polypropylene and polyamide and also elastomers such as neoprene and rubber. Natural matrix systems can also be advantageous. Means for incorporation include direct injection of the matrix material, in situ polymerization or else the use of hybrid yarns comprising fiber material and a matrix material which is heated in the course of production.
The tube-shaped circular braid has a cylindrical shape which, depending on the required performance profile, can have a wide variety of cross sections or can be brought into a wide variety of cross sections. Circular braids normally have a circular cross section. For applications where the rod-shaped fiber composite material is configured to accommodate one or more lines for power or fluids, circular cross sections are regarded as advantageous. However, elliptical, polygonal or more complex cross sections are also conceivable for example and advantageous in specific instances, for example in relation to the production of structural components, for example for chassis building. The circular braid comprises helical strands of two different orientations, which are interbraided in a conventional manner to form a stable ensemble. The helical strands are in part left-handed and in part right-handed. The braided structure wall has crossing zones which extend in the longitudinal direction of the circular braid and in which the left and right-handed helical strands cross. Between these crossing zones, extending in the longitudinal direction of the circular braid, the present invention provides wall chambers which are likewise oriented in the longitudinal direction and which each reside between the left-handed and right-handed helical strands. Viewed in the circumferential direction, wall chambers having either the right-handed helical strands on the outside and left-handed helical strands on the inside or else the left-handed helical strands on the outside and the right-handed helical strands on the inside lie side by side and alternate. Owing to these wall chambers, the right and left-handed helical strands are further spaced apart perpendicularly to the wall of the circular braid, compared with a normal circular braid. The matrix material into which the circular braid has been embedded bounds the wall chambers on the outside and on the inside and has a defined phase boundary in relation to the wall chambers. The wall chambers themselves preferably have a round or elliptical cross section. In relation to the rod-shaped fiber composite material of the present invention it may be preferable to provide a core tube in the interior of the circular braid in a known manner. The core tube may also be filled, for example for stabilizing purposes. Thus, depending on the application scenario, it is for example an option to fill the interior of the circular braid completely with optionally foamed matrix material and optionally further fiber material, so that only the wall chambers are free of fiber material and matrix material of the circular braid.
The fiber composite material of the present invention has high torsional strength and stiffness and is also very buckling resistant and highly pressure resistant. The properties of the fiber composite material may if appropriate be additionally application-enhanced by fillings or inlays into the wall chambers. This can reach such a point that the stability of the fiber composite material is essentially due to the inlays or fillings and the circular braid essentially only serves to stabilize these inlays against buckling and/or change in position. In addition, the wall chambers can also serve as transportation paths for liquids and gases or else accommodate lines for transporting electrical energy or electrical or optical signals.
In one further development of the fiber composite material, fiber longitudinal strands likewise embedded in the matrix material within and/or outside the circular braid extend essentially in the longitudinal direction of the rod-shaped fiber composite material.
These fiber longitudinal strands are particularly suitable for keeping the volume of the matrix material small and for absorbing tensile forces acting in the longitudinal direction. The fiber longitudinal strands can consist of the same fiber material as the circular braid or a different fiber material than the circular braid. It is particularly preferable when the fiber longitudinal strands are inserted into interstitial cutouts which extend in the longitudinal direction and which result, inside and outside the circular braid, in the region of the crossing points between left and right-handed helical strands.
In one further development of the fiber composite material, at least one and preferably all of the wall chambers are filled.
Such a filling can have a positive influence on the properties of the rod-shaped fiber composite material. As well as filling all wall chambers, it may also be preferable to fill just some of the wall chambers to improve the material properties and to leave others unfilled, for example for gas transportation. The filling in the wall chambers is preferably introduced into the wall chamber during the manufacturing operation. It may be preferable, depending on the application scenario, to provide in the wall chambers a filling which is inlaid therein as a prefabricated inlay of defined phase boundary and which, depending on its form of introduction, terminates flush with the matrix material or sits only loosely in the wall chamber. Alternatively, fillings which are introduced into the wall chambers in liquid form in particular and cure or consolidate therein are also convenient.
In one further development of the fiber composite material, a line, in particular an electrical line or an optical wave guide, is inlaid into at least one of the wall chambers.
Using wall chambers to transmit electrical energy or electrical or optical signals is regarded as advantageous particularly whenever a core tube in the fiber composite material is intended to transport fluids, for example, and therefore no lines can be accommodated there. The lines can either be configured such that they completely fill the wall chamber and terminate flush with the matrix material, or that they are merely inlaid and remain mobile in the longitudinal direction of the fiber composite material. The inlaid line may have an isolating/insulating layer, but depending on the matrix material used it is also possible to use directly inserted guides/conductors without isolating/insulating layer. It may further be preferable to inlay a plurality of lines together in a previously cured wall chamber.
In one further execution of the present invention, at least one wall chamber is configured as a line for transportation of fluids or a line for transportation of fluids is inlaid into at least one of the wall chambers.
For this purpose, the wall chamber may have been provided with a separate line which is preferably introduced during the manufacturing operation of the fiber composite material, or else the wall chamber is itself directly used as a duct whose wall is bounded by the matrix material of the fiber composite material. When a separate line is used, both a line which completely fills out the wall chamber and a line which is movable at least to some extent in the longitudinal direction may be advantageous.
In one further development of the fiber composite material, at least one of the wall chambers, preferably all wall chambers, contain an inlaid stabilizing inlay which fills out the wall chamber and has a defined external area, in particular a stabilizing bar.
Such a stabilizing inlay preferably fills out each wall chamber completely and has a common phase boundary with the adjoining matrix material. Bars composed of fibers embedded in a binder, in particular carbon fibers embedded in a binder, are regarded as particularly advantageous. The stabilizing inlays make it possible to adapt the properties of the fiber composite material in a specific manner to specific requirements, in which case particularly tensile and compressive loads can be efficiently absorbed. The stabilizing inlays may also be configured such that they absorb a large proportion of the loads which arise, in which case their being braided into the circular braid ensures their being held safely in their position without any danger of their giving away or of changing their position. The stabilizing inlays, in particular the stabilizing bars, can be prefabricated to have defined predetermined properties.
In one further development of the fiber composite material, the phase boundaries separating the wall chambers and their respective contents from the matrix are smooth and the wall chambers have a cross section uniform in the longitudinal direction.
Wall chambers of this design are comparatively simple to produce by introducing into the circular braid, in the region of the wall chambers, in the course of a continuous manufacturing operation, a mold core which, depending on the application scenario, remains in or is pulled out or otherwise removed, in particular dissolved out, from the fiber composite material after consolidation of the matrix.
In a further development of the fiber composite material, within and/or outside the tube-shaped circular braid there is provided a further tube-shaped circular braid embedded in the matrix material, the further tube-shaped circular braid preferably likewise having wall chambers arranged in the region of the wall between right-handed and left-handed strands and oriented in the longitudinal direction of the tube-shaped circular braid and separated from the matrix material by a phase boundary.
Such a fiber composite material, comprising a plurality of circular braids, preferably each with wall chambers, has even further enhanced buckling resistance and torsional strength. The increased number of wall chambers also permits particularly flexible adaptation to specific requirements, for example by the wall chambers of the outer circular braid being used for inlaying stabilizing inlays and the wall chambers of the inner circular braid being used for inlaying ducts, in particular electrical lines or optical wave guides, particularly well protected by the outer circular braid.
The present invention further provides a process for producing a rod-shaped fiber composite material having a tube-shaped circular braid formed from left and right-handed helical strands and a matrix embedding the helical strands, preferably for producing a fiber composite material according to the present invention. In this process the tube-shaped circular braid is braided around rod-shaped wall chamber formers disposed in the region of the circular braid wall as mold cores to form a defined phase boundary, the wall chamber formers being braided into the region between crossing left and right-handed helical strands and subsequently the matrix material for forming the matrix embedding the helical strands of the circular braid and for forming the defined phase boundary is introduced into the circular braid, the wall chamber formers remaining in the wall chambers at least until the matrix material is at least partly consolidated or cured. The process is useful for continuous operation.
The process commences with a conventional continuous braiding operation in which the helical strands used are braided around the wall chamber formers, so that these cause the inner right-handed and outer left-handed helical strands on the one hand and the inner left-handed and outer right-handed helical strands on the other to be spaced apart. Introducing the matrix material, which embeds and consolidates the helical strands, causes the wall chambers to be brought into a permanent shape and the defined phase boundaries formed, and they also persist when the wall chamber formers move out of the wall chambers after at least partial consolidation or curing of the matrix material in the course of the continuous advance of the fiber composite material produced. Alternatively, however, the wall chamber formers can also be configured as lost mold cores, which remain in the wall chambers.
In a further embodiment of the production process, the wall chamber formers are intended to remain in the rod-shaped fiber composite material and are fed continuously to the braiding operation, the wall chamber formers being configured as stabilizing bars in particular.
The feeding is preferably realized in the region of a circular braiding apparatus having flyer wheels for transporting spools, the wall chamber formers being fed through a cutout in the center of these flyer wheels. The wall chamber formers may be configured not only to positively influence the material properties of the fiber composite material but also to be able to serve directly to transport fluids or electrical power or electrical and optical signals. The use of stabilizing bars makes it possible to produce a fiber composite material wherein the circular braid and the matrix material primarily serve to keep the stabilizing bars in position and to prevent any giving way and also positional changes on the part of the latter, while the stabilizing bars bear the main loads.
In one further development of the production process, the wall chamber formers for forming free wall chambers are configured stationarily and continuously move out of the wall chambers formed in the region of the at least partly cured or consolidated matrix.
The wall chamber formers in this case thus serve only to shape the wall chambers and to form the defined phase boundaries without remaining in the wall chambers. Such wall chamber formers are likewise preferably disposed in the region of the flyer wheels of the circular braiding machine, and extend in the transportation direction of the fiber composite material into a region downstream of a feed region for the matrix material in which the matrix material is at least consolidated to such an extent that the wall chambers are stable after the wall chamber formers have moved out. This process is technically not very demanding, and can be carried out with only minimal modifications to commercially available braiding machines. For this purpose, these braiding machines are equipped for example in the region of their flyer wheels with preferably rodlike wall chamber formers which extend at least as far as into an apparatus for introducing the matrix into the wall.
In a further development of the production process, during the continuous moving out of the wall chamber formers a wall chamber filling is introduced into the wall chamber surrounded by at least partly cured matrix material. The feeding of the wall chamber filling is preferably effected through the stationary wall chamber formers which are tubular for this purpose. An apparatus for introducing the wall chamber filling into the wall chamber formers is preferably part of the braiding apparatus. The feeding takes place as a function of the speed of advance of the fiber composite material produced.
In one further development of the production process, the filling is configured as a prefabricated solid continuous inlay.
This inlay may for example be stored, and continuously fed, on rollers in the region of the braiding apparatus. Depending on the intended application, these inlays can perform transportation purposes, for example for gases and liquids or else for electricity or electric signals. Such continuous inlays, when compared with inlays which are not introduced through stationary wall chamber formers but are themselves configured as lost wall chamber formers, are mobile, which may be advantageous, in the longitudinal direction of the fiber composite material in the inlaid state even after the matrix material has undergone consolidation. This avoids the risk for example of the inlay being injured when the final fiber composite material is pressed into curves having narrow radii in the course of its use.
In one further development of the production process, the filling is introduced as a flowable medium, for example as a foam material, which consolidates, in particular cures, after introduction in the wall chamber.
For this purpose, the flowable material is preferably fed under pressure through the wall chamber formers to the wall chamber which it completely fills out and in which it subsequently turns solid. Such a filling can improve the properties of the fiber composite material in various ways.
In one further development of the production process, the circular braid is shaped before consolidation or curing of the matrix material, in particular before the embedding into the matrix material.
This makes it possible to endow the fiber composite material produced by the process with a shape, in particular a cross-sectional shape, which is very difficult or impossible to produce in the course of the original production of the circular braid. The shaping may be caused by forces acting on the circular braid from the outside or from the inside. The shaping can also be effected by the fiber composite material being influenced in its longitudinal direction, for example through slightly screw-shaped secondary chamber formers, which result in screw-shaped wall chambers.
In a particularly advantageous further development, the shaping takes place with regard to the cross section, in particular through a force emanating from the wall chamber formers and/or from bounding external or internal surfaces of a mold.
The wall chamber formers may for this purpose have an arrangement which changes the direction of advance of the fiber composite material. It may be preferable for example for the wall chamber formers to be disposed on a circle circumference in the region in which the circular braid is produced and in the further course to assume for example a rectangular arrangement or an arrangement in the form of the cross section of a C-, T-, L- or LZ-beam, so that the circular braid is, in the course of its continuous advance, pressed into this shape before or while the matrix material is being introduced or consolidates.
In one further development of the production process, at least two circular braids guided inside each or one another and the matrix material are joined together to form a rod-shaped fiber composite material, the wall chamber formers for forming the defined phase boundary being braided into at least one of the circular braids.
Such a process can be carried out in one or more stages. A one-stage process produces concurrently two circular braids of which at least one, preferably both, are provided with wall chambers by wall chamber formers. The two circular braids are preferably firmly bonded to each other using a conjoint matrix material.
In another further development of the production process, the process is carried out in two or more stages, a rod-shaped fiber composite material produced in the first stage, comprising a first circular braid, being surrounded in a second stage with a second circular braid and being connected to the latter by the matrix material.
It is preferable here to use identical matrix materials and fiber materials. In the case of for example different loads to be expected to react on the outer surface of the fiber composite material and on the wall of a core tube, it may also be preferable to use a second matrix material and/or a second fiber material for the second stage and hence the outer layer of the fiber composite material produced, which differ from the respective matrix and fiber materials used in the first stage.
The present invention also provides an apparatus for continuous production of a rod-shaped fiber composite material comprising a braiding apparatus configured for braiding a circular braid, an applying apparatus for applying a matrix material to helical strands of the circular braid and a curing apparatus for curing the matrix material, wherein the braiding apparatus comprises rod-shaped wall chamber formers of defined cylindrical external surface which are disposed such that they are braided into the wall of the circular braid and extend through the applying apparatus into a region of the curing apparatus in which the matrix material has been at least partly cured or consolidated.
The braiding apparatus comprises a conventional braiding apparatus for producing circular braids, although wall chamber formers are attached to the braiding apparatus in the region of spools of the braiding apparatus, preferably where the braiding apparatus has flyer wheels. These wall chamber formers extend essentially in the direction of transportation of the fiber composite material, and serve to being braided around with the helical strands of the circular braid. The wall chamber formers extend through the applying apparatus in which the circular braid is embedded into the matrix material, defining wall chambers which are excluded from having matrix material introduced to them and so form the defined phase boundary. The identity of the matrix can be adapted to various requirements in many respects, for example by the choice of the matrix material or by foaming to reduce the density of the material. The wall chamber formers end in or behind the curing apparatus in which the matrix material is cured or consolidated. When, in the course of the continuous advance of the fiber composite material produced, the wall chamber formers are thus continuously moved out of the wall chambers, stable wall chambers remain behind owing to the curing or consolidation. The wall chambers endow the fiber composite material produced using such an apparatus with a high degree of stability coupled with low mass, and also permit the performance of specific functions, for example in the region of fluid or energy transportation. A particular embodiment is advantageous when hybrid yarns are used. Hybrid yarns consist of reinforcing fibers on the one hand and matrix filaments, for example thermoplastic filaments, on the other. In the case of these hybrid yarns, the fiber material and the matrix material are conjointly braided together by means of the braiding apparatus. The office of the applying apparatus in this case is not to feed the matrix material, but only to heat it sufficiently for homogeneous distribution on the fibers. The curing apparatus is configured as a cooling apparatus in this case.
In one further development of the production apparatus, the applying apparatus for applying the matrix material and the curing apparatus are configured as a unitary apparatus.
The curing apparatus preferably merely comprises a curing and shaping sector in the course of which the matrix material is guided on the external surface and in the course of which the matrix material is consolidated. Depending on the embodiment, a mold core may additionally be provided in the interior to define a clear core tube during consolidation.
In one further development, the production process comprises an appliance for reshaping the circular braid after its production.
Such a refinement permits a particularly flexible adaptation of the circular braid and of the fiber composite material to performance requirements. The apparatus comprises for this purpose a sub-apparatus which permits a targeted force acting on the circular braid. This can be a mold core within the circular braid, whose cross-sectional area varies in the advance direction by for example having in the region of the braiding apparatus a round cross section whose shape develops in the advance direction into a rectangular shape for example. Of advantage may also be, in lieu or in addition, a shaping apparatus which is disposed outside the circular braid and which presses the circular braid into a desired shape in the course of the continuous advance of the circular braid. The combination of a shaping mold core within the circular braid with a shaping apparatus outside the circular braid permits particularly flexible shapings of the circular braid with cross sections comprising concave and convex regions of walling.
In one further development of the production apparatus, the wall chamber formers are shaped such that a pattern formed by the wall chamber formers changes downstream of a region in which the circular braid is produced compared with the original pattern such that the circular braid produced is continuously changed with regard to its shape, in particular with regard to its cross section.
This further development makes it possible to achieve a continuous shaping of the circular braid without additional shaping apparatuses disposed inside or outside the circular braid. As the circular braid is further transported in the direction of advance, the arrangement of the wall chamber formers, which likewise changes in the direction of advance, leads to a shifting of the wall chambers of the circular braid and consequently to a continuous change in the shape of the circular braid, for example with regard to its cross section proceeding from a circularly round braid to a circular braid in the form of a T-beam. It may also be advantageous to achieve a screw-shaped form for the wall chambers via wall chamber formers disposed and helically configured in the same direction.
In one further development of the production apparatus, the wall chamber formers are tubularly hollow.
Such a development makes it possible to feed the wall chambers with a filling during the production of the fiber composite material.
In one further development of the production apparatus, the wall chamber formers are configured to feed a solid inlay into the wall chambers formed by the wall chamber formers.
The solid inlay is preferably stocked on spindles or in the form of rod material in the region of the braiding apparatus, and continuously fed through the wall chamber formers into the wall chambers. Advantageous inlays can serve not only the stability of the fiber composite material but also comprise inlays performing specific functions in the region of fluid or electricity transportation.
In one further development of the production apparatus, the wall chamber formers are configured to feed a pressurized flowable medium into the wall chambers produced by the wall chamber formers which consolidates or cures after introduction into the wall chambers.
This makes it possible to positively influence the material properties of the fiber composite material in a specific manner by feeding a filling into the wall chamber.
These and further features will be apparent from the description and the drawings as well as the claims, and the individual features may each be actualized on their own or as a plurality in the form of subcombinations in any one embodiment of the invention and in other fields and may constitute advantageous embodiments which are protectable in their own right and for which protection is claimed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
Illustrative embodiments of the invention are schematically depicted in the drawings and will now be more particularly described. In the drawings:
FIGS. 1 to 5 show various embodiments of inventive fiber composite materials,
FIGS. 6 to 8 show various embodiments of inventive apparatuses for producing a rod-shaped fiber composite material,
FIG. 9 a shows sections of wall chamber formers of an inventive apparatus for producing a rod-shaped fiber composite material of trapeze-shaped cross section,
FIGS. 9 b to 9 e show a sectional view of the wall chamber formers depicted in FIG. 9 a , at various positions in the direction of advance, and
FIG. 9 f shows an inventive fiber composite material whose trapeze-shaped cross section is due to the wall chamber formers depicted in FIGS. 9 a to 9 e.
DETAILED DESCRIPTION
In the various embodiments of the fiber composite material and the various embodiments of the production apparatus, the second and third digits of the reference symbols for mutually comparable components are in agreement in each case.
The profiles of the inventive fiber composite material which are depicted in the illustrative embodiments of FIGS. 1 to 5 can have very different designs with regard to their cross-sectional dimensions. The profiles can have a diameter of a few millimeters and a cross-sectional area of a few square millimeters. To produce structural components, for airplanes, for example, however, distinctly larger diameters up to in the range of several decimeters are also conceivable. Particularly preferred embodiments have diameters in the region of a few centimeters, for example a diameter of 2 centimeters coupled with a wall thickness of 5 mm in the region on the wall chambers and a clear wall chamber cross-sectional area of about 10 square millimeters, which in the case of circular cross sections for the wall chambers corresponds to a clear wall chamber diameter of about 3.5 mm.
The circular braids depicted in these illustrative embodiments each have a pitch angle for the helical strands based on longitudinal and circumferential direction of about 10° to 20°. Depending on the planned use for the fiber composite material and depending on the number of helical strands and the cross-sectional dimensions of the overall profile and also of the wall chambers, however, smaller and larger pitch angles can also be advantageous. An advantageous pitch is lower for higher bending strength requirements and higher, up to between 50° and 60°, for higher torsional strength requirements.
FIGS. 1 and 2 show very simple embodiments of the inventive profilelike fiber composite material. The fiber component of these fiber composite materials 100 , 200 is formed by circular braids 102 , 202 which consist of helically extending fiber strands 104 a , 104 b , 204 a , 204 b . Of these fiber strands 104 a , 104 b , 204 a , 204 b , altogether twelve of each are provided in the circular braids 100 , 200 , and in turn of these in each case six fiber strands 104 a , 204 a are braided into the circular braids 102 , 202 in the clockwise sense in the advance direction 106 , 206 in the perspective of FIGS. 1 and 2 and in each case six fiber strands 104 a , 204 b are braided into the circular braids 102 , 202 helically counterclockwise in the advance direction 106 , 206 in the perspective of FIGS. 1 and 2 . The fiber strands 104 a , 104 b , 204 a , 204 b are braided such that in each case altogether twelve wall chambers 108 , 208 are left in the wall of the circular braid 102 , 202 . These wall chambers 108 , 208 are each disposed between crossing zones 110 , 210 in the wall in the circumferential direction, the left-handed fiber strands 104 a , 204 a and the right-handed fiber strands 104 b , 204 b being superposed in these crossing zones 110 , 210 in a plan view in the direction of the advance direction 106 , 206 . The wall chambers of the two circular braids 102 , 202 differ from each other in their cross-sectional shape: The wall chambers 108 in circular braid 102 have circular cross-sectional areas, while the cross-sectional areas of the wall chambers 208 in circular braid 202 have an elliptical shape. The circular braids 102 , 202 are each surrounded by a matrix material 112 , 212 which forms an outer wall 114 , 214 for the fiber composite materials 100 , 200 . Within the fiber composite materials 100 , 200 , the wall chambers 108 , 208 and also in each case a core tube 118 , 218 are free in each case not only of fiber strands but also of the matrix 112 , 212 formed by the matrix material. The matrix 112 , 212 is cured in the state depicted in FIGS. 1 and 2 , so that the cross section which is depicted for the wall chambers 108 , 208 is the final cross section.
The depicted fiber composite materials 100 , 200 have high stability and stand up well to high torsional loads and flexing loads in particular. The free wall chambers 108 , 208 , which lead to a radial spacing apart of the respectively inner and outer wall regions, prevent buckling of the fiber composite materials 100 , 200 . Depending on the intended use, the depicted wall chambers 108 , 208 can remain free or be provided with a filling, for example with lines or a stabilizing fill. When the wall chambers 108 , 208 remain free, they can be used for example to transport fluids, making it possible inter alia to cool or heat the medium to be transported in the core tube.
The embodiment of FIG. 3 differs from the embodiments of FIGS. 1 and 2 in two essential aspects. The fiber composite material 300 comprises as fiber component not only the circular braid 302 formed of right and left-handed fiber strands 304 a , 304 b , but also longitudinal fiber strands 316 a , 316 b which are oriented in the advance direction 306 and which have been embedded into the matrix material 312 in part as 316 a within the circular braid 302 and in part as portion 316 b outside the circular braid 302 . The longitudinal fiber strands are disposed in particular in interstitial spaces between the left and right-handed fiber strands 304 a , 304 b in the region of the crossing zones 310 . The fiber composite material 300 has enhanced stability to tensile loads as a result. The second essential difference to the embodiments of FIGS. 1 and 2 resides in the filling of all wall chambers 308 . These are filled out by a consolidated foam 322 , which endows the fiber composite material 300 with additional stability. The rod-shaped fiber composite material 300 depicted in FIG. 3 therefore permits any desired transportation of media to take place only through the core tube 318 . In embodiments not depicted, however, only a portion of the wall chambers can be filled out with a consolidated foam, so that the other wall chambers can be used for other purposes.
The fiber composite material depicted in FIG. 4 corresponds in principle to the fiber composite material of FIG. 3 except for this filling of cured foam 322 . The free wall chambers 408 , however, are inlaid with optical wave guides 424 , which can transport data signals. Owing to the structure of the fiber composite material 400 with its high buckling resistance, good protection of the optical wave guides 424 is ensured even when the fiber composite material is subject to a high stress. The arrangement in various wall chambers 408 , moreover, has the advantage that even in the event of an injury to the fiber composite material 400 it is generally the case that not all optical wave guides 424 are injured, since they are each protected separately by the circular braid 402 .
The fifth embodiment of an inventive fiber composite material, depicted in FIG. 5 , corresponds to the embodiment of FIG. 2 with regard to the shape of the circular braid 502 and of the matrix material 512 . However, the wall chambers 508 are similarly filled to the embodiments of FIGS. 3 and 4 , the filling consisting in the form of stiff bars 522 of carbon fibers. The carbon fibers are bound into a binder. The bars fill the wall chambers 508 completely out, or do themselves form filled wall chambers 508 as it were. The phase boundary of the matrix 512 is thus immediately adjacent to the phase boundary of the carbon fiber bars 522 . The purpose of the carbon fiber bars 522 is the defined absorption of tensile and compressive forces. In this embodiment, the circular braid 502 itself only secondarily serves to absorb such forces. Its primary office is to hold the carbon fiber bars 522 and protect them from giving way and breaking out. In addition, the circular braid 502 also ensures that the carbon fiber bars 522 are fixed with regard to their angle position around the longitudinal axis, so that this orientation does not change, which would otherwise lead to an irregular buckling resistance depending on the angle of a radial load. In the production of this embodiment, the fiber bars 522 serve as endless wall chamber formers and enduring mold cores.
In further embodiments, not depicted, of inventive fiber composite materials, the number of wall chambers can also differ from the depicted twelve wall chambers and be in particular higher.
FIG. 6 shows a first embodiment of an inventive apparatus for producing a fiber composite material 600 , for example for producing a fiber composite material of the kind of the fiber composite material 200 depicted in FIG. 2 . The apparatus comprises two main components 640 , 670 , of which the first main component is a braiding apparatus 640 . The second apparatus is a combined applying and curing apparatus 670 , in which a circular braid 602 , produced by the braiding apparatus 640 , is provided with a matrix material 612 , and in which the matrix material 612 subsequently cures.
To produce the circular braid 602 , the braiding apparatus 640 has, in a conventional manner, altogether twelve spools 642 , which each have a fiber spindle 644 and an unwinding arm 646 , with which the fiber material 604 for the circular braid 602 is taken off the fiber spindles 644 and fed to the circular braid 602 . In a manner not evident from FIG. 6 but known in principle, the spools are guided essentially circularly on a guiding disk 648 , six spools 642 at a time moving essentially in the clockwise direction and six spools 642 moving essentially counterclockwise. The spools each alternate in their movement between an inner and an outer track, so that the counter rotatory movement of the spools 642 does not lead to a collision of the spools 642 . Between the tracks which are not depicted and in which the spools 642 are guided and which each constitute alternatingly via the circle circumference the inner or outer track as may be the case, wall chamber formers 650 are secured to the guiding plate 648 , bend slightly toward each other and extend essentially in the advance direction, depicted with arrow 606 , of the fiber composite material 600 . These wall chamber formers 650 are orbited by the spools 642 in such a way that a circular braid 602 in which the fiber strands 604 a , 604 b are braided around the wall chamber formers 650 is formed in the manner depicted. This circular braid 602 , unfolded and guided on the wall chamber formers 650 , is further transported into the applying and curing apparatus 670 , where it arrives in an applying chamber 676 . A feed line 672 , which ends in the applying chamber 676 , presses a curable matrix material in the direction of the arrow 674 into the applying chamber 676 , where it surrounds the circular braid 602 and embeds the individual fiber strands 604 a , 604 b of the circular braid 602 . Only a core tube 618 remains free of the matrix 612 , since a cylindrical mold core 652 extends from the guiding disk 648 of the braiding apparatus 640 as far as into the applying and curing apparatus 670 , and the wall chambers 608 also remain free of the matrix 612 , since the wall chamber formers 650 likewise extend into the applying and curing apparatus 670 . In the course of the further transportation of the circular braid 602 and of the surrounding matrix 612 , the matrix material 612 cures and the resulting stable fiber composite material 600 is conveyed out of the region of the wall chamber formers 650 and also of the mold core 652 . Owing to the cured matrix material 612 , the wall chambers 608 remain behind in a stable state.
FIG. 7 shows a second embodiment of an inventive apparatus for producing a fiber composite material. The fiber composite material 700 produced using the apparatus of FIG. 7 , similarly to the fiber composite material depicted in FIG. 3 , has an additional stabilization in the form of a foam filling which, like the matrix material 712 , also cures in the course of the production operation. This foam filling 722 is forced under pressure in the form of a liquid medium 726 through the wall chamber formers 750 into the wall chambers 708 . The wall chamber formers 750 , as illustratively depicted in section for one wall chamber former 750 , is tubularly hollow for this purpose. The conveying apparatus for the medium 726 is not depicted in FIG. 7 . The conveying apparatus is situated in the region of the braiding apparatus 740 and conveys the medium 726 through the guiding disk 748 into the wall chamber formers 750 .
FIG. 8 depicts a third embodiment of an inventive apparatus for producing a fiber composite material. This apparatus corresponds essentially to the apparatus depicted in FIG. 7 in that a filling is introduced into the wall chambers 808 which are shaped by the wall chamber formers 850 , with the feed again being through the wall chamber formers 850 . However, the inlay fed in this case comprises optical wave guides 824 which are only loosely inlaid. The conveying appliance is not depicted, as was also the case for the apparatus of FIG. 7 . However, the conveying appliance is likewise situated in the region of the braiding apparatus 840 , although the optical wave guide 824 , unlike medium 726 for the foam filling 722 , is hauled off a drum before being introduced into the wall chambers 808 .
In further embodiments of the inventive apparatus for producing a fiber composite material which are not depicted, the number of wall chamber formers and/or of spools differs from the depicted embodiments. More particularly, a higher number of spools is advantageous to obtain a particularly strong circular braid. The number of spools need not necessarily be equal to the number of wall chamber formers. There are advantageous apparatuses for example where 24 spools are used to braid around a total of twelve wall chamber formers.
When, in lieu of the tube-shaped wall chamber formers 850 and the optical wave guides 824 solid endless rods of bound fibers are carried along and embedded in the circular braid into the matrix material, this leads to the embodiment of FIG. 5 .
FIG. 9 a shows a section of an arrangement of wall chamber formers 950 which are configured to reshape a circular braid 902 into a trapeze shape. Such an arrangement of wall chamber formers can find utility in apparatuses as depicted in FIGS. 6 to 8 .
The wall chamber formers 950 are shaped such that their arrangement constantly changes in the advance direction 906 . In a first region in the advance direction 906 , the wall chamber formers form an arrangement B, which is depicted in FIG. 9 b in cross section. In this arrangement B, the wall chamber formers 950 are disposed on a conjoint circular circumference. This is also the region in which the circular braid 902 is braided.
In a subsequent second region, depicted in FIG. 9 c , the arrangement is already slightly changed in that the upper wall chamber formers 950 tend toward the center and the outer wall chamber formers 950 are veering toward the outside at left and at right. The resulting arrangement C reveals a slightly asymmetric shape in the vertical.
In a third region, depicted in FIG. 9 d , the wall chamber formers 950 are each still further deflected in their particular direction compared with the original arrangement B. This arrangement D clearly reveals a trapeze shape.
In the last region, depicted in FIG. 9 e , the wall chamber formers 950 are in their trapeze-shaped target arrangement E.
The circular braid produced in the first region continuously changes its shape, as depicted in FIGS. 9 b to 9 e , in the course of continued transportation in direction 906 , and ultimately assumes the trapeze shape in accordance with the orientation of the wall chamber formers 950 . In this trapeze shape, the circular braid then arrives in a combined applying and curing apparatus (not depicted) which corresponds to that of the illustrative embodiments in FIGS. 6 to 8 . After the matrix material has been introduced in the combined applying apparatus to embed the circular braid 902 and the matrix has cured, the fiber composite material having a trapeze-shaped cross section is ready produced.
The ready produced fiber composite material is depicted in FIG. 9 f.
Nondepicted fiber composite materials produced similarly to the fiber composite material depicted in FIG. 9 f are made with different cross-sectional shapes such as for example those of C- or LZ-beams. It may be advantageous in this connection to achieve the shaping not just via the wall chamber formers but additionally via a shaping appliance which changes in the advance direction and is disposed outside the circular braid.
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The invention relates to a rod-shaped fiber composite material ( 400 ) composed of a matrix ( 412 ) and a circular braid ( 402 ) embedded into the matrix. To increase the stability of the fiber composite material ( 400 ) and also to perform ducting functions for electricity and fluids, the wall of the circular braid is provided with wall chambers ( 408 ) which are separated by a phase boundary from the matrix ( 412 ) of the fiber composite material ( 400 ). These wall chambers ( 408 ) lead to inner and outer sections of the wall of the circular braid ( 402 ) being spaced apart, which is useful for the stability with regard to flexing and torsional loading in particular. Rod-shaped fiber composite materials ( 400 ) according to the invention can be used for creating stable structural components as well as for producing efficiently protected ducts. The invention further relates to an apparatus and a process which are useful for producing fiber composite material according to the invention.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to hair spray resin compositions, and more particularly, to water-based compositions which contain a multiple polymer system.
2. Description of the Prior Art
Present hair spray compositions, both pump spray and aerosol spray formulations, are described in detail in U.S. Pat. Nos. 3,145,147; 4,223,009; and 4,521,402. These compositions generally perform effectively in providing most of the properties considered desirable for hair preparation, including fine spray patterns, prolonged curl retention under humid conditions, good holding power, ease of removability, and resistance to build-up. However, these and other pump formulations available in the art contain a considerable amount of alcohol which is a volatile organic compound (VOC). Aerosol hair spray formulations also require hydrocarbons or other propellants which add to the VOC content of the composition. Recent state legislation, moreover, has required that hair spray compositions have a lower VOC level than is presently found in commercial hairspray compositions. More particularly, it is now necessary that such compositions contain VOC materials at a weight level of no more than 80% of the composition.
Accordingly, it is an object of the present invention to provide new water-based hair spray compositions which meet VOC standards while retaining the effective properties of presently available compositions for hair preparation and treatment.
Another object of the invention is to provide water-based hair spray compositions capable of providing a fine finishing mist at a high resin solids level and which is substantially moisture resistant, which also forms a stiff resin film on the hair of the user, and provides a good hold and curl retention, with superior shine, and feel, and low drying times, which approach the properties of alcohol-based systems.
These and other objects and features of the invention will be made apparent from the following more particular description thereof.
SUMMARY OF THE INVENTION
A water-based hair spray composition is provided herein which is capable of delivering a fine finishing mist at a high resin solids level. The composition provides a stiff resin film having excellent hair holding power, with superior shine, and feel, and low drying times, which properties approach those of alcohol-based systems. The composition of the invention attains its unique attributes by including a predetermined blend of at least two hair spray polymers, one being a water soluble polymer, and the other being a water dispersible polyester or polyesteramide.
DETAILED DESCRIPTION OF THE INVENTION
The composition of the invention comprises
(a) one or more water soluble polymers and
(b) a water dispersible polyester or polyesteramide derived from:
(1) at least one dicarboxylic acid or ester,
(2) at least one diol, and
(3) a difunctional monomer containing an SO 3 M group attached to an aromatic nucleus, wherein M is hydrogen, or metal ion or ammonium ion or the cationic radical of an organic amine;
polyesteramide improves the set time (tac-free time) and shine of the water soluble polymers thereby expanding the use of commercially available water soluble polymers into an aqueous-based hair spray composition which has a drying character, time and feel which approaches to an alcohol-based system.
Polymer blends particularly useful herein for incorporation into the hair grooming composition comprise:
(a) about 99 to about 1 wt. % of a water soluble polymer, and
(b) about 1 to about 99 wt. % of a water-dispersible sulfonate group-containing polyester or polyesteramide.
A method for using these hair grooming compositions comprises:
(i) contacting the following:
A. one or more water soluble polymers, and
B. a water-dispersible sulfonate group-containing polyester or polyesteramide,
C. water, and, optionally,
D. a neutralizing agent to obtain 65 to 100% neutralization based on the acid monomer in the water soluble polymer, including metal hydroxides and aliphatic, cyclic, or aromatic amines;
(ii) applying the composition to hair, and evaporating the solvent, thereby holding the hair in place.
The final hair grooming composition preferably comprises:
(I) about 2 to about 28 weight % of a polymer blend comprising:
(a) about 99 to about 1 weight % of a water soluble polymer, and
(b) about 1 to about 99 weight % of a water-dispersible sulfonate group-containing polyester or polyesteramide,
(II) about 98 to about 40 weight % of water,
(III) 0 to about 30 weight % of an alcohol, and
(IV) 0 to about 5 weight % of a neutralizing base sufficient to neutralize the acid groups of the polymer blend.
Water-dispersible polyesters and polyesteramides useful herein are described in detail in U.S. Pat. Nos. 3,734,874; 3,546,008; 4,335,220; and 3,779,993; and are available from Eastman Chemicals as Polymers AQ 38 and 55.
Preferably, the polyester or polyesteramide has an inherent viscosity of from about 0.28 to about 0.38, an acid moiety of from about 75 to about 84 mole % isophthalic acid and conversely from about 25 to about 16 mole % 5-sodiosulfoisophthalic acid, and a glycol moiety of from abut 45 to about 60 mole % diethylene glycol and conversely from about 55 to about 40 mole % 1,4-cyclohexanedimethanol or ethylene glycol or mixtures thereof.
Most preferably, the polyester or polyesteramide comprises an acid moiety comprising from about 80 to about 83 mole % isophthalic acid and conversely from about 20 to about 17 mole % 5-sodiosulfoisophthalic acid, and said glycol moiety comprises from about 52 to about 56 mole % diethylene glycol and conversely from about 48 to about 44 mole % 1,4-cyclohexanedimethanol.
The water soluble polymers useful herein are preferably prepared from monomers of one or more of the following structures: ##STR1## wherein R 1 is a C 1 -C 5 aliphatic group, preferably a C 1 -C 3 alkyl group, or is of the structure ##STR2## wherein R 6 and R 7 are, independently, a C 1 -C 5 alkyl group,
R 2 is a C 1 -C 10 aliphatic group, preferably a C 1 -C 3 alkyl group,
R 3 is a C 1 -C 16 aliphatic group, preferably a C 8 alkyl group,
R 4 is H or a C 1 -C 8 aliphatic group, preferably H or a C 8 group,
R 5 is a C 1 -C 10 aliphatic group, preferably a C 9 alkyl group.
Accordingly, suitable water soluble polymers include polyvinyl pyrrolidone (PVP), polyvinyl caprolactam (PVC), polyvinyl acetate (VA), polyacrylates and methacrylates, and copolymers and terpolymers of such monomers, such as VP/VA, VA/crotonic acid/vinyl neodecanoate, VA/crotonic acid, or octylacrylamide/acrylates/butyl aminoethyl methacrylate, VA, mono-n-butyl maleate and isobornyl acrylate; and VP/VC/dimethylaminoethyl methacrylate.
1. Gaffix®VC-713 (GAF Chemicals Corporation) which is a terpolymer derived from the polymerization of vinyl caprolactam, vinylpyrrolidone and an ammonium derivative monomer having from 6-12 carbon atoms selected from the group consisting of dialkyl dialkenyl ammonium halide and a dialkylamino alkyl acrylate or methacrylate (see U.S. Pat. No. 4,521,404). The commercial product is available as a ethanolic solution having a 37% solids level.
2. Gantrez®SP-215 (GAF Chemicals Corporation) is the ethyl half-ester of a linear copolymer of methyl vinyl ether and maleic anhydride.
3. Gantrez®ES-225 (GAF Chemicals Corporation) is the ethyl half-ester of a linear copolymer of methyl vinyl ether and maleic anhydride having a molecular weight of 978,000.
4. Gantrez®ES-425 (GAF Chemicals Corporation) is the butyl half-ester of a linear copolymer of methyl vinyl ether and maleic anhydride having a molecular weight of 1,000,000.
5. Resin 1212 (GAF Chemicals Corporation) is a terpolymer derived from the polymerization of vinyl acetate, mono-n-butyl maleate and isobornyl acrylate (see U.S. Pat. No. 4,689,373), having a molecular weight of about 250,000.
In a preferred embodiment, the polymer blend is prepared as follows: the sulfonate group-containing polymer is prepared, generally by melt polymerization, and an aqueous dispersion containing from about 10% to 30% total solids is prepared from the polyester or polyesteramide directly. Then the water soluble polymer or polymers are added to the aqueous dispersion of the polyester or polyesteramide to produce an aqueous dispersion. The aqueous dispersion so produced can be prepared with a total solids content of from about 1 to about 30. Preferably, the pH is, or is adjusted to be, within the range of about 4-8 in order to minimize hydrolysis of the polyester.
A preferred polymer blend system comprises:
(a) water soluble polymer; GAFFIX®VC-713 (ISP) having the formula: ##STR3## (b) water dispersible polymer Eastman AQ Polymer having the formula: ##STR4## A=An aromatic dicarboxylic acid moiety B=An aliphatic or cycloaliphatic glycol residue, and
--OH=hydroxy end groups
A typical formulation of the composition of the invention is as follows:
______________________________________EXAMPLE AMOUNTINGREDIENT (% BY WT) SUPPLIER______________________________________Purified Water 93.06Gaffix ® VC-713 1.00 ISP(37% in ethanol)Polymer AQ 55D 5.00 Eastman KodakPVP/VA W 735 ISPCrovol A-70 0.10 CrodaPanthenol 0.10 Tri-KSuttocide A 0.60 SuttonSurfadone ® LP-300 0.07 ISPFragrance 0.07Citric Acid QS 100.00______________________________________
The above formulation was a one-phase system. Upon testing as a pump hair spray, it was observed that the spray patterns developed were fine, broad and dry, with a soft hold, and excellent shine, and low drying times; the properties were comparable to those of commercial alcohol-based systems.
While the invention has been described with particular reference to certain embodiments thereof, it will be understood that changes and modifications may be made which are within the skill of the art. Accordingly, it is intended to be bound only by the following claims, in which:
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A water-based hair spray composition is provided herein which is capable of delivering a fine finishing mist to provide a stiff resin film having excellent hair holding power, with superior shine, and feel, and within a relatively low drying time, approaching that of alcohol-based systems. The composition of the invention attains its unique attributes by including a predetermined blend of at least two hair spray resins, one being a water soluble resin, and the other resin being a water dispersible polyester or polyesteramide.
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[0001] This invention was made with Government support under contract DE-FC26-05NT42422 awarded by the Department of Energy. The United States Government has certain rights in this invention.
FIELD OF THE INVENTION
[0002] The present invention relates to internal combustion engines and more specifically to prime mover systems incorporating internal combustion engines and power extraction devices.
BACKGROUND OF THE INVENTION
[0003] For over a hundred years, piston engines have been utilized to convert the energy in hydrocarbon based fuel to useful power outputs. Typically, these engines have incorporated variable volume combustion chamber or chambers using a cycle having an intake portion, a compression portion, an expansion portion and an exhaust portion. The variable volume combustion chamber is most typically defined by a reciprocating piston in a cylinder bore and connected by appropriate mechanical devices to a crankshaft or other rotary output component. The engines may be two cycle or four cycle according to the need.
[0004] The consideration of efficiency has always been important but with advances in regulatory limits during the last twenty years, reducing emissions, including nitrous oxides, has become exceedingly important. The usual steps for combustion management to minimize emissions typically decrease efficiency of the engine. In the case of the compression ignition or diesel engine cycle, the need to reduce oxides of nitrogen requires significant alteration to the operating conditions which tends to decrease the otherwise outstanding efficiency of such an engine type.
[0005] A number of attempts have been made to increase efficiency by fully utilizing the energy available in such engines through power extraction devices in the exhaust of the engine. Such power extraction devices may be a turbo supercharger (turbocharger) which receives the exhaust from the engine and drives a compressor connected to the engine intake by appropriate manifolds. The heat of pressurization by the compressor may be supplied to an intercooler or aftercooler to reduce the temperature of the gases flowing into the engine and thus increase the density of the mixture. Another energy extraction device is found in a power turbine which may be used to supply additional power to the engine output via an appropriate mechanical connection or may be used to drive a turbo generator supplying electrical energy for accessory and other loads.
[0006] While some systems have been proposed to provide a separate exhaust for different power extraction devices, such systems do not provide a system having a maximum efficiency.
[0007] Accordingly, what is needed in the art is a prime mover system incorporating an internal combustion engine and power extraction devices which more efficiently utilize the energy available from the internal combustion engine.
SUMMARY OF THE INVENTION
[0008] In one form, the invention is a prime mover system having a reciprocating internal combustion engine. The engine has at least one intake valve for admitting combustion air into a variable volume combustion chamber with a volume varying between a minimum and maximum and at least a first and second valve for discharging products of combustion. A first exhaust flow path is provided from the first exhaust valve and a power turbine is fluidly connected to the first exhaust flow path and drives a load. A second exhaust flow path from the second exhaust valve is fluidly connected to a turbocharger having a turbine fluidly connected to the second exhaust flow path and a compressor driven by the turbine for pressurizing air for delivery to the at least one intake valve. A valve actuation system is provided for opening the first exhaust valve to discharge exhaust to the power turbine before the chamber has reached a maximum volume after a combustion event and to open the second exhaust valve to discharge exhaust to the turbocharger turbine after the chamber has reached maximum volume.
[0009] In another form, the invention is a method of operating an internal combustion engine having at least one intake valve for admitting combustion air into a variable volume combustion chamber and at least a first and second exhaust valve for discharging products of combustion. The method includes opening the first exhaust valve to exhaust a portion of the products of combustion approximately before said variable volume combustion chamber reaches its maximum volume after a combustion event to drive a power turbine connected to a load. The second exhaust valve is opened to discharge exhaust to a turbocharger, after the combustion chamber has reached its maximum volume after said combustion event.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows a schematic drawing of a prime mover system embodying the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] FIG. 1 shows a prime mover system 10 having an internal combustion engine 12 with multiple cylinders in which pistons (not shown) reciprocate to provide variable volume combustion chambers 14 . Although the engine shows three cylinders, it should be apparent to those skilled in the art that a great variety in the number of cylinders may be employed, according to the size and to the duty cycle required of the engine 12 . The combustion chamber 14 has at least one intake valve 16 and preferably an additional intake valve 18 for admitting combustion air from an intake manifold 20 passed via passages 22 and 24 . The air thus introduced into combustion chamber 14 goes through a cycle including an intake portion, compression portion, expansion portion and exhaust portion. The air that has been pressurized is combined with fuel from a fuel system 26 and ignited to combust and drive the expansion portion of the cycle to generate power.
[0012] The combustion process may be a spark ignition in which a combustible hydrocarbon fuel is mixed with intake air from intake manifold 20 and ignited by an ignition device, usually in the form of a spark plug. The mixing of fuel and air may take place in the intake manifold passages 22 and 24 and even in the combustion chamber 14 . Another form of combustion type is compression ignition in which the pressurized air from intake manifold 20 is pressurized to such a degree that when fuel is injected directly into the combustion chamber 14 from fuel system 26 the mixture ignites and produces the expansion portion of the cycle. Many varieties of fuel systems are utilized for this purpose and the current type most in use is a system in which the fuel quantity and timing is controlled electronically and the pressure generated either at each individual cylinder, in the case of a unit injector, or in a high pressure common rail.
[0013] The combustion chambers 14 also have exhaust valve 26 and 28 for each cylinder to discharge products of combustion. The exhaust valve 28 fluidly connects to a first exhaust flow path 30 leading to an exhaust manifold 32 and then to a power turbine 34 via conduit 33 . A second exhaust flow path 36 leads from valve 26 to a second exhaust manifold 38 connecting via conduit 40 to a turbine 42 of a turbocharger 44 . As will be described in detail below, the cross-sectional flow area of the first exhaust passages 30 are smaller than the cross-sectional flow area of the second exhaust passages 36 . Furthermore the total volume of the exhaust passages 30 , exhaust manifold 32 , and conduit 33 is smaller than the volume of the corresponding second exhaust passages 36 , exhaust manifold 38 and passage 40 .
[0014] The valves 14 , 18 , 26 and 28 are actuated by appropriate systems. The intake valves 16 and 18 are actuated by a system schematically shown at 46 having mechanical interconnections represented by dashed lines 48 . Like fuel systems, the valve actuation systems can be any one of a variety of systems including hydro-mechanical or piezoelectric. The valves 28 are actuated by a device 50 mechanically interconnected by an appropriate system indicated by dashed line 52 . The valves 26 are actuated by a system 54 through mechanical interconnection represented by 56 .
[0015] The output from power turbine 34 may be used to drive a load 58 which may be a turbo generator or a device that mechanically interconnects with the prime output of internal combustion engine 12 . The gases discharged from power turbine 34 pass through conduit 60 where they pass through an aftertreatment device 62 and finally to an exhaust 64 . The aftertreatment device may be used to remove particulates and reduce oxides of nitrogen through appropriate catalysts and other processes. The output from turbocharger turbine 42 passes through conduit 66 where it joins conduit 60 and passes through the aftertreatment device 62 .
[0016] Intake air for engine 12 is taken from ambient via conduit 68 which feeds a compressor 70 driven by turbine 42 for pressurizing air for delivery through conduit 72 to an aftercooler 74 and conduit 76 to the intake manifold 40 .
[0017] The prime mover system may also include exhaust gas recirculation (EGR) which has a conduit 78 connected to conduit 60 and leading to an optional EGR cooler 80 and appropriate metering device 82 to introduce a portion of the products of combustion via conduit 84 to the inlet conduit 68 .
[0018] Optionally, a combustor 86 may be interposed in line in conduit 33 upstream of power turbine 34 . Combustor 86 receives fuel via a line 88 extending to fuel system 26 . Combustor 86 incorporates an appropriate ignition device and controls to produce additional energy to power turbine 34 as needed.
[0019] In the operation of engine 12 , the combustion chambers 14 have a variable volume which ranges between a minimum and maximum volume. When the combustion chambers 14 incorporate reciprocating pistons it is common to refer to the minimum volume condition as top dead center (TDC) and the maximum volume condition as bottom dead center (BDC). The intake portion of the cycle causes valves 16 and 18 to be open to admit air for combustion into the combustion cylinder. The air thus admitted is compressed to a point where the combustion chamber 14 is at a minimum volume state. At this point combustion occurs and the energy of combustion drives the combustion chamber volume towards a maximum volume condition. When the pistons are defining the variable volume portion of the chamber the combustion event drives the piston towards a maximum volume state and the movement is converted into a rotary output. In the past, the thermal energy of the process has been focused on to the exclusion of the blow down energy of the gases within the chamber. In accordance with the invention, the valves 28 are opened before the combustion chamber reaches maximum volume so that a portion of the energy otherwise supplied to the piston at a lower energy rate is made available to drive the power turbine 34 .
[0020] The valve actuation system 50 provides a faster opening of the valve 28 than valve 26 and the smaller cross sectional flow area and volume between the combustion chamber and the power turbine ensures that the maximum pressure is available at the power turbine 34 . The faster opening rate of valve 28 reduces throttling loses across that valve. The valve actuation system 50 opens the valve 28 at approximately 90 degrees before BDC, or maximum chamber volume. This causes the pressure ratio across turbine 34 to be greater than otherwise is experienced in such a system. The power turbine 34 has a pressure ratio of from between approximately 4-6:1 so that a maximum amount of energy is extracted via the power turbine 34 . The actuation system 50 then closes the valves 28 at approximately BDC or maximum combustion chamber volume and then the actuation system 54 opens valves 26 to provide the exhaust of the products of combustion which are passed to the turbocharger turbine 42 via a larger flow path and larger capacity system. This splitting of the exhaust flows ensures that the energy in the form of pressure is available in an optimum manner to the power turbine 34 and the remaining energy available is passed through a larger flow area to the turbocharger turbine to provide optimum utilization of the energy available from the combustion process.
[0021] Such a system allows much higher power output than is seen from current turbo compounded engine. In addition, the arrangement of the power extraction devices permits an enhanced EGR process in which a minimum of EGR is required to reduce emissions.
[0022] Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.
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An internal combustion engine having a reciprocating multi cylinder internal combustion engine with multiple valves. At least a pair of exhaust valves are provided and each supply a separate power extraction device. The first exhaust valves connect to a power turbine used to provide additional power to the engine either mechanically or electrically. The flow path from these exhaust valves is smaller in area and volume than a second flow path which is used to deliver products of combustion to a turbocharger turbine. The timing of the exhaust valve events is controlled to produce a higher grade of energy to the power turbine and enhance the ability to extract power from the combustion process.
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RELATED APPLICATION/CLAIM OF PRIORITY
[0001] This application is related to and claims priority from provisional application Ser. No. 60/565,427, filed Apr. 26, 2004, and entitled Wireless Base Phone, which provisional application is incorporated by reference herein.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] The present invention relates to a modified cellular/wireless phone concept. A wireless base phone is designed to be a replacement for the traditional home or business phone of a type that is tied into a wired telecommunications network. The base phone of the present invention will receive and transmit wireless radio frequency signals from a wireless provider, such as Qwest, ALLTEL, AT&T, or other similar providers. The base phone can then be set up to transmit and receive to other satellite (auxiliary) cordless, and corded phones associated/linked with it through full duplex radio frequency or through the building's own wired network. This will allow consumers to eliminate the use and cost of the traditional telephone tied into the wired telecommunications network. The base phone can also (due to the new phone number portability legislation, which requires phone carriers to allow for the transition of telephone numbers from standard wired telecommunications network to wireless phones, which take the homeowners' or business's original phone number) enable a consumer to transfer a prior telephone number to the base phone. The base phone can also be a part of a wireless provider's family plan as one of the family plan phones; thereby, saving more money by eliminating the traditional wired phone when a customer has both wireless and traditional wired telecommunication plans.
[0003] Many people have a phone system for a house or business tied into the traditional wired telecommunications system. Some also purchase wireless phones from wireless providers thereby, incurring additional costs. To save money some of these individuals are disconnecting from the wired network and just using the wireless network. This has the disadvantage of leaving the home or business without the traditional base phone that always stays at the home or business and that everyone knows its phone number. Some individuals' even purchase an additional personal cell phone to leave at home but these are small, portable, and easily misplaced. In applicant's experience, people like having a larger phone or phones that stay in one place so they can always know where at least one phone is. Additional satellite (auxiliary) phones can be linked to the base phone, through cordless or wired connection, and placed around the house or building.
[0004] Many wireless providers sell family plans where the consumer purchases the first wireless personal phone for a base price and then additional wireless personal phones for a lower cost per phone. These additional phones can be distributed to family members. Sometimes an additional wireless phone is purchased and left at the home or business to serve as a replacement for the traditional wired phone that is associated with that location. This additional cellular phone can be lost or misplaced easily.
[0005] The present invention accomplishes the following
[0006] 1. A consumer can purchase the first wireless base phone that is similar to a traditional wired phone except for not being connected to the wired telecommunications network or otherwise known as the Public Switched Telephone Network (PSTN).
[0007] 2. Since it is similar in size to the traditional phone the wireless base phone won't be as easily misplaced or lost.
[0008] 3. The base phone receives and transmits full duplex radio frequency (or if so designed spread spectrum) signals to and from the wireless provider network such as AT&T, Qwest, Nextel, ALLTEL, to name a few.
[0009] 4. If the base phone was purchased in a wireless provider family plan, then additional personal wireless phones can be purchased and distributed to other individuals.
[0010] 5. The base phone is set up to transmit and receive full duplex (if so designed, spread spectrum capability) radio frequency (different frequency from those listed above) signals to and from nearby corded or cordless satellite (auxiliary) phones that are associated with it. GSM/CTS (Global System for Mobile Communications/Cordless Phone Telephony), DCS 1800 (Digital Cordless Standard), DECT (Digital European Cordless Phone Technology), or other newer or similar cordless technologies can be used for this aspect of the Wireless Base Phone to satellite (auxiliary) phone operation. This is similar to present wired systems in use except for the base phone not being tied into the wired telecommunications system (PSTN). The base phone is in circuit communication with the satellite (auxiliary) phones, e.g. by wired connections or by antenna-to-antenna connections.
[0011] 6. The new phone number portability legislation will allow consumers to transfer their prior telephone number to the new base phone. This will relieve the consumer from the need of having to inform customers, friends, clients, and family of a phone number change.
[0012] 7. The present invention allows the consumer to connect to a wireless telecommunications network, thereby allowing the consumer to not have to pay for access to a wired telecommunications network as well as access to a wireless telecommunications network.
[0013] Definitions: In this application, reference to a “base phone” means the telecommunication device (handset and/or phone base) that sets up a connection with the wireless provider. It receives transmissions from and sends transmissions to the wireless provider. The base phone also transmits the transmissions from the wireless provider to the satellite (auxiliary) phones and receives transmissions from the satellite (auxiliary) phones and transmits them to the wireless provider. Reference to a “Satellite or “auxiliary” phone means the telecommunication device (auxiliary handset and/or phone base) that receives and/or transmits and receives transmissions from/to the base phone.
[0014] Further features of the present invention will become apparent from the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic illustration of the components of a wireless base phone, according to the present invention;
[0016] FIG. 2 is a schematic illustration, depicting how the wireless base phone of this present invention transmits and receives to and from the wireless service provider and satellite (auxiliary) phones.
[0017] FIG. 3 is a block diagram schematically illustrating the frequencies as they pass through the Wireless Base-Phone from the wireless service provider to the satellite (auxiliary) phones and from the satellite (auxiliary) phones through the Wireless Base-phone to the wireless service provider.
[0018] FIG. 4 is a block diagram depicting how the Wireless Base-Phone can be used in conjunction with Internet digital Voice Over Internet Protocol (VoIP) technology.
DETAILED DESCRIPTION
[0019] FIG. 1 shows a base phone 100 that preferably comprises a telephone base 10 and a handset 11 supported on the phone base 10 . The handset 11 can be cordless or the telephone base 10 can be equipped with a cord 19 that links the handset 11 with the telephone base 10 . The handset 11 has a conventional audio speaker ear-piece 12 , a typical keypad 13 for dialing telephone numbers (or can have a rotary dial mechanism, which is not shown) or text type messaging, and a conventional microphone 14 that receives audio input. The handset 11 also has an antenna 16 , if it is a cordless phone. The phone base 10 has a set of molded indentations (not shown) or a single indentation to rest the handset 11 in. If the handset 11 is a cordless phone, the handset 11 is battery powered and is recharged by the battery charging system (not shown) built into the phone base 10 . The phone base 10 has a conventional electrical power cord 17 and a conventional power cord/wall outlet plug 15 . The base phone has an antenna 18 to transmit and receive full duplex radio frequencies (if so designed, spread spectrum capability) to the wireless service provider and to the satellite (auxiliary) phones 200 . This means the base phone 100 will be capable of receiving and transmitting in four frequencies. One outbound frequency to the wireless service provider paired with one inbound frequency from the wireless service provider. Another frequency will be used to send to the satellite (auxiliary) phones 200 and another frequency will be used to receive transmissions from the satellite (auxiliary) phones 200 .
[0020] The wireless base phone 100 is configured to look and feel like current phones that currently are in use and tied into the wired telecommunications network (PSTN). The handset 11 is larger than a personal cell phone 38 (shown in FIG. 2 ) and therefore easier to hold and cradle in a person's hand. The large phone base 10 makes it easy to set the handset 11 in a central location and find it easily whereas a personal cell phone 38 can be easily lost. The large Wireless Base-Phone 100 can be equipped to send radio frequency transmissions to satellite (auxiliary) phones 200 that can be set in convenient locations around a building, home, or business thereby negating having to have an internal telephone wired system in the building or home. This will help to reduce the cost of building homes, or structures or having to run wires throughout the structure if more phones are needed.
[0021] A telecommunications tower 21 with conventional antennae 22 transmits and receives wireless service provider telecommunication signals to and from the wireless base phone 100 and other personal wireless phones 38 (see FIG. 2 ).
[0022] The base phone 100 can also have other phones linked to it similar to current models on the market that a consumer can purchase with multiple linked phones. For the purposes of this patent application these linked phones are called satellite (auxiliary) phones 200 . Different configurations can be used and are described, but not limited to those below:
Each of the satellite (auxiliary) phones 200 comprises a satellite (auxiliary) phone handset 26 that can also have an optional cord 19 that links the handset 26 to a base 24 . The antenna 25 can be mounted to the handset 26 or to the base 24 . The receiver/transmitter (not shown) can be built into the base 24 or the handset 26 . A satellite (auxiliary) phone 200 can be cordless. In this case the antenna 25 is mounted to the handset 26 , which also contains the receiver transmitter (not shown). The base 24 acts as a recharging unit for the handset 26 . In cases where satellite (auxiliary) phone 200 has to be set long distances from the wireless base phone 100 , the base 24 can have a larger transmitter/receiver (not shown) built into it. This satellite (auxiliary) phone 200 can have a cord 19 or be cordless. Following is a description of how this corded and cordless system is set up. 1. In the case where the satellite (auxiliary) phone 200 is equipped with a cord 19 attaching base 24 to the handset 26 . The antenna 25 can be attached to the base 24 or to the handset 26 . 2. In the case where the satellite (auxiliary) phone 200 is cordless, the base 24 will have an antenna (not shown) and the handset 26 will also have an antenna 25 . The base 24 will be equipped to transmit in two sets of full duplex (if so designed, spread spectrum capability) radio frequencies. One frequency will be used to transmit to the wireless base phone 100 and the second frequency will be used to receive from the wireless base phone 100 . A third frequency will be used to transmit to the handset 26 and the fourth frequency will be used to receive from the handset 26 .
[0028] FIG. 2 is a schematic view showing how the communication device interacts with the various components. A wireless service provider transmitter receiver antenna 22 transmits and receives telecommunication signals. A structure 32 is typically where a wireless base phone 100 and wireless satellite phones 200 will be situated. A conventional wireless personal phone 38 transmits and receives telecommunications signals to the wireless service provider transmitter receiver antenna 22 .
[0029] The wireless base phone 100 uses two sets of full duplex frequencies, meaning a minimum of four radio frequencies is required to operate the phone. The wireless base phone 100 will use one frequency to send to the wireless service provider antenna 22 and use a second frequency to receive from the wireless service provider. A third radio frequency will be used to send to the satellite (auxiliary) phones 200 while using a fourth frequency to receive from the satellite (auxiliary) phones 200 . The base phone 100 can also be equipped with a RJ-11 or similar type connector to send signals that have been converted from the radio frequency input from the wireless service provider to the satellite (auxiliary) phones 200 through the building's own internal wired network.
[0030] FIG. 3 elaborates on how the four frequencies are utilized by the Wireless Base-Phone 100 to achieve its applied functions. (Artisans skilled in the manufacture of cell phones and standard wired phones will appreciate that items in the drawing are illustrated for simplicity. Note the items are not drawn to scale in any of the figures or drawings. Well-understood and common elements that are used in the creation of a commercially feasible product are not typically depicted in order to depict a less cluttered view of different items of the Wireless Base-Phone invention.) As stated in the previous paragraph, two sets of full duplex frequencies are utilized by the Wireless Base-Phone 100 , meaning a minimum of four frequencies are required. In FIG. 3 , the artisan can see that frequency 1 represents the inbound transmission from the wireless service provider 22 , which is received by the Wireless Base-phone 100 . The frequency is converted to another frequency 3 , which is utilized to transmit to the satellite (auxiliary) phones 200 . The satellite (auxiliary) phones 200 transmit on frequency 4 back to the Wireless-Base Phone 100 . Frequencies 3 and 4 act as one pair of the full duplex frequencies and can use similar technology as the following for transmitting and receiving: GSM/CTS (Global System for Mobile Communications/Cordless Phone Telephony), DCS 1800 (Digital Cordless Standard), DECT (Digital European Cordless Phone Technology), or other newer or similar cordless technologies can be used for this aspect of the Wireless Base Phone 100 to/from the satellite (auxiliary) phone 200 operation. The Wireless Base-Phone 100 receives the transmission (frequency 4 ) from the satellite (auxiliary) phone 200 , which converts frequency 4 to frequency 2 . Frequency 2 is then transmitted from the Wireless Base-Phone 100 to the Wireless service provider 22 . In this example, frequencies 1 and 2 act as one pair of the full duplex frequencies, which utilize standard wireless service provider technologies such as: Advanced Mobile Phone System (AMPS, Analog), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA) or any of its derivatives such as CDMA2000 and CDMA2000 1XEV, Global Systems for Mobile communications (GSM), Personal Communications Services (PCS), and any new or newer technologies that will be used in the future for wireless phone communication.
[0031] FIG. 4 depicts how the Wireless Base Phone can be utilized with Voice over Internet Protocol (VoIP) or similar technologies. In this example, a third party vendor will supply an appropriate adaptor 39 that can take information from the internet and convert it to an output transmit frequency 1 . Frequency 1 is received by the Wireless Base-Phone 100 and converted to frequency 3 , which is transmitted to the satellite (auxiliary) phone 200 . The satellite (auxiliary) phone 200 transmits on frequency 4 back to the Wireless Base-Phone 100 , which converts frequency 4 to frequency 2 , which it transmitted back to the Voice over Internet Protocol (VoIP) technology adapter 39 . Note, that in this scenario all the frequencies will most likely utilize but are not limited to GSM/CTS (Global System for Mobile Communications/Cordless Phone Telephony), DCS 1800 (Digital Cordless Standard), DECT (Digital European Cordless Phone Technology), or other newer or similar cordless technologies.
[0000] Description of How the Wireless Phone Base Achieves its Results
[0032] The wireless phone base 100 achieves its results by acting as a wireless receiver from a wireless service provider or as a transmitter to a wireless service provider just as any personal wireless phone in use today that individuals carry on their person does.
[0033] It also transmits and receives radio/wireless signals to nearby satellite (auxiliary) phones 200 linked to it.
[0034] FIG. 1 depicts a wireless base phone 100 . The base phone is not similar to other phones in that it is not designed with an RJ-11 or similar type connector (not shown) that is used to connect the phone to the present wired telecommunications system network (PSTN). Instead the wireless base phone 100 has a built in wireless receiver/transmitter and antenna 18 , similar to personal wireless phones that allow the base phone to connect to transmit and receive to and from a wireless service provider's network and to receive and transmit to the satellite (auxiliary) phones 200 .
[0035] The wireless base phone 100 has a the following additional items; a hand set 11 that is either connected to the phone base 10 with a conventional cord 19 or is cordless, the handset 11 has the typical ear speaker 12 that emits audio and a microphone 14 used to pick up audio transmissions. The handset 11 also has a conventional keypad 13 or rotary dialing (not shown) for dialing telephone numbers or for entering text messaging. The handset can have many other options that are not shown here but can be found on many telephones.
[0036] The wireless base phone 100 is similar to present desktop, countertop, and wall-mounted phones. They can be placed in central locations that are easy to locate. The hand set 11 is larger than a personal wireless cell phone 38 ; therefore, it is easier to handle and use while the phone base 10 contains large sized features that are easy to distinguish and use. The wireless base phone 100 is more convenient since it comes with additional satellite (auxiliary) phones 200 that can be placed throughout a structure, building, or house even if a RJ-11 connector is not readily available since the wireless base phone 100 and satellite (auxiliary) phone 200 or phones communicate with full duplex (if so designed spread spectrum) radio frequency capabilities.
[0037] The wireless phone base 10 also comes with a conventional electrical power cord 17 attached to a conventional power outlet plug 15 to provide electrical input to power it and or to power a battery charger (not shown) for a cordless handset 11 , if so designed. The phone base 10 has an antenna 18 and a receiver/transmitter (not shown) built into it for transmitting and receiving radio/wireless transmissions from a wireless service provider, represented here by transmitter/receiver antenna 22 , and for receiving and transmitting to its, if so designed, conventional cordless handset 11 equipped with antenna 16 , and for transmitting and receiving to corded or cordless satellite phones 200 . The phone base 10 acts as a transfer point for radio transmissions from/to the wireless service provider and from/to the satellite phones 200 . Note the phone base 10 and its satellite phones 200 are linked together similar to present conventional cordless phone packages that transmit from/to each other within the linked/associated phone system using full duplex radio frequency (if so designed, spread spectrum capability).
[0038] The satellite (auxiliary) phone 200 can come in various configurations.
1. The handset 26 can have a cord 19 that attaches it to the base 24 and can be designed with the same features as described for handset 11 as well as having additional features that many phones come with but are too many to list here for the purposes of this patent application. The receiver/transmitter (not shown) can be built into the handset 26 or base 24 . The antenna ( 25 ) can be built into the handset 26 or the base 24 . The satellite (auxiliary) phone 200 receiver/transmitter receives radio frequency transmissions from the wireless base phone 100 and transmits back to the wireless base phone 100 . GSM/CTS (Global System for Mobile Communications/Cordless Phone Telephony), DCS 1800 (Digital Cordless Standard), DECT (Digital European Cordless Phone Technology), or other newer or similar cordless technologies can be used for this aspect of the Wireless Base Phone 100 to satellite (auxiliary) phone 200 operation. 2. The satellite (auxiliary) phone 200 can be cordless. In this case the handset 26 set has an antenna 25 and the receiver/transmitter (not shown) is built into it. The base 24 has a battery-recharging (not shown) unit built into it for the handset 26 . The receiver/transmitter receives radio frequency transmissions from the wireless base phone 100 and transmits back to the wireless base phone 100 . GSM/CTS (Global System for Mobile Communications/Cordless Phone Telephony), DCS 1800 (Digital Cordless Standard), DECT (Digital European Cordless Phone Technology), or other newer or similar cordless technologies can be used for this aspect of the wireless base phone 100 to satellite (auxiliary) phone 200 operation. 3. The satellite (auxiliary) phone 200 can be cordless with a receiver/transmitter (not shown), battery charger (not shown), and antenna (not shown) built into the base 24 . The handset 26 will also have a receiver transmitter built into it as well as an antenna 25 . The receiver/transmitter in the base 24 will communicate with both the wireless base phone 100 and the handset 26 . The receiver/transmitter in the base 24 will use two sets of full duplex (if so designed, spread spectrum technology) radio frequencies. One frequency to transmit to the base phone 100 and a second frequency to receive from a base phone 100 . The third frequency transmits to the handset 26 and the fourth receives from the handset 26 . This configuration allows for a larger transmitter receiver to be built into the base 24 so it can be set at longer distances from the wireless base phone 100 . GSM/CTS (Global System for Mobile Communications/Cordless Phone Telephony), DCS 1800 (Digital Cordless Standard), DECT (Digital European Cordless Phone Technology), or other newer or similar cordless technologies can be used for this aspect of the wireless base phone 100 to satellite (auxiliary) phone 200 operation.
[0042] FIG. 2 depicts an overall view of how the Wireless Base-Phone system works. The wireless base phone 100 has a conventional radio/wireless receiver transmitter similar to the ones used in personal wireless phones 38 that people carry with them and is used to connect to a wireless service provider system. The base phone 100 also has a conventional radio/wireless receiver transmitter that is used to transmit and receive from/to satellite (auxiliary) phones 200 that are linked to it similar to conventional phone packages that can be currently purchased.
[0043] For example, a wireless service provider can package the wireless base phone 100 in a family plan as the first phone. This wireless base phone 100 can have the home or business's original phone number transferred to it due to new phone number portability legislation. The wireless-phone service provider can then sell additional personal wireless phones 38 under family plans. The wireless base phone 100 can also be sold with additional satellite (auxiliary) phones 200 that the consumer can put throughout the house, business, building or structure.
[0000] Alternative Methods of Making the Wireless Base Phone
[0044] There are alternative methods in which the wireless base phone may be set up, as discussed below.
The wireless base phone can have an RJ-11 or similar connector so the consumer can choose whether to use it with the standard wired telecommunications network or with a wireless provider. The wireless base phone can be set up with an RJ-11 or similar type connector that will send out and receive telecommunications signals to other associated/linked phones within the building's wired network. Note the buildings wired network is not connected to the outside wired telecommunications network (PSTN). The base phone will receive transmitted signals from the wireless provider and then send the signals through the building's internal wired network. Linked or associated phones can then send telecommunication signals back to the base phone through the building's internal wired network, which will then transmit the telecommunications signals to the wireless provider. The wireless base phone can be devised in such a way that it can be mounted onto a wall and does not necessarily have to sit on a horizontal or nearly horizontal surface. The wireless base phone can be made using any of a number of industry standard wireless technologies such as, Advanced Mobile Phone System (AMPS, Analog), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA) or any of its derivatives such as CDMA2000 and CDMA2000 1XEV, Global Systems for Mobile communications (GSM), Personal Communications Services (PCS), and any new technologies that will be used in the future for wireless phone communication. The phones can be made using dual band, tri-band, dual mode, or any combination of the mentioned methods can be used. The phones can be set up as a Wi-Fi, WiMax (802.16a), or Ultra Wide band receiver transmitter or can use Voice Over Internet Protocol (VoIP) technology to send and receive phone calls over the Internet. These phones can incorporate 2G (Second Generation), 2.5G (Second and half Generation), 3G (Third Generation), 4G (Forth Generation) or newer standards and 802.11 a, b, g, super g, or similar or newer technology standards. See FIG. 4 for an example of how the Wireless Base-Phone can be used in conjunction with the Voice over Internet Protocol (VoIP) technology. GPS (Global Positioning System) can also be incorporated into the phone as well.
[0051] In addition, by eliminating the wired communications phone cost the consumer will save money. Following is an example of the potential savings. Please note this cost savings will vary between plans and options. Note purchase of phone hardware is not included in these estimates.
EXAMPLE 1
[0052] Assumptions—Family With Both Home Wired Phone Service and Wireless Service Plans.
Family of four Local home service through PSTN, which includes, $50.00 local phone service and $16.78 for long distance service provider, therefore, $50.00+$16.78=$66.78 per month excluding taxes Purchase of wireless family calling plan of $39.99 for the first phone and $9.99 for additional phones per month. Two wireless phones purchased; therefore, $39.99+$9.99=$49.98 monthly cost excluding taxes Total cost for both phone systems is $49.98+$66.78=$116.76 per month excluding taxes
EXAMPLE 2
[0058] Assumptions—Family of Four With Wireless Base Phone Family Plan.
Purchase the wireless base phone that stays at home for $39.99 monthly service cost and has previous wired phone number transferred to it due to phone number portability legislation. Purchase second portable wireless phone for $9.99 per month service charge for Dad. Purchase third portable wireless phone for $9.99 per month service charge for Mom. Total costs excluding taxes $39.99+$9.99+$9.99=$59.97 service charge per month
EXAMPLE 3
[0063] Savings Between Both Plans
[0064] Example 1−Example 2=$116.76−$59.97=$56.79 per month service charge excluding taxes.
[0065] The present invention allows the consumer to connect to a wireless telecommunications network, thereby allowing the consumer to not have to pay for access to a wired telecommunications network (PSTN) as well as access to a wireless telecommunications network.
[0066] Thus, the foregoing detailed description provides a wireless base phone that communicates with a service provider, and auxiliary (satellite) phone(s) that communicate with the base phone in a manner that enables effective, efficient and cost efficient phone service to a family and/or entity. With the foregoing disclosure in mind, various ways to provide such a phone system will be apparent to those in the art.
[0000] LIST OF REFERENCE NUMBERS
[0000]
100 Wireless Base Phone
10 . Wireless phone base
11 . Phone hand set, either corded or cordless
12 . Audio Speaker for phone
13 . Keypad
14 . Microphone
15 . Plug with power cord
16 . Hand Set Antenna
17 . Electrical power cord
18 . Base Phone Antennae
19 . Cord
20 . Display
21 . Telecommunications Tower
22 . Wireless Service Provider Transmit and Receive Antennae
200 . Satellite (Auxiliary) Phones
24 . Corded or Cordless phone docking base and or receive/transmit base
25 . Corded or Cordless Satellite (auxiliary) phone handset antenna
26 . Cordless Satellite (auxiliary) phone handset
32 . Building or structure
38 . Wireless personal phone
39 . adaptor
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A wireless base phone that connects to a wireless service provider and to associated satellite (auxiliary) phones is provided. The wireless base phone negates having to have the traditional phone at home or in a business that connects to traditional outside wired telecommunications network (PSTN). The consumer can save on not having to pay for this traditional wired network service. Instead, a consumer can purchase a wireless family plan or similar plan from a wireless service provider that allows for the purchase of several wireless phones at a low rate. One or more of the wireless phones is set up similar to traditional desktop, counter top, wall mounted, or similar type phones. This allows the consumer to place a wireless base phone or phones at their residence, business, or any other desired location. This wireless base phone can transmit to other wireless phones through the wireless service providers network. The base phone can also transmit and receive to/from nearby satellite (auxiliary) phones that are connected to it either with the buildings own internal wired network or though its own wireless transmit and receive capabilities.
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FIELD OF THE INVENTION
[0001] This invention concerns a dental x-ray apparatus and an associated method.
BACKGROUND OF THE INVENTION
[0002] In the field of dental radiology, taking cephalometric shots of the head of a patient with a facial and/or profile view is known.
[0003] Such images are obtained from an x-ray unit which includes an x-ray generator and an x-ray sensor. The sensor is placed facing the generator and the head of the patient is placed between the generator and the sensor.
[0004] The generator emits radiation in the form of a cone beam x-ray in the direction of the head of the patient and the sensor receives the radiation having irradiated the head.
[0005] This received radiation makes it possible to obtain a full projection of the cranium (hard tissue) of the patient which constitutes a cephalometric shot.
[0006] This projection is obtained by scanning the head of the patient in a continuous movement synchronized between a collimation slot and the sensor, for example, in the form of CCD linear array arranged behind the head.
[0007] This type of scanning takes approximately 10 seconds.
SUMMARY OF THE INVENTION
[0008] In order to reduce the cone effect of the x-ray beams which results in significant geometric distortions (the side of the cranium situated closest to the sensor is larger than the opposite side of the cranium), the sensor is placed at a distance that is sufficiently far away from the generator (for example 1.60 m, if not more) and the head of the patient is placed closer to the sensor than to the generator.
[0009] From one or more cephalometric shots, (profile, face . . . ) a practitioner, for example, an orthodontist, may establish a diagnosis as to the existence of certain defects needing to be corrected in the patient. The practitioner then takes the measures and/or carries out scans in order to determine what corrections are needed and the appropriate treatment.
[0010] To be able to preview the effects during the correction time and treatment foreseen on the patient's face, one or more photographs of the face will be taken.
[0011] Thus, in practice, the practitioner will take a photographic image, for example, of a profile view of the head of the patient, and will only retain the outline.
[0012] This image is then superimposed by software upon the cephalometric shot taken of a view of the profile of the patient's head.
[0013] From the moment in which the practitioner determines the corrections and the treatment adapted for the patient, he is able to simulate their effects on the face of the patient and display them.
[0014] More specifically, the software available to the practitioner enables him to display, upon a first image corresponding to the current state of the patient, the photographic image representing the soft tissue of the cranium (nose, lips . . . ) superimposed onto the cephalometric shot representing the hard tissue (bone, teeth . . . ).
[0015] The software then makes it possible, by calculation, from the data selected by the practitioner when he determines the corrections and the appropriate treatment, to accordingly reshape the cephalometric shot in order to simulate the corrections and the treatment selected for the hard tissue that will take place over time.
[0016] The photographic image will also be reshaped in the corresponding manner by a morphing algorithm.
[0017] The software also allows one to view a second image by superimposing the reshaped photographic image and the cephalometric image and that represents the evolution of the patient's head after the corrections and treatment.
[0018] In this way, the evolution of the treatment may be pre-controlled by visualizing the two images simultaneously.
[0019] However, so that the photographic and cephalometric images may be superimposed in a satisfactory manner, the applicant discovered that the images must be taken at the same angle of view.
[0020] Furthermore, the X-ray generator is equipped with a collimator the dimensions of which are calculated to adapt to a head having average dimensions.
[0021] However, the applicant has discovered that human heads widely range in size.
[0022] Thus, for a person with a head that is larger than the aforementioned average dimensions, the cephalometric images would show a truncated skull.
[0023] On the other hand, cephalometric image(s) obtained for a head whose dimensions are smaller than the average dimensions will show the entire skull as well as an area of the outline that is unnecessary.
[0024] As a result, the person will receive an overdose of unnecessary radiation.
[0025] This invention seeks to remedy at least one of the disadvantages mentioned above by proposing a dental radiology device including:
[0026] an X-ray generator adapted to generate an X-ray beam in the direction of a patient's head,
[0027] means of collimation adapted to confer the generated given dimensions to the X-ray beam;
[0028] a sensor placed facing the generator, receiving the projection of the collimated beam of radiation having irradiated the patient's head and providing a cephalometric image of the head of the patient,
[0029] characterized in that the device includes:
[0030] a means to acquire a photographic image of the patient's head,
[0031] a means of automatic control for the means of collimation as a function of the at least one photographic image so that the dimensions of the collimated X-ray beam are adjusted to the dimensions of the patient's head.
[0032] By acquiring one or more photographic images of the patient's head, and, more specifically, of his/her profile and by collimating the x-ray beam so that it interlocks with the image or the photographic images thus acquired, it is possible to adjust the dimensions of the collimated beam to the dimensions of the patient's head, and, more specifically, to the dimensions of his/her profile.
[0033] A photographic image or photograph of the head of a patient captures the visible parts of the head and face, and in particular, the contour of the head (in a facial or profile view). In general, such an image is thus representative of the soft tissue of the patient's head (nose, lips . . . ). Such an image does not capture the hidden parts of the head and which represent in particular the hard tissue (bone, teeth . . . ). These parts are in fact captured by the radiological sensor which receives the x-ray that irradiated the patient's head. Such a sensor provides a cephalometric image of the head of the patient which is thus different from the aforementioned photographic image.
[0034] It should be noted that the means of acquiring the photographic image(s) are separate from the radiation sensor which form a means to acquire the cephalometric image(s).
[0035] According to one characteristic, the sensor is a pixel matrix surface sensor with dimensions that encompass the dimensions of the x-ray beam projection having irradiated the head of the patient. The acquisition of the radiological projection is performed instantly.
[0036] According one characteristic, the X-ray generator includes an X-ray emission chamber; the means of acquiring at least one photographic image is positioned as close as possible to the chamber.
[0037] By placing the means of image acquisition as close as possible to the x-ray chamber, one is assured thusly that the photographic and the cephalometric images will be taken at the same angle or, at any rate, at a very close angle taking into account given the distance between the x-ray emission chamber and the patient's head is relatively remote.
[0038] It is advisable to note that the distance between the means of acquisition of at least a photographic image and the emission chamber should be short compared to the distance between the chamber and the patient head.
[0039] This distance should be for example within a ratio of 1 to 15.
[0040] According to one characteristic, the means of collimation includes a collimator with an adjustable slot.
[0041] It is thus particularly easy to automatically control the means of collimation in function of the photographic image(s) acquired by carrying out the adjustment of the slot in an appropriate manner.
[0042] According to one characteristic, the adjustable slot collimator comprises the means to adjust the length of the slot perpendicularly between them.
[0043] According to one characteristic, the means for adjustment is directionally independent, which gives great flexibility to the adjustment.
[0044] According to one characteristic, the adjustable slot is delimited by four edges that slide in a manner that is independent from each other.
[0045] According to one characteristic, the equipment includes means to obtain the outline of the patient's head from which at least one photographic image is acquired.
[0046] This outline contains sufficient information to allow automatic control of the means of collimation.
[0047] According to one characteristic, the means of automatic control is adapted to automatically control the means of collimation in function of the dimensions of the outline of the patient's head so that the dimensions of the collimated x-ray beam are adjusted to the dimensions of the outline of the patient's head.
[0048] Dimensions of the collimated beam, and in particular the width of the beam at its base which is close to the emission chamber, can be controlled according to the contour of the head of the patient thus obtained.
[0049] This makes it possible to adjust the dimensions of the collimated beam to the dimensions of the outline of the patient's head.
[0050] The invention also has for its object a method, correspondingly, a method to produce a cephalometric image of the head of a patient comprising the following stages:
[0051] generation by an X-ray generator of an X-ray beam in the direction of a patient's head,
[0052] collimation of the x-ray beam generated in order to confer to it the given dimensions,
[0053] reception by a sensor facing the radiological projection of the collimated beam which irradiated the head of the patient,
[0054] provision of a cephalometric image from the received radiological projection,
[0055] characterized in that the method also comprises the following stages:
[0056] acquisition of at least one photographic image of the patient's head,
[0057] automatic control of the collimation of the x-ray beam in function of said at least one photographic image in order for the dimensions of the collimated x-ray beam to be adjusted to the dimensions of the patient's head.
[0058] The process according to the invention has the same advantages as those described briefly above in reference to the dental x-ray unit and therefore, will not be repeated here.
[0059] According to one characteristic, the sensor is a pixel matrix surface sensor with dimensions that encompass the dimensions of the x-ray beam projection having irradiated the head of the patient, as the acquisition of the radiological projection being performed instantly.
[0060] According to one characteristic, the automatic control stage of the collimation of the x-ray beams as a function of said at least one photographic image includes the adjustment of the dimensions of the beam.
[0061] According to one characteristic, the x-ray generator includes an x-ray emission chamber, the acquisition of said at least one photographic image being performed from a position that is as close as possible to the chamber.
[0062] According to one characteristic, the automatic control stage of the x-ray beam as a function of said at least one photographic image includes the adjustment of the dimensions of the beam.
[0063] According to one characteristic, the adjustment of the dimensions of the beam comprises more in particular, the means to adjust the length of the collimation slot perpendicularly between them.
[0064] According to one characteristic, the method includes means to obtain the outline of the patient's head from which at least one photographic image is acquired.
[0065] According to one characteristic, the automatic control of the collimation is performed as a function of the dimensions of the outline of the patient's head so that the dimensions of the collimated x-ray beam are adjusted to the dimensions of the outline.
BRIEF DESCRIPTION OF THE DRAWINGS
[0066] The other characteristics and advantages will be better apparent through the description that follows, given only as a non-restrictive example and made in reference to the attached drawings in which:
[0067] FIG. 1 is a general diagrammatic view of the device in accordance with the invention;
[0068] FIGS. 2 a and 2 b respectively illustrate the means of collimation used in the device of FIG. 1 ;
[0069] FIG. 2 c diagrammatically illustrates a collimation slot obtained with the means of FIGS. 2 a and 2 b;
[0070] FIG. 3 a diagrammatically illustrates a view of the surface of the end of the device of FIG. 1 ;
[0071] FIG. 3 b shows in a diagrammatical fashion the layout of the means of acquisition of a photographic image, of the x-ray emission chamber, of the head of a patient and of the sensor;
[0072] FIG. 4 illustrates an algorithm of the method to produce a cephalometric image;
[0073] FIGS. 5 a and 5 b shows in a diagrammatical fashion the radiological project of a beam irradiating a patient's head with the un-adjusted edges of a collimator;
[0074] FIGS. 5 c and 5 d show in a diagrammatical fashion the radiological project of a beam irradiating a patient's head with the adjusted edges of the collimator;
[0075] FIG. 6 illustrates in a diagrammatical fashion the superposition of the cephalometric and photographic images;
[0076] FIG. 7 illustrates in a diagrammatical fashion an enlarged view of a part of the image of FIG. 6 ;
[0077] FIG. 8 illustrates in a diagrammatical fashion the hard tissue of the cephalometric image reshaped by calculation;
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0078] As shown in FIG. 1 and designated by the noted general reference ( 10 ), a dental x-ray unit according to the invention is a cephalometric type of device. This device allows cephalometric images or shots to be produced of the head of a human being. The device includes a fixed frame ( 12 ), for example a vertical bracket aligned along the axis Z, on which an x-ray unit ( 14 ) is assembled which will now be described.
[0079] This unit includes a structure ( 16 ) comprising a horizontal beam ( 16 a ) which forms a support that comprises, on one end, a vertical arm ( 16 b ) dropping from the horizontal beam, and, at the opposite remote end, an arm ( 16 c ) that is both horizontal and vertical.
[0080] A source or generator of x-rays ( 18 ) is fix mounted on the arm ( 16 b ), while an x-ray sensor ( 20 ) is mounted on the remote arm ( 16 c ) which allows the sensor to be positioned at a good distance from the generator, for example at 4 m from it.
[0081] The generator ( 18 ) and the sensor ( 20 ) are thus placed facing each other and are placed in a fixed geometric relation with respect to each other.
[0082] The structure ( 16 ) that acts as a support for the generator ( 18 ) and the sensor ( 20 ) constitutes the core of the x-ray unit ( 14 ).
[0083] The x-ray device ( 10 ) also comprises a positioning device ( 21 ) fixed upon the arm ( 16 c ) in front of the sensor ( 20 ) and which makes it possible to immobilize the head of the patient while the x-ray films are taken, during the operation of the equipment. The head is placed between the generator ( 18 ) and the sensor ( 20 ). More specifically, the device ( 21 ) comprises one part, a vertical descending positioner ( 21 a ) the two branches of which have free ends which are opposite each other, and designed to be positioned in the ears of the patient and, another part, a descending vertical beams ( 21 b ), designed to come into contact with the forehead of the patient in order to prevent back and forth movement of the head.
[0084] The x-ray generator is equipped with a support ( 22 ), placed against the face of the generator that is opposite the sensor ( 20 ) and within which an opening for the output of X-rays from the generator is arranged.
[0085] The support is positioned in from of this x-ray output opening and comprises the means of collimation that will be described in reference to FIGS. 2 a and 2 b.
[0086] The collimated x-ray beam has a cone form ( 23 ) that was truncated by its passage through the slot opposite the rectangular section. This beam is positioned on its base (in a section parallel to the plane of the slot), along a direction that corresponds to the direction in which the slot is laid out.
[0087] The sensor ( 20 ) fastened to the arm ( 16 c ) is positioned opposite the generator ( 18 ). It is capable, on the one hand, to receive the x-ray coming from the generator and having irradiated the object (patient's head) placed between the generator and the sensor and, on the other hand, to convert this x-ray which has been attenuated by its passage through the object into an electrical signal representative of an x-ray image of this object.
[0088] It should be noted that the sensor consists of a pixel matrix which is arranged in correspondence with the beam emitted from the collimation slot.
[0089] This sensor is, for example, a form of a phosphor scintillator including the active surface pixel matrix and its dimensions are for example, 30 cm (height)×30 cm (width). The pixel matrix have for example a size of 150 pm and thus form a matrix of 2000×2000 pixels. Alternately, the sensor is constituted of a pixel matrix with a CCD-type charge-transfer with a size of, for example, 5 cm×5 cm and which is provided with an optical focus with an optical zoom of 6. The design includes an electronic control and power supply located behind it.
[0090] FIGS. 2 a and 2 b show the means of collimation ( 30 ) which enables the collimation slot to be geometrically variable.
[0091] The means for adjustment is set up so that it is able to change, on command, the geometry of the slot and, in particular, its length along two directions which are perpendicular to each other, for example, horizontal and vertical.
[0092] More specifically, the adjustment means adapted to change the length of the slot along one direction is independent of those adapted to change the length in the other direction, offering thusly greater flexibility in the adjustment.
[0093] In the example illustrated, the x-ray equipment comprises four independent means of adjustment ( 50 , 52 , 54 , 56 ) to independently change the position of each of the four edges ( 58 , 60 , 62 , 64 ) defining the collimation slot.
[0094] On the support positioned in front of the output window of FIG. 1 , are successively superimposed the arrangement ( 30 a ) of FIG. 2 a , then that ( 30 b ) of FIG. 2 b.
[0095] These arrangements are not shown in a superimposed fashion for reasons of clarity.
[0096] More specifically, the arrangement ( 30 a ) of FIG. 2 a comprises two edges ( 58 , 60 ) of two plates ( 66 . 68 ) placed opposite of each other (for example rectangular in shape) and which are each attached respectively to another plate ( 70 , 72 ) positioned perpendicularly.
[0097] Each pair of plates ( 66 , 70 and 68 , 72 ) form in this way an L or an L turned 180°.
[0098] The second plate ( 70 , 72 ) of each pair is supplied, on one of its edges which is opposite to the one against which the first plate is fixed, with a longitudinal row of teeth ( 74 , 76 ).
[0099] A means of moving the edge ( 58 ) (respectively 60 ) comprising a motor ( 50 ) (respectively 52 ) equipped with a toothed sprocket ( 78 ) on the output shaft (respectively 80 ).
[0100] This sprocket works with the teeth ( 76 ) (respectively 74 ) to cause the movement of plates ( 72 and 68 ) in the direction D 1 in either direction depending on the direction of rotation of the sprocket.
[0101] A light guide ( 82 ) (respectively 84 ) is provided for on the second plate ( 72 ) (respectively 70 ) and two guide pins ( 86 , 88 ) (respectively 90 , 92 ) interdependent with the aforementioned support are positioned in this groove to guide the movement longitudinally of the corresponding plate and therefore the corresponding edge.
[0102] This arrangement allows, by adjusting the space between the opposing edges ( 58 and 60 ) in direction D 1 , adjusting one of the dimensions of the slot and thus its length in one direction.
[0103] In the identical manner, the arrangement shown in 30 b in FIG. 2 b allows, by adjusting the space between the opposing edges ( 62 and 64 ) in direction D 2 , adjusting one of the dimensions of the slot in the other direction.
[0104] Thus, by bringing the edges ( 62 and 64 ) closer and by moving the edges ( 58 and 60 ) apart of the slot in a lengthwise fashion along direction D 1 . A slot that follows along axis Z shown in FIG. 2 c is obtained in this manner.
[0105] To the contrary, if the edges ( 62 and 64 ) are moved apart and edges ( 58 and 60 ) are brought together, the lengthwise shape of the slot is carried out along direction D 2 . One thus obtains an elongated slot following an axis perpendicular to axis Z.
[0106] We can also adjust the spacing of opposite edges ( 58 , 60 ) and ( 62 , 64 ) in order to obtain a slot in the form of a square or close to such a form.
[0107] The different elements shown in FIG. 2 b , i.e., the first and second plates ( 100 , 102 ) (respectively 104 , 106 ), the grooves ( 108 ) (respectively 110 ), the motor ( 54 ) (respectively 56 ) and its toothed sprocket ( 116 ) (respectively 118 ), as well as the guide pins ( 120 , 122 ) (respectively 124 , 126 ) in the guide light ( 128 ) (respectively 130 ) are identical to their corresponding parts in FIG. 2 a but that are only shifted 90°.
[0108] The equipment of FIG. 1 also comprises, as shown in FIG. 3 a (front view of the arm 16 b ), the means of acquisition ( 132 ) of at least one photographic image of the object placed between the x-ray generator and the sensor, i.e., the patient's head.
[0109] In FIG. 3 a , on the lower part of the arm ( 16 b ), the support ( 22 ) placed in front of the generator ( 18 ), is also shown, as well as the means collimation ( 30 ) shown with a dotted line and a collimation slot ( 133 ) placed before the x-ray output slot.
[0110] The acquisition means ( 132 ) which take, for example, the form of a digital image capture device (such as a photographic camera fitted with a lens ( 134 )) are positioned as close as possible to the x-ray emission chamber. In the example of FIG. 3 a , the means ( 132 ) are placed above the generator and are shifted laterally with respect to the latter. Nevertheless, other layouts are possible, based on the constraints of the environment.
[0111] These means ( 132 ) are also represented in FIG. 3 b by letter A, while the emission chamber is represented by the letter F.
[0112] The distance between these means of photographic image acquisition and the generator chamber is small in comparison with the distance L between the chamber and the sensor ( 20 ).
[0113] As an example, distance d is equal to 5 cm and distance L is equal to 170 mm.
[0114] Thus, by positioning the means of image acquisition as close as possible to the generator chamber, in light of the available space around the means of collimation placed in front of the of x-ray emission slot, we ensure that the angle under which the photographic image(s) of the head of the patient are taken is very close to the angle at which the cone x-ray beam is emitted viewed from the sensor.
[0115] As an example, a shift of less than 5 degrees will give good results.
[0116] Correspondingly, the photographic image of the patient's head, and the cephalometric image are superimposable.
[0117] As diagrammatically illustrated in FIG. 3 b , the photographic and cephalometric images are provided respectively by the means of acquisition (A) and by the sensor ( 20 ) to a data processing unit ( 136 ) including a means for storing the images.
[0118] A screen ( 140 ) to display the images acquired individually and superimposed is also connected to the processing unit.
[0119] The processing unit ( 136 ) and the display means ( 140 ) make part of the x-ray equipment illustrated in FIG. 1 .
[0120] The processing unit ( 136 ) ensures control of the operation of the equipment ( 10 ).
[0121] This unit may be, for example, a PC computer.
[0122] It should be noted that the dimensions of the pixel matrix of the sensor ( 20 ) encompass the dimensions of the x-ray beam projection that irradiated the head (P) of the patient.
[0123] FIG. 4 represents an algorithm outlining the main stages of a method according of the invention and that may be implemented for example, by the equipment ( 10 ).
[0124] This algorithm is for example, is stored in a memory area of the processing unit ( 136 ) and is run on command.
[0125] To implement the method according of the invention, the patient should be placed between the x-ray generator and the sensor illustrated in FIG. 1 and that his/her head should be immobilized close to the sensor, in other words, at a good distance from the generator, for example, around 150 cm.
[0126] When the practitioner starts the equipment, for example from a keyboard and a pointing interface such as a mouse, which are not shown in the figures but that interact with the processing unit ( 136 ) and the screen ( 140 ) of FIG. 3 b , a mode of acquisition of one or more photographic images of the patient's head (face view or profile view) is started during a first stage (S 1 ).
[0127] The image(s) are stored.
[0128] Through the second stage (S 2 ), processing of an image is provided for in order to preserve only the outline of the patient's head.
[0129] In fact, these outlines are sufficient to supply the necessary information to the equipment user.
[0130] This processing is performed by the processing unit ( 136 ) which determines the dimensions of the outline of the head, among other things.
[0131] The algorithm comprises a third stage (S 3 ) controlling the means of collimation with respect to the photographic image(s) acquired in stage S 1 and, in particular, the dimensions of the patient's head obtained in stage S 2 .
[0132] This ensures that the dimensions of the X-ray beam emitted by the chamber (F) and collimated by the means of collimation are adjusted to the dimensions of the outline of the patient's head.
[0133] Thus, the cephalometric image(s) that one wishes to carry out using the equipment will be perfectly adapted to the dimensions of the patient's head.
[0134] Correspondingly, the patient's head will not be truncated on the image(s) and the patient will not receive useless doses of radiation as was the case in the past.
[0135] From the practical point of view, control of the means of collimation consists of setting the dimensions of the x-ray beam so that it is adapted to the dimensions of the outline of the patient's head.
[0136] This setting includes, more in particular, the adjustment of the length of the collimation slot of the means 30 a and 30 b illustrated in FIGS. 2 a and 2 b , in a perpendicular direction between them. This setting is controlled by the processing unit ( 136 ) of FIG. 3 b from the dimensions of the outline of the head calculated in stage S 2 .
[0137] Optionally, the algorithm may include a stage S 3 a of display on the screen ( 140 ) of the edges of the collimation slot projected once it is set to the dimensions of the outline of the patient's head, and that are superimposed upon the outline of the head.
[0138] This stage of display makes it possible to ensure that the automatic control of the collimator at the patient's head is correct and may be validated during stage S 3 b.
[0139] Under the hypothesis where the edges of the collimation slot shift, it will not be adapted to the dimensions of the outline of the patient's head, or perhaps that this shift will be too great or too small with respect to the head, stage S 3 b also provides for the modification of the setting of the collimation slot in order to obtain an adjustment with respect to the outline of the patient's head. Alternatively, stage S 3 b makes it possible to return to the collimation slots pre-programmed by default.
[0140] Stage S 3 b is then followed by the display stage S 3 a so that the user of the device may see the new setting which has been carried out.
[0141] Then, stage S 3 b is performed again so the user can validate the setting.
[0142] The algorithm then comprises an S 4 stage of the emission of the cone x-ray beam, this beam being collimated by the collimation slot the setting of which was obtained and validated in stage S 3 .
[0143] Thus, the collimated beam is perfectly adapted to the dimensions of the outline of the patient's head.
[0144] FIG. 5 a shows the display on the screen of the patient's head (P) and of the cone projection of the edges of the slot when the automatic control according to the invention has not been performed.
[0145] FIG. 5 b shows the position corresponding to the edges of the slot, of the head, and of the sensor in the layout shown in FIG. 3 b.
[0146] In this position, the patient receives an overdose of radiation.
[0147] FIG. 5 c shows the display on the screen of the head (P) of the cone projection of the edges of the slot after the automatic control with respect to the photographic image has been previously performed.
[0148] The means of collimation is represented in FIG. 5 d in an adjusted position obtained through the automatic control.
[0149] The configuration of the x-ray beam is thus adapted to the patient's head and the latter receives an optimal dose of radiation. The x-ray projection of the beam which irradiated the head is recorded on the active surface of the sensor ( 20 ).
[0150] Stage S 5 provides for the acquisition of one or more cephalometric images of the patient's head. This or these images are acquired instantaneously so that the patient has no opportunity to move, thus avoiding distortions. It should be noted that a shot will be taken, for example, in ½ s.
[0151] In the embodiment described, the photographic and cephalometric images correspond to views of the profile of the patient's head.
[0152] In stage S 6 , after acquiring a cephalometric image ( 150 ), the superimposition of the cephalometric image ( 150 ) and the photographic image ( 160 ) is provided for as shown in FIG. 6 .
[0153] The photographic image ( 160 ) makes the soft tissue of the patient's head (nose, lips, chin . . . ) appear, while the cephalometric image ( 150 ) reveals the hard tissue (bone, teeth . . . ).
[0154] It should be noted that the superimposition of images is carried out in a particularly reliable and accurate manner due to positioning the means of acquisition of the photographic image at a very short distance from the X-ray emission chamber.
[0155] It should be noted that superimposing the photographic image onto the cephalometric image needs to apply a geometric conversion based on recognition of the profile and target point in order to get a perfect match. For example, we can use the device's ( 21 ) patient support arms in FIG. 1 for this purpose.
[0156] As already mentioned, views from the sensor ( 20 ) illustrated in FIG. 3 b , the two photographic and cephalometric images may be considered to have been taken at the same camera angle.
[0157] An almost perfect line up between the two images makes it possible to correctly position within the same view ( FIG. 6 ) both the soft tissue and the hard tissue in relation to each other.
[0158] This superimposition of images is followed by step S 7 of viewing the images thus superimposed which is shown in the aforementioned FIG. 6 .
[0159] This display takes place, for example, on the screen ( 140 ) of FIG. 3 b.
[0160] The image thus obtained on the display screen allows the practitioner, for example, an orthodontist, to establish a diagnosis by identifying certain defects needing to be corrected, for example, in the patient's jaw.
[0161] He may thus determine the corrections that will be provided to the jaw as well as the appropriate treatment.
[0162] In the example shown in FIG. 6 , and shown as a magnified view in FIG. 7 , the implantation of the incisor ( 170 ) in the jaw of the patient is such that the latter is particularly inclined from the vertical toward the front of the patient's mouth, which causes a deformation of the upper lip ( 172 ).
[0163] In the same way, the tooth ( 174 ) is implanted in the lower jaw in such a way that it is strongly tilted towards the vertical direction in the front of the mouth, which also causes a deformation of the lower lip ( 176 ).
[0164] On the basis of this report, the practitioner will take measures and possibly scans in order to determine the corrections to be made to the jaw of the patient, as well as the appropriate treatment (for example, installation of an appliance in order to correct the position of the teeth ( 170 and 174 )).
[0165] This stage corresponds to stage S 8 of the algorithm.
[0166] The following stage S 9 makes it possible to display, as a preview, the effects through time of the treatment recommended by the practitioner for the patient's jaw.
[0167] The reshaping of the hard tissue in the cephalometric image is obtained by calculation, from the data selected by the practitioner when he determines the corrections to be made and the appropriate treatment,
[0168] This stage is performed by the processing unit ( 136 ) and corresponds to running an algorithm of a known type and available on the market. For example software marketed by the company Practice Works would work.
[0169] The effects thus simulated on the hard tissue of the cephalometric image are illustrated in FIG. 8 .
[0170] Similarly, the manner in which the soft tissues (the lips in particular) are distorted correspondingly over time is obtained through a morphing algorithm, of a known type, which is also implemented by the processing unit ( 136 ).
[0171] The display of the effects thus simulated on the soft tissues of the patient is also illustrated in FIG. 8 corresponding to the superimposition of the two images, after reshaping each of them.
[0172] It should be noted that the reshaping of the hard tissue in the cephalometric image and the reshaping of the soft tissues of the photographic image are performed independently from each other insofar as, in the image of FIG. 6 , the superimposition of the two images is shown, each of them correspond to a set of separate data and thus it is possible to process them separately.
[0173] Due to the display of this simulation, the practitioner, as well as the patient, are both able to appreciate the impact of the treatment recommended by the practitioner, in a particularly realistic manner.
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A dental x-ray unit comprising: an X-ray generator adapted to generate an X-ray beam in the direction of a patient's head, means of collimation adapted to confer given dimensions to the generated X-ray beam; a sensor placed facing the generator, receiving the radiologic projection of the collimated beam having irradiated the patient's head and supplying a cephalometric image of the patient's head, characterized in that the device includes: the means to acquire at least one photographic image of the patient's head, the means of automatic control for the means of collimation according to the at least one photographic image so that the dimensions of the collimated X-ray beam are adjusted to the dimensions of the patient's head.
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This is a divisional application of application Ser. No. 08/066,188, filed on May 21, 1993 now U.S. Pat. No. 5,411,636.
BACKGROUND OF THE INVENTION
In the manufacture of tissue products, it is generally desireable to provide the final product with as much bulk as possible without compromising other product attributes. However, most tissue machines operating today utilize a process known as "wet-pressing", in which a large amount of water is removed from the newly-formed web by mechanically pressing water out of the web in a pressure nip between a pressure roll and the Yankee dryer surface as the web is transferred from a papermaking felt to the Yankee dryer. This wet-pressing step, while an effective dewatering means, compresses the web and causes a marked reduction in the web thickness and hence bulk.
On the other hand, throughdrying processes have been more recently developed in which web compression is avoided as much as possible in order to preserve and enhance the bulk of the web. These processes provide for supporting the web on a coarse mesh fabric while heated air is passed through the web to remove moisture and dry the web. If a Yankee dryer is used at all in the process, it is for creping the web rather than drying, since the web is already dry when it is transferred to the Yankee surface. Transfer to the Yankee, although requiring compression of the web, does not significantly adversely affect web bulk because the papermaking bonds of the web have already been formed and the web is much more resilient in the dry state.
Although throughdried tissue products exhibit good bulk and softness properties, throughdrying tissue machines are expensive to build and operate. Accordingly there is a need for producing higher quality tissue products by modifying existing, conventional wet-pressing tissue machines.
SUMMARY OF THE INVENTION
It has now been discovered that the bulk of a wet web can be significantly increased with little capital investment by abruptly deflecting the wet web, at relatively high consistency, into the open areas or depressions in the contour of a coarse mesh supporting fabric, preferably by pneumatic means such as one or more pulses of high pressure and/or high vacuum. Such abrupt flexing of the web causes the web to "pop" or expand, thereby increasing the caliper and internal bulk of the wet web while causing partial debonding of the weaker bonds already formed during partial drying or dewatering. This operation is sometimes referred to herein as wet-straining. The web can then be dried to preserve the increased bulk. This discovery is particularly beneficial when applied to wet-pressing processes in which a relatively large number of bonds are formed in the wet state, but it can also be applied to throughdrying processes to further improve the quality of the resulting tissue product.
The effects of wet-straining on the web can be quantified by measuring the "Debonded Void Thickness" (hereinafter described), which is the void area or space not occupied by fibers in a cross-section of the web per unit length. It is a measure of internal web bulk (as distinguished from external bulk created by simply molding the web to the contour of the fabric) and the degree of debonding which occurs within the web when subjected to wet-straining. The "Normalized Debonded Void Thickness" is the Debonded Void Thickness divided by the weight of a circular, four inch diameter sample of the web. The determination of these parameters will be hereinafter described in connection with FIGS. 8-13.
Hence, in one aspect the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) dewatering or drying the web to a consistency of 30 percent or greater; (c) transferring the web to a coarse mesh fabric; (d) deflecting the web to substantially conform the web to the contour of the coarse fabric; and (e) drying the web.
In another aspect, the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a papermaking felt; (c) pressing the web to a consistency of about 30 percent or greater; (d) transferring the web to a coarse fabric; (e) deflecting the web to substantially conform the web to the contour of the coarse fabric; (f) throughdrying the web to a consistency of from about 40 to about 90 percent while supported on the coarse fabric; (g) transferring the throughdried web to a Yankee dryer to final dry the web; and (h) creping the web.
In yet another aspect, the invention resides in a method for making a wet-pressed tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a papermaking felt; (c) pressing the wet web to a consistency of about 30 percent or greater; (d) transferring the web to a coarse fabric; (e) deflecting the web to substantially conform the web to the contour of the coarse fabric; (f) transferring the web to a transfer fabric; (g) transferring the web to the surface of a Yankee dryer and drying the web to final dryness; and (h) creping the web.
In still another aspect, the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a papermaking felt; (c) pressing the web against the surface of a Yankee dryer and transferring the web thereto; (d) partially drying the web to a consistency of from about 40 to about 70 percent; (e) transferring the partially dried web to a coarse fabric; (f) deflecting the web to substantially conform the web to the contour of the coarse fabric; (g) transferring the web to a second Yankee dryer and final drying the web; and (h) creping the web.
In a further aspect, the invention resides in a method for making a throughdried tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a throughdryer fabric and partially drying the web in a first throughdryer to a consistency of from about 28 to about 45 percent; (c) sandwiching the partially-dried web between the throughdryer fabric and a coarse fabric; (d) deflecting the web to substantially conform the web to the contour of the coarse fabric; (e) carrying the web on the throughdryer fabric over a second throughdryer to dry the web to a consistency of about 85 percent or greater; (f) transferring the throughdried web to a Yankee dryer; and (g) creping the web.
In yet a further aspect, the invention resides in a method for making a throughdried tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a throughdrying fabric; (c) carrying the web over a first throughdryer and partially drying the web to a consistency of from about 28 to about 45 percent; (d) transferring the partially dried web to a second throughdrying fabric; (e) sandwiching the partially dried web between the second throughdrying fabric and a coarse fabric; (f) deflecting the web to substantially conform the web to the contour of the coarse fabric; (g) carrying the web over a second throughdryer to dry the web to a consistency of about 85 percent or greater; (h) transferring the web to a Yankee dryer; and (i) creping the web.
In another aspect the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the web to a papermaking felt; (c) compressing the web in a pressure nip to partially dewater the web and transferring the web to a Yankee dryer; (d) partially drying the web on the Yankee dryer to a consistency of from about 40 to about 70 percent; (e) transferring the partially dried web to a coarse mesh fabric; (f) deflecting the web to substantially conform the web to the contour of the coarse fabric; and (g) throughdrying the web.
In all aspects of the invention, the web can be creped, wet or dry, one or more times if desired. Wet creping can be an advantageous means for removing the wet web from the Yankee dryer.
The nature of the coarse fabric is such that the wet web must be supported in some areas and unsupported in others in order to enable the web to flex in response to the differential air pressure or other deflection force applied to the web. Such fabrics suitable for purposes of this invention include, without limitation, those papermaking fabrics which exhibit significant open area or three dimensional surface contour or depressions sufficient to impart substantial z-directional deflection of the web. Such fabrics include single-layer, multi-layer, or composite permeable structures. Preferred fabrics have at least some of the following characteristics: (1) On the side of the molding fabric that is in contact with the wet web (the top side), the number of machine direction (MD) strands per inch (mesh) is from 10 to 200 and the number of cross-machine direction (CD) strands per inch (count) is also from 10 to 200. The strand diameter is typically smaller than 0.050 inch; (2) On the top side, the distance between the highest point of the MD knuckle and the highest point of the CD knuckle is from about 0.001 to about 0.02 or 0.03 inch. In between these two levels, there can be knuckles formed either by MD or CD strands that give the topography a 3-dimensional hill/valley appearance which is imparted to the sheet during the wet molding step; (3) On the top side, the length of the MD knuckles is equal to or longer than the length of the CD knuckles; (4) If the fabric is made in a multilayer construction, it is preferred that the bottom layer is of a finer mesh than the top layer so as to control the depth of web penetration and to maximize fiber retention; and (5) The fabric may be made to show certain geometric patterns that are pleasing to the eye, which typically repeat between every 2 to 50 warp yarns. Suitable commercially available coarse fabrics include a number of fabrics made by Asten Forming Fabrics, Inc., including without limitation Asten 934, 920, 52B, and Velostar V800.
The consistency of the wet web when the differential pressure is applied must be high enough that the web has some integrity and that a significant number of bonds have been formed within the web, yet not so high as to make the web unresponsive to the differential air pressure. At consistencies approaching complete dryness, for example, it is difficult to draw sufficient vacuum on the web because of its porosity and lack of moisture. Preferably, the consistency of the web will be from about 30 to about 80 percent, more preferably from about 40 to about 70 percent, and still more preferably from about 45 to about 60 percent. A consistency of about 50 percent is most preferred for most furnishes and fabrics.
The means for deflecting the wet web to create the increase in internal bulk can be pneumatic means, such as positive and/or negative air pressure, or mechanical means, such as a male engraved roll having protrusions which match up with the depressions or openings in the coarse fabric. Deflection of the web is preferably achieved by differential air pressure, which can be applied by drawing a vacuum from beneath the supporting coarse fabric to pull the web into the coarse fabric, or by applying positive pressure downwardly onto the web to push the web into the coarse fabric, or by a combination of vacuum and positive pressure. A vacuum suction box is a preferred vacuum source because of its common use in papermaking processes. However, air knives or air presses can also be used to supply positive pressure if vacuum cannot provide enough of a pressure differential to create the desired effect. When using a vacuum suction box, the width of the vacuum slot can be from approximately 1/16" to whatever size is desired, as long as sufficient pump capacity exists to establish sufficient vacuum. In common practice vacuum slot widths from 1/8" to 1/2" are most practical.
The magnitude of the pressure differential and the duration of the exposure of the web to the pressure differential can be optimized depending upon the composition of the furnish, the basis weight of the web, the moisture content of the web, the design of the supporting coarse fabric, and the speed of the machine. Without being held to any theory, it is believed that the sudden deflection of the web, followed by the immediate release of the pressure or vacuum, causes the web to flex down and up and thereby partially debond and hence expand. Suitable vacuum levels can be from about 10 inches of mercury to about 28 inches of mercury, preferably about 15 to about 25 inches of mercury, and most preferably about 20 inches of mercury. Such levels are higher than would ordinarily be used for mere transfer of a web from one fabric to another.
The number of times the wet web can be transferred to a coarse fabric and subjected to a pressure differential can be one, two, three, four or more times. To effect a more uniform bulking of the web, it is preferred that the wet straining vacuum be applied to both sides of the web. This can be conveniently accomplished simply by transferring the web from one fabric to another, in which the web is inherently supported on a different side after each transfer.
The method of this invention can preferably be applied to any tissue web, which includes webs for making facial tissue, bath tissue, paper towels, dinner napkins, and the like. Suitable basis weights for such tissue webs can be from about 5 to about 40 pounds per 2880 square feet. The webs can be layered or unlayered (blended). The fibers making up the web can be any fibers suitable for papermaking. For most papermaking fabrics, however, hardwood fibers are especially suitable for this process, as their relatively short length maximizes debonding rather than molding during the wet-straining operation. The wet-straining process can be used for either layered or homogeneous webs.
In carrying out the method of this invention, the change in Debonded Void Thickness of the web when subjected to the wet-straining step can be about 5 percent or greater, more preferably about 10 percent or greater, and suitably from about 15 to about 75 percent.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1A and 1B are cross-sectional photographs of a conventional wet-pressed tissue web and a tissue web processed in accordance with this invention, respectively, illustrating the increase in internal bulk resulting from the method of this invention.
FIGS. 2-7 are schematic flow diagrams of different aspects of the method of this invention referred to above.
FIGS. 8-13 pertain to the method of determining the Debonded Void Thickness of a sample.
FIG. 14 is a schematic illustration of the apparatus used to wet strain handsheets in the Examples.
FIG. 15 is a plot of the Debonded Void Thickness as a function of consistency, illustrating the data as described in Example 2.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the Drawing, the invention will be described in greater detail. Wherever possible, the same reference numerals are used in the various Figures to identify the same apparatus for consistency and simplicity. In all of the embodiments illustrated, conventional papermaking apparatus and operations can be used with respect to the headbox, forming fabrics, dewatering, transferring the web from one fabric to another, drying and creping, all of which will be readily understood by those skilled in the papermaking art. Nevertheless, these conventional aspects of the invention are illustrated for purposes of providing the context in which the various wet-straining embodiments of this invention can be used.
FIGS. 1A and 1B are 150× photomicrographs of handsheets of nominally equal basis weight. The handsheet of FIG. 1A (Sample 1A) was wet-pressed, while the handsheet of FIG. 1B (Sample 1B) was wet-pressed and thereafter wet-strained in accordance with this invention. Both handsheets were made from 50/50 blends of spruce and eucalyptus dispersed in a British Pulp Disintegrator for 5 minutes. Both sheets were then pressed between blotters in an Allis-Chalmers Valley Laboratory Equipment press for 10-15 seconds at 90-95 pounds per square inch gauge (psig) pressure. Sheet consistencies were 56±3 percent. Sample 1A was then dried while sample 1B was wet-strained as described herein and then dried. As the photos illustrate, the wet-straining reduced the density of the sheet yielding a significantly higher caliper. Sample 1A is typical of the structure of wet-pressed sheets while Sample 1B has a more debonded structure having greater internal bulk, similar to a throughdried sheet. The Debonded Void Thickness of Sheet 1A was 31.5 microns compared to 38.9 microns for Sheet 1B. Normalizing using basis weight led to Normalized Debonded Void Thickness values of 138.2 microns per gram and 169.9 microns per gram, respectively. The 23 percent increase in Normalized Debonded Void Thickness with only a 14 percent reduction in tensile strength (from 1195 grams per inch of sample width to 1029 grams) illustrates the improvement provided by wet-straining.
FIG. 2 illustrates a combination throughdried/wet-pressed method of making creped tissue in accordance with this invention. Shown is a headbox 1 which deposits an aqueous suspension of papermaking fibers onto an endless forming fabric 2 through which some of the water is drained from the fibers. The resulting wet web 3 retained on the surface of the forming fabric has a consistency of about 10 percent. The wet web is transferred to a papermaking felt 4 and further dewatered in a press nip 5 formed between felt 4 and a second felt 4. The press nip further dewaters the wet web to a consistency of about 30 percent or greater. The dewatered web 6 is then transferred to a coarse mesh throughdrying fabric 7 and wet-strained with vacuum source 8 positioned underneath the throughdrying fabric to abruptly deflect some of the fibers in the web into the open areas or depressions in the throughdrying fabric and thereby partially debond the web and increase its caliper or thickness. Also shown is an optional wet-straining station comprising a coarse mesh fabric 9 and a vacuum source 8', which can be used in addition to the other wet straining operation or as a replacement therefor. Providing two wet-straining stations provides added flexibility in the use of two different coarse mesh fabrics, which can be utilized to wet-strain the web independent of the desired throughdrying fabric. The wet-straining stations can operate on the web simultaneously or in sequence. In addition, in all of the embodiments shown herein, the wet-straining vacuum sources can be assisted by providing a high pressure air source which directs an air stream onto the opposite side of the web, thereby providing a further increase in pressure differential across the coarse fabric and increasing the driving force to deflect fibers into the coarse fabric.
The wet-strained web 10 is then carried over the throughdrying cylinder 11 and preferably dried to a consistency of from about 85 percent to about 95 percent. The dried web 12 is then transferred to an optional transfer fabric 13, which can be either fine or coarse, which is used to press the web against the surface of the Yankee dryer 14 with pressure roll 15 to adhere the web to the Yankee surface. The web is then completely dried, if further drying is necessary, and dislodged from the Yankee with a doctor blade to produce a creped tissue 16.
FIG. 3 illustrates a wet-press method of this invention in which a throughdryer is not used. Shown is a headbox 1 which deposits an aqueous suspension of papermaking fibers onto a forming fabric 2 to form a wet web having a consistency of about 10 percent. The wet web is transferred to a papermaking felt 4 and further dewatered in a press nip 5 formed between felt 4 and a second felt 4'. The dewatered web 6 is then transferred to a coarse mesh fabric 31 and wet-strained using vacuum source 8 before transferring to fabric 32. Optionally, a vacuum source 8' can be utilized in addition to vacuum source 8 or in place of vacuum source 8. If used in addition to vacuum source 8, additional wet-straining can be achieved. If the coarseness of fabric 32 is different than that of fabric 31 or if the mesh openings of the two fabrics do not coincide, areas of the web not strained by the first vacuum source can be strained by the second vacuum source. In any event, the second vacuum source acts upon the opposite side of the web to achieve additional straining and debonding of the web. Wet-straining from both sides of the web can be particularly advantageous if layered webs are present, especially if the outer layers are more susceptible to debonding than the inner layer(s). As previously mentioned, a predominance of hardwood fibers in the outer layer lends itself well to wet-straining. The wet-strained web 33 is then transferred to the surface of Yankee dryer 14 using pressure roll 15 and dislodged by doctor blade (creped), resulting in creped tissue 34.
FIG. 4 illustrates a method of this invention utilizing two dryers in series with wet-straining in between. Shown is a headbox 1 which deposits the aqueous suspension of papermaking fibers onto a forming fabric 2 to form a wet web 3 having a consistency of about 10 percent. The wet web is transferred to a papermaking felt 4 and further dewatered and pressed onto the surface of Yankee dryer 14 using pressure roll 15. The consistency of the web after transfer to the surface of the Yankee is preferably about 40 percent. (The Yankee can optionally be replaced by a throughdryer, which would require transfer of the web from the felt 4 to a throughdryer fabric or replacement of the felt with a throughdryer fabric, not shown.) The Yankee (or the throughdryer) serves to partially dry the dewatered web to a consistency of preferably from about 50 to about 70 percent. The partially-dried web is then transferred to a coarse mesh fabric 41 with the assistance of vacuum suction roll 42 and wet-strained using vacuum source 8. Optionally, the web can be sandwiched between fabric 41 and another coarse fabric 41' and further wet-strained using a second vacuum source 8'. The second vacuum source can be applied to the web simultaneously with vacuum source 8 to simultaneously act upon both sides of the web, or the second vacuum source can be applied upstream or downstream of the first vacuum source to sequentially act upon opposite sides of the web. In any event, the application of two or more vacuum straining sources is expected to provide more uniform debonding of the web. After wet-straining, the web is transferred to a Yankee dryer 14' for final drying and creped to yield a creped tissue web.
FIG. 5 illustrates another embodiment of this invention in which two throughdryers are used to dry the web. Shown is the headbox 1 which deposits the aqueous suspension of papermaking fibers onto the surface of forming fabric 2. The wet web 3 is transferred to an optional fine mesh transfer fabric 51 and thereafter transferred to a coarse mesh throughdryer fabric 7. The web is then partially dried in the first throughdryer 11 to a consistency of preferably about 45 percent. The partially dried web is then sandwiched between the throughdryer fabric 7 and coarse mesh fabric 52 and wet-strained using vacuum source 8. (For purposes herein, bringing a web into contact with a coarse mesh fabric, such as sandwiching the web against the coarse mesh fabric 52, is considered "transferring" the web to the coarse mesh fabric, even though the web continues to travel with a different fabric, such as the throughdryer fabric in this case.) Optionally, the web can be simultaneously or subsequently wet-strained from the opposite direction on the throughdryer fabric to further debond the web.
After wet-straining, the web is carried over a second throughdryer 11' and further dried to a consistency of preferably about 85 to about 95 percent, transferred to a fine mesh fabric 53, and pressed onto the surface of a Yankee dryer 14 for final drying, if necessary, and creping to produce creped web 27. In the case of final drying on the second throughdryer, transfer to the Yankee for creping is an option. It is within the scope of this invention that whenever a throughdryer is used to dry the web, the final product can be uncreped.
FIG. 6 illustrates a similar process to that of FIG. 5, but using two throughdrying fabrics. Shown is the headbox 1 depositing the aqueous suspension of papermaking fibers onto the surface of the forming fabric 2. The web 3 is transferred to optional fine mesh fabric 51 and thereafter transferred to throughdrying fabric 7. The web is carried over the first throughdryer 11 and partially dried to a consistency of preferably about 45 percent. The partially dried web is then transferred to a second throughdryer fabric 7' and sandwiched between the second throughdryer fabric and coarse fabric 61. Vacuum source 8 is used to wet-strain and partially debond the web as previously described. Optionally, the web can be wet-strained from the opposite direction using alternative vacuum source 8', either in addition to or in place of vacuum source 8. The web is then further dried in a second throughdryer 11', transferred to a Yankee 14 and creped. Optionally, the web can be wet-strained using optional vacuum sources 8" and 8"'. If vacuum source 8" is used, a coarse fabric 62 is used to provide the depressions into which the fibers in the web are deflected.
FIG. 7 illustrates another embodiment of this invention, similar to that illustrated in FIG. 4, but using a throughdryer 11 to final dry the web.
FIGS. 8-14 pertain to the method for determining the Debonded Void Thickness, which is described in detail below. Briefly, FIG. 8 illustrates a plan view of a specimen sandwich 80 consisting of three tissue specimens 81 sandwiched between two transparent tapes 82. Also shown is a razor cut 83 which is parallel to the machine direction of the specimen, and two scissors cuts 84 and 85 which are perpendicular to the machine direction cut.
FIG. 9 illustrates a metal stub which has been prepared for sputter coating. Shown is the metal stub 90, a two-sided tape 91, a short carbon rod 92, five long carbon rods 93, and four specimens 94 standing on edge.
FIG. 10 shows a typical electron cross-sectional photograph of a sputter coated tissue sheet using Polaroid® 54 film.
FIG. 11A shows a cross-sectional photograph of the same tissue sheet as shown in FIG. 10, but using Polaroid 51 film. Note the greater black and white contrast between the spaces and the fibers.
FIG. 11B is the same photograph as that of FIG. 11A, except the extraneous fiber portions not connected or in the plane of the cross-section have been blacked out in preparation for image analysis as described herein.
FIG. 12 shows two Scanning Electron Micrograph (SEM) specimen photographs 100 and 101 (approximately 1/2 scale), illustrating how the photographs are trimmed to assemble a montage in preparation for image analysis. Shown are the photo images 102 and 103, the white border or framing 104 and 105, and the cutting lines 106 and 107.
FIG. 13 shows a montage of six photographs (approximately 1/2 scale) in which the white borders of the photographs are covered by four strips of black construction paper 108.
FIG. 14 is a schematic illustration of the apparatus used to wet strain sample handsheets as described in the Examples. Shown is a sample holder 110 which contains an Asten 934 throughdrying fabric. The sample holder is designed to accept a similarly sized handsheet mold in which the handsheet sample is formed and supported by a suitable forming fabric. Also shown is a vacuum tank 111, a slideable rod 112 connected to a slideable "sled" 113 having a 1/4 inch (0.63 centimeters) wide slot 114 through which vacuum is applied to the sample, a pneumatic cylinder 115 for propelling the sled underneath the sample, and a shock absorber 116 for receiving and stopping the rod. In operation, the vacuum tank is evacuated as indicated by arrow 117 to the desired vacuum level via a suitable vacuum pump. The handsheet, while still in the handsheet mold and having one side is still in contact with the forming fabric of the handsheet mold and at the desired consistency, is placed "upside down" in the sample holder of the illustrated apparatus such that the other side of the handsheet is in contact with the throughdryer fabric of the sample holder. The pneumatic cylinder is then pressurized with nitrogen gas to cause the rod 112 and the connected sled 113 to move at a controlled speed toward the shock absorber at the end of the apparatus. In so doing, the slot in the sled briefly passes under the sample holder as shown and thereby briefly subjects the sample to the vacuum, thereby mimicking a continuous process in which the tissue is moving and the vacuum slot is fixed. The brief exposure to vacuum wet strains the sample as it is transferred to the throughdrying fabric in the sample holder. The handsheet is then dried to final dryness while supported by the throughdrying fabric by any suitable noncompressive means such as throughdrying or air drying. In all of the examples described herein, the speed of the sled was 2000 feet per minute (10.1 meters per second) and the level of vacuum was 25 inches of mercury.
DEBONDED VOID THICKNESS
The method for determining the Debonded Void Thickness (DVT) is described below in numerical stepwise sequence, referring to FIGS. 8-13 from time to time. In general, the method involves taking several representative cross-sections of a tissue sample, photographing the fiber network of the cross-sections with a scanning electron microscope (SEM), and quantifying the spaces between fibers in the plane of the cross-section by image analysis. The total area of spaces between fibers divided by the frame width is the DVT for the sample.
A. Specimen Sandwiches
1. Samples should be chosen randomly from available material. If the material is multi-ply, only a single ply is tested. Samples should be selected from the same ply position. The same surface is designated as the upper surface and samples are stacked with the same surface upwards. Samples should be kept at 30° C. and 50 percent relative humidity throughout testing.
2. Determine the machine direction of the sample, if it has one. The cross-machine direction of the sample is not tested. The cross-section will be cut such that the cut edge to be analyzed is parallel to the machine direction. For strained handsheets the cut is made perpendicular to the wire knuckle pattern.
3. Place about five inches (127 millimeters) of tape (such as 3M Scotch™ Transparent Tape 600 UPC 021200-06943), 3/4 inch (19.05 millimeters) width, on a working surface such that the adhesive side is uppermost. (The tape type should not shatter in liquid nitrogen).
4. Cut three 5/8 inch (or 15.87 millimeters) wide by about 2" (or 50.8 millimeters) long specimens from the sample such that the long dimension is parallel to the machine direction.
5. Place the specimens on the tape in an aligned stack such that the borders of the specimens are within the tape borders (see FIG. 8). Specimens which adhere to the tape will not be usable.
6. Place another length of tape of about 5 inches (or 127 millimeters) on top of the stack of specimens with the adhesive side towards the specimens and parallel to the first tape.
7. Mark on the upper surface of the tape which is the upper surface of the specimen.
8. Make twelve specimen sandwiches. One photo will be taken for each specimen.
B. Liquid Nitrogen Sample Cutting
Liquid nitrogen is used to freeze the specimens. Liquid nitrogen is dispensed into a container which holds the liquid nitrogen and allows the specimen sandwich to be cut with a razor blade while submerged. A VISE GRIP™ pliers can hold the razor blade while long tongs secure and hold the specimen sandwich. The container is a shallow rigid foam box with a metal plate in the bottom for use as a cutting surface.
1. Place the specimen sandwich in a container which has enough liquid nitrogen to cover the specimen. Also place the razor blade in the container to adjust to temperature before cutting. A new razor blade must be used for each sandwich to be cut.
2. Grip the razor blade with the pliers and align the cutting edge length with the length of the specimen such that the razor blade will make a cut that is parallel with the machine direction. The cut is made in the middle of the specimen. (See FIG. 8).
3. The razor blade must be held perpendicular to the surface of the specimen sandwich. The razor blade should be pushed downward completely through the specimen sandwich so that all layers are cleanly cut.
4. Remove the specimen sandwich from the liquid nitrogen.
C. Metal Stub Preparation
1. The metal stubs' dimensions are dictated by the parameters of the SEM. The dimensions as illustrated in FIG. 9 are about 22.75 millimeters in diameter and about 9.3 millimeters thick.
2. Label back/bottom of stub with the specimen name.
3. Place a length of two-sided tape (3M Scotch™ Double-Coated Tape, Linerless 665, 1/2 inch [or about 12.7 millimeters] wide) across the diameter of the stub. (See FIG. 9).
4. Place about a 1/4" (or about 6.35 millimeters) length of 1/8 inch (or about 3.17 millimeters) diameter carbon rod (manufacturer: Ted Pella, Inc., Redding, Calif., 1/8" [or 3.17 millimeters] diameter by 12-inch [or 304.8 millimeters] length, Cat. #61-12) at one end of the tape within the edges of the stub such that its length is perpendicular to the length of the tape. This marks the top of the stub and the upper surface of the specimen.
5. Place a longer rod below the short rod. The length of the rod should not extend beyond the edge of the stub and should be approximately the length of the specimen.
6. Cut the specimen sandwich perpendicular to the razor cut at the ends of the razor cut (see FIG. 8).
7. Remove the inner specimen and place standing up next to (and touching) the carbon rod such that its length is parallel to the rod's length and its razor cut edge is uppermost. The upper surface of the specimen should face the small carbon rod.
8. Place another carbon rod approximately the length of the specimen next to the specimen such that it is touching the specimen. Again, the rod should not extend beyond the disk edges.
9. Repeat specimen, rod, specimen, rod until the metal stub is filled with four specimens. Three stubs will be used for the procedure.
D. Sputter Coating the Specimen
1. The specimen is sputter coated with gold (Balzar's Union Model SCD 040 was used). The exact method will depend on the sputter coater used.
2. Place the sample mounted on the stub in the center of the sputter coater such that the height of the sample edge is about in the middle of the vacuum chamber, which is about 11/4 inches (or 31.75 millimeters) from the metal disk.
3. The vacuum chamber arm is lowered.
4. Turn the water on.
5. Open the argon cylinder valve.
6. Turn the sputter coater on.
7. Press the SPUTTERING button twice. Set the time using SET and FAST buttons. Three minutes will allow the specimen to be coated without over-coating (which could cause a false thickness) or under coating (which could cause flaring).
8. Press the STOP button once so it is flashing. Press the TENSION button at this time. The reading should be 15-20 volts. Hold the TENSION button down and press CURRENT UP and hold. After about a ten-second delay, the reading will increase. Set to approximately 170-190 volts. The current will not increase unless the STOP button is flashing.
9. Release the TENSION and CURRENT UP buttons as you turn the switch on the arm to the green dot to open the window. The current should read about 30 to 40 milliamps.
10. Press the START button.
11. When completed, close the window on the arm and turn the unit off. Turn off the water and argon. Allow the unit to vent before the specimen is removed.
E. Photographing with the SEM
(JEOL, JSM 840 II, distributed by Japanese Electro Optical Laboratories, Inc. located in Boston, Mass.). A clear, sharp image is needed. Several variables known to those skilled in the art of microscopy must be properly adjusted to produce such an image. These variables include voltage, probe current, F-stop, working distance, magnification, focus and BSE Image wave form. The BSE wave form must be adjusted up to and slightly beyond the reference limit lines in order to obtain proper black-&-white contrast in the image.
These variables are adjusted to their optimum to produce the clear, sharp image necessary and individual adjustments are dependent upon the particular SEM being used. The SEM should have a thermatic source (tungsten or Lab 6) which allows large beam current and stable emission. SEMs which use field emission or which do not have a solid state back scatter detector are not suitable.
1. Load the stub such that the specimen's length is perpendicular to the tilt direction and lowered as far as possible into the holder so that the edge is just above the holder. Scan rotation may be necessary depending on the SEM used.
2. Adjust the working distance (39 millimeters was used). The specimen should fill about 1/3 of the photo area, not including the mask area. (For handsheets, a magnification of 150× was used.)
3. Use the tilt angle of the SEM unit to show the very edge of the specimen with as little background fibers as possible. Do not select areas that have long fibers that extend past the frame of the photo.
4. One photomicrograph is taken using normal film (POLAROID 54) for gray levels for comparison. The F-stop may vary. The areas selected should be representative and not include long fibers that extend beyond the vertical edge of the viewing field.
5. Without moving the view, take one photomicrograph using back scatter electrons with high contrast film (51 Polaroid). The F-stop may vary. A sharp, clear image is needed. After the photomicrographs are developed, a black permanent marker is used to black out background fibers that are out of focus and are not on the edge of the specimen. These can be selected by comparing the photomicrograph to the gray level photomicrograph of Step 4 above. (See FIGS. 10 and 11.)
6. A total of twelve photomicrographs are taken to represent different areas of the specimens; one photomicrograph is taken of each specimen.
7. A protective coating is applied to the photo on 51 film.
F. Image Analysis of SEM Photos
1. The 12 photos are arranged into two montages. Six photos are used in each montage. Make two stacks of six photos each, and cut the white framing off the left side of one and the white framing off the right side of the remaining stack without disturbing the photos. (See FIG. 12.)
2. Then, taking one photo from each stack, place cut edges together and tape together with the tape on the back of the photo (3M Highland™ Tape, 3/4 inch [or 19.05 millimeters]). No extraneous white of the background should show at the cut, butted edges.
3. Arrange the photos with a small overlap from top to bottom as in FIG. 13.
4. Turn on the image analyzer (Quantimet 970, Cambridge Instruments, Deerfield, Ill.). Use a 50 mm. El-Nikkor lens with C-mount adaptor (Nikon, Garden City, N.Y.) on the camera and a working distance of about 12 inches (305 millimeters). The working distance will vary to obtain a sharp clear image on the monitor and the photo. Make sure the printer is on line.
5. Load the program (described below).
6. Calibrate the system for the photo magnification (which will generate the calibration values indicated by "x.xxxx" in the program listed below), set shading correction with white photo surface (undeveloped x-ray film), and initialize stage (12 inches by 12 inches open frame motor-driven stage (auto stage by Design Components, Inc., Franklin, Mass.)) with step size of 25 microns per step.
7. Load one of the two photo montages under a glass plate supported on the stage after strips of black construction paper are placed over the white edges of the photos. The strips are 3/4 inch wide (18.9 millimeter) and 11 inches long (279 millimeters) and are placed as in FIG. 13 so that they do not cover the image in the photo. The montage is illuminated with four 150 watt, 120 volt GE reflector flood lamps positioned with two lamps positioned at an angle of about 30' on each side of the montage at a distance of about 21 inches (533 millimeters) from the focus point on the montage.
8. Adjust the white level to 1.0 and the sensitivity to about 3.0 (between 2 and 4) for the scanner using a variable voltage transformer on the flood lamps.
9. Run the program. The program selects twelve fields of view: two per photomicrograph.
10. Repeat at the pause with the second montage after completion of twelve fields of view on the first montage.
11. A printout will give the Debonded Void Thickness.
G. Computer Program.
______________________________________Enter specimen identityScanner (No. 2 Chaincon LV = 0.00 SENS = 1.64 PAUSE)Load Shading Corrector (pattern - OFOSU3)Calibrate User Specified(Calibration Value = x.xxxx microns per pixel)(PAUSE)CALL STANDARDTOTDEBARE : = 0.For SAMPLE = 1 to 2Stage Scan ( X Y scan origin 10000.0 10000.0 filed size 16500.0 11000.0 no. of fields 3 4 )Detect 2D (Lighter than 32 PAUSE)For FIELDScanner (No. 2 Chaincon AUTO-SENSITIVITY LV = 0.00)Live Frame is Standard Live FrameDetect 2D (Lighter than 32)Amend (OPEN by 1)Measure filed - Parameters into array FIELDRAWAREA: = FIELD AREAAmend (CLOSE by 20)Image Transfer from Binary B (FILL HOLES) to Binary OutputMeasure field - Parameters into array FIELDFILLAREA: = FIELD AREADEBNAREA: = FILLAREA - RAWAREATOTDEBARE: = TOTDEBARE + DEBNAREAStage StepNext FIELDPauseNextFIELDNUM: = FIELDNUM * (SAMPLE - 1.)Print " "Print "DEBOND VOID THICKNESS =",( TOTDEBARE / FIELDNUM)/(625.* CAL.CONST )Print " "For LOOPCOUNT = 1 to 7Print " "NextEnd of Program______________________________________
EXAMPLES
In order to further illustrate the invention, a number of handsheets were prepared as follows:
The pulp was dispersed for five minutes in a British pulp disintegrator. Circular handsheets of four-inch diameter, conforming precisely to the dimensions of the sample holder used for wet-straining, were produced by standard techniques. The sample holder contained a 94-mesh forming fabric on which the handsheets were formed. After formation the handsheets were at about 5 percent consistency. For those samples not wet-pressed (Example 1), the samples were dried to the consistency selected for wet-straining by means of a hot lamp and then wet-strained. For those experiments involving pressing (Example 2), the handsheet was removed from the sample holder by couching with a dry blotter. The sheet was then pressed in an Allis-Chalmers Valley Laboratory Equipment press. Pressing time and/or pressure were varied to achieve the desired post-pressing consistency. Selected samples were then wet-strained.
Wet-straining of the handsheets was performed using the apparatus previously described in reference to FIG. 14. In all cases, a sample holder containing an Asten 934 throughdrying fabric was placed in the wet-straining apparatus. When the base sheet reached the desired consistency, either by pressing or drying with the lamp, the holder on which the sheet was formed was placed "upside down" in the straining apparatus such that the surface of the sheet not in contact with the forming fabric came in contact with the surface of the throughdrying fabric. A sled was then caused to slide underneath the sample holders exposing the sheet to vacuum, causing the sheet to be wet-strained and transferred to the throughdrying fabric. In all cases, a sled speed of 2000 fpm and a vacuum of 25 inches of mercury were utilized. The sheet, now located on the throughdrying fabric, was then dried to complete dryness in a noncompressive manner.
EXAMPLE 1
Handsheets were made from a 100 percent eucalyptus furnish and dried with a hot lamp to various consistencies prior to wet-straining as described above. After wet-straining, various physical parameters were measured as shown in TABLE 1 below. (Sample weight is expressed in grams; Consistency is expressed in weight percent; Tensile strength is expressed as grams per inch of sample width; Normalized tensile strength is the tensile strength divided by the sample weight, expressed as reciprocal inches; Debonded Void Thickness is expressed as microns; and Normalized Debonded Void Thickness is the Debonded Void Thickness divided by the sample weight, expressed as microns per gram.)
TABLE 1______________________________________ De- bonded Normalized Consistency Void DebondedSample Prior to Normalized Thick- VoidWeight Wet Straining Tensile Tensile ness Thickness______________________________________0.305 13.2 420 1377 86.1 282.30.235 33.6 396 1685 84.1 357.90.227 46.3 255 1123 82.6 363.9______________________________________
For comparison, an air-dried control sample (not wet-strained) weighing 0.238 grams had a tensile strength of 460 grams, a normalized tensile of 1933, a Debonded Void Thickness of 73 microns, and a Normalized Debonded Void Thickness of 306.7 microns per gram.
These results clearly show that wet-straining can be used to increase the void area relative to the weight of the sheet. As the data indicates, conducting the wet-straining at only 13 percent consistency (below the level claimed in this application) did not result in a significant increase in Normalized Debonded Void Thickness. Instead the sheet was primarily molded to the shape of the fabric. However, for the samples wet-strained at higher consistency, a definite increase in the Normalized Debonded Void Thickness was apparent and the tensile strength (a measure of bonding in the sheet) significantly decreased. Hence wet straining becomes effective at approximately 30 percent consistency or greater, with an optimum wet-straining consistency varying with furnish, fabric, etc. However, the optimum consistency is believed to lie in the 40-50 percent range.
EXAMPLE 2
Handsheets nominally weighing 0.235±0.200 grams were made From a 50/50 blend by weight of eucalyptus and spruce fibers. One set of handsheets was pressed to various consistencies (not wet strained) to serve as a control. Another set was pressed to approximately 50 percent consistency and then wet strained as described above. Consistencies, sample weights and the Debonded Void Areas were measured for each sample. The data is tabulated in TABLE 2 below and further illustrated in FIG. 15. The first six samples listed represent the control samples. The last five samples are the wet-strained samples.
TABLE 2______________________________________ De- Post bonded Normalized Pressing Void DebondedSample Consis- Normalized Thick- VoidWeight tency Tensile Tensile ness Thickness______________________________________0.252 30.7 662 2627 73.2 290.50.224 31 760 3393 56.5 252.20.237 34.9 684 2886 72.6 306.30.241 35 761 3158 59.1 245.20.228 58.5 1195 5241 31.5 138.20.229 60.3 1207 5271 29 126.60.224 51.3 774 3455 58.6 261.60.246 51.5 887 3606 64.2 2610.23 52.6 848 3687 63.1 274.30.229 54.3 1029 4493 38.9 169.90.241 58.9 826 3427 55.2 229AVER- 53.72 239.2AGE______________________________________
As shown in FIG. 15, the line in this figure is a regression line for the control data according to the equation:
Normalized Debonded Void Thickness=444.5-(5.22×Consistency).
As expected, the Normalized Debonded Void Thickness linearly decreased with pressing. While pressing is an effective means for removing water, it causes densification that reduces the Normalized Debonded Void Thickness and makes the resulting sheet less bulky and absorbent.
Also shown in FIG. 15 are the data points for the five wet straining samples and the arithmetic average for the five samples. The average Normalized Debonded Void Thickness of 239.2 at an average consistency of 53.7 percent was 46 percent higher than the predicted value of 163.8 at 53.7 percent consistency from the regression equation. This increase in Normalized Debonded Void Thickness is the desired result of the wet straining operation.
Hence it is clear that wet straining can be used to significantly increase the Debonded Void Thickness of paper. The benefits of this process can be manifested as higher Debonded Void Thickness at a given level of pressing or as the ability to press to a higher consistency while maintaining a given level of Debonded Void Thickness. Which approach is best depends on the amount of bulk and absorbency desired for a given product and the limitations of the particular papermaking process being utilized. In either case, an improved product can be produced via wet straining in accordance with this invention.
It will be appreciated that the foregoing examples, given for purposes of illustration, are not to be construed as limiting the scope of this invention, which is defined by the following claims and all equivalents thereto.
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The internal bulk of a tissue web can be improved during manufacturing of the basesheet by subjecting the tissue web to differential pressure while supported on a coarse fabric at a consistency of about 30 percent or greater. The differential pressure, such as by applying vacuum suction to the underside of the coarse fabric, causes the wet web to deflect into the openings or depressions in the fabric and "pop" back, resulting in a substantial gain in thickness or internal bulk. The method is especially adapted to improve the internal bulk of throughdried tissue webs.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to actuator buttons for aerosol containers. More specifically, the invention relates to aerosol actuators containing mechanical break-up means for atomizing the aerosol product to a high degree.
2. Description of the Prior Art
The prior art is replete with examples of so-called mechanical break-up buttons for aerosol containers. These buttons normally comprise a cylindrical body having an inlet at the bottom adapted to fit over the aerosol valve stem. At the side of the cylindrical body is a discharge orifice connected with the inlet by passage means inside the body.
Often, to comprise the discharge the body of the actuator is formed with a cylindrical recess which receives a plastic cup-shaped insert open-end first and that insert has the discharge opening in its outer or closed end. Structure has been provided to see that the product (that is, the aerosol liquid) undergoes some kind of a swirl action as it passes through the cavity formed within the insert. Examples of such structure are shown, for instance, in the U.S. Pat. No. 3,174,692, issued Mar. 23, 1965 to E. H. Green. Usually in such structure, the swirl of the product is effected in a recess on the end of a plug comprising part of the actuator body and which is disposed inside the insert. Further examples are: U.S. Pat. No. 3,129,893, issued Apr. 21, 1964 to Green; U.S. Pat. No. 3,146,737, issued Dec. 17, 1968 to Venus; U.S. Pat. No. 3,519,210, issued May 7, 1970 to Duplain; U.S. Pat. No. 3,785,571, issued Jan. 15, 1974 to Hoening; U.S. Pat. No. 3,994,442, issued Nov. 3, 1976 to Hoening; and U.S. Pat. No. 4,036,439, issued July 19, 1977 to Green. Clearly, the tangential imprint can just as well be formed on the inside of the end wall of the insert to effect the same purpose, that is, a central swirl in the insert chamber. Often, the recess has taken the form of a kind of cross or "swastika" having tangential arms. The swirl is preferably effected immediately prior to passage through the discharge orifice. It can be imagined that this swirl effects high shear and relative movement of the product particles so that there is mix break-up and atomization.
SUMMARY OF THE INVENTION
Under the present invention, a swirl is produced in the chamber within the insert by a special vane plate. This plate is sandwiched between the insert and an annular shelf formed at the inner end of the recess for the cup-shaped insert. The vane plate of the invention comprises a body having a product-deflecting vane, the vane being disposed in canted relationship to a radial plane through the valve body and adapted to direct to the side of the axis of the chamber to produce a rotary or swirled effect of the product. In devices of the invention, the width of the chamber is substantial--far greater than the swirl chamber previously molded into the top of the actuator button post. As this swirling product from this chamber is forced subsequently through the discharge orifice, it is forced to reduce in size and in accordance with the law of conservation of momentum, the particles adjacent the periphery of the swirl chamber greatly speed up the swirling action as the product moves through the narrower discharge orifice with resultant high atomization of the product outside the orifice.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and features of the invention will be apparent from the following specification and drawings, all of which disclose a non-limiting form of the invention. In the drawings:
FIG. 1 is a sectional view of an actuator button embodying the invention;
FIG. 2 is a perspective view greatly enlarged, of a vane plate in accordance with the invention;
FIG. 3 is a perspective view of a modified vane plate;
FIG. 4 is a perspective view of a further modification;
FIG. 5 is a top plan view of the FIG. 4 modification;
FIG. 6 is a sectional view comparable to FIG. 1 but showing the modified form of vane plate comprising a plastic molded body;
FIG. 7 is a greatly enlarged perspective view of the vane plate of FIG. 6;
FIG. 8 is an exploded perspective view, greatly enlarged, of the arrangement of FIG. 6;
FIG. 9 is a perspective view of a further embodiment;
FIG. 10 is a top plan view of the FIG. 9 embodiment;
FIG. 11 is a sectional view taken on the line 11--11 of FIG. 10;
FIG. 12 is a sectional view taken on the line 12--12 of FIG. 10; and
FIG. 13 is a sectional view taken on the line 13--13 of FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An aerosol container, partially shown in FIG. 1 is generally designated C. It includes at its upper end a valve pedestal P with an upstanding central stem S. The actuator button embodying the invention is generally designated 10 in FIG. 1. It comprises a generally cylindrical plastic body 12 having at its lower end an inlet sleeve 14 which is adapted to be snugly received onto the stem S. The button actuator orifice is connected through passage means to be described to the inlet sleeve 14 and the orifice is generally designated 16.
As shown, the button is formed in its front side with a generally cylindrical insert recess 18. The recess is reduced to form a well 19 surrounded by an annular shelf 22.
A disc-like vane plate 24 is disposed in the insert recess 18 and bottoms against annular shelf 22. It is held in position by the open end of a cup-shaped insert 20 which may be of molded plastic and contain an annular spur 20a which engages the wall of the insert recess to hold the insert in position. The front wall of the insert 20 is formed with an interior bevel 26 and thereby defines a cylindrical cavity 28 having bevelled edges 26 adjacent the discharge orifice 16.
Various forms of the vane plate 24 will now be described. As shown in FIG. 2, the vane plate 24 may be a stamping or the like having a single opening 30 formed at the end of a vane 32 shaped in the disc. The opening 30 is disposed on one side of the axis 34 of the disc and it can be seen that when the vane plate 24 is in position against the shelf 22 and product is moved through the opening 30, the vane and the shape of the chamber will impart to said incoming product a swirling or rotary action defined by the periphery of the interior of the insert 18. As the material in the cavity 28 moves up the bevel 26 and out the orifice 16, it will rotate with greater angular velocity in accordance with the law of conservation of angular momentum.
The FIG. 3 version of the vane plate 24' includes a pair of openings 30' and the inclined vanes 32'. The vanes and shape of the chamber 28 impart a rotary motion to the product.
In the FIG. 4 version, the vanes 32" are flaps punched out of the disc 24" and arranged so that material that has passed through the opening 30" of the disc will be imparted an annular movement in the chamber 28'. It will be seen that the general effect of the flaps 32" and the shape of the cavity is to create a swirl (see arrow) in the swirl chamber 28.
Turning now to FIG. 6, it will be seen that the construction is basically the same. The actuator button 10' is formed with a cylindrical body 12' and the sleeve 14' fits over the stem S snugly. The insert 20' is formed with a discharge orifice 16' and the recess 18' into which the insert fits is formed with an annular shelf 22'. A plastic vane plate 24"' is inserted against shelf 22' as shown in FIGS. 6 and 7 and is entrapped by the rim of the open end of the insert 20'.
The body 24"' may comprise an integral plastic ring 25 having a pair of semi-circular vanes 32"' touching in the center C of the vane plate 24"' but canted oppositely with respect to the radial plane through the center to leave openings 30"'. This effects, as best understood from FIG. 7, a rotary motion of the product in the chamber 28'. This rotary motion is speeded up as the mixture proceeds up the bevel 26' to discharge outlet 16'.
A further modification of a vane disc as contemplated by the invention is disclosed in FIGS. 9 through 13. This modification comprises a disc 24"" preferably stamped of metal such as brass and having a pair of apertures 30"" therein. As shown best in FIG. 9, these apertures are formed in the disc adjacent vane-like impressions 32"" which are disposed on opposite sides of the center C of the disc. It will be noted from FIGS. 9 and 10 that each of the openings 30"" face in a generally perpendicular direction to the plane of the disc 24"" and are formed at each of upward and downwardly deflected vanes. The vanes 32"" cooperate to direct the flow of product through the opening 30"" in a more or less tangential direction with respect to the disc 24"" so that the result is a swirl-type action inside the cavity 28 within the insert 20 (FIG. 1) when the disc of FIGS. 9 through 13 is used in such an arrangement.
Moreover, the outer margin of the vanes of the disc 24"" as shown in FIG. 10 are arcuate to even further assist in the formation of a swirl-type action.
Thus, it will be seen that the invention is susceptible of many changes, some of which are described herein. It should be understood, therefore, that the invention claimed is to be defined only by the following claim language and equivalents thereof.
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Actuator button is provided with a vane plate for deflecting the product coming into swirl chamber within the actuator button insert. This eliminates the need for a central post and molded swirl chamber formed on the post or insert as required by the prior art.
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FIELD OF THE INVENTION
The present invention is directed generally to a unit dose package. More particularly, the present invention is directed to a unit dose package for a reconstitutable powder. Most specifically, the present invention is directed to a unit dose package for a reconstitutable nutritional infant or adult formula powder form. A unit dose container carries a pre-measured amount of the nutritional formula The container has a plastic fitment which is provided with a mouth opening and with an annular threaded recess. The threaded recess is sized to cooperate with a threaded neck of a graduated bottle that contains a measured amount of a reconstituting liquid. In use, an overcap and a foil seal are removed from the unit dose package's fitment. Once this has been done, the dose package and graduated bottle are secured together and the contents of the unit dose package reconstituted by being mixed with the liquid in the graduated bottle. When secured together, the dose package and graduated bottle allow ample capacity to complete mixing of the powder and liquid because of the extra head space provided by the dose package.
DESCRIPTION OF THE PRIOR ART
Various infant and adult nutritional formulas are generally well known in the art. These typically take the form of powders or concentrated liquids which must be reconstituted or suitably diluted prior to usage. Particularly when using powdered nutritional formulas, a measured amount of the powder must be combined and then mixed with a corresponding volume of a reconstituting liquid prior to use.
Powdered nutritional formulas are frequently packaged in a bulk container which may be supplied to the user with a measuring scoop or spoon of some type. The user is then required to remove the appropriate dry measure of the powdered formula from the bulk container and to add this powdered formula to a volume of reconstituting liquid, typically water, in a baby bottle or mixing container. This procedure is apt to be less than ideal for several reasons. In the process of removing powdered formula from a bulk container with a scoop and transferring this powder to the liquid container, there is a significant opportunity to spill some of the formula. Such spillage obviously creates a mess which must be cleaned up. More importantly, such spillage is apt to adversely affect the accuracy of the reconstituted formula.
An associated problem with manual mixing of a powdered or concentrated nutritional formula with a reconstituting liquid is one of incorrect formula strength caused by inaccurate formula measurement. When a group of people were asked to prepare a formula using a certain number of scoops of powdered formula, a wide range of product concentrations was observed. People often have a difficult time properly measuring the proper amount of the powdered nutritional formula and properly mixing it with the reconstituting liquid.
Another problem is obtaining thorough mixing of powdered formula because of the lack of head space when the nursing bottle containing the reconstituting liquid is full. The unit dose package of the instant invention provides extra head space when secured to the nursing bottle thereby permitting complete mixing.
When using a bulk container of a powdered infant or adult nutritional formula, there is clearly the possibility that the bulk container, once it has been opened, may become contaminated. In a home environment, such possible contamination will typically be accidental, while in a hospital or similar setting it may not be. The hospital is apt to be quite reluctant to expose itself to the potential liability which usage of a bulk powdered nutritional formula may mean. Thus, a more costly alternative may be selected in order to avoid any potential risk of contamination.
Measuring a mixing of a reconstitutable powdered nutritional formula is apt to be more time consuming than some parents are willing to spend. Similarly, hospital nurseries and other institutional users of powdered nutritional formulas cannot afford to spend a great deal of time measuring and mixing the particular formulas required by the various babies or persons being cared for. Thus, the conventional arrangement of a bulk powdered reconstitutable nutritional formula is unacceptable to these users.
The use of powdered infant and adult nutritional formulas which must be reconstituted by mixing a measured portion of the formula with liquid has, as discussed above, various disadvantages. The mixing process is apt to be messy and may take more time than many parents and virtually all hospital nurseries are willing to take. It is also often difficult to obtain an accurate measure of the powder. Bulk containers of formula are also possible targets of product contamination or adulteration. Thus, it will be clear that a need exists for a unit dose package which will overcome these drawbacks of the prior art devices. The unit dose package, in accordance with the present invention, provides such a package and represents a significant advance in the art.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a unit dose package.
Another object of the present invention is to provide a unit dose package for mixing and dispensing liquid and powdered nutritional formulas.
A further object of the invention is to provide a unit dose package which is usable with a bottle to form a mixing container.
Yet another object of the present invention is to provide a unit dose package which is hermetically sealed and tamper resistant.
Still a further object of the present invention is to provide a unit dose package that facilitates formula reconstitution without mess or error.
Even yet another object of the present invention is to provide a unit dose package that provides the user with an accurate amount of formula for reconstitution.
Still even a further object of the present invention is to provide a unit dose package which is quick and easy to use.
Still another object of the present invention is to provide a unit dose package that provides additional head space for complete mixing of powder and reconstituting liquid.
As will be discussed in greater detail in the description of the preferred embodiment which is set forth subsequently, the unit dose package in accordance with the present invention includes a unit dose container which has a closed bottom and a plastic fitment having a mouth which is bounded by a threaded recess. The threaded recess is sized to be cooperative (compatible) with the neck of a plastic bottle. This plastic fitment is sealed by a foil closure seal and which, in turn is covered by an overlying protective overcap.
The unit dose package is supplied to the user with a measured amount of a nutritional formula, typically a powder. An appropriate amount of reconstituting liquid, such as water, is placed in a graduated plastic nurser bottle and the overcap and foil membrane seal are removed from the plastic fitment of the unit dose package. The neck of the bottle is screwed into the recess in the plastic fitment, as the unit dose package is inverted. The contents of the unit dose package are thus added to the reconstituting liquid. The combined unit dose package and plastic bottle provide a closed system with sufficient space to insure that the nutritional formula can be easily and thoroughly mixed with the reconstituting liquid by shaking the closed system.
In marked contrast to the prior art approaches which required removal of an amount of powder from a bulk container and addition of this powder to the liquid, the unit dose package of the present invention eliminates the spillage, mess, and possible inaccuracies which accompanied the prior art. Each unit dose container is supplied to the user with an appropriate quantity of nutritional formula which has been pre-measured during packaging. The formula is added to the reconstituting liquid once the unit does package and plastic nursing bottle have been cooperatively joined together. Thus, all of the formula is mixed with the liquid and the correct amount of formula is utilized.
Each unit dose package is intended to be used only once. Further, various formula strengths and compositions can be provided in appropriately labeled containers. Since each package is a unit dose, no time is wasted in measuring and mixing. The proper unit dose package is selected, opened, combined with a bottle, and mixed for use. This convenience and time saving aspect of the present invention makes it particularly attractive for busy parents and even more attractive to hospital nurseries and similar facilities.
The unit dose package is a hermetically sealed package which may be filled and sealed under a nitrogen or similar inert atmosphere to provide a product with a long shelf life. The plastic overcap protects the metal foil membrane seal which itself provides excellent tamper evidence. When this foil seal is removed, it will take with it a portion of the container itself. Thus, if the container is washed for reuse, it will be apt to start to decompose. Thus, it is a disposable package which has been structured to prevent reuse.
The unit dose package in accordance with the present invention provides a package through which a reconstitutable nutritional formula can be accurately, efficiently, and effectively mixed with a reconstituting liquid for use. It eliminates formula spillage and inaccurate measurements. At the same time, it reduces the time required to prepare and mix the formula while also minimizing the possibility of product contamination. Also, it allows sufficient head space to thoroughly mix the nutritional powder and reconstituting liquid. The unit dose package of the present invention is clearly superior to prior art devices and performs its desired functions in an expeditious manner.
BRIEF DESCRIPTION OF THE DRAWINGS
While the novel features of the unit dose package in accordance with the present invention are set forth with particularity in the appended claims, a full and complete understanding of the invention may be had by referring to the detailed description of the preferred embodiment which is presented subsequently, and as illustrated in the accompanying drawings, in which:
FIG. 1 is an exploded perspective view of the unit dose package of the present invention.
FIG. 2 is a perspective view of a graduated nursing bottle usable with the unit dose package of FIG. 1;
FIG. 3 is an elevation view, partly in section and showing the unit dose package and bottle in their assembled, mixing position; and
FIG. 4 is an exploded perspective view of the unit dose package and bottle complimentarily positioned.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIG. 1 there may be seen, generally at 10, a unit dose package in accordance with the present invention. As will be discussed in greater detail shortly, unit dose package 10 is usable with a cooperating bottle, typically a plastic graduated nursing bottle, generally at 12 in FIG. 2. Unit dose package 10 and bottle 12 are securable together in a manner as is shown in FIG. 3 to provide a closed system for mixing and reconstitution of the contents of the unit dose package with a reconstituting liquid which is in bottle 12. After such mixing and reconstitution, the now empty unit dose package 10 may be separated from bottle 12, as shown in FIG. 4 and the contents of bottle 12 may now be used in a generally conventional and well known manner. While unit dose package 10 will be discussed hereinafter as containing a powdered nutritional formulation, such as powdered baby formula, and further while bottle 12 will be discussed as being a plastic graduated nursing bottle in which the reconstituting liquid is water, it will be understood that this is for ease of explanation and that the contents of unit dose package 10 are not to be construed as being so limited and that the bottle and its reconstituting liquid also are not so limited.
Returning again to FIG. 1, unit dose package 10 includes a generally cylindrical body 14, a metal container bottom 16 secured to the bottom of the cylindrical body 14, a plastic fitment 18 secured to an upper portion of cylindrical body 14, a foil seal membrane 20 which is removably sealed to plastic fitment 18, and a protective overcap 22 that overlies and protects metal foil membrane 20. This unit dose package 10 is ideally structured for fillage on a high speed packaging line with a dry infant or adult nutritional formula and when filled and closed, forms a hermetically sealed package in which the powdered formula may be sealed under a nitrogen atmosphere to give the product a long shelf life.
Cylindrical body 14 of unit dose package 10, as may be seen in FIGS. 1 and 4, is a composite which preferably includes an inner liner 24 of a foil and polypropylene coated kraft paper, and one or more outer body plies 26 which may be of a suitable kraft paper. Outer surface 28 of cylindrical body 14 may be a suitable print receiving paper or aluminum foil which may be treated, after printing, with a generally well known lacquer. Metal package bottom 16 is provided with an outer peripheral flange 30 which may define an appropriately dimensioned channel (not shown) into which a bottom edge 32 of cylindrical body 14 may be sealingly secured. As will be understood by those in the art, this bottom 16 is typically attached to cylindrical body 14 after the contents have been placed inside unit dose package 10. The bottom end 16 is scamed onto bottom edge 32 of cylindrical body 14 with automatic can end scaming equipment.
As may be seen most clearly in FIG. 3, the upper portion of inner liner 26 of cylindrical body 14 terminates in a radially outwardly and downwardly extending curl 34. This curl rolls over an upper edge 36 of the outer body plies 26. Curl 34 provides a surface to which the foil seal membrane 20 may be bonded. Membrane 20, as may be seen most clearly in FIG. 1, overlies plastic fitment 18 and curl 34. The foil membrane 20 is preferably formed of a foil with a hot melt adhesive that can be bonded by suitable R.F. sealing means or other heat means to the top of fitment 18 and to the foil and polypropylene on curl 34. When foil membrane seal 20 is removed, such as by grasping the integral pull tab 38, a portion of the foil and polypropylene on curl 34 will also be removed. This will expose a portion of the paper portion of liner 24. Thus, if an attempt is made to wash unit dose package 10 after it has been opened, it will start to decompose. This will discourage reuse of package 10.
Turning now to FIGS. 3 and 4, plastic fitment 18 will be seen as being situated within cylindrical body 14 of unit dose package 10 generally adjacent an upper portion 40 of body 14 when the unit dose package 10 is in the upright position depicted in FIG. 1. Plastic fitment 18 includes a central open mouth 42 which is defined by an annular mouth ring 44. A transverse web 46 extends radially outwardly from a bottom portion 48 of mouth ring 44. An attachment ring 50, which is generally concentric with mouth ring 44, is formed integrally with, and extends generally perpendicular to transverse web 46 of plastic fitment 18. Attachment ring 50 has an upper rim 52 which is situated adjacent curl 34 when plastic fitment 18 is slid into the upper portion 40 of cylindrical body 14 of unit dose package 10. An outer peripheral surface 54 of attachment ring 50 is coextensive with an upper inner surface 56 of inner linear 24 of cylindrical body 14. Surface 54 of attachment ring 50 of plastic fitment 18 and inner surface 56 of inner liner 24 are bonded together by suitable R.F. heating or other similar heating. This bonding is strong enough to resist any rotational torque which might be applied to plastic fitment 18 when it is secured to, or removed from bottle 12, as will be discussed subsequently. The bonding also provides a water tight seal that does not leak when the powder and liquid are mixed together.
A threaded ring 60 is also formed as a segment of plastic fitment 18. As may best be seen in FIG. 3, threaded ring 60 is concentric with, and spaced between inner mouth ring 17 and outer attachment ring 50. Threaded ring 60 is joined at a lower portion 62 to transverse web 46 and terminates in an upper rim 64 which is generally co-planar with upper rim 52 of attachment ring 50 and an upper rim 66 of mouth ring 44. A helical screw thread 68 is molded on the radially inner surface 70 of threaded ring 60. This thread 68 is sized to cooperate with the generally conventional helical screw thread 72 that is found on the outer neck surface 74 of a neck portion 76 of bottle 12. An inner, bottle neck receiving channel 80 is defined by mouth ring 44, threaded ring 60 and their connecting portion of transverse web 46. A spacing channel 82 is defined between threaded ring 60, outer attachment ring 50 and their connection portion of transverse web 46.
An optional feature of the invention not shown by the drawings comprises a water soluble membrane covering open mouth 42 of plastic fitment 18 or spaced within the annular mouth ring 44 to contain the contents of the unit dose package. Preferably, the water soluble membrane is formed of rice paper but other water soluble membranes of carbohydrate based material such as corn starch, potato starch, wheat starch, tapioca starch, etc. can be used. The membrane is attached to lower ring 65 or secured within the annular mouth ring 44 by suitable R.F. sealing means. The membrane insures that no spillage of the nutritional powder formula will occur when unit dose package 10 is turned into the inverted position shown in FIG. 3. Upon shaking the assembly, the water soluble membrane dissolves and mixing of the contents of unit dose package 10 and bottle 12 can be accomplished.
As previously alluded to, bottle 12 is preferably a graduated nursing bottle that is molded from a suitable plastic in a generally conventional configuration. Bottle 12 has a bottom 90, a generally cylindrical sidewall 92 which may have a reduced diameter central region 94 to facilitate grasping, and a plurality of graduation marks 96 which may include an upper maximum fill line. Bottle 12 has an open mouth 98 which is defined by bottle neck 76. This neck 76 terminates in an upper neck rim 100, all in a generally conventional manner. As may be seen in FIG. 3, the surface of bottle neck rim 100 will abut the upper surface of transverse web 46 of plastic fitment 46 when unit dose package 10 is crewed onto the neck 76 of bottle 12.
Empty unit dose packages 10 which have been provided by the fabricator with metal bottoms 16 not attached, are given a highly accurate filling of a powdered reconstitutable infant or adult nutritional formula on a high speed packaging line. Once the formula has been placed in the package, the metal bottom is attached by normal can end scaming equipoment. The unit dose package 10 can now be shipped and stored until usage. When the user is ready to reconstitute and mix the formula, he first adds the appropriate volume of reconstituting liquid to bottle 12 using graduations 96 as a guide. He then may remove protective overcap 22 by grasping a rim portion 102 thereof. This overcap 22 is preferably fabricated of a thin polystyrene material and snap fits over the upper end of a unit dose package 10. Once overcap 22 has been removed, the user can visually inspect foil membrane 20 to insure that it has not been tampered with. Having done this, the user may then remove foil membrane 20 by grasping the pull tab 38 and pulling upwardly on it. This force will separate the foil membrane seal 20 from the upper rims 52, 64 and 66 of the plastic fitment, and from the curl 34 of the inner liner 24. Grasping bottle 12 in one hand and now open unit dose package 10 in the other, the user will insert the neck 76 of bottle 12 into the neck receiving channel 80 of plastic fitment 18 while turning unit dose package 10 into the inverted position shown in FIG. 3. Any slight discrepancy between the diameter of bottle neck 76 and the inner circumference of threaded ring 60 can be accommodated by flexure of ring 60 into spacing channel 82. Unit dose package 10 is typically not completely filled with formula so this inversion of package 10 is accomplished without spillage of the package's contents. With the unit dose package 10 securely affixed atop bottle 12 through the cooperation of the screw threads 68 on threaded ring 60 of plastic fitment 18, and the screw threads 72 on bottle neck 76, thorough mixing of the contents of the unit dose package 10 and the bottle 12 can be accomplished by shaking the assembly. The added headspace created through the attachment of unit dose package 10 to the bottle 12 provides adequate room for efficient formula reconstitution by shaking. Once such reconstitution has been accomplished, the now empty unit dose package 10 may be removed from the neck 76 of bottle 12 and discarded, as shown in FIG. 4. A suitable closure device, such as a well known resilient nipple and seal ring assembly (not shown) may now be applied to bottle neck 76 and the bottle 12 can now be used for its intended function.
The unit dose package 10 in accordance with the present invention has many beneficial attributes. Since each unit dose package was accurately filled, uniformity of the reconstituted product is assured. There is no mess, spillage or wastage associated with the unit dose packages, and essentially sterile condition may be maintained as the unit dose package is kept closed and sealed until immediately prior to usage. The unit dose package 10 of the present invention is intended primarily for use with an 8 oz. plastic nurser bottle 12. However, unit dose packages and bottles in other sizes could also be provided. Also, as was discussed above, the unit dose package of the present invention is equally suited for use with liquid products to be mixed with other liquids. It will thus be apparent that the unit dose package in accordance with the present invention provides an accurate, reproducible device for reconstituting or mixing two constituents in a manner which eliminates mess and saves time in measuring and mixing.
While a preferred embodiment of a unit dose package in accordance with the present invention has been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that a number of changes in, for example, the type of plastics used for the plastic fitment and bottle, the types of heat activated adhesives used, the overall size of the package, and the contents of the package and the reconstituting liquid may be made without departing from the true spirit and scope of the subject invention which is accordingly to be limited only by the following claims.
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A unit dose package, which is usable with a bottle to reconstruct the contents of the package, has a plastic fitment which defines a mouth opening for the package. The plastic fitment is bonded to a wall of the package and has a channel which receives the neck of the bottle. A flexible foil membrane seal is removably attached to this plastic fitment and is covered by a protective overcap.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to press sections of a paper machine and methods for starting and operating such press sections.
2. Description of Related Technology
Paper machine press sections are known, for example, from EP 107,606. According to FIG. 1 of EP 107,606, press roll pairs are provided, each of which forms a press gap or nip. A continuous felt belt that takes up water from the web, which is known as a "dewatering felt," travels through each press gap. Additionally, an impervious, continuous loop pressing belt travels through both press gaps in succession and through some guide rolls. The web to be dewatered comes into contact with the belt in the first press gap and then it is guided by the belt to the second press gap. In this configuration, directly behind each of the two press gaps (i.e. directly downstream of the press gaps with respect to a direction of travel of the web), the dewatering felt cooperating with the press gap separates from the web to be dewatered and thus the transport of the web occurs entirely without the involvement of the dewatering felt. As a result of this, remoistening of the web from the dewatering felts is avoided. In this way, an attempt is made to increase the dewatering capacity of the press part, i,e., to have the web at a higher dry content when it leaves the press part. The disadvantages of such a configuration and other known press parts is that upon starting the press part, blockages and the related operational disturbances sometimes occur, or the course of the paper web is not unequivocally defined, causing disturbances in the operation of the press section.
Furthermore, in spite of the fact that many press section embodiments are known in the art, there is still a demand to increase the performance of known press sections, especially with respect to web dry content, optimum web guidance, symmetrical dewatering, and especially uniformity of the properties of the two sides of the paper web.
SUMMARY OF THE INVENTION
It is an object of the invention to overcome one or more of the problems described above. It is also an object of the invention to provide a press section of a paper machine and method of use thereof which provides trouble free start-up of the press section. It is a further object of the invention to provide a combination of known machine elements in a press section, resulting in a higher dry content of the paper web, tension-free web guidance, symmetrical dewatering of the web and, as a result of this, maximum uniformity on the two sides of the paper with regard to roughness and oil uptake.
According to the invention, a press section of a paper machine includes a pick-up roll, a take-off felt looping about at least the pick-up roll and a connected first pressing element, and a counter element assigned to the first pressing element. The counter element and the first pressing element define a first press unit. A first pressing felt loops about at least the counter element of the first press unit and a second pressing element with a smooth surface. The second pressing element forms a second press unit with the first pressing element. The press section also includes a smooth press belt partially looping around a portion of the second pressing element, a third pressing element looped about by the smooth press belt, and a third counter element assigned to the third pressing element. The third counter element and the third pressing element form a third press unit. A third pressing felt loops about at least the third counter element. A take-off device disposed downstream the third pressing unit with respect to a direction of conveyance of a paper web through the press section is disposed against the smooth press belt.
Also according to the invention, a method of starting and operating a press section is provided.
Other objects and advantages of the invention will be apparent to those skilled in the art from the following detailed description taken in conjunction with the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a press section according to the invention.
FIG. 2 is a schematic view of a second embodiment of a press section according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a press section according to the invention in which a sheet-forming wire having a paper web W thereon is deflected over two rolls. The paper web W is taken off the wire by a take-off felt 1 at a pick-up roll 11. The take-off felt comes from a top portion of the press section, is deflected by a bent felt spreader roll 10, and wraps about the pick-up roll 11. The pick-up roll 11 may be swivelable as indicated by a double arrow "a" Downstream of the pick-up roll 11 with respect to the direction of travel of the web W, the paper web W is introduced to a first press unit in the form of a double-felted press gap or nip defined by rolls 12 and 13. The take-off felt 1 is looped about the roll 13 and the counter roll 12 is looped about by a pressing felt 2. After (i.e., downstream with respect to the direction of conveyance of the web through the section) this first double-felted press gap, the paper web W adheres to the take-off felt 1 lying against the roll 13 and is conveyed to a second press unit in the form of a gap or nip defined by a smooth press roll 14 and the roll 13. The smooth press roll 14 takes up the paper web and guides the web to a smooth press belt 3. A doctor blade device 20 is disposed adjacent to the roll 14 at a location downstream of a contact point between the roll 14 and the press belt 3. The press belt 3 is advanced in a direction toward the roll 14 via a swivelable roll 15 as indicated by the double arrow "b". The press belt takes over the paper web W at the roll 14 and introduces the web to a third press unit. The third press unit is a gap or nip defined by a counter roll 17 and an extended nip press or shoe press unit 18. The counter roll 17 is in the loop of the smooth press belt 3 while the shoe press unit 18 is in a loop formed by a press felt 4. The press felt 4 is introduced to the third press gap 17/18 via a suction roll 16 disposed between the rolls 14 and 18. The roll 16 can be swivelable as illustrated by the double arrow "c". The press felt 4 travels along the same path as the smooth press belt 3 between the roll 16 and the press gap 17/18, so that, after the roll 16, the paper web is guided into the press gap 17/18 while being sandwiched between the felt 4 and the belt 3. After the press gap 17/18, the press felt 4 is immediately removed from the paper web W in order to avoid remoistening of the web. The web W is then conveyed with the smooth press belt 3 to a next deflecting roll. Between the roll 17 and the subsequent deflecting roll, the paper web is picked up by a take-off device illustrated in FIG. 1 by a felt which is pressed against the smooth press belt 3 by a deflecting roll 19. The web W is then guided to further processing. Preferably, the deflecting roll 19 is designed as a suction roll.
The following is a description of a method according to the invention for the start-up of the press section shown in FIG. 1:
(a) Upon start-up of the press section, i.e., swinging the pick-up roll 11 into the wire, it must be ensured that the initial paper web can be guided without difficulty into a broke chest for an amount of time. For this purpose, it is necessary that the guide roll 15 in the press belt 3 can be swung away from the smooth press roll 14 so that there is no contact between the press belt 3 and the roll 14 and the paper web can run all the way to a take-off doctor 20 and then into a broke chest (not shown).
(b) Upon reaching stable running conditions, a transfer strip is cut from the paper web on the wire with a strip cutting device. Then, the press belt 3 is swung toward the press roll 14 and the cut paper strip can be separated from the roll surface directly after a tangent point between the belt 3 and the roll 14 with the aid of an air-blow transfer device which blows the paper onto the press belt. In order to transfer the strip to the smooth press belt 3, it may be necessary to moisten the belt 3 in order to increase adhesion thereto.
(c) It is possible to perform the transfer of the web strip to the belt 3 discussed in paragraph (b) above with a small distance between the press roll 14 and the press belt 3 to ensure that the self-transfer of a full web width is not possible.
(d) At a distance which is as close as possible to the take-off point (i.e., the point where the web leaves the roll 14 and is transferred to the belt 3), the paper web adhering to the press belt 3 is supported by the press felt 4, that is, it is guided between the felt 4 and the press belt 3 so that it cannot separate from the press belt 3 during transport to the next roll press or shoe press. This means that downstream of the take-off point, the paper web is guided to the next press gap sandwiched between the felt 4 and the belt 3.
(e) The first felt guide roll 16 where the sandwiched transport of the paper web begins can be a smooth, grooved, perforated, or suction roll.
(f) The guide roll 16 described in paragraph (e) can be swivelable to provide for the setting of a small gap between the felt 4 and the press belt 3 so that an air film that is drawn between the felt 4 and press belt 3 can be removed on the side later, and that a width-stretch action of the paper web occurs as a result.
(g) Directly downstream of the take-off point onto the smooth belt, a blowing nozzle that extends over the entire width of the machine can be provided to produce an excess of pressure which facilitates the transfer process and prevents tearing of the web.
(h) The looping of the press belt 3 onto the press roll 14 must be minimal so that a differential velocity between the press roll 14 and the press belt 3 can be set.
(i) Downstream of the shoe press 18, the transfer strip of the paper web is first directly drawn to and taken by a suction roll of a first drying screen and guided to a doctor of a first drying cylinder from which the web is guided away on a broke-handling belt disposed thereunder and then into another broke chest or a cellar.
(j) A blowing device can support the transfer of the paper web to a first dryer felt.
(k) The guide roll 15 in the press belt upstream of the take-up point can be swivelable in order to optimize transfer.
(l) The common press belt/dryer wire contact section must be minimal in order to make possible a significant advance of the first dryer wire 5 in comparison to the press belt. This is necessary so as to pre-stress the paper web correspondingly before the first dryer group. The extending section for the paper is the section of paper between the shoe press 18 and the contact section between drying cylinder/dryer felt.
(m) When the transfer strip of the paper web runs stably through the dryer portion of the machine, one can operate with the strip cutting device on the wire at "full width", i.e., from strip position to the drive side. As a result of this, the full web width will run through the machine automatically.
(n) When a broke chest is present under cylinder 14, one can operate at "full width" immediately after transfer of the strip through the shoe press 18 to the cylinder 19.
FIG. 2 shows a press section having elements, 1'-4', 10'-18', and 20' similar in function and design to the elements, 1-4, 10-18, and 20, respectively, shown in FIG.1. However, the take-off of the paper web W from the smooth press belt 3' is done directly via a first cylinder 19' of a connected dryer group.
The following is a description of a method according to the invention for the start-up of the press section shown in FIG. 2:
(a) Upon start-up of the press section, i.e., swinging the pick-up roll 11' into the wire, it must be ensured that the initial paper web can be guided without difficulty into a broke chest for an amount of time. For this purpose, it is necessary that the guide roll 15' in the press belt 3' can be swung away from the smooth press roll 14' so that there is no contact between the press belt 3' and the roll 14' and the paper web can run all the way to a take-off doctor 20' and then into a broke chest (not shown).
(b) Upon reaching stable running conditions, a transfer strip is cut from the paper web on the wire with a strip cutting device. Then, the press belt 3' is swung toward the press roll 14' and the cut paper strip can be separated from the roll surface directly after a tangent point between the belt 3' and the roll 14' with the aid of an air-blow transfer device which blows the paper onto the press belt. In order to transfer the strip to the smooth press belt 3', it may be necessary to moisten the belt 3' in order to increase adhesion thereto.
(c) It is possible to perform the transfer of the web strip to the belt 3' discussed in paragraph (b) above with a small distance between the press roll 14' and the press belt 3' to ensure that the self-transfer of a full web width is not possible.
(d) At a distance which is as close as possible to the take-off point (i.e., the point where the web leaves the roll 14' and is transferred to the belt 3'), the paper web adhering to the press belt 3' is supported by the press felt 4', that is, it is guided between the felt 4' and the press belt 3' so that it cannot separate from the press belt 3' during transport to the next roll press or shoe press. This means that downstream of the take-off point, the paper web is guided to the next press gap sandwiched between the felt 4' and the belt 3'
(e) The first felt guide roll 16' where the sandwiched transport of the paper web begins can be a smooth, grooved, perforated, or suction roll.
(f) The guide roll 16' described in paragraph (e) can be swivelable to provide for the setting of a small gap between the felt 4' and the press belt 3' so that an air film that is drawn between the felt 4' and press belt 3' can be removed on the side later, and that a width-stretch action of the paper web occurs as a result.
(g) Directly downstream of the take-off point onto the smooth belt, a blowing nozzle that extends over the entire width of the machine can be provided to produce an excess of pressure which facilitates the transfer process and prevents tearing of the web.
(h) The looping of the press belt 3' onto the press roll S 14' must be minimal so that a differential velocity between the press roll 14' and the press belt 3' can be set.
(i) Downstream of the shoe press 18', the transfer strip of the paper web is first directly drawn to and taken by a suction roll of a first drying screen and guided to a doctor of a first drying cylinder from which the web is guided away on a broke-handling belt disposed thereunder and then into another broke chest or a cellar.
(j) A blowing device can support the transfer of the paper web to a first dryer felt.
(k) A guide roll 22 in the press belt disposed downstream of the take-up point can be swivelable (as indicated by the double arrow "d") in order to optimize transfer.
(l) The common press belt/dryer cylinder contact section must be minimal in order to make possible a significant advance of a first dryer group, generally 25, in comparison to the press belt 3'. This is necessary so as to pre-stress the paper web correspondingly before the first dryer group. The extending section for the paper is the section of paper between the shoe press 18' and the contact section between drying cylinder/dryer felt.
(m) When the transfer strip of the paper web runs stably through the dryer portion of the machine, one can operate with the strip cutting device on the wire at "full width", i.e., from strip position to the drive side. As a result of this, the full web width will run through the machine automatically.
(n) When a broke chest is present under cylinder 14', one can operate at "full width" immediately after transfer of the strip through the shoe press 18' to the cylinder 19'.
In summary, the press sections according to the invention shown in FIGS. 1 and 2 have the following advantages:
strip transfer or web transfer can be performed in stages;
the strip or full web width can be guided away from the pressing elements without difficulty;
after each transfer point, where the paper becomes longer, a positive velocity difference can be set and, in spite of this, the paper web is fully supported.
The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications within the scope of the invention will be apparent to those skilled in the art.
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A press section of a paper machine includes a pick-up roll, a take-off felt looping about at least the pick-up roll and a connected first pressing element, and a counter element assigned to the first pressing element. The counter element and the first pressing element define a first press unit. A first pressing felt loops about at least the counter element of the first press unit and a second pressing element with a smooth surface. The second pressing element forms a second press unit with the first pressing element. The press section also includes a smooth press belt partially looping around a portion of the second pressing element, a third pressing element looped about by the smooth press belt, and a third counter element assigned to the third pressing element. The third counter element and the third pressing element form a third press unit. A third pressing felt loops about at least the third counter element. A take-off device disposed downstream the third pressing unit with respect to a direction of conveyance of a paper web through the press section is disposed against the smooth press belt.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of the following U.S. Provisional Application No. 61/248,338, filed Oct. 2, 2009, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to the use of various 2-oxothiazole or 2-oxooxazole compounds for use in the prevention or treatment of chronic inflammatory disorders such as glomerulonephritis, rheumatoid arthritis and psoriasis. The invention also relates to certain new 2-oxothiazole or 2-oxo-oxazole compounds, pharmaceutical compositions comprising said compounds and to new processes for the manufacture thereof.
Mammalian cells contain a large number of phospholipases that hydrolyse phospholipids in a structurally specific manner for production of a myriad of products, many of which have potent biological activity. There has been considerable interest in characterising these enzymes because of their role in production of lipid mediators of inflammation. Since the first studies 20 years ago showing that mammalian cells contain a cystolic calcium dependent phospholipase specific for arachidonic acid, an extensive amount of evidence has substantiated a primary role for cPLA 2 as the key enzyme that mediates the release of arachidonic acid for the production of eicosanoids.
The enzyme cPLA 2 contributes to the pathogenesis of a variety of diseases particularly those in which inflammation plays a primary role implicating a role for inflammatory lipid mediators in disease pathogenesis. The inhibition therefore of such lipase enzymes offers a potential therapy for inflammatory conditions in particular chronic inflammatory conditions such as those above, psoriasis and glomerulonephritis.
The phospholipases are a group of enzymes that release unsaturated fatty acids from the sn2 position of membrane phospholipids. Once released, the fatty acids are converted by various enzymes into biologically very important signalling molecules. Release of arachidonate initiates the arachidonate cascade leading to the synthesis of eicosanoids such as prostaglandins.
Eicosanoids are important in a variety of physiological processes and play a central role in inflammation. In Inflammation, Vol. 18, No. 1 1994, Andersen et al identify the presence of certain phospholipases in psoriatic human skin.
It is therefore believed that inhibition of phospholipase enzymes should have potential in curing some of the inflammatory symptoms, including epidermal hyperproliferation due to increased leukotriene production, related to eicosanoid production and cell activation in both epidermis and dermis in psoriasis.
Psoriasis is a common, chronic, inflammatory skin disorder. Psoriatic tissue is characterised by chronic inflammation in both epidermis and dermis, the disease being further characterised by hyperplasia of epidermal keratinocytes, fibroblast activation, alteration of eicosanoid metabolism, and leukocyte infiltration.
Glomerulonephritis, also known as glomerular nephritis, abbreviated GN, is a renal disease characterized by inflammation of the glomeruli, or small blood vessels in the kidneys. It may present with isolated hematuria and/or proteinuria or as a nephrotic syndrome, acute renal failure, or chronic renal failure. Glomerulonephritis is categorised into several different pathological patterns, which are broadly grouped into non-proliferative or proliferative types.
The glomerulus is a unique vascular network with three specialised types of cell: the endothelial cell, the mesangial cell and the visceral epithelial cell
Mesangial cells (MC) serve a number of functions in the renal glomerular capillary including structural support of the capillary tuft, modulation of the glomerular hemodynamics and a phagocytic function allowing removal of macromolecules and immune complexes. The proliferation of MC is a prominent feature of glomerular disease including IgA nephropathy, membranoproliferative glomerulonephritis, lupus nephritis, and diabetic nephropathy.
Reduction of MC proliferation in glomerular disease models by treatment with, for example, a low protein diet has been shown to produce extracellular matrix expansion and glomerulosclerotic changes. MC proliferation inhibitors may therefore offer therapeutic opportunities for the treatment of proliferative glomerular disease.
Mesangial proliferative glomerulonephritis is a form of glomerulonephritis which involves inflammation at the kidney glomeruli. The mesangial cells which are a part of the glomerular capillaries increase in size giving the glomeruli a lumpy appearance. The disorder usually causes nephritic syndrome which represents protein loss in the urine. It may be present as acute, chronic or rapidly progressive glomerulonephritis and may progress to chronic renal failure.
The present inventors seek new treatments for, inter alia, chronic inflammatory conditions such as GN and psoriasis.
SUMMARY OF THE INVENTION
The present inventors have surprisingly found that certain 2-oxo-thiazoles or 2-oxo-oxazoles are ideal cPLA 2 inhibitors and offer new therapeutic routes to the treatment of chronic inflammatory disorders.
2-oxothiazole type structures are not new. In Bioorganic and Medicinal Chemistry 16 (2008) 1562-1595, there is a review of chemistry in this field. 2-oxo (benz)thiazoles carrying peptides or amino acids on the 2-position (i.e. where the 2-oxo group forms part of the backbone of an amino acid) are known in the art as thrombin inhibitors.
Also reported are certain hydrolase and transferase inhibitors in particular having a 2-oxo-oleyl side chain. Similar compounds as fatty acid amide hydrolase inhibitors are reported in J Med Chem. Vol. 51, No. 237329-7343. Their potential as inhibitors of cPLA 2 is not discussed.
A wider variety of 2-oxo-oxazole compounds are known from these papers. The majority of these compounds are either unsubstituted oxazole rings or they carry substituents in the position adjacent the oxygen atom. Their potential as inhibitors of cPLA 2 is not discussed.
Never before therefore, have the compounds claimed herein been identified as potential inhibitors of phospholipase enzymes and hence no link with chronic inflammatory conditions has been made.
Thus, viewed from one aspect the invention provides a compound of formula (I)
wherein X is O or S;
R 1 is H, OH, SH, nitro, NH 2 , NHC 1-6 alkyl, N(C 1-6 alkyl) 2 , halo, haloC 1-6 alkyl, CN, C 1-6 -alkyl, OC 1-6 alkyl, C 2-6 -alkenyl, C 3-10 cycloalkyl, C 6-10 aryl, C 1-6 alkylC 6-10 aryl, heterocyclyl, heteroaryl, CONH 2 , CONHC 1-6 alkyl, CON(C 1-6 alkyl) 2 , OCOC 1-6 alkyl, C 1-6 alkylCOOH, C 1-6 alkylCOOC 1-6 alkyl or is an acidic group, such as a group comprising a carboxyl, phosphate, phosphinate, sulfate, sulfonate, or tetrazolyl group;
R 2 is as defined for R 1 or R 1 and R 2 taken together can form a 6-membered aromatic ring optionally substituted by up to 4 groups R 5 ;
R 3 is H, halo (preferably fluoro), or CHal 3 (preferably CF 3 );
each R 5 is defined as for R 1 ;
V 1 is a covalent bond, —O—, or a C 1-20 alkyl group, or C 2-20 -mono or multiply unsaturated alkenyl group; said alkyl or alkenyl groups being optionally interrupted by one or more heteroatoms selected from O, NH, N(C 1-6 alkyl), S, SO, or SO 2 ;
M 1 is absent or is a C 5-10 cyclic group or a C 5-15 aromatic group (e.g. C 6-14 aromatic group); and
R 4 is H, halo, OH, CN, nitro, NH 2 , NHC 1-6 alkyl, N(C 1-6 alkyl) 2 , haloC 1-6 alkyl, a C 1-20 alkyl group, or C 2-20 -mono or multiply unsaturated alkenyl group, said C 1-20 alkyl or C 2-20 alkenyl groups being optionally interrupted by one or more heteroatoms selected from O, NH, N(C 1-6 alkyl), S, SO, or SO 2 ;
with the proviso that the group V 1 M 1 R 4 as a whole provides at least 4 backbone atoms from the C(R 3 ) group;
or a salt, ester, solvate, N-oxide, or prodrug thereof;
for use in the treatment of a chronic inflammatory condition.
Viewed from another aspect the invention provides a compound of formula (II)
wherein R 1 , R 2 , R 3 , R 5 and R 4 M 1 V 1 are as hereinbefore defined;
or a salt, ester, solvate, N-oxide, or prodrug thereof;
with the proviso that R 4 M 1 V 1 C(R 3 ) is not oleyl.
Viewed from another aspect the invention provides a compound of formula (III)
wherein R 6 is H, C 1-6 alkyl, COOH, COOC 1-6 alkyl, CONH 2 , CONHC 1-6 alkyl, CON(C 1-6 alkyl) 2 , C 1-6 alkylCOOH, C 1-6 alkylCOOC 1-6 alkyl;
R 7 is H;
wherein R 3 is as hereinbefore defined;
V 1 is a covalent bond, —O—, or a C 1-20 alkyl group, or C 2-20 -mono or multiply unsaturated alkenyl group;
M 1 is a covalent bond or is a C 5-10 cyclic group or a C 5-10 aromatic group; and
R 4 is H, halo, OH, CN, nitro, NH 2 , NHC 1-6 alkyl, N(C 1-6 alkyl) 2 , haloC 1-6 alkyl, a C 1-20 alkyl group, or C 2-20 -mono or multiply unsaturated alkenyl group, said alkyl or alkenyl groups being optionally interrupted by one or more heteroatoms selected from O, NH, N(C 1-6 alkyl), S, SO, or SO 2 ;
or a salt, ester, solvate, N-oxide, or prodrug thereof
with the proviso that R 4 M 1 V 1 C(R 3 ) is not oleyl or —(CH 2 ) 6 Ph.
Viewed from another aspect the invention provides a compound of formula (I′)
wherein X is O or S;
R 1 is H, OH, SH, nitro, NH 2 , NHC 1-6 alkyl, N(C 1-6 alkyl) 2 , halo, haloC 1-6 alkyl, CN, C 1-6 -alkyl, OC 1-6 alkyl, C 2-6 -alkenyl, C 3-10 cycloalkyl, C 6-10 aryl, C 1-6 alkylC 6-10 aryl, heterocyclyl, heteroaryl, CONH 2 , CONHC 1-6 alkyl, CON(C 1-6 alkyl) 2 , OCOC 1-6 alkyl, C 1-6 alkylCOOH, C 1-6 alkylCOOC 1-6 alkyl or is an acidic group, such as a group comprising a carboxyl, phosphate, phosphinate, sulfate, sulfonate, or tetrazolyl group;
R 2 is as defined for R 1 or R 1 and R 2 taken together can form a 6-membered aromatic ring optionally substituted by up to 4 groups R 5 ;
each R 3′ is the same or different and is H, C 1-6 alkylCOOR a where R a is H or C 1-6 alkyl, halo (preferably fluoro), or CHal 3 (preferably CF 3 );
each R 5 is defined as for R 1 ;
V 1′ is a covalent bond, —O—, —NHCOC 0-6 alkyl- (i.e. where NH is adjacent the CR 3′ group), a C 1-20 alkyl group, or C 2-20 -mono or multiply unsaturated alkenyl group; said alkyl or alkenyl groups being optionally interrupted by one or more heteroatoms selected from O, NH, N(C 1-6 alkyl), S, SO, or SO 2 ;
M 1 is absent or is a C 5-10 cyclic group or a C 5-15 aromatic group (e.g. C 6-14 aromatic group); and
R 4 is H, halo, OH, CN, nitro, NH 2 , NHC 1-6 alkyl, N(C 1-6 alkyl) 2 , haloC 1-6 alkyl, a C 1-20 alkyl group, or C 2-20 -mono or multiply unsaturated alkenyl group, said C 1-20 alkyl or C 2-20 alkenyl groups being optionally interrupted by one or more heteroatoms selected from O, NH, N(C 1-6 alkyl), S, SO, or SO 2 ;
with the proviso that the group V 1′ M 1 R 4 as a whole provides at least 4 backbone atoms from the C(R 3′ ) 2 group;
or a salt, ester, solvate, N-oxide, or prodrug thereof
with the proviso that R 4 M 1 V 1 C(R 3′ ) 2 is not oleyl. It is also preferred if R 4 M 1 V 1 C(R 3′ ) 2 is not CH 2 Ph.
The invention also concerns a compound of formula (I′) as hereinbefore defined but without the disclaimer for use in the treatment of a chronic inflammatory condition.
Viewed from another aspect the invention provides a compound of formula (III′)
wherein R 6 , R 7 , R 3′ , V 1′ , M 1 , R 4 are as hereinbefore defined;
with the proviso that R 4 M 1 V 1 C(R 3 ) is not oleyl or —(CH 2 ) 6 Ph.
Viewed from another aspect the invention provides a pharmaceutical composition claim comprising a compound of formula (I′), (II), (III) or (III′) as hereinbefore defined.
Viewed from another aspect the invention provides a compound of formula (I′), (II), (III) or (III′) as hereinbefore defined for use in therapy.
Viewed from another aspect the invention provides use of the a compound of formula (I) or (I′) as hereinbefore defined in the manufacture of a medicament for the treatment of a chronic inflammatory condition.
Viewed from another aspect the invention provides a method of treating a chronically inflammatory disorder comprising administering to a patient an effective amount of a compound of formula (I) or (I′) as hereinbefore defined.
DEFINITIONS
In this specification, unless stated otherwise, the term “alkyl” includes both straight and branched chain alkyl radicals and may be methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, i-pentyl, t-pentyl, neo-pentyl, n-hexyl or i-hexyl, t-hexyl.
The term “cycloalkyl” refers to an optionally substituted carbocycle containing no heteroatoms, including mono-, and multicyclic saturated carbocycles, as well as fused ring systems. Cycloalkyl includes such fused ring systems as spirofused ring systems. Examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like.
The term “alkenyl” includes both straight and branched chain alkenyl radicals. The term alkenyl refers to an alkenyl radicals one or more double bonds and may be, but is not limited to vinyl, allyl, propenyl, i-propenyl, butenyl, i-butenyl, crotyl, pentenyl, i-pentenyl and hexenyl.
The term “aryl” refers to an optionally substituted monocyclic or bicyclic hydrocarbon ring system containing at least one unsaturated aromatic ring. Examples and suitable values of the term “aryl” are phenyl, naphtyl, 1,2,3,4-tetrahydronaphthyl, indyl, indenyl and the like.
In this specification, unless stated otherwise, the term “heteroaryl” refers to an optionally substituted monocyclic or bicyclic unsaturated, aromatic ring system containing at least one heteroatom selected independently from N, O or S. Examples of “heteroaryl” may be, but are not limited to thiophene, thienyl, pyridyl, thiazolyl, isothiazolyl, furyl, pyrrolyl, triazolyl, imidazolyl, oxadiazolyl, oxazolyl, isoxazolyl, pyrazolyl, imidazolonyl, oxazolonyl, thiazolonyl, tetrazolyl and thiadiazolyl, benzoimidazolyl, benzooxazolyl, benzothiazolyl, tetrahydrotriazolopyridyl, tetrahydrotriazolopyrimidinyl, benzofuryl, thionaphtyl, indolyl, isoindolyl, pyridonyl, pyridazinyl, pyrazinyl, pyrimidinyl, quinolyl, phtalazinyl, naphthyridinyl, quinoxalinyl, quinazolyl, imidazopyridyl, oxazolopyridyl, thiazolopyridyl, pyridyl, imidazopyridazinyl, oxazolopyridazinyl, thiazolopyridazinyl, cynnolyl, pteridinyl, furazanyl, benzotriazolyl, pyrazolopyridinyl, purinyl and the like.
In this specification, unless stated otherwise, the term “heterocycle” refers to an optionally substituted, monocyclic or bicyclic saturated, partially saturated or unsaturated ring system containing at least one heteroatom selected independently from N, O and S, e.g. piperidinyl, morpholino, or piperazinyl.
Any cyclic group can be a cycloalkyl group, cycloalkenyl group or heterocyclic group.
Any aromatic group can be aryl or heteroaryl in nature, e.g. phenyl, naphthyl or pyridyl.
An acidic group is one comprising a carboxyl, phosphate, phosphinate, sulfate, sulfonate, or tetrazolyl group, e.g. an C 1-6 alkyl linked to a carboxyl, phosphate, phosphinate, sulfate, sulfonate, or tetrazolyl group. Highly preferred acidic groups are COOH, COOC 1-6 alkyl, or C 1-6 alkyl substituted by COOH, COOC 1-6 alkyl or C 6-10 aryl group substituted by COOH, COOC 1-6 alkyl.
DETAILED DESCRIPTION OF INVENTION
It is preferred if X is S and the ring system is a thiazole system.
It is preferred if R 1 is hydrogen.
It is preferred if R 2 is hydrogen or is an acidic group, e.g. a group comprising a carboxylic group or derivative thereof (i.e. a COO group). Thus, R 2 may be COOH, or an ester, e.g. alkyl ester thereof. The acid group may also be spaced apart from the ring by some form of linking chain such as an alkylene chain or an aromatic group. Highly preferred groups are COOH, COOC 1-6 alkyl and C 1-6 alkylCOOH.
It is believed that the presence of a carboxyl functional group attached to the heterocyclic ring enhances interaction of the compound with the active site of the phospholipase enzyme, in particular, the side chain of arginine 200. This arginine is believed to carry a free guanidine group so any substituent which can favourably interact with this guanidine is preferred at the R 1 and/or R 2 position.
In one embodiment R 1 and R 2 can be taken together to form a ring system such as a phenyl ring or pyridine ring. Where a pyridine ring system forms the N atom is preferably in the 4-position of the ring (S=1 position, N=3, N=4). Preferably the ring system will be a carbon ring system, e.g. forming a benzothiazole type structure. If such a ring system is formed, it may be substituted preferably by 1 or 2 groups R 5 . Preferences for R 5 are the same as those for R 2 . Preferably the R 5 group is positioned on the 5-position of the ring (where S is the 1-position and N is the 3-position). Ideally however such a ring system is unsubstituted.
Preferred compounds in this regard are of formula (VII)
where the substituents are as hereinbefore defined and Z is C or N.
It is especially preferred if at least one of R 1 and R 2 (especially R 1 ) is hydrogen. The heterocyclic ring is ideally only monosubstituted. In a further preferred embodiment both R 1 and R 2 are hydrogen.
R 3 is preferably hydrogen or, in a highly preferred embodiment, R 3 is halo, especially fluoro. It is believed that the presence of the F atom adjacent the carbonyl enhances the activity of the carbonyl group and may also interact favourably with the active site in the cPLA 2 enzyme, in particular IVa PLA 2 .
It is preferred if one R 3′ is H. It is also preferable if one R 3′ is halo, especially fluoro. The presence of two fluoro atoms as R 3′ is also preferred. It is believed that the presence of the F atom adjacent the carbonyl enhances the activity of the carbonyl group and may also interact favourably with the active site in the cPLA 2 enzyme, in particular IVa PLA 2 .
The discussion of the group V 1 M 1 R 4 which follows also applies to V 1 M 1 R 4 . The group V 1 M 1 R 4 as a whole provides at least 4 backbone atoms from the C(R 3 ) group. Preferably, V 1 M 1 R 4 provides at least 5 backbone atoms, more preferably at least 7 backbone atoms especially at least 10 backbone atoms from the C(R 3 ) group. For the avoidance of doubt, where there is an aromatic group in the backbone, the backbone is considered to follow the shortest route around the ring. Thus, for a 1,4-phenyl group, that would constitute 4 backbone atoms. A 1,3 linked 5 membered ring in the backbone would constitute 3 backbone atoms and so on.
V 1 (or V 1′ ) is preferably an C 1-15 -alkyl group, C 2-20 -alkenyl group or is a —C 1-6 alkylO-group (i.e. where the O atom bonds to M 1 ). Any alkenyl group can have one or more than one double bond. Where more than one double bond is present, it is preferred if these are non conjugated. Double bonds will preferably take the cis form. Preferred alkyl groups for V 1 (or V 1′ ) include C 1-6 -alkyl.
It is especially preferred if any alkyl or alkenyl group in V 1 (or V 1′ ) is linear.
V 1′ may also represent —O—, or an amide linkage NHCO which may then optionally carry an alkyl chain of up to 6 carbon atoms. That chain is preferably linear. The NH part of the linkage is adjacent the CR 3′ group.
Preferably M 1 is either absent or is an C 6-10 aryl group, especially a phenyl group. Alternatively, M 1 may be a bicyclic aromatic group such as decalin. A further preferred embodiment is where M 1 represents a biphenyl group, i.e. a C 5-15 aromatic group in which two phenyl groups are directly linked. Where M 1 is a phenyl group, V 1 or V 1′ and R 4 are preferably attached in the 1 and 4 positions of the ring, i.e. they are para to each other.
R 4 is preferably an H atom, C 1-10 alkyl group or an C 1-10 alkoxy group.
In one embodiment it is preferred in any compound of the invention that R 4 M 1 V 1 C(R 3 ) or R 4 M 1 V 1′ C(R 3′ ) 2 is not oleyl or —(CH 2 ) 6 Ph.
Thus, a still more preferred compound of the invention is of formula (VI)
wherein R 1 is H;
R 2 is H, COOH, COOC 1-6 alkyl, C 1-6 alkylCOOH, or C 1-6 alkylCOOC 1-6 alkyl;
R 3 is H or F;
V 1 is C 1-15 -alkyl group, C 2-20 -alkenyl group, —O—, or is a —C 1-6 -alkylO-group;
M 1 is absent or is a phenyl group;
R 4 is H, C 1-10 alkyl group or an C 1-10 alkoxy group.
In further highly preferred combinations:
1. V 1 is C 1-15 -alkyl group or C 2-20 -alkenyl group, M 1 is absent and R 4 is H.
2. V 1 is C 1-6 -alkyl group or is a —C 1-6 -alkylO group, M 1 is a phenyl group, and R 4 is H or C 1-6 alkoxy (where the O atom is adjacent the M 1 group);
3. R 4 V 1 M 1 represents a C 10-20 linear alkyl group.
Also preferred are options 1-3 above in which V 1 is V 1′
In a highly preferred embodiment, the invention provides the compounds in the examples.
Synthesis
The manufacture of the compounds of the invention typically involves known literature reactions. For example, the formation of an 2-oxothiazole, the precursor to many of the claimed compounds, can be achieved by reaction of an aldehyde XCOH with thiazole in the presence of a base and subsequent oxidation of the hydroxyl to a ketone. The X group is obviously selected to form the desired R 4 M 1 V 1 or R 4 M 1 V 1′ group or a precursor thereof.
These reactions are summarised in Scheme 1 below.
It will be appreciated that in the scheme above and many of those below, specific reagents and solvents may mentioned to aid the skilled man in carrying out the reactions described. The skilled man will appreciate however that a variety of different conditions, reagents, solvents, reactions etc could be used to effect the chemistry described and the conditions quoted are not intended to be limiting on the reactions described.
An alternative strategy involves the reaction of an alkoxy amide XCON(Oalkyl) with thiazole in base which affords 2-oxothiazoles directly. This reaction is summarised in scheme 2.
The inventors have however found a new and preferred way of forming 2-oxothiazoles and this forms a still yet further aspect of the invention. The new process involves the reaction of an oxo-morpholino structure with thiazole, typically in the presence of a base. This reaction affords 2-oxo thiazoles directly and is a new reaction.
Thus viewed from another aspect the invention provides a process for the formation of a 2oxothiazole comprising reacting a compound of formula (IV)
wherein Y is an organic group, e.g. a group R 4 M 1 V 1 CH(R 3 ),
with an optionally substituted thiazole in the presence of a base so as to form an optionally substituted compound of formula (V)
This reaction is effected in the presence of a base, e.g. nBuLi or the like. Ideally, the reaction is effected at low temperature, e.g. at 0° C. or below so in an ice bath, or other known cooling system, e.g. liquid ammonia.
It will be appreciated that this reaction is preferably used to form compounds of formula (I) or (II) or (III) or their (I′)/(III′) analogues and this forms a still further aspect of the invention. It will be preferred therefore if the definition if Y reflects the group R 4 M 1 V 1 CH(R 3 ) or R 4 M 1 V 1 C(R 3 ) 2 or forms a precursor thereto. It will also be preferred if the thiazole used reflects the preferred thiazole reactant required to make a compound of the invention, i.e. carrying the necessary R 1 /R 2 substituents etc. The reaction is however more generally applicable so variable Y is broadly defined and the thiazole may be optionally substituted.
It is believed that the morpholino intermediates used in this reaction are new and these form a further aspect of the invention. Thus, viewed from another aspect the invention provides an intermediate compound of formula (IX)
wherein R 4 M 1 V 1 CH(R 3 ) is as hereinbefore defined.
Viewed from another aspect the invention provides an intermediate compound of formula (IX′)
wherein R 4 M 1 V 1 C(R 3 ) 2 is as hereinbefore defined.
There are still further ways of developing a 2-oxo thiazole ring carrying a substituent. The ring itself can be generated from a thioamide as described in scheme 3.
As noted above, an interesting class of compounds of the invention are those having a fluoro atom adjacent the carbonyl. This is conveniently introduced before attachment of the ring system by conventional chemistry. A hydroxy group may be converted to a fluoro group using Diethylaminosulfur trifluoride (DAST) for example. This chemistry is elucidated below:
The formed compound can react with thiazole as described above. Variations of the substituents on the heterocyclic rings and manipulation of the side chain binding the carbonyl can be achieved using all manner of synthetic techniques which the skilled man will know. Guidance is offered in the examples as to how to make a wide variety of compounds and the principles described can be extended to the compounds encompassed by the claims.
The principles described above for preparing thiazoles can be extended to the oxazole species.
Intermediates
Various intermediates are also new and form a further aspect of the invention. In particular, the invention covers the reduced analogue of the final 2-oxoheterocycle, i.e. a 2-hydroxy analogue. Thus, viewed from another aspect the invention provides a compound of formula (VIII)
wherein R 1 , R 2 , R 3 , R 3′ , R 5 and R 4 M 1 V 1 /R 4 M 1 V 1′ are as hereinbefore defined;
or a salt, ester, solvate, N-oxide, or prodrug thereof;
preferably with the proviso that R 4 M 1 V 1 C(R 3 ) or R 4 M 1 V 1 C(R 3 ) 2 is not oleyl.
Chronic Inflammatory Disorders
The compounds of the invention are used in the treatment of chronic inflammatory disorders, in particular those associated with phospholipase inhibition.
Preferably, any compound of the invention will achieve 90% inhibition against IVa PLA 2 .
Preferably, compounds of the invention inhibit IVa cPLA 2 at a low μM range such as 5 μM or less, preferably 4 μM or less.
It is further preferred that the compounds of the invention show greater inhibition of IVa cPLA 2 than iPLA 2 or sPLA 2 according to published assays for these enzymes (see, for example, Yang, H et al. (1999) Anal. Biochem. 269: 278). Ideally, the compounds of the invention show limited or no inhibition of iPLA 2 or sPLA 2 and they are therefore highly specific for the IVa cPLA 2 enzyme.
Specific diseases of interest are glomerulonephritis, inflammatory dermatoses such as psoriasis and rheumatoid arthritis.
Further conditions of interest include other inflammatory dermatoses such as atopic dermatitis, allergic contact dermatitis, seborrheic dermatitis, pityriasis rosea, lichen planus and drug eruptions.
Furthermore the compounds of the invention may have use in the treatment of other types of arthritis and dermatoses, inflammatory CNS diseases, multiple sclerosis, chronic obstructive pulmonary disease, chronic lung inflammatory conditions, inflammatory bowel disease such as ulcerative colitis and crohns disease and cardiovascular disease.
Thus viewed from a further aspect the invention provides for the treatment of any of the conditions listed above using the compounds of the invention.
Formulation
The compounds of the invention are preferably formulated as pharmaceutically acceptable compositions. The phrase “pharmaceutically acceptable”, as used in connection with compositions of the invention, refers to molecular entities and other ingredients of such compositions that are physiologically tolerable and do not typically produce untoward reactions when administered to a mammal (e.g. human). Preferably, as used herein, the term “pharmaceutically acceptable” means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopoeia or other generally recognized pharmacopoeia for use in mammals, and more particularly in humans.
The term “carrier” applied to pharmaceutical compositions of the invention refers to a diluent, excipient, or vehicle with which an active compound is administered. Such pharmaceutical carriers can be sterile liquids, such as water, saline solutions, aqueous dextrose solutions, aqueous glycerol solutions, and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Suitable pharmaceutical carriers are described in “Remington's Pharmaceutical Sciences” by E. W. Martin, 18th Edition, incorporated by reference. Particularly preferred for the present invention are carriers suitable for immediate-release, i.e., release of most or all of the active ingredient over a short period of time, such as 60 minutes or less, and make rapid absorption of the drug possible.
The compounds of the invention can be administered in salt, solvate, prodrug or ester form, especially salt form. Typically, a pharmaceutical acceptable salt may be readily prepared by using a desired acid. The salt may precipitate from solution and be collected by filtration or may be recovered by evaporation of the solvent. For example, an aqueous solution of an acid such as hydrochloric acid may be added to an aqueous suspension of a compound of formula (I) and the resulting mixture evaporated to dryness (lyophilised) to obtain the acid addition salt as a solid. Alternatively, a compound of formula (I) may be dissolved in a suitable solvent, for example an alcohol such as isopropanol, and the acid may be added in the same solvent or another suitable solvent. The resulting acid addition salt may then be precipitated directly, or by addition of a less polar solvent such as diisopropyl ether or hexane, and isolated by filtration.
Suitable addition salts are formed from inorganic or organic acids which form non-toxic salts and examples are hydrochloride, hydrobromide, hydroiodide, sulphate, bisulphate, nitrate, phosphate, hydrogen phosphate, acetate, trifluoroacetate, maleate, malate, fumarate, lactate, tartrate, citrate, formate, gluconate, succinate, pyruvate, oxalate, oxaloacetate, trifluoroacetate, saccharate, benzoate, alkyl or aryl sulphonates (eg methanesulphonate, ethanesulphonate, benzenesulphonate or p-toluenesulphonate) and isethionate. Representative examples include trifluoroacetate and formate salts, for example the bis or tris trifluoroacetate salts and the mono or diformate salts, in particular the tris or bis trifluoroacetate salt and the monoformate salt.
Those skilled in the art of organic chemistry will appreciate that many organic compounds can form complexes with solvents in which they are reacted or from which they are precipitated or crystallized. These complexes are known as “solvates”. For example, a complex with water is known as a “hydrate”. Solvates of the compounds of the invention are within the scope of the invention. The salts of the compound of Formula (I) may form solvates (e.g. hydrates) and the invention also includes all such solvates.
The term “prodrug” as used herein means a compound which is converted within the body, e.g. by hydrolysis in the blood, into its active form that has medical effects.
The compounds of the invention are proposed for use in the treatment of, inter alia, chronic inflammatory disorders. By treating or treatment is meant at least one of:
(i). preventing or delaying the appearance of clinical symptoms of the disease developing in a mammal;
(ii). inhibiting the disease i.e. arresting, reducing or delaying the development of the disease or a relapse thereof or at least one clinical or subclinical symptom thereof, or
(iii). relieving or attenuating one or more of the clinical or subclinical symptoms of the disease.
The benefit to a subject to be treated is either statistically significant or at least perceptible to the patient or to the physician. In general a skilled man can appreciate when “treatment” occurs.
The word “treatment” is also used herein to cover prophylactic treatment, i.e. treating subjects who are at risk of developing a disease in question.
The compounds of the invention can be used on any animal subject, in particular a mammal and more particularly to a human or an animal serving as a model for a disease (e.g. mouse, monkey, etc.).
An “effective amount” means the amount of a compound that, when administered to an animal for treating a state, disorder or condition, is sufficient to effect such treatment. The “effective amount” will vary depending on the compound, the disease and its severity and the age, weight, physical condition and responsiveness of the subject to be treated and will be ultimately at the discretion of the attendant doctor.
While it is possible that, for use in the methods of the invention, a compound of formula I may be administered as the bulk substance, it is preferable to present the active ingredient in a pharmaceutical formulation, for example, wherein the agent is in admixture with a pharmaceutically acceptable carrier selected with regard to the intended route of administration and standard pharmaceutical practice.
The term “carrier” refers to a diluent, excipient, and/or vehicle with which an active compound is administered. The pharmaceutical compositions of the invention may contain combinations of more than one carrier. Such pharmaceutical carriers can be sterile liquids, such as water, saline solutions, aqueous dextrose solutions, aqueous glycerol solutions, and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Water or aqueous solution saline solutions and aqueous dextrose and glycerol solutions are preferably employed as carriers, particularly for injectable solutions. Suitable pharmaceutical carriers are described in “Remington's Pharmaceutical Sciences” by E. W. Martin, 18th Edition. The choice of pharmaceutical carrier can be selected with regard to the intended route of administration and standard pharmaceutical practice. The pharmaceutical compositions may comprise as, in addition to, the carrier any suitable binder(s), lubricant(s), suspending agent(s), coating agent(s), and/or solubilizing agent(s).
It will be appreciated that pharmaceutical compositions for use in accordance with the present invention may be in the form of oral, parenteral, transdermal, inhalation, sublingual, topical, implant, nasal, or enterally administered (or other mucosally administered) suspensions, capsules or tablets, which may be formulated in conventional manner using one or more pharmaceutically acceptable carriers or excipients.
There may be different composition/formulation requirements depending on the different delivery systems. Likewise, if the composition comprises more than one active component, then those components may be administered by the same or different routes.
The pharmaceutical formulations of the present invention can be liquids that are suitable for oral, mucosal and/or parenteral administration, for example, drops, syrups, solutions, injectable solutions that are ready for use or are prepared by the dilution of a freeze-dried product but are preferably solid or semisolid as tablets, capsules, granules, powders, pellets, pessaries, suppositories, creams, salves, gels, ointments; or solutions, suspensions, emulsions, or other forms suitable for administration by the transdermal route or by inhalation.
The compounds of the invention can be administered for immediate-, delayed-, modified-, sustained-, pulsed-or controlled-release applications.
In one aspect, oral compositions are slow, delayed or positioned release (e.g., enteric especially colonic release) tablets or capsules. This release profile can be achieved without limitation by use of a coating resistant to conditions within the stomach but releasing the contents in the colon or other portion of the GI tract wherein a lesion or inflammation site has been identified or a delayed release can be achieved by a coating that is simply slow to disintegrate or the two (delayed and positioned release) profiles can be combined in a single formulation by choice of one or more appropriate coatings and other excipients. Such formulations constitute a further feature of the present invention.
Pharmaceutical compositions can be prepared by mixing a therapeutically effective amount of the active substance with a pharmaceutically acceptable carrier that can have different forms, depending on the way of administration. Typically composition components include one or more of binders, fillers, lubricants, odorants, dyes, sweeteners, surfactants, preservatives, stabilizers and antioxidants.
The pharmaceutical compositions of the invention may contain from 0.01 to 99% weight-per volume of the active material. The therapeutic doses will generally be between about 10 and 2000 mg/day and preferably between about 30 and 1500 mg/day. Other ranges may be used, including, for example, 50-500 mg/day, 50-300 mg/day, 100-200 mg/day.
Administration may be once a day, twice a day, or more often, and may be decreased during a maintenance phase of the disease or disorder, e.g. once every second or third day instead of every day or twice a day. The dose and the administration frequency will depend on the clinical signs, which confirm maintenance of the remission phase, with the reduction or absence of at least one or more preferably more than one clinical signs of the acute phase known to the person skilled in the art.
It is within the scope of the invention for a compound as described herein to be administered in combination with another pharmaceutical, e.g. another drug with known efficacy against the disease in question. The compounds of the invention may therefore be used in combination therapy.
The invention will now be further described with reference to the following non limiting examples:
The chemistry described in the following schemes is used to manufacture the compounds described in the tables which follow. The starting materials in each scheme are readily available compounds. In general, molar equivalents of each reactant are employed.
The chemistry described in the following schemes is used to manufacture the compounds described in the tables which follow. The starting materials in each scheme are readily available compounds. In general, molar equivalents of each reactant are employed.
Experimental Procedures for the Formation of Compounds
A. To a solution of thiazole (1.1 mmol) in dry THF (2 mL) under argon atmosphere and at −78° C., n-BuLi solution (1.1 mmol, 2.5 M in hexanes) was added dropwise over a period of 5 min. After stirring at −78° C. for 30 min, a solution of the appropriate aldehyde (1 mmol) in dry THF (2 mL) was added and the mixture was stirred for additional 4 hours at −78° C. Then, H 2 O was added and the mixture was extracted thrice with EtOAc. The organic layer was dried (Na 2 SO 4 ) and concentrated under reduced pressure. Purification by flash eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) afforded the desired product.
B. To a solution of the hydroxy-heterocycle (1 mmol) in dry CH 2 Cl 2 (10 mL), Dess-Martin periodinane was added (1.5 mmol) and the mixture was stirred for 1 h at rt. The organic solution was washed with 10% aqueous NaHCO 3 , dried over Na 2 SO 4 and concentrated under reduced pressure. The residue was purified by column-chromatography using the appropriate mixture of EtOAc: petroleum ether (40-60° C.) as eluent.
C. To a stirred solution of the carboxylic acid (1 mmol) in CH 2 Cl 2 (7 mL), 4-dimethylaminopyridine (DMAP) (1 mmol), N,O-dimethyl hydroxyamine hydrochloride (1 mmol), N-methylmorpholine (1 mmol) and N-(3-dimethylaminopropyl)-N′-ethyl carbodiimide hydrochloride (WSCI.HCl) (1 mmol) were added consecutively at room temperature. The reaction mixture was left stirring for 18 h. It was then washed with an aqueous solution of 10% citric acid (3×10 mL), brine (10 mL), an aqueous solution of NaHCO 3 5% (3×10 mL) and brine (10 mL). The organic layer was dried (Na 2 SO 4 ) and concentrated under reduced pressure. The amide was purified by flash chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) to afford the desired product.
D. To a stirred solution of acid (1 mmol) in dry CH 2 Cl 2 (7 mL), DMF (0.5 eq.) was added followed by oxalyl chloride (3 mmol) at room temperature. The reaction mixture was left stirring for 3 h. The solvent was removed and dry Et 2 O (7 mL) was added and cooled at 0° C. Pyridine (5 mmol) was added drop-wise, followed by drop-wise addition of morpholine (5 mmol). The reaction mixture was left stirring for 18 h at room temperature. Then, H 2 O (8 mL) was added and it was left stirring for 30 min. The layers were separated and the organic layer was washed with an aqueous solution of HCl 1N (3×10 mL), brine (1×10 mL), an aqueous solution of NaHCO 3 5% (3×10 mL) and brine (1×10 mL). The organic layer was dried (Na 2 SO 4 ) and concentrated under reduced pressure. Purification by flash chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) afforded the desired product.
E. To a stirred solution of thiazole or benzothiazole (3 mmol) in dry Et 2 O (20 mL) at −78° C. under a dry argon atmosphere was added a solution of n-BuLi (1.6 M in hexanes, 3 mmol) drop-wise over a period of 10 min. The resulting orange solution was stirred for 45 min. Then, a solution of the amide (1 mmol) in dry Et 2 O (2 mL) was slowly added giving the mixture a dark brown color. After stirring for 30 min. at −78° C., the mixture was allowed to warm up to room temperature over a period of 2 h. Then, saturated aqueous ammonium chloride solution was added and the mixture was extracted with ether (2×10 mL). The combined extracts were washed with brine and then dried over Na 2 SO 4 and concentrated under reduced pressure. Purification by flash chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) afforded the desired product.
F. To a stirred solution of the ester (1 mmol) in dry Et 2 O (10 mL) was added dropwise DIBALH (1.1 mL, 1.0 M in hexane, 1.1 mmol) at 0° C. The reaction was stirred for 10 min and then quenched with H 2 O. The mixture was stirred for 30 min, dried over Na 2 SO 4 , and filtered through a pad of Celite. The solvent was evaporated and the crude product was purified by silica gel column chromatography.
G. To a solution of the alcohol (1 mmol) in a mixture of toluene-EtOAc (6 mL), a solution of NaBr (1.05 mmol) in water (0.5 mL) was added, followed by AcNH-TEMPO (0.01 mmol). To the resulting biphasic system, which was cooled at −5° C., an aqueous solution of 0.35 M NaOCl (3.14 mL, 1.10 mmol) containing NaHCO 3 (3 mmol) was added dropwise while stirring vigorously at −5° C. over a period of 1 h. After the mixture had been stirred for a further 15 min at 0° C., EtOAc (6 mL) and H 2 O (2 mL) were added. The aqueous layer was separated and washed with EtOAc (4 mL). The combined organic layers were washed consecutively with 5% aqueous citric acid (6 mL) containing 5% KI, 10% aqueous Na 2 S 2 O 3 (6 mL), and brine and dried over Na 2 SO 4 . The solvents were evaporated under reduced pressure, and the residue was used immediately in the next step without any purification.
H. A solution of the aldehyde (1 mmol) in CH 2 Cl 2 (2 mL) was added to a mixture of tert-butyl dimethylsilylcyanide (1 mmol), potassium cyanide (0.17 mmol) and 18-crown-6 (0.4 mmol) under argon atmosphere. The mixture was stirred for 1 h. The solvent was evaporated and the crude product was purified by silica gel column chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) to afford the desired product.
I. To a solution of the cyanide (1 mmol) in CH 2 Cl 2 (20 mL) at 0° C. was added 30% H 2 O 2 (0.5 mL), tetrabutyammonium hydrogen sulfate (0.2 mmol) and an aqueous solution of 0.5 N NaOH (1.2 mmol). The reaction mixture was stirred in a sealed flask for 18 h during which additional H 2 O 2 (0.5 mL) were added thrice. H 2 O and CH 2 Cl 2 were added and the organic layer was separated, washed with brine and dried over Na 2 SO 4 . The crude product was purified by silica gel column chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) to afford the desired product.
J. Lawesson's reagent (0.6 mmol) was added to a solution of the amide (1 mmol) in dry toluene (10 mL) under argon atmosphere. The reaction mixture was stirred for 18 h at room temperature. The solvent was evaporated and the crude product was purified by silica gel column chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) to afford the desired product.
K. To a solution of the thioamide (1 mmol) in ethanol (3.2 mL) under argon atmosphere, was added ethyl bromopyruvate or ethyl 4-chloroacetoacetate (1 mmol) and concentrated H 2 SO 4 (10 μL). The reaction mixture was stirred for 18 h. The solvent was evaporated and the crude product was purified by silica gel column chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) to afford the desired product.
L. To a solution of the hydroxyl heterocyclic ester (1 mmol) in EtOH (25 mL), an aqueous solution of 1 N NaOH (20 mmol, 20 mL) was added. After stirring for 1 h, the solution was acidified with aqueous solution of 1N HCl and the product was extracted with Et 2 O. The organic layer was separated, washed with brine and dried over Na 2 SO 4 . The product was used in the next step without any purification.
M. To a solution of the oxo heterocyclic ester (1 mmol) in EtOH (25 mL), an aqueous solution of 20% Cs 2 CO 3 (20 mmol, 20 mL) was added. After stirring for 18 h, the solution was acidified with aqueous solution of 1N HCl and the product was extracted with Et 2 O. The organic layer was separated, washed with brine and dried over Na 2 SO 4 . The product was purified by recrystallization.
N. To a stirred solution of LiAlH 4 (1M in THF, 2.9 mmol) in dry Et 2 O (5.5 mL) under argon atmosphere and at −20° C. a solution of the ester (1 mmol) in dry Et 2 O (5.5 mL) was added. The reaction was stirred for 20 min at −20° C. and for 20 min at rt. Then, it was cooled at 0° C. and quenched with H 2 O. The mixture was stirred for 30 min at rt. Then, additional H 2 O was added and the mixture was acidified with 1 N HCl to pH 5. The aqueous layer was washed twice with Et 2 O, and then the combined organic layers were washed with brine, dried over Na 2 SO 4 , and the solvent was evaporated. The crude product was purified by silica gel column chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) to afford the desired product.
O. To a stirred solution of the alcohol (1 mmol) in acetone (4.2 mL), K 2 CO 3 (3 mmol) was added followed by a catalytic amount of KI and the appropriate bromide (1.1 mmol). The solution was refluxed for 18 h, the solvent was evaporated, and H 2 O and EtOAc were added. The aqueous layer was washed twice with EtOAc and then the combined organic layers were washed with brine, dried over Na 2 SO 4 , and the solvent was evaporated. The crude product was purified by silica gel column chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) to afford the desired product.
P. A solution of the hydroxy compound (1 mmol) in dry CH 2 Cl 2 (50 mL) was treated dropwise with a solution of DAST (3 mmol) in dry CH 2 Cl 2 (2 mL) under argon atmosphere and at −78° C. The reaction mixture was stirred for 2 h at −78° C. and for additional 16 h at rt. Then, a saturated solution of NaHCO 3 was added until the bubbling of CO 2 stopped. The solution was stirred for 20 min and then H 2 O and CH 2 Cl 2 were added. The organic layer was separated, dried over Na 2 SO 4 , filtered and evaporated, and the crude product was purified by column chromatography on silica gel eluting with EtOAc-petroleum ether (bp 40-60° C.) to yield the desired fluoro derivative.
Q. A solution of oxalyl chloride (4 mmol) in dry CH 2 Cl 2 (3 mL) under argon atmosphere and at −60° C. was treated dropwise with a solution of dry DMSO (8 mmol) in dry CH 2 Cl 2 (3.5 mL). After 5 min, a solution of the fluoro alcohol (1 mmol) in dry CH 2 Cl 2 (20 mL) was added dropwise and after additional 15 min, dry Et 3 N (16 mmol) was added. The reaction mixture was stirred for 1 h to reach room temperature. Then, the reaction mixture was poured in ice and the aqueous layer was extracted thrice with CH 2 Cl 2 . The combined organic layers were washed with brine, dried over Na 2 SO 4 , and the solvent was evaporated. The crude product was purified by silica gel column chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) to afford the desired product.
R. A solution of the aldehyde (1 mmol) and methyl (triphenylphosphanylidene)acetate (1.1 mmol) in dry CH 2 Cl 2 (3 mL) under argon atmosphere was refluxed for 1 h and then left stirring for 16 h at rt. Saturated solution of NH 4 Cl was added and the aqueous layer was extracted thrice with CH 2 Cl 2 . The combined organic layers were washed with brine, dried over Na 2 SO 4 , and the solvent was evaporated. The crude product was purified by silica gel column chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) to afford the desired product.
S. A mixture of the unsaturated ester (1 mmol) in dry 1,4-dioxane (10 mL) and a catalytic amount of 10% palladium on activated carbon was hydrogenated for 18 h. After filtration through a pad of celite and the solvent was removed in vacuo. The crude product was purified by silica gel column chromatography eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.) to afford the desired product.
T. A solution of the aldehyde (1 mmol) and NaHSO 3 (1.5 mmol in 1.3 mL H 2 O) in CH 2 Cl 2 (1.2 mL) was stirred for 30 min at room temperature. After the formation of a white salt, the organic solvent was evaporated and water (1 mL) was added. The mixture was cooled to 0° C. and an aqueous solution of KCN (1.5 mmol in 1.3 mL H 2 O) was added dropwise. The reaction mixture was stirred for another 18 h at room temperature and then CH 2 Cl 2 and water were added. The organic layer was washed with brine and dried (Na 2 SO 4 ). The solvent was evaporated under reduced pressure and the residual oil was purified by column chromatography on silica gel eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.).
U. The cyanhydrine (1 mmol) was treated with 6N HCl (10 mL) in MeOH for 18 h at room temperature. The organic solvent was evaporated and a saturated aqueous solution of K 2 CO 3 was added to pH neutralization. After extraction with CH 2 Cl 2 (3×15 mL), the combined organic phases were washed with brine and dried (Na 2 SO 4 ). The solvent was evaporated under reduced pressure and the residual oil was purified by column chromatography on silica gel eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.).
V. To a stirred solution of the Z-protected amino compound (1 mmol) in MeOH (8 mL) were added successively a catalytic amount of 10% Pd/C and anhydrous ammonium formate (5 mmol). After stirring for 2 h at rt, the reaction mixture was filtered over celite. The organic layer was then concentrated under reduced pressure to yield the crude product, which was used without any further purification.
W. To a stirred solution of phenylacetic acid (1.0 mmol) and the amino component (1.0 mmol) in dry CH 2 Cl 2 (10 mL), Et 3 N (1.1 mmol) and subsequently 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide (WSCI) (1.1 mmol) and 1-hydroxybenzotriazole (HOBt) (1.0 mmol) were added at 0° C. The reaction mixture was stirred for 1 h at 0° C. and overnight at rt. The solvent was evaporated under reduced pressure and EtOAc (20 mL) was added. The organic layer was washed consecutively with brine, 1N HCl, brine, 5% NaHCO 3 , and brine, dried over Na 2 SO 4 and evaporated under reduced pressure. The residue was purified by column chromatography on silica gel eluting with the appropriate mixture of EtOAc: petroleum ether (40-60° C.).
X. A solution of the tert-butyl ester derivative (1 mmol) in 50% TFA/CH 2 Cl 2 (10 mL) was stirred for 1 h at room temperature. The organic solvent was evaporated under reduced pressure to afford the desired product.
Compounds 1-3
Characterising Data
1-(Thiazol-2-yl)hexadecan-1-ol (2a)
Procedure A
White solid. Yield 51%.
m.p. 69-71° C.
1 H NMR: δ 7.68 (d, 1H, J=2.8 Hz, ArH), 7.25 (d, 1H, J=2.8 Hz, ArH), 4.97 (m, 1H, CHOH), 3.14 (br s, 1H, OH), 1.86 (m, 2H, CH 2 CHOH), 1.48-1.13 (m, 26H, 13×CH 2 ), 0.86 (t, 3H, J=6.2 Hz, CH 3 ).
13 C NMR: δ 175.6, 142.0, 118.8, 71.8, 38.3, 31.9, 29.7, 29.6, 29.6, 29.5, 29.4, 29.3, 25.2, 22.7, 14.1.
5-Phenyl-1-(thiazol-2-yl)pentan-1-ol (2b)
Procedure A
Colorless Oil. Yield 42%.
1 H NMR: δ 7.65 (d, 1H, J=3.4 Hz, ArH), 7.33-7.16 (m, 6H, Ph, ArH), 4.97 (m, 1H, CHOH), 4.5 (br, 1H, OH), 2.62 (t, 2H, J=7.0 Hz, CH 2 Ph), 2.05-1.80 (m, 2H, CH 2 CHOH), 1.74-1.45 (m, 4H, 2×CH 2 ).
13 C NMR: δ 176.3, 142.3, 141.8, 128.3, 128.2, 125.6, 118.7, 71.4, 37.9, 35.7, 31.1, 24.9.
(Z)-1-(Thiazol-2-yl)octadec-9-en-1-ol (2c)
Procedure A
C 21 H 37 NOS
White oil.
1 H NMR (CDCl 3 ) δ: 7.69 (d, 1H, J=3.4 Hz, CHN), 7.28 (d, 1H, J=3.4 Hz, CHS), 5.34 (m, 2H, CH═CH), 4.97 (dd, 1H, J 1 =7.4 Hz, J 2 =5.2 Hz, CHOH), 3.47 (b, 1H, OH), 2.00 (m, 6H, 3×CH 2 ), 1.60-1.10 (m, 22H, 11×CH 2 ), 0.88 (t, 3H, J=6.2 Hz, CH 3 ).
13 C NMR (CDCl 3 ) δ: 175.7, 142.0, 129.9, 129.8, 118.7, 71.8, 38.3, 31.9, 29.7, 29.5, 29.3, 29.2, 27.1, 25.2, 22.6, 14.1.
(5Z,8Z,11Z,14Z)-1-(Thiazol-2-yl)icosa-5,8,11,14-tetraen-1-ol (2d)
Procedure A
C 23 H 35 NOS
MW: 373.60.
White oil.
1 H NMR (CDCl 3 ) δ: 7.64 (d, 1H, J=3.0 Hz, ArH), 7.23 (d, 1H, J=3.0 Hz, ArH), 5.56-5.21 (m, 8H, 4×CH═CH), 4.96 (dd, 1H, J 1 =6.8 Hz, J 2 =5.0 Hz, CHOH), 4.20-3.90 (br, 1H, OH), 2.98-2.63 (m, 6H, 3×CHCH 2 CH), 2.18-1.79 (m, 6H, 3×CH 2 ), 1.69-1.18 (m, 8H, 4×CH 2 ), 0.90 (t, 3H, J=6.6 Hz, CH 3 ).
13 C NMR (CDCl 3 ) δ: 175.8, 141.9, 130.4, 129.5, 128.5, 128.2, 128.0, 127.9, 127.8, 127.5, 118.7, 71.5, 37.7, 31.4, 29.2, 27.1, 26.8, 25.5, 25.4, 25.1, 22.5, 14.0.
MS (ESI) m/z (%): 373 [M + , 100].
1-(Thiazol-2-yl)hexadecan-1-one (3a)
Procedure B
C 19 H 33 NOS
MW: 323.54.
White solid.
m.p.: 39-41° C.
1 H NMR (200 MHz, CDCl 3 ) δ=7.98 (d, 1H, J=3.0 Hz, ArH), 7.65 (d, 1H, J=3.0 Hz, ArH), 3.14 (t, 2H, J=7.4 Hz, CH 2 CO), 1.81-1.68 (m, 2H, CH 2 CH 2 CO), 1.42-1.10 (m, 24H, 12×CH 2 ), 0.86 (t, 3H, J=5.0 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=194.1, 167.3, 144.6, 126.0, 38.5, 31.9, 29.6, 29.4, 29.3, 29.2, 24.0, 22.7, 14.1.
MS (ESI) m/z (%): 324 [M+H, 100] + .
5-Phenyl-1-(thiazol-2-yl)pentan-1-one (3b)
Procedure B
C 14 H 15 NOS
MW: 245.34.
Yellow oil.
1 H NMR (200 MHz, CDCl 3 ) δ=8.00 (d, 1H, J=3.0 Hz, ArH), 7.66 (d, 1H, J=2.8 Hz, ArH), 7.33-7.13 (m, 5H, Ph), 3.21 (t, 2H, J=6.6 Hz, CH 2 CO), 2.68 (t, 2H, J=7.6 Hz, PhCH 2 ), 1.92-1.65 (m, 4H, 2×CH 2 ).
13 C NMR (50 MHz, CDCl 3 ) δ=193.8, 167.1, 144.5, 142.0, 128.3, 128.2, 126.1, 125.6, 38.2, 35.6, 30.9, 23.6.
(Z)-1-(Thiazol-2-yl)octadec-9-en-1-one (3c)
Procedure B
C 21 H 35 NOS
Yellowish oil.
1 H NMR (CDCl 3 ) δ: 8.00 (d, 1H, J=3.0 Hz, CHN), 7.66 (d, 1H, J=3.0 Hz, CHS), 5.34 (m, 2H, CH═CH), 3.16 (t, 2H, J=8.0 Hz, CH 2 CO), 2.01 (m, 4H, 2×CH 2 CH═), 1.80-1.60 (m, 2H, CH 2 ), 1.60-1.10 (m, 20H, 10×CH 2 ), 0.88 (t, 3H, J=6.2 Hz, CH 3 ). 13 C NMR (CDCl 3 ) δ: 194.1, 167.4, 144.6, 130.0, 129.7, 126.0, 38.5, 32.6, 31.9, 29.7, 29.5, 29.3, 29.2, 29.1, 27.2, 24.0, 22.7, 14.1.
(5Z,8Z,11Z,14Z)-1-(Thiazol-2-yl)icosa-5,8,11,14-tetraen-1-one (3d)
Procedure B
C 23 H 33 NOS
Yellowish oil.
1 H NMR (CDCl 3 ) δ: 8.00 (d, 1H, J=2.8 Hz, ArH), 7.66 (d, 1H, J=2.8 Hz, ArH), 5.42-5.21 (m, 8H, 4×CH═CH), 3.19 (t, 2H, J=7.2 Hz, CH 2 CO), 2.88-2.63 (m, 6H, 3×CHCH 2 CH), 2.25-2.20 (m, 4H, 2×CH 2 ), 1.45-1.17 (m, 2H, CH 2 ), 1.40-1.20 (m, 6H, 3×CH 2 ), 0.88 (t, 3H, J=6.4 Hz, CH 3 ).
13 C NMR (CDCl 3 ) δ: 193.9, 167.2, 144.6, 130.4, 129.1, 128.9, 128.5, 128.2, 128.1, 127.9, 127.5, 126.1, 37.8, 31.5, 29.3, 29.2, 27.2, 26.6, 25.6, 23.9, 22.5, 14.0.
Compounds 3 to 5 (Alternative Strategies)
N-Methoxy-N-methyl-palmitamide (4a)
Procedure C
C 18 H 37 NO 2
MW: 299.49.
colorless oil. Yield 81%.
1 H NMR (200 MHz, CDCl 3 ) δ=3.66 (s, 3H, OMe), 3.16 (s, 3H, NMe), 2.39 (t, 2H, J=7.6 Hz, CH 2 CO), 1.70-1.57 (m, 2H, CH 2 CH 2 CO), 1.23-1.08 (m, 24H, 12×CH 2 ), 0.86 (t, 3H, J=3.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=174.6, 61.0, 31.8, 29.5, 29.4, 29.3, 24.8, 24.5, 22.5, 13.9. MS (ESI) m/z (%): 300 [M+H, 100] + .
N-Methoxy-N-methyl-5-phenylpentanamide (4b) (by the Weinreb method)
Procedure C
C 13 H 19 NO 2
MW: 221.30.
Colorless oil. Yield 81%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.33-7.12 (m, 5H, Ph), 3.65 (s, 3H, OMe), 3.17 (s, 3H, NMe), 2.65 (t, 2H, J=7.2 Hz, PhCH 2 ), 2.44 (t, 2H, J=7.2 Hz, CH 2 CO), 1.72-1.66 (m, 4H, 2×CH 2 ).
13 C NMR (50 MHz, CDCl 3 ) δ=174.6, 142.2, 128.2, 128.1, 125.6, 61.0, 35.6, 31.6, 31.1, 24.2.
MS (ESI) m/z (%): 222 [M+H, 100] + .
General Procedure for the Synthesis of Morpholine Amides
To a stirred solution of acid (1 eq.) in dry CH 2 Cl 2 (7 mL), DMF (0.5 eq.) was added followed by oxalyl chloride (3 eq.) at room temperature. The reaction mixture was left stirring for 3 h. The solvent was removed and dry Et 2 O (7 mL) was added and cooled at 0° C. Pyridine (5 eq.) was added drop-wise, followed by drop-wise adittion of morpholine (5 eq.). The reaction mixture was left stirring for 18 h at room temperature. Then, H 2 O (8 mL) was added and it was left stirring for 30 min. The layers were separated and the organic layer was washed with an aqueous solution of HCl 1N (3×10 mL), brine (1×10 mL), an aqueous solution of NaHCO 3 5% (3×10 mL) and brine (1×10 mL). The organic layer was dried (Na 2 SO 4 ) and concentrated under reduced pressure. Purification by flash chromatography eluting with the appropriate mixture of EtOAc: pet. ether (40-60° C.) afforded the desired product.
1-Morpholinohexadecan-1-one (5a)
Procedure D
C 20 H 39 NO 2
MW: 325.53.
White solid. Yield 99%.
m.p.: 45-46° C.
1 H NMR (200 MHz, CDCl 3 ) δ=3.66-3.60 (m, 6H, CH 2 OCH 2 , CHHNCHH), 3.43-3.38 (m, 2H, CHHNCHH), 2.28 (t, 2H, J=7.2 Hz, CH 2 CO), 1.63-1.52 (m, 2H, CH 2 CH 2 CO), 1.34-1.06 (m, 24H, 12×CH 2 ), 0.85 (t, 3H, J=5.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=171.8, 66.8, 66.6, 45.9, 41.7, 33.0, 31.8, 29.6, 29.5, 29.4, 29.3, 29.2, 25.2, 22.6, 14.0.
MS (ESI) m/z (%): 326 [M+H, 100] + .
1-Morpholino-5-phenylpentan-1-one (5b)
Procedure D
C 15 H 21 NO 2
MW: 247.33.
Colorless oil. Yield 74% (1.025 g).
1 H NMR (200 MHz, CDCl 3 ) δ=7.26-7.09 (m, 5H, Ph), 3.64-3.42 (m, 6H, CH 2 OCH 2 , CHHNCHH), 3.41-3.23 (m, 2H, CHHNCHH), 2.61 (t, 2H, J=7.0 Hz, PhCH 2 ), 2.27 (t, 2H, J=7.2 Hz, CH 2 CO), 1.69-1.60 (m, 4H, 2×CH 2 ).
13 C NMR (50 MHz, CDCl 3 ) δ=171.3, 141.9, 128.2, 128.1, 125.5, 66.7, 66.4, 45.7, 41.6, 35.5, 32.7, 30.9, 24.6.
MS (ESI) m/z (%): 248 [M+H, 100] + , 270 [M+23, 23].
Synthesis of 2-oxo-thiazoles Using the Weinreb and Morpholino Amide Method
To a stirred solution of thiazole (3 eq.) in dry Et 2 O (20 mL) at −78° C. under a dry argon atmosphere was added a solution of n-BuLi (1.6 M in hexanes, 3 eq.) drop-wise over a period of 10 min. The resulting orange solution was stirred for 45 min. Then a solution of the amide (1 eq.) in dry Et 2 O (2 mL) was slowly added giving the mixture a dark brown color. After stirring for 30 min. at −78° C., the mixture was allowed to warm up to room temperature over a period of 2 h. Then, saturated aqueous ammonium chloride solution was added and the mixture was extracted with ether (2×10 mL). The combined extracts were washed with brine and then dried over Na 2 SO 4 and concentrated under reduced pressure. Purification by flash chromatography eluting with the appropriate mixture of EtOAc: pet. ether (40-60° C.) afforded the desired product.
1-(Thiazol-2-yl)hexadecan-1-one (3a)
Procedure E
Yield when the Weinreb amide was used: 73%.
Yield when the morpholine amide was used: 98%.
5-Phenyl-1-(thiazol-2-yl)pentan-1-one (3b)
Procedure E
Yield when the Weinreb amide was used: 85%.
Yield when the morpholine amide was used: 86%.
Compounds 6 to 9
3-(4-(Hexyloxy)phenyl)propanal (7)
Procedure F then G
C 15 H 22 O 2
MW: 234.33
Orange oil. Yield 64%.
1 H NMR (200 MHz, CDCl 3 ) δ=9.80 (s, 1H, CHO), 7.09 (d, 2H, J=8.4 Hz, CH), 6.82 (d, 2H, J=8.6 Hz, 2×CH), 3.92 (t, 2H, J=6.4 Hz, CH 2 ), 3.00-2.85 (m, 2H, CH 2 ), 2.80-2.65 (m, 2H, CH 2 ), 1.85-1.65 (m, 2H, CH 2 ), 1.50-1.20 (m, 6H, 3×CH 2 ), 0.92 (m, 3H, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=201.7, 157.6, 132.0, 129.1, 114.5, 67.9, 45.5, 31.5, 29.2, 27.2, 25.7, 22.5, 14.0
3-(4-(Hexyloxy)phenyl)-1-(thiazol-2-yl)propan-1-ol (8)
Procedure A
C 18 H 25 NO 2 S
MW: 319.46
Colorless oil. Yield 66%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.65 (d, 1H, J=3.2 Hz, ArH), 7.24 (d, 1H, J=3.4 Hz, ArH), 7.07 (d, 2H, J=8.8 Hz, 2×CH), 6.79 (d, 2H, J=8.6 Hz, 2×CH), 4.96 (dd, 1H, J=7.6 Hz, J 2 =5.0 Hz, CH), 3.90 (t, 2H, J=6.4 Hz, CH 2 O), 2.80-2.60 (m, 2H, CH 2 ), 2.25-2.05 (m, 2H, CH 2 ), 1.85-1.65 (m, 2H, CH 2 ), 1.50-1.30 (m, 6H, 3×CH 2 ), 0.88 (t, 3H, J=6.2 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=175.9, 157.4, 142.0, 133.0, 129.3, 118.8, 114.4, 70.9, 67.9, 39.9, 31.5, 30.5, 29.2, 25.6, 22.5, 14.0.
3-(4-(Hexyloxy)phenyl)-1-(thiazol-2-yl)propan-1-one (9)
Procedure B
C 18 H 23 NO 2 S
MW: 317.45
Yellowish oil. Yield 78%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.95 (d, 1H, J=3.2 Hz, ArH), 7.62 (d, 1H, J=3.4 Hz, ArH), 7.15 (d, 2H, J=8.8 Hz, CH), 6.81 (d, 2H, J=8.4 Hz, CH), 3.90 (t, 2H, J=6.6 Hz, CH 2 O), 3.45 (t, 2H, J=7.2 Hz, CH 2 ), 3.01 (t, 2H, J=3.8 Hz, CH 2 ), 1.90-1.64 (m, 2H, CH 2 ), 1.58-1.20 (m, 6H, 3×CH 2 ), 0.89 (t, 3H, J=6.6 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=193.1, 167.1, 157.5, 144.6, 132.5, 129.3, 126.1, 114.5, 68.0, 40.3, 31.5, 29.2, 28.9, 25.7, 22.6, 14.0.
MS (ESI) m/z (%): 318 [M+H, 100] + .
Compounds 10 to 15
2-(tert-Butyldimethylsilyloxy)heptadecanenitrile (11a)
Procedure H
C 23 H 47 NOSi
MW: 381.71
Colorless oil. Yield 85%.
1 H NMR (200 MHz, CDCl 3 ) δ=4.41 (t, 1H, J=6.4 Hz, CH), 1.70-1.90 (m, 2H, CH 2 ), 1.40-1.55 (m, 2H, CH 2 ), 1.30-1.15 (m, 24H, 12×CH 2 ), 1.03-0.82 (m, 12H, 4×CH 3 ), 0.19 (s, 3H, CH 3 ), 0.14 (s, 3H, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=120.1, 61.9, 36.3, 31.9, 29.6, 29.5, 29.4, 29.3, 28.9, 25.5, 24.5, 22.7, 18.0, 14.1, −5.2, −5.4.
2-(tert-Butyldimethylsilyloxy)-6-phenylhexanenitrile (11b)
Procedure H
C 18 H 29 NOSi
MW: 303.51
Colorless oil. Yield 82%.
1 H NMR (CDCl 3 ): δ=7.34-7.20 (m, 5H, Ph), 4.44 (t, 1H, J=6.6 Hz, CH), 2.68 (t, 2H, J=7.4 Hz, 1.88-1.80 (m, 2H, CH 2 ), 1.76-1.69 (m, 2H, CH 2 ), 1.68-1.58 (m, 2H, CH 2 ), 0.97 (s, 9H, 3×CH 3 ), 0.23 (s, 3H, CH 3 ), 0.18 (s, 3H, CH 3 ).
13 C NMR (CDCl 3 ) δ=142.0, 128.3, 128.0, 125.8, 120.1, 61.8, 36.1, 35.6, 30.8, 25.7, 25.5, 24.1, 18.0, −5.2, −5.4.
2-(tert-Butyldimethylsilyloxy)heptadecanamide (12a)
Procedure I
C 23 H 49 NO 2 Si
MW: 399.73
Yellow oil. Yield 63%.
1 H NMR (200 MHz, CDCl 3 ) δ=6.49 (s, 1H, NHH), 6.14 (s, 1H, NHH), 4.10 (t, 1H, J=5.0 Hz, CH), 1.80-1.56 (m, 2H, CH 2 ), 1.40-1.10 (m, 26H, 13×CH 2 ), 0.95-0.80 (m, 12H, 4×CH 3 ), 0.17 (s, 3H, CH 3 ), 0.14 (s, 3H, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ 177.3, 73.4, 35.1, 31.9, 29.7, 29.6, 29.5, 29.4, 29.3, 25.7, 24.1, 22.7, 18.0, 14.1, −4.9, −5.3.
MS (ESI) m/z (%) δ=400 [M+H, 40] + , 422 [M+Na, 100] + .
2-(tert-Butyldimethylsilyloxy)-6-phenylhexanamide (12b)
Procedure I
C 18 H 31 NO 2 Si
MW: 321.53
Colorless oil. Yield 100%.
1 H NMR (CDCl 3 ): δ=7.28-7.15 (m, 5H, Ph), 6.51 (s, 1H, NH), 5.61 (s, 1H, NH), 4.16 (t, 1H, J=6.6 Hz, CH), 2.62 (t, 2H, J=7.4 Hz, CH 2 ), 1.77-1.32 (m, 6H, 3×CH 2 ), 0.91 (s, 9H, 3×CH 3 ), 0.06 (s, 6H, 2×CH 3 ).
13 C NMR (CDCl 3 ): δ=177.4, 142.3, 128.2, 128.1, 125.5, 73.2, 35.6, 34.8, 31.2, 25.6, 23.8, 17.8, −5.0, −5.4.
MS (ESI) m/z (%): 322 [M+H, 100] + .
2-(tert-Butyldimethylsilyloxy)heptadecanethioamide (13a)
Procedure J
C 23 H 49 NOSSi
MW: 415.79
Yellowish oil. Yield 84%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.96 (s, 1H, NHH), 7.74 (s, 1H, NHH), 4.56 (t, 1H, J=5.0 Hz, CH), 1.90-1.70 (m, 2H, CH 2 ), 1.47-1.15 (m, 26H, 13×CH 2 ), 1.00-0.83 (m, 12H, 4×CH 3 ), 0.12 (s, 3H, CH 3 ), 0.09 (s, 3H, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=210.3, 80.1, 38.0, 32.1, 29.9, 29.8, 29.7, 29.6, 26.0, 25.7, 24.1, 22.9, 18.3, 14.3, −4.7, −4.9.
MS (ESI) m/z (%): 416 [M+H, 90] + .
2-(tert-Butyldimethylsilyloxy)-6-phenylhexanethioamide (13b)
Procedure J
C 18 H 31 NOSSi
MW: 337.60
Yellowish oil. Yield 64%.
1 H NMR (CDCl 3 ): δ=8.28 (s, 1H, NH), 7.98 (s, 1H, NH), 7.24-7.10 (m, 5H, Ph), 4.52 (t, 1H, J=6.6 Hz, CH), 2.57 (t, 2H, J=7.4 Hz, CH 2 ), 1.95-1.80 (m, 2H, CH 2 ), 1.62-1.45 (m, 2H, CH 2 ), 1.42-1.25 (m, 2H, CH 2 ), 0.88 (s, 9H, 3×CH 3 ), 0.06 (s, 3H, SiCH 3 ), 0.04 (s, 3H, SiCH 3 ).
13 C NMR (CDCl 3 ): 209.6, 142.3, 128.3, 128.1, 125.5, 79.6, 37.4, 35.6, 31.2, 25.6, 23.5, 17.9, −5.1, −5.3.
MS (ESI) m/z (%): 338 [M+H, 100] + .
Ethyl 2-(1-hydroxyhexadecyl)thiazole-4-carboxylate (14a)
Procedure K
C 22 H 39 NO 3 S
MW: 397.61
Yellowish solid. Yield 74%.
1 H NMR (200 MHz, CDCl 3 ) δ=8.06 (s, 1H, CH), 5.03 (dd, 1H, J 1 =4.5 Hz, J 2 =8.1 Hz, CH), 4.36 (q, 2H, J=7.1 Hz, CH 2 ), 3.10-2.90 (br, 1H, OH), 2.00-1.60 (m, 2H, CH 2 ), 1.35 (t, 3H, J=7.1 Hz, CH 3 ), 1.40-1.10 (m, 26H, 13×CH 2 ), 0.85 (t, 3H, J=6.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=177.3, 161.4, 146.6, 127.1, 71.8, 61.3, 38.1, 31.8, 29.6, 29.5, 29.4, 29.3, 29.2, 25.5, 25.1, 22.6, 14.2, 14.0.
Ethyl 2-(1-hydroxy-5-phenylpentyl)thiazole-4-carboxylate (14b)
Procedure K
C 17 H 21 NO 3 S
MW: 319.42
Yellowish oil. Yield 45%.
1 H NMR (CDCl 3 ): δ=8.03 (s, 1H, ArH), 7.25-7.10 (m, 5H, Ph), 5.11-5.00 (m, 1H, CH), 4.33 (q, 2H, J=5.8 Hz, OCH 2 ), 4.10-3.95 (m, 1H, OH), 2.56 (t, 2H, J=7.0 Hz, CH 2 ), 1.85-1.78 (m, 2H, CH 2 ), 1.62-1.41 (m, 2H, CH 2 ), 1.32 (t, 3H, J=5.8 Hz, CH 3 ), 1.24-1.20 (m, 2H, CH 2 ).
13 C NMR (CDCl 3 ): δ=177.4, 161.3, 146.4, 142.2, 128.2, 128.1, 127.2, 125.5, 71.5, 61.3, 37.8, 35.5, 30.9, 24.7, 14.2.
Ethyl 2-palmitoylthiazole-4-carboxylate (15a)
Procedure B
C 22 H 37 NO 3 S
MW: 395.60
White solid. Yield 82%.
1 H NMR (200 MHz, CDCl 3 ): δ=8.41 (s, 1H, CH), 4.46 (q, 2H, J=6.8 Hz, CH 2 ), 3.23 (t, 2H, J=7.4 Hz, CH 2 ), 1.85-1.60 (m, 4H, 2×CH 2 ), 1.43 (t, 3H, J=6.8 Hz, CH 3 ), 1.42-1.00 (m, 22H, 11×CH 2 ), 0.88 (t, 3H, J=6.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ): δ=194.3, 167.9, 161.1, 148.9, 133.2, 62.0, 38.6, 32.1, 29.9-29.8, 29.7, 29.6, 29.5, 29.3, 23.8, 22.9, 14.5, 14.3.
MS (ESI) m/z (%): 418 [M+Na, 100] + .
Ethyl 2-(5-phenylpentanoyl)thiazole-4-carboxylate (15b)
Procedure B
C 17 H 19 NO 3 S
MW: 317.40
Yellowish oil. Yield 81%
1 H NMR (CDCl 3 ): δ=8.38 (s, 1H, ArH), 7.24-7.13 (m, 5H, Ph), 4.42 (q, 2H, J=5.8 Hz, OCH 2 ), 3.23 (t, 2H, J=5.8 Hz, CH 2 ), 2.63 (t, 2H, J=7.0 Hz, CH 2 CO), 1.81-1.65 (m, 4H, 2×CH 2 ), 1.39 (t, 3H, J=5.8 Hz, CH 3 ).
13 C NMR (CDCl 3 ): 193.8, 167.4, 160.8, 148.6, 142.0, 133.1, 128.3, 128.2, 125.7, 61.8, 38.1, 35.6, 30.7, 23.2, 14.3.
MS (ESI) m/z (%): 318 [M+H, 100] + .
Compounds 16 to 19
5-(4-(Hexyloxy)phenyl)pentanal (17)
Procedure N then G
C 17 H 26 O 2
MW: 262.39.
Yellowish oil. Yield 97%.
1 H NMR (200 MHz, CDCl 3 ) δ=9.73 (t, 1H, J=1.8 Hz, CHO), 7.06 (d, 2H, J=8.6 Hz, CH, Ph), 6.81 (d, 2H, J=8.6 Hz, CH, Ph), 3.92 (t, 2H, J=6.4 Hz, CH 2 OPh), 2.56 (t, 2H, J=7.0 Hz, PhCH 2 ), 2.47-2.35 (m, 2H, CH 2 CHO), 1.81-1.67 (m, 2H, CH 2 CH 2 OPh), 1.65-1.57 (m, 4H, 2×CH 2 ), 1.55-1.09 (m, 6H, 3×CH 2 ), 0.90 (t, 3H, J=6.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=202.3, 157.2, 133.6, 129.0, 114.2, 67.8, 43.6, 34.6, 31.5, 31.0, 29.2, 25.6, 22.5, 21.5, 20.8, 13.9.
5-(4-(Hexyloxy)phenyl)-1-(thiazol-2-yl)pentan-1-ol (18)
Procedure A
C 20 H 29 NO 2 S
MW: 347.51.
Orange oil. Yield 74%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.62 (d, 1H, J=3.2 Hz, ArH), 7.22 (d, 1H, J=3.4 Hz, ArH), 7.03 (d, 2H, J=8.8 Hz, CH, Ph), 6.77 (d, 2H, J=8.6 Hz, CH, Ph), 4.98-4.84 (m, 1H, CHOH), 4.46 (d, 1H, J=5 Hz, CHOH), 3.89 (t, 2H, J=6.4 Hz, CH 2 OPh), 2.52 (t, 2H, J=7 Hz, PhCH 2 ), 2.48-1.19 (m, 14H, 7×CH 2 ), 0.88 (t, 3H, J=6.6 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=176.3, 157.0, 141.9, 134.2, 129.0, 118.5, 114.1, 71.5, 67.8, 38.0, 34.7, 31.5, 31.3, 29.2, 25.6, 24.7, 22.5, 20.9, 14.0.
MS (ESI) m/z (%): 348 [M+H, 100] + .
5-(4-(Hexyloxy)phenyl)-1-(thiazol-2-yl)pentan-1-one (19)
Procedure G
C 20 H 27 NO 2 S
MW: 345.50.
Yellowish oil. Yield 89%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.98 (d, 1H, J=3.2 Hz, ArH), 7.65 (d, 1H, J=3.4 Hz, ArH), 7.08 (d, 2H, J=8.8 Hz, CH, Ph), 6.81 (d, 2H, J=8.4 Hz, CH, Ph), 3.91 (t, 2H, J=6.6 Hz, CH 2 OPh), 3.18 (t, 2H, J=6.8 Hz, CH 2 CO), 2.60 (t, 2H, J=7.6 Hz, PhCH 2 ), 1.89-1.61 (m, 6H, 3×CH 2 ), 1.48-1.28 (m, 6H, 3×CH 2 ), 0.90 (t, 3H, J=6.6 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=193.7, 167.1, 157.2, 144.5, 133.9, 129.1, 126.1, 114.2, 67.8, 38.2, 34.6, 31.5, 31.1, 29.2, 25.6, 23.5, 22.5, 14.0.
MS (ESI) m/z (%): 346 [M+H, 100] +
Compounds 20 to 24
Ethyl 4-(4-octylphenoxy)butanoate (21)
Procedure O
C 20 H 32 O 3
MW: 320.47.
Colorless oil. Yield 100%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.08 (d, 2H, J=7.8 Hz, CH, Ph), 6.81 (d, 2H, J=7.6 Hz, CH, Ph), 4.15 (q, 2H, J=7.0 Hz, COOCH 2 ), 3.99 (t, 2H, J=5.8 Hz, PhOCH 2 ), 2.58-2.42 (m, 4H, 2×CH 2 ), 2.17-2.06 (m, 2H, CH 2 CH 2 COO), 1.57-1.45 (m, 2H, CH 2 CH 2 Ph), 1.27 (br, 13H, 5×CH 2 , CH 3 ), 0.89 (t, 3H, J=5.2 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=173.2, 156.8, 135.0, 129.1, 114.2, 66.6, 60.3, 35.0, 31.7, 30.8, 29.4, 29.2, 24.6, 22.6, 14.1, 14.0.
MS (ESI) m/z (%): 321 [M+H, 100] + .
4-(4-Octylphenoxy)butanal (22)
Procedure N then G
C 18 H 28 O 2
MW: 276.41.
Colorless oil. Yield 97%.
1 H NMR (200 MHz, CDCl 3 ) δ=9.84 (t, 1H, J=1.4 Hz, CHO), 7.09 (d, 2H, J=8.6 Hz, CH, Ph), 6.81 (d, 2H, J=8.8 Hz, CH, Ph), 3.99 (t, 2H, J=6.0 Hz, PhOCH 2 ), 2.70-2.52 (m, 4H, 2×CH 2 ), 1.63-1.52 (m, 2H, CH 2 CH 2 Ph), 1.31-1.24 (br, 10H, 5×CH 2 ), 0.90 (t, 3H, J=6.4 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=201.7, 156.6, 135.2, 129.2, 114.1, 66.6, 40.6, 35.0, 31.8, 31.7, 29.4, 29.2, 22.6, 22.0, 14.0.
4-(4-Octylphenoxy)-1-(thiazol-2-yl)butan-1-ol (23)
Procedure A
C 21 H 31 NO 2 S
MW: 361.54.
Orange oil. Yield 73%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.72 (d, 1H, J=3.2 Hz, ArH), 7.29 (d, 1H, J=3.2 Hz, ArH), 7.08 (d, 2H, J=8.8 Hz, CH, Ph), 6.81 (d, 2H, J=8.6 Hz, CH, Ph), 5.11 (dd, 1H, J 1 =4.4 Hz, J 2 =7.6 Hz, CHOH), 4.00 (t, 2H, J=6.0 Hz, PhOCH 2 ), 3.92 (s, 1H, OH), 2.54 (t, 2H, J=7.2 Hz, CH 2 Ph), 2.32-1.90 (m, 4H, 2×CH 2 ), 1.67-1.48 (m, 2H, CH 2 CH 2 Ph), 1.30-1.23 (br, 10H, 5×CH 2 ), 0.88 (t, 3H, J=6.2 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=175.4, 156.6, 142.0, 135.3, 129.2, 118.9, 114.3, 71.5, 67.7, 35.1, 35.0, 31.9, 31.7, 29.5, 29.2, 25.2, 22.6, 14.1.
MS (ESI) m/z (%): 362 [M+H, 100] + .
4-(4-Octylphenoxy)-1-(thiazol-2-yl)butan-1-one (24)
Procedure G
C 21 H 29 NO 2 S
MW: 359.53.
Yellowish oil. Yield 85%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.99 (d, 1H, J=3.0 Hz, ArH), 7.65 (d, 1H, J=3.0 Hz, ArH), 7.07 (d, 2H, J=8.6 Hz, CH, Ph), 6.80 (d, 2H, J=8.8 Hz, CH, Ph), 4.06 (t, 2H, J=6.2 Hz, PhOCH 2 ), 3.39 (t, 2H, J=7.2 Hz, CH 2 C═O), 2.54 (t, 2H, J=7.4 Hz, CH 2 Ph), 2.26 (quintet, 2H, J=6.2 Hz, CH 2 CH 2 C═O), 1.68-1.45 (m, 2H, CH 2 CH 2 Ph), 1.30-1.23 (br, 10H, 5×CH 2 ), 0.89 (t, 3H, J=6.2 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=193.2, 166.9, 156.7, 144.6, 135.0, 129.1, 126.0, 114.2, 66.7, 35.1, 35.0, 31.8, 31.7, 29.4, 29.2, 23.6, 22.6, 14.0.
MS (ESI) m/z (%): 360 [M+H, 100] + .
Compounds 25 to 29
Methyl 2-fluorohexadecanoate (26)
Procedure P
C 17 H 33 FO 2
MW: 288.44.
White solid. Yield 78%.
m.p.: 36-38° C.
1 H NMR (200 MHz, CDCl 3 ) δ=4.91 (dt, 1H, J H-H =6.0 Hz, J H-F =48.8 Hz, CHF), 3.80 (s, 3H, COOCH 3 ), 2.00-1.77 (m, 2H, CH 2 CHF), 1.49-1.18 (m, 24H, 12×CH 2 ), 0.88 (t, 3H, J=6.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=170.5 (d, J C-C-F =24 Hz, COO), 89.0 (d, J C-C-F =183 Hz, CF), 52.2, 32.3 (d, J C-C-F =21 Hz, CH 2 CHF), 31.9, 29.6, 29.5, 29.4, 29.3, 29.0, 24.4, 24.3, 22.7, 14.1.
19 F NMR (186 MHz, CDCl 3 ) δ=−192.5 (quintet, CHF).
2-Fluorohexadecanal (27)
Procedure N then Q
C 16 H 31 FO
MW: 258.42.
White solid. Yield 86%.
m.p.: 68-71° C.
1 H NMR (200 MHz, CDCl 3 ) δ=9.76 (d, 1H, J=5.8 Hz, CHO), 4.74 (dt, 1H, J H-H =4.8 Hz, J H-F =49.0 Hz, CHF), 1.86-1.68 (m, 2H, CH 2 CHF), 1.47-1.10 (m, 24H, 12×CH 2 ), 0.88 (t, 3H, J=5.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=200.4 (d, J C-C-F =36 Hz, CO), 95.0 (d, J C-F =178 Hz, CF), 31.9, 30.3 (d, J C-C-F =20 Hz, CH 2 ), 29.6, 29.5, 29.3, 29.2, 24.2, 24.1, 22.7, 14.1.
19 F NMR (186 MHz, CDCl 3 ) δ=−200.0 (m, CHF).
2-Fluoro-1-(thiazole-2-yl)hexadeca-1-ol (28)
Procedure A
C 19 H 34 FNOS
MW: 343.54.
Yellowish solid. Yield 40%.
m.p.: 46-49° C.
1 H NMR (200 MHz, CDCl 3 ) δ=7.89 (d, 1/7H, J=3.2 Hz, ArH), 7.75 (d, 6/7H, J=3.4 Hz, ArH), 7.45 (d, 1/7H, J=3.2 Hz, ArH), 7.35 (d, 6/7H, J=3.2 Hz, ArH), 5.22-5.05 (dm, 1H, J=13.4 Hz, CHOH), 5.01-4.66 (dm, 1H, J=51.6 Hz, CHF), 4.15 (d, 2/3H, J=4.6 Hz, CHOH), 3.91 (d, 1/3H, J=5.6 Hz, CHOH), 1.94-1.08 (m, 26H, 13×CH 2 ), 0.88 (t, 3H, J=6.2 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=170.0, 142.1, 119.7, 95.4 (d, J C-F =173 Hz, CF), 73.2 (d, J C-C-F =22 Hz, 1/3COH), 73.0 (d, J C-C-F =24 Hz, 2/3COH) 31.9, 30.6 (d, J C-C-F =21 Hz, CH 2 ), 29.6, 29.5, 29.4, 29.3, 25.0, 24.9, 22.7, 14.1.
19 F NMR (186 MHz, CDCl 3 ) δ=−190.2 (m, CHF), −194.3 (m, CHF).
MS (ESI) m/z (%): 344 [M+H, 100] + .
2-Fluoro-1-(thiazole-2-yl)hexadeca-1-one (29)
Procedure B
C 19 H 32 FNOS
MW: 341.53.
White solid. Yield 60%.
m.p.: 55-56° C.
1 H NMR (200 MHz, CDCl 3 ) δ=8.05 (d, 1H, J=3.0 Hz, ArH), 7.76 (d, 1H, J=3.0 Hz, ArH), 6.07 (ddd, 1H, J H-F =49.8 Hz, J H-H =3.8 Hz, J H-H =8.2 Hz, CHF), 2.19-1.91 (m, 2H, CH 2 CHF), 1.66-1.08 (m, 24H, 12×CH 2 ), 0.87 (t, 3H, J=6.6 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=189.4 (d, J C-C-F =19 Hz, CO), 164.1, 145.3, 127.1, 92.9 (d, J C-F =182 Hz, CF), 32.8 (d, J C-C-F =21 Hz, CH 2 ), 32.1, 29.9, 29.8, 29.7, 29.6, 29.5, 29.3, 24.9, 22.9, 14.3.
19 F NMR (186 MHz, CDCl 3 ) δ=−196.6 (m, CHF).
MS (ESI) m/z (%): 342 [M+H, 100] + .
Compounds 30 to
The following target compounds of the invention are synthesised according to the protocols above:
2-(4-(Hexyloxy)phenyl)ethanol (31)
Procedure O
C 14 H 22 O 2
MW: 222.32.
Colorless oil. Yield 97%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.14 (d, 2H, J=8.6 Hz, CH, Ph), 6.85 (d, 2H, J=8.8 Hz, CH, Ph), 3.94 (t, 2H, J=6.4 Hz, CH 2 OPh), 3.82 (t, 2H, J=5.2 Hz, CH 2 OH), 2.81 (t, 2H, J=6.4 Hz, PhCH 2 ), 1.81-1.71 (m, 2H, CH 2 CH 2 OPh), 1.50-1.26 (m, 6H, 3×CH 2 ), 0.91 (t, 3H, J=6.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=157.8, 130.2, 129.8, 114.6, 68.0, 63.7, 38.2, 31.5, 29.2, 25.6, 22.5, 14.0.
2-(4-(Hexyloxy)phenyl)acetaldehyde (32)
Procedure G
C 14 H 20 O 2
MW: 220.31.
Yellow oil. Yield 97%.
1 H NMR (200 MHz, CDCl 3 ) δ=9.72 (t, 1H, J=2.4 Hz, CHO), 7.13 (d, 2H, J=8.4 Hz, CH, Ph), 6.90 (d, 2H, J=8.6 Hz, CH, Ph), 3.96 (t, 2H, J=6.4 Hz, CH 2 OPh), 3.63 (d, 2H, J=2.4 Hz, PhCH 2 ), 1.92-1.74 (m, 2H, CH 2 CH 2 OPh), 1.54-1.27 (m, 6H, 3×CH 2 ), 0.92 (t, 3H, J=6.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=199.4, 158.2, 130.3, 123.1, 114.7, 67.7, 49.4, 31.2, 28.9, 25.4, 22.3, 13.7.
(E)-Methyl 4-(4-(hexyloxy)phenyl)but-2-enoate (33)
Procedure R
C 17 H 24 O 3
MW: 276.37.
Yellowish oil. Yield 86%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.16-7.05 (m, 3H, CH 2 CHCH, CH, Ph), 6.84 (d, 2H, J=8.0 Hz, CH, Ph), 5.79 (d, 1H, J=15.6 Hz, CHCOOMe), 3.94 (t, 2H, J=6.4 Hz, CH 2 OPh), 3.72 (s, 3H, COOCH 3 ), 3.46 (d, 2H, J=6.4 Hz, PhCH 2 ), 1.83-1.64 (m, 2H, CH 2 CH 2 OPh), 1.45-1.23 (m, 6H, 3×CH 2 ), 0.91 (t, 3H, J=6.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=166.9, 157.9, 148.1, 129.6, 129.3, 121.5, 114.6, 68.0, 51.4, 37.6, 31.5, 29.2, 25.7, 22.5, 14.0.
MS (ESI) m/z (%): 277 [M+H, 100] + .
Methyl 4-(4-(hexyloxy)phenyl)butanoate (34)
Procedure S
C 17 H 26 O 3
MW: 278.39.
Colorless oil. Yield 91%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.08 (d, 2H, J=8.6 Hz, CH, Ph), 6.83 (d, 2H, J=8.6 Hz, CH, Ph), 3.93 (t, 2H, J=6.6 Hz, CH 2 OPh), 3.67 (s, 3H, COOCH 3 ), 2.60 (t, 2H, J=7.2 Hz, PhCH 2 ), 2.33 (t, 2H, J=7.2 Hz, CH 2 COOMe), 2.05-1.89 (m, 2H, CH 2 CH 2 COOMe), 1.86-1.71 (m, 2H, CH 2 CH 2 OPh), 1.54-1.23 (m, 6H, 3×CH 2 ), 0.92 (t, 3H, J=6.6 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=173.9, 157.4, 133.0, 129.2, 114.3, 67.9, 51.3, 34.1, 33.2, 31.5, 29.2, 26.6, 25.7, 22.5, 13.9.
4-(4-(Hexyloxy)phenyl)butanal (35)
Procedure N then G
C 16 H 24 O 2
MW: 248.36.
Yellow oil. Yield 99%.
1 H NMR (200 MHz, CDCl 3 ) δ=9.76 (t, 1H, J=1.6 Hz, CHO), 7.08 (d, 2H, J=8.6 Hz, CH, Ph), 6.83 (d, 2H, J=8.6 Hz, CH, Ph), 3.94 (t, 2H, J=6.6 Hz, CH 2 OPh), 2.61 (t, 2H, J=7.4 Hz, PhCH 2 ), 2.49-2.37 (m, 2H, CH 2 CHO), 2.06-1.90 (m, 2H, CH 2 CH 2 CHO), 1.86-1.71 (m, 2H, CH 2 CH 2 OPh) 1.49-1.27 (m, 6H, 3×CH 2 ), 0.91 (t, 3H, J=6.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=202.4, 157.4, 133.0, 129.2, 114.4, 68.0, 43.1, 34.1, 31.6, 29.3, 25.7, 23.8, 22.6, 14.0.
5-(4-(Hexyloxy)phenyl)-2-hydroxypentanenitrile (36)
Procedure T
C 17 H 25 NO 2
MW: 275.39.
Colorless oil. Yield 74%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.08 (d, 2H, J=8.8 Hz, CH, Ph), 6.83 (d, 2H, J=8.8 Hz, CH, Ph), 4.43 (t, 1H, J=6.2 Hz, CHOH), 3.94 (t, 2H, J=6.6 Hz, CH 2 OPh), 2.63 (t, 2H, J=6.4 Hz, PhCH 2 ), 2.28 (br s, 1H, OH), 1.93-1.61 (m, 6H, 3×CH 2 ), 1.53-1.23 (m, 6H, 3×CH 2 ), 0.91 (t, 3H, J=6.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=157.4, 132.9, 129.2, 119.9, 114.5, 68.0, 61.0, 34.5, 34.0, 31.5, 29.2, 26.3, 25.7, 22.5, 14.0.
MS (ESI) m/z (%): 293 [M+H 2 O, 100] + .
Methyl 5-(4-(hexyloxy)phenyl)-2-hydroxypentanoate (37)
Procedure U
C 18 H 28 O 4
MW: 308.41.
Colorless oil. Yield 86%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.08 (d, 2H, J=8.6 Hz, CH, Ph), 6.81 (d, 2H, J=8.6 Hz, CH, Ph), 4.20 (t, 1H, J=6.8 Hz, CHOH), 3.93 (t, 2H, J=6.6 Hz, CH 2 OPh), 3.78 (s, 3H, COOCH 3 ), 3.00 (br s, 1H, CHOH), 2.58 (t, 2H, J=6.6 Hz, PhCH 2 ), 1.86-1.55 (m, 6H, 3×CH 2 ), 1.52-1.17 (m, 6H, 3×CH 2 ), 0.91 (t, 3H, J=6.6 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=175.5, 157.2, 133.7, 129.1, 114.3, 70.3, 67.9, 52.4, 34.5, 33.8, 31.5, 29.2, 26.7, 25.7, 22.5, 14.0.
MS (ESI) m/z (%): 309 [M+H, 100] + .
Methyl 2-fluoro-5-(4-(hexyloxy)phenyl)pentanoate (38)
Procedure P
C 18 H 27 FO 3
MW: 310.40.
Colorless oil. Yield 37% (182 mg).
1 H NMR (200 MHz, CDCl 3 ) δ=7.08 (d, 2H, J=8.6 Hz, CH, Ph), 6.83 (d, 2H, J=8.8 Hz, CH, Ph), 4.93 (dt, 1H, J H-H =5.8 Hz, J H-F =50.2 Hz, CHF), 3.94 (t, 2H, J=6.6 Hz, CH 2 OPh), 3.79 (s, 3H, COOCH 3 ), 2.61 (t, 2H, J=7.4 Hz, PhCH 2 ), 2.05-1.62 (m, 6H, 3×CH 2 ), 1.56-1.23 (m, 6H, 3×CH 2 ), 0.91 (t, 3H, J=6.6 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=170.3 (d, J C-C-F =23 Hz, COO), 157.4, 133.2, 129.2, 114.4, 88.8 (d, J C-F =183 Hz, CF), 68.0, 52.3, 34.3, 32.0, 31.6, 29.3, 26.3, 25.7, 22.6, 14.0.
19 F NMR (186 MHz, CDCl 3 ) δ=−192.4 (m, CHF).
MS (ESI) m/z (%): 328 [M+H 2 O, 100] + , 311 [M+H, 15] + .
2-Fluoro-5-(4-(hexyloxy)phenyl)pentanal (39)
Procedure N then Q
C 17 H 25 FO 2
MW: 280.38.
Yellow oil. Yield 50%.
1 H NMR (200 MHz, CDCl 3 ) δ=9.74 (d, 1H, J=6.2 Hz, CHO), 7.08 (d, 2H, J=8.4 Hz, CH, Ph), 6.84 (d, 2H, J=8.4 Hz, CH, Ph), 4.76 (dm, 1H, J H-F =51.4 Hz, CHF), 3.94 (t, 2H, J=6.6 Hz, CH 2 OPh), 2.62 (t, 2H, J=7.2 Hz, PhCH 2 ), 1.93-1.72 (m, 6H, 3×CH 2 ), 1.54-1.24 (m, 6H, 3×CH 2 ), 0.93 (t, 3H, J=6.6 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=200.0 (d, J C-C-F =34 Hz, CHO), 157.4, 133.0, 129.2, 114.4, 94.8 (d, J C-F =178 Hz, CF), 67.9, 34.3, 31.5, 29.6 (d, J C-C-F =20 Hz, CH 2 CHF), 29.2, 26.1, 25.7, 22.6, 14.0.
19 F NMR (186 MHz, CDCl 3 ) δ=−199.8 (m, CHF).
2-Fluoro-5-(4-(hexyloxy)phenyl)-1-(thiazol-2-yl)pentan-1-ol (40)
Procedure A
C 20 H 28 FNO 2 S
MW: 365.51.
Yellow oil. Yield 38%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.90 (d, 1/7H, J=3.2 Hz, ArH), 7.83 (d, 6/7H, J=3.2 Hz, ArH), 7.45 (d, 1/7H, J=3.2 Hz, ArH), 7.35 (d, 6/7H, J=3.2 Hz, ArH), 7.05 (d, 2H, J=8.6 Hz, CH, Ph), 6.80 (d, 2H, J=8.6 Hz, CH, Ph), 5.15 (dd, 1H, J H-H =4.6 Hz, J H-F =12.8 Hz, CHOH), 4.99-4.65 (dm, 1H, J H-F =48.2 Hz, CHF), 3.93 (t, 2H, J=6.4 Hz, CH 2 OPh), 2.56 (t, 2H, J=7.2 Hz, PhCH 2 ), 1.88-1.27 (m, 12H, 6×CH 2 ), 0.91 (t, 3H, J=6.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=170.2, 157.2, 142.1, 133.7, 129.1, 119.7, 114.3, 95.1 (d, J C-F =174 Hz, CF), 73.0 (d, 1/3C, J C-C-F =21 Hz, COH), 72.9 (d, 2/3C, J C-C-F =24 Hz, COH), 67.9, 34.5, 31.5, 30.4 (d, J C-C-F =20 Hz, CH 2 ), 29.2, 26.9, 25.7, 22.5, 14.0.
19 F NMR (186 MHz, CDCl 3 ) δ=−190.0 (m, CHF), −194.4 (m, CHF).
MS (ESI) m/z (%): 366 [M+H, 100] + .
2-Fluoro-5-(4-(hexyloxy)phenyl)-1-(thiazol-2-yl)pentan-1-one (41)
Procedure B
C 20 H 26 FNO 2 S
MW: 363.49.
Colorless oil. Yield 60%.
1 H NMR (200 MHz, CDCl 3 ) δ=8.04 (d, 1H, J=2.8 Hz, ArH), 7.75 (d, 1H, J=3.0 Hz, ArH), 7.07 (d, 2H, J=8.4 Hz, CH, Ph), 6.80 (d, 2H, J=8.6 Hz, CH, Ph), 5.98 (ddd, 1H, J H-F =49.6 Hz, J H-H =7.6 Hz, J H-H =3.6 Hz, CHF), 3.92 (t, 2H, J=6.6 Hz, CH 2 OPh), 2.75-2.52 (m, 2H, PhCH 2 ), 2.30-1.70 (m, 6H, 3×CH 2 ), 1.59-1.26 (m, 6H, 3×CH 2 ), 0.91 (t, 3H, J=6.6 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=188.9 (d, J C-C-F =19 Hz, CO), 163.8, 157.4, 145.1, 133.3, 129.2, 126.9, 114.4, 92.3 (d, J C-F =182 Hz, CF), 68.0, 34.3, 32.0 (d, J C-C-F =21 Hz, CH 2 CHF), 31.6, 29.3, 26.6, 25.7, 22.6, 14.0.
19 F NMR (186 MHz, CDCl 3 ) δ=−196.2 (m, CHF).
MS (ESI) m/z (%): 364 [M+H, 100] + .
The following new target compounds are therefore synthesised
TABLE 1
2-Oxo-thiazoles.
Corres
Number
No.
Structure
MW
ClogP
GK146
3a
323.54
8.1
GK147
3b
245.34
3.7
GK149
3d
371.58
8.3
GK150
9
317.45
5.4
GK151
15a
395.60
8.3
GK152
15b
317.40
3.8
GK153
19
345.50
6.3
GK154
24
359.53
7.1
GK155
29
341.53
7.8
GK156
41
363.49
6.0
A series of further compounds have been synthesised based on the principles outlined above. These are listed in table 2
TABLE 2
GK148
GK157
GK158
GK159
GK160
GK162
GK179
GK180
GK181
GK182
GK183
GK184
GK198
GK199
GK201
GK202
GK203
GK204
Synthetic Schemes
Characterization Data
The following target compounds of the invention are synthesised according to the protocols above:
N-methoxy-N-methyloleamide (4c)
Prepared by Procedure C
C 20 H 39 NO 2
MW: 325.53
Colorless oil. Yield 86% (985 mg).
1 H NMR (200 MHz, CDCl 3 ) δ=5.34-5.29 (m, 2H, CH═CH), 3.65 (s, 3H, OMe), 3.15 (s, 3H, NMe), 2.38 (t, 2H, J=7.4 Hz, CH 2 CO), 1.99 (m, 4H, CH 2 CH═CHCH 2 ), 1.60 (m, 2H, CH 2 CH 2 CO), 1.29-1.24 (m, 20H, 10×CH 2 ), 0.85 (t, 3H, J=5.2 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=174.5, 129.8, 129.6, 61.0, 31.8, 29.6, 29.6, 29.4, 29.3, 29.2, 27.0, 25.5, 24.5, 22.5, 14.0.
N-methoxy-N-methyl-5-(naphthalen-2-yl)pentanamide (4e)
Prepared by Procedure C
C 17 H 21 NO 2
MW: 271.35
Colorless oil. Yield 75% (310 mg).
1 H NMR (CDCl 3 ): δ=7.90-7.30 (m, 7H, ArH), 3.65 (s, 3H, OMe), 3.18 (s, 3H, NMe), 2.82 (t, 2H, J=7.2 Hz, CH 2 ), 2.47 (t, 2H, J=7.0 Hz, CH 2 ), 1.98-1.60 (m, 4H, 2×CH 2 ).
MS (ESI) m/z (%): 272 [M+H, 100] + .
(Z)-1-morpholinooctadec-9-en-1-one (5c)
Prepared by Procedure D
C 22 H 41 NO 2
MW: 351.57
Colorless oil. Yield 98% (1.59 g).
1 H NMR (200 MHz, CDCl 3 ) δ=5.31-5.25 (m, 2H, CH═CH), 3.62-3.57 (m, 6H, CH 2 OCH 2 , CHHNCHH), 3.40 (t, 2H, J=5.0 Hz, CHHNCHH), 2.25 (t, 2H, J=7.4 Hz, CH 2 CO), 1.97-1.93 (m, 4H, CH 2 CH═CHCH 2 ), 1.60-1.53 (m, 2H, CH 2 CH 2 CO), 1.26-1.21 (m, 20H, 10×CH 2 ), 0.82 (t, 3H, J=6.2 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=171.6, 129.8, 129.5, 66.8, 66.5, 45.8, 41.7, 32.9, 31.7, 29.6, 29.5, 29.3, 29.2, 29.1, 28.9, 27.0, 25.0, 22.5, 13.9.
(Z)-1-(Thiazol-2-yl)octadec-9-en-1-one (3c)
Prepared by Procedure E
Yield when the Weinreb amide was used: 70%
Yield when the morpholine amide was used: 70%
5-(Naphthalen-2-yl)-1-(thiazol-2-yl)pentan-1-one (3e)
Prepared by Procedure E
C 18 H 17 NOS
MW: 295.40
Yellow solid. Yield 70%
1 H NMR (200 MHz, CDCl 3 ) δ=7.97 (d, 1H, J=3.0 Hz, ArH), 7.80-7.75 (m, 3H, ArH), 7.75-7.63 (m, 2H, ArH), 7.50-7.30 (m, 3H, ArH), 3.21 (t, 2H, J=7.0 Hz, CH 2 ), 2.83 (t, 2H, J=6.8 Hz, CH 2 ), 1.98-1.80 (m, 4H, 2×CH 2 ).
13 C NMR (50 MHz, CDCl 3 ) δ=193.8, 167.1, 144.6, 139.6, 133.5, 131.9, 127.8, 127.5, 127.4, 127.3, 126.3, 126.1, 125.8, 125.0, 38.2, 35.7, 30.8, 23.6.
MS (ESI) m/z (%): 296 [M+H, 100] + .
1-(Benzo[d]thiazol-2-yl)hexadecan-1-one (6a)
Prepared by Procedure E
C 23 H 35 NOS
MW: 373.60
Yellowish solid.
Yield via Weinreb amide 60% (140 mg).
Yield via morpholine amide 85% (180 mg).
m.p.: 74-76° C.
1 H NMR (200 MHz, CDCl 3 ) δ=8.19 (d, 1H, J=7.4 Hz, benzothiazole), 7.98 (d, 1H, J=7.4 Hz, benzothiazole), 7.62-7.49 (m, 2H, benzothiazole), 3.27 (t, 2H, J=7.2 Hz, CH 2 CO), 1.86-1.74 (m, 2H, CH 2 CH 2 CO), 1.44-1.21 (m, 24H, 12×CH 2 ), 0.88 (t, 3H, J=6.0 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=195.6, 166.6, 153.5, 137.2, 127.5, 126.8, 125.3, 122.4, 38.5, 31.9, 29.6, 29.6, 29.4, 29.3, 29.3, 29.1, 23.9, 22.6, 14.1.
MS (ESI) m/z (%): 374 [M+H, 100] + .
1-(Benzo[d]thiazol-2-yl)-5-phenylpentan-1-one (6b)
Prepared by Procedure E
C 18 H 17 NOS
MW: 295.40
Yellow solid.
Yield via Weinreb amide 77% (204 mg).
Yield via morpholine amide 72% (126 mg).
m.p.: 66-68° C.
1 H NMR (200 MHz, CDCl 3 ) δ=8.19 (d, 1H, J=7.4 Hz, benzothiazole), 7.96 (d, 1H, J=7.6 Hz, benzothiazole), 7.61-7.47 (m, 2H, benzothiazole), 7.34-7.15 (m, 5H, Ph), 3.31 (t, 2H, J=6.8 Hz, CH 2 CO), 2.70 (t, 2H, J=7.4 Hz, PhCH 2 ), 1.96-1.69 (m, 4H, 2×CH 2 ).
13 C NMR (50 MHz, CDCl 3 ) δ=195.2, 166.3, 153.4, 142.0, 137.1, 128.3, 128.2, 127.5, 126.8, 125.6, 125.2, 122.3, 38.2, 35.5, 30.8, 23.4.
MS (ESI) m/z (%): 296 [M+H, 100] + .
(Z)-1-(Benzo[d]thiazol-2-yl)octadec-9-en-1-one (6c)
Prepared by Procedure E
C 25 H 37 NOS
MW: 399.63
Yellow oil.
Yield via Weinreb amide 70% (170 mg).
1 H NMR (200 MHz, CDCl 3 ) δ=8.17 (d, 1H, J=7.0 Hz, benzothiazole), 7.95 (d, 1H, J=6.2 Hz, benzothiazole), 7.60-7.45 (m, 2H, benzothiazole), 5.42-5.27 (m, 2H, CH═CH), 3.26 (t, 2H, J=7.4 Hz, CH 2 CO), 2.02-2.00 (m, 4H, CH 2 CH═CHCH 2 ), 1.88-1.73 (m, 2H, CH 2 CH 2 CO), 1.43-1.25 (m, 20H, 10×CH 2 ), 0.87 (t, 3H, J=6.4 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ=195.4, 166.5, 153.4, 137.1, 129.9, 129.6, 127.4, 126.8, 125.2, 122.3, 38.5, 31.8, 29.7, 29.6, 29.4, 29.2, 29.2, 29.1, 29.0, 27.1, 27.1, 23.8, 22.6, 14.0.
MS (ESI) m/z (%): 400 [M+H, 100] + .
1-(Benzo[d]thiazol-2-yl)-5-(naphthalen-2-yl)pentan-1-one (6e)
Prepared by Procedure E
C 22 H 19 NOS
MW: 345.46
Yellow solid. Yield 72%.
1 H NMR (200 MHz, CDCl 3 ) δ=8.20 (d, 1H, J=6.0 Hz, ArH), 7.97 (d, 1H, J=8.0 Hz, ArH), 7.90-7.70 (m, 3H, ArH), 7.70-7.30 (m, 6H, ArH), 3.35 (t, 2H, J=7.0 Hz, CH 2 ), 2.90 (t, 2H, J=6.8 Hz, CH 2 ), 2.05-1.82 (m, 4H, 2×CH 2 ).
13 C NMR (50 MHz, CDCl 3 ) δ=195.3, 166.4, 153.5, 139.6, 137.2, 133.5, 131.9, 127.8, 127.6, 127.5, 127.4, 127.3, 126.9, 126.4, 125.8, 125.3, 125.0, 122.4, 38.3, 35.8, 30.7, 23.6.
MS (ESI) m/z (%): 246 [M+H, 100] + .
Ethyl 2-(2-(1-hydroxyhexadecyl)thiazol-4-yl)acetate (14c)
Prepared by Procedure K
C 23 H 41 NO 3 S
MW: 411.64
White solid.
1 H NMR (300 MHz, CDCl 3 ): δ=7.15 (s, 1H, SCH), 4.97 (dd, J 1 =7.8 Hz, J 2 =4.5 Hz, 1H, CHOH), 4.20 (q, J=7.2 Hz, 2H, COOCH 2 ), 3.82 (s, 2H, CH 2 COO), 2.07-1.78 (m, 2H CH 2 ), 1.59-1.20 (m, 29H, 13×CH 2 , CH 3 ), 0.89 (t, J=6.3 Hz, 3H, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ): δ=174.98, 170.36, 148.18, 115.97, 71.95, 61.08, 38.32, 36.93, 31.91, 29.68, 29.66, 29.56, 29.49, 29.36, 25.20, 22.69, 14.14.
MS (ESI) m/z (%): 412 [M+H, 100] + .
Ethyl 2-(2-(1-hydroxy-5-phenylpentyl)thiazol-4-yl)acetate (14d)
Prepared by Procedure K
C 18 H 23 NO 3 S
MW: 333.45
Pale yellow solid; Yield 44%.
m.p. 53-55° C.
1 H NMR (200 MHz, CDCl 3 ): δ 7.35-7.07 (m, 6H, SCH, Ph), 4.93 (dd, J 1 =7.8 Hz, J 2 =4.8 Hz, 1H, CHOH), 4.18 (q, J=7.0 Hz, COOCH 2 ), 3.79 (s, 2H, CH 2 COO), 2.61 (t, J=7.2 Hz, CH 2 Ph), 2.06-1.37 (m, 6H, 3×CH 2 ), 1.26 (t, J=7.2 Hz, 3H, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ) δ 174.95, 170.37, 148.20, 142.38, 128.34, 128.24, 125.65, 116.00, 71.80, 61.08, 38.12, 36.90, 35.74, 31.19, 24.89, 14.15.
MS (ESI) m/z (%): 334 [M+H, 100] + .
Ethyl 2-(2-palmitoylthiazol-4-yl)acetate (15c)
Prepared by Procedure B
C 23 H 39 NO 3 S
MW: 409.63
White solid. Yield 90%.
m.p. 46-48° C.
1 H NMR (300 MHz, CDCl 3 ): δ=7.54 (s, 1H, SCH), 4.21 (q, J=7.2 Hz, 2H, COOCH 2 )), 3.90 (s, 2H, CH 2 COO), 3.12 (t, J=7.5 Hz, 2H, CH 2 CO), 1.82-1.62 (m, 2H CH 2 ), 1.55-1.19 (m, 27H, 12×CH 2 , CH 3 ), 0.88 (t, J=7.0 Hz, 3H, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ): δ=194.09, 170.00, 166.52, 150.95, 123.56, 61.24, 38.43, 37.00, 31.91, 29.65, 29.47, 29.39, 29.35, 29.18, 23.91, 22.68, 14.13.
MS (ESI) m/z (%): 410 [M+H, 100] + .
Ethyl 2-(2-(5-phenylpentanoyl)thiazol-4-yl)acetate (15d)
Prepared by Procedure B
C 18 H 21 NO 3 S
MW: 331.43
White oil. Yield 81%.
1 H NMR (300 MHz, CDCl 3 ): δ=7.55 (s, 1H, SCH), 7.34-7.16 (m, 5H, Ph), 4.22 (q, J=7.2 Hz, 2H, COOCH 2 ), 3.91 (s, 2H, CH 2 COO), 3.17 (t, J=7.5 Hz, 2H, CH 2 CO), 2.68 (t, J=7.2 Hz, 2H, CH 2 Ph), 1.85-1.63 (m, 4H, 2×CH 2 ), 1.30 (t, J=7.2 Hz, 3H, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ): δ=193.82, 169.99, 166.42, 150.99, 142.17, 128.39, 128.27, 125.71, 123.69, 61.26, 38.17, 36.99, 35.65, 30.92, 23.56, 14.16.
MS (ESI) m/z (%): 332 [M+H, 99] + .
Ethyl 2-(2-(5-(biphenyl-4-yl)pentanoyl)thiazol-4-yl)acetate (15e)
Prepared by Procedure B
C 24 H 25 NO 3 S
MW: 407.53
White solid.
1 H NMR (200 MHz, CDCl 3 ): δ=7.65-7.18 (m, 10H, Ar, SCH), 4.21 (q, J=7.4 Hz, 2H, COOCH 2 ), 3.90 (s, 2H, CH 2 COO), 3.18 (t, J=6.6 Hz, CH 2 CO), 2.70 (t, J=7.2 Hz, CH 2 Ph), 1.94-1.65 (m, 4H, 2×CH 2 ), 1.28 (t, J=7.2 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 ): δ=193.79, 169.95, 166.40, 151.01, 141.29, 141.06, 138.66, 128.80, 128.66, 127.01, 126.95, 123.67, 61.22, 38.15, 36.97, 35.25, 30.85, 23.57, 14.14.
MS (ESI) m/z (%): 408 [M+H, 100] + .
2-palmitoylthiazole-4-carboxylic acid (15′ a)
Prepared by Procedures L, then B
C 20 H 33 NO 3 S
MW: 367.55
White solid. Yield 50%.
m.p. 98-100° C.
1 H NMR (200 MHz, CDCl 3 ): δ=8.39 (s, 1H, CH), 3.25-3.00 (m, 2H, CH 2 ), 1.80-1.55 (m, 2H, CH 2 ), 1.40-1.00 (m, 24H, 12×CH 2 ), 0.88 (t, 3H, J=6.8 Hz, CH 3 ).
13 C NMR (50 MHz, CDCl 3 +CD 3 OD): δ=193.9, 166.4, 164.6, 151.5, 131.8, 37.9, 31.5, 29.2, 29.0, 28.9, 28.7, 23.2, 22.2, 13.4.
MS (ESI) m/z (%): 366 [M−H, 100]-.
2-(5-Phenylpentanoyl)thiazole-4-carboxylic acid (15′b)
Prepared by Procedure M
C 15 H 15 NO 3 S
MW: 289.35
White solid. Yield 86% (25 mg).
1 H NMR (CDCl 3 ): δ=8.55 (s, 2H, ArH, COOH), 7.30-7.10 (m, 5H, Ph), 3.26 (t, 2H, J=6.8 Hz, CH 2 ), 2.66 (t, 2H, J=7.0 Hz, CH 2 ), 1.90-1.63 (m, 4H, 2×CH 2 ).
13 C NMR (CDCl 3 ): δ=193.5, 167.8, 164.6, 147.4, 142.0, 134.9, 128.4, 128.3, 125.8, 38.2, 35.6, 30.7, 23.2.
MS (ESI) m/z (%): 290 [M+H, 47] + .
2-(2-Palmitoylthiazol-4-yl)acetic acid (15′c)
Prepared by Procedures L, then B
C 21 H 35 NO 3 S
MW: 381.57
White solid.
1 H NMR (300 MHz, CDCl 3 ): δ 7.55 (s, 1H, SCH), 3.98 (s, 2H, CH 2 COO), 3.13 (t, J=7.6 Hz, 2H, CH 2 CO), 1.82-1.69 (m, 2H, CH 2 ), 1.43-1.18 (m, 24H, 12×CH 2 ), 0.89 (t, J=6.9 Hz, 3H, CH 3 ).
MS (ESI) m/z (%): 336 [M-COOH—H, 100] − , 380 [M−H, 46] − .
2-(2-(5-Phenylpentanoyl)thiazol-4-yl)acetic acid (15′ d)
Prepared by Procedure M
C 16 H 17 NO 3 S
MW: 303.38
White oil. Yield 89%.
1 H NMR (300 MHz, CDCl 3 ): δ 7.49 (s, 1H, SCH), 7.35-7.08 (m, 5H, Ph), 3.88 (s, 2H, CH 2 COO), 3.11 (t, J=7.5 Hz, 2H, CH 2 CO), 2.63 (t, J=7.0 Hz, 2H, CH 2 Ph), 1.85-1.63 (m, 4H, 2×CH 2 ).
MS (ESI) m/z (%): 304 [M+H, 77] + .
(S)-tert-Butyl 4-(benzyloxycarbonylamino)-5-(methoxy(methyl)amino)-5-oxopentanoate (43b)
Prepared by Procedure C
C 19 H 28 N 2 O 6
MW: 380.44
Colorless oil. Yield 100%.
1 H NMR (200 MHz, CDCl 3 ) δ=7.35-7.20 (m, 5H, ArH), 5.67 (d, 1H, J=8.0 Hz, NH), 5.06 (s, 2H, CH 2 ), 4.80-4.60 (m, 1H, CH), 3.73 (s, 3H, OMe), 3.15 (s, 3H, NMe), 2.40-1.70 (m, 4H, CH 2 ), 1.38 (s, 9H, t Bu).
13 C NMR (50 MHz, CDCl 3 ) δ=171.9, 155.9, 136.1, 128.3, 127.9, 127.8, 80.3, 66.6, 61.4, 50.3, 31.9, 31.0, 27.9, 27.4.
MS (ESI) m/z (%): 381 [M+H, 100] + .
(S)-tert-Butyl 5-(methoxy(methyl)amino)-5-oxo-4-(2-phenylacetamido)pentanoate (45b)
Prepared by Procedures V, then W
C 19 H 28 N 2 O 5
MW: 364.44
Colorless oil.
1 H NMR (200 MHz, CDCl 3 ) δ=7.40-7.20 (m, 5H, ArH), 6.38 (d, 1H, J=8.0 Hz, NH), 5.02-4.90 (m, 1H, CH), 3.65 (s, 3H, OMe), 3.55 (s, 2H, CH 2 ), 3.18 (s, 3H, NMe), 2.25-1.70 (m, 4H, CH 2 ), 1.40 (s, 9H, t Bu).
13 C NMR (50 MHz, CDCl 3 ) δ=172.1, 170.9, 166.3, 134.6, 129.3, 128.9, 127.2, 80.5, 61.6, 48.7, 43.6, 31.1, 28.0, 27.2.
MS (ESI) m/z (%): 365 [M+H, 100] + .
N-(2-(Benzo[d]thiazol-2-yl)-2-oxoethyl)-2-phenylacetamide (46a)
Prepared by Procedure E
C 17 H 14 N 2 O 2 S
MW: 310.37
Orange solid.
1 H NMR (200 MHz, CDCl 3 ) δ=8.11 (d, 1H, J=8.0 Hz, ArH), 7.94 (d, 1H, J=8.0 Hz, ArH), 7.65-7.40 (m, 2H, ArH), 7.39-7.20 (m, 5H, ArH), 6.34 (b, 1H, NH), 4.95 (d, 2H, J=5.2 Hz, CH 2 ), 3.67 (s, 2H, CH 2 ).
13 C NMR (50 MHz, CDCl 3 ) δ=189.7, 171.4, 163.1, 153.3, 136.9, 134.4, 129.5, 129.0, 128.1, 127.4, 127.1, 125.6, 122.3, 46.8, 43.5.
MS (ESI) m/z (%): 311 [M+H, 100] + .
(S)-tert-Butyl 5-(benzo[d]thiazol-2-yl)-5-oxo-4-(2-phenylacetamido)pentanoate (46b)
Prepared by Procedure E
C 24 H 26 N 2 O 4 S
MW: 438.54
Colorless Oil. Yield 50%.
1 H NMR (200 MHz, CDCl 3 ) δ=8.10 (d, 1H, J=8.0 Hz, ArH), 7.91 (d, 1H, J=8.0 Hz, ArH), 7.62-7.20 (m, 7H, ArH), 6.77 (d, 1H, J=8.0 Hz, NH), 5.68-5.70 (m, 1H, CH), 3.61 (s, 2H, CH 2 ), 2.50-1.98 (m, 4H, CH 2 ), 1.38 (s, 9H, t Bu).
13 C NMR (50 MHz, CDCl 3 ) δ=192.5, 172.1, 170.9, 163.5, 153.2, 137.0, 134.4, 129.3, 128.8, 127.9, 127.2, 127.0, 125.8, 122.2, 80.7, 55.1, 43.4, 30.3, 30.6, 27.9, 27.3.
MS (ESI) m/z (%): 439 [M+H, 55] + .
(S)-5-(Benzo[d]thiazol-2-yl)-5-oxo-4-(2-phenylacetamido)pentanoic acid (47)
Prepared by Procedure X
C 20 H 18 N 2 O 4 S
MW: 382.43
Yellow solid. Yield 50%.
1 H NMR (200 MHz, CDCl 3 ) δ=8.11 (d, 1H, J=8.0 Hz, ArH), 7.94 (d, 1H, J=8.0 Hz, ArH), 7.65-7.40 (m, 2H, ArH), 7.38-7.10 (m, 5H, ArH), 6.71 (d, 1H, T=8.0 Hz, NH), 5.90-5.60 (m, 1H, CH), 3.63 (s, 2H, CH 2 ), 2.55-2.25 (m, 3H, CH 2 ), 2.20-1.90 (m, 1H, CH 2 ).
13 C NMR (50 MHz, CDCl 3 ) δ=192.3, 177.0, 171.6, 163.3, 153.3, 137.1, 134.2, 129.4, 129.0, 128.2, 127.5, 127.2, 126.1, 125.8, 122.3, 55.2, 43.5, 30.1, 27.5.
MS (ESI) m/z (%): 381 [M−H, 100] − .
Some of the compounds above were tested using an in vitro cPLA 2 enzyme activity assay.
In Vitro cPLA2 Assay
Assay for cPLA2 activity was performed by the use of sonicated vesicles of 1-palmitoyl-2-arachidonoyl-sn-glycerol-3-phosphorylcholine (100 μM) containing 100,000 cpm of 1-palmitoyl-2-[1 14C]arachidonoylsn-glycerol-3-phosphorylcholine in 100 mM Hepes, pH 7.5, 80 μM Ca2, 2 mM dithiothreitol, and 0.1 mg/ml BSA as described. Following a 35-mM incubation at 37° C., the reaction was terminated (derived from Wijkander et al). The lower phase was separated by thin layer chromatography, and the spot corresponding to free [1-14C]arachidonic acid was visualized by digital imaging and quantified with a PhosphorImager (Fuji Instruments). The source of cPLA 2 enzyme was recombinant overexpression of the human gene for group IVa PLA2 in baculovirus insect cell expression system, as described in Abdullah et al.
Wijkander, J., and Sundler, R. (1991) Eur. J. Biochem. 202, 873-880 Abdullah, K., et al. (1995) Human cytosolic phospholipase A2 expressed in insect cells is extensively phosphorylated on Ser-505. Biochim Biophys Acta. 1995 May 11; 1244(1):157-64.
The results are presented below:
Compound No. Enzyme Assay IC 50 3b 3050 nM 24 3650 nM 41 3700 nM
Further Testing was Carried Out as Follows
Reagents
The Cell Culture SW982 model cell line at a confluent or spheroid state (Wada Y, 2005) was used since gene expression and generation of proinflammatory cytokines resemble RA-derived synovial fibroblast-like cells.
AA release assay: 1 h preincubation at 50 and 25 μM-4 h IL-1B stimulation, repeated 2-3 times. Only inhibitors that showed a ˜50% inhibition in either of the initial two concentrations were further tested in a dose-response. IC50 is evaluated from dose-response inhibitions curves.
PGE2 Analysis
PGE 2 Detection
Samples and controls were slowly thawed and diluted (between 1:1 and 1:2500) in the standard diluent. The maximal dilution was 1:10 for one step. That is why several intermediate dilutions were prepared. In the beginning all values were determined from duplicates. After having minimized technical errors, samples were only analyzed as individuals. All further steps, except for some minor corrections, were performed according to the manufacturer's recommendations as can be found in the manual of the EIA kit. In order to optimize the results, the incubation time of the alkaline phosphatase substrate was prolonged by 15 minutes. During the incubation, the plates were kept in the dark. An example of the arrangements of the samples and controls is illustrated in the appendix. The read-out was carried out with a Multiscan plate reader (Ascent Labsystems) at wavelengths of 414 and 595 nm after 10 seconds shaking at 120 rpm. The corresponding software to obtain the data was the Ascent software for Multiscan, Version 2.4.1.
Data were processed using Microsoft Office Excel 2003 and SigmaPlot 10.0.
AA
release
cPLA2
SW982
in vitro
cells
assay
IC50
IC50
PGE2-assay
Code
Structure
(μM)
(μM)
% inhibition
GK150
5.8
Not yet known
GK152
7.4 (2 h) >25 (4 h)
>5
0.1 uM: 41% 3 uM:: 38% 10 uM:: 30% 30 uM: 31%
GK159
<2 (2 h) ~25 (4 h)
>5
0.3 uM:: 76% 3 uM: 18% 10 uM: 23% 30 uM: 10%
GK160
4.9
7.2
10 uM: 12% 30 uM: 30%
GK181
1.4
10 uM: 16.3% 30 uM: 22.5%
GK185
2.8
2
Not yet known
Other Embodiments
From the foregoing description, it will be apparent that variations and modifications may be made to the invention described herein to adopt it to various usages and conditions. Such embodiments are also within the scope of the following claims.
The recitation of a listing of elements in any definition of a variable herein includes definitions of that variable as any single element or combination (or subcombination) of listed elements. The recitation of an embodiment herein includes that embodiment as any single embodiment or in combination with any other embodiments or portions thereof.
All patents and publications mentioned in this specification are herein incorporated by reference to the same extent as if each independent patent and publication was specifically and individually indicated to be incorporated by reference.
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The invention provides compounds of formula (I)
wherein X is O or S;
R 1 is H, OH, SH, nitro, NH 2 , NHC 1-6 alkyl, N(C 1-6 alkyl) 2 , halo, haloC 1-6 alkyl, CN, C 1-6 -alkyl, OC 1-6 alkyl, C 1-6 alkylCOOH, C 1-6 alkylCOOC 1-6 alkyl, C 2-6 -alkenyl, C 3-10 cycloalkyl, C 6-10 aryl, C 1-6 alkylC 6-10 aryl, heterocyclyl, heteroaryl, CONH 2 , CONHC 1-6 alkyl, CON(C 1-6 alkyl) 2 , OCOC 1-6 alkyl, or is an acidic group, such as a group comprising a carboxyl, phosphate, phosphinate, sulfate, sulfonate, or tetrazolyl group;
R 2 is as defined for R 1 or R 1 and R 2 taken together can form a 6-membered aromatic ring optionally substituted by up to 4 groups R 5 ;
R 3 is H, halo (preferably fluoro), or CHal 3 (preferably CF 3 );
each R 5 is defined as for R 1 ;
V 1 is a covalent bond, —O—, or a C 1-20 alkyl group, or C 2-20 -mono or multiply unsaturated alkenyl group; said alkyl or alkenyl groups being optionally interrupted by one or more heteroatoms selected from O, NH, N(C 1-6 alkyl), S, SO, or SO 2 ;
M 1 is absent or is a C 5-10 cyclic group or a C 5-15 aromatic group; and
R 4 is H, halo, OH, CN, nitro, NH 2 , NHC 1-6 alkyl, N(C 1-6 alkyl) 2 , haloC 1-6 alkyl, a C 1-20 alkyl group, or C 2-20 -mono or multiply unsaturated alkenyl group, said C 1-20 alkyl or C 2-20 alkenyl groups being optionally interrupted by one or more heteroatoms selected from O, NH, N(C 1-6 alkyl), S, SO, or SO 2 ;
with the proviso that the group V 1 M 1 R 4 as a whole provides at least 4 backbone atoms from the C(R 3 ) group;
or a salt, ester, solvate, N-oxide, or prodrug thereof; for use in the treatment of a chronic inflammatory condition.
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BACKGROUND
[0001] The present invention relates to fluid compressors. More specifically, the invention relates to control algorithms for air compressors.
[0002] For positive displacement compressors, capacity (volumetric flow rate) is roughly proportional to an input speed provided by a prime mover. Power output required to maintain volumetric flow rate is dependent upon mass flow rate (volumetric flow rate multiplied by the air density). When ambient pressure decreases, such as when altitude increases, the density of the air decreases and the mass flow rate decreases. Since the amount of energy required by the air compressor is dependent upon mass flow rate, the amount of power used by the compressor element at a uniform speed decreases with decreased air density.
SUMMARY
[0003] In one embodiment, the invention provides a fluid compression system that includes a gaseous fluid compressor having a fluid inlet and a compressed fluid discharge, a prime mover coupled to the gaseous fluid compressor in driving relation, and a demand sensor positioned to measure a compressor demand and output a demand signal. An engine control unit is coupled to the prime mover and is operable to measure prime mover speed and prime mover power output. The engine control unit sets a variable maximum rated speed that maintains the engine power below a predetermined limit. A compressor controller unit is arranged to receive the demand signal and vary an operating speed based in part upon the demand signal. The operating speed is limited to the maximum rated speed set by the engine control unit.
[0004] In another embodiment the invention provides an air compression system that includes an air compressor including an ambient air inlet and a compressed air discharge, an engine coupled to the air compressor and operable to drive the air compressor to produce a flow of compressed air, and a receiver tank coupled to the compressed air discharge to receive the flow of compressed air and to maintain a volume of pressurized air. A demand sensor is positioned to measure a pressure of the receiver tank and is operable to generate a first signal related to the pressure of the receiver tank. An engine control unit is coupled to the engine to operate the engine at a desired operating speed in response to a control signal and is operable to measure engine speed and engine power to calculate a maximum engine speed at which the engine power is at a preset maximum value. A compressor control unit operable to generate the control signal to vary the desired operating speed in response to the first signal, the desired operating speed being limited to the maximum engine speed calculated by the engine control unit.
[0005] In yet another embodiment, the invention provides a method of controlling a gas compressor system. The method includes setting a maximum engine speed at a factory preset maximum engine speed. The factory preset maximum engine speed corresponds to a maximum desired engine power output at a first atmospheric pressure. The method also includes coupling the engine to a compressor such that the engine operates at an operating speed to drive the compressor at a speed that is proportional to the operating speed, delivering a flow of compressed gas in response to operation of the compressor; and sensing an actual power output of the engine at the operating speed. The method further includes changing the maximum engine speed to a new maximum engine speed based on the sensed actual engine power output at the operating speed to maintain the engine output at or below the maximum desired engine output, sensing a compressed gas demand, varying the operating speed of the engine in response to the sensed compressed gas demand, and limiting the operating speed to the new maximum engine speed.
[0006] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0007] FIG. 1 is a block diagram of an air compressor and compressor control system according to one aspect of the invention.
[0008] FIG. 2 is a graph of compressor speed versus power at several ambient pressure levels.
DETAILED DESCRIPTION
[0009] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawing. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
[0010] FIG. 1 illustrates an air compressor system 10 that includes a prime mover 14 , a compressor unit 18 , a receiver tank 22 , and a compressor control system 26 . The compressor unit 18 has an inlet 28 and a discharge 30 . An external load 32 , such as an air-operated tool, receives compressed air from the receiver tank 22 .
[0011] The prime mover 14 provides motive force (e.g., torque) for driving the compressor unit 18 . The illustrated prime mover 14 may be a diesel internal combustion engine. The prime mover 14 may also be a gasoline internal combustion engine, a gas turbine, an electric motor, or other suitable prime mover.
[0012] The compressor unit 18 receives torque from an output shaft 34 of the prime mover 14 . In some embodiments, the prime mover 14 and compressor unit 18 may be on a common shaft. In other embodiments, there may be a reduction arrangement between the prime mover and compressor to increase or decrease their relative speeds, as required.
[0013] In the illustrated example, the compressor unit 18 is a positive displacement type, as opposed to a dynamic-type. Positive displacement air compressors work by filling an air chamber with air and then reducing the chamber's volume. Examples of positive displacement compressors include reciprocating piston, rotary screw, rotary vane, and scroll compressors. The illustrated compressor unit 18 is a rotary screw compressor.
[0014] The compressor unit 18 is designed to deliver a volumetric flow rate (e.g., 1000 cubic feet per minute) of compressed gas (e.g., air) at an elevated pressure (e.g., 350 pounds per square inch). The compressed gas is discharged to the receiver tank 22 , where the compressed gas remains available for use by the external load 32 . In some constructions, filters, oil-separators, moisture separators and the like are disposed between the compressor unit and the external load.
[0015] The compressor control system 26 includes an engine control unit (ECU) 38 and a compressor control unit (CCU) 42 , and may include an ambient pressure sensor 46 , a receiver tank pressure sensor 50 , and an engine speed sensor 52 . Although these components of the compressor control system 26 are illustrated as being separate, it should be appreciated that two or more of the components may be combined. For example, in some embodiments the CCU 42 and ECU 38 may be integrated into a single combined controller. In some embodiments, the ambient pressure sensor may be integrated into an ECU or CCU housing or board. In still other embodiments, the ECU may monitor engine speed without a separate speed sensor, such as by monitoring the ignition signals.
[0016] The receiver tank pressure sensor 50 detects pressure within the receiver tank 22 and generates a first signal related to the receiver tank pressure. The first signal is received by the CCU 42 and provides an indication of when compressor speed (and therefore engine speed) should be increased to meet demand. In other embodiments, this function could be served with a load pressure sensor at the external load 32 , a discharge pressure sensor at the compressor discharge 30 , or using other control schemes that assure demand is met. It should be noted that in systems that do not employ a tank, the tank pressure sensor 50 may be replaced by another sensor that senses and indicates demand and allows the CCU 42 to adjust the compressor output to meet that demand.
[0017] The CCU 42 monitors compressor-related parameters, including receiver tank pressure as indicated by the receiver tank pressure sensor 50 . The ECU 38 monitors engine related parameters such as engine speed, engine torque, and engine power and receives commands from the CCU 42 to run at certain speeds under certain conditions. ECU 38 and CCU 42 communicate via a controller area network (CAN) communication protocol, or other protocol as may be appropriate.
[0018] The ECU 38 controls and adjusts performance of the engine (air/fuel mixture, power output, speed, etc.) to meet the demands placed on it. However, the ECU 38 is programmed or configured with limits based upon, for example, engine mechanical limitations. Maximum rated speed and maximum rated power output are examples of such limits. The ECU 38 may be configured to prevent the prime mover 14 from exceeding 95% of a maximum rated power output, for example. In some embodiments, the prime mover may incorporate a mechanical governor to prevent the prime mover from exceeding these limits.
[0019] In one mode of operation, the compressor unit 18 may deliver a desired volumetric capacity (e.g., 1000 cubic feet per minute (CFM)) of compressed air at a pressure (e.g., 350 pounds per square inch (PSI)) at a first operating speed (e.g., 1800 RPM) and at a standard atmospheric pressure. The prime mover 14 (e.g. a diesel engine) has a maximum rated power level which is greater than the power level required at the first operating speed of the compressor. In this first operating mode, the speed of the prime mover 14 (and thereby compressor speed) is controlled by commands from the CCU 42 .
[0020] As air demand from the external load 32 (e.g., a pneumatic driven power tool) increases, receiver tank pressure (as indicated by the receiver tank pressure sensor 50 ) decreases and the CCU 42 instructs the ECU 38 to increase engine speed, up to the maximum operating power limit of the prime mover (e.g., 95% of rated maximum power). When the maximum power level is reached, no additional flow can be delivered. However, if the ambient pressure is below the ambient pressure used to rate the prime mover (e.g., the altitude is higher), the power output of the prime mover 14 is actually lower than the rated power at that speed. In other words, the engine is actually not operating at its rated power output capacity due to the lower density of the air.
[0021] In prior compressor systems, the effects of changing altitude were not considered. Thus, the ECU prevented operation of the compressor above a speed that, at standard atmospheric pressure required the rated power of the prime mover 14 , even when the CCU indicated that the demand was not being met. In the preceding example, the ECU was programmed to inhibit engine operation beyond 95% power. The ECU achieved this by limiting the speed of the prime mover. However, at the higher altitude, the prime mover might actually be operating at only 85%. Thus, as altitude increases, the prime mover 14 operates at a decreasing percentage of its maximum power output limit and capacity of the compressor system 10 is unused.
[0022] The present invention provides the ability to compensate for altitude changes to the air compressor system 10 . Rather than limiting the speed of the prime mover based on a maximum speed rating that corresponds to a maximum power level at standard atmospheric conditions, the system measures the actual prime mover power level and adjusts the maximum rated prime mover speed to maintain the maximum power level at some predetermined value such as 95% of rated output. For example, the CCU 42 may be configured to increase the maximum operating speed until the power output (as determined by the ECU) is again 95% of the engine's maximum rated power output. Recalling that power is roughly proportional to speed for constant discharge pressures, the increase in power output from 85% to 95% results in an approximately 12% increase in airflow. Similarly, prime mover speed would increase within acceptable limits (e.g., from 1800 RPM to approximately 2016 RPM, with a maximum rated speed of 2100 RPM or greater).
[0023] An additional controller or the existing ECU 38 may read the power setting of the engine and command the ECU 38 to vary the speed to load the engine to a preset horsepower level. In another embodiment, the CCU 42 could be programmed so that absolute horsepower limits can be selected instead of a percentage of available power. An absolute upper engine speed could be programmed to prevent damage to the engine if the engine speed were to be too high (e.g., greater than 2100 RPM). A mode setting may be used to the select an ambient pressure compensated or uncompensated mode.
[0024] FIG. 2 illustrates graphically an example of the pressure compensated operating mode. FIG. 2 is a graph of compressor speed versus power, for three different ambient pressures P 1 , P 2 and P 3 , where P 1 >P 2 >P 3 . As ambient pressure decreases from P 1 to P 2 to P 3 , the maximum operating speed increases, without the compressor exceeding 95% of the maximum power output and without exceeding the maximum rated speed of the prime mover 14 or the compressor 18 .
[0025] The foregoing example provides for ambient pressure or altitude compensation without the need to measure the actual ambient pressure. In other constructions, an ambient pressure sensor is provided and the data from that sensor is used to compensate the prime mover operation.
[0026] The ambient pressure sensor 46 may be described as an altitude sensor, as ambient pressure generally decreases as altitude increases. However, it should be appreciated that ambient pressure at a given location and altitude also varies depending upon current atmospheric conditions, such as low or high pressure weather systems. The ambient pressure sensor 46 detects an ambient pressure and generates an ambient pressure signal related to the ambient pressure. In the illustrated embodiment, the ambient pressure signal is received by the CCU 42 . In other embodiments, the signal from the ambient pressure sensor 46 may be received by the ECU 38 .
[0027] For a diesel engine or other prime mover in combination with a positive displacement compressor, power is roughly proportional to speed for constant discharge pressures at constant ambient pressure. Because speed and power are related, the maximum rated power output may be based upon a fixed RPM limit for a nominal or standard ambient atmospheric condition. Alternatively, the maximum rated power may be based upon a sliding scale RPM limit that varies with ambient atmospheric pressure. A database or algorithm for determining an RPM limit at an ambient atmospheric pressure can be provided.
[0028] Thus, the invention provides, among other things, a new fluid compressor and method of operating a fluid compressor. Various features and advantages of the invention are set forth in the following claims.
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A fluid compression system includes a gaseous fluid compressor having a fluid inlet and a compressed fluid discharge, a prime mover coupled to the gaseous fluid compressor in driving relation, and a demand sensor positioned to measure a compressor demand and output a demand signal. An engine control unit is coupled to the prime mover and is operable to measure prime mover speed and prime mover power output. The engine control unit sets a variable maximum rated speed that maintains the engine power below a predetermined limit. A compressor controller unit is arranged to receive the demand signal and vary an operating speed based in part upon the demand signal. The operating speed is limited to the maximum rated speed set by the engine control unit.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to multiple access communication systems and in particular it relates to dynamic resource allocation in time division multiple access systems.
[0003] 2. Description of Related Art
[0004] In Multiple access wireless systems such as GSM, a number of mobile stations communicate with a network. The allocation of physical communication channels for use by the mobile stations is fixed. A description of the GSM system may be found in The GSM System for Mobile Communications by M. Mouly and M. B. Pautet, published 1992 with the ISBN reference 2-9507190-0-7.
[0005] With the advent of packet data communications over Time Division Multiple Access (TDMA) systems, more flexibility is required in the allocation of resources and in particular in the use of physical communication channels. For packet data transmissions in General Packet Radio Systems (GPRS) a number of Packet Data CHannels (PDCH) provide the physical communication links. The time division is by frames of 4.615 ms duration and each frame has eight consecutive 0.577 ms slots. A description of the GPRS system may be found in (3GPP TS 43.064 v5.1.1). The slots may be used for uplink or downlink communication. Uplink communication is a transmission from the mobile station for reception by the network to which it is attached. Reception by the mobile station of a transmission from the network is described as downlink.
[0006] In order to utilise most effectively the available bandwidth, access to channels can be allocated in response to changes in channel conditions, traffic loading, Quality of Service and subscription class. Owing to the continually changing channel conditions and traffic loadings a method for dynamic allocation of the available channels is available.
[0007] The amounts of time that the mobile station receives downlink or transmits uplink may be varied and slots allocated accordingly. The sequences of slots allocated for reception and transmission, the so-called multislot pattern is usually described in the form RXTY. The allocated receive (R) slots being the number X and the allocated transmit slots (T) the number Y.
[0008] A number of multislot classes, one through to 45, is defined for GPRS operation and the maximum uplink (Tx) and downlink (Rx) slot allocations are specified for each class.
[0009] In a GPRS system, access to a shared channel is controlled by means of an Uplink Status Flag (USF) transmitted on the downlink to each communicating mobile station (MS). In GPRS two allocation methods are defined, which differ in the convention about which uplink slots are made available on receipt of a USF. The present invention relates to a particular allocation method, in which an equal number “N” of PDCH's, a “PDCH” representing a pair of uplink and downlink slots corresponding to each other on a 1-1 basis, are allocated for potential use by the MS. The uplink slots available for actual use by a particular mobile station sharing the uplink channel are indicated in the USF. The USF is a data item capable of taking 8 values V0-V7, and allows uplink resources to be allocated amongst up to 8 mobiles where each mobile recognises one of these 8 values as ‘valid’, i.e. conferring exclusive use of resources to that mobile. A particular mobile station may recognise a different USF value on each of the slots assigned to that mobile station. In the case of the extended dynamic allocation method, for example, reception of a valid USF in the slot 2 of the present frame will indicate the actual availability for transmission of transmit slots 2 . . . N in the next TDMA frame or group of frames, where N is the number of allocated PDCHs. Generally for a valid USF received at receiver slot n, transmission takes place in the next transmit frame at transmit slots n, n+1 et seq. to the allocated number of slots (N). For the extended dynamic allocation method as presently defined these allocated slots are always consecutive.
[0010] The mobile station is not able instantly to switch from a receive condition to a transmit condition or vice versa and the time allocated to these reconfigurations is known as turnaround time. It is also necessary for the mobile station, whilst in packet transfer mode, to perform neighbourhood cell measurements. The mobile station has continuously to monitor all Broadcast Control Channel (BCCH) carriers as indicated by the BA(GPRS) list and the BCCH carrier of the serving cell. A received signal level measurement sample is taken in every TDMA frame, on at least one of the BCCH carriers. (3GPP TS 45.008v5 10.0). The turnaround and measurement times guaranteed by the network for a mobile station depend on the multislot class to which the mobile claims conformance (3GPP TS 45.002v5.9.0 Annex B).
[0011] The neighbour cell measurements are taken prior to re-configuration from reception to transmission or prior to re-configuration from transmission to reception.
[0012] A mobile station operating in extended dynamic allocation mode presently must begin uplink transmission in the Tx timeslot corresponding to the Rx timeslot in which the first valid USF is recognised. That is to say that there is a fixed relationship in the timing of the downlink allocation signalling and subsequent uplink transmission. Owing to the physical limitations of single transceiver mobile stations some desirable multislot configurations are not available for use.
[0013] These restrictions reduce the availability of slots for uplink transmissions thereby reducing the flow of data and the flexibility of response to changing conditions. There is a need therefore to provide a method with which to enable the use of those multislot configurations currently unavailable for Extended Dynamic Allocation.
SUMMARY OF THE INVENTION
[0014] It is an object of this invention to reduce the restrictions affecting extended dynamic allocation with minimal effect on the existing prescript. This maybe achieved by altering the fixed relationship in the timing of the downlink allocation signalling and subsequent uplink transmission for certain classes of mobile station.
[0015] In accordance with the invention there is a method for controlling uplink packet data transmissions and a mobile station operating in accordance with the method as set out in the attached claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] An embodiment of the invention will now be described with reference to the accompanying figures in which:
[0017] [0017]FIG. 1 illustrates the GPRS TDMA frame structure showing the numbering convention used for uplink (UL) and downlink (DL) timeslots;
[0018] [0018]FIG. 2 illustrates a prior art 4 slot steady state allocation R 1 T 4 ;
[0019] [0019]FIG. 3 illustrates a 5 slot steady state allocation R 1 T 5 prohibited in the prior art;
[0020] [0020]FIG. 4 illustrates a 5 slot steady state allocation R 1 T 5 enabled by the method of the present invention;
[0021] [0021]FIG. 5 illustrates a shifted USF applied to a class 7 MS with 3 uplink slots allocated;
[0022] [0022]FIG. 6 illustrates a class 7 MS with 2 uplink slots allocated;
[0023] [0023]FIG. 7 is a flow diagram for the implementation of shifted USF in a mobile station;
[0024] [0024]FIG. 8 illustrates a transition from one uplink slot to five uplink slots for a class 34 MS; and
[0025] [0025]FIG. 9 illustrates a transition from four to five uplink slots for a class 34 MS.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] In this embodiment, the invention is applied to a GPRS wireless network operating in accordance with the standards applicable to multislot classes.
[0027] In FIG. 1 the GPRS TDMA frame structure is illustrated and shows the numbering convention used for uplink (Tx) and downlink (Rx) timeslots. It should be noted that in practice Tx may be advanced relative to Rx due to timing advance (TA), although this is not shown in the illustration. Thus in practice the amount of time between the first Rx and first Tx of a frame may be reduced a fraction of a slot from the illustrated value of 3 slots due to timing advance.
[0028] Two successive TDMA frames are illustrated with downlink (DL) and uplink (UL) slots identified separately. The slot positions within the first frame are shown by the numerals 0 through to 7 with the transmission and reception slots offset by a margin of three slots. This is in accordance with the convention that that the first transmit frame in a TDMA lags the first receive frame by an offset of 3 (thus ordinary single slot GSM can be regarded as a particular case in which only slot 1 of transmit and receive is used).
[0029] The remaining figures conform to the illustration of FIG. 1 but the slot numbering has been removed for extra clarity. The shaded slots are those allocated for the particular states and the arrowed inserts indicate the applicable measurement and turnaround intervals. The hashed slots indicate reception of a valid USF and the timeslot in which that USF is received. As mentioned above, constraints are imposed by the need to allow measurement and turnaround slots and the prescript for these in 3GPP TS 45.002 Annex B limits dynamic allocation as shown in table 1.
TABLE 1 Maximum Minimum number of Multislot number of slots slots class Rx Tx Sum T ta T tb T ra T rb 7 3 3 4 3 1 3 1 34 5 5 6 2 1 1 1 39 5 5 6 2 1 1 + to 1 45 6 6 7 1 1 1 to
[0030] T ta is the time needed for the MS to perform adjacent cell signal level measurement and get ready to transmit.
[0031] T tb is the time needed for the MS to get ready to transmit
[0032] T ra is the time needed for the MS to perform adjacent cell signal level measurement and get ready to receive.
[0033] T rb is the time needed for the MS to get ready to receive
[0034] It should be noted that in practice the times T ta and T tb may be reduced by a fraction of a slot due to timing advance. t o is 31 symbol periods timing advance offset
[0035] With reference to FIG. 2, a steady state single downlink and 4 uplink slot allocation for a class 34 mobile station is illustrated. The turnaround and measurement periods for this class are shown in table 1 as Tra, Trb and Ttb each having one slot and Tta having two slots. These periods can be accommodated for this allocation when a valid USF is received in time slot 0 .
[0036] When the allocation of uplink slots extends to five, however, a constraint arises as indicated in the illustration of FIG. 3 which is for a class 34 mobile station with an allocation of one downlink and five uplink slots.
[0037] The constraint occurs at the position indicated by ‘A’ because no time is allowed for the changeover from transmit to receive (Trb). In the downlink time slot 0 a valid USF is received and the following two slots provide for Tta. In accordance with the invention, for this embodiment the mobile has uplink slots assigned in the usual way, through the use of USF_TN 0 . . . USF_TN 7 Information Elements in Packet Uplink Assignment and Packet Timeslot Reconfigure messages. The network sends the USF, however, for both first and second assigned timeslots on the downlink PDCH associated with the second assigned timeslot.
[0038] Considering by way of example a class 34 MS with an assignment of 5 uplink slots (TN 0 -TN 4 ) as discussed above where the network sends USF_TN 0 on timeslot 1 rather than timeslot 0 . This arrangement is illustrated in FIG. 4 where it can be seen that slots marked ‘B’ and ‘C’ provide for turnaround times Tra and Trb respectively.
[0039] An allocation by the network of 4 uplink slots to the MS will be signalled by the sending of USF_TN 1 on timeslot 1 . The characters of the two signals USF_TN 0 and USF_TN 1 must differ and must be distinguishable by the mobile station.
[0040] It is not necessary to add extra information elements to indicate when the Shifted USF mechanism is to be used, as it may be made implicit in the timeslot allocations for the particular multislot class of the mobile station. Therefore no increase in signalling overhead would be required.
[0041] With reference to FIG. 5, another example of an allocation enabled by implementation of a shifted USF is illustrated in FIG. 5. The application is a class 7 MS with three uplink slots allocated. The USF on downlink slot 1 allocating the 3 uplink slots indicates that the first uplink slot available is uplink slot 0 rather than the usual slot 1 . This provides for the Ttb and Tra periods (as required by table 1) and as indicated in FIG. 5 at D and E respectively. The allocation would not previously have been available for want of a sufficient period for Tra.
[0042] The 2 slot allocation illustrated in FIG. 6 reverts to normal operation i.e. the USF is not shifted. There are no physical constraints in normal allocations for this 2 slot arrangement of FIG. 6 and the standard USF in time slot 1 allocates uplink slots beginning with uplink slot number 1 .
[0043] Alternatively it may be convenient to apply positive signalling of the shift in position of the uplink allocation and an implementation of a shifted USF in a mobile station operating extended dynamic allocation is illustrated in FIG. 7. It should be noted that the indication ( 2 ) in FIG. 7 may be explicit (i.e. extra signalling) or implicit (automatic for particular multislot class configuration). With reference to FIG. 7, the mobile station receives at 1 an assignment of uplink resources and USF's from the network. If at 2 , an indication to use a shifted USF is detected then, for the first USF, the second downlink slot is monitored ( 3 ) otherwise the first downlink slot is monitored ( 4 ). In either case, when a valid USF has been received at 5 then uplink transmissions are initiated in the first uplink slot from the mobile station ( 6 ). When no valid USF has been received at 5 then the second downlink slot is monitored for a second USF at 7 and if valid ( 8 ) then uplink transmissions are initiated in the second uplink slot ( 9 ).
[0044] In the examples illustrated in FIGS. 2 to 6 the allocations are steady state such that the allocations shown are maintained from frame to frame. The invention is not restricted to steady state allocations and may be applied also to control of uplink resources that change from one frame to another.
[0045] Examples of transitions are illustrated in FIGS. 8 and 9. These figures each represent four consecutive frames but have been split for presentation.
[0046] [0046]FIG. 8 illustrates the transition from one uplink slot allocation to five uplink slots allocation, for a Class 34 mobile. The first (top) two frames show steady state operation with one slot and the next (bottom) two frames show the transitional frames. For this transition the slot location of the USF is changed.
[0047] [0047]FIG. 9 illustrates the transition from four uplink slots to five uplink slots, for a Class 34 mobile. The first two frames show steady state operation with four slots and the next two frames show the transitional frames. For this transition the USF slot location is constant but the value of the USF is changed.
[0048] In order to implement the invention in GPRS for example a table (Table 2) may be constructed for a Type 1 MS to allow extended dynamic allocation using the principles below:
[0049] In the case of extended dynamic allocation it is desirable for the MS to be able to “transmit up to its physical slot limit”; specifically, the MS should be able to transmit the maximum number of slots possible according to the limitation of its multislot class, while continuing to receive and decode the USF value on exactly one slot and performing measurements. If it is not possible to define a multislot configuration which permits the MS to “transmit up to its physical slot limit” using T ra , but it would be possible by using T ta , then T ta shall be used.
[0050] If it is not possible to define a multislot configuration for extended dynamic allocation which permits the MS to “transmit up to its physical slot limit” but it would be possible by using the shifted USF mechanism, then shifted USF shall be used. In this case Tra will be used as first preference, but if this is not possible Tta will be used as second preference.
TABLE 2 T ra T ta Applicable Medium shall shall Multislot access mode No of Slots apply apply classes Note Uplink, 1-3 Yes — 1-12, 19-45 Ext. 4 No Yes 33-34, 2 Dynamic 38-39, 43-45 5 Yes — 34, 39 5 5 No Yes 44-45 2, 4 6 No Yes 45 5 Down + up, d + u = 2-4 Yes — 1-12, 19-45 Ext. d + u = 5, d > 1 Yes — 8-12, 19-45 Dynamic d = 1, u = 4 No Yes 30-45 2 d + u = 6, d > 1 Yes 30-45 2,3 d = 1, u = 5 Yes 34, 39 5 d + u = 7, d > 1 No Yes 40-45 2, 4 d = 1, u = 6 No Yes 45 5
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A method for control of packet data transmissions in a TDMA wireless network to provide for additional choices in the allocation of communication channels. The fixed relationship in the timing of the downlink allocation signalling and subsequent uplink transmission is altered for certain classes of mobile station to avoid physical constraints. Examples of variations in USF signalling in GPRS are given.
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CROSS-REFERENCE
This application is a continuation-in-part of my copending U.S. patent application Ser. No. 185,339 filed Sept. 8, 1980.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to retractable mechanisms and supports for receptacles associated therewith, including chain and sprocket type mechanisms and waste receptacles for use in desks, cupboards, and other areas.
2. Description of the Prior Art
Receptacles used for storage or waste are frequently located in the corner of an office or work area. Such receptacles usually have a relatively short period of usage during the work day and are often inconveniently located or positioned so that they are difficult to empty or clean. Although such receptacles are necessary for occasional use, they are nevertheless often an obstruction when not in use.
It has been proposed in the past to use the space between the legs of a desk, or under cupboards, and in similar recesses, to locate a waste receptacle. However, this positioning of the receptacle makes it difficult for depositing waste therein and for removing the receptacle for emptying on a daily or weekly basis. My earlier U.S. Pat. No. 4,111,506 for carrying a wastebasket or similar item into and out of a recess, for example, a desk or a cupboard, was one form of a solution to the problem of positioning a wastebasket conveniently.
My co-pending U.S. patent application Ser. No. 185,339 shows an improved retractable scissors tong mechanism for use with wastebaskets and the like. Development of this type of invention has always been directed toward reducing the amount of pressure required to move the receptacle into and out of a recess. Research on such devices has also been directed toward decreasing the cost of such devices and facilitating the installation in a desk recess or cupboard.
The devices of my previous patent and patent application are a vast improvement over the practice of merely positioning a wastebasket in an inconvenient spot, but they do not include sufficient means for adjustment of the device to various recesses, door openings, and other dimensions of desks, cupboards, and the like.
SUMMARY OF THE INVENTION
The present invention overcomes the problem associated in the prior art with positioning of containers and is an improvement over my previous inventions. By my present invention, I have provided an apparatus for moving a container to various positions between the front and rear of a housing in a desk, cupboard, or similar item having a housing large enough for the container. I have also provided an apparatus which is adaptable to various environments in which it may be positioned. Finally, the device of the present invention is easily mounted in a very sturdy manner to either a cupboard, desk, or the like.
I have provided a carrier arm connected at one end to a housing and at its other end to a receptacle support such as a flat platform or support hook. In connection therewith, I have provided various means connected to the support for maintaining the orientation of the support relative to the housing at the various rotational positions of the carrier arm. As the carrier arm rotates from its position within a cupboard or desk to a position exposing the receptacle support and receptacle attached thereto, the orientation of the receptacle remains in the same relative position to facilitate depositing waste therein. Thus, a wastebasket or other container is not inconveniently oriented or tipped at the various rotational positions of the carrier arm. This orientation of the support and a receptacle carried thereby also facilitate the use of the device in relatively close spaces, such as small cupboards. The arc of the support and receptacle is reduced because of the consistent orientation during rotation from a recessed to an exposed position. This particular aspect of the invention is especially important for positioning containers in a small cupboard.
It should be realized, of course, that the device of the present invention is useful for items other than simple wastebaskets and containers. For example, the support of the device may be used to carry a box of laundry detergent, a bottle of chemicals, or any other carrier of supplies and parts, so long as the receptacle or other item is sufficiently affixed to the receptacle support according to the needs of the material carried.
Operation of the device is effected with an actuator rod. The actuator rod is connected at one end to the carrier arm. At its other end, the actuator rod is either exposed to a person's grip for pushing and pulling the rod or attached to a door or the like. In the latter situation, the opening of the door in the normal manner moves the actuator rod which in turn moves the carrier arm and the platform rotatably attached thereto. This feature of the invention is especially important for positioning a receptacle support in a cupboard or the like.
In a first embodiment of the invention, the means for maintaining the orientation of the receptacle support and container associated therewith comprises a chain and sprocket mechanism. The sprockets are located one at the point of attachment of the carrier arm in the housing and the other at the receptacle support. A chain, such as a linked ball chain, is drawn around the two sprockets tightly. When the carrier arm is rotated by the actuator rod, the chain pays off from one side of each sprocket and proceeds onto the other side of each sprocket. The sprocket attached to the receptacle support rotates about one end of the carrier arm to maintain the same relative orientation of the receptacle support with respect to the housing in which the device is mounted. A partial sprocket drive spring-loaded ball chain can take a significant misalignment of the sprockets without affecting the load on the device.
Conveniently, the carrier arm is formed as an elongated straight middle section having two opposite ends bent perpendicular thereto. These two opposite ends of the carrier arm form the axes of rotation for the device. The end of the carrier arm where the device is mounted to a housing rotates in a manner allowing the carrier arm to move through its arc. The other end of the carrier arm is suitably mounted in a bearing which allows the receptacle support to rotate thereabout.
Of course, the sprockets could be of different a diameter. This would cause the platform to rotate somewhat relative to the cabinet, when moved.
In another embodiment of the invention, the orientation maintaining means comprises a pair of hubs which replace the sprockets of the previously described embodiment. One hub is associated with one end of the carrier arm which is mounted to the housing. This first hub has a surface extending horizontally therefrom. The second hub is mounted to the receptacle support in the same manner as was described for the sprocket. Also, the carrier arm has an elongated central portion and two perpendicular end portions in the manner described above. However, no sprocket indentations are required on the hub and no chain is passed around the sprockets.
Instead of the chain and sprocket mechanism, the support receptacle has means for attaching an orientation arm which extends from the receptacle support to the horizontally extending surface which is attached to the first hub. This orientation rod is rigid and connects to the horizontally extending surface attached to the first hub.
The orientation rod is of a length designed to facilitate maintenance of the orientation of the receptacle support throughout the arc of rotation of the carrier arm. Thus, the orientation rod also swings about an arc, but from an axis at its point of connection to the horizontally extending surface. Thus, the orientation rod operates to exert a force at its point of attachment at the receptacle support. That force maintains the orientation of the receptacle support and any container associated therewith throughout the movement of the receptacle support. Of course, the receptacle support is again moved by the actuator rod which is connected to the carrier arm.
The end of the actuating rod is either conveniently located for gripping or is attached to a cupboard door or the like. The actuating rod may be attached at any convenient point along the carrier arm. However, it is preferable to attach the rod to the carrier arm at a point approximately midway therealong. In this manner, the actuator rod does not need to be moved to a great extent in order to move the carrier arm throughout its designed arc of rotation. My tests have shown that attachment of the actuator rod can be made very close to that end of the carrier arm closest to the housing, without greatly increasing the amount of pressure required to operate the device. Of course, as the actuator rod is attached farther from the housing, the moment of force to actuate the device becomes less, but the actuator rod must be moved a greater distance.
Various types of clamps and other known components may be used to attach the actuator rod to the carrier arm.
In a preferred form of either embodiment of the invention, the device is made adjustable by providing a mount at the housing wall such that the carrier arm is elevated slightly above or below the horizontal during most of its arc of rotation. Also, the mount for the end of the carrier rod adjacent the housing can be provided with a screw or similar adjustment device to vary the angle of the carrier arm relative to the horizontal.
An additional component may be associated with the device where it is mounted in a cupboard having a door. This component comprises an attachment surface at the door of the cupboard. The attachment surface has a series of holes or the like which allow connection of the actuator rod in any of the series of holes. Thus, the travel of the carrier arm can be limited or expanded by moving the point of attachment of the rod to the door.
Preferably, the receptacle support can be a hook or hanger fitted to be received in the support hole of a wastebasket. On the other hand, where the device is used in a cupboard or the like, the receptacle support may be a platform suitably shaped for holding any of various size containers or similar items.
Where the device is used in the environment of a desk recess, a stop may be provided on the push rod to limit the rotation of the carrier arm out from the rotation of the desk.
Testing indicates that, using bearings of polytetrafluoroethylene or nylon and a small ball chain embodiment of the invention, only two pounds of pressure is required to rotate the carrier arm which supports a thirteen pound load thereon or suspended therefrom. This test was performed with the actuator rod at a relatively intermediate position along the carrier arm. By proper adjustment, the pressure can be reduced to less than one pound.
In a universal cabinet embodiment of the invention a centering hook is used with a basket having an eyelet received on the hook. The hook is formed so that the basket or container, by its own weight, naturally centers on and aligns with the cabinet opening. The eyelet is preferably of metal type positioned around an aperture in the basket or container.
It is, therefore, an object of the present invention to provide a device for moving a receptacle into and out of the recess of a housing wherein the device requires only slight pressure to operate even with relatively heavy loads.
It is also an object of the present invention to provide a receptacle moving device which has adjustable features for mounting and operating the device.
It is also an object of the present invention to provide a device for moving a receptacle into and out of the housing of a desk, cupboard, or similar recess while maintaining the orientation of the receptacle and its support with respect to the recess housing.
It is also an object of the present invention to provide a receptacle moving support which is easily mounted to a recess housing and may also be adjustably positioned at the mounting.
It is also an object of the present invention to provide a device for moving a receptacle into and out of a housing recess wherein the receptacle is either supported on a base or depends from a hanger.
It is also an object of the present invention to provide a device which facilitates the use of wastepaper baskets and similar items in offices and industry, thereby saving office floor space and making the office or industrial area more attractive.
It is also an object of the present invention to provide a receptacle carrying device which makes better use of cupboard space, floor space, office space, and industrial work space.
It is also an object of the present invention to provide a device which is suitable for carrying any of various containers and other items between recessed and exposed positions in a desk, cupboard, or the like.
It is also an object of the present invention to provide an orientation arm, chain and sprocket mechanism, belt drive mechanism, or similar device for maintaining the orientation of a waste receptacle or similar item relative to the housing in which it is used during the rotation of the device from a recessed to an exposed or forward position.
These and other objects of the present invention will be better understood by a review of the following description when read in conjunction with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following description and the attached drawings, like reference numerals refer to like characters throughout the specification and the several views of the drawings, in which:
FIG. 1 is an elevated view, partly in section, showing the device of the present invention with a support base and using a chain and sprocket mechanism in a cupboard environment;
FIG. 2 is an overhead perspective view of the device of the present invention with additional rotational positions of the device shown in phantom;
FIG. 3 is a sectional view through the device shown in FIG. 1;
FIG. 4 is a front view of the chain and sprocket embodiment of the present invention shown with a receptacle hanger in a desk environment;
FIG. 5 is a partial sectional view of the universal joint of the receptacle support hanger of the invention;
FIG. 6 is an overhead view of the invention using the orientation rod embodiment;
FIG. 7 is a perspective view of the device shown in FIG. 6 with some elements shown in phantom;
FIG. 8 is a top view of the orientation rod embodiment of the present invention as mounted in a desk housing having an actuator rod with a knob for use as a stop;
FIG. 9 is a perspective view, partly in section, showing the orientation rod embodiment of the present invention with a basket carrier suspended from the universal joint (in phantom); and
FIG. 10 is a side view of a carrier arm of the invention having a threaded hook for use with containers to be suspended under the top wall of the housing, with the hook shown 90° out of phase for clarity.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1-4 in general, and specifically to FIG. 1, the chain and sprocket embodiment 10 of the invention is thereshown in the environment of a cupboard housing having a side wall 12 and door 13 hinged thereto by hinge 15. The device 10 is mounted to wall 12 by bracket 14 which has a base plate 16 attached to wall 12 by screws 18. A rotation bracket 20 is affixed to the mounting bracket 14 such as by welds 22 (FIG. 3). A carrier arm 24 has a first end 26 perpendicular thereto and rotationally mounted in bracket 20. A combination collar and bushing 28 supports the arm 24 in bracket 20 and a ball chain type sprocket 30 is screwed to the lower horizontal portion 32 of bracket 20. The screws 34 securing sprocket 30 on the end 26 of the carrier arm 24 are more clearly shown in FIG. 3.
Still referring to FIG. 1 specifically as well as to FIGS. 2-4 in general, a ball chain 36 is thereshown as wrapped about the sprocket 30 in a manner so that it is elevated somewhat over the carrier arm 24. A second sprocket 38 is mounted on an opposite perpendicular end 40 of the carrier arm 24 by screws 42. Snap ring 41 secures end 40 in place over bearing surface/bushing 39. The chain 36 is fitted onto sprocket 38 in the same manner as for sprocket 30. The molded sprocket may be formed with indentations along only a part of the circumference of the sprocket thus saving some machining costs. This is possible since a portion of the sprockets are never contacted by the ball chain. The sprockets are conveniently formed of three-quarter inch aluminum.
As more clearly shown in FIG. 3, the other end 40 of the carrier arm 24 is journalled within a combination collar and bushing 44 so that bushing 44 is rotatable about end 40. Sprocket 38 is, however, attached to support surface 46 by screws 42.
Thus, end 26 is rotatable in bracket 20 and the sprocket 38 with attached support surface 46 is rotatable about end 40 of carrier arm 24.
A wastebasket 50 or similar container is shown in phantom in FIG. 1. An analogous wastebasket 52 is shown in FIG. 4 of the drawings.
Door 13 has a bracket 54 attached thereto such as by welding. Metal screws or wood screws may also be used depending on the material of the doors. Bracket 54 has a series of holes along the top thereof such that an actuator rod 56 may be attached with its depending tip 58, to the door 13 in any of the various holes. Actuator rod 56 is also attached to a clip or bracket 60. Alternatively, the actuator rod 56 could be attached directly to the carrier arm 24. However, the bracket 60 is made so that it is adjustable along the length of carrier arm 24. This adjustment allows for a change in the moment of force required to rotate carrier arm 24 about its axis (connecting end 26). Thus, movement of adjustably securable bracket 60 along the length of carrier arm 24 varies the pressure required to close the cabinet door 13 and move the support 46 back into the recess of the housing.
Referring now more specifically to FIG. 2, the support surface 46 is thereshown in the environment of a small cupboard as seen from above and attached to side wall 12. Actuator rod 56 is shown as located in the outermost hole of the bracket 54. The cupboard door 13 and support platform 46 are shown in phantom in an intermediate position and in an open position for the cupboard. The edge 62 of platform 46 maintains a parallel orientation to wall 12 in all three of the positions shown in FIG. 2. This aspect of the invention is important for insuring that the proper access area to the container carried on support surface 46 is always toward the user when the cupboard is open. Of course, this aspect of the invention is especially important when a basket such as wastebasket 52 is hung in the environment of a desk, as shown in FIG. 4. Also, a box having an opening at one end only may also be positioned on the surface 46 so that the opening is always accessible.
As carrier arm 24 rotates about its axis (perpendicular end 26) in a counterclockwise direction as seen from above in FIG. 2, the support surface 46 also rotates about an axis (perpendicular end 40) but in a clockwise direction, counter to the rotation of the carrier arm. This action is caused by the chain and sprocket mechanism of the embodiment shown in FIGS. 1-4 and operates to maintain the position of the support surface and any receptacle carried thereon, in the same relative orientation with respective to the cupboard or other environment with which it is associated.
When a wastebasket 52 is suspended from the device 10 of the present invention in the environment of a desk 64 as shown in FIG. 4, the convenience of the basket is readily appreciated. A person sitting at the desk can merely pull the actuator arm out a small distance which operates to retrieve the wastebasket 52 from its most recessed position in the housing of the desk 64 to its forward position as shown in FIG. 4. Thus, without even looking beneath the desk, a person seated at the desk 64 can merely take an item of trash and deposit it in front of himself with very little effort. The basket 52 is then moved to its recessed position by merely pushing the actuator rod 56 back to the surface of the desk by means of knob 66.
Alternative to the particular embodiment shown in FIG. 4, the hub 69 may have a hook 80 extending horizontally therefrom as shown in FIG. 10, rather than a hanger descending directly beneath it. The hook 80 is usable in connection with a wastebasket which has a small hole formed therein to be received over the hook 80. The particular adaptation shown in FIG. 10 is of a universal cabinet design more suitable for use with an area beneath a kitchen sink or the like. Wastebaskets for use with the device in that particular adaptation have a metal eyelet or like attachment in a side wall of the basket to form an aperture for carrying the basket on the hook 80 which extends from the hub 69. The use of a hub 69 rather than a sprocket 68 is explained below.
The travel arm 24 of this universal cabinet embodiment preferably has adjustment means for varying the length thereof according to the cabinet in which it is used. A sleeve 25 has screw holes (not shown) to receive screws 27 therein. A series of screw holes (also not shown) is formed in the opposed sections 29 and 31 of arm 24 to receive screws 27. Thus, the overall effective length of arm 24 may be varied.
Bushing 86 allows free rotation of sprocket 69 around end 39.
Hook 80 is formed with means for centering and aligning a basket suspended thereon. Eyelet 200 is held against angled surface 202 of hook 80. The weight of the baskket 204 forces the top surface of side wall 206 to bear against the top of the relatively vertical surface 208 of hook 80, thereby centering basket 204 and aligning it according to a preset orientation while the basket is suspended at a normal angle A as shown in FIG. 10 due to the center of gravity of the basket. The preset orientation may be the square alignment of a rectangular shaped basket with the cabinet door opening, for example. So long as the bottom curve 210 of hook 80 is at the lowermost position possible, the basket will tend to orient square to the cabinet opening by the action of its own weight. Any other position places the eyelet farther up angled surface 202, which causes the eyelet and basket to descend and become reoriented with respect to the cabinet opening, and thereby align, by its own weight at the same height and same normal angle A due to center of gravity of basket.
The hook 80 has an externally threaded end 82 received in internally threaded bore 84 on carrier arm 24. Jam nut 83 or a wing nut may be used to position and hold hook 80. FIG. 5 shows an alternative hanger mechanism depending from a carrier arm 24. The arm 24 is in the inverted position in the same manner as shown for FIG. 4. The end 40 of the carrier arm 24 passes through the sprocket 68 and has a pin 72 which supports washer 74 to prevent end 40 from releasing the sprocket 68. A universal mechanism 81 is formed within the side walls of sprocket 68. The universal mechanism has a crosspiece 74 and another transverse crosspiece 76 therethrough so that it may freely rotate therein. The depending hook or hanger 70 is joined by means of a connector (not shown) to the crosspiece 76 so as to form a universal joint.
The operation of the chain and sprocket mechanism 10 will now be described briefly to give a better understanding of the rotation of the carrier arm 24 and support surface 46 of the invention such as shown in FIG. 2. With reference to FIGS. 1-3, opening of door 13 moves actuator rod 56 to bring the support surface 46 from the recess of the housing to its forward position. Bear in mind that sprocket 30 is affixed to bracket 32 by screws 34 and sprocket 38 is affixed to the support surface 46 by screws 48. Therefore, the carrier arm end 26 may rotate within the bearing 25 while the support surface 46, sprocket 38, and bearing surface 39 rotate about the opposite end 40 of the carrier bar 24. The rotation of the sprocket 38 and support surface 46 is caused by chain 36.
As door 13 is opened, chain 36 pays off from sprocket 30 at the indentations 19 (FIG. 1) while additional ball links of chain 36 feed onto the previously open indentations 21 on the opposite side of sprocket 30. Meanwhile, sprocket 38 is caused to rotate in a clockwise direction as seen from above from FIG. 2, by the action of chain 36 paying onto the indentations of the sprocket near the door of the cupboard and paying off from the indentations in the sprocket 38 at the rear of the cupboard.
Another preferred embodiment of the present invention is also shown in FIGS. 6-9.
Referring now to FIG. 6, another embodiment of the invention is thereshown with similar components and also including a stationary idler arm or horizontally extending surface 100 which is locked in position with respect to cupboard 12. Also included in this embodiment is an orientation rod 102 which connects at the innermost end 104 of the support surface in a manner so that it may rotate freely therein. The opposite end 106 of the orientation rod 102 is attached to the support surface in a manner so that the support surface may rotate about the point of attachment 108. The point of attachment may be formed as any means suitably allowing motion of the platform between the recessed and extended positions.
A hub 110 is connected to the support surface 46 by screws 42 in the same manner as for the sprocket 38 shown in FIG. 1. However, hub 42 has no indentations for a chain or the like. Carrier arm 24 is connected to hub 42 in the same manner as for the sprockets described above. The opposite end 26 of the carrier arm 24 is similarly rotatably connected to a hub 112 which is mounted to the cupboard 12 as described for the chain and sprocket embodiment of the invention. The actuator rod 56 is shown as directly attached to carrier arm 24 in FIGS. 6-9.
Opening of door 13 causes rotation of carrier arm 24 as well as rotation of orientation rod 102. Thus, the support surface 46 maintains the same relative orientation with respect to the cupboard and its side wall 12 throughout the path of travel of the orientation rod 102 and carrier arm 104.
Once again, a bracket 54 is attached to door 13 so that the actuator rod 56 may be adjustably connected thereto. Furthermore, as shown in FIGS. 8 and 9, the carrier arm 24 may have additional holes 114 for variable attachment of the actuator rod 56 to the carrier arm 24.
Preferably, the orientation rod 102 has threaded ends for attachment and minor adjustment as shown in FIGS. 6-9.
The preferred mounting bracket shown in FIGS. 7 and 9 has an upper horizontal portion 116 and a lower horizontal portion 118 hinged and joined by a screw 120. Mounting bracket 122 has a flange 124 extending therefrom to receive screw 120 in the manner shown. Additionally, a screw 126 is provided through the lower section 118 of the mounting bracket. This screw may be adjusted to vary the pitch of the carrier arm with respect to the horizontal. Such an adjustment varies the amount of pressure required to operate the device.
FIGS. 8 and 9 show the device of the invention having a hanger 70. FIG. 9 shows the universal mechanism 81 as was described for FIG. 5. A support surface 47 is shown in FIGS. 8 and 9. This surface is provided merely for the connection of orientation rod 102 so as to maintain the relative orientation of hanger 70 and any container or other article suspended therefrom. Adjustment screw 126 is also shown in FIG. 9. Of course, a thumbscrew adjustment could be provided in some environments. A combination thrust lock and collar 128 is also used for a bearing surface at the various positions on the carrier arm, as was described for the chain and sprocket embodiment of FIGS. 1-4. A pitman arm or support surface 47 is connected to a hub 130 by screws 132 in the same manner as the attachment of sprocket 38 in FIG. 1.
FIG. 8 shows a knob 57 attached to actuator rod 56. The actuator rod 56 is bent at an angle to facilitate retrieval and replacement of the hanger 70 from the position shown in full lines to the phantom position. The small plate 134 at the front of a desk or other cabinet operates as a stop for the knob 57 on actuator rod 56. This limits the travel of the carrier arm 24 from within the recess of the housing shown in FIG. 8.
A slot 140 is formed in mounting bracket 112 so that the bracket may be adjustably mounted at various angles so as to vary the angle of the carrier arm relative to the horizontal. Thus, the bracket may be so mounted that the carrier arm moves either upwardly toward the rear of the cabinet or upwardly toward the front of the cabinet. This also allows for an adjustment to guard against oilcanning of side walls for metal cabinets and the like.
Although preferred embodiments of the present invention have been described and shown, it will be apparent to those skilled in the art that it is possible to vary certain aspects of the invention such as the type of materials used and the formation of the support surface for hanger, without departing from the scope or spirit of the invention as defined in the appended claims.
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A retractable basket carrier with chain and sprocket mechanism or travel bar mechanism. A mechanism is provided in the alcove of a desk or similar space in a cabinet to move a carrier from an inner hidden position to an extended position which accesses a wastepaper basket or similar item carried by or depending from the carrier. The mechanism may be installed on either side of the opening in the desk for left or right hand operation and is easily placed in position in the desk with a mounting bracket. An actuator mechanism is installed at the front of the desk for extending the carrier by swing arm movement and to provide a stop for the rearward movement of the carrier. Either a ball chain mechanism or a travel arm with hubs is used to move the carrier. A wastebasket or other item may be supported from the carrier by a universal joint and is moved between the extended and inward positions with only a slight amount of force upon the actuating mechanism. The orientation of the container remains constant relative to the desk throughout the rotation of the support arm connected to the carrier.
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FIELD OF THE INVENTION
This invention relates to a novel method for removing silane compounds from silane-containing exhaust gases.
BACKGROUND OF THE INVENTION
Exhaust gases which contain silane and must be subjected to cleaning are being produced today in many branches of industry, as for example in the production of silicon compounds, in the packing of silicon compounds, in the production and bottling of silane-containing gas mixtures, and in the production of semiconductors.
Conventional methods of disposal, such as burning or washing in wash towers, present great problems with regard to their technical practice and the pollution of the environment. Burning them off causes the development of very fine silica which are hard to separate from the combustion gases. If chlorosilanes are contained in the exhaust, HCl and Cl 2 occur in the combustion gases, i.e., the burning must be followed by an additional exhaust treatment. If aqueous wash tower systems are used, problems occur due to silicification, and in the case of chlorosilanes acid waste water problems are encountered. Monosilane is but slowly hydrolyzed by water, so that an alkaline washing must be added afterwards.
OBJECT OF THE INVENTION
It is an object of the present invention to provide a method for the removal of silane compounds from silane-containing exhaust gases which does not have the aforementioned disadvantages. Other objects and advantages of the invention will become apparent a the description thereof proceeds.
DESCRIPTION OF THE INVENTION
The above object is achieved in accordance with the instant invention by reacting the silane compounds with a metal alcoholate solution to produce a tetraalkoxysilane.
In the process of the invention the silane compounds are completely converted into tetraalkoxysilane. The tetraalkoxysilane can be worked up by alkoxysilane manufacturers and marketed.
In practice, the alcoholic metal alcoholate solution is advantageously circulated through a packed column.
The method of the invention can be performed in countercurrent or in parallel flow. Preferably, the silane-containing exhaust gases are conducted countercurrently with respect to the metal alcoholate solution.
Preferably sodium methylate in methanol or sodium ethylate in ethanol is used as the metal alcoholate reactant in the method of the invention. The concentration of the metal alcoholate in the alcohol is preferably 5 to 30 wt.-%.
By means of the method of the invention the following silane compounds can be removed from exhaust gases:
SiH n X 4-n ; n=0-4, F, Cl, Br;
SiH n (OR) 4-n ; n=1-3, R=CH 3 , C 2 H 5 , C 3 H 7 ;
Si 2 H 6 and higher silanes, such as trisilane.
Preferably, the process is used in conjunction with exhaust gases containing monosilane and disilane. In the removal of silanes the reaction proceeds, for example, in accordance with the equation: ##STR1## The use of sodium methylate in methanol is especially cost effective.
If the exhaust gas contains only Si-H compounds, the reaction products obtained are only tetraalkoxysilane and hydrogen. Only the alcohol is consumed; the alcoholate has only a catalytic action. Thus, only the used-up alcohol and the alcoholate that escapes with the tetraalkoxysilane has to be replaced in the circulating solution.
The reaction of the alkoxysilanes of the above-mentioned general formula with the alcohol follows a course under the catalytic action of the metal alcoholate which is similar to the reaction of the silanes according to the above equation, with the formation of tetraalkoxysilane and hydrogen.
The halogenated silanes that occur in silane-containing exhaust gases are usually tetrachlorosilane, trichlorosilane, dichlorosilane and monochlorosilane. The reaction for the removal of these silanes takes place, for example, according to the equation:
SiH.sub.2 Cl.sub.2 +2 NaOCH.sub.3 +2 CH.sub.3 OH→Si(OCH.sub.3).sub.4 +2 H.sub.2 +2 NaCl.
Halogenated silanes yield a metal halide as an additional reaction product. In this case, alcoholate is consumed in addition to the alcohol, corresponding to the chlorine content of the silane.
BRIEF DESCRIPTION OF THE DRAWING
The schematic representation in the accompanying drawing of an apparatus for the performance of the novel method will, together with the examples, serve to further illustrate the invention.
Referring now to the drawing, the alcoholic metal alcoholate solution is delivered through feed line 7 and pump 6 to the packed column 1. The silane-containing exhaust gas is introduced, for example, through line 4. In this embodiment, therefore, the silane-containing exhaust gas flows countercurrently to the alcoholate solution. The cleaned gas leaves the column through the exhaust gas cooler 3 and the exhaust gas line 5. A coolant with a temperature of, for example, -40° C. flows through the exhaust gas cooler. The system is blanketed with an inert gas, for example nitrogen, through line 10. In the exhaust gas cooler 3 any solvents and/or alkoxysilane entrained by the inert gas are condensed. The alcoholic metal alcoholate solution is collected in tank 2, which also serves as a settling tank for NaCl in the treatment of chlorosilane-containing exhaust gases and as a collector for the condensate from the exhaust gas cooler The alcoholic metal alcoholate solution is circulated through outlet 9, pump 6 and line 11. Depending on the silane compounds present in the exhaust gas, the alcohol or the alcoholate solution that is consumed is replaced. The spent alcoholate solution, the sodium chloride that has formed, and other liquid or solid components that are formed by reaction or condensation are drained off through draincock 8.
The reactions in the following Examples 1 to 3 were performed at a pressure of about 1 bar and at room temperature. It is also possible, however, to perform the process of the invention at other pressures and temperatures.
The following examples illustrate the present invention and will enable others skilled in the art to understand it more completely. It should be understood, however, that the invention is not limited solely to the particular examples given below.
EXAMPLE 1
The entire apparatus was first flushed out with nitrogen. A 20 to 30 weight-percent methanolic sodium methylate solution was then fed in through inlet 7. After starting up pump 6 and exhaust cooler 3, an exhaust gas containing chlorosilane was introduced through line 4. Phenolphthalein was added as an indicator to the methylate solution. Incipient decoloration in the packed column 1 indicated that the sodium methylate solution was exhausted. Part of the spent solution was then let out through draincock 8 together with the precipitated sodium chloride. The liquid supply to pump 6 was assured through outlet 9. The corresponding amount of fresh solution was added through inlet 7. It was not necessary to shut down the apparatus to do this. Gas-chromatographic analysis of the gas leaving exhaust line 5 showed that it contained no chlorosilane. The apparatus was constantly operated in an atmosphere of nitrogen.
EXAMPLE 2
The entire apparatus was first flushed out with nitrogen. Commercial 5 to 30 wt-% methanolic sodium methylate solution was fed in through inlet 7. After pump 6 and gas cooler 3 had been started up, exhaust gas containing monosilane was introduced through line 4. When the alcoholate solution was used up, a part of the spent solution was let out, as in Example 1, and fresh solution was added. Again, the apparatus did not need to be shut down. Gas-chromatographic analysis of the gas leaving exhaust line 5 showed that it contained no monosilane.
The apparatus was constantly operated in an atmosphere of nitrogen.
EXAMPLE 3
First the entire apparatus was flushed out with nitrogen. Through inlet 7, commercial 5 to 30 wt-% ethanolic sodium ethylate solution was fed in. After starting pump 6 and exhaust cooler 3, exhaust gas containing monosilane was introduced through line 4. When the alcoholate solution was used up, part of the old solution was let out as in Example 1, and fresh solution was added. Again, the apparatus did not need to be shut down. Gas-chromatographic analysis of the gas leaving exhaust line 5 showed that it contained no monosilane.
The apparatus was constantly operated in an atmosphere of nitrogen.
EXAMPLE 4 (For comparison)
600 ml of a saturated solution of KOH in methanol were introduced into a one-liter three-necked flask equipped with a gas introduction tube, stirrer and reflux condenser. A nitrogen stream containing trichlorosilane was passed through the solution, while stirring. Immediately, a white solid formed, with frothing. The chlorosilane reacted completely, but the greasy consistency of the suspension which formed would interfere with continuous operation of the apparatus as described in Examples 1 to 3 in a reliable and reproducible manner. Furthermore, difficulties were encountered in getting the product into a form suitable for disposal.
While the present invention has been illustrated with the aid of certain specific embodiments thereof, it will be readily apparent to others skilled in the art that the invention is not limited to these particular embodiments, and that various changes and modifications may be made without departing from the spirit of the invention or the scope of the appended claims.
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A method for removing silane compounds from exhaust gases containing silanes comprises treating the silane containing gas with a metal alcholate in alcoholic solution to form a tetraalkoxysilane.
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This application is a continuation of application Ser. No. 383,394, filed Jul. 20, 1989 now abandoned.
BACKGROUND
1. Field of the Invention
This invention relates generally to a plant for dosing and mixing different substances, and more particularly to apparatus for the production of perfumes.
2. Discussion of Related Art
In preparing and developing certain perfume formulations, individual perfumes have to be mixed together in exact doses, particularly for test purposes. The individual perfumes are stored separately from one another in reservoirs or the like. To prepare a perfume mixture, the particular perfumes required are taken manually from the individual reservoirs. The individual quantity for each perfume can be determined by weighing or by using a corresponding measuring cup. The desired perfume is then prepared by mixing the individual perfumes in a mixing vessel.
However, this procedure is very complicated because one operator is required for the preparation of each mixture. The individual components must be laboriously blended together by weighing or the like. Human errors may occur due to inaccurate dosing or even incorrect dosing.
3. Summary of the Invention
With the problems in the prior art in mind, the present invention provides a solution which enables different substances, particularly liquids, to be accurately dosed and mixed without error, in an automated processing plant, in the absence of an operator.
According to the invention, this problem is solved by a plant including apparatus comprising an outlet dosing valve controlled by a control computer arranged on each reservoir above a line of mixing vessels, in combination with a mixing vessel designed to travel along the line of mixing vessels associated with each outlet dosing valve under computer control.
With a fully automatic plant designed in this way, any desired mixture can be prepared from substances contained in the reservoirs associated with the plant in the absence of operators. The necessary data, such as quantity and composition for the particular mixture, are fed into the control computer. Under the control of the control computer, a mixing vessel is brought, in successive order, beneath the corresponding outlet dosing valves of the reservoirs and filled with the particular quantity necessary by means of the outlet dosing valve (controlled by the computer) of the associated reservoir.
In one embodiment of the invention, an inert gas (nitrogen, for example) is fed under variable pressure to the reservoirs. This inert gas cushion in the reservoirs guarantees constant pressure conditions at the dosing valves, for providing reliable control of the particular quantities released.
It is of particular advantage in this regard for the mixing vessel to be arranged on a weighing unit connected to the control computer. In this manner, possible sources of error can be eliminated during dosing, because the particular quantity to be released from a particular reservoir is determined both by measurement of the throughflow volume at the outlet dosing valve, and by monitoring of the quantity released by the weighing unit. In addition, the consumptions of the various perfumes can be balanced by the weighing unit connected to the control computer.
To enable several mixtures to be automatically prepared continuously and successively in the plant or perfume factory according to the invention, the line of mixing vessels is preceded by a store of mixing vessels with a conveyor belt.
In another embodiment of the invention, a handling unit is arranged between the line of mixing vessels and the store of mixing vessels to transfer the mixing vessels from the store to the line. This embodiment is intended for cases where the conveyor belt of the store is not directly coupled with the line of mixing vessels.
In one particularly practical embodiment of the invention, each mixing vessel is provided with a code designed to be read by a scanner arranged at the end of the store of mixing vessels and connected to the control computer. In this way, the data of a perfume mixture can be read off by the control computer through coded formulation numbers. Individual mixture formulations may be fed into the computer through a terminal or, alternatively, computer-controlled series mixtures may even be prepared.
In one particularly preferred embodiment of the invention, the line of mixing vessels is in the form of a turntable with a weighing unit designed to travel in a circle. The dosing valves are preferably arranged in a circle with the radius of the weighing unit. This arrangement of the individual elements of the plant is particularly space-saving.
To obtain an even more compact arrangement, several dosing valves may be arranged together in groups.
Finally, in another embodiment of the invention, another store of mixing vessels with a conveyor belt is arranged at the end of the line of mixing vessels. An arrangement such as this is of advantage when mixtures are to be stored rather than used immediately, i.e. a whole series of mixtures can be prepared overnight, for example.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described by way of example in the following with reference to the accompanying drawings, in which like items are indicated by the same reference designation, wherein:
FIG. 1 is a flow chart of a plant or perfume factory of one embodiment of the invention;
FIG. 2 is a plan view of a line of mixing vessels in one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, in one embodiment of the invention, a fully automatic perfume factory or plant for dosing and mixing perfumes comprises a plurality of reservoirs 1 for storing different perfumes, only a few reservoirs being shown by way of example in the drawing. These reservoirs 1 are connected by lines 2 to an inert gas system 3, from which inert gas can be fed under variable pressure through valves 4, from inert gas containers 5 to the reservoirs 1. A constant pressure level is established in the reservoirs 1 by the inert gas cushion provided by the gas, such as nitrogen, for example.
Each reservoir 1 is connected by a line 6 to an electrically controlled outlet dosing valve 7. Each valve 7 is connected to and actuated by a control computer 8. In this manner, the valves 7 are computer controlled.
With references to FIG. 2, the individual outlet dosing valves 7 are preferably arranged in a circle 9 in a horizontal plane higher than that of the the juxtaposed line of mixing vessels 12 on conveyor 14. The mixing vessels 12 are successively and individually positioned on a weighing unit 11 on the outer end of turntable or rotatable arm 10, as described below. Rotatable arm 10 moves weighing unit 11, and an associated mixing vessel 12 in a circle under the circle of mixing valves 7, as will be described in greater detail below.
The line of mixing vessels 12 is preceded by a storage area 13 on conveyor belt 14 for mixing vessels 12 waiting to be filled. A handling unit 15 is used to transfer a mixing vessel 12 from the store 13 to the weighing unit 11 of the turntable or rotatable arm 10, at a loading/unloading position. The handling device 15 may be preceded by a scanner 16 which is designed to read codes on the mixing vessels 12 for the desired perfume mixtures as the latter moves towards the loading/unloading position. Scanner 16 is connected to the control computer 8.
The line of mixing vessels 12 is followed by another storage area 17 for filled mixing vessels 12 individually transported by the handling unit 15 onto conveyor 14. In the embodiment shown in FIG. 2, the first storage area 13 on the conveyor belt 14 is designed to circulate in such a way that after filling of mixing vessel 12, it becomes the second storage area 17 of mixing vessels on conveyor belt 14.
The dosing and mixing plant operation will now be described. First, a row of empty mixing vessels 12 arranged one behind the other is placed, for example, manually on the conveyor belt 14 in the storage area 13. The storage area 13 and/or mixing vessels 12 are provided with a code containing the desired mixture identification. The code on a mixing vessel 12 next to be used, is then read by the scanner 16 and fed into the control computer 8. Under the control of the computer, the handling unit 15 then takes up the particular mixing vessel 12 and transfers it from the conveyor belt 14 to the weighing unit 11 of the turntable 10. Depending on the desired mixture, the mixing vessel 12 is then moved via computer control under the circle 9 of dosing valves 7, by rotation of the turntable or arm 10 and brought under the particular outlet dosing valve 7 of the corresponding reservoir 1, where it is filled with the corresponding quantity of perfume by opening of the valve 7 and weighing by the weighing unit 11. In this manner, the turntable 10 successively moves the mixing vessel 12 under the necessary outlet dosing valves 7 of the particular reservoirs 1.
After one complete revolution of the turntable or arm 10 through 360°, the particular mixing vessel 12 now filled with the desired perfume formulation, is removed from the weighing unit 11 by the handling unit 15, and placed in the following storage area 17 of mixing vessels. To fill another mixing vessel 12, an empty mixing vessel 12 is again taken from the storage area 13 by the handling unit 15 and placed in the weighing unit 11 of the turntable or arm 10, and the process is repeated.
In summation of the preferred arrangement of apparatus and method of operation of the present perfume plant, further reference is made to FIGS. 1 and 2. Empty mixing vessels or containers 12 are placed successively on a generally L-shaped conveyor belt 14 in a storage area 13 before or upstream of a scanner 16. In this example, the conveyor belt moves in a counterclockwise direction, for moving each empty mixing vessel 12 past scanner 16. Scanner 16 reads coded information from each passing mixing vessel 12, and supplied a data signal to control computer 8 indicative of the perfume formulation associated with and to be dispensed into that particular container.
When such a mixing vessel 12 is moved via conveyor 14 to a loading/unloading position between handling unit 15 and weighing unit 11, computer 8 activates handling unit 15 to move the mixing vessel 12 onto the weighing unit 11. Note that the weighing unit 11 can be provided by conventional means. Also, the handling unit 15 can be provided by a conventional unit for moving individual containers 12 to and from the weighing unit 11.
Next, computer 8 activates turntable to rotate through 360°, and in doing so, to successively stop for positioning the mixing vessel on weighing unit 11 under an outlet dosing valve 7 associated with a reservoir 1 containing a necessary component of the perfume formula associated with the mixing vessel 12. The control computer 8 opens the associated valve 7 to dispense the required quantity of perfume component into the mixing vessel 12. Weighing unit 11 provides signals to the computer 8 indicative of the weight of mixing vessel 12 at any given time, for detecting when the necessary amount of perfume component has been received.
Control computer 8 then rotates turntable 10 to position mixing vessel 12 beneath the next dosing valve 7 associated with the next perfume component to be dispensed into mixing vessel 12. This process is continued until the mixing vessel 12 is so rotated through 360° and returned to its starting position, but now the mixing vessel is filled with various components necessary for its associated perfume formulation.
Control computer 8 activates handling unit 15 to remove the filled mixing vessel 12 from weighing unit 11, back onto conveyor belt 14. The computer 8 then activates conveyor 14 to move the filled mixing vessel 12 to a storage area 17 for filled ones of mixing vessels 12. Also, a new empty mixing vessel 12 is similarly moved into position between weighing unit 11 and handling unit 15, and the process is repeated for filling the new mixing vessel 12 with components necessary to its associated perfume formulation.
The invention is not confined to the embodiments shown by way of example in the drawing. Further embodiments of the invention are possible without departing from the basic concept. In particular, the configuration of the line of mixing vessels and the corresponding arrangement of the outlet dosing valves may be different. In addition, the central control computer may be accompanied by further operating computers for quasi-manual intervention in the operation of the plant.
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An automated perfume processing plant for dosing and mixing different substances for the production of perfumes, includes a plurality of reservoirs for different substances, a plurality of outlet dosing valves controlled by a control computer individually arranged on each reservoir, respectively, above a line of mixing vessels on a conveyor belt, whereby the computer is programmed for responding to a perfume code signal from a scanner scanning codes imprinted on each moving vessel, for operating the conveyor belt and dosing valves to deposit a given amount of selected ones of the substances in the mixing vessels for obtaining a desired perfume formulation in each vessel.
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BACKGROUND OF THE INVENTION
The present invention relates generally to the interconnections of roof panels and the securement of the roof panels to a supporting structure.
More particularly, the invention relates to a clip assembly which will provide superior pull-up strength and permit the roof panels to contract or expand due to changes in temperature without damaging the interconnection joint in such a manner as to create leakage problems.
The corrugated type of roof construction considered to be secured by the clip assembly of this invention typically has previously been clamped to a purlin member by direct application of a threaded fastener through the valley of a corrugation and into the purlin. This produces an obvious problem in that the joint must now be secured from moisture by a sealing cap or through the use of a sealing washer. The joint also will not permit relative expansion and contraction of the panels without damaging the panel in the area of the joint.
Other prior art devices relative to a roof hold down fastener utilize a hold down clip device which is interleaved between abutting and crimped lips on adjacent roof panels. The clip is then secured directly to a purlin by rigidly clamping a base portion of the clip thereto and then crimping the abutting edges of the roof panels to an upstanding web formed integrally on the clip. This type of construction has likewise been deficient in its capability to harmlessly allow expansion and contraction of the roof panels.
Other problems that are inherent in the prior art methods and devices for securing roof panels to a supporting structure include their failure to prevent condensation from forming on the clip or the fastener. Even if the joint is properly sealed, the difference in temperature between the outer surface of the building and the inner surface of the building will create condensation and moisture on the clip and fastener located within the building.
SUMMARY OF THE INVENTION
The present invention is directed to solving the problems of the prior art enumerated above. The clip assembly in accordance with this invention will include two discrete members, i.e., a clip member, upon which abutting edges of roof deck panels are crimped and otherwise secured, and a foot member which is directly and fixedly secured to a purlin with a conventional fastener, preferably of a self-drilling variety. The clip and foot members are movably attached to one another through the use of a longitudinal slot of a given length in the clip and a hook portion of the foot which is received in the slot and is of a given width substantially less than the length of the slot. Detachable means for initially locating and retaining the two members in a centered position are provided on associated surfaces of the clip and foot members. The structure of these centering are designed to release upon a certain longitudinal force exerted on the clip member which may typically be that resulting from thermal expansion or contraction of the roof panels.
The clip assembly of the present invention is designed to reduce the possibility of condensation forming within a building as a result of a temperature differential inside and outside of the building. in one embodiment, the foot member is constructed of a thermoplastic material which serves as a thermal barrier between the outermost surfaces of the roof deck and the innermost surfaces of the clip assembly within the building. A significant reduction in the surface area of the clip member in the region of its association with the foot member also serves to reduce the amount of condensation that could be formed within the building.
The two piece clip assembly described herein is economically advantageous, in that a single foot member design can be used to accommodate a wide variety of clip members which may be required to associate with many different roof panel abutting edge configurations. In addition to this economic advantage, the foot member can be preassembled to a threaded fastener member as a washer might be associated thereto using conventional preassembly techniques.
It is therefore a principal object of the invention to provide a roof deck panel joint construction which permits longitudinal expansion and contraction of roof panels without damaging the joint.
it is a further object of the invention to provide a two piece clip assembly which is designed to secure abutting panel edges to a purlin in a concealed manner.
A further object of the invention is to provide a clip assembly which reduces the condensation forming beneath a panel joint construction which is a result of temperature differential inside and outside of the buildings.
Still a further object of the invention is to provide a roof deck clip assembly which is designed to afford maximum strength against uplift forces on the roof deck while utilizing a minimum amount of material in the clip.
These and other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings included herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a preferred embodiment of the clip assembly.
FIG. 2 is a transverse cross-sectional view of the clip assembly connecting a pair of interlocked roof panels to a purlin.
FIG. 3 is a front elevation view of the foot member of the assembly shown in FIG. 1.
FIG. 4 is a side elevation view of the foot member shown in FIG. 1.
FIG. 5 is a rear elevation view of the foot member shown in FIG. 1.
FIG. 6 is a top plan view of the foot member shown in FIG. 1.
FIG. 7 is an exploded view of an alternate embodiment of the clip assembly of this invention.
FIG. 8 is a transverse cross-sectional view of a pair of interlocked roof panels joined to a purlin through the use of the alternate embodiment of the clip assembly.
FIG. 9 is a rear elevation view of the clip member of the alternate embodiment.
FIG. 10 is a side elevation view of the clip member of the alternate embodiment.
FIG. 11 is a rear elevation view of the foot member of the alternate embodiment.
FIG. 12 is a side elevation view of the foot member of the alternate embodiment.
FIG. 13 is a front elevation view of the foot member of the alternate embodiment.
FIG. 14 is a top plan view of the foot member of the alternate embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIGS. 1 and 2, the preferred embodiment of the clip assembly 10 is shown to include a clip member 12 and a foot member 30 which are slidably interconnected by an elongate slot 18, formed in the web 14 of the clip member, and downturned hook section 36, extending from an upper edge of a leg section 34 on the foot member.
The uppermost margin of the clip member 12 will include a flange 16 extending laterally in one direction from the web and configured to correspond with the lips on abutting edges of roof panels to be secured.
The elongated aperture or slot 18 formed in the web of the clip will be of a predetermined length and will form a pair of narrow surfaces 19 and 21 adjacent the side margins of the web providing an advantageous function to be described later herein. The hook portion 36 will be of a width less than the length of the slot 18 to permit relative movement therein.
One of the features of the invention is the strength provided to the joint structure resisting uplift forces which are commonly applied to roof construction of this type. The upstanding leg portion 34 and base surface 32 of the foot are interconnected by a rib structure 42 which strengthens the clip assembly while minimizing the thickness of the material.
The foot member 30 is preferably formed of a thermoplastic material. The presence of this thermoplastic foot member between the clip member and the purlin and/or fastener member 58 provides a thermal barrier which effectively prevents the formation of condensation beneath the roof which normally would occur responsive to a large temperature differential between the outer and inner surfaces of the roof deck. in addition to this insulating feature of the preferred embodiment, the narrow surfaces of web section 19 and 21 reduce the heat transfer surface area from the roof deck panels to the innermost temperature regions. Thus, a further reduction in the possibilities of condensation is inherently provided in the structure of this clip assembly.
It is highly advisable to secure the foot member 30 to the clip member 12 in a manner which will permit movement in either longitudinal direction. For this purpose, a releasable centering and locating structure is formed on mating surfaces of the clip and foot. An aperture 20 is formed through the web of the clip 12 cooperating with and receiving a protuberance 46 formed on the innermost surface of the hook 36. This protuberance 46 snaps in place within the aperture 20 but may be forced out of place as a result of thermal expansion forces applied in a longitudinal direction to the clip 12.
To facilitate assembly of the foot member to the purlin, the fastener 58 and foot member 30 may be preassembled in a manner which is known in the prior art. The foot member may be precisely and accurately located on the purlin through the use of the abutting edge 51 of a roof panel 50 which has previously been secured at its opposite lateral edge. When the foot member has been located, the fastener clamps against reinforcing bosses 44 and fixedly secures the foot to the purlin. The clip 12 is associated with the foot by placing the hook 36 of the foot in the elongated aperture 18 and snapping the protuberance 46 in the associated aperture 20. The clip will also be located and secured in a downward direction through the use of stop ledges 40 which are formed on the foot and which extend laterally outwardly of the leg 34 on the same side of the leg as the hook. The stop ledges 40 abut with the lowermost edge 22 of the clip to prevent further downward movement of the clip and the abutting edges of the roof panels. A typical roof construction will also include a layer of insulative material such as 54 shown in FIG. 2.
When the clip device 12 has been associated with the foot member, the edge 53 of next adjoining panel 52 is crimped to both the flange 16 of the clip and to the associated flange of abutting edge 51. Thus, adjoining panels are secured relative to each other and to the clip 14 but are free to move longitudinally relative to the purlin as a result of interrelation of slot 18 and hook 36.
FIGS. 7-14 illustrate an alternate embodiment of the invention and like reference numerals throughout the various views are intended to designate similar elements or components to that of the first described embodiment.
Clip assembly 10a will again include a clip member 12a and a foot member 30a. Both the foot member 30a and the clip member 12a will be constructed of a sheet metal material. A longitudinal slot or elongated aperture 18a is formed in the web 14a of the clip and is of a predetermined length which is greater than the width of the hook 36a formed in the foot member. The elongate aperture 18a will present narrow surfaces 19a and 21a to reduce the heat transfer in the clip and therefore reduce the condensation formed inside the building. This embodiment will also include rib structure 24a and 42a on the clip and foot respectively, which maximizes the strength of the joint relative to both uplift forces and lateral forces while minimizing the thickness of the material utilized in the clip assembly.
Further reinforcement to the clip is obtained through the use of a downwardly extending flap 26a which is formed from the lowermost edge of the aperture and overlies the lower section of the web 14a.
Spring tabs 40a are punched from the leg 34a of this embodiment and serve to resiliently stop and abut against the bottommost edge 22a of the clip. This interaction prevents unrestrained downward movement of the clip to accurately locate the flange 16a relative to the height of the edges 51a and 53a which are to be secured. It further restricts the downward movement of the abutted joint due to forces exerted on the joint in that area.
The foot member 40a is clamped to the purlin 56a with a pair of fastener members 58a extending through a pair of apertures 38a in the base 32a. As in the preferred embodiment, the foot member 40a may be preassembled to the fastener.
A pair of dimples 46a formed outwardly of the leg mate with a pair of apertures 20a in the lowermost region of the web of the clip. These protuberances and holes releasably lock the member 12a to the member 30a but may be unlocked due to excessive longitudinal expansion forces exerted on the clip 12a.
It should be clear from the above description that a joint construction and clip assembly for use in joint constructions has been provided which secures, in a concealed fashion, adjoining roof deck panels and yet allows the roof deck panels to expand and contract due to thermal changes as well as minimizing the condensation effects of a thermal differential between the outer and inner surfaces of the structure. The clip assembly just described, being of a two piece construction, will provide a greater flexibility in designs of flanges to be used in crimping abutting edges of roof panels without changing the design of the foot member.
While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the appended claims.
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A clip assembly for securing abutting edges of roof deck panels together and to an underlying support structure in such a manner as to conceal the clip assembly and permit relative longitudinal movement of the panels to the support structure responsive to forces from thermal expansion or contraction. The clip assembly comprises a clip member and a foot member slidably interconnected by a hook on the foot member which is received in an elongate slot formed in the clip member. The clip and the foot interconnection includes means to center the two members relative to one another.
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FIELD OF THE PRESENT INVENTION
The present invention relates to construction materials, and more specifically, to pre-fabricated construction materials designed to create durable, economical, eco-friendly buildings rapidly with a minimal labor force and without the use of costly equipment.
BACKGROUND OF THE PRESENT INVENTION
In the quest to create more efficient, cost effective buildings, humans have endeavored to improve the materials used to construct modern buildings, as well as the system by which those materials are employed. Factors such as insulation and roofing can be critical to the cost efficiency of a building. As humans have progressed over time, adobe-based huts evolved into wood and concrete constructs, designed to be durable—to withstand the elements and stand up to the test of time. However, many modern buildings were constructed hastily, and are constructed with bricks, cinderblocks, or other heavy, cumbersome material. Employing such a dense material is more durable than wood or clay, but is time consuming and laborious to construct. Additionally, cinderblock or brick construction materials require strict coordination with plumbers and electricians to construct the building in a timely fashion. With each contractor having a different schedule, this can sometimes be difficult.
As a result of the stone building materials immense weight, costs are high to transport them to the construction site, as well as to build the blocks themselves. In turn, constructing buildings out of bricks, cinderblocks, or other concrete-like material around a predominantly wooden frame is not very cost effective. Other materials, such as polyurethane, acrylic polymers, plastics, and other similar materials are more economical and offer better insulation than traditional building materials. Unfortunately, there is currently no effective way of constructing a building solely with such alternative building materials that offers the same level of structural integrity as brick or cinderblock based buildings provide.
Thus, there exists a need for a new form of building material that provides superior insulation while remaining unitary, light-weight, economical, and eco-friendly, while being predominantly pre-fabricated prior to arriving at the construction site, saving both time and money.
U.S. Pub. No. 2011/0061335 for “Masonry Construction Using Single-Component Polyurethane Foam” by Sheckler, published on Mar. 17, 2011, shows a method of using polyurethane as a bonding agent for concrete blocks or other masonry units. Unlike the present invention, Sheckler does not mention use of polyurethane as a bonding agent for drywall or non-stone materials.
U.S. Pat. No. 3,782,063 for “Expandable Prefabricated Building System and Method of Construction” by Batorewicz et al., issued on Jan. 1, 1974, shows methods of construction for housing systems that are partially prefabricated and assembled prior to shipment to the erection site. Batorewicz et al. employs polyurethane as a “hardenable plastic” applied to portions of the structure, but no mention is made of it being used to together interlocking wall units.
U.S. Pat. No. 5,758,461 for “Lightweight, Prefabricated Building Structures” by McManus, issued on Jun. 2, 1998, shows panels for a prefabricated building that have “friction lock means for interlocking one to another.” FIG. 16F shows one of these friction lock means, namely a tenon and mortise link, that appears similar to the locking means of the present invention, although no mention is made of bonding the link with polyurethane.
U.S. Pat. No. 3,397,496 for “Locking Means for Roof and Wall Panel Construction” by Sohns, issued on Aug. 20, 1968, shows wall, roof and floor modular panel units made of a plastic foam core sandwiched between resin reinforced glass fiber skins.” FIG. 5 shows a side edge interlocking structure that bears some similarity to the interlocking structure used in the present invention, although the pieces are not bonded together with polyurethane.
U.S. Pat. No. 5,349,796 for “Building Panel and Method” by Meyerson, issued on Sep. 27, 1994, shows interlocking panels with a polystyrene, or equivalent material, core. The panels join at their lateral edges with an interlocking joint or snap lock assembly, so that nails or other joining elements are not needed. The interlocking panels in Meyerson connect in a manner dissimilar to the present invention.
SUMMARY OF THE PRESENT INVENTION
The present invention is a mass production building component designed for the construction and assembly of commercial, industrial, and residential buildings based on the injection of polyurethane foam between two preferably metallic panels, constituting a system of walls when interlocked together. The panels are designed to interlock with other similar panels via a unique interlocking clasp found at the ends of each panel. A metallic support column is then placed in the cavity found to exist in the juncture between any two panels, which is secured to the panels via the interlocking clasp. The support column is preferably anchored to the foundation of the building via an anchor plate embedded within the concrete. Windows and doors may be embedded within the panels when the panels are initially created, such that the polyurethane foam holds the window in place. Additionally, electrical outlets, fuse boxes, lighting assemblies, and switches, along with all accompanying wiring are preferably incorporated into the panels at their inception as well. This is preferably accomplished via a wiring cavity, often created by a PVC pipe or other cylinder being left between the two panels at the time when polyurethane is injected between them. This cavity, left behind by the PVC pipe, or the cavity within the pipe itself, is then used to house the wires required for electrical outlets and lighting fixtures which are preferably integrated into the panels as they are made as well.
Given that the electrical systems, vents, doors, and windows are pre-built into the very walls of the house, considerable time may be saved at the construction site of the building. For example, time is not wasted waiting for the electrician to arrive on-site to set up the electrical systems in the walls prior to the construction team being able to proceed, as the electric is already built into the walls, so no electrician is needed to integrate the wiring on-site. Wires routing electricity to the panels are preferably maintained in a trough which is incorporated into the crown beam. The crown beam rests atop the panels, helping to bind them together under the roof.
Roofing is easily placed atop the crown beam of the present invention, and is secured to the crown beam with a conventional mounting mechanism, as well as by joining the metal columns to the roofing material. The mounting mechanism employed for the roof is similar to the mounting mechanism employed to attach the support columns to the anchor plates held within the structure's foundation. The present invention is envisioned to be compatible with a wide variety of roofing materials, ranging from tiles, shingles, sheet metal, etc. It is envisioned that the present invention will enable a group of people to build a structure without the use of any advanced tools, welding, cranes, or heavy machinery.
It is the intent of the present invention to provide easy-to-assemble, durable, eco-friendly, efficient buildings that may be constructed in a single day with a skilled team of 8 to 10 individuals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an illustration of the interlocking edges of the present invention as viewed from above.
FIG. 2 shows an illustration of the present invention being employed to support a third, perpendicular panel.
FIG. 3 displays the present invention from the side, highlighting the embedded window and integrated electrical features.
FIG. 4 exhibits a flow chart detailing the use of the present invention as a construction material.
FIG. 5 illustrates the way in which the roof, support columns, and mounting mechanisms interact with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is a pre-fabricated wall panel designed for the construction of buildings. It has two parallel, preferably metallic sheets, shown as sheets ( 180 ) bound together with a polyurethane layer ( 10 ), preferably foam, injected between the sheets ( 180 ), making the present invention a panel ( 100 ) that is unitary, designed to construct the wall ( 65 ) of a building. The present invention employs a support column ( 30 ), preferably composed of metal, which serves to anchor the present invention to the foundation of a building via a mounting mechanism ( 160 ), as well as to provide a common anchor point for panels ( 100 ). Each panel ( 100 ) has a first end ( 20 ) and a second end ( 50 ), which are preferably shaped as hook-shaped extensions. The hook-shaped extensions on either side of the panel ( 100 ) are such that they are mirrored opposites of each other, as seen in FIG. 1 , which shows the junction of two panels ( 100 ), forming a wall ( 65 ) for a building. This feature is critical to the support system of the present invention, as a first panel ( 60 ) and a second panel ( 70 ), of the present invention to be easily interlocked together in a series, forming a wall ( 65 ) as seen in FIG. 1 , thus constituting the interior and exterior walls of a building. The panels ( 100 ) are designed to be interlocked together without the use of any rivets, screws, welding, or heavy duty equipment. By the nature of the manner by which the panels ( 100 ) interlock together via the hook-shaped extensions, aided by the support column ( 30 ), the junction of the panels cannot be observed from outside of the structure, as the junction appears to be seamless.
The walls ( 65 ) of the building have been created to sustain both hot and cold weather while maintaining an ideal temperature indoors. This is due in part to a polyurethane layer ( 10 ) found as the core of the present invention, which provides optimal insulation while simultaneously providing structural integrity to a building constructed with the present invention. While other foam materials could be employed, polyurethane foam is preferred for a variety of reasons; namely, it is a lightweight, strong insulator that is sticky and fast expanding, assisting its adherence to the panels ( 100 ) of the present invention, as well as other exposed components. Additionally, termites do not eat polyurethane, and other insects cannot such a polyurethane layer ( 10 ) penetrate it, helping to keep insects out of the building.
The preferred embodiment of the present invention is preferably mounted to the foundation of the building via the support columns ( 30 ), and more specifically, via the mounting mechanism ( 160 ) found at the bottom of the support columns ( 30 ), as seen in FIG. 2 . As illustrated, the support columns ( 30 ) are designed to be inserted into an anchor plate ( 110 ), preferably made of steel, which is embedded within the concrete foundation of the building. The mounting mechanism ( 160 ) may consist of a traditional expansion clasp, similar to those found on conventional umbrellas, only larger and made with more durable materials. It is envisioned that, regardless the conventional clasp used as a mounting mechanism ( 160 ), the clasp is preferably permanent, such that the destruction of the foundation of the building would be required in order to dismount the support columns ( 30 ) from the anchor plate ( 10 ).
It is envisioned that there are approximately five differing, generic types of the present invention that are created to be used to construct buildings. Each type is simply a differing form of the same concept—namely a polyurethane injected panel which employ a specific form of edge that is able to interlock with the edges of other panels, all of which are anchored to the foundation for stability. Types may include a window wall panel, an electrical wall panel, a door panel, vent panels, and standard blank panels. Additionally, the underlying roof panels are preferably constructed similarly to the panels ( 100 ) of the present invention.
A crown beam ( 120 ) is placed atop the panels, additionally binding them together and increasing the structural integrity of the building. The crown beam is preferably composed of a single sheet of bent metal, shaped into a trough ( 130 ) approximately the same width of the panels ( 100 ). The crown beam ( 120 ), in addition to the support columns ( 30 ) and anchor plates ( 110 ) provide the strength of the structure. By employing such simplistic forms, a structure constructed with the present invention does not require any type of welding, special tools, or heavy duty equipment to successfully build a structure. It is preferably envisioned that a structure built with the present invention need not require much more than a conventional screwdriver to assemble.
The panels ( 100 ) are preferably designed according to the structural requirements in place at the location they are intended to be used. Therefore, wind speed, flood potentials, and seismic conditions are taken into consideration in order to determine the optimal dimensions of the panels ( 100 ), as well as the depth at which the anchor plates ( 110 ) should be placed in the concrete foundation. For locations prone to earthquakes, the anchor plates ( 110 ) are thicker, and other forms of mounting mechanisms ( 160 ) may be employed to secure the support columns ( 30 ) to the anchor plates ( 110 ). For example, the anchor plate itself may be of a thicker, more durable metal for installations in locales prone to frequent seismic activity. Additionally, the support columns ( 30 ) could be made of a more shatter resistant alloy to conform to the construction parameters of the structure.
The crown beam ( 120 ) of the present invention is preferably placed on the frame of the structure, which is established by the interlocking panels ( 100 ), as seen in FIG. 5 . The crown beam ( 120 ) serves as a buffer between the roof ( 140 ) and the top of the panels ( 100 ). This buffer, shown as a trough ( 130 ), provides a space for electrical wires and plumbing to be routed to the appropriate rooms easily before the roof ( 140 ) is mounted to the structure. The roof ( 140 ) is constructed of similar panels that are injected with the polyurethane ( 10 ) foam; however, the sheets employed to make the roof panels ( 150 ) are not parallel. One sheet of the roof panel ( 150 ) is slanted to allow for the slope of the roof ( 140 ), providing an avenue for water runoff. Due to the nature of the construction of a structure in this fashion, the structures do not have attics or large vacant cavities within the roof ( 140 ). This helps to ensure optimal insulation from the elements, as well as to eliminate potential habitats for insects.
The roof panels ( 150 ) of the present invention are preferably built of a first roof sheet ( 180 ) and a second roof sheet, preferably oriented at an angle to each other, ideally similar in composition and structure to the panels employed to construct the frame ( 170 ) of the present invention. The roof panels ( 150 ) are preferably built of sheets ( 180 ), preferably arranged at an angle, bound together with an injected polyurethane layer ( 10 ), extending across the frame all in one solitary piece. This solidary helps ensure moisture does not enter the structure in the form of humidity. The mounting mechanism ( 160 ), as well as the reinforcements of the roof panels ( 150 ) are pre-installed and attached at the factory prior to the injection of the polyurethane layer ( 10 ) between the sheets ( 180 ). The anchoring of the roof panel to the beam is accomplished via mounting mechanism ( 160 ) similar to the one used for anchoring the support columns ( 30 ) to the anchor plate ( 110 ).
The mounting mechanism ( 160 ) which anchors the roof panels ( 150 ) to the crown beam ( 120 ) cannot preferably be seen from the interior or exterior of the structure. This helps to ensure that the structures constructed employing the present invention remain aesthetically pleasing, and do not display unsightly hinges, rivets, or welding junctures. The mounting mechanism ( 160 ) and reinforcements of the roof panels ( 150 ) are preferably pre-installed and attached at the factory prior to the injection of the polyurethane layer.
The preferred embodiment of the present invention is best seen as it is used within the larger system of a structure's construction, as seen in FIG. 4 . In summary, anchor plates are embedded within the concrete foundation ( 200 ) of a structure. Polyurethane is injected between two identical, parallel sheets ( 210 ). Upon drying, the parallel sheets are bonded together in a solitary panel ( 220 ). The edges of the panel are preferably bent into mirrored, semi-enclosed hooks ( 230 ). The hooks of the panels interlock with the hooks of other panels during assembly of a structure at the construction site ( 240 ). Support columns are dropped down into the semi-enclosed hooks, binding the panels together and giving the structure strength ( 250 ). The anchor plates are configured to interlock with the support columns, ensuring the panels remain upright.
A conventional mounting mechanism ( 160 ) is used to mount the support columns to the anchor plates ( 260 ). The panels are interlocked together until the frame of the structure is enclosed and complete ( 270 ). A crown beam is placed atop the completed frame, helping to bind the panels together and to give the structure strength ( 280 ). Electrical wires and plumbing are routed along the crown beam, in the gap that exists between the top of the panels and the roof ( 290 ). A roof is placed atop the crown beam and is mounted to the crown beam via a mounting mechanism ( 300 ). The roof ( 140 ) is composed of roofing panels, constructed in a similar fashion to that of the panels making up the walls of the present invention.
The design of the roof panels ( 150 ) are such that they are built using specially designed molds, wherein the sheets ( 180 ) are held at an angle when unified with an injection of polyurethane ( 10 ) foam. The lower sheet ( 180 ) of the roofing panel ( 150 ) inherently acts as the ceiling of the structure. This design is a critical portion of the building system, which aids in the rapid and easy assembly of the structure at the construction site by eliminating the need to create any additional ceilings, reducing erection time and overall construction costs.
The design of the structure created with the present invention ensures that there are no empty spaces within the roof portion of the structure, such as an attic. The lack of an attic helps to avoid the need for additional insulation, and assists in prevention against the invasion of insects, humidity and mold.
In alternate embodiments of the present invention, it is envisioned that other materials may be used as the sheets ( 180 ) used to create the panels ( 100 ). For example, granite or wood sheets could be fabricated to be strong enough to withstand the pressure established during the polyurethane layer injection process. These panels ( 100 ) could similarly be used to form the frame ( 170 ) and walls of a structure.
Similarly, alternate embodiments of the present invention may prefer to employ alternate conventional mounting mechanisms in their approach to the mounting and securing of the support columns ( 30 ) to the anchor plates ( 110 ) and to the roof ( 140 ) of a structure constructed with the present invention.
It is to be understood that the present invention is not limited to the embodiments as described above. There may be variations in the present invention that are not limited to the detailed description of the embodiments, but still maintain the essence of the invention as described in the specification.
To reiterate, the present invention is an interlocking building system that has a first sheet, which has a first end and a second end. A first hook-shaped extension is preferably located at the first end of the first sheet. A second sheet also has a first end and a second end. The first end of the second sheet also has a hook-shaped extension. The first sheet and the second sheet are preferably in parallel planes. A polyurethane layer ( 10 ) is injected between said first sheet and said second sheet, binding them together, and forming a first panel. The present invention also has at least one support column, at least one mounting mechanism, and at least one anchor plate. A second panel is created that is identical to the first panel. The first hook shaped extension of the first panel is interlocked to a second hook-shaped extension of the second panel. A support column ( 30 ) is disposed between the first hook-shaped extension of the first panel and the second hook-shaped extension of the second panel. The support column ( 30 ) of the present invention is inserted within the anchor plate ( 110 ), providing stability. The support column ( 30 ) is then secured to the anchor plate ( 110 ) via a mounting mechanism ( 160 ).
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An apparatus constituting the walls and frame of a building with a series of interlocking panels, preferably composed of two sheets of metal, bound together by polyurethane foam injected between them. The panels are secured to the floor via metallic columns found at each juncture between two panels. Electric assemblies and setups, as well as plumbing outlets are preinstalled within the panels, facilitating rapid installation. Windows, doors, and A/C vents are also crafted into the panels at their inception, prior to their transport to the construction site. It is the intent of the present invention to provide an avenue for affordable, durable, and efficient housing that may be constructed quickly with minimal effort in the absence of heavy machinery, and without any advanced tools.
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BACKGROUND OF THE INVENTION
Heretofore, oil and/or gas fields have been developed onshore by drilling a plurality of essentially vertical, spaced apart wellbores in checkerboard fashion. In the offshore environment, a plurality of curved wellbores have been drilled from a single platform, each curved wellbore extending outwardly in a different direction away from the platform.
BRIEF SUMMARY OF THE INVENTION
In accordance with this invention, there is employed a method for drilling a plurality of wellbores to develop an oil and/or gas field which uses curved wellbores but which uses such wellbores in a manner significantly different from that of the prior art. In this invention, at least one pair of elongate drilling zones which are essentially parallel to and spaced from one another are employed across a substantial portion of the oil and/or gas field to be developed. Alternate curved wellbores are drilled along the length of both drilling zones, adjacent wellbores being longitudinally spaced from one another. Each wellbore is deliberately directed toward a predetermined oil and/or gas producing formation and the opposing drilling zone. When the wellbore reaches the predetermined oil and/or gas producing formation, the wellbore is straightened to thereafter follow the formation until the wellbore reaches the vicinity of the opposing drilling zone. A plurality of such alternate longitudinally spaced curved wellbores are drilled along any given pair of drilling zones and a plurality of pairs of drilling zones can be employed to develop fields of larger areas.
Accordingly, it is an object of this invention to provide a new and improved method for developmental drilling of an oil and/or gas field. It is another object to provide a new and improved method for maximum developmental drilling of a producing field with the least number of wellbores. It is another object to provide a new and improved method for developmental drilling for carrying out enhanced oil recovery processes.
Other aspects, objects and advantages of this invention will be apparent to those skilled in the art from this disclosure and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross section of the earth with a wellbore extending downwardly from the surface and then curving towards and into a producing formation after which the wellbore is straightened to follow the formation.
FIG. 2 shows a plan view of the development of a field in accordance with this invention using a plurality of spaced apart drilling zones and a plurality of curved wellbores drilled along and away from each drilling zone.
FIG. 3 shows a plan view of the various straightened portions of the curved wellbores of FIG. 2 and how these wells can be employed in an enhanced oil producing process.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the earth's surface 1 with a drilling rig 2 mounted thereon. A wellbore 3 is drilled from rig 2. Wellbore 3 starts initially as a conventional essentially vertical wellbore which is denotated in FIG. 1 by the portion V. At kick-off point 4, wellbore 3 is curved from vertical in a conventional manner. A radius of curvature R is employed which is designed, based upon the depth of producing formation 5, to reach a point 6 in the interior of formation 5 at which point 6 the curving wellbore 3 is straightened so that an essentially straight portion H of wellbore 3 can be drilled following along formation 5.
FIG. 2 shows the irregular outline 10 of an oil and/or gas field. Across a substantial portion of field 10 are laid out elongate drilling zones 11, 12 and 13 on the surface of the earth 1. Drilling zones 11 through 13 can be a continuous roadway or merely an imaginery zone along which wells are to be drilled at various drill sites.
Drilling zones 11 and 12 form a pair of spaced apart longitudinally extending drilling zones which are essentially parallel to one another, although true parallelism is not required. If the first drilling site on first drilling zone 11 is denotated by drilling rig 2, then it can be seen that wellbore 3 curves from kick-off point 4 towards producing formation 5 and, at the same time, towards opposing, second drilling zone 12. Note that the curved portion R of wellbore 3 extends across a substantial part of the space between opposing adjacent drilling zones 11 and 12 and that the remainder of such space is covered by essentially straight wellbore portion H.
Wellbore portion H is shown in FIG. 1 to be essentially horizontal, although this may not necessarily be the case in actual practice if formation 5 is tilted upwardly or downwardly from point 6. However, for sake of simplicity, portion H will be described as the horizontal portion of the wellbore although it is to be understood that this portion does not need to be truly horizontal anymore than vertical portion V need be truly vertical.
Horizontal portion H extends toward opposing drilling zone 12 and is terminated somewhere in the vicinity of drilling zone 12. That is to say, end 7 of wellbore 3 is somewhere near or under drilling zone 12 although it should not extend until it interferes with curved wellbore 14 which extends from drilling rig 15 towards opposing drilling zone 13. Although wellbore 3 is shown to be drawn essentially perpendicular to drilling zones 11 and 12, this is not a requirement for this invention. Wellbore 3 could be drilled at an angle to drilling zones 11 and 12 if desired or necessary and the benefits of this invention still achieved. For example, this might be done in some fields to more precisely fit the direction of the minimum horizontal stress and hydraulic fracture planes of the producing formation in question. This modification would increase the length of the drilling zones and the surface distance between wellheads and decrease the perpendicular distance between drilling zones but would not change the number of wells required for a given subsurface spacing of horizontal well paths.
In accordance with this invention, after drilling first curved wellbore 3 from first drilling zone 11, a first curved wellbore 16 is drilled from second drilling zone 12 by use of drilling rig 17. Curved wellbore 16 curves toward formation 5 and, at the same time, toward opposing drilling zone 11 so that the resulting curved wellbore 16 looks like wellbore 3 of FIG. 1 but curves in the opposite direction. End 18 of the horizontal portion H of curved wellbore 16 terminates in the vicinity of drilling zone 11.
Wellbore 16 is deliberately drilled so that it is longitudinally spaced a distance L from wellbore 3 along the length of drilling zones 11 and 12.
Thereafter, drilling rig 19 which can be the same or different rig as those used for 2 or 17, is employed to drill from drilling zone 11 a third longitudinally displaced curved wellbore 20 which extends over to the vicinity of opposing drilling zone 12. This drilling of alternating curved wellbores is repeated along the length of drilling zones 11 and 12 for a distance deemed necessary for adequate developmental drilling of that portion of field 10.
If field 10 is sufficiently large in area that a single pair of drilling zones 11 and 12 does not adequately develop the field, then additional pairs of drilling zones can be employed such as drilling zones 12 and 13 of FIG. 2 using alternating longitudinally spaced apart curved wellbores 14, 21, and 22 which are drilled in the same manner as wellbores 3, 16 and 20.
The distances R, H, and L can vary widely depending upon the depth of formation 5, the capacity of the drilling rigs being used, the spacing between adjacent opposing drilling zones and a number of other factors. For example, this invention can be employed when a plurality of producing zones are available in which case, a single predetermined producing zone will be used as a target zone, as shown in FIG. 1 for formation 5.
After field 10 has been developed by drilling curved wells in the manner described for FIG. 2, when considering only the horizontal portions of each wellbore, a staggered sequence of horizontal wellbores is achieved as shown in FIG. 3, each horizontal portion being spaced from the other by a longitudinal length L. If a plurality of wellbores near the top side of field 10 in FIG. 3 are employed to inject an oil production enhancing fluid, e.g. a micellar displacement or miscible displacement fluid, into formation 5, a bank of such fluid can be formed in formation 5 to form a line drive 30 in that formation. Then, with additional injection of the oil production enhancing fluid and/or a drive fluid to push the oil production enhancing fluid, a line drive 30 is formed from such fluid(s) and pushed in the direction of arrows 31 so that a greater amount of oil than normal can be produced from production wells which lie ahead of line drive 30, e.g., wells 32 through 35 in FIG. 3. It can be seen from the pattern of overlapping horizontal portions H, that essentially complete coverage of field 10 can be achieved and enhanced oil recovery realized by using the drilling pattern of this invention as disclosed hereinabove with respect to FIG. 2. If an enhanced oil recovery process is anticipated, the original curved wells could be drilled in a direction that essentially parallels the expected plane of the vertical fractures for formation 5. With this arrangement, injection in a well could cause a fracture that would extend vertically upward to the top of formation 5 and laterally along the length of the horizontal hole H. This could tend to more uniformly distribute the injected enhanced oil recovery fluids across the full face of producing formation 5 and could also prevent streaks from causing vertical flow barriers.
Although the radius of curvature R and horizontal distance H can vary widely depending upon the drilling apparatus available, the nature of formation 5 and many other parameters, for sake of example, if the curved portion of the wellbore has a build rate of 21/2° per 100 foot of wellbore drilled, this is equivalent to a radius of curvature R for the wellbore of 2300 feet. If formation 5 is about 3500 feet below the earth's surface 1, wellbore 3 could be drilled vertically to a depth of 1200 feet at point 4 at which time, the wellbore would be kicked off of vertical and start to build at 21/2° per 100 foot towards horizontal.
Thus, wellbore 3 would curve from point 4 to point 6 a lateral distance of 2300 feet away from the vertical projection of wellbore 3. If drilling zones 11 and 12 are spaced 4600 feet apart as indicated by arrow 23 in FIG. 2, center-to-center, and horizontal distance H of wellbore 3 is also 2300 feet, then wellbore 3 will reach essentially to the center of drilling zone 12. The foregoing would also be true for each of wells 16, 20, 14, 21, 22, using the 2300 foot radius of curvature, 2300 foot horizontal segment H for a total of 4600 feet between adjacent opposing drilling zones.
In this situation, it would take 10 wells per 1000 foot of longitudinal length L of drilling zone in order to place the horizontal drainhole segment on 200 foot spacing in formation 5. In an area of 528 acres, 50 wells would be employed if drilled in the manner described in relation to FIG. 2 and this would yield a total wellbore contact length with formation 5 of 115,000 feet. It would require about 2300 vertical wells in a 50 foot thick producing formation 5 to have the same 115,000 foot contact length produced by following the pattern of this invention. Accordingly, by this invention, there is produced an equivalent well spacing from a surface contact point of view of 0.238 acres per well by drilling 50 wells in 528 acres or roughly 1 well for every 101/2 acres of surface area.
The 2300 foot radius of curvature and length of horizontal segment H is not required for this invention. Other curvatures and horizontal lengths can be employed to provide even greater incentives. For example, with a 2640 foot radius of curvature, the horizontal tail and build portion would be lengthened by a little over 500 feet to a measured depth of 7647 feet but would permit placing adjacent opposing drilling zones essentially one mile apart.
It can be seen from the above description of this invention even if the effective cost of the curved wellbores employed by this invention were twice the cost per foot of conventional vertical wellbores, the horizontal wellbores would be less than one-tenth the cost of wells required for the pattern than vertical wellbores so that substantial net savings could be realized from the proper application of this invention even though more expensive wellbores are employed in carrying out the pattern of this invention.
Reasonable variations and modifications are possible within the scope of this disclosure without departing from the spirit and scope of this invention.
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A method for drilling a plurality of wellbores for producing an oil and/or gas field to the maximum extent with the least number of wellbores wherein at least two longitudinally extending drilling zones are established spaced apart and essentially parallel to one another and drilling alternate longitudinally spaced apart curved wellbores from said drilling zones, each curved wellbore extending toward the producing formation and the opposing drilling zone, each curved wellbore being straightened out and thereafter following a predetermined producing formation until the wellbore reaches the vicinity of the opposing drilling zone. A plurality of the alternating longitudinally spaced wellbores are employed along a pair of drilling zones and a plurality of pairs of drilling zones can be employed. The resulting series of wellbores can be employed to carry out an enhanced oil recovery process by using part of said wellbores as injection wells and part of said wellbores as producing wells.
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SPECIFICATION
This application claims priority to U.S. Provisional Application Ser. No. 60/224,330, filed Aug. 11, 2000.
BACKGROUND OF THE INVENTION
The present invention generally relates to office exercise devices which can be used by a user while seated at a desk, and more particularly, exercise devices which may be removably mountable to a chair.
Many people appreciate the need to exercise regularly. Unfortunately, busy business schedules often make it difficult to incorporate a regular exercise schedule into a working week. An exercise device that can be used while a person is working would provide the benefit of exercise which can be achieved during working hours.
Lower body exercise devices known in the art for use in a seated position generally are large, complicated and/or cumbersome and are not easily adaptable for use with any office furniture. For example, U.S. Pat. No. 5,813,947 (the “'947 patent”) discloses an exercise apparatus which can be used while the user is working. The exercise apparatus of the '947 patent is an exercise desk which includes an exercise apparatus mounted to an enclosure which has an upper working surface. It is used in a standing position and is therefore not well suited for the work place.
U.S. Pat. No. 5,807,212 (the “'212 patent”) also discloses an exercise apparatus for use while working. The apparatus of the '212 patent can be used while in a seated position in combination with a chair. It includes an anchor means attached to an exercise means, a barrier bar, a sleeve attached to the exercise means which includes a locking aperture, a stem slidably located within the sleeve and to which the barrier bar is attached and a channel member which has receptacles for receiving the legs of a chair and which connects to the locking means. The apparatus of the '212 patent is rather large. In addition, due to the design of the channel member which has receptacles for receiving the legs of a chair, the exercise apparatus of the '212 patent is not easily adapted for use with any type of desk chair. For example, an office chair with five wheels cannot be used with the exercise device of the '212 patent. Furthermore, due to its size, the exercise apparatus of the '212 patent is not easily stored.
The present invention addresses the inadequacies of the prior art by providing a simplified exercise device for use while seated in a chair. The exercise device of the present invention is small, light weight and easily secured to any chair. In addition, due to its relatively small size and light weight the exercise device of present invention is easily stored.
SUMMARY OF THE INVENTION
The present invention is directed to an exercise device for use while seated in a chair at a desk or other working surface. The device of the present invention can be used with virtually any type of chair. Generally, the device includes a mounting element, an exercise element mounted to the mounting element, and a retractable securing element for removably securing the device to a chair. The exercise element is preferably a pedal element having two pedals, similar to the pedals of a bike, which may be mounted to the mounting element with an attachment element. Alternatively, the exercise element is a stepping element having two steps similar to those used on a stair master. The exercise device may further comprise a height adjustment element and/or a resistance adjustment element operationally linked to the exercise element.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be better understood with reference to the attached drawings in which—
FIG. 1 is a perspective view of a first embodiment of an exercise device in accordance with the present invention;
FIG. 2 is a top view of the exercise device of FIG. 1 ;
FIG. 3 is a perspective view of a second embodiment of an exercise device in accordance with the present invention; and
FIG. 4 is a top view of the exercise device of FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1-4 , the exercise device of the present invention generally includes an exercise element 4 or 11 which is mounted to a mounting element 6 which comprises a retractable securing element 7 . The mounting element 6 is preferably from about 0.5 to 2.0 feet long and from about 1.0 to 3.0 feet wide. More preferably, the mounting element 6 is about 1 foot long and from about 1 to 2 feet wide. The mounting element 6 may be made from any suitable material and preferably is a piece of hard plastic or rubber. The retractable securing element 7 may be any suitable material that can secure the mounting element to any chair to ensure the exercise device of the present invention remains stationary during use. For example, the securing element may be two sturdy but flexible ropes that can be used to tie the device to any chair. Preferably, the securing element comprises two velcro straps 8 placed on either side of the mounting element 6 . More preferably the securing element 7 includes a retractor element 9 into which the velcro straps 8 are retracted and which is affixed to either side of the mounting element 6 .
In addition, the exercise device of the present invention includes a resistance adjustment element 3 which is operationally linked to the exercise element 4 or 11 . Nonlimiting examples of resistance adjustment elements 3 known in the art include pneumatic spring cylinders, pneumatic or hydraulic cylinders or dashpots, an elasotmeric rod or tube, a spring, etc.
A first embodiment of an exercise device 10 that may be used while the user is seated at a desk or other working surface is illustrated in FIGS. 1 and 2 . Referring to FIG. 1 , the exercise element 4 is a pedal element having two pedals 5 similar to bicycle pedals. The exercise device of the first embodiment further comprises an attachment element 1 to which the pedal element is attached and which mounts the pedal element to the mounting element 6 . Any suitable pedal element known in the art may be used in accordance with the present invention. The attachment element 1 may have a non-use position, which will allow the user to lay the attachment element flat for storage purposes, as well as a use position (i.e. an upright position). In a preferred embodiment, the pedal element is about 1 foot high. Referring to FIG. 2 , the pedal element may be raised or lowered for comfort with a height adjustment element 2 . The exercise element 4 is further operationally linked to the resistance adjustment element 3 which may be adjusted by the user to either increase or decrease the force required to pedal.
A second embodiment of an exercise device 13 that may be used while the user is seated at a desk or other working surface is illustrated in FIGS. 3 and 4 . Referring to FIG. 3 , the exercise element of the present invention is a stepping element 11 having two steps 12 similar to a stair master. In a preferred embodiment, the steps 12 are about 1 foot high. The stepping element 11 is attached to the mounting element 6 in any manner suitable to achieve functionality, i.e. so that the user may exert force on the steps in an alternating fashion similar to a stair master. Referring to FIG. 4 , the stepping element 11 may be operationally linked to a resistance adjustment 3 . More than one resistance adjustment may be used in accordance with the present invention. For example, each step of the stepping element may be operationally linked to a separate resistance adjustment element such that the user may adjust the force required for only one leg.
The height of the exercise device of the present invention should be low enough so that the device will fit under a desk. In addition, the height of the exercise element should be low enough that the user's knees will not hit the top of the desk while the user is exercising.
Other modifications of the exercise device of the present invention are also contemplated. For example, the exercise element may be similar to a leg press and may be used in place of the pedal element and stepping element. The device may be made from any suitable materials include, but not limited to, plastics, rubbers, metals, woods, etc. The device may include straps for strapping the exercise element to the foot of the user in order to ensure that the user's foot does not slip off the exercise device while exercising. In addition, the exercise element may be itself removable and/or movable to make room for the user's legs under the desk when the device is not in use.
Although the present invention has been described in connection with the preferred form of practicing it, those of ordinary skill in the art will understand that many modifications can be made thereto within the scope of the claims that follow. Accordingly, it is not intended that the scope of the invention in any way be limited by the above description.
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The present invention relates to an exercise device generally comprising a mounting element, an exercise element mounted to the mounting element, and a retractable securing element for removably securing the device to a chair. The exercise device of the present invention may be used by a user while seated in a chair and is relatively small, light weight and easily stored.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a self-propelled forage harvester with a positionable operator's cabin.
[0002] A self-propelled vehicle with a positionable operator's cabin are disclosed for example in the German patent document DE OS 2 046 552. In the inventive embodiment of this vehicle the operator's cabin is arranged rotatably on an arm and is horizontally turnable around a pivot axis, and can be adjusted in at least two positions. The frames of the vehicle are equipped with devices for coupling and for receiving of a working elements. Before the receiving of working element, the operator's cabin is turned from the required mounting space for the working element into a position, in which the operator's cabin is oriented toward the frame and provides an optimal visibility of the operator in traveling direction or on the working element. The disadvantage of such an embodiment is that the operator's cabin is not positioned-changeable around the coupled working element to an opposite position.
[0003] Modern forage harvesters travel on the streets with a speed of up to 40 km/h. With the coupled tool, the load on the front axle when compared with the load on the rear axle is very high, the center of gravity of the forage harvester is located very close to the front axle, and due to the arrangement of the drive is placed very far from the ground. With this weight distribution the vehicle during acceleration or braking has an easy inclination to vibrations or swinging. The vehicles which sensitively react to steering impacts and roadway unevenness are difficult to control at high speeds. The non-uniform load distribution is compensated by a ballast which is mounted on the supporting frame in the region of the rear axle. However, this has the disadvantage that the total weight of the forage harvester is increased and simultaneously the usable load is reduced.
SUMMARY OF THE INVENTION
[0004] Accordingly, it is an object of the present invention to provide a forage harvester in which the traveling properties and thereby the traveling comfort of the machine are adapted to different operational situations on the street and on the field with and without a coupled front attachment, and thereby these properties are improved.
[0005] In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a self-propelled forage harvester, comprising a chassis; an operator's cabin arranged on said chassis; a chopper drum; an ascending lower discharge chute extending from said chopper drum inside said chassis to a level above said chassis; and a working element arrangement, said operator's cabin being movable from a street operating position into at least one chopper operating position and vice versa, and said cabin embracing said at least one working element arrangement during changes between said positions.
[0006] When the operator's cabin is movable from at least one street operational position to at least one chopper operating position and vice versa and the cabin during the change from the street operating position to the chopper operating position and vice versa encompasses a working element arrangement it, is guaranteed that the forage harvester can operate in two traveling directions and the operator has a free visibility forward in the corresponding traveling direction.
[0007] In accordance with another advantageous embodiment of the present invention, the working element arrangement is a discharge chute.
[0008] In accordance with still another feature of the present invention, the change of the position is performed for example by displacing and/or turning of the cabin. The cabin is therefore connected with the chassis in any position.
[0009] In order to provide a higher flexibility in the position change, the turning device can be designed with a longitudinally-changeable turning arm, so that the cabin can be displaced with respect to the axle units.
[0010] In accordance with a preferable embodiment of the present invention, the turning device has a rotary axis which is arranged outside the lower discharge chute, so that the turning device can be partially turned around the lower discharge chute without contacting the lower discharge chute.
[0011] In accordance with the invention two raising elements are provided on the chassis and located at opposite sides of the chassis. Therefore the operator of the operator's cabin can comfortably and reliably reach the chopping operational position and the street operational position.
[0012] In accordance with a preferable embodiment of the present invention, the discharge chute is vertically turnable about a horizontal axis. Therefore it can be lowered in the street operation and can be displaced upwardly and further turned during the chopper operation of the chopping product for overloading.
[0013] In accordance with a variant of the present invention which has a simple construction and excludes collisions, the operator's cabin and the upper discharge chute can be movable in the same direction to different positions around the lower discharge chute.
[0014] For avoiding the danger of collision between the turnable operator's cabin and the longitudinally-changing upper discharge chute, the movements of the operator's cabin and the upper discharge chute are advantageously coupled with one another.
[0015] In accordance with the present invention, the movement of the upper discharge chute is limited by an abutment. It is therefore guaranteed that on one hand a flexibly designed overloading region can be covered and on the other hand collisions with further components are avoided.
[0016] The operator's cabin in the street operating position is arranged advantageously substantially centrally between the axle units. In this position the vibrations which can act on the operator are reduced.
[0017] In accordance with a further embodiment of the present invention, the operator's cabin is arranged near the lower discharge chute. In this position the operator has the best view of the upper discharge chute.
[0018] Alternatively, the operator's cabin can be mounted displaceably on a displacement guide and simultaneously can be supported turnably about a vertical axis. In this case it is possible that the cabin can move completely around the lower discharge chute.
[0019] In accordance with one embodiment of the displacement guide, the rotary axis of the upper discharge chute and the movement center point of the displacement guide are coaxial. The upper discharge chute and the cabin move advantageously around a common center.
[0020] In the above mentioned variant, preferably a joint arm is articulately connected between the displacement guide and the operator's cabin. This provides for a high flexibility in the position change.
[0021] For uniform distribution of the load of the chopper, the functional component groups and/or the front attachment in the region of the first axle unit are arranged on the chassis and simultaneously the drive unit is arranged in the region of a further axle unit. This arrangement positively influences the traveling comfort, since it provides an advantageous weight distribution on the forest harvester. The center of gravity of the drive unit is located in the vicinity to the further axle unit so that the forage harvester travels tilting-free in an inclined position.
[0022] In accordance with a further embodiment of the present invention, the functional component groups are formed by a drawing-in chute and the lower discharge chute.
[0023] In a further embodiment of this design, the lower discharge chute has a plurality of working elements. The working elements in this embodiment can include a chopper drum, a corn cracker and a post-accelerator.
[0024] In a further embodiment of this variant, the drawing-in chute has a plurality of compression rolls.
[0025] The drive unit of the inventive forage harvester in the present embodiment is composed of a motor, a transmission and a cooler.
[0026] In order to move the center of gravity of the front attachment closer to the supporting frame, the front attachment in a transporting position is turnable at least partially in the region of the position of the cabin in the chopper operative position.
[0027] The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, 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 DRAWINGS
[0028] FIG. 1 is a side view of an inventive forage harvester with a partial section through functional component groups;
[0029] FIG. 2 is a schematic plan view of the inventive forage harvester with turned-out front attachment in a chopper operating position;
[0030] FIG. 3 is a schematic plan view of the inventive forage harvester with a turned-in front attachment in a street operating position; and
[0031] FIG. 4 is a detailed view of a second embodiment of an inventive turning device in a plan view.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] A forage harvester in FIG. 1 is identified as a whole with reference numeral 100 . It has a chassis 10 and an operator's cabin 30 arranged on the chassis. In addition to the cabin 30 , also an upper end of an ascending lower discharge chute 46 is arranged on the chassis 10 . It extends from a chopper drum 43 inside the chassis 10 to a level above the chassis 10 .
[0033] In a street operational position 31 the operator's cabin 30 is located between substantially a first axle unit 12 and the lower discharge chute 46 , and the view of the operator for controlling is oriented in direction of the first axle 12 . The operator's cabin 30 is placed on a turning device 50 which is turnable horizontally about a vertical pivot axis of rotation 51 . The turning device 50 is formed as a longitudinally-displaceable straight turning arm 55 with an outer end, on which the operator's cabin 30 is supported turnably around the vertical turning axis of rotation 53 . The axis of rotation 51 and the turning device 50 are located forwardly of the lower discharge chute, so that during turning of the operator's cabin over 180° around the lower discharge chute 46 , neither the operator's cabin 30 nor the turning device 50 contact the lower discharge chute 46 or exceed a safety distance.
[0034] A rotatable upper discharge chute 48 is flanged on the lower discharge chute 46 rotatably around a vertical axis of rotation 49 with a rotary rim 47 . The upper discharge chute 48 is additionally adjustable in its height around the horizontal axis 58 . The upper discharge chute 48 is adjusted in a street operating position 60 in direction of a further axle unit 11 .
[0035] The chassis 10 of the forage harvester is supported by the two axle units 11 , 12 . The first axle unit 12 is provided with smaller wheels than the further axle unit 11 . In the vicinity of the first axle unit 12 , the chassis carries a drive unit 20 . FIG. 1 shows the drive unit 20 in a partial section. It is composed of a motor 21 , a transmission 22 , and a cooling system 23 . The greater part of the load of the drive unit 20 rests on the first axle unit 12 , while the center of gravity of the drive unit 20 is located, due to the arrangement of the motor 21 and the transmission 22 , substantially at the height of the first axle unit 12 .
[0036] A functional component group 40 is arranged in the region of the second axle unit 11 . It includes a drawing-in chute 41 , in which several compression rolls 42 are rotatably supported, and then an approximately vertically extending lower discharge chute 46 arranged after the drawing-in chute 41 and accommodating a chopper drum 43 , a subsequent not shown corn cracker, and a post-accelerator 45 . In accordance with the present invention, further not shown elements can be also associated with the lower discharge chute 46 .
[0037] A front attachment 200 which is known in the art and not shown in detail is associated with the drawing-in chute 41 . The greater part of the load of the functional component group 40 and the front attachment 200 rests on the second axle unit 11 .
[0038] The front attachment 200 is folded in a transportation position and is arranged partially over the supporting frame 10 .
[0039] FIG. 2 shows a schematic plan view of the inventive forage harvester 100 with a series-independent attachment 200 . The operator's cabin is located in a chopper operating position 32 over the axle unit 11 and the view of the operator during controlling is oriented toward the front attachment 200 . The upper discharge chute 43 is adjusted in a chopper operating position 65 transversely to the longitudinal axis of the forage harvester 100 , from which it is turnable during chopping around the axis of rotation 49 opposite to the clockwise direction over 180°. The turning device 50 and the axis of rotation 51 are arranged near the lower discharge chute 46 .
[0040] During changing of the position of the operator's cabin 30 and the upper discharge chute 48 from the street operating position 31 , 60 to the chopper operating position 32 , 65 and during changing back, the operator's cabin 30 and the upper discharge chute 48 move in the same direction around the lower discharge chute 46 . Abutments prevent collision of the operator's cabin 30 and the upper discharge chute 48 . The movements of the operator's cabin 30 and the upper discharge chute 48 are coupled with one another during the position change. The movements are monitored for example electronically by sensors, and their determined data are transmitted to an evaluation unit. The evaluation unit evaluates the data and supports the movements for the upper discharge chute 48 when the operator's cabin 30 for example by software.
[0041] The operator's cabin 30 can be reached over a raising element 16 in the vicinity of the axle unit 11 , at the right side of the forage harvester 100 .
[0042] The unfolded front attachment 200 which is mounted at the end side on the chassis 10 in front of the drawing-in chute 41 , is located in a working position 210 . The front attachment 200 extends outwardly beyond the width of the forage harvester 100 , and in this position it is arranged under the supporting plane 13 . The center of gravity of the unfolded attachment 200 located parallel to the axle unit 11 is located in front of the axle unit 11 outside of the chassis 10 .
[0043] The corn which stands on the field is cut by the front attachment 200 and transported to the drawing-in chute 41 , the corn is processed by the functional component group 40 and the produced product leaves the functional component group 40 through the lower discharge chute 46 . The upper discharge chute 48 which is directly connected with the lower discharge chute 46 transports the product for overloading in a desired direction.
[0044] The forage harvester 100 shown in FIG. 2 travels during harvesting preferably in a chopper traveling direction HF on the field. It is to be understood that the forage harvester 100 can also travel in an opposite direction backwards for ranging.
[0045] FIG. 3 shows a schematic plan view of the inventive forest harvester 100 with series-independent front attachment 200 in an upwardly folded transporting position 220 . The upwardly folded front attachment 200 is smaller than the greatest width of the forage harvester 100 .
[0046] The operator's cabin in the shown street operating position is reachable through a second right-side raising element 17 which is located between the axle units 1 1 and 12 on the supporting frame 10 .
[0047] The forage harvester 100 shown in FIG. 3 is preferably travels in a street traveling direction SF on the street. It is to be understood that the forest harvester 100 can also travel in an opposite direction backwards for ranging.
[0048] The change from the street operating positions 31 , 60 to the chopper operating positions 32 , 65 is performed in the forage harvester 100 shown in FIGS. 2 and 3 in clockwise direction, while the reverse change of the positions is performed opposite to the clockwise direction.
[0049] FIG. 4 shows a second embodiment of the turning device. The displacement guide 50 ′ is arranged around the lower discharge chute 46 on the chassis plane 13 . The operator's cabin 30 is arranged on the displacement guide 50 ′ through a straight joint arm 52 . The joint arm 52 is arranged on an inner end displaceably in the displacement guide 50 ′. The operator's cabin 30 is supported rotatably about a vertical axis of rotation 53 ′ on the outer end of the joint arm 52 . The cabin 50 is turnable around a movement center point 51 ′ which is coaxial with the axle rotation 49 of the upper discharge chute. This embodiment makes possible a complete rotation of the operator's cabin 30 around the lower discharge chute 46 , which is partially rotational and partially translatory.
[0050] During operation on a street in the street traveling direction SF the distribution of the loads and the reverse of the traveling direction in particular during braking from higher speeds are especially useful. During significant deceleration from higher speed, the weight of the axle unit 11 , the functional component group 40 and the front attachment 200 prevents lifting of the axle unit 11 of the forage harvester 100 from the street.
[0051] It is also within the spirit of the present invention that, in deviation from the shown embodiment in FIGS. 1-3 , the raised elements 16 and 17 can be arranged mirror-symmetrically on the support frame 10 and the movement directions of the cabins 30 and the upper discharge chute 48 can be reversed.
[0052] It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
[0053] While the invention has been illustrated and described as embodied in a forage harvester with a positionable operator's cabin, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
[0054] Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
[0055] What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.
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A self-propelled forage harvester has a chassis, an operator's cabin arranged on the chassis, a chopper drum, an ascending lower discharge chute extending from the chopper drum inside the chassis to a level above the chassis, and a working element arrangement, the operator's cabin being movable from a street operating position into at least one chopper operating position and vice versa and the cabin embracing the at least one working element arrangement during movements between the positions.
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BACKGROUND
RELATED APPLICATIONS
The present application is related to U.S. Non-Provisional application Ser. No. 12/577,608, U.S. Provisional Application Ser. No. 61/111,465, and U.S. Provisional Application Ser. No. 61/221,339. The present application incorporates by reference in their entirety each of the foregoing applications.
1. Field
This disclosure is generally related to an Ethernet Passive Optical Network (EPON). More specifically, this disclosure is related to power-saving features of the EPON.
2. Related Art
In order to keep pace with increasing Internet traffic, network operators have widely deployed optical fibers and optical transmission equipment, substantially increasing the capacity of backbone networks. A corresponding increase in access network capacity, however, has not matched this increase in backbone network capacity. Even with broadband solutions, such as digital subscriber line (DSL) and cable modem (CM), the limited bandwidth offered by current access networks still presents a severe bottleneck in delivering large bandwidth to end users.
Among different competing technologies, passive optical networks (PONs) are one of the best candidates for next-generation access networks. With the large bandwidth of optical fibers, PONs can accommodate broadband voice, data, and video traffic simultaneously. Such integrated service is difficult to provide with DSL or CM technology. Furthermore, PONs can be built with existing protocols, such as Ethernet and ATM, which facilitate interoperability between PONs and other network equipment.
Typically, PONs are used in the “first mile” of the network, which provides connectivity between the service provider's central offices and the premises of the customers. The “first mile” is generally a logical point-to-multipoint network, where a central office serves a number of customers. For example, a PON can adopt a tree topology, wherein one trunk fiber couples the central office to a passive optical splitter/combiner. Through a number of branch fibers, the passive optical splitter/combiner divides and distributes downstream optical signals to customers and combines upstream optical signals from customers (see FIG. 1 ). Note that other topologies, such as ring and mesh topologies, are also possible.
Transmissions within a PON are typically performed between an optical line terminal (OLT) and optical network units (ONUs). The OLT generally resides in the central office and couples the optical access network to a metro backbone, which can be an external network belonging to, for example, an Internet service provider (ISP) or a local exchange carrier. The ONU can reside in the residence of the customer and couples to the customer's own home network through a customer-premises equipment (CPE).
In the example of an Ethernet PON (EPON), communications can include downstream traffic and upstream traffic. In the following description, “downstream” refers to the direction from an OLT to one or more ONUs, and “upstream” refers to the direction from an ONU to the OLT. In the downstream direction, because of the broadcast nature of the 1×N passive optical coupler, data packets are broadcast by the OLT to all ONUs and are selectively extracted by their destination ONUs. Moreover, each ONU is assigned one or more Logical Link Identifiers (LLIDs), and a data packet transmitted by the OLT typically specifies an LLID of the destination ONU. In the upstream direction, the ONUs need to share channel capacity and resources, because there is only one link coupling the passive optical coupler to the OLT.
FIG. 1 illustrates a passive optical network including a central office and a number of customers coupled through optical fibers and a passive optical splitter (prior art). A passive optical splitter 102 and optical fibers couple the customers to a central office 101 . Passive optical splitter 102 can reside near end-user locations to minimize the initial fiber deployment costs. Central office 101 can couple to an external network 103 , such as a metropolitan area network operated by an Internet service provider (ISP). Although FIG. 1 illustrates a tree topology, a PON can also be based on other topologies, such as a logical ring or a logical bus. Note that, although in this disclosure many examples are based on EPONs, embodiments of the present invention are not limited to EPONs and can be applied to a variety of PONs, such as ATM PONs (APONs) and wavelength division multiplexing (WDM) PONs.
As the popularity of EPONs increases, the number of deployed ONUs also increases. As a result, the power consumption of each GNU can no longer be ignored, and adding power-saving features to ONU design becomes increasingly important. Because of the bursty nature of the network traffic, the ONU, or at least part of the ONU, often remains inactive for a period of time. For example, the transmitter of the ONU might remain inactive unless the user is sending data packets upstream, and the receiver of the ONU might remain inactive unless the user is receiving downstream traffic. Other parts of the ONU, such as the components responsible for packet processing, media access control (MAC), error correction, etc., also may remain idle when no data traffic occurs. These idling components might consume a significant amount of power. Moreover, EPONs increasingly are carrying critical services, such as voice-over-IP (VoIP) and video data, to users. Hence, it is important to prevent any dropping of traffic and to make sure the ONU is ready to operate when needed.
SUMMARY
According to an embodiment, there is provided a system for reducing power consumption in a Passive Optic Network (PON). The system may comprise an optical network unit (ONU) and an optical line terminal (OLT). The ONU may be configured to operate in a first mode and a second mode of operation. The OLT coupled to the ONU may be configured to instruct the ONU to operate in the first mode of operation based on a type of traffic in an upstream traffic or a downstream traffic. Additionally, the OLT may be configured to buffer the downstream traffic to the ONU and disable a queue for the downstream traffic during the first mode of operation.
According to another embodiment, there is provided an example method for reducing power consumption in a Passive Optic Network (PON). The method may include operating an ONU in a first mode or a second mode of operation. In addition, the method may include instructing the ONU, using an optical line terminal (OLT), to operate in the first mode of operation based on a type of traffic in an upstream traffic or a downstream traffic. The method may then include buffering the downstream traffic to the ONU and disabling a queue for the downstream traffic during the first mode of operation.
According to another embodiment, a system may comprise a first network equipment and a second network equipment that may be coupled to the first network equipment. The second network equipment may be configured to enable a first mode or a second mode of operation of the first network equipment based on a status of traffic. During the first mode of operation, the second network equipment may be configured to buffer a downstream traffic to the first equipment and disable a queue for the downstream traffic.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 presents a diagram illustrating a PON wherein a central office and a number of customers are coupled through optical fibers and a passive optical splitter (prior art).
FIG. 2 presents a block diagram illustrating the architecture of an exemplary OLT in accordance with an embodiment of the present invention.
FIG. 3 presents a state diagram illustrating an ONU sleep cycle in accordance with an embodiment of the present invention.
FIG. 4 presents a diagram illustrating the status of the OLT and the ONU during the ON and OFF time of a sleep cycle in accordance with an embodiment of the present invention.
FIG. 5 presents a flow chart illustrating the process of a sleep cycle in accordance with an embodiment of the present invention.
FIG. 6 presents a block diagram illustrating the architecture of an exemplary ONU in accordance with an embodiment of the present invention.
FIG. 7 presents a flow chart illustrating a process of an ONU going to sleep mode in accordance with one embodiment of the present invention.
In the figures, like reference numerals refer to the same figure elements.
DETAILED DESCRIPTION
The following description is presented to enable any person skilled in the art to make and use the embodiments, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. Thus, the present invention is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
Overview
To save power consumed by an ONU, it is desirable for the ONU to power down, at least partially, during idling time periods or to power down its idling components. In addition to powering down (“going to sleep”), the ONU also needs to be able to turn on (“wake up”) when it is no longer in the idle mode. Embodiments of the present invention provide a system that can select an ONU to be placed in a sleep cycle based on the ONU's traffic status. The system can power down the entire or part of the ONU or the transmitter of the ONU when link traffic is light and no time-critical traffic is detected. In one embodiment, the ONU “wakes up” when traffic is detected. To avoid traffic loss, in some embodiments, the upstream and downstream traffic are buffered by the ONU and the OLT, respectively.
Sleep Cycles
In some embodiments, the OLT monitors traffic status of all ONUs and determines their sleep eligibility. An ONU can be eligible for entering sleep cycles if the ONU traffic is low and no time-critical traffic is present. For example, this would be the case when the ONU traffic only contains Operations, Administration, and Management (OAM) traffic, Internet Control Message Protocol (ICMP), or spanning traffic. FIG. 2 presents a block diagram illustrating the architecture of an exemplary OLT in accordance with an embodiment of the present invention. An OLT 200 includes a lookup engine 202 , a power-management module 204 , and an OAM module 206 .
During operation, OLT lookup engine 202 can characterize the traffic on the upstream and downstream links using rule-based statistics. The OLT selects ONUs for entering sleep cycles based on the characterized ONU traffic. For example, if the OLT determines that the traffic rate to and from an ONU is low based on the statistics, and no time-critical frames/packets are present, OLT power-management module 204 can put the ONU in sleep cycles. In one embodiment, OAM module 206 generates an OAM message, which is sent to the ONU to enable an ONU to enter sleep cycles. During the ONU's sleep duration, the OLT buffers the downstream unicast and broadcast traffic, while continues to transmit the multicast traffic downstream. Note that the rule-based statistics only increment for application traffic, such as VoiP or video data, and remain unchanged for network management traffic. Hence, although the ONU may detect the presence of upstream traffic, the OLT can still determine whether to put the ONU in sleep cycles based on the types of traffic received from the ONU.
The ONU sleep cycles define an ON and OFF time for the ONU. During the OFF time, one or more ONU components can be placed in sleep mode (powered down), and the sleeping-ONU buffers all upstream transmissions. In one embodiment, the ONU selected for sleep cycle also checks whether it has joined a multicast group. If the ONU determines that it has joined a multicast group, the ONU powers down only its transmitting path including the ONU transmitter and its associated control circuit. In contrast, if the ONU determines that the ONU does not have a multicast group joined, the ONU powers down both its transmitting and receiving paths. Note that in order to power down its transmitting and receiving path independently, the ONU includes separate controls for transmitter and receiver power. In a further embodiment, the high-speed serial interface, such as a SerDes, is also put in sleep mode in addition to the ONU transmitter and/or receiver.
Note that one important feature of the sleep mode is to ensure that no traffic is lost while the ONU is in sleep mode. Hence, proper packet buffering is needed. In one embodiment, the OLT buffers all broadcast traffic if the OLT determines that one or more of the coupled ONUs are in sleep mode. The OLT delays transmission of broadcast traffic until all coupled ONUs are awake. In addition, the OLT also buffers unicast traffic destined to the ONU in sleep mode. In the meantime, the ONU buffers upstream traffic.
In one embodiment, the OLT sends a message to the ONU to start the sleep cycle with a timer. Once the timer has expired, the ONU enables the transceiver interface and resumes normal transmit and receive functions. FIG. 3 presents a state diagram illustrating an ONU sleep cycle in accordance with an embodiment of the present invention. During normal operation, OLT 300 transmits unicast frames to ONUs 302 and 340 (operation 304 ), Internet Protocol (IP) multicast frames to ONU 340 (operation 306 ), and broadcast frames to ONUs 302 and 340 (operations 308 ). Based on traffic status, OLT 300 selects ONU 302 and ONU 340 for entering a sleep cycle (operation 310 ). To prepare for ONUs 302 and 340 to enter the sleep mode, OLT 300 disables its downstream unicast queues holding traffic for ONUs 302 and 340 as well as its broadcast queue (operation 312 ). Subsequently, OLT 300 sends an OAM message to ONUS 302 and 340 (operation 314 ). In one embodiment, the OAM message includes a time indicating the time period ONUs 302 and 340 should remain in sleep mode. In one embodiment, ONUs 302 and 340 receive separate OAM messages. Upon receiving the “go to sleep” OAM message, ONU 302 determines that it does not belong to any multicast group (operation 316 ), powers down its transceiver, and buffers its upstream traffic (operation 318 ). At the same time, ONU 340 determines that it belongs to a multicasting group (operation 317 ). As a result, ONU 340 powers down its transmitting path, and buffers its upstream traffic (operation 319 ). While ONUs 302 and 340 remain in the sleep mode, OLT 300 buffers all broadcast frames and unicast frames for ONUs 302 and 340 , and continues to transmit multicast frames to ONU 340 (operation 320 ). Note that ONU 302 does not belongs to the multicast group that includes ONU 340 .
Once ONU 302 's sleep timer and ONU 340 ′s sleep timer expire (operation 324 and 325 ), ONU 302 powers up its entire optical path (operation 326 ), and ONU 340 powers up its transmitting path (operation 327 ). OLT 300 enables its downstream unicast queue to ONUs 302 and 340 , and floods broadcast LLID by transmitting all delayed broadcast frames (operation 328 ). Subsequently, OLT 300 resumes normal transmission by transmitting unicast frames, IP multicast frames, and broadcast frames to ONUs 302 and 340 (operations 330 - 334 ).
FIG. 4 presents a diagram illustrating the status of the OLT and the ONU during the ON and OFF time of a sleep cycle in accordance with an embodiment of the present invention. OLT 400 includes a number of queues including unicast queues, such as queues 402 - 406 , multicast queues, such as queue 408 , and a broadcast queue 410 . OLT 400 couples to a number of downstream ONUs, including ONUs 414 - 418 , via a passive optical splitter 412 . OLT unicast queues 402 , 404 , and 406 stores unicast traffic destined to ONU 414 , 416 , and 418 , respectively. Each ONU includes a transmitter, a receiver, an ONU chip that includes a high-speed interface, and an Ethernet physical layer (PHY) interface. For example, ONU 414 includes a transmitter 420 , a receiver 422 , an ONU chip 424 which includes a serializer/deserializer (SERDES) 426 , and a PHY interface 428 .
During operation, OLT 400 determines which ONU is eligible to be placed in sleep mode. ONU 414 is active by transmitting upstream and receiving downstream traffic, and is not eligible for sleep. ONU 416 only receives downstream multicasting traffic, thus being eligible for sleep. For example, the subscriber might be watching TV. ONU 418 exhibits low traffic bandwidth, thus also being eligible for sleep.
During the wake time (the ON time) of a sleep cycle, all queues in OLT 400 are enabled, and all ONUs are powered up including the ONUs' transmitting and receiving paths. In one embodiment, the ONU wake time is set as 30 ms. During the power down time (the OFF time) of the sleep cycle. ONUs 416 and 418 are placed in the sleep mode. Accordingly, OLT 400 disables its unicast queues 404 and 406 , and its broadcast queue 410 . Because ONU 416 receives multicasting traffic, ONU 416 only powers down its transmitting path. ONU 418 powers down both of its transmitting and receiving path. In addition, ONU 418 may powers down its SERDES. In one embodiment, the power down time is set for 200 ms.
FIG. 5 presents a flow chart illustrating the process of a sleep cycle in accordance with an embodiment of the present invention. At the beginning of the sleep cycle, the OLT determines whether the ONU is eligible for sleep (operation 500 ). If not, the ONU is skipped for this sleep cycle (operation 502 ). Otherwise, the OLT disables its downstream broadcast queue and unicast queue for the ONU to disable downstream broadcast and unicast traffic (operation 504 ), and sends a sleep message to the ONU (operation 506 ). Upon receiving the sleep message, the ONU determines whether it has joined any multicast group (operation 508 ). If so, the ONU powers down its upstream transmit optical path component, such as a transmitter, and disables its upstream traffic to the OLT (operation 510 ). During sleep, the ONU determines whether an “early-wake” condition is met (operation 511 ). In one embodiment, the “early-wake” conditions include, but are not limited to: time-critical upstream traffic detected, new multicast group joined (such as IPTV channel change is detected), an alarm condition (e.g., dying gasp alarm), and that an upstream queue has crossed certain threshold. If so, the ONU initializes an “early-wake” operation by powering up its upstream optical path components and enables upstream traffic to the OLT (operation 514 ). If not, the ONU determines whether its sleep timer is expired (operation 512 ). Note that the sleep time defines a time period that the ONU stays power down. If so, the ONU powers up its upstream optical path components and enables upstream traffic to the our (operation 514 ). Otherwise, the system returns to operation 511 .
If the ONU determines that it has not joined a multicast group (operation 508 ), the ONU powers down its upstream and downstream optical path components, such as a transmitter and a receiver, and disables upstream traffic to the OLT (operation 516 ). During sleep, the ONU determines whether an “early-wake” condition is met (operation 517 ). If so, the ONU initializes an “early-wake” operation by powering up all of its optical path components and enables traffic to and from the OLT (operation 520 ) If not, the ONU further determines whether its sleep timer is expired (operation 518 ). If so, the ONU powers up all of its optical path components and enables traffic to and from the OLT (operation 520 ). Otherwise, the system returns to operation 517 .
After the ONU power up, the OLT enables its unicast and broadcast queues to enable its downstream transmission to the ONU (operation 522 ). The OLT then waits for its wakeup timer to expire (operation 524 ). Note that the wakeup timer defines a time period that the ONU stays awake. After the expiration of the wakeup timer, a new sleep cycle can start.
The maximum time for an ONU to remain in the sleep mode can be limited by the buffer capacity of the OLT and the ONU and other user considerations. There is a tradeoff between the amount of power saved and the risk of losing user traffic or delay of user applications. If the time interval between two sleep cycles (corresponding to a maximum sleep time) is too short, the amount of power saved can be limited. On the other hand, a longer time interval between two consecutive sleep cycles increases the risk of the loss of user traffic due to OLT or ONU buffer overflow.
In addition to the maximum sleep time, the ONU can also notify the OLT of its minimum sleep time. The minimum sleep time of the ONU may be determined by the turn-on time of its transmitter (the time required for the transmitter to stabilize after power-on). If the OLT determines that the time interval between the ONU power-off and the next scheduled ONU wake-up is less than the minimum ONU sleeping time, the OLT may prevent the ONU from entering the sleep mode. Note that the turn-on time of the ONU transmitter is determined by the type of lasers used, and the ONU can notify the OLT about such a parameter via an OAM message or a multipoint control protocol (MPCP) extension message. In addition to using the laser turn-on time to set the ONU minimum sleep time, in one embodiment, the OLT is configured to take into consideration the laser turn-on time when scheduling its transmission after a downstream ONU wakes up. For example, if an ONU is scheduled to come out of sleep mode at a time t 0 , and the OLT knows the turn-on time of the ONU laser is Δt, then the OLT will schedule the ONU's upstream transmission at a time later than t 0 +Δt.
It is also possible to allow the ONU to synchronize its power-down cycle with the MPCP ONU-polling cycle, which can be adaptively adjusted based on the ONU traffic status. In one embodiment, the OLT periodically polls the ONU for its status. If the ONU reports no traffic within one ONU polling cycle, the OLT can instruct the ONU to “go to sleep” or to power down until the scheduled time for the next ONU polling. Furthermore, the OLT can decrease the ONU polling rate, or increase the waiting time before the next ONU polling, if the ONU reports no traffic at a following polling time. Once the ONU reports the presence of traffic, the OLT instructs the ONU to “wake up,” and resumes its original ONU polling rate.
Note that, because the ONU monitors and reports traffic at each polling time, alternatively the ONU can wake up on its own without receiving an instruction from the OLT. In certain cases, one ONU is assigned with multiple LLIDs all sharing the same transmitter and receiver. In order to save power, the OLT can group the multiple LLIDs together, and send a REPORT for these LLIDs in the same polling cycle. The OLT instructs the ONU to enter sleep mode if all LLIDs report zero traffic.
Sleep/Wake Up on Detection
In some embodiments, the system determines whether to allow the ONU to enter sleep mode based on the ONU monitoring the user traffic, FIG. 6 presents a block diagram illustrating the architecture of an exemplary ONU in accordance with an embodiment of the present invention. In FIG. 6 , an ONU 600 includes an optical interface 602 for coupling to an optical fiber, an optical bi-directional transceiver 604 coupled to optical interface 602 , a Serializer/Deserializer (SerDes) 610 , a traffic-detection module 612 , a power-management module 614 , a user-to-network interface (UNI) 616 for receiving user data, and an ONU chip 618 which is implemented in an application-specific integrated circuit (ASIC).
Optical bi-directional transceiver 604 includes an optical transmitter 606 and an optical receiver 608 . Through optical interface 602 , optical transmitter 606 transmits optical signals to the optical fiber and optical receiver 608 receives optical signals from the same optical fiber. A high-speed serial interface, such as a SerDes 610 is coupled to optical transceiver 604 .
Traffic-detection module 612 can detect the status of the UNI link coupled to UNI 616 . For example, if no Ethernet cable is plugged in UNI 616 , traffic-detection module 612 detects that the UNI link is down. In such a case, ONU 600 can go into sleep mode since it is not in use. In one embodiment, ONU 600 goes into sleep mode by powering down a number of components including transmitter 606 , receiver 608 , SerDes 610 , ONU chip 618 , and other components that may consume power. However, while in sleep mode, ONU 600 is still able to monitor the link status of UNI 616 . For example, traffic-detection module 612 can remain awake while the rest of ONU 600 goes into sleep mode. Once the link status of UNI 616 is up, such as an Ethernet cable being plugged in UNI 616 , ONU 600 is able to come out of the sleep mode (wake up).
In addition to detecting the UNI link status, traffic-detection module 612 can also detect whether ONU 600 is receiving any upstream traffic from the user via UNI 616 . In one embodiment, if it is determined that ONU 600 has not received any upstream traffic for a certain amount of time, power-management module 614 can put transmitter 606 and its associated control circuit in sleep mode. Note that in such a case the OLT still keeps ONU 600 registered although the OLT is not receiving reports back from ONU 600 for polling. When traffic-detection module 612 detects the presence of upstream traffic, power-management module 614 wakes up transmitter 606 and its associated control circuit. Transmitter 606 then starts to transmit traffic upstream to the OLT.
To avoid multicast traffic loss, in one embodiment, traffic-detection module 612 also detects the presence of multicast traffic by detecting whether ONU 600 has joined a multicast group. If it is determined that ONU 600 does not belong to any multicast group, power-management module 614 can put receiver 608 in sleep mode. While ONU 600 is in sleep mode, traffic-detection module 612 continues to detect whether ONU 600 joins a multicast group, and if traffic-detection module 612 detects a new multicast join, ONU 600 will be brought out of sleep mode.
FIG. 7 presents a flow chart illustrating a process of an ONU going to sleep mode in accordance with one embodiment of the present invention. During operation, the ONU (periodically) monitors its upstream traffic (operation 702 ), and determines whether upstream traffic is present (operation 704 ). If no upstream traffic is present, the ONU transmitter enters sleep mode (operation 706 ). The ONU also detects whether multicast traffic is present (operation 708 ), and if not, the ONU receiver enters sleep mode (operation 710 ).
In one embodiment, when the only traffic received by an ONU in sleep mode is network management traffic, such as simple network management protocol (SNMP) messages, spanning tree protocol (STP) messages, Internet control message protocol (ICMP) messages, etc., and no application data, such as VoiP and video, is present, the ONU can periodically wake up to process downstream broadcast and any management packets, and then go back to sleep afterward.
In some embodiments, the ONU also includes a power meter that measures the ONU's power usage. The power meter can measure the ONU's power usage during its wake and sleep times, and calculate an estimate of the power consumed by the ONU. In one embodiment, the ONU can report its power usage statistics to the OLT via an OAM message or a simple network management protocol (SNMP) message.
In some embodiments, the network management system (NMS) has the ability to enable/disable the power-saving feature of each individual ONUs. In addition, the power-management module reports to the NMS the total time an ONU has been placed in the sleep mode as well as the amount of power saved during such time period. Based on such statistics, the NMS may decide to enable/disable the power-saving feature of the ONU. Moreover, the NMS can configure the traffic-detection module by selecting the types of traffic that can be buffered and processed later when an ONU is in the sleep mode.
The data structures and code described in this detailed description are typically stored on a computer-readable storage medium, Which may be any device or medium that can store code and/or data for use by a computer system. The computer-readable storage medium includes, but is not limited to, volatile memory, non-volatile memory, magnetic and optical storage devices such as disk drives, magnetic tape, CDs (compact discs), DVDs (digital versatile discs or digital video discs), or other media capable of storing computer-readable media now known or later developed.
The methods and processes described in the detailed description section can be embodied as code and/or data, which can be stored in a computer-readable storage medium as described above. When a computer system reads and executes the code and/or data stored on the computer-readable storage medium, the computer system performs the methods and processes embodied as data structures and code and stored within the computer-readable storage medium.
Furthermore, the methods and processes described above can be included in hardware modules. For example, the hardware modules can include, but are not limited to, application-specific integrated circuit (ASIC) chips, field-programmable gate arrays (FPGAs), and other programmable-logic devices now known or later developed. When the hardware modules are activated, the hardware modules perform the methods and processes included within the hardware modules.
The foregoing descriptions of various embodiments have been presented only for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention.
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A system and method for reducing power consumption in a Passive Optic Network (PON). The system comprises an optical line terminal (OLT), an optical network unit (ONU), a traffic-detection module configured to detect status of traffic to and from the ONU, and a power-management module configured to place the ONU in sleep mode based on the detected traffic status. The ONU includes transmitting and receiving components that are selectively powered down during the sleep mode based on a type of traffic in the ONU.
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BACKGROUND OF THE INVENTION
The present invention relates to a phase splitter which is utilized in a modulator and a demodulator of QPSK(=Quadrature Phase Shift Keying), and more particularly to a 90 degrees phase splitter for splitting a phase by converting a voltage source to be phase-shifted into a current source.
Generally, the same 90 degrees phase splitters are used in the QPSK modulator and demodulator.
Conventionally, as shown in FIG. 1, a signal outputted from a voltage source V s passes through resistors R 1 and R 2 , and capacitors C 1 and C 2 .
Then, a first and a second output voltages V 1 and V 2 are produced via a first and a second output means.
Here, the first and the second output voltages are represented as follows: ##EQU1##
In the equations (1) and (2), when a relationship of R 1 =R 2 [Ω] between the resistors is met, a relationship of C 1 =C 2 [farad] between the capacitors is met and a frequency f is equal to 1/2πRC, an angular frequency w meets a relationship of w=2πf=1/R 1 C 1 =1/R 2 C 2 .
Thus, the equations (1) and (2) are represented as follows: ##EQU2##
Therefore, a relationship of V 2 =jV 1 is formed, accordingly a first and a second output voltages V 1 and V 2 which have the same magnitudes but differ in phase by 90 degrees each other are obtained. However, in a prior 90 degrees phase splitter using a voltage source, when a value of an inherent impedance of the voltage source is large, it is difficult to perform to phase-split accurately by 90 degrees, as well as when a driving voltage V s is small, it is pointed out as a defect that each of output voltages of the phase splitter is small.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a phase splitter for facilitating to phase-split by 90 degrees by converting a driving voltage source into a driving current source, in order to solve the above-mentioned defect.
Therefore, in order to achieve the above-mentioned object, there is provided a phase splitter according to the present invention, comprising a voltage source working as a driving signal source;
a voltage to current converting means for converting the driving voltage source into a driving current source; and
a first and a second output means connected in parallel each other which are connected in series to the voltage to current converting means and for outputting output voltages which differ in phase each other but have the same magnitudes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing a 90° phase splitter of the prior art.
FIG. 2 is a block diagram showing a 90° phase splitter according to the present invention.
FIG. 3 is a circuit diagram showing an exemplary embodiment of the present invention.
FIG. 4 is a circuit diagram showing another embodiment of the present invention.
FIG. 5 is an equivalent circuit diagram of the transistor utilized in the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will be described below in detail with respect to the accompanying drawings.
Referring to FIG. 2, a phase splitter according to the present invention comprises a voltage/current converting means 20 for converting a driving voltage Vs outputted from a voltage source 10 working as a driving signal source. The output terminal of this voltage/current converting means 20 is connected to a first and a second output means 30 and 40 for supplying output voltages which have same magnitudes but differ in phase each other. This voltage/current converting means 20 may be composed of a transistor device TR. Referring to FIG. 3, the driving voltage source Vs is connected to a base electrode B of the transistor TR. An emitter electrode of the transistor TR is grounded via a resistor R3. Also, a collector electrode C of the transistor TR is connected in series to a first output means 30 and a second output means 40 which are connected in parallel each other.
The operation of the transistor TR used for the voltage/current converting means 20 will be described below with respect to FIG. 5.
Referring to FIG. 5 showing an equivalent circuit diagram of the transistor TR, when the voltage source Vs having an inherent impedance R is connected between the base electrode B and the emitter electrode of the transistor TR, the current Ic flowing in the collector electrode C is represented as a base-emitter voltage V BE multiplied by a shot-circuit mutual conductance gm.
That is, a relationship of the following equation (3) is formed.
Ic=-gmV.sub.BE (3)
Thus, the present invention utilizes a transistor TR, thereby obtaining a function that the voltage source Vs is converted into a current source.
Next, as shown in FIG. 3, the collector electrode C of the transistor TR is connected to the first and the second output means 30 and 40.
The first output means 30 is composed of a reactor L 1 and a resistor R 1 which are connected in series with each other, and the second output means 40 is composed of a resistor R 2 and a reactor L 2 which are connected in series with each other.
Here, a first output voltage V 2 which is outputted through a point between the reactor L 1 and the resistor R 1 , and a second output voltage V 2 which is outputted through a point between the resistor R 2 and the reactor L 2 are represented as follows: ##EQU3## in which, V 0 indicates a voltage of the collector electrode c of the transistor TR.
In the equations (4) and (5), when a frequency f is equal to 1/2π×(Ri/Li) (i=1,2), the angular frequency w is equal to 2πf=Ri/Li=R 1 /L 1 =R 2 /L 2 .
Thus, substituting a value of the angular frequency w into the equations (4) and (5), the following relationships of V 1 and V 2 are obtained.
That is, ##EQU4## are obtained, accordingly the first output voltage V 1 and the second output voltage V 2 are identical in magnitude and differ in phase by 90 degrees each other. In addition, the phase splitter according to the present invention utilizes an amplifying function of the transistor TR, accordingly even if the small driving voltage Vs is applied to the base electrode of the transistor TR, relatively large output voltages V 1 and V 2 are obtained.
On the one hand, FIG. 4 shows a circuit diagram of another embodiment of the present invention.
Referring to FIG. 4, transistors TR 1 and TR 2 based on the functions of differential amplification are connected to a first output means 30 comprising a resistor R 1 and a reactor L 1 , and a second output means 40 comprising a resistor R 2 and a reactor L 2 , respectively.
Here, the alternate currents flowing in the first and the second output means 30 and 40 comprising a resistor and a reactor, respectively, are identical in magnitude but opposite in phase with each other. When the collector current of the transistor TR 1 is I[A], the first and the second output voltages V 1 and V 2 are represented as follows:
V.sub.1 =R.sub.1 I (6)
V.sub.2 =-jwL.sub.2 I (7)
Here, if the relationships of w=R/L=R 1 /L 1 =R 2 , R 1 =R 2 and L 1 =L 2 are satisfied, the relationship of V2=-jV 1 is obtained from the equations (6) and (7).
Thus, the first output voltage V 1 and the second output voltage V 2 are same in magnitude and differ in phase by 90 degrees each other.
At this time, it can be seen that the present invention effects upon an improvement of a common mode rejection ratio through using features of differential amplifiers.
As described above, the present invention utilizes a transistor, thereby converting a voltage source as a driving signal source into a current source outputted from its collector electrode.
Accordingly, the present invention utilizes reactors instead of using capacitors, and obtains a large output voltage with a small driving voltage through an amplification function of transistor.
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Disclosed is a 90-degree phase splitter utilized in QPSK modulator and demodulator. The 90-degree phase splitter uses a transistor thereby converting a voltage source into a current source, and accordingly obtains two outputs having same in magnitude but different in phase by 90 degrees through output circuits comprising reactors and resistors.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to computer systems and, more particularly, to a method of improving the performance of a cache used by a processor of a computer system.
2. Description of the Related Art
The basic structure of a conventional computer system 10 is shown in FIG. 1. Computer system 10 may have one or more processing units, two of which 12a and 12b are depicted, which are connected to various peripheral devices, including input/output (I/O) devices 14 (such as a display monitor, keyboard, and permanent storage device), memory device 16 (such as random access memory or RAM) that is used by the processing units to carry out program instructions, and firmware 18 whose primary purpose is to seek out and load an operating system from one of the peripherals (usually the permanent memory device) whenever the computer is first turned on. Processing units 12a and 12b communicate with the peripheral devices by various means, including a generalized interconnect or bus 20. Computer system 10 may have many additional components which are not shown, such as serial and parallel ports for connection to, e.g., modems or printers. Those skilled in the art will further appreciate that there are other components that might be used in conjunction with those shown in the block diagram of FIG. 1; for example, a display adapter might be used to control a video display monitor, a memory controller can be used to access memory 16, etc. Also, instead of connecting I/O devices 14 directly to bus 20, they may be connected to a secondary (I/O) bus which is further connected to an I/O bridge to bus 20. The computer can have more than two processing units.
In a symmetric multi-processor (SMP) computer, all of the processing units are generally identical, that is, they all use a common set or subset of instructions and protocols to operate, and generally have the same architecture. A typical architecture is shown in FIG. 1. A processing unit includes a processor core 22 having a plurality of registers and execution units, which carry out program instructions in order to operate the computer. An exemplary processing unit includes the PowerPC™ processor marketed by International Business Machines Corp. The processing unit can also have one or more caches, such as an instruction cache 24 and a data cache 26, which are implemented using high-speed memory devices. Caches are commonly used to temporarily store values that might be repeatedly accessed by a processor, in order to speed up processing by avoiding the longer step of loading the values from memory 16. These caches are referred to as "on-board" when they are integrally packaged with the processor core on a single integrated chip 28. Each cache is associated with a cache controller (not shown) that manages the transfer of data between the processor core and the cache memory.
A processing unit 12 can include additional caches, such as cache 30, which is referred to as a level 2 (L2) cache since it supports the on-board (level 1) caches 24 and 26. In other words, cache 30 acts as an intermediary between memory 16 and the on-board caches, and can store a much larger amount of information (instructions and data) than the on-board caches can, but at a longer access penalty. For example, cache 30 may be a chip having a storage capacity of 256 or 512 kilobytes, while the processor may be an IBM PowerPC™ 604-series processor having on-board caches with 64 kilobytes of total storage. Cache 30 is connected to bus 20, and all loading of information from memory 16 into processor core 22 usually comes through cache 30. Although FIG. 1 depicts only a two-level cache hierarchy, multi-level cache hierarchies can be provided where there are many levels of interconnected caches.
A cache has many "blocks" which individually store the various instructions and data values. The blocks in any cache are divided into groups of blocks called "sets" or "congruence classes." A set is the collection of cache blocks that a given memory block can reside in. For any given memory block, there is a unique set in the cache that the block can be mapped into, according to preset mapping functions. The number of blocks in a set is referred to as the associativity of the cache, e.g. 2-way set associative means that for any given memory block there are two blocks in the cache that the memory block can be mapped into; however, several different blocks in main memory can be mapped to any given set. A 1-way set associate cache is direct mapped, that is, there is only one cache block that can contain a particular memory block. A cache is said to be fully associative if a memory block can occupy any cache block, i.e., there is one congruence class, and the address tag is the full address of the memory block.
An exemplary cache line (block) includes an address tag field, a state bit field, an inclusivity bit field, and a value field for storing the actual instruction or data. The state bit field and inclusivity bit fields are used to maintain cache coherency in a multiprocessor computer system (indicate the validity of the value stored in the cache). The address tag is a subset of the full address of the corresponding memory block. A compare match of an incoming address with one of the tags within the address tag field indicates a cache "hit." The collection of all of the address tags in a cache (and sometimes the state bit and inclusivity bit fields) is referred to as a directory, and the collection of all of the value fields is the cache entry array.
When all of the blocks in a congruence class for a given cache are full and that cache receives a request, whether a "read" or "write," to a memory location that maps into the full congruence class, the cache must "evict" one of the blocks currently in the class. The cache chooses a block by one of a number of means known to those skilled in the art (least recently used (LRU), random, pseudo-LRU, etc.) to be evicted. If the data in the chosen block is modified, that data is written to the next lowest level in the memory hierarchy which may be another cache (in the case of the L1 or on-board cache) or main memory (in the case of an L2 cache, as depicted in the two-level architecture of FIG. 1). By the principle of inclusion, the lower level of the hierarchy will already have a block available to hold the written modified data. However, if the data in the chosen block is not modified, the block is simply abandoned and not written to the next lowest level in the hierarchy. This process of removing a block from one level of the hierarchy is known as an "eviction". At the end of this process, the cache no longer holds a copy of the evicted block.
FIG. 2 illustrates the foregoing cache structure and eviction process. A cache 40 (L1 or a lower level) includes a cache directory 42, a cache entry array 44, an LRU array 46, and control logic 48 for selecting a block for eviction from a particular congruence class. The depicted cache 40 is 8-way set associative, and so each of the directory 42, cache entry array 44 and LRU array 46 has a specific set of eight blocks for a particular congruence class as indicated at 50. In other words, a specific member of the congruence class in cache directory 42 is associated with a specific member of the congruence class in cache entry array 44 and with a specific member of the congruence class in LRU array 46, as indicated by the "X" shown in congruence class 50.
Each of the blocks in directory 42 are connected to the control logic via an error correction code (ECC) circuit 52. A bit in a given cache block may contain an incorrect value, either due to a soft error (such as stray radiation or electrostatic discharge) or to a hard error (a defective cell). ECCs can be used to reconstruct the proper data stream. Some ECCs can only be used to detect and correct single-bit errors, i.e., if two or more bits in a particular block are invalid, then the ECC might not be able to determine what the proper data stream should actually be, but at least the failure can be detected. Other ECCs are more sophisticated and even allow detection or correction of double errors. These latter errors are costly to correct, but the design tradeoff is to halt the machine when double-bit errors occur. Although only directory 42 is shown with ECC circuits, these circuits can similarly be used with other arrays, such as cache entry array 44.
The outputs of ECC circuits 52, whose values correspond to (corrected) memory block addresses, are connected to respective comparators 54 each of which also receives the address of the requested memory block. If a valid copy of a requested memory block is in the congruence class 50, then one, and only one, of the comparators 54 will output an active signal. The outputs of comparators 54 are connected to a multiplexer 56 and also to an OR gate 58, whose output controls multiplexer 56. If a cache hit occurs (a requested address matches with an address in cache directory 42), then OR gate 58 activates multiplexer 56 to pass on a signal indicating which member of the congruence class matches the address. This signal controls another multiplexer 60 which receives inputs from each of the entries in cache entry array 44. In this manner, when a cache hit in the directory occurs, the corresponding value is passed through multiplexer 60 to a bus 62.
If a cache miss occurs, and if all of the blocks in the particular congruence class 50 already have valid copies of memory blocks, then one of the cache blocks in congruence class 50 must be selected for victimization. This selection is performed using the LRU bits for the congruence class in LRU array 46. For each cache block in the class, there are a plurality of LRU bits, for example, three LRU bits per block for an 8-way set associative cache. The LRU bits from each block in the class are provided as inputs to a decoder 64 having an 8-bit output to indicate which of the blocks is to be victimized. This output is coupled to multiplexer 56. In this manner, if OR gate 58 is not active, multiplexer 56 passes on an indication of the cache block to be used based on the outputs of decoder 64.
The ECC circuits discussed above are one way to deal with soft errors arising in memory cells. Another approach used for dealing with hard errors is to provide redundancy within the arrays (directory, LRU, cache). When a cache chip is fabricated, it can be tested to determine if there are any defective row or column lines in each of the arrays (row and column lines are tested for the entire cache, directory, and LRU. If an array is defective, a fuse can be permanently blown to indicate its defective nature. A comparison is then made inside the array for each accessed address to see if it matches with a defective address. If so, appropriate logic re-routes the address to one of many extra row and column lines formed on the chip, i.e., from redundant bit lines (columns) and word lines (rows). The number of extra bit and word lines may vary depending upon the defect rate and desired chip yield. For a low-defect (larger physical size) cache, two extra lines might be provided for every 256 regular lines, while in a high-defect (smaller physical size) cache, two extra lines might be provided for every eight regular lines.
There are several disadvantages and limitations in the foregoing cache construction. With respect to ECC circuits 52, these circuits are fairly complex and not only take up space on the chip, but further slow down processing since they are in the critical (timing) path for retrieving the cached values (either from directory or cache). The ECC circuits might allow for correction of double bit errors, but not for multiple bit errors with more than two bad bits. Another aspect of these prior art cache constructions that adds complexity and slows down processing is the arbitration logic 66 that is required to selectively interconnect the cache with the CPU, for CPU snoops, or with the system bus, for system bus snoops. This logic is again in the critical path. Such use of a single cache by two snooping devices inherently gives rise to certain other delays, such as when both the CPU and the system bus want to perform a read on the cache at the same time; the two read operations cannot be performed simultaneously, but must be serialized by the arbitration logic. The same is true for write operations.
Another disadvantage in cache construction relates to the use of bit line redundancy and word line redundance. While this technique can increase chip yield, the redundancies get directly in the critical path for array access. Extra time is required to search against defective row and column lines, and to re-direct requests that match with a defective line. So the tradeoff is a higher yield versus slower cache response. Another disadvantage is the additional physical size that must be provided for the redundant lines. In the example where two extra lines were provided for every 8 regular lines, 25% extra cache size (overhead) is required, and much of this space will never even be used. Redundant lines also do not scale particularly well, e.g., if the cache line size was doubled (from say 64 bytes to 128 bytes), the amount of silicon (chip space) required for the redundant lines will likewise double. Finally, the use of redundant lines which are used based on fuses blown in the cache is static and fairly wasteful. The availability of the redundant lines is based on the state of the cache during testing. In high density, large cache chips operating under varying conditions of junction temperature and internal voltages, defects in the cache build but these additional defective lines cannot be re-directed. Not only must numerous extra lines be provided to increase yield, but many of those lines are never even used.
In light of the foregoing, it would be desirable to provide a cache construction having improved handling of defective cache lines, including speeding up cache access and providing exceptional error correction capability. It would be further advantageous if the cache construction provided for efficient and dynamic use of all available cache lines without complicated logic circuits, and scaled appropriately to larger cache lines.
SUMMARY OF THE INVENTION
It is therefore one object of the present invention to provide an improved cache to be used by a processor of a computer system.
It is another object of the present invention to provide such a cache that efficiently uses all available cache lines without excess logic circuits in the critical path.
It is yet another object of the present invention to provide such a cache having improved handling of defects, including defect avoidance and error correction.
It is still another object of the present invention to provide such a cache having faster read access.
The foregoing objects are achieved in a method of determining if a requested memory block of a memory device is contained in a cache used by a processor of a computer system, generally comprising the steps of comparing a portion of an address associated with the requested memory block to a plurality of address tags stored in a cache directory of the cache, performing error checks on the address tags concurrently with said comparing step, supplying corrected address tags for any erroneous address tags indicated by said performing step, and comparing the portion of the address associated with the requested memory block to any corrected address tags. The error check may be a parity check of a portion of the address tag, either the entire portion, or of several subsets having a number of bits smaller than the address tag. The plurality of address tags can be stored in a redundant cache directory of the cache, and the corrected address tags are supplied by substituting corresponding address tags from the redundant cache directory. The cache construction can include control logic which provides the plurality of address tags simultaneously to a plurality of comparators and to a plurality of error checking circuits. By moving error checking out of the critical retrieval path of the cache, the present invention results in improved performance (increased speed).
The above as well as additional objectives, features, and advantages of the present invention will become apparent in the following detailed written description.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a block diagram of a prior art multiprocessor computer system;
FIG. 2 is a high level schematic diagram of a prior art, set associative cache; and
FIG. 3 is a high level schematic diagram of a set associative cache constructed in accordance with the present invention, having parity error control and a dynamic repair mask; and
FIG. 4 is a block diagram of a cache constructed in accordance with the present invention, having two redundant directories.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the figures, and in particular with reference to FIG. 3, there is depicted a high level schematic diagram of one embodiment of a set associative cache 70 constructed in accordance with the present invention. Cache 70 generally includes a cache directory 72, an LRU array 74, a repair mask 76, and control logic 78. Cache directory 72 has a plurality of address tags associated into sets, with the depicted embodiment being 8-way set associative, so each of the directory 72, LRU array 74 and repair mask 76 has a specific set of eight blocks for a particular congruence class as indicated at 80. A cache entry array (not shown) contains values associated with the address tags in directory 72.
Each block in a given congruence class of directory 72 has an output connected to a respective comparator 82, each of which receives the address of a requested memory block. If a valid copy of the requested memory block is in the congruence class 80, then one and only one of the comparators 82 will output an active signal to indicate which member of the set holds the valid copy. Each of the outputs from directory 72 is also connected to a respective parity checker 84, in parallel with the connection to a respective comparator 82. Parity checkers 84 do not perform any correction of erroneous bits, but rather are used only to indicate that an error has occurred in reading an address tag (or status bit) from directory 72. This error information is used as discussed further below. Importantly, since the parity checkers are connected in parallel with the comparators, they are out of the critical path, i.e., the parity checkers do not affect cache performance (i.e., decrease speed) because they can perform the parity checking concurrently, at the same time that the remaining logic is handling the request (of course, the parity checkers decrease speed if an error is found to have occurred, but this is the exception). Also, the parity checkers, which may use conventional parity checking techniques, are less complicated than error correction code (ECC) circuits such as are used in the prior art (compare FIG. 2) and so take up less space on the cache chip (silicon wafer). The use of offline parity checkers is shown for the cache directory, but can in addition be used by a cache entry array, rather than providing traditional ECC logic.
The outputs of comparators 82 are connected to an array of AND gates 86. Each AND gate 86 receives a single comparator output and one other output from repair mask 76. Repair mask 76 is used to indicate whether a particular block is defective (any portion of the cache line, including that portion in directory 72, the cache entry array, or LRU array 74). In this embodiment, the state of an output of repair mask 76 is active (on or high) if the corresponding cache line is valid; if a cache line is defective, the corresponding output from repair mask 78 will be inactive (off or low). In this manner, the output of any AND gate 86 will be active only if (1) the corresponding comparator 82 indicated a cache hit, and (2) the corresponding entry in repair mask 76 indicates that the line is valid. In other words, if a cache hit would occur except that the corresponding entry in repair mask 76 indicates that the line is defective, then the output of that entry in repair mask 76 will go inactive, making the output of the corresponding AND gate 86 also inactive (forcing a "miscompare"). Thus, a defective cache line will never result in a cache hit.
The outputs of AND gates 86 are fed to a multiplexer 88 and also to an OR gate 90, whose output controls multiplexer 88. If a cache hit occurs in a non-defective cache line, then OR gate 90 activates multiplexer 88 to pass on a signal to the cache entry array indicating which member of the congruence class matches the address. If a cache miss occurs, and if all of the blocks in the particular congruence class 80 already have valid copies of memory blocks, then one of the cache blocks must be selected for victimization. This selection is tentatively performed by LRU array 74, which may contain a conventional least-recently-used algorithm. The outputs of the LRU, which are indicative of which block has been tentatively selected for victimization, are connected to an alternate victim selection logic circuit 92, which also receives inputs from repair mask 76. If the tentatively selected victim is not defective, then alternate victim selection logic circuit 92 simply passes the LRU outputs to multiplexer 88 which in turns passes on the victimization information to the cache entry array. If the tentatively selected victim is defective, then alternate victim selection logic circuit 92 selects a new tentative victim. If the new tentative victim is not defective, then the corresponding information is transmitted to multiplexer 88. If the new tentative victim is also defective, then alternate victim selection logic circuit 92 repeats the process until a non-defective victim is selected. Thus, a defective cache line will never be chosen as a victim. If all of the mask bits for a given congruence class are set to indicate that all members of the class are defective, then the system can respond with a halt or other operation as would arise with a double-bit ECC error.
It can be seen that repair mask 76 is a convenient means for both keeping a defective cache line from ever indicating a cache hit and keeping a defective cache line from ever being chosen as a victim. Repair mask 76 can accordingly be used in place of the bit line redundancy and word line redundancy provided in prior art cache components. While some extra space on the cache chip is required for adding the repair mask, this space is generally negligible compared to the amount of space that is saved by eliminating redundant bit lines and word lines within the directory array, LRU array, and cache array. This advantage increases with increasing cache-line sizes, i.e., the repair mask array size doesn't grow as cache line size is scaled. Also, by using repair mask 76, all available cache lines are used, instead of some (redundant) cache lines never used, making more overall efficient use of the cache. Repair mask 76 further provides these advantages without any re-routing overhead, and without requiring "fuse-blow" for the directory array, LRU array, or cache array. This, in turn, allows significantly faster cache operation and significantly reduced manufacturing cost.
This novel method of using functional masking to bypass defects in caches eliminates the performance degradation and the silicon area increase of the standard cache defect repair method. From a functionality perspective, certain congruence classes may be effectively running 6-way or 7-way set associative (instead of the intended 8-way set associative). However, due to the statistical nature of cache behavior, this reduction in associativity for certain congruence classes is typically unnoticeable at the user level.
The use of a repair mask additionally allows for dynamic cache defect bypassing (of locations in the caches that are generating errors) by updating the repair mask real-time when the errors are detected. The cache lines may be tested initially at fabrication and any noted defects can be handled by permanently setting the value of the corresponding field in the repair mask. Thereafter, each time the computer is booted (turned on), the mask might be automatically updated based on firmware testing, as part of the boot process. Finally, the repair mask can be updated upon detection of directory parity errors, cache entry array ECC errors, or LRU errors. A hardware algorithm could be provided to set the values in the repair mask array. For example, one 2-bit field could be provided in the repair mask for each cache line. The 2-bit field may initially be set to zero, and incremented each time a error is detected on that cache line. This allows the 2-bit field to act as a counter, setting the cache line as defective only when three cumulative parity errors have been recorded for a given cache line.
In order to continue to reliably run the processor after encountering defective cache locations, when the repair mask entry associated with the line in the cache is set to indicate the line is defective, the contents of the cache at that location are flushed. Once the repair mask entry has been set, any future accesses to that cache line will be forced by the repair mask to see a miss on that line, and the line would never be re-used (victimized). This solution has practically no overhead when compared to prior art schemes, such as redundant lines. It is also particularly useful in those applications where the processors operate in harsh environments but must continue to function in the event of run-time defects.
FIG. 3 shows only a single directory 72, but a cache constructed in accordance with the present invention may have an additional directory 96 as shown in FIG. 4. Directories 72 and 96 are redundant, but directory 72 is used for CPU snoops and directory 96 is used for system bus snoops; in other words, one directory is provided for each snooping device/interconnect. This construction provides several advantages. First, if both directories are constructed with the parity checkers described in conjunction with FIG. 3, then each directory may serve as a backup to the other. In other words, when a parity error occurs, for example, on an address tag in directory 72, then the address tag may instead be read from directory 96.
If a parity error occurs, a parity error control (PEC) unit 98 such as that shown in FIG. 3 can be used to handle the error. PEC unit 98 is connected to each of the parity checkers 84, as well as to parity checkers of the other directory 96, as indicated by the connection lines at 100. When PEC unit 98 first detects a parity error from any parity checker, it forces the cache into a busy mode where requests are either retried or not acknowledged, until the error is handled. PEC unit 98 then reads the address tag (and the status bits) from the designated block in the other (non-error producing) directory, and supplies this address tag to the problem directory, i.e., directly to the appropriate comparator 82. After updating the problem array, PEC unit 82 allows the cache to resume normal operations.
One particularly advantageous aspect of the PEC and parity checkers of the present invention is that they may be used to provide a form of multiple-bit error detection and correction. A particular value (address tag) can be broken up into several portions, such as dividing up a 24 bit address tag into three 8-bit bytes. A parity bit is then provided for each portion, i.e., three parity bits per address tag in this example. If one bit in each portion has an erroneous value, then the error is still detected, since each portion will indicate an parity error, and a parity error for only one portion is sufficient to alarm PEC 98. Thereafter, all three errors are corrected by substituting the bit field (address tag) from the other directory, and so the present invention can allow correction of multiple bit errors.
In FIG. 4, the line designated "CPU Snoops" generally refers to operations from an interconnect on the CPU side of the cache, and could include a direct interconnect to the CPU or a direct interconnect to another snooping device, i.e., a higher-level cache (e.g., L1); "System Bus Snoops" generally refers to operations from an interconnect on the system bus side of the cache and could include a direct interconnect to the system bus or a direct interconnect to another snooping device, i.e., lower-level cache (e.g. L2). Accordingly, the invention is not limited to any particular level of the cache hierarchy or the overall depth thereof.
Although FIG. 4 depicts only redundant cache directories, redundant cache entry arrays (two) could similarly be used, with parity checkers instead of mainline ECC circuits, wherein an error in one cache entry array would result in the value being read from the corresponding cache line of the other cache entry array. Although this approach would require practically doubling the size of cache, it speeds up cache operation and, as technology allows cache sizes to grow smaller and smaller, the overall size of the cache may become less significant that its speed. Also, any such increase in cache size may be partially offset by reductions in size arising from use of the above-described repair mask.
Another advantage of the use of two directories in the cache is the ability to perform two read operations per cycle, that is, one read operation from the CPU snoop and one read operation from the system bus snoop in parallel. This feature significantly improves overall read access time from the CPU and system bus since, in prior art cache designs, only one read operation can be performed in any given cycle. In the present invention, both reads can be performed in a single clock cycle. The only potential disadvantage to the use of redundant directories is the required doubling of cache directory size. This size increase may be acceptable, however, given the improved performance associated with the ability to perform two snoop operations in one cycle. Moreover, the cache speed may increase further due to the removal of ECC circuits in the critical path which makes the read operations occur even faster.
Yet another advantage of providing a plurality of cache directories to independently respond to operations from a plurality of snooping devices is the elimination of arbitration logic to select between CPU and system bus snoops. Since arbitration logic is traditionally in the critical path, this improves access times, as well as generally lessening the complexity of the cache. Still another advantage of providing two directories relates to the physical layer--when a single directory is used, it requires longer access times for some cache lines which are physically spaced from the directory on the cache chip. For example, a single directory is often placed near the center of a chip to minimize such lengthened access times. By providing two directories, they may be physically spaced apart on the cache chip (i.e., near the sides instead of the center), allowing quicker response time by shortening conductive paths on the chip.
The dual read ability may also be provided with a single cache entry array or with two (redundant) cache entry arrays. In the latter case, two different multiplexers, separately controlled by two different control circuits respectively connected to the two directories 72 and 96, are used to read data from the two cache entry arrays. In the former case, two different multiplexers may still be used but they can be connected to the same cache entry array, i.e., each cache block has two output lines, one connected to a first multiplexer for the CPU snoop, and another connected to a second multiplexer for the system bus snoop.
When a memory block is written to the cache of FIG. 4, the address tag (and any miscellaneous bits such as the state and inclusivity fields) must be written to both directories 72 and 96. Write can be performed using one or more write queues 94 connected to directories 72 and 96. Writes to the two directories can happen in parallel; however, this requires that neither the CPU port nor the system bus port be executing a read, and so such parallel writes may take longer to drain from the write queues of the cache directories since there may be extended periods wherein, for every cycle, there is read operation being executed by one of the directories. Therefore, writes to the two directories may also be staggered, which is another advantage associated with the provision of multiple (redundant) cache directories.
In the latter implementation, for example, when the CPU is performing a read operation via directory 72, the system bus can be performing a write operation on directory 96 in the same cycle. The corresponding write operation to directory 72 can be put off (placed in a write queue) until the next or a subsequent cycle, when the CPU snoop is not performing any read (or other non-write) operation. Breaking up the write operation in this manner speeds up cache operation when redundant directories are used. If separate (redundant) cache entry arrays are used in conjunction with the two cache directories, then the operations of writing the memory block to the cache entry arrays may similarly be staggered.
This staggered writing also complements the ability to provide for separate reading from a directory. For example, consider the sequence wherein, during a first cycle, a read operation is occurring on directory 72 and a staggered write operation has just begun by first writing to directory 96; then, during a second cycle, the staggered write operation is completed by writing to directory 72, and a totally unrelated read occurs on directory 96. Thus, two read operations and one write operation were performed in two cycles. Although this effect might serendipitously be obtained without staggered writing (e.g., by having two read operations performed in a first cycle, followed by parallel writes to both directories in a second cycle), use of this feature imparts greater flexibility in execution of snoop operations which further improves performance.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment, as well as alternative embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined in the appended claims.
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A method of determining if a requested memory block of a memory device is contained in a cache used by a processor of a computer system is disclosed. An address associated with the requested memory block is compared to a plurality of address tags stored in a cache directory of the cache, while simultaneously performing error checks on the address tags. Corrected address tags are supplied for any erroneous address tags indicated by the error checks, and any corrected address tags are also compared to the address of the requested memory block. The error check may be a parity check of a portion of the address tag, either the entire portion, or of several subsets having a number of bits smaller than the address tag. The address tags can be stored in a redundant cache directory of the cache, and the corrected address tags supplied by substituting corresponding address tags from the redundant cache directory. By moving error checking out of the critical retrieval path of the cache, the present invention results in improved performance (increased speed).
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FIELD OF THE INVENTION
[0001] The present invention relates in general to fetal monitoring, and in particular to the automatic detection and analysis of fetal cardiac arrhythmias using body micro-vibrations.
BACKGROUND OF THE INVENTION
[0002] The position of a fetus within the womb, where it is surrounded by amniotic fluid, makes examination of the fetus very difficult for most examination techniques. Existing methods for monitoring, detecting and analyzing fetal heart rate problems have problems long acknowledged by the medical profession.
[0003] Traditional methods for measuring the fetal heart rate use ultrasound devices and various fetal monitors. All such methods are limited by the way the information is obtained and by the process of analyzing the results, and suffer from a number of common problems:
[0004] Intrusive—both an ultrasound and a fetal monitor require the mother to come to the testing facility and either have a monitor strapped on her abdomen (Fetal Monitor), or a conductive gel applied to the abdomen, followed by the use of a transducer (Ultrasound). Both solutions require special effort on part of the mother and use of major medical equipment.
[0005] Radiative—both ultrasound and fetal monitors transmit some sort of signal in order to obtain information about the fetus. In ultrasound, this is an ultrasonic pulse, transmitted directly toward the fetus through the conductive gel, whereas in a fetal monitor (such as the one used in a delivery room) the principle is much the same. In the sense that both solutions require transmission of a signal directly toward the fetus, the methods are “radiative”.
[0006] Invasive—for example, the fetal monitor in a delivery room requires an electrode to be an inserted into the mother to touch the head of the fetus.
[0007] The heart of the mother and the fetus are both organs with a mass of matter that moves and pushes fluids within their respective bodies, thereby generating internal vibrations within liquid media. The combined mother and fetus masses are represented by a body that has a “combined” center of gravity. The combined center of gravity moves in response to the movement caused by the pushing of fluids by the respective hearts to compensate accordingly, resulting in micro-vibrations that propagate through the mother's body. These micro-vibrations can advantageously be detected by a vibration sensor attached to the body.
[0008] Detection of body micro-vibration is known in the art, see for example R. Strum, R, B. Nigg and E. A. Koller, “The impact of cardiac activity on triaxially recorded endogenous micro-vibrations of the body”, European Journal of Applied Physiology, vol. 44, pp. 83-96, 1980. Strum et al. evaluated the relationship between the cardiac activity and the micro-vibrations of the body and concluded that the most important source of whole-body micro vibrations is the cardiac activity.
[0009] Active micro-vibration fetal heart monitoring is known, as disclosed for example in U.S. Pat. No. 6,454,716 and US Patent Applications Nos. 20030153831 and 20030153832 to Zumeris. The methods disclosed therein require an active element to generate vibrations or send a signal through the mother's body in order to detect parameters related to the fetal heartbeat.
[0010] Passive fetal monitoring that involves sensing of body vibrations is also known, as disclosed for example in U.S. Pat. No. 6,135,969 to Hale et al., US Patent Applications Nos. 20020068874 to Zuckerwar et al and 20030120159 to Mohler, and the references cited therein. Hale discloses a vibration sensor comprising a circular layer of piezoelectric material supported on a larger substrate disc of a thin, somewhat flexible material. Flexing of the disc generates an electrical signal. The substrate disc is weighted at its periphery, and the central portion of the disc is supported on a member for transferring motion or vibration that it is desired to detect. In the preferred embodiment the center support is provided by a pair of bosses projecting into the otherwise hollow interior of a two-part casing that encloses the disc-weight assembly. The weights impart a peripheral inertia that makes the composite unit sensitive to minute vibrations. Hale et al. does not indicate how the sensor may be used for FHR monitoring. Zuckerwar discloses a fetal heart monitoring system and method for detecting and processing acoustic fetal heart signals transmitted by different signal transmission modes. One signal transmission mode, the direct-contact mode, occurs in a first frequency band when the fetus is in direct contact with the maternal abdominal wall. Another signal transmission mode, the fluid propagation mode, occurs in a second frequency band when the fetus is in a recessed position with no direct contact with the maternal abdominal wall. The second frequency band is relatively higher than the first frequency band. The fetal heart monitoring system and method detect and process acoustic fetal heart signals that are in the first frequency band and in the second frequency band. Zuckerwar's system and method do not refer to directly, and are not concerned even indirectly with fetal heart induced micro-vibrations and their measurement. Mohler discloses an apparatus, operation and method for measurement of systemic and/or pulmonic blood pressure. The non-invasive measurement is done through detection, identification and characterization of the second heart sound acoustic signature associated with heart valve closure, through an acoustic sensor. Thus Mohler's system and method also do not refer to directly, and are not concerned even indirectly with fetal heart induced micro-vibrations and their measurement.
[0011] The mother's characteristics, in particular race, are known to affect the signals in fetal monitoring. For example, Johnson et al. in the American Journal of Obstetrics and Gynecology, vol. 17, pp. 779-783, 1998 have shown (Table II) that fetuses of black women have a much higher percent of beat-to-beat variability, variable decelerations and late decelerations than those of women of other ethnic origins. Yeo et al. in the Journal of Maternal-Fetal Investigation, vol. 16, pp. 163-167, 1996 have concluded that the mother's ethnic origin affects the FHR base line. However, none of the vibration-based fetal monitoring methods (either passive or active) take into account the mother's characteristics.
[0012] There is thus a widely recognized need for, and it would be highly advantageous to have, a micro-vibration based method and apparatus for fetal monitoring that takes into account the mother's characteristics and which provides continuous and automatic information about the fetal heart condition in a non-intrusive, non-invasive and non-radiating manner.
SUMMARY OF THE INVENTION
[0013] The present invention discloses a method and apparatus to automatically detect and analyze parameters related to the state of a fetal heart, specifically the existence of specific arrhythmias, in a non-invasive, non-intrusive and a non-radiating way, while accounting for maternal characteristics. The method is based on continuous monitoring of micro- or nano-vibrations (hereinafter “micro-vibrations”) that are transferred through the mother's body. These micro-vibrations are correlated with the fetal heart rate (FHR) and fetal movements, and relevant information regarding various fetal heart parameters is extracted from them using digital signal processing algorithms. The parameters may include FHR Base Line, FHR Acceleration, FHR Reactivity, FHR Silent Pattern, FHR Mild Deceleration, FHR Prolonged Deceleration, FHR Bradycardia, FHR Baseline Bradycardia, and FHR Baseline Tachycardia. While analyzing the fetal heartbeat pattern the present invention takes into account maternal characteristics such as the mother's race and the behavior of the maternal heartbeat signal.
[0014] The heart operation is cyclic. Both the mother and the fetus have a cyclic micro-movement frequency, which is almost constant over one heartbeat cycle. By using a plurality of micro-vibration sensors located at different positions relative to mother and fetus, we can relationally subtract the noises and filter out the required desirable signals. A sensor that is located closer to the mother's own heart would sense her heart in a stronger signal than a sensor that is located closer to the fetal heart. Although all sensors would sense the mother's heartbeat, by differentiating the signals received from other sensors, we identify the signals that are generated by the fetus. This is done by implementing commonly known mathematical algorithms for signal processing within the DSP element (as part of the signal filtering process).
[0015] According to the present invention there is provided a method for automatically detecting and analyzing heartbeat related arrhythmias of a fetus carried by a mother in a non-invasive, non-intrusive, non-radiating way comprising steps of passively sensing a plurality of micro-vibration signals transmitted through the mother's body, and extracting at least one fetal heart arrhythmia parameter from the micro-vibration signals, using maternal characteristics as an added input.
[0016] According to one aspect of the method of the present invention, the step of extracting includes extracting a parameter selected from the group consisting of a FHR (Fetal Heart Rate) Base Line parameter, a FHR Acceleration parameter, a FHR Silent Pattern parameter, a FHR Mild Deceleration parameter, a FHR Prolonged Deceleration parameter, a FHR Bradycardia parameter, FHR Baseline Bradycardia parameter and a FHR Baseline Tachycardia parameter.
[0017] According to another aspect of the method of the present invention, the step of sensing includes sensing the micro-vibration signals using at least two micro-vibration sensors disposed proximal to the mother's body.
[0018] According to yet another aspect of the method of the present invention, the sensing using at least two micro-vibration sensors includes sensing a signal that exhibits a difference in a micro-vibration parameter in each sensor, the micro-vibration parameter selected from the group consisting of a micro-vibration time lag, a micro-vibration amplitude and a combination thereof.
[0019] According to yet another aspect of the method of the present invention, the step of extracting includes obtaining a filtered fetal heart rate using the micro-vibration signals, and using the filtered fetal heart rate and the maternal characteristics as inputs to an extraction algorithm which outputs the at least one fetal heart arrhythmia parameter.
[0020] According to yet another aspect of the method of the present invention, the usage of the maternal characteristics includes using maternal race.
[0021] According to the present invention there is provided a method for automatically detecting and analyzing heartbeat related arrhythmias of a fetus carried by a mother, comprising the steps of passively sensing a plurality of micro-vibration signals transmitted through the mother's body; extracting fetal heart rate signals from the micro-vibration signals, providing maternal characteristics, and combining the fetal heart rate signals and the maternal characteristics to extract at least one fetal heart arrhythmia parameter.
[0022] According to one aspect of the method of the present invention, the step of passively sensing includes sensing the micro-vibration signals through at least two sensors, operative to receive each signal with a parameter difference.
[0023] According to another aspect of the method of the present invention, the parameter difference is selected from the group consisting of a time lag, a micro-vibration signal amplitude and a combination thereof.
[0024] According to another aspect of the method of the present invention, the step of providing maternal characteristics includes providing the maternal race.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Exemplary non-limiting embodiments of the invention are described in the following description, read with reference to the figures attached hereto. Dimensions of components and features shown in the figures are chosen primarily for convenience and clarity of presentation and are not necessarily to scale. The attached figures are:
[0026] FIG. 1 shows a flowchart of the main steps of the method of the present invention;
[0027] FIG. 2 represents a read-out of a fetal heart rate (FHR) signal with specific information;
[0028] FIG. 3 is an exemplary calculated beat spectrograph used to analyze and detect arrhythmias according to the present invention;
[0029] FIG. 4 is a representation of the input signal from the micro-vibrations sensors, showing example of a combined signal, an MHR signal and a FHR signal;
[0030] FIG. 5 is a representation of the filtering process, in which the noise and MHR are subtracted from the input signal to provide the filtered fetal heart rate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] FIG. 1 shows a schematic flow chart describing the main steps of the method of the present invention. In step 102 , analog micro-vibration signals are detected using at least one, and more preferably a plurality of sensors located in desired positions around the mother's body, preferably around her abdominal area. “Micro-vibration” in the present disclosure includes “nano-vibration” i.e. vibration processes on both nanometer and micrometer scale. The micro-vibration sensors sense the combined micro-vibration signals produced by the heart motions of both mother and fetus. Micro-vibration sensors applicable for the purposes of the present invention include for example the micro vibrations sensor described in U.S. Pat. No. 6,621,278. The micro-vibration signals are first converted from analog to digital so that they can be processed by a processing element in step 104 , for example a digital signal processing (DSP) element. The DSP element performs a signal filtration and noise reduction from the input signal as well as subtracts the mother's heartbeat signal from the information received by the sensors. The removal is based on the fact that the mother's heart rate cyclic frequency is constant and differs from the frequency of the fetus's heart rate. By applying conventional algorithms known in the art, one can subtract the mother's heartbeat signal and receive the fetus's heartbeat signal. An exemplary procedure for filtering maternal and fetal heartbeat signals may be found in U.S. Pat. No. 6,751,498. The filtered maternal and fetal heartbeat signals are then saved into a memory element. In step 106 , the information stored in the memory element is analyzed, and required heart parameters are extracted using calculations known in the art, for example as described by Van-Leeuwan et al. in BMC Physiology, volume 3, 2003, and Yeo et al., Journal of Maternal-Fetal Investigation, vol 16 (1996) pages 163-167. These calculations include calculating the base line (which is the common value in a 10 minute measurement) and detecting arrhythmias, which are variations from the base line on a time axis of between 20 and 40 minutes. Inventively, and in contrast with all prior art methods for extraction of fetal arrhythmia parameters, the present invention uses the maternal characteristics as an integral input in the extraction step. As mentioned, Yeo et al. have concluded that the mother's ethnic origin affects the FHR base line. By using the maternal ethnic origin as an added input, the base line value and any other measurements take into account the statistical information relating to the effects of the maternal ethnic origins on the FHR. Further inventively and in contrast with all prior art, the maternal characteristics so used are included in signals obtained with micro-vibration measurements. The extracted parameters may include FHR Base Line, FHR Acceleration, FHR Reactivity, FHR Silent Pattern, FHR Mild Deceleration, FHR Prolonged Deceleration, FHR Bradycardia, FHR Baseline Bradycardia, and FHR Baseline Tachycardia.
[0032] All the micro-vibration sensors located around the mother's body receive the same information, but with a difference of time and amplitude. For example, the signal sensed by at least one sensor (e.g. a sensor A) located in the mother abdomen area will differ from the same signal sensed by at least one other sensor (e.g. a sensor B) located near the mother's heart area in either time lag, amplitude or both. Exemplarily, a vibration sensed as “strong” by sensor A, and weaker and delayed by sensor B has probably originated near sensor A. If the “abdomen” sensor detects a heartbeat, and the same heartbeat is detected at a “chest” sensor, but with a delay and with lesser amplitude, this heartbeat is probably a fetal heartbeat. Conversely, if the heartbeat is detected (through the micro-vibration) first by the “chest” sensor, and detected later and weaker by the abdomen sensor, this heartbeat may be confidently attributed to the mother's heart. Noises that are detected by all sensors more or less at the same amplitude and time are considered to be external noises, not related to the heartbeats of the mother and fetus. Thus the method of the present invention can differentiate through micro-vibration measurements between the fetal heartbeat and the maternal heartbeat, and use signal filtering and processing to obtain the fetal arrhythmia parameters, while taking into consideration the maternal characteristics.
[0033] FIG. 2 displays an output of a fetal heart rate signal, where the Y Axis 202 represents the fetal heartbeat rate (FHR). A normal value for FHR is 120-160 beats per minute (BPM). A change 204 of up to 20 beats for a duration of up to 1 minute is also considered normal. The best known parameter upon which all arrhythmia detection algorithms depend upon is the “FHR base line” 206 , which is the most common FHR value during the previous 10 minutes. A minimum change 208 of FHR values from the last FHR base line values of up to 5 BPM should appear during 20% of the sampling time (see Williams Obstetrics, 21st edition; 2001 pages 334-337).
[0034] All arrhythmias are considered as FHR values variations from the base line over a defined duration of time. In order to detect the existence of arrhythmias, the sampling time frame should be between 20 and 40 minutes. The disclosed method simply follows the known rules of the art in order to detect and identify FHR related arrhythmias. However, in contrast with normal procedure, the maternal characteristics are used as an integral part (input) in this identification.
[0035] FIG. 3 displays a calculated beat spectrograph according to which known phenomena and syndromes are analyzed. The figure shows a three dimensional graph which represents the operational cycle of the heart (of the fetus), where the X, Y and Z axes represent the changes in the center of gravity, while the Z axis is also shifted in order to present those cycles over time and to allow counting and processing of intervening geometrical changes. Shifting the Z axis by time creates a geometrical “spiral like” graph, which represents changes in the center of gravity of the mother heart, fetus heart and other internal/external mass movements.
[0036] FIG. 4 shows a typical graph 402 (top) containing information received from one or more sensors. The information within graph 402 contains both the maternal and fetal heartbeat signals and includes additional noise. The mother heartbeat rate (MHR) signals 404 (middle graph) and FHR signals 406 (bottom graph) are derived from the top graph. MHR signals 404 have a frequency 408 and FHR signals 406 have a frequency 410 . When sensed with micro-vibration sensors, each peak in signals 406 may appear differently at different sensors. In particular, each peak may have a different shape (distortion) and amplitude, and the frequency 410 may vary also between the sensors. A time lag between identical peaks received at different sensors, depending on their location proximal to the mother's body, may also be measured. All these may be used as inputs to the extraction algorithms, in combination with the maternal characteristics.
[0037] FIG. 5 illustrates an example of the filtering process, where an input signal 502 is the combined signal of mother and fetal micro-vibrations and additional noise (similar to 402 in FIG. 4 ). The noise is removed, leaving only combined maternal and fetal heart signals 504 . The maternal and fetal waveforms are separated (signals 506 and 508 respectively) from the combined signal. The information contained in waveforms 508 , is combined with the input of maternal characteristics to advantageously provide the various fetal arrhythmia parameters.
[0038] All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent and patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.
[0039] The present invention has been described using non-limiting detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. It should be understood that features and/or steps described with respect to one embodiment may be used with other embodiments and that not all embodiments of the invention have all of the features and/or steps shown in a particular figure or described with respect to one of the embodiments. Variations of embodiments described will occur to persons of the art.
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A method to analyze the fetus's heartbeat signal and detect a specific list of FHR arrhythmias in a non-intrusive, non-invasive and non-emitting way. The method comprises passively sensing a plurality of micro-vibration signals transmitted through the mother's body; and extracting at least one fetal heart arrhythmia parameter from said micro-vibration signals, using maternal characteristics as an added input.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of co-pending application entitled “INTERCHANGEABLE TUNERS FOR A TAILPIECE OF A MUSICAL INSTRUMENT,” having Attorney Docket No. FRIR-0002, and U.S. patent application Ser. No. 13/104,147, filed on May 10, 2011, the entire contents of which are herein incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to a tailpiece of a musical instrument. Specifically, the present invention relates to a tailpiece for a musical instrument.
BACKGROUND OF THE INVENTION
[0003] Stringed instruments are well known throughout the musical world. As is generally know, a stringed instrument will typically include, among other parts, a body, neck, bridge, and a set of strings. In instruments such as violins, violas, cellos, etc., a tailpiece can also be included. The tailpiece is attached to the body and receives the strings, thus, holding the strings in a linear and tightened position. The traditional mechanism available to a player for adjusting the pitch of the strings involves turning the pegs of the instrument. Typically, a first end of each of four strings of the instrument is attached to (i.e., wound around) one of the four pegs in a pegbox. Each of the second ends of the four strings is inserted through and retained in a corresponding opening in the tailpiece. The pitch of a string, which is determined primarily by its tension and length, can be changed by turning the peg to which it is attached.
[0004] Players can also adjust the pitch of a string using a fine tuner attached to the second end of the string at its corresponding hole in the tailpiece. Typically, the end of the string to be fine-tuned is looped around a hook on the fine tuner, such that the turn of a thumbscrew on the fine tuner changes the length of the string and, therefore, its pitch. Most modern players use fine tuners because it makes tuning their instruments much easier and requires less time. Some players like them only on the higher pitch strings because those strings tend to go out of tune more often. However, current approaches fail to provide easy interchangeability/customization desired by many players.
SUMMARY OF THE INVENTION
[0005] In general, the present invention provides a tailpiece for a musical instrument. Among other things, the tailpiece includes: a treble side; a bass side opposite the treble side, wherein the treble side is longer than the bass side at a tip of the tailpiece such that the treble side extends further towards a bridge of the musical instrument along an axis oriented from a tail end of the tailpiece towards the tip of the tailpiece; and a plurality of string holes for holding a plurality of strings on the treble side and the bass side. In one embodiment, the tip of tailpiece has an S-shaped topography that causes the tailpiece to twist when the bass side is brought under tension. The tip of the tailpiece curves down towards the musical instrument to position the bass side closer to the musical instrument than the treble side.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings in which:
[0007] FIG. 1A depicts a top surface of a tailpiece according to one embodiment of the present invention.
[0008] FIG. 1B depicts a top surface of a tailpiece according to another embodiment of the present invention.
[0009] FIG. 2 depicts the tailpiece of the present invention on a musical instrument.
[0010] FIG. 3 depicts a perspective view of a tailpiece of the present invention with a plurality of openings according an embodiment of the invention.
[0011] FIG. 4A depicts a perspective view of a detachable tuner according to an embodiment of present invention.
[0012] FIG. 4B depicts a perspective view of a detachable keyhole string insert according to an embodiment of invention.
[0013] FIG. 5A depicts a perspective view of an apparatus including a set of detachable tuners and a set of detachable keyhole string inserts positioned within openings of the tailpiece according to an embodiment of the invention.
[0014] FIG. 5B depicts a bottom view of the apparatus of FIG. 5A according to an embodiment of the invention.
[0015] The drawings are not necessarily to scale. The drawings are merely schematic representations, not intended to portray specific parameters of the invention. The drawings are intended to depict only typical embodiments of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements.
DESCRIPTION OF THE INVENTION
[0016] Exemplary embodiments now will be described more fully herein with reference to the accompanying drawings, in which exemplary embodiments are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of this disclosure to those skilled in the art. In the description, details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the presented embodiments.
[0017] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, the use of the terms “a”, “an”, etc., do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. It will be further understood that the terms “comprises” and/or “comprising”, or “includes” and/or “including”, when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.
[0018] As indicated above, the present invention provides a tailpiece for a musical instrument. Among other things, the tailpiece includes a plurality of openings for receiving a plurality of strings and a detachable tuner positioned within one or more of the plurality of openings. Among other features, the tailpiece includes a set of detachable keyhole inserts positioned within one or more of the openings of the tailpiece unoccupied by a detachable tuner. Each detachable tuner is interchangeable with one of the detachable keyhole string inserts, thus allowing players to use tuners with any string desired for complete customization based on each player's preference.
[0019] Referring now to FIG. 1A , a top surface of a tailpiece 10 according to the present invention is shown. As depicted, tailpiece 10 includes a tail end 12 , a head 14 , a bass side 16 , a treble side 18 , and a plurality of string holes 20 A-N for receiving a plurality of strings (shown in FIG. 3 ). FIG. 1B shows a top surface of another tailpiece according to the present invention. Similarly, tailpiece 20 includes a tail end 22 , a head 24 , a bass side 26 , a treble side 28 , and a plurality of string holes 30 A-N for receiving a plurality of strings. Tailpiece 20 also includes tuning screw 32 and tuner 34 .
[0020] FIG. 2 depicts tailpiece 10 attached to a musical instrument 58 . As shown, string holes 20 A-N ( FIG. 1A ) receive strings 60 A-N. In this embodiment, tailpiece 10 is designed so that the open string length below a bridge 40 is progressively longer for each lower pitch string (e.g., 60 N). This feature provides more string area for the longer wavelength bass tones to resonate from the bass strings. In this configuration tailpiece 10 balances the instrument by adding clarity and strength to the bass tones to match the typically stronger projection and clarity produced from the treble strings (e.g., 60 A). The lengthening of the bass strings greatly reduced wolf tones (i.e., a dissonant sound that is often accompanied by an audible pulse) by changing the harmonics of the instrument. The sympathetic vibrations are still present, and very much needed to get the most projection and tonal richness from the instrument, but the unpleasant harmonics are reduced. Furthermore, tailpiece 10 has a built in twist due to its ‘S’ shaped head 14 in the tip area where the strings 60 A- 60 N attach. This configuration positions the bass strings (e.g., 60 N and 60 C) lower than the treble strings, which redistributes the down force on bridge 40 . This significantly increases the efficiency of bridge 40 and enhances the overall volume and projection of instrument 58 .
[0021] Referring now to FIG. 3 , a tailpiece 61 according to an embodiment of the invention will be described in greater detail. As shown, tailpiece 61 comprises a treble side 62 , a bass side 64 opposite treble side 62 , and a plurality of openings 66 A-N for receiving a set of detachable tuners and/or a set of detachable keyhole string attachments, as will be further discuss below. Openings 66 A-N receive a plurality of strings (not shown) during operation. Tailpiece 61 includes a tail end 68 and a head 70 .
[0022] Tailpiece 61 is configured to operate with a detachable tuner 80 and a detachable keyhole string attachment 95 depicted in FIGS. 4A and 4B , respectively. As shown, detachable tuner 80 (i.e., a fine tuner) comprises an opening 82 for receiving an instrument string (not shown), and a tuner arm 84 having a channel 86 at a first end for containing the instrument string. Tuner arm 84 operates with a tuning screw 88 at a second end for controlling the fine-tuning of the instrument strings by the player. During operation, detachable tuner 80 is attachable/detachable with tailpiece 61 and is situated within one or more openings 66 A-N shown in FIG. 3 . That is, an outside perimeter surface 90 of detachable tuner 80 is in abutment with an inner surface 65 of tailpiece 61 formed by at least one of the plurality of openings 66 A-N in tailpiece 61 ( FIG. 3 ). In one embodiment, outside perimeter 90 of detachable tuner 80 further comprises a set of fasteners 92 A, 92 B for coupling detachable tuner 80 to tailpiece 61 . However, it will be appreciated that fasteners 92 A, 92 B are shown for exemplary purposes only, and that many alternative configurations for securing the detachable tuners to the tailpiece are possible within the scope of the invention.
[0023] FIG. 4B depicts detachable keyhole string insert 95 according to an embodiment of the invention. As shown, detachable keyhole string insert 95 comprises an opening 96 for receiving the instrument string, and a lip 98 , which prevents the instrument string from resting flat against the front face of detachable keyhole string insert 95 . During operation, detachable keyhole string insert 95 is attachable/detachable with tailpiece 61 and is situated within one or more openings 66 A-N shown in FIG. 3 . That is, similar to tuner 80 , an outside perimeter surface 100 of detachable keyhole string insert 95 is in abutment with inner surface 65 of tailpiece 61 formed by at least one of the plurality of openings 66 A-N in tailpiece 61 ( FIG. 3 ). In an embodiment, outside perimeter 100 of each detachable keyhole string insert 95 includes a set of fasteners 102 A, 102 B for coupling detachable keyhole string insert 95 to tailpiece 61 .
[0024] The basic structure/geometry of detachable tuner 80 and detachable keyhole string insert 95 allows each component to be easily interchanged for one another, as shown in FIGS. 5A-5B . Apparatus 110 comprises tailpiece 61 having a set of detachable tuners 80 and a set of detachable keyhole string inserts 95 positioned within openings 66 A-N ( FIG. 3 ). As designed, each of the detachable tuners 80 is interchangeable with each of the detachable keyhole string inserts 95 . This allows increased customization by a player. For example, based on preference, players may wish to use detachable tuners 80 on some or all of the strings. If a player wishes to position tuners on less than all of the strings, detachable keyhole inserts 95 are used within any the openings unoccupied by detachable tuners 80 . The detachable tuners may be swapped with detachable keyhole string inserts, thus allowing players to use tuners with any string desired for complete customization based on each player's preference.
[0025] Furthermore, as discussed above, tailpiece 61 has a built in twist due to its ‘S’ shaped head 14 in the area where the strings 60 A- 60 N attach. That is, a tip portion 104 near treble side 64 of head 14 curves down towards musical instrument 58 ( FIG. 2 ) to position the bass strings (e.g., 60 N and 60 C) lower than the treble strings (e.g., 60 A-B). This redistributes the down force on bridge 40 , which significantly increases the efficiency of bridge 40 and enhances the overall volume and projection of instrument 58 .
[0026] The foregoing description of various aspects 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 form disclosed, and obviously, many modifications and variations are possible. Such modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of the invention as defined by the accompanying claims.
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In general, the present invention provides a tailpiece for a musical instrument. Among other things, the tailpiece includes: a treble side; a bass side opposite the treble side, wherein the treble side is longer than the bass side at a tip of the tailpiece such that the treble side extends further towards a bridge of the musical instrument along an axis oriented from a tail end of the tailpiece towards the tip of the tailpiece; and a plurality of string holes for holding a plurality of strings of the musical instrument.
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PRIORITY CLAIM
[0001] This application claims priority from U.S. Provisional Application Ser. No. 60/607,476, filed Sep. 3, 2004, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] Typical aircraft radar altimeters include separate reception and transmission antennas located on the bottom of the fuselage of commercial or private aircraft. Separate transmit and receive antennas have historically been used in order to provide isolation between the transmitter and receiver during continuous transmission and reception of a radar signal. Transmitter to receiver isolation was required due to technology shortcomings of microwave signal sources and microwave device packaging technology. Similarly, microwave sources used in present radar altimeters used open loop methods.
[0003] Operation of existing radar altimeters relies on a reflection of the transmitting antenna signal from the ground to the receiving antenna. At high altitudes, the separation distance between transmit and receive antennas results in a small reflection angle between the transmitted and received signals and provides excellent signal reception. At much lower altitudes, such as during a landing; the reflection angle between the transmitting and receiving antennas becomes very large, thus attenuating signal reception at the outer reaches of the antenna beamwidths. When the aircraft is below a low altitude threshold, the reflection angle will exceed the beamwidth of the transmitting or receiving antennas and altimeter operation will cease. Therefore, at low altitudes the separation distance between the two antennas of conventional radar altimeters reduces the received signal strength compromising signal-to-noise ratio and thus reduces altitude accuracy. Moreover, conventional dual antenna altimeters may erroneously acquire reflections from aircraft components such as engines and wheel gear instead of the correct ground reflection. When at low altitudes, a single antenna radar altimeter uses a single vertical reflection path to and from the ground not impacted by altitude or attitude of the aircraft. In special applications such as an aircraft tail-strike protection system, there is a requirement to measure distances to the ground of less than one foot. Hence, a dual antenna altimeter will not function in such applications. Therefore, there are many needs for a single antenna FM radar altimeter.
[0004] The U.S. Pat. No. 6,426,717 to Maloratski presents a single antenna FM radar altimeter that performs continuous wave (FM/CW) modulation as well as an interrupted continuous wave modulation. FIG. 1 illustrates Maloratski's radar altimeter and FIG. 2 illustrates phase noise produced by a comparable system. Maloratski includes a circulator that directs transmission signals to the antenna or directs received signals through a radar-processing portion. Maloratski connects the circulator to the antenna via a coax cable, as it is the intent of the patent to remotely locate the radio frequency generation components of the altimeter from the antenna. Precision low range altimeter applications require exceptionally stable altitude data. However, temperature and moisture may affect coax cables by increasing cable insertion loss, increasing reflection coefficients and changes in propagation delay times. Therefore, no means presently exist to continuously calibrate the true electrical length of the connecting cable. Any radar altimeter connected to its antenna or antennas via coax must calibrate propagation delay in order to determine a fixed distance to and from the transmitting and receiving antenna(s) caused by the electrical length of the coax for each aircraft installation.
[0005] Maloratski also presents closed-loop analog circuitry for continuously adjusting modulation rate to produce a constant frequency received signal but the loop does not control the linearity or phase noise of the radar modulation. Any frequency modulated radar altimeter relies upon a nearly ideal linear modulation function of frequency change versus time. Maloratski's closed-loop analog circuitry provides no means to verify that the modulation function is nearly ideally linear as a function of time, temperature or other environmental effects because it controls the frequency of the received signal only. In this way, Maloratski's approach uses an open loop modulation system.
[0006] Radio frequency sources of many types are subject to Frequency Pulling as a function of load impedance. As a result, open loop modulation systems suffer distortion in the linearity of the frequency modulation function due to a varying Voltage Standing Wave Ratio (VSWR) caused by coax cable deterioration and/or poor antenna matching. Poor modulation linearity results in degraded signal to noise ratio, altitude accuracy and causes errors in measurements of modulation rate.
[0007] Many conventional radar altimeters, including the single antenna altimeter proposed by Maloratski, continuously adjust the period of the linear frequency modulation waveform as a function of altitude in order to achieve a constant received difference frequency. This constant received difference frequency is key to the altitude tracking mechanism of Maloratski and most known radar altimeters. While this design feature provides a means to facilitate analog altitude tracking subsystems, it forces the altimeter to additionally provide an automatic gain control (AGC) circuit that adjusts the amplitude of the received signal as a function of altitude and reflection brightness from the ground. This design feature complicates the altimeter design and imposes limitations to the response time of the overall altimeter circuitry with rapidly varying ground heights.
[0008] A basic concern for Frequency Modulated/Continuous Wave (FM/CW) radars with a single antenna is a large signal reflection from its antenna or connecting coax. Large amplitude reflections from the antenna or connecting coax cause the continuously transmitting radar to jam itself, thereby limiting sensitivity. Maloratski and others have utilized specialized cancellation circuitry in an attempt to prevent FM/CW self-jamming.
[0009] Therefore, present single antenna radar altimeter systems, like Maloratski, are overly complex, utilize open loop modulation and are relatively imprecise because of time and temperature changes and degraded RF performance due to coax cable degradation over time.
[0010] Typically, all radar altimeters are located mid-ship on an aircraft in relatively close proximity to the antenna installations, in order to minimize coax losses at 4.3 GHz. Current radar altimeters have not been physically combined with any other navigation radio components. Consequently, the remotely located radar altimeter incurs a weight penalty because an extra box is needed and because many feet of heavy coax cable is used.
[0011] Therefore, there exists a need to reduce the weight of electronics on an aircraft while improving data analysis.
[0012] Multi-Mode Radio (MMR) systems have combined various navigation components, such as ILS, INS, GPS (GNSS), and other radios. Their use is limited to the data from one system backing up or verifying the data from another system. For example, when using INS data for an approach to landing, differentially corrected GPS data constantly corrects for INS data drift. If there is a loss of GPS data or GPS integrity falls below an acceptable value (due to satellite acquisition problems), INS data may only be used for short period.
[0013] Therefore, there exists a need to provide greater integrity of INS and GPS data for use in various navigation scenarios.
SUMMARY OF THE INVENTION
[0014] The present invention provides a system that physically combines the radar altimeter signal processing components with other navigation sensors while remotely locating the radio frequency portion at the antenna. The present invention combines flight safety critical sensors into a common platform to permit autonomous or semi-autonomous landing, enroute navigation and complex precision approaches in all weather conditions.
[0015] Inertial Navigation System (INS) circuitry that may include an inertial sensor, radar altimeter circuitry and Global Navigation Satellite System (GNSS) circuitry are housed in a single chassis. VHF (Very High Frequency) Omni-directional Radio (VOR), Marker Beacon (MB), MLS (Microwave Landing System), and VDB (VHF Data Broadcast) receiver circuitry may also be included in the chassis. Various technologies such as MEMS filters may permit dense packaging of all of these receiver functions onto as little as a single circuit board.
[0016] Weight and installation costs can be reduced by combining these functions into a single chassis with a single antenna radar altimeter. Other functions such as Doppler beam sharpening can occur because of the phase coherency of the modulated radar signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings.
[0018] FIG. 1 illustrates a block diagram of a prior art radar-altimeter system;
[0019] FIG. 2 illustrates phase noise produced by a prior art radar altimeter;
[0020] FIG. 3 illustrates a block diagram of a radar altimeter and tail strike warning system formed in accordance with an embodiment of the present invention;
[0021] FIG. 4 illustrates components of a transmitter included within the system shown in FIG. 3 ;
[0022] FIG. 5A illustrates detailed electronic components of a radar altimeter formed in accordance with an embodiment of the present invention;
[0023] FIG. 5B illustrates detailed electronic components of an alternate radar altimeter formed in accordance with an embodiment of the present invention;
[0024] FIG. 6 illustrates example phase noise produced by the radar altimeter formed in accordance with an embodiment of the present invention;
[0025] FIG. 7 illustrates a side view of a radar altimeter formed in accordance with an embodiment of the present invention;
[0026] FIG. 8 illustrates a block diagram of a navigation system formed in accordance with an embodiment of the present invention; and
[0027] FIG. 9 illustrates data analysis that can be produced by the system shown in FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
[0028] FIG. 3 illustrates an example system 30 that includes a radar altimeter 34 and a navigation radio unit 32 . The navigation radio unit 32 will be described in more detail below. The radar altimeter 34 produces a digital signal composed of frequencies that correspond to radar reflections at various altitudes. The produced digital signal is transmitted using an error detection/correction scheme to the navigation radio unit 32 over an Ethernet link, fiber optic cables, or another link that provides comparable high digital data bandwidth capabilities.
[0029] The radar altimeter 34 includes a single antenna 50 coupled to a circulator 52 . The circulator 52 is a conventional circulator commercially available to provide coupling of a transmitter 56 and a receiver 58 to the antenna 50 , while providing isolation between the transmitter 56 and the receiver 58 . The transmitter 56 is in signal communication with a Programmable Logic Device 66 . The receiver 58 is in communication with the A/D Converter 60 .
[0030] FIG. 4 illustrates components of the transmitter 56 . The transmitter 56 includes closed-loop circuit 70 , such as a phase-locked loop (PLL) circuit. In one embodiment, the circuit 70 includes a voltage-controlled oscillator (VCO) 90 that generates an output radar signal and a frequency divider 88 that scales the output of the VCO 90 from a microwave or millimeterwave frequency to a high VHF or UHF frequency. A phase/frequency comparator 84 compares the output of the frequency divider 88 with a reference signal generated by a direct digital synthesizer (DDS) 82 , a low pass filter (LPF) 78 , a band pass filter (BPF) 72 , a mixer 76 , and a frequency multiplier 74 and adjusts the output frequency of the VCO 90 such that it follows the frequency and phase of the digitally synthesized reference signal. The frequency multiplier 74 , mixer 76 and filters 72 and 78 are used to translate the linear frequency ramp of the DDS 82 up to UHF frequencies where it is compared directly with the UHF frequency output of the frequency divider 88 in a phase/frequency comparator 84 . A loop filter and amplifier 86 generates a tuning control signal for the VCO 90 based on the comparison done at the comparator 84 . The closed-loop modulation of the VCO 90 and amplifier 92 flows to the circulator 52 for output through the antenna 50 .
[0031] FIG. 5A illustrates a single antenna embodiment of the radar altimeter 34 ( FIG. 3 ). The transmitter 56 includes a first oscillator 100 for producing a clock signal. A frequency multiplication circuit 102 raises the clock signal frequency by a factor N such that it is sufficiently high to operate a direct digital synthesizer 104 and offset the output of the synthesizer 104 to the UHF band when the two are combined in a mixer 108 and filtered by bandpass filter 122 . The navigation radio unit 32 , located in the electronics bay, sends a control signal to a programmable logic device (PLD) 112 that converts the control signal into DDS commands that translate into a linear frequency modulation of a particular bandwidth and period or a calibration or self-test process. The DDS 104 generates a high quality linear FM ramp by generating precise and discrete sinusoidal amplitude samples at a rate of the clock frequency signal generated by the multiplication circuit 102 . The discrete sinusoidal amplitude samples that comprise the linear FM ramp produced by the DDS 104 pass through low pass filter (LPF) 120 where the output becomes a continuous analog signal at VHF frequencies. The continuous linear frequency modulation is added to the output of the frequency multiplication circuit 102 at mixer 108 . The output of the mixer 108 is band limited by band pass filter (BPF) 122 and becomes a UHF reference signal at the input of the phase and frequency comparator 84 ( FIG. 4 ) of the phase-locked loop (PLL) circuit 126 . The phase and frequency comparator 84 measures the instantaneous error between the frequency scaled input of frequency divider 88 and the linear frequency modulation output of the bandpass filter 122 . The output is applied to the voltage tuning input of the microwave or millimeterwave VCO 90 . In this manner, the instantaneous frequency of the VCO 90 follows the linear frequency modulation of DDS 104 . The internal DDS digital calculations and the timing provided by the multiplied clock frequency determine the DDS 104 output. Native non-linearities in the VCO tuning characteristics or those induced by external load conditions or external environment are automatically corrected by the measurements provided in the phase and frequency comparator 84 .
[0032] A receiver mixer 140 receives a small fraction of the output of the PLL 126 as the reference input of the mixer 140 in the receiver 58 . The mixer 140 subtracts the reference signal provided by the PLL 126 from the signal received by the antenna 50 via the circulator 52 . The frequency difference generated by the mixer 140 flows through a high pass filter (HPF) 142 , which filters the received analog signal and sends it to an analog to digital (A/D) converter 144 . The digital output of the A/D converter 144 arrives at an input of the navigation radio unit 32 . The navigation radio unit 32 computes Fast Fourier Transforms (FFT) of the sampled data. The resulting frequency bins of the FFT correspond to incremental altitude bins. Altitude frequency bins are evaluated to determine the aircraft height above the ground.
[0033] As shown in FIG. 5B , a transmission antenna 50 a and a reception antenna 50 b replace the single antenna 50 and circulator 52 as shown in FIG. 5A . This dual antenna configuration is useful where low transmitter power levels used in a single antenna system would limit the required maximum altitude range of the altimeter. In this case, the circulator 52 is removed and the required isolation between transmitter and receiver is achieved by separate transmit and receive antennas in a single hermetic package. In this embodiment, the invention continues to incorporate closed-loop digital synthesis of the linear frequency modulation, but measurement of very low altitudes are restricted to those ranges where the adjacent antenna beamwidths continue to overlap. The signal processing portion of the altimeter is located with the navigation system in a standard electronics bay, while the RF and antenna portion are optimally located on the aircraft to provide the most accurate information to the navigation system and flight controls.
[0034] In one specific embodiment of the transmitter 56 , the output of the transmitter 56 is a linear frequency sweep of 200 MHz modulated bandwidth between 4200-4400 MHz. In order to get this desired output, the navigation radio unit 32 instructs the DDS 104 via the PLD 112 to generate a signal having a bandwidth between 82.7-104.9 MHz. The frequency of clock oscillator 100 is 128 MHz and the multiplication factor of frequency multiplier 102 is three. Therefore, the output of the multiplication circuit 102 is 384 MHz and when combined at the mixer 108 produces a signal having a bandwidth between 466.7-488.9 MHz (having a center at 477 MHz) at the output of the BPF 122 . The PLL circuit 126 includes a voltage-controlled oscillator (VCO) 90 that can be tuned at least 300 MHz centered about 4300 MHz. Frequency divider 88 divides the VCO 90 generated 4300 MHz signal by a factor of 9 which results in an output frequency range of 466.7 MHz and 488.9 MHz when the tuning range of VCO 90 lies between 4200 MHz and 4400 MHz. Output of frequency divider 88 is compared to the output of bandpass filter 122 that contains the reference 466.7 to 488.9 MHz linear frequency sweep generated by the DDS 104 and the multiplied frequency output of frequency multiplier 102 . Any frequency or phase error between the reference signal and the frequency divided VCO signal is corrected by the error amplifier and filter by tuning the VCO 90 to achieve the correct frequency or phase within the PLL 126 .
[0035] The output radar signal produced by the transmitter 56 has a more definite defined range than prior art systems, thus providing greater differentiation of the center of the radar signal from side lobes. In addition, the outputted radar signal over time exhibits a more linear relationship between frequency and time due to less distortion. Also, as shown in FIG. 6 the phase noise is much lower than that produced by the prior art system of FIG. 2 . The substantially lower phase noise is critical because it is one of the primary reasons a single antenna radar altimeter is possible. Had the phase noise remained as high as encountered by the prior art altimeters, the radar would have been jammed by the excess noise and operation would not be possible. An exceptionally sensitive altimeter results when very low phase noise is combined with a controlled low Voltage Standing Wave Ratio (VSWR) at the antenna connection and exceptionally linear modulation. A single antenna altimeter is not possible without these attributes.
[0036] FIG. 7 illustrates a side view of a radar altimeter 200 packaged for use in an aircraft. The radar altimeter 200 includes a single micro-strip antenna 202 with a housing 204 attached to a back side of the antenna 202 . Included within the housing 204 are the circulator 52 (in a single transmit/receive antenna configuration), the transmitter 56 , and the receiver 58 . In one embodiment, the housing 204 is a welded cover that is sealed to the antenna 202 to form a hermetically sealed space within the housing 204 . Wires extending from the housing 204 pass through a waterproof connector 210 , thereby ensuring that the electronics within the housing 204 are protected from the environment.
[0037] Because the components of the radar altimeter 200 are attached directly to the antenna 202 , a coax cable connecting the circulator 52 to the micro-strip antenna 202 is not necessary. In this embodiment, the micro-strip antenna 202 is connected as closely as possible to a circuit board that includes the circulator 52 , the transmitter 56 , and the receiver 55 . In one embodiment, the distance between the circulator 52 (circuit board) and the micro-strip antenna 202 is approximately 0.1 inch. The present invention exhibits constant modulation quality and signal-to-noise ratio over time, thereby eliminating the need to recalibrate after installation or later. The modulated radar signal produced by the transmitter has a linearity error value of less than 0.05%.
[0038] In one embodiment, the circuit board and circuit components are a Silicon Gremanium (SiGe) Monolithic Microwave Integrated Circuit (MMIC). It can be appreciated that other configurations are possible.
[0039] If the radar altimeter 34 is not located at the tail of the aircraft, tail strike processing may include other information, such as pitch, or roll, received from other aircraft systems, such as the Flight Management System (FMS) or Flight Control System (FCS).
[0040] FIG. 8 illustrates the single antenna radar altimeter implemented with other navigation radio components into a single electronics bay or chassis 300 . The chassis 300 includes multiple circuit boards designated to perform different functions.
[0041] The chassis 300 is preferably located in an electronics bay of the aircraft. The chassis 300 includes a plurality of circuit board receiving slots. In one embodiment, the chassis slots receive a first circuit board 306 having an Instrument Landing System (ILS) receiver and associated circuitry, a second circuit board 308 having an Inertial Navigation System (INS) receiver and associated circuitry, a third circuit board 310 having a Global Positioning System (GPS) or Global Navigation Satellite System (GNSS) and associated circuitry, a fourth circuit board 304 having radar altimeter components, and a fifth circuit board 312 having controlling processor and input/output (I/O) circuitry. In another embodiment integrated circuit technologies such as MEMS filters may permit integration of multiple radio receiver functions onto a single circuit board, further reducing weight and cost. The chassis 300 includes a motherboard that provides a common bus system for signal and power distribution between the circuit boards and other aircraft systems. Other power and processing circuit boards may be included in the chassis 300 .
[0042] A main processing circuit board or the fourth circuit board 304 includes Multi-Mode Radio (MMR) processing circuitry. In one embodiment, the MMR processing circuitry includes a digital signal processor (DSP) with FFT or a Field Programmable Gate Array (FPGA). The fourth circuit board 304 is in signal communication with other components of the chassis 300 . The MMR processing circuitry receives serial data produced by the Analog to Digital (A/D) Converter 60 of the radar altimeter 34 . The MMR processing circuitry also include an altitude computation processor that receives altitude bin data. The altitude computation processor analyzes distance to ground values. In one embodiment the altitude computation processor generates a tail strike warning based on the analysis. The altitude computation processor determines an altimeter value by determining position of the digital signal.
[0043] Because of the data received at the receiver 58 and digitized, light weight wires versus coax cable are all that need to be connected between the radar altimeter 34 and the chassis 300 . The type of data digitized by the A/D Converter 60 may be processed to yield different results.
[0044] In one embodiment, Doppler beam sharpening is performed, see FIG. 9 , because the transmitter 56 provides phase stability. In other words, the DDS 82 or 104 provides chirp-to-chirp (pulse-to-pulse) modulation that is phase coherent. Doppler beam sharpening can be used to perform Terrain Contour Matching (TERCOM) when compared to an altitude database.
[0045] When measured height above ground is compared with a stored altitude reference map, a comparison of location computed by the radar altimeter is made against a position computed by the Inertial sensor and GNSS sensor. For example, when the INS is in a coast situation, the radar altimeter information is combined to correct for any deviations. Thus, the present invention can be used to improve the integrity of various flight scenarios, such as CAT II/III landings.
[0046] In alternate embodiments, the chassis 300 includes various other types of receiver circuit boards, such as a Marker Beacon (MB) receiver 324 , a VHF (Very High Frequency) Omni-directional Radio (VOR) receiver 322 , a Microwave Landing System (MLS) receiver 320 , a VDB (VHF Data Broadcast) receiver 326 and associated circuitry. A tail strike altimeter hardware and/or software may also be included within the chassis 300 for providing accurate tail altitude information when an antenna is located at the tail of the aircraft.
[0047] While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. For example, the configuration shown in FIG. 8 is an example of one configuration, however, other configurations may be used without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.
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A radar altimeter system with a closed-loop modulation for generating more accurate radar altimeter values. The present invention combines flight safety critical sensors into a common platform to permit autonomous or semi-autonomous landing, enroute navigation and complex precision approaches in all weather conditions. An Inertial Navigation System (INS) circuit board, a radar altimeter circuit board and a Global Navigation Satellite System (GNSS) circuit board are housed in a single chassis. VHF (Very High Frequency) Omni-directional Radio (VOR), Marker Beacon (MB), and VDB (VHF Data Broadcast) receiver circuit boards may also be implemented on circuit boards in the chassis.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. application Ser. No. 13/064,987, filed Apr. 29, 2011, which was a continuation of U.S. application Ser. No. 12/801,952, filed Jul. 2, 2010, which was a continuation of U.S. application Ser. No. 12/659,980, filed Mar. 26, 2010, which issued as U.S. Pat. No. 7,797,970, which was a divisional of U.S. application Ser. No. 11/806,245, filed May 30, 2007, which issued as U.S. Pat. No. 7,743,633, which in turn claims the benefit of Korean Patent Application Nos. 2006-49501 and 2006-49482, both filed on Jun. 1, 2006, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] The present invention relates generally to a washing machine having at least one balancer, and more particularly to a washing machine having at least one balancer that increases durability by reinforcing strength and that is installed on a rotating tub in a convenient way.
[0004] 2. Description of the Related Art
[0005] In general, washing machines do the laundry by spinning a spin tub containing the laundry by driving the spin tub with a driving motor. In a washing process, the spin tub is spun forward and backward at a low speed. In a dehydrating process, the spin tub is spun in one direction at a high speed.
[0006] When the spin tub is spun at a high speed in the dehydrating process, if the laundry leans to one side without uniform distribution in the spin tub or if the laundry leans to one side by an abrupt acceleration of the spin tub in the early stage of the dehydrating process, the spin tub undergoes a misalignment between the center of gravity and the center of rotation, which thus causes noise and vibration. The repetition of this phenomenon causes parts, such as a spin tub and its rotating shaft, a driving motor, etc., to break or to undergo a reduced life span.
[0007] Particularly, a drum type washing machine has a structure in which the spin tub containing laundry is horizontally disposed, and when the spin tub is spun at a high speed when the laundry is collected on the bottom of the spin tub by gravity in the dehydrating process, the spin tub undergoes a misalignment between the center of gravity and the center of rotation, thus resulting in a high possibility of causing excess noise and vibration.
[0008] Thus, the drum type washing machine is typically provided with at least one balancer for maintaining a dynamic balance of the spin tub. A balancer may also be applied to an upright type washing machine in which the spin tub is vertically installed.
[0009] An example of a washing machine having ball balancers is disclosed in Korean Patent Publication No. 1999-0038279. The ball balancers of a conventional washing machine include racers installed on the top and the bottom of a spin tub in order to maintain a dynamic balance when the spin tub is spun at a high speed, and steel balls and viscous oil are disposed within the racers to freely move in the racers.
[0010] Thus, when the spin tub is spun without maintaining a dynamic balance due to an unbalanced eccentric structure of the spin tub itself and lopsided distribution of the laundry in the spin tub, the steel balls compensate for this imbalance, and thus the spin tub can maintain the dynamic balance.
[0011] However, the ball balancers of the conventional washing machine have a structure in which upper and lower plates formed of plastic by injection molding are fused to each other, and a plurality of steel balls are disposed between the fused plates to make a circular motion, so that the ball balancers are continuously supplied with centrifugal force that is generated when the steel balls make a circular motion, and thus are deformed at walls thereof, which reduces the life span of the balancer.
[0012] Further, the ball balancers of the conventional washing machine do not have a means for guiding the ball balancers to be installed on the spin tub in place, so that it takes time to assemble the balancers to the spin tub.
[0013] In addition, the ball balancers of the conventional washing machine have a structure in which a racer includes upper and lower plates fused to each other, so that fusion scraps generated during fusion fall down both inwardly and outwardly of the racer. The fusion scraps that fall down inwardly of the racer prevent motion of the balls in the racer, and simultaneously result in generating vibration and noise.
SUMMARY
[0014] Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a washing machine having at least one balancer that increases durability by reinforcing the strength of the balancer, which is installed on a rotating tub in a rapid and convenient way.
[0015] Another object of the present invention is to provide a washing machine having at least one balancer, in which fusion scraps generated by fusion of the balancer are prevented from falling down inward and outward of the balancer.
[0016] Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.
[0017] In order to accomplish these objects, according to an aspect of the present invention, there is provided a washing machine having a spin tub to hold laundry to be washed and at least one balancer. The balancer includes first and second housings, the first housing having at least one support for reinforcing a strength of the balancer. The first and second housings have an annular shape and are fused together to form a closed internal space.
[0018] Here, the first housing may have the cross section of an approximately “C” shape, and the support protrudes outwardly from at least one of opposite walls of the first housing.
[0019] Further, the spin tub may include at least one annular recess corresponding to the balancer such that the balancer is able to be coupled to the spin tub by being fitted within the recess.
[0020] Further, the support may protrude from the first housing and comes into contact with a wall of the recess, and guides the balancer to be maintained in the recess in place.
[0021] Also, the supports may be continuously formed along and perpendicular to the opposite walls of the first housing.
[0022] Further, the supports may be disposed parallel to the opposite walls of the first housing at regular intervals.
[0023] Meanwhile, the washing machine may be a drum type washing machine. A front member may be attached to a front end of the spin tub and a rear member may be attached to a rear end of the spin tub. The recesses may be provided at the front and rear members of the spin tub, and the balancers may be coupled to opposite ends of the spin tub at the recesses of the front and rear members.
[0024] The foregoing and/or other aspects of the present invention can be achieved by providing a washing machine having at least one balancer. The balancer includes a first housing and a second housing fused to the first housing, and the first and second housings are fused together to form at least one pocket between the first housing and the second housing, the pocket capable of collecting fusion scraps generated during fusion.
[0025] Here, the first housing may include protruding fusion ridges protruding from ends of the first housing, and the second housing may include fusion grooves receiving the fusion ridges of the first housing when the first housing and the second housing are fused together.
[0026] Further, the first housing may further include inner pocket ridges protruding from the first housing and spaced inwardly apart with respect to the fusion ridges of the first housing.
[0027] Further, the second housing may further include outer pocket flanges protruding from the second housing and being situated on outer sides of the fusion grooves when the first housing is fused together with the second housing so the outer pocket flanges are spaced apart from the fusion ridges of the first housing by a predetermined distance, causing an outer pocket to be formed between the fusion ridges and the outer pocket flanges.
[0028] Further, the second housing may include guide ridges protruding from the second housing and protruding toward the first housing to closely contact the inner pocket ridges of the first housing when the first and second housings are fused together.
[0029] Also, the balancer may further include a plurality of balls disposed within an internal space formed by fusing the first and second housings together, the balls performing a balancing function.
[0030] In addition, the washing machine may further include a spin tub disposed horizontally, and the balancers may be installed at front and rear ends of the spin tub.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The above and other aspects, features and advantages of the present invention will be more apparent from the following detailed description of the embodiments, taken in conjunction with the accompanying drawings, in which
[0032] FIG. 1 is a sectional view illustrating a schematic structure of a washing machine according to the present invention;
[0033] FIG. 2 is a perspective view illustrating balancers according to the present invention, in which the balancers are disassembled from a spin tub;
[0034] FIG. 3 is a perspective view illustrating a balancer according to a first embodiment of the present invention;
[0035] FIG. 4 is an enlarged view illustrating section A of FIG. 1 in order to show the sectional structure of a balancer according to a first embodiment of the present invention;
[0036] FIG. 5 is a perspective view illustrating a balancer according to a second embodiment of the present invention;
[0037] FIG. 6 is an enlarged view illustrating the sectional structure of a balancer according to the second embodiment of the present invention;
[0038] FIG. 7 is a perspective view illustrating a disassembled balancer according to a third embodiment of the present invention;
[0039] FIG. 8 is a perspective view illustrating an assembled balancer according to the third embodiment of the present invention;
[0040] FIG. 9 is a partially enlarged view of FIG. 7 ; and
[0041] FIG. 10 is a sectional view taken line A-A of FIG. 8 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0042] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.
[0043] Hereinafter, exemplary embodiments of the present invention will be described with reference to the attached drawings.
[0044] FIG. 1 is a sectional view illustrating the schematic structure of a washing machine according to the present invention.
[0045] As illustrated in FIG. 1 , a washing machine according to the present invention includes a housing 1 forming an external structure of the washing machine, a water reservoir 2 installed in the housing 1 and containing washing water, a spin tub 10 disposed rotatably in the water reservoir 2 which allows laundry to be placed in and washed therein, and a door 4 hinged to an open front of the housing 1 .
[0046] The water reservoir 2 has a feed pipe 5 and a detergent feeder 6 both disposed above the water reservoir 2 in order to supply washing water and detergent to the water reservoir 2 , and a drain pipe 7 installed therebelow in order to drain the washing water contained in the water reservoir 2 to the outside of the housing 1 when the laundry is completely done.
[0047] The spin tub 10 has a rotating shaft 8 disposed at the rear thereof so as to extend through the rear of the water reservoir 2 , and a driving motor 9 , with which the rotating shaft 8 is coupled, installed on a rear outer side thereof. Therefore, when the driving motor 9 is driven, the rotating shaft 8 is rotated together with the spin tub 10 .
[0048] The spin tub 10 is provided with a plurality of dehydrating holes 10 a at a periphery thereof so as to allow the water contained in the water reservoir 2 to flow into the spin tub 10 together with the detergent to wash the laundry in a washing cycle, and to allow the water to be drained to the outside of the housing 1 through a drain pipe 7 in a dehydrating cycle.
[0049] The spin tub 10 has a plurality of lifters 10 b disposed longitudinally therein. Thereby, as the spin tub 10 rotates at a low speed in the washing cycle, the laundry submerged in the water is raised up from the bottom of the spin tub 10 and then is lowered to the bottom of the spin tub 10 , so that the laundry can be effectively washed.
[0050] Thus, in the washing cycle, the rotating shaft 8 alternately rotates forward and backward by of the driving of the driving motor 9 to spin the spin tub 10 at a low speed, so that the laundry is washed. In the dehydrating cycle, the rotating shaft 8 rotates in one direction to spin the spin tub 10 at a high speed, so that the laundry is dehydrated.
[0051] When spun at a high speed in the dehydrating process, the spin tub 10 itself may undergo misalignment between the center of gravity and the center of rotation, or the laundry may lean to one side without uniform distribution in the spin tub 10 . In this case, the spin tub 10 does not maintain a dynamic balance.
[0052] In order to prevent this dynamic imbalance to allow the spin tub 10 to be spun at a high speed with the center of gravity and the center of rotation thereof matched with each other, the spin tub 10 is provided with balancers 20 or 30 according to a first or a second embodiment of the present invention (wherein only the balancer 20 according to a first embodiment is shown in FIGS. 1-4 ) at front and rear ends thereof. The structure of the balancers 20 and 30 according to the first and second embodiments of the present invention will be described with reference to FIGS. 2 through 6 .
[0053] FIG. 2 is a perspective view illustrating balancers according to the present invention, in which the balancers are disassembled from a spin tub.
[0054] As illustrated in FIG. 2 , the spin tub 10 includes a cylindrical body 11 that has open front and rear parts and is provided with the dehydrating holes 10 a and lifters 10 b , a front member 12 that is coupled to the open front part of the body 11 and is provided with an opening 14 permitting the laundry to be placed within or removed from the body 11 , and a rear member 13 that is coupled to the open rear part of the body 11 and with the rotating shaft 8 (see FIG. 1 ) for spinning the spin tub 10 .
[0055] The front member 12 is provided, at an edge thereof, with an annular recess 15 that has the cross section of an approximately “C” shape and is open to the front of the front member 12 in order to hold any one of the balancers 20 . Similarly, the rear member 13 is provided, at an edge thereof, with an annular, recess 15 (not shown) that is open to the rear of the front member 12 in order to hold the other of the balancers 20 .
[0056] The front and rear members 12 and 13 are fitted into and coupled to the front or rear edges of the body 11 in a screwed fashion or in any other fashion that allows the front and rear members 12 and 13 to be maintained to the body 11 of the spin tub 10 .
[0057] The balancers 20 , which are installed in the recesses 15 of the front and rear members 12 and 13 , have an annular shape and are filled therein with a plurality of metal balls 21 performing a balancing function and a viscous fluid (not shown) capable of adjusting a speed of motion of the balls 21 .
[0058] Now, the structure of the balancers 20 and 30 according to the first and second embodiments of the present invention will be described with reference to FIGS. 3 through 6 .
[0059] FIG. 3 is a perspective view illustrating a balancer according to a first embodiment of the present invention, and FIG. 4 is an enlarged view illustrating part A of FIG. 1 in order to show the sectional structure of a balancer according to a first embodiment of the present invention.
[0060] As illustrated in FIGS. 3 and 4 , a balancer 20 according to a first embodiment of the present invention has an annular shape and includes first and second housings 22 and 23 that are fused to define a closed internal space 20 a.
[0061] The first housing 22 has first and second walls 22 a and 22 b facing each other, and a third wall 22 c connecting ends of the first and second walls 22 a and 22 b , and thus has a cross section of an approximately “C” shape. The second housing 23 has opposite edges that protrude toward the first housing 22 and that are coupled to corresponding opposite ends 22 d of the first housing 22 by heat fusion.
[0062] The opposite ends 22 d of the first housing 22 protrude outward from the first and second walls 22 a and 22 b of the first housing 22 , and the edges of the second housing 23 are sized to cover the ends 22 d of the first housing 22 .
[0063] Thus, when the balancer 20 is fitted into the recess 15 of the front member 12 of the spin tub 10 , the first and second walls 22 a and 22 b are spaced apart from a wall of the recess 15 because of the ends and edges of the first and second housings 22 and 23 which protrude outward from the first and second walls 22 a and 22 b . Further, because the first and second walls 22 a and 22 b are relatively thin, the first and second walls 22 a and 22 b are raised outward when centrifugal force is applied thereto by the plurality of balls 21 that move in the internal space 20 a of the balancer 20 in order to perform the balancing function.
[0064] In this manner, the plurality of balls 21 make a circular motion in the balancer 20 , so that the first and second walls 22 a and 22 b are deformed by the centrifugal force applied to the first and second walls 22 a and 22 b of the first housing 22 . In order to prevent this deformation, the second housing 22 is provided with supports 24 according to a first embodiment of the present invention.
[0065] The supports 24 protrude from and perpendicular to the first and second walls 22 a and 22 b of the first housing 22 which are opposite each other, and may be continued along an outer surface of the first housing 22 , thereby having an overall annular shape.
[0066] The supports 24 have a length such that they extend from the first housing 22 to contact the wall of the recess 15 . Hence, the first and second walls 22 a and 22 b are further increased in strength, and additionally function to guide the balancer 20 so as to be maintained in the recess 15 in place.
[0067] Here, when the plurality of balls 21 make a circular motion in the first housing 22 , the centrifugal force acts in the direction moving away from the center of rotation of the spin tub 10 . Hence, the centrifugal force acts on the first wall 22 a to a stronger level when viewed in FIG. 4 . Thus, the supports 24 may be formed only on the first wall 22 a.
[0068] In the balancer 20 according to the first embodiment of the present invention, when the first and second housings 22 and 23 are fused together and fitted into the recess 15 of the spin tub 10 , the supports 24 are maintained in place while positioned along the wall of the recess 15 . Finally, the balancer 20 is coupled and fixed to the front member 12 of the spin tub 10 by screws (not shown) or in any other fashion that allows the balancer 20 to be coupled to the front member 12 .
[0069] Although not illustrated in detail, the balancer 20 is similarly installed on the rear member 13 of the spin tub 10 .
[0070] The ends 22 d of the first housing 22 include fusion ridges 42 a that protrude toward the second housing 23 . The fusion ridges 42 a are inserted within fusion grooves 43 a of the second housing 23 .
[0071] FIGS. 5 and 6 correspond to FIGS. 3 and 4 , and illustrate a balancer 30 according to a second embodiment of the present invention.
[0072] The balancer 30 according to the second embodiment of the present invention has an annular shape and includes first and second housings 32 and 33 that are fused together forming an internal space 30 a therebetween in which a plurality of balls 31 are disposed. The balancer 30 according to the second embodiment of the present invention is similar to that of balancer 20 according to the first embodiment of the present invention, except the structure of supports 34 of balancer 30 is different from that of the structure of the supports 24 of balancer 20 .
[0073] As illustrated in FIGS. 5 and 6 , the supports 34 according to the second embodiment of the present invention protrude parallel to first and second walls 32 a and 32 b of a first housing 32 which are opposite each other, and the supports 34 are disposed at regular intervals along the first and second walls 32 a and 32 b . The first housing 32 further includes a third wall 32 c . Ends 22 d of the first housing 32 extend from an end of the first and second walls 32 a and 32 b.
[0074] Similar to the supports 24 according to the first embodiment, the supports 34 of the second embodiment have a length such that the supports 34 extend from the first housing 32 to contact the wall of the recess 15 . The surfaces of the supports 34 thereby abut portions of the front member 12 . Hence, the first and second walls 32 a and 32 b are further increased in strength, and additionally function to guide the balancer 30 so as to be maintained in the recess 15 in place.
[0075] Next, the construction of a balancer 40 according to a third embodiment of the present invention will be described with reference to FIGS. 7 through 10 .
[0076] FIGS. 7 and 8 are perspective views illustrating disassembled and assembled balancers according to the third embodiment of the present invention, FIG. 9 is a partially enlarged view of FIG. 7 , and FIG. 10 is a sectional view taken along line A-A of FIG. 8 .
[0077] As illustrated in FIGS. 7 and 8 , a balancer 40 includes a first housing 42 having an annular shape and a second housing 43 having an annular shape that is fused to the first housing 42 , thereby forming an annular housing corresponding to the recess 15 (see FIG. 2 ) of the spin tub 10 . The first and second housings 42 and 43 may be, for example, formed of synthetic resin, such as plastic by injection molding.
[0078] As illustrated in FIG. 9 , the first housing 42 has a cross section of an approximately “C” shape, includes fusion ridges 42 a protruding to the second housing 43 at opposite ends thereof which are coupled with the second housing 43 , and inner pocket ridges 42 b protruding to the second housing 43 spaced inwardly apart from the fusion ridges 42 a.
[0079] The second housing 43 , which is coupled to opposite ends of the first housing 42 in order to form a closed internal space 40 a for holding a plurality of balls 41 and a viscous fluid, includes fusion grooves 43 a recessed along edges thereof so as to correspond to the fusion ridges 42 a , outer pocket flanges 43 b and guide ridges 43 c . The outer pocket flanges protrude to the first housing 42 on outer sides of the fusion grooves 43 a so as to be spaced apart from the fusion ridges 42 a of the first housing 42 by a predetermined distance. The guide ridges 43 c protrude to the first housing 42 on inner sides of the fusion grooves 43 a and closely contact the inner pocket ridges 42 b of the first housing 42 .
[0080] The guide ridges 43 c of the second housing 43 move in contact with the inner pocket ridges 42 b of the first housing 42 when the second housing 43 is fitted into the first housing 42 , to thereby guide the fusion ridges 42 a of the first housing 42 to be fitted into the fusion grooves 43 a of the second housing 43 rapidly and precisely.
[0081] Thus, when the fusion ridges 42 a of the first housing 42 are fitted into the fusion grooves 43 a of the second housing 43 in order to fuse the first housing 42 with the second housing 43 , as shown in FIG. 10 , an inner pocket 40 b having a predetermined spacing is formed between the fusion ridges 42 a and inner pocket ridges 42 b , and an outer pocket 40 c having a predetermined spacing is formed between the fusion ridges 42 a and the outer pocket flanges 43 b.
[0082] In this state, when heat is generated between the fusion ridges 42 a of the first housing 42 and the fusion grooves 43 a of the second housing 43 , the fusion ridges 42 a and the fusion grooves 43 a are firmly fused with each other. At fusion, fusion scraps that are generated by heat and fall down inward of the first housing 42 are collected in the inner pocket 40 b , so that the scraps are not introduced into the internal space 40 a of the balancer 40 in which the balls 41 move. Fusion scraps falling down outward of the first housing 42 are collected in the outer pocket 40 c , and thus are prevented from falling down outward of the balancer 40 .
[0083] In the embodiments, the balancers 20 , 30 and 40 have been described to be installed on a drum type washing machine by way of example, but it is apparent that the balancers can be applied to an upright type washing machine having a structure in which a spin tub is vertically installed.
[0084] As described above in detail, the washing machine according to the embodiments of the present invention has a high-strength structure in which at least one balancer is provided with at least one support protruding outward from the wall thereof, so that, although the strong centrifugal force acts on the wall of the balancer due to a plurality of balls making a circular motion in the balancer, the wall of the balancer is not deformed. Thus, the plurality of balls can make a smooth circular motion without causing excess vibration and noise, and thus increasing the durability and life span of the balancer.
[0085] Further, the washing machine according to the embodiments of the present invention has a structure in which the balancer can be rapidly and exactly positioned in the recess of the spin tub by the supports, so that an assembly time of the balance can be reduced.
[0086] In addition, the washing machine according to the present invention has a structure in which fusion scraps generated when the balancer is fused are collected in a plurality of pockets, and thus are prevented from falling down inward and outward of the balancer, so that the internal space of the balancer, in which a plurality of balls are filled and move in a circular motion, has a smooth surface without the addition of fusion scraps. As a result, the balls are able to move more smoothly, and excess noise and vibration are minimized. The balancer may have a clear outer surface to provide a fine appearance without the fusion scraps, so that it can be exactly coupled to the spin tub without obstruction caused by the fusion scraps.
[0087] Although a few embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims and their equivalents.
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A drum type washing machine including a housing, a spin tub, and a ball balancer coupled to the spin tub, the ball balancer including a first plastic member and a second plastic member joined to each other to form an annular-shaped race, the first plastic member including a first side wall, a second side wall and a connecting wall to form a three-sided annular-shaped structure having an open side, and the second plastic member adapted to cover the open side, the three-sided annular-shaped structure having a U-shaped cross-section with a first rounded inside corner formed between the first side wall and the connecting wall and a second rounded inside corner formed between the second side wall and the connecting wall. A radius of curvature of each of the first and second rounded inside corners is greater than a radius of curvature of opposite diagonal inside corners of the annular-shaped race.
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BACKGROUND OF THE INVENTION
This invention relates to an improved hydrocarbyl-substituted succininc anhydride/nonionic emulsifier composition. This invention also relates to an improved method for imparting water repellency to surfaces containing groups reactive to anhydrides. A further aspect of this invention relates to an improved method for the sizing of paper and paperboard products.
It is well known in the art that hydrocarbyl-substituted succinic anhydrides are good for treating paper, fabric, or other surfaces to impart water repellency. As indicated in U.S. Pat. Nos. 3,102,064, 3,821,069, 3,968,005, and 4,040,900 (RE 29,960), these compositions are particularly useful for sizing paper.
It is also known that these succinic anhydrides are best applied for such purposes in a highly dispersed form, such as an aqueous emulsion. See, for example, U.S. Pat. No. 4,040,900 (RE 29,960), which describes paper sizing emulsions made from mixtures comprising a substituted cyclic dicarboxylic acid anhydride and polyoxyalkylene alkyl or alkylaryl ether or the corresponding mono- or di-ester.
Diester emulsifiers, as well as monoesters, alkyl phenol ethoxylates and alcohol ethoxylates, are disclosed in U.S. Pat. No. 4,040,900 (RE 29,960) as useful emulsifiers for substituted succinic anhydrides. This patent teaches that the polyoxyalkylene portion of the emulsifier must contain between 5 and 20 polyoxyalkylene groups. For polyoxyethylene (polyethylene glycol) type emulsifiers, this corresponds to a molecular weight range of about 238 to 899.
A major drawback of these prior art emulsifiers is the fact that, once formed, the succinic anhydride-emulsifier mixtures are unstable and must be promptly used. There therefore exists a need in the art for substituted succinic anhydride-emulsifier mixtures which demonstrate enhanced stability upon aging or storage.
SUMMARY OF THE INVENTION
The present invention provides a stable hydrocarbyl-substituted succinic anydride/nonionic emulsifier composition comprising:
(A) 70 to 99.5% of a normally liquid hydrocarbyl-substituted succinic anhydride containing from 6 to 50 carbon atoms in the substituent; and
(B) 0.5 to 30% of a polyethylene glycol diester emulsifier derived from a polyethylene glycol containing from 21 to 150 ethylene oxide units and a monocarboxylic acid containing from 8 to 25 carbon atoms.
The present invention further provides a method of imparting water repellency to surfaces containing groups reactive to anhydrides which comprises impregnating said surfaces with an aqueous emulsion of the substituted succinic anhydride/nonionic emulsifier composition of the invention.
The present invention is also concerned with a method of sizing paper which comprises intimately dispersing within the wet paper pulp, prior to the ultimate conversion of said pulp into a dry web, an aqueous emulsion of the substituted succinic anhydride/nonionic emulsifier composition of the invention.
Among other factors, the present invention is based on my discovery that polyethylene glycol diesters wherein the molecular weight of the polyethylene glycol is about 1000 or above are surprisingly effective emulsifiers on aging in substituted succinic anhydride. By comparison, commercially available diester emulsifiers wherein the molecular weight of the polyethylene glycol moiety is below about 1000 behave poorly or ineffectively on aging in substituted succinic anhydride.
DETAILED DESCRIPTION OF THE INVENTION
The substituted succinic anhydride useful for this invention is a hydrophobic molecule. Usually it will have one substituent in the 3-position but it may have substituents in both the 3- and 4-positions. In general, the substituent will be an alkyl, alkenyl or aralkyl group. Other elements may be present in a minor amount, such as a sulfur or ether linkage. The total number of carbon atoms in the substituent is between 6 and 50. A preferred substituent size is between 10 and 30 carbon atoms. More preferred is between 12 and 25 carbon atoms. A preferred embodiment of the contemplated anydrides is the alkenyl succinic anhydride made by allowing an olefin to react with maleic anhydride. For present purposes, I shall refer to the anhydrides contemplated as "ASA".
The emulsifier useful for the composition of the present invention is a polyethylene glycol diester derived from polyethylene glycol and a monocarboxylic acid. For purposes of the present invention, the polyethylene glycol will contain from 21 to 150 ethylene oxide units, preferably from about 22 to 90 ethylene oxide units. The molecular weight of the polyethylene glycol will be in the range of about 1000 to 6600, preferably in the range of about 1000 to 4000.
The monocarboxylic acids suitable for use in providing the polyethylene glycol diesters are organic acids containing from 8 to 25 carbon atoms, preferably from 10 to 20 carbon atoms. Suitable monocarboxylic acids include lauric acid, oleic acid and stearic acid. Other acids in this molecular weight range with more unsaturation, such as linoleic, or with ring structures, such as abietic, or with relatively high molecular weight, such as erucic, are suitable. Ketoacids, such as obtained from fatty acid ketene dimers, are also suitable. Mixtures of acids may be used. For example, commercial lauric acid containing minor amounts of capric and myristic acids is suitable.
Representative examples of polyethylene glycol diesters contemplated for use in this invention include polyethylene glycol 1000 (PEG 1000) dioleate, polyethylene glycol 1000 (PEG 1000) distearate, polyethylene glycol 1540 (PEG 1540) dilaurate and polyethylene glycol 4000 (PEG 4000) dioleate. The number which appears after the polyethylene glycol in the above designation represents the degree of polymerization of the polyethylene glycol. More specifically, the number appearing in the designation "polyethylene glycol 1000" indicates that the number of ethylene oxide units in the polymeric compound are such as to yield a total average molecular weight of about 1000. Similarly, polyethylene glycol 4000 has a total average molecular weight of about 4000.
The ASA/emulsifier compositions of the present invention are formed by mixing 70 to 99.5 parts by weight, preferably 80 to 98 parts, of the substituted succinic anhydride with 0.5 to 30 parts by weight, preferably 2 to 20 parts, of the polyethylene glycol diester. These ASA/emulsifier combinations are easy to make at a central location and can be stored and shipped to the location where the ASA emulsions will be made. The two components are miscible and the mixture is liquid at ambient temperatures.
This ASA/emulsifier composition readily emulsifies into water of various hardness and pH with simple mixing in the absence of high shear. Fine droplets are formed and the emulsion is stable until it is used for treating a surface which contains groups reactive to the anydride. The time between formation and use could range from a few seconds to several hours. Longer times are generally not preferred because the anhydride groups will gradually be hydrolyzed by the water present.
The water used can be relatively pure or can contain the usual impurities in domestic water. It can have a pH above or below 7, generally in the range of 3 to 11. Calcium and magnesium hardness ions may be present.
The amount of ASA suspended in the water can vary widely, from a few parts per million to 10% or more depending on the use and method of application. For wood or fabric treatement, concentrations around 1% may be used, whereas for internal paper sizing, the concentration in the pump slurry is normally below about 100 parts per million. Thereby about 0.1 to 1% of ASA is finally absorbed on the paper.
Surfaces to be treated with the ASA/emulsifier compositions of the invention to gain water repellency will contain integral groups which are reactive to the ASA anydride group. This normally will involve reaction with groups such as hydroxyl, amino or mercapto. A preferred type of material which may be treated with emulsions of the compositions of the invention contains carbohydrate molecules, such as cellulose or starch, at the surface of the material. These materials contain many hydroxyl groups which can react with the ASA.
As stated above, the ASA/emulsifier compositions of the present invention may be used to impart water repellency to cellulosic materials. The water-repellent compositions described above are preferably applied to the material in aqueous emulsions. The emulsion may be sprayed onto the material or the material may be dipped into the emulsion in order to distribute the derivative evenly throughout the material. The impregnated material is then withdrawn from the solution and air dried. After air drying, the material is then heated, preferably to a temperature in excess of 100° C., to effect a curing of the impregnated agent within the material. It has been found that one may conveniently use a temperature of about 125° C. for a period of 15 to 20 minutes. At lower temperatures, longer periods of time are required to effect the curing process. To be commercially practical, the curing time should be as short as possible and generally less than one hour. At higher temperatures, the heat curing may be accomplished in shorter periods of time. The upper limit of temperature at which the heat curing process may be carried out is limited to the temperatures at which the cellulosic material begins to decompose. Using the composition of the present invention, it is preferred to impregnate the material with from about 0.5 to 3% by weight of the material of the ASA/emulsifier composition.
The ASA/emulsifier compositions of the present invention may additionally be used as paper sizing agents. These novel sizing agents display all of the features and advantages of prior art sizing agents. Moreover, the novel sizing agents of this invention impart to paper sized therewith a particularly good resistance to acidic liquids such as acid inks, citric acid, lactic acid etc. as compared to paper sized with the sizing agents of the prior art. In addition to the properties already mentioned, these sizing agents may also be used in combination with alum as well as with any of the pigments, fillers and other ingredients which may be added to paper. The sizing agents of the present invention may also be used in conjunction with other sizing agents so as to obtain additive sizing effects. A still further advantage is that they do not detract from the strength of the paper and when used with certain adjuncts will, in fact, increase the strength of the finished sheets. Only mild drying or curing conditions are required to develop full sizing value.
The actual use of these sizing agents in the manufacture of paper is subject to a number of variations in technique, any of which may be further modified in light of the specific requirements of the practitioner. It is important to emphasize, however, that with all of these procedures, it is most essential to achieve a uniform dispersal of the sizing agent throughout the fiber slurry, in the form of minute droplets which can come in intimate contact with the fiber surface. Uniform dispersal may be obtained by adding the sizing agent to the pulp or by adding a previously formed, fully dispersed emulsion. Chemical dispersing agents may also be added to the fiber slurry.
Another important factor in the effective utilization of the sizing agents of this invention involves their use in conjunction with a material which is either cationic in nature or is, on the other hand, capable of ionizing or dissociating in such a manner as to produce one or more cations or other positively charged moieties. These cationic agents, as they will be hereinafter referred to, have been found useful as a means for aiding in the retention of sizing agents herein as well as for bringing the latter into close proximity to the pulp fibers. Among the materials which may be employed as cationic agents in the sizing process, one may list alum, aluminum chloride, long chain fatty amines, sodium aluminate, substituted polyacrylamide, chromic sulfate, animal glue, cationic thermosetting resins and polyamide polymers. Of particular interest for use as cationic agents are various cationic starch derivatives including primary, secondary, tertiary or quaternary amine starch derivatives and other cationic nitrogen substituted starch derivatives, as well as cationic sulfonium and phosphonium starch derivatives. Such derivatives may be prepared from all types of starches including corn, tapioca, potato, waxy maize, wheat and rice. Moreover, they may be in their original granule form or they may be converted to pregelatinized, cold water soluble products.
Any of the above noted cationic agents may be added to the stock, i.e., the pulp slurry, either prior to, along with, or after the addition of the sizing agent. However, in order to achieve maximum distribution, it is preferable that the cationic agent be added either subsequent to or in direct combination with the sizing agent. The actual addition to the stock of either the cationic agent or the sizing agent may take place at any point in the paper making process prior to the ultimate conversion of the wet pulp into a dry web or sheet. Thus, for example, these sizing agents may be added to the pulp while the latter is in the headbox, beater, hydropulper or stock chest.
Further improvements in the water resistance of the paper prepared with these novel sizing agents may be obtained by curing the resulting webs, sheets, or molded products. This curing process involves heating the paper at temperatures in the range of from 80° to 150° C. for periods of from 1 to 60 minutes. However, it should again be noted that post curing is not essential to the successful operation of this invention.
The sizing agents of this invention may, of course, be successfully utilized for the sizing of paper prepared from all types of both cellulosic and combinations of cellulosic with non-cellulosic fibers. The cellulosic fibers which may be used include bleached and unbleached sulfate (kraft), bleached and unbleached sulfite, bleached and unbleached soda, neutral sulfite, semi-chemical chemiground-wood, ground wood, and any combination of these fibers. These designations refer to wood pulp fibers which have been prepared by means of a variety of processes which are used in the pulp and paper industry. In addition, synthetic fibers of the viscose rayon or regenerated cellulose type can also be used.
All types of pigments and fillers may be added to the paper which is to be sized with the novel sizing agents of this invention. Such materials include clay, talc, titanium dioxide, calcium carbonate, calcium sulfate, and diatomaceous earths. Other additives, including alum, as well as other sizing agents, can also be used with these sizing agents.
With respect to proportions, the sizing agents may be employed in amounts ranging from about 0.05 to about 3.0% of the dry weight of the pulp in the finished sheet or web. While amounts in excess of 3% may be used, the benefits of increased sizing properties are usually not economically justified. Within the mentioned range the precise amount of size which is to be used will depend for the most part upon the type of pulp which is being utilized, the specific operating conditions, as well as the particular end use for which the paper is destined. Thus, for example, paper which will require good water resistance or ink holdout will necessitate the use of a higher concentration of sizing agent than paper which does not.
The folowing examples are provided to illustrate the invention in accordance with the principles of this invention but are not to be construed as limiting the invention in any way except as indicated by the appended claims.
EXAMPLES
Examples 1-4
Mixtures of ASA with prior art emulsifiers were made to test emulsifying power and storage stability. The ASA used in these experiments was a commercially available product made from maleic anhydride and a C 15-20 straight-chain olefin mixture. Roughly equal amounts of each carbon number are present and the double bond position in the starting olefin mixture was almost all internal. The average molecular weight corresponds to about 17.4 carbons in the olefin mixture.
The emulsifiers utilized are typical examples of prior art emulsifiers. They correspond to the four types of emulsifiers described in U.S. Pat. No. 4,040,900 (Re 29,960) as being effective ASA emulsifiers. Igepal CO-630 is a commercial alkylphenol ethoxylate containing about 9 moles of ethylene oxide obtained from GAF. Tergitol TMN-6 is a C 12 alcohol ethoxylate obtained from Union Carbide. PEG 400 monooleate and PEG 600 dilaurate are a monoester and diester, respectively, of polyethylene glycol (PEG). The PEG average molecular weight is indicated by the notations 400 and 600.
In each example, the emulsifier was dissolved in the liquid ASA at the concentration shown in Table 1. A test of the emulsifying power was made when the mixture was freshly mixed and again after it was aged. Aging was done either by sitting at room temperature for several days or by accelerated aging at 80° C. One hour at 80° C. was equivalent to about 3 days at room temperature and 3 hours at 80° C. was equivalent to about 10 days at room temperature.
the results in Table 1 show that each type of emulsifier is effective when freshly mixed, but all four types demonstrate very poor storage stability.
Examples 5-8
For Examples 5-8, the same ASA was used and the same procedure was followed as in Examples 1-4, except that the emulsifiers utilized demonstrate the teaching of the present invention. The emulsifiers are all diesters produced from polyethylene glycol whose molecular weight ranges from 1000 to 4000 and which is esterified with lauric, oleic and stearic acids.
The results in Table 1 show that these emulsifiers are surprisingly good when freshly mixed with ASA and fully retain their emulsifying power on aging.
Example 9
The procedure of Example 7 was followed except that various ASA compounds were used separately in place of the ASA described previously. In each case, 10% of PEG 1000 dioleate was added. The emulsifiability was tested fresh and after heating for 3 hours at 80° C. The ASA compounds used were:
(1) a branched ASA derived from tetrapropylene;
(2) a branced ASA derived from hexapropylene;
(3) isooctadecyl ASA;
(4) isooctadecenyl ASA; and
(5) a C 20 ASA derived from a dimer of C 10 straight-chain alpha olefin.
In each case, satisfactory emulsions were formed both when the mixture was fresh and after aging.
TABLE 1______________________________________Storage Stability of ASA/Emulsifier MixturesEx- Emulsionample Emulsifier Type.sup.1 % Storage Rating.sup.2______________________________________1 Igepal iii 7 Fresh Excellent CO-630 7 3 days at R.T. Poor 7 7 days at R.T. Ineffective 10 Fresh Excellent 10 1 hour at 80° C. Poor2 Tergitol iv 10 Fresh Fair TMN-6 10 1 hour at 80° C. Poor3 PEG 400 ii 10 Fresh Excellent Monooleate 10 1 hour at 80° C. Poor4 PEG 600 i 10 Fresh Good Dilaurate 10 1 hour at 80° C. Fair 10 3 hours at 80° C. Ineffective5 PEG 1540 i 10 Fresh Good Dilaurate 10 3 hours at 80° C. Excellent6 PEG 1000 i 10 Fresh Good Distearate 10 3 hours at 80° C. Good7 PEG 1000 i 10 Fresh Good Dioleate 10 3 hours at 80° C. Excellent8 PEG 4000 i 10 Fresh Fair Dioleate 10 3 hours at 80° C. Good______________________________________ .sup.1 (i) Fatty Acid Diester, (ii) Fatty Acid Monoester, (iii) Alkylphenol Ethoxylate, (iv) Alcohol Ethoxylate. .sup.2 Tested by shaking 1 drop in 25 ml. water; emulsion appearance and turbidity observed over 24 hour period.
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A stable composition comprising a hydrocarbyl-substituted succinic anhydride and a polyethylene glycol diester emulsifier. There is also disclosed a method for imparting water repellency to surfaces containing groups reactive to anhydrides and a method for the sizing of paper using said composition.
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BACKGROUND OF THE INVENTION
The present invention relates to shaving devices.
Shaving devices of different types are known in the art. Usually, during the use of a shaving device with razor blades, first the user applies a shaving cream on the skin and distribute it over the skin and then the shaving device with the razor is used to shave the hair. The known shaving devices possess several disadvantages. First of all, they are not used for applying and distributing the shaving cream on the skin. It is necessary to apply to distribute the shaving cream on the skin by an additional device or by hand which is inconvenient and unpleasant. The known shaving devices with razor blades do not massage the user's skin during shaving. These and other disadvantages make desirable to improve the construction of existing shaving devices.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a new and improved shaving device, which avoids the disadvantages of the prior art.
In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a shaving device which has a hollow handle with an inner chamber, a head, means for supplying the shaving cream from the inner chamber of the handle through the head onto the user's skin, bruch means for distributing the shaving cream on the user's skin, and shaving means for shaving the user's hair.
When the shaving device is designed in accordance with the present invention, it simultaneously applies and distributes the shaving cream and shaves the hair on the user's skin. When the shaving device is provided with additional massaging means, it also massages the skin which further improves the quality of the shaving. The inventive device is easy to wash, much more convenient to sue since it simultaneously performs several operations.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, 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 DRAWINGS
FIG. 1 shows a front view of the device in accordance with the present invention;
FIG. 2 is a view showing a rear of the device in accordance with the present invention;
FIG. 3 is a side view of the device in accordance with the present invention;
FIG. 4 is a partial view from below of the inventive device without a handle;
FIG. 5 is a front view of a head of the inventive device;
FIG. 6 is a rear view of the head of FIG. 5;
FIG. 7 is a side view of the head of the inventive device;
FIG. 8 is a view from below of the head with a central unit and a push button;
FIG. 9 is a view from below of the head with a brush attachable to the head;
FIG. 10 is a front view of the head with the handle of the inventive device;
FIG. 11 is a rear view of the inventive head;
FIG. 12 is a side view of the central unit;
FIG. 13 is a side view of the inventive head associated with the central unit;
FIG. 14 is a view showing a spring for assembling the device;
FIG. 15 is a side view of the push button associated with the spring of the central unit;
FIG. 16 is a view showing one of the fixing elements for fixing the push button in the central unit;
FIG. 17 is a rear view of the push button;
FIG. 18 is a rear view of the handle with a pump;
FIG. 19 is a top view of the handle with a pump for supplying shaving cream;
FIG. 20 is a view showing a piston of the pump for the shaving cream;
FIG. 21 is a bush for the pump;
FIG. 22 is a spring for the shaving cream pump;
FIG. 23 is a spring for assembly;
FIG. 24 is a push button for the shaving cream pump;
FIG. 25 shows the push button of FIG. 24 together with the bush of FIG. 20;
FIG. 26 is an end view of the push button shown in FIG. 24;
FIG. 27 is a view showing the pump for shaving cream on an enlarged scale;
FIG. 28 shows a ball to be inserted in the pump;
FIG. 29 is a view showing a bush for the pump of FIG. 27;
FIG. 30 is a view showing a pipe for connecting the shaving cream pump with the central unit and then with the head;
FIG. 31 is a view showing a lower pipe extending from the shaving cream pump to the shaving cream reservoir in the handle; and
FIGS. 32 and 33 are a rear view and a side view of a shaving element.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As can be seen from FIGS. 1 and 2, the device in accordance with the present invention has a handle which is identified as a whole with reference numeral 1. The handle has an inner hollow with a wider part 2 provided with a thread 3 closeable by a plug 4 provided with a further thread 5. The handle 1 also has a narrow part 6 of an oval cross-section.
A head 7 is mounted on the handle 1. The head has longitudinal passages 8 with outlet openings 9 which are offset radially from the axes of the passages 8. Balls 10 are retained in the recesses 9 and provided with a plurality of very small depressions 11. The balls 10 are retained in the recesses 9 by shoulders 12 projecting slightly beyond the maximum radius of the balls forwardly.
A central unit 13 is connectable with the head 7 by interengagement of a projection 14 provided in the head with the projections 15 provided in the central unit. Cylinders 16 in which the passages 8 are formed engage in a recess 17 provided at the front end of the central unit 13. A bush 18 projecting forwardly from the center unit 13 engages between the cylinders 16. Bushes 19 are located in the interior of the central unit 13 and can carry springs 20 in the assembled condition. Projections 21 of a push button 22 extend into the interior of the bushes 19 and have arresting formations 23 which are arrested pistons 24 movable in the passages 8. Arresting formations 25 fix the button 22 in the interior of the central unit 13. The elements 16, 24, 20, 23, 21 and 22 form together a pump for sucking water preferably warm water into the passages 8 and then expelling warm water from the passages 8 toward the balls 10. Openings 25 provided on the front surface of the head serve for passing the water therethrough into the passages 8 and from the passages 8. The openings 25 communicate by connecting passages 26 with the passages 8.
A pump for supplying a shaving cream 2 to the central area of the head between the balls 10 includes an inlet pipe 27, a housing 28 located in the handle and having cylinder portions 29, 30 and 31, valve members 32 and 33 located in the cylinders 29 and 30, a push button 34 provided with a spring 35 and a rod 36 which is connected with a piston 37 movable in the cylinder 38. A bush 39 is located rearwardly of the piston 37 and has a central opening 40 through which the projections 36 extend to engage the piston 37.
The head 7 is provided with a guide 41 formed for example with a dove-tail shaped groove 42. A shaving element 43 is movable in the groove 42. The shaving element includes a holder 44 with a front end on which a shaving cartridge 45 is fittable. The shaving element has a rear part 46 provided with a passage 47 for receiving a spring 48 and a ball 49. The bottom wall of the groove 42 is provided with two depressions 50 and 51. The shaving element 43 can move along the groove 42 and be fixed in its rear position shown in FIG. 3 in a solid line or a front position shown in a broken line.
Brushes 52 are insertable in recesses 53 formed at the sides of the head 7. The brushes 52 project forwardly somewhat beyond the front surface of the balls 10.
The head has openings 54 for supply water into the cylinders 8. The head also has a central passage 55 communicating with an outlet opening 56 for supplying the shaving cream.
The device operates in the following manner:
First of all, the button 22 is pushed forwardly toward the front end of the head or toward the balls 10 so that the pistons 24 are brought actually in contact with the rear surface of the ball 10. Then the head is immersed into a warm water and the button 22 is released. Under the action of the spring the button is moved to the right in an opposite direction and pulls the pistons 24 away from the balls so that the warm water is aspirated into the passages 8 through the openings 54. Then the push button 34 is pushed inwardly and released several times so that it moves back under the action of the spring. During the rearward movement of the piston 37 the shaving cream is aspirated through the pipe 27 from the inner hollow of the handle into a chamber formed between the balls 32 and 33. During subsequent push of the button 34 inwardly, the dose of the shaving cream is pressed through the cylinder 30 into the pipe 30' and then exits through the tubular element 18 through the central opening 56. When the head is applied on the skin of the user, the paste is expelled on the skin and the head is moved along the skin, the shaving cream is applied to the skin, the balls then rotate and entrain a thin film of water from the passages 8 so as to apply it on the layer of the shaving cream on the skin, and the brushes 53 uniformly distribute the shaving cream and water and make a foam on the skin. When the skin of the user is covered with the foam the shaving element 43 is moved from its rear position to its front position, and the user shaves the hair on the skin by the razor 45 of the shaving element 43. It is however possible to apply the shaving cream on the skin without supplying additional water.
The invention is not limited to the details shown since various modifications and structural changes are possible without departing in any way from the spirit of the present invention.
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The shaving device has a hollow handle accommodating the shaving cream, a head, a supply element for supplying the shaving cream from the inner chamber of the hollow handle through the head onto the user's skin, a brush for distributing the shaving cream on the user's skin, and a shaving element for shaving the user's hair after the application of the shaving cream.
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This is a continuation of copending application Ser. No. 642,792, filed on Jan. 18, 1991, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for preparing compositions of the formula REBa wherein REBa 2 Cu 4 O y is a rare-earth element, including yttrium and dysprosium and subscript "y" is about 8.0. These compositions have particular utility in superconductors. The process of the instant invention utilizes nitric acid in the preparation of the compositions. The present invention further relates to a process of preparing a superconductor from these compositions.
2. Background of the Invention
Recently, REBa 2 Cu 4 O y (hereinafter referred to as RE-124, where RE is yttrium and/or dysprosium (Dy) and subscript "y" is about 8.0, has competed with REBa 2 Cu 3 O y 0 (hereinafter referred to as RE-123, where RE is yttrium and/or dypsrosium) as one of the most important superconductors being studied. Particular interest has focused on the advantages RE-124 has over RE-123. For example, although RE-123 generally manifests a higher superconducting temperature (Tc, generally expressed in units of Kelvin, K) than RE-124 (about 90K for RE-123, and about 80K for RE-124), it suffers from having high chemical reactivity as well as poor thermal stability. Thus when heated or stored for long periods of time, RE-123 decomposes, which decomposition results in a reduction in oxygen content and, consequently, a lowering of the superconducting temperature.
In contrast, RE-124 exhibits no such chemical reactivity and further has superior thermal stability due to its particular crystalline structure. Indeed, RE-124 will not decompose even at elevated temperatures, such as when heated up to 850° C. As a result RE-124 does not suffer a loss of oxygen with the attendant depression of the superconducting temperature, which behavior is important for practical applications. Moreover, the superconducting temperature of RE-124 can be raised to about 90K --the approximate superconducting temperature of RE-123--by doping with a suitable amount of calcium. So marked are the advantages inherent in RE-124 that even its use as a precursor, i.e., a decomposition precursor, in the preparation of RE-123 has benefits: products thus made will exhibit higher hysteresis, as well as higher critical current density. Furthermore, RE-123 prepared using RE-124 as a decomposition precursor exhibits shielding effects which are superior to those exhibited by RE-123 prepared by any other process.
The known processes for manufacturing RE-124 high Tc superconductors fall into two general categories, namely: a high oxygen pressure process and an ambient oxygen pressure process. Literature related to the high oxygen pressure process include:
a) J. Karpinski, et al., Nature, 336, Dec. 15, 1988, pp. 660-662 report the synthesis of bulk RE-124 phase in oxygen at a pressure of 400 bar and a temperature of 1,040° C.
b) D. E. Morris, et al., Phys. Rev. B., 39, No. 10, pp. 7347-7350 (1989) report that an RE-124 (more particularly, Y-124) was sintered in high pressure oxygen (the pressure of O 2 being approximately 120 atmospheres) at 930° C. for 8 hours using a commercial high-pressure oxygen furnace.
c) T. Miyatake, et al., Physica C., 160, pp. 541-544 (1989) describe a sample preparation of RE-124 by a solid state reaction method using the oxygen-HIP treatment. Starting materials were calcined at 900° C. in flowing oxygen for 12 hours. The powder compact was sintered at 800° C. in flowing oxygen. The oxygen-HIP treatment was repeated twice in an argon-oxygen gas environment (Argon +20% oxygen) at a pressure of 100MPa. The first treatment was at 950° C. for 6 hours; the second at 1050° C. for 3 hours
The disadvantages common to these methods include the need for a high pressure oxygen furnace and the need for reaction temperatures over 900° C. These requirements increase production costs and are unfavorable for mass production, thus making the high oxygen pressure process unattractive for practical applications.
Literature related to the ambient oxygen pressure process include:
a) R. J. Cava, et al., Nature, 338, pp. 328-330 (1989) report a method of using Y(NO 3 ) 3 xH 2 O, Ba(NO 3 ) 2 and Cu(NO 3 ) 2 xH 2 O as starting materials which, after slow preheating and pulverizing, are mixed with an approximately equal volume of Na 2 CO 3 or K 2 CO 3 to catalytically enhance the reaction rate. The carbonate mixture is ground and heated at 800° C. for 3 days. However, the hydrated nitrates are hygroscopic, making the control of the stoichiometry difficult. In addition, impurities can be introduced by adding Na 2 CO 3 or K 2 CO 3 , thus complicating the whole process.
b) S. Jin, et al., Physica C., 165, pp. 415-418 (1989) describe a synthesis route using YBa 2 Cu 3 O 7 (the formula corresponds to RE-123 where RE is yttrium: Y-123) as a precursor. The Y-123 was mixed with CuO. Sintering was at 810°-830° C. for 3 days and was repeated 3-4 times. The disadvantages of this process include the need for a Y-123 precursor and the lengthy sintering time.
c) D. M. Pooke, et al., Phys. Rev. B., 41, No. 10 pp. 6616-6620 (1990) report a process which comprises mixing stoichiometric proportions of Y 2 O 3 , Ba(NO 3 ) 2 , and CuO with up to a 0.2 mol fraction of NaNO 3 or KNO 3 ; prereacting the mixture as a loose powder for 30 min; then grinding, die pelleting and reacting at 800° C. for at least 12 hours in flowing oxygen. Phase purity is improved with repeated grinding and sintering. The disadvantages of this process include the use of alkali nitrates which are known to introduce impurities and the lengthy sintering time.
Thus despite intensive research efforts, the problems attendent current methods of preparing RE-124 demonstrate that a need for a more efficient process exists.
SUMMARY OF THE INVENTION
The present invention is directed to a process for preparing a composition of the general formula REBa 2 Cu 4 O y , where RE represents one or more rare earth elements of atomic numbers 57 to 71, including yttrium, and subscript "y" is about 8.0. Compositions having this formula include the material known as RE-124; that is, the composition where RE is yttrium and/or dysprosium. The process of the instant invention comprises the steps of heating a mixture of at least one rare earth oxide, at least one barium compound, at least one copper oxide, nitric acid and optionally, water; the heating is under conditions sufficient to dry the mixture. The dry mixture is then calcined at a temperature of at least about 700° C. for a time of at least about 3 hours to obtain the desired composition.
Advantageously, the process of the instant invention permits more ready control over the stoichiometry of the starting materials than has heretofore been possible. This control is believed related to the presence of nitric acid, the use of which eliminates the contamination problems of prior art processes, such as contamination attributable to alkali nitrates, carbonates and the like, as caused by cations related to these materials.
The present invention is further directed to the preparation of a superconductor--such as an RE-124 superconductor--utilizing the compositions formed by the present process. The preparation of the superconductor, in accordance with the present invention, comprises the steps of compacting the composition thus prepared, followed by sintering the compacted composition under conditions sufficient to form a superconductor.
Notably, the preparation of the superconductor in accordance with the present invention utilizes lower sintering temperatures and shorter sintering times than previously possible. Moreover, the superconductor process of the instant invention requires fewer pulverizing and compacting, or pelletizing, steps than heretofore required. The overall result is that the superconductor preparation process of the subject invention requires less expensive equipment, reduces utility costs and can be readily adapted to large scale production --all the while maintaining the requisite high phase purity.
Although the scope of the processes of the present invention is independent of any theory explaining its superior effects, it is theorized that these effects are related to a catalytic-like action on the part of the nitric acid.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an X-Ray Diffraction (XRD) pattern of Y-124 as prepared according to the present invention. Calcining was at 750° C. for 4 hours.
FIG. 2 is an X-Ray Diffraction (XRD) pattern of Y-124 as prepared according to the present invention. Sintering was at 805° C. for 15 hours.
FIG. 3 is an X-Ray Diffraction (XRD) pattern of Y-124 as prepared according to the present invention. Sintering was at 805° C. for 33 hours.
FIG. 4 is an X-Ray Diffraction (XRD) pattern of Y-124 as prepared according to the present invention. Sintering was at 805° C. for 48 hours.
FIG. 5 is an X-Ray Diffraction (XRD) pattern of Dy-124 as prepared according to the present invention. Sintering was at 805° C. for periods of 6 hours, 14.5 hours, 30 hours and 54, cumulatively.
FIG. 6 illustrates the temperature dependence magnetization curves of Y-124 and Dy-124. The superconducting temperatures of Y-124 and Dy-124 are shown to be 80K and 75K, respectively.
DETAILED DESCRIPTION OF THE INVENTION
The starting materials employed in the practice of the present invention consist of at least one rare earth oxide, at least one barium compound, at least one copper oxide, and nitric acid (HNO 3 ).
Rare earth oxides useful in the present invention include oxides formed from one or more of the rare earth elements having atomic numbers 57 to 71, including yttrium. In the preferred practice of the invention oxides of dysprosium (Dy) and/or yttrium (Y) --Dy 2 O 3 and Y 2 O 3 , respectively--are used.
Barium compounds useful in the practice of the present invention include barium compounds which contain oxygen. Especially useful in this regard are barium nitrate (Ba(NO 3 ) 2 ), barium oxide (BaO) and barium carbonate (BaCO 3 ).
The copper oxides useful in the practice of the present invention include copper compounds which contain oxygen. In the practice of the invention, copper (II) oxide (CuO) is preferred.
In the preferred practice of the invention the rare earth oxide, the barium compound and the copper oxide all have a purity of at least 99%, more preferably greater than 99%.
Water, though not necessary in the practice of the present invention, may be present among the starting materials. Indeed, in the preferred practice of the invention, water is present, resulting in an enhancement of overall processing parameters. These include a shorter sintering time when the composition thus produced is fabricated into a superconductor. Deionized water is especially preferred.
Procedurally, in the process of the invention for the preparation of the composition having the formula REBa 2 Cu 4 O y wherein the subscript "y" is about 8.0, the at least one rare earth oxide, the at least one barium compound and the at least one copper oxide are mixed in amounts corresponding to a molar ratio of rare earth to barium to copper, respectively, of about 1:2:4. Nitric acid, and water if present, may be included in this initial charge, but is preferable to add these components subsequent to forming the mixture containing the rare earth, barium and copper.
The nitric acid is added in an amount which is proportional to the amount of rare earth cation present in the mixture, the proportion being about 0.00005 to about 0.003 moles of rare earth, to about 0.5 to about 3.0 moles of nitric acid. Preferably, this proportion is about 0.00075 to about 0.0025 moles of rare earth to about 0.1 to about 2.8 moles of nitric acid. More preferably, this proportion is about 0.001 to about 0.002 moles of rare earth to about 1.2 to about 2.4 moles of nitric acid.
Water, when added to the mixture, is added in an amount of up to about 7.0 moles of water per mole of nitric acid. Preferably, this ratio is between about 0.5 to about 3.0 moles of water per mole of nitric acid. More preferably, this ratio is between about 1.6 to about 4.0 moles of water per mole of nitric acid.
The mixture, containing the nitric acid and water, if present, is then heated. Heating is continued, preferably with stirring, until the mixture is dry. The mixture at this point is generally gray in color. The dry mixture is then calcined to yield the composition . Calcining is for a time of at least about 3 hours, preferably from about 3 to about 8 hours. More preferably, from about 4 to about 6 hours. Calcining temperature is at least about 700° C.; preferably about 720° C. to about 780° C.; most preferably about 750° C. Calcining is preferably performed in the presence of oxygen, more preferably flowing oxygen (O 2 ) After calcining, the composition having the general formula REBa 2 Cu 4 O y , generally present in the form of a black powder, is recovered.
In further accordance with the present invention a process to prepare a practical, high purity REBa 2 Cu 4 O y superconductor from the composition thus prepared, is disclosed. Procedurally, for this aspect of the present invention, the composition obtained is compacted, preferably pelletized, and then sintered to form the superconductor. In the practice of this embodiment of the present invention, it may be necessary to pulverize the obtained composition prior to compaction so as to ensure uniformity and facilitate handleability.
The compacted composition is sintered under conditions sufficient to provide a superconductor having practical application. Sintering is normally accomplished at a temperature of at least about 790° C. for a time of at least about 25 hours. Preferably, sintering is performed at a temperature of about 800° C. to about 810° C. More preferably the sintering temperature is about 805° C. As to time, sintering is preferably carried out for a time period of about 30 to about 55 hours. More preferably, the sintering time is about 31 to about 33 hours. The sintering step is preferably performed in the presence of oxygen; more preferably flowing oxygen. Upon completion of the sintering step a high purity superconductor is obtained.
In a preferred embodiment of preparing a superconductor in accordance with the present invention, the sintering step is performed in stages, the accumulated time for which is the sintering time. Sintering in stages permits the composition to be periodically pulverized and re-compacted. This facilitates complete and uniform exposure of the composition to the sintering operation. Thus in the practice of this embodiment, the compacted composition is pulverized and re-compacted--into pellets, for example--between each stage, until the final sintering stage, wherefrom the superconductor is recovered, is reached.
In a preferred aspect of this embodiment, the sintering is performed in two stages wherein approximately midway through the total sintering time, the compacted composition is removed from the sintering environment, pulverized, re-compacted and returned to the sintering environment for the balance of the sintering time. Upon completion, a high purity superconductor is obtained.
The following examples are offered to assist in the understanding of the present invention and are not intended to limit the scope thereof.
EXAMPLE 1
Five samples, (a)-(e), were prepared as follows:
Into five separate beakers were charged 0.248g Y 2 O 3 (commercially available from Cerac), 1.150g Ba(NO 3 ) 2 (commercially available from Merk), and 0.700g CuO (commercially available from Merk); all had a purity of greater than 99%. These materials were mixed and the following amounts of HNO 3 were added to each of the five beakers, respectively, to generate Samples (a)-(e):
Sample (a): no HNO 3 added.
Sample (b): 25 ml HNO 3 (approximately 0.6 moles).
Sample (c): 50 ml HNO 3 (approximately 1.2 moles).
Sample (d): 75 ml HNO 3 (approximately 1.8 moles).
Sample (e): 100 ml HNO 3 (approximately 2.4 moles).
De-ionized water was added in the following amounts so that the liquid volume (HNO 3 plus water) equalled 100 mls for each sample.
Sample (a): 100 ml de-ionized water (approximately 5.6 moles).
Sample (b): 75 ml de-ionized water (approximately 4.2 moles).
Sample (c): 50 ml de-ionized water (approximately 2.8 moles).
Sample (d): 25 ml de-ionized water (approximately 1.4 moles).
Sample (e): no de-ionized water added.
The Samples (a)-(e) were then heated, while stirred, until dry. In each of Samples (a)-(e), a gray-colored mixture was obtained. Each of Samples (a)-(e) were then calcined at 750° C. for 4 hours in the presence of flowing oxygen. Each of the samples yielded a black powder. The black powders of Samples (a)-(e) were then analyzed using X-Ray Diffraction (XRD) techniques, the results of which are shown in FIG. 1.
Reference to FIG. 1 shows that Ba 2 Cu 3 O 5 and CuO are the predominant phases and that when the HNO 3 addition was 50 mls or more (which corresponded to a nitric acid to yttrium molar ratio of about 1.2 to 2.4 moles of nitric acid to approximately 0.0022 moles of yttrium), a composition having the formula YBa 2 Cu 4 O y , (also known as Y-124) begins to appear.
The powders of Samples (a)-(e) were then pulverized and compacted under a pressure of 100 kgf/cm 2 into pellets having a diameter of 10 mm. The pellets corresponding to Samples (a)-(e) were then sintered at a temperature of 805° C. for 15 hours in the presence of flowing oxygen. The resultant pellets were then analyzed by XRD, the results of which are shown in FIG. 2.
Reference to FIG. 2 shows that where the addition of HNO 3 was 50 mls or more, as in Samples (c), (d) and (e) (which corresponded to a nitric acid to yttrium molar ratio of about 1.2 to 2.4 moles of nitric acid to about 0.0022 moles of yttrium), the yield of Y-124 phase increases rapidly.
The pellets of Samples (a)-(e) were pulverized and pelletized for a second time, the conditions being the same as the first time, and were sintered again at 805° C. for 18 hours in the presence of flowing oxygen the cumulative sintering time at this point was 33 hours). The resultant pellets were analyzed by XRD. The results are shown in FIG. 3.
Reference to FIG. 3 shows that when the addition of HNO 3 was 50 mls, Sample (c), (which corresponded to a nitric acid to yttrium molar ratio of about 1.2 moles of nitric acid to about 0.0022 moles of yttrium) the result was nearly single phase Y-124. For Samples (d) and (e) the result was similar: near Y-124 single phase was obtained. Samples (d) and (e) (75 mls and 100 mls of HNO 3 , respectively, the corresponding nitric acid to yttrium molar ratios were about 1.8 moles of nitric acid to about 0.0022 moles of yttrium for Sample (d), and about 2.4 moles of nitric acid to about 0.0022 moles of yttrium for Sample (e)) are shown in FIG. 3 as not having been completely reacted. Samples (a) and (b) (0 mls and 25 mls of HN03, respectively) did not show the appearance of Y-124 phase.
The pellets of Samples (a)-(e) were sintered further at 805° C. for 15 hours in the presence of flowing oxygen (the total accumulated sintering time was 48 hours). The pellets were recovered and analyzed by XRD, the results are shown in FIG. 4.
Reference to FIG. 4 shows that Samples (d) and (e) now yielded almost solely Y-124 after the sintering time had totalled 48 hours. Samples (a) and (b) did not show the emergence of a Y-124 phase even after 48 hours of sintering.
The pellets of Samples (a)-(e) thus obtained were tested with a Superconducting Quantum Interference Device (SQUID) for diamagnetism and superconducting temperature, Tc. The results are shown in FIG. 6.
Reference to FIG. 6 shows that the superconducting temperature, Tc (in degrees of Kelvin, K) of the Y-124 prepared in accordance with Example 1 was 80K. This value is in accord with that which is published in the literature.
EXAMPLE 2
The following materials were charged into a beaker: 0.208 g Dy 2 O 3 (commercially available from Cerac), 0.440 g BaCO 3 (commercially available from Merk), and 0.355 g CuO (commercially available from Merk); all had a purity greater than 99%. These materials were mixed and 30 mls of HNO 3 (approximately 0.7 moles), corresponding to a nitric acid to dysprosium molar ratio of about 0.7 to 0.001, was added Deionized water was then added in an amount of 60 mls to dilute the HNO 3 to a total solution volume of 90 mls.
The sample was heated, while stirred, until dry. A gray-colored mixture was obtained. The mixture was then calcined at 750° C. for 6 hours in the presence of flowing oxygen; a black powder resulted. The black powder thus obtained was pulverized and compacted into a pellet having a 10 mm diameter.
The pellet was then sintered at 805° C. in the presence of flowing oxygen for time periods of 6 hours, 14.5 hours, 30.5 hours and 54 hours cumulatively. XRD analysis was performed after each sintering period; the results are shown in FIG. 5.
Reference to FIG. 5 shows that a nearly single phase of the composition having the formula DyBa 2 Cu 4 O y , known as Dy-124, was obtained when the sample was sintered at 805° C. for 30.5 hours. FIG. 5 also shows that when the sintering time was increased to 54 hours, the phase content of Dy-124 remained substantially unchanged.
SQUID measurement showed the superconducting temperature, Tc of the Dy-124 thus prepared was 75K. This result is shown in FIG. 6. This value of Tc is in accord with that which is published in the literature.
In conclusion, the present invention is characterized by using HNO 3 as a reaction enhancer which permits the preparation of compositions having the general formula REBa 2 Cu 4 O y , such as Y-124 and Dy-124, and superconductors using these compositions in much shorter times, at lower temperatures and with simplified operation. Consequently, expensive equipment is not required and production cost is reduced. Further, the stoichiometries are easily controlled since hygroscopic hydrated nitrates are not used as starting materials, and no alkali metal impurities are introduced because no alkali carbonates or nitrates are added.
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A process for preparing a composition having the general formula REBa 2 Cu 4 O y where RE is a rare earth element such as dysprosium and including yttrium and the subscript "y" is about 8.0. The process utilizes nitric acid among the starting components to provide control over stoichiometry and minimize contamination. The present invention is also directed to a process of preparing a high purity superconductor utilizing the composition thus prepared. This process permits the superconductor to be prepared in a short time and at low sintering temperatures.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] This invention relates to an apparatus and method for testing load bearing capacity on a pile or group of piles. In one aspect, this invention relates to novel apparatus and method for testing load bearing capacity on a pile or group of piles, utilizing a reaction anchor apparatus and method.
[0003] 2. Background
[0004] In the construction industry, various types and shapes of piles are utilized for constructing foundations on the piles. These foundations are the structural supports upon which many types of constructions are built. Foundations support the loads imposed upon them and, hence, the loads imposed upon the piles, by such constructions as high rise buildings, power plants, river dams, and many other constructions.
[0005] Among the most common types and shapes of piles are timber piles, steel pipe piles, H-Piles, L-Piles, precast concrete piles, and cast-in-place concrete piles. These piles are installed vertically or battered at an angle.
[0006] Piles are forced deep down into the soil by repetitive blows on their tops. These powerful blows are provided by pile-driving machines, also known as hydraulic hammers. Piles also can be poured-in, i.e., cast-in-place, by drilling a deep hole in the soil, then filling it with concrete. Generally, reinforcement steel rods, also known as rebar, are introduced into the hole prior to filling it with concrete.
[0007] The most commonly used method of installation of piles is by beating them down into the ground by means of a pile-driving machine.
[0008] Through the years, the construction industry has developed apparatus and testing methods for determining the capability of a vertical pile, a batter pile, or a group of piles to resist a required level of static compression loads as actually applied on the pile or group of piles. These testing methods determine whether a pile or group of piles has adequate bearing capacity or not.
[0009] Testing methods have been standardized by the American Society for testing materials, also known as ASTM. The Standard Test Method For Piles Under Static Axial Compressive Load, designation D1143-81, (reapproved 1987) covers pile testing utilizing conventional apparatus and methods for determining the capability of piles to resist a static compression load as actually applied on the piles.
INTRODUCTION TO THE INVENTION
[0010] According to ASTM D1143-81, single piles must be tested to 200% of the anticipated design load, while pile groups must be tested to 150% of the group design load.
[0011] Conventionally, for testing an individual pile, two additional piles have to be installed, using the same method and equipment utilized for installing the pile under test. These additional piles are driven into the soil on two diametrically opposing sides of the pile to be tested and at not less than seven feet from the pile being tested. These additional piles are known in the trade as anchor piles.
[0012] A test beam then is installed across the tops of the anchor piles, tying them to the beam and above the pile under test, forming what is known in the trade as a reaction frame. This test beam is set on a hydraulic jack, which in turn is set on top of the pile under test.
[0013] Upward hydraulic push is applied by the jack against the beam. The beam cannot move up because it is tied onto the anchor piles. As a result, the hydraulic power, i.e., the force exerted by the hydraulic jack, is applied downwardly against the top of the pile under test. These forces are applied incrementally, increasing at pre-established time intervals and held then at the maximum predetermined test loading for a specified length of time.
[0014] Certain instrumentation is utilized for determining the axial loading and for determining any movements, e.g., axial, rotational, and lateral, of the pile under test.
[0015] If the test proves the capability of the pile to resist the specified axially applied compressive loading, and if there are no other deviations beyond acceptable standards, then that pile is determined to be fit to be used for its intended purposes, i.e., it has adequate bearing capacity.
[0016] Testing a group of piles instead of a single pile utilizes the same procedure, but in the case of a group of piles, the various piles in the group are capped by a common cap, and the test load is applied uniformly upon the pile cap. Pile caps generally are poured, reinforced concrete slabs, specifically engineered for that purpose. A larger number of anchor pile pairs is required when testing pile groups.
[0017] After the test, anchor piles are left in place, after sawing off their tops, i.e., after sawing-off the top portion of the pile protruding above ground. It is extremely difficult and expensive to pull those anchor piles out of the ground.
[0018] Utilizing anchor piles for testing an installed pile or a group of piles presents several drawbacks.
[0019] One drawback of the conventional pile testing apparatus and methods is the large installation cost of driving into the soil one, two, or more pairs of anchor piles per each single pile or group of piles to be tested.
[0020] Another drawback of the conventional pile testings is the difficulty in handling the long and heavy anchor piles required for the testings, e.g., requiring a tractor and a trailer for their transportation, requiring a special crane for lifting in or out of the trailer, requiring an expensive, cumbersome pile driving machine for driving the anchor piles into the ground.
[0021] Another drawback of the conventional pile testings is the difficulty of setting the long and heavy anchor piles in a vertical position for driving them into the ground.
[0022] Yet another drawback of the conventional pile testings is the loss of the anchor piles, because after the test is completed, they are not reusable in future tests, and therefore, their top ends protruding above the ground have to be sawed off, abandoning the pile in the ground.
[0023] It is an object of the present invention to provide anchoring apparatus and installation methods which substantially reduce the cost of testing piles or group of piles.
[0024] Another object of the present invention is to provide anchoring apparatus and methods which simplify the pile testing process.
[0025] Yet another object of the present invention is to provide anchoring apparatus and methods for the testing of piles which simplify transportation and eliminate utilizing a tractor and a trailer.
[0026] Still another object of the present invention is to provide anchoring apparatus and methods for the testing of piles which do not require the use of a pile driving machine.
[0027] Another object of the present invention is to provide anchoring apparatus and methods for the testing of piles which do not require the use of anchor piles for the pile testing process.
[0028] Yet another object of the present invention is to provide anchoring apparatus and methods for the testing of piles which are reusable.
[0029] These and other objects of the present invention will become apparent from a careful review of the detailed description and the figures of the drawings, which follow.
SUMMARY OF THE INVENTION
[0030] The apparatus and method of the present invention provide novel means and method for testing piles for load bearing capacity. The novel means and method of the present invention include applying a static compressive force on a pile or group of piles to be tested for load bearing capacity, receiving an equal and opposite reaction force on an I-beam, providing at least two reaction anchor assemblies on opposite sides of the pile, and bracing the I-beam by the two reaction anchor assemblies to hold the I-beam stationary in counter-action against the opposite reaction force on the I-beam. In one aspect, each reaction anchor assembly has an anchoring head, a pipe column, a center, a pulling rod passing through the center, a pair of swingable anchoring plates and preferably two pairs of swingable anchoring plates, and a frusto-cone for pivoting the swingable anchoring plates. In one aspect, the pipe column has four fins welded longitudinally along the pipe column. In one aspect, the reaction anchor assembly is preassembled for transportation to a pile test site. The novel means and method for testing piles provide for retrieving the reaction anchor assemblies from the ground after completion of the pile test and reusing the reaction anchor assemblies from one pile test site to another.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] [0031]FIG. 1 is an elevation view showing the single pile testing apparatus of the existing art.
[0032] [0032]FIG. 2 is an elevation view showing the pile group testing apparatus of the existing art.
[0033] [0033]FIG. 3 is an elevation view, partially in section, showing a single pile testing apparatus of the present invention. FIG. 3 also shows some measuring instruments.
[0034] [0034]FIG. 4 is a perspective view of FIG. 3 without showing instrumentation.
[0035] [0035]FIG. 5 is an elevation view, partially in section, of a reaction anchor and support assembly in accordance with the apparatus and methods of the present invention. FIG. 5 shows a hydraulic assembly utilized for anchoring the reaction anchor and support assembly, also in accordance with the apparatus and methods of the present invention.
[0036] [0036]FIG. 6 is a detail view of a hydraulic system component part of the present invention, shown in elevation.
[0037] [0037]FIG. 7 is a detail elevation view of a hydraulic system component part of the present invention, also showing a load cell and a read-out with a graph print out.
[0038] [0038]FIG. 8 is a detail perspective view of a rod-centering box component part of the present invention shown in elevation on FIG. 3. FIG. 8 shows a centering and support plate lifted up from the box.
[0039] [0039]FIG. 9 is an elevation view, partially in section, showing a pile group testing apparatus of the present invention, utilizing a concrete pile cap. FIG. 9 also shows some measuring instruments.
DETAILED DESCRIPTION
[0040] [0040]FIG. 1 and FIG. 2 depict apparatus and method representing the conventional testing apparatus and method for testing vertical piles, as shown on ASTM D1143-81 (reapproved 1987). FIG. 1 depicts the conventional testing apparatus and method for testing a single pile. FIG. 2 depicts the conventional testing apparatus and method for testing a group of piles.
[0041] Referring now to FIG. 1, a single pile 1 is shown as having been driven into soil 17 . A pair of anchor piles 7 also have been driven into soil 17 , at a distance at least seven feet away from or clear of pile 1 , i.e., away from the pile 1 under test. A bottom flange 19 of a test beam 6 is set on top of a bearing plate 5 of a piston ram 4 of a hydraulic cylinder 2 . The hydraulic cylinder 2 is set on a test plate 3 , which is centered on top of the individual pile 1 , i.e., the single pile 1 .
[0042] The test beam 6 is tied to the anchor piles 7 by means of a series of connecting rods 8 , a pair of plates 9 on a top flange 18 of the beam 6 , and the connecting rods 8 are secured by a series of threaded nuts 10 , threaded down against the plates 9 .
[0043] By the conventional method, a powerful, upwardly driven push is provided by the piston ram 4 of the hydraulic cylinder 2 , as represented by an arrow 15 . This upwardly driven push is exerted upon the test beam 6 , by means of a bearing plate 5 , which bears on the bottom flange 19 of the beam 6 . The beam 6 is fixedly connected to the anchor piles 7 by means of the threaded nuts 10 , tightened on the connecting rods 8 , against the plates 9 . As a result, the beam 6 cannot move up. The forceful push of the pistons 4 is effectively resisted by the anchor piles 7 because of the friction between the anchor piles 7 and the soil 17 . An equivalent forceful push therefore is exerted downwardly on the test plate 3 and, as a result, on the individual pile 1 .
[0044] Accordingly to ASTM D1143-81 (reapproved 1987), the load applied upon the pile 1 , which is the pile under test, must be 200% of the anticipated individual pile 1 design load.
[0045] The scope of purpose for testing piles is to determine if the pile has adequate bearing capacity, by measuring the response of the pile, e.g., the pile 1 , to a static, compressive load, axially applied, as shown by an arrow 16 of FIG. 1.
[0046] In addition, pile testings also are utilized for measuring pile movements under axial loading. FIG. 1 shows a pair of dial gages 11 , connected by means of a pair of stems 20 to the pile 1 , at a pair of lugs 14 and to a pair of reference beams 13 by means of a pair of supports 12 .
[0047] Referring now to FIG. 2, the conventional testing apparatus and method for a group of piles 40 is represented. Pile group 40 includes, by the way of an example, the two piles 40 which have been driven into a soil 53 . A series of anchor piles 47 also have been driven into the soil 53 at a distance at least seven feet away from or clear of any pile 40 , i.e., the pile 40 of the pile group under test. A bottom flange 57 of a test beam 56 is set on top of a bearing plate 45 of a ram 44 of a hydraulic cylinder 43 . The hydraulic cylinder 43 is set on a test plate 42 , which in turn is set on a pile cap 41 . The pile cap 41 is centered on top of pile group 40 . The pile cap 41 is constructed of reinforced concrete, which is engineered to bear the anticipated load.
[0048] The test beam 56 has a pair of beams 61 on its top flange 46 . A pair of beams 58 are set with their bottom flanges 59 on top of the I-beams 61 . This I-beam set up is all tied down to the anchor piles 47 by means of a series of connecting rods 48 and threaded nuts 52 , with a plate 51 on top of each flange 60 . The threaded nuts 52 are tightened down against the plates 51 .
[0049] By the conventional method, a powerful, upwardly driven push is provided by the piston 44 of the hydraulic cylinder 43 , as represented by an arrow 54 . This upwardly driven push is exerted upon the test beam 56 by means of the bearing plate 45 , which bears on the bottom flange 57 of the beam 56 . The beam 56 is fixedly connected to the anchor piles 47 by means of the threaded nuts 52 tightened on the connecting rods 48 , against the plates 51 . As a result, the beam 56 cannot move up. The forceful push of the piston 44 is effectively resisted by the anchor piles 47 because of the friction between the piles 47 and the soil 53 . An equivalent, forceful push is exerted therefore downwardly upon the test plate 42 , the pile cap 41 , and the pile group 40 , as represented by an arrow 55 .
[0050] Accordingly to ASTM D1143-81 (reapproved 1987), the load applied upon the pile group 40 , which is the pile group under test, must be 150% of the anticipated pile group 40 design load.
[0051] These ASTM tests are performed to determine if the pile group has adequate bearing capacity by measuring the response of the pile group, e.g., the pile group 40 , to a static, compressive load applied axially, as shown in FIG. 2.
[0052] The pile group 40 also is tested to determine movements which occur under loading. FIG. 2 shows a pair of dial gages 51 connected by means of a pair of stems 49 to a pile cap 41 and to a pair of reference beams 53 by means of a pair of supports 52 .
[0053] Referring now to FIG. 3, a pair of reaction anchor and support assemblies 125 in accordance with the apparatus and the methods of the present invention are shown in the process of testing a single pile 90 under a static, axial load, provided by a hydraulic assembly 145 . The reaction anchor and support assemblies 125 provide a point of resistance for a pair of hydraulic cylinders 93 to push against, as the hydraulic cylinders 93 exert a specified testing load on the pile 90 , as further described in this detailed description. The reaction anchors and support assemblies 125 are manufactured by SAFE Foundations, Inc., of Pittsburgh, Pa.
[0054] The hydraulic cylinders 93 are set on a bearing plate 91 , also known as a test plate 91 , with a pair of pistons 94 , respectively, upon which a bearing plate 92 is set. The hydraulic assembly could include only a one cylinder and one piston set instead of the pair of cylinders and pistons as shown in FIGS. 3 and 6. A load cell 121 is set between the bearing plate 92 and a bearing plate 122 . The bearing plates 91 , 92 , and 122 are of sufficient thickness to support the test loads provided by the hydraulic assembly 145 without bending, but not less than two inches thick.
[0055] The plate 122 bears against a flange 142 of a novel I-beam assembly 116 . The I-beam assembly 116 bears against an I-beam assembly 115 , which is identical to the beam assembly 116 . A pair of flanges 143 of the I-beam assembly 115 are set on top of a pair of flanges 105 of the I-beam assembly 116 . The beam assembly 115 is set at ninety degrees of the beam assembly 116 and on top of the beam assembly 116 , as shown in FIG. 4, a perspective view, showing some of the elements shown in FIG. 3.
[0056] Referring now to FIGS. 3, 4, and 8 , each of the beam assemblies 115 and 116 is constructed of two parallel I-beams, with one rod centering box 96 at each end of each assembly 115 and 116 . A detail of the rod centering box 96 is shown in FIG. 8, a perspective view of rod centering box 96 .
[0057] One box 96 is welded at each end of each beam assembly 115 and 116 . The boxes 96 are made of plates 99 welded to the top flanges 105 and 106 of the beam assembly 116 and 115 , respectively, and of L-shaped bars 100 , also welded to the flanges 105 and 106 , respectively. The rod centering boxes 96 are completed by plates 97 , also welded to flanges 105 and 106 respectively. The plates 99 are also welded to the angled bars 100 and to the plates 97 . Angled bars 104 are welded to each end of the I-beams 115 and 116 , respectively. With one rod centering box 96 , and one angled bar 104 welded to each end of each pair of I-beams, very strong, novel reaction frames, i.e., beam assemblies 115 and 116 , are formed. Support plates 101 , shown lifted-up from box 96 in FIG. 8 are utilized to receive threaded rods 102 of the reaction anchor and support assemblies 125 . Nuts 103 in FIGS. 3 and 4 are threaded onto the rods 102 and tightened against the support plates 101 . The plates 101 can slide inside their respective centering box 96 to facilitate positioning the beam assemblies 115 and 116 over rods 102 .
[0058] Referring now to FIGS. 3 and 7, the hydraulic assembly 145 is shown set upon the test plate 91 . The test plate 91 is set on top of the pile 90 , which is the pile under test, as shown in FIG. 3.
[0059] To test the pile 90 for determining its capability of supporting its design load, a compressive load is axially applied upon the longitudinal axis of the pile 90 , the compressive load being provided by the hydraulic assembly 145 .
[0060] The pistons 94 of the hydraulic assembly 145 forcefully push, upwardly, against the bearing plate 92 . This upward push of the pistons 94 is transmitted to the beam assemblies 115 and 116 . Since the beam assemblies 115 and 116 are anchored by the reaction anchor and support assemblies 125 , the beam assemblies 115 and 116 cannot move upwardly. The forceful upward push of the pistons 94 , as they are forced out of their respective cylinders 93 , is actually exerted axially, downwardly upon the pile 90 , by means of the bottoms of the cylinders 93 , upon the bearing plate 91 .
[0061] Referring to FIG. 3, a pair of dial gages 109 have their stems 118 connected to a top surface 191 of the bearing plate 91 and to a pair of reference beams 110 by means of a pair of supports 147 . The stems 118 must have, at a minimum, two inches (5 cm) of travel, must have a precision of at least 0.01 inches (0.25 millimeters) and must read to one sixty-fourth ({fraction (1/64)}) of an inch (4 mm).
[0062] The dial gages 109 provide the measurement of any longitudinal axial movement of the pile 90 under the axial loading provided by the hydraulic assembly 145 . Any axial movement beyond that specified renders the pile 90 unacceptable for its specified load.
[0063] Referring to FIGS. 3 and 6, the hydraulic assembly utilized in the apparatus and the method of the present invention could include a single hydraulic cylinder with its piston or a pair of cylinders 93 of a hydraulic assembly 95 of FIG. 6, with a pair of pressure gages 117 , one pressure gage 117 for each hydraulic cylinder 93 and a master pressure gage 116 , and further includes a hydraulic pump 113 and an automatic pressure control device 114 . The cylinders 93 are connected to the pump 113 by a pair of common manifolds 111 and hoses 112 . The complete hydraulic assembly 95 is to be calibrated as a unit, including the hydraulic cylinders 93 , the pistons 94 , the pressure gages 117 and 116 , the pump 113 , and the automatic pressure control device 114 .
[0064] [0064]FIG. 7 represents the preferred embodiment of the hydraulic means utilized by the apparatus and the methods of the present invention. The hydraulic assembly 145 is very similar to the hydraulic assembly 95 . Nevertheless, the hydraulic assembly 145 utilizes a calibrated load cell 121 between the bearing plate 92 and the bearing plate 122 . In accord with the apparatus and the methods of the present invention, the calibrated load cell 121 is connected to a read-out and load graph recorder 124 . The read-out recorder 124 provides a graph 148 showing the load applied during a 24 -hour period. The calibrated load cell 121 and the read-out and load graph recorder 124 substantially improve the accuracy and reliability of the measurements of the loads applied to the pile-under-test 90 . The preferred embodiment for the hydraulic means, e.g., the hydraulic assembly 145 , also includes the pressure gages 117 , one for each hydraulic cylinder 93 and the master pressure gage 116 , the hydraulic pump 113 , and the automatic pressure control 114 . The cylinders 93 are connected to the pump 113 by the common manifolds 111 and the hoses 112 . This apparatus and method provide a dual measuring system. The load cell 121 must be calibrated to an accuracy of not less than 2% of the applied load.
[0065] Referring again to FIG. 3, the reaction anchor and support assemblies 125 , also referred to as anchor assemblies 125 , are shown inside earthen holes 126 . The reaction anchor and support assemblies 125 include anchoring heads 133 and a pipe column 128 , which has four fins 129 , only three shown, welded longitudinally to the surface of pipe column 128 and at ninety degrees to each other. The pipe columns 128 also have top plates 130 welded to their tops, which have a center hole to allow Dywidag Rod 102 pass through it, with a minimum clearance, in order to allow Dywidag nuts 132 to be tightened against the plates 130 when threaded down on the Dywidag rods 102 . The Dywidag rods, the nuts, and other Dywidag products are manufactured by DywidagSystems International, U.S.A., Inc., of Fairfield, N.J.
[0066] The anchoring heads 133 have the Dywidag rods 125 and a plate support 138 formed by four ninety-degree bars, only two being shown, with a plate 137 welded on their top and four compaction and consolidation pivoting plates 139 , only three being shown. A collar 135 is welded on top of the plate 137 and is utilized to insert end 134 of the pipe column 128 into the collar 135 or over the collar 135 , depending on pipe sizes utilized. Four bolts 136 , only three shown, are utilized for firmly securing the pipe column 128 to the anchor head 133 . The Dywidag rod 102 is inserted through a centerhole in a frusto-cone 140 . A Dywidag nut 141 is threaded on the end of the rod 102 and prevents the frusto-cone 140 from falling down.
[0067] A nut 168 is hand tightened on the Dywidag rod 102 , on top of the frusto-cone 140 , as seen in FIG. 4. The main purpose of the nut 141 is to carry the frusto-cone 140 upwardly whenever the rod 102 is pulled up, during the process of anchoring the reaction anchor and support assembly 125 , prior to installing the test beam assemblies 115 and 116 .
[0068] During the installation of the reaction anchor and support assemblies 125 , hydraulic force is utilized for pulling up on the rod 102 . The pulling on the rod 102 forces the nut 141 to push the frusto-cone 140 upwardly, which in turn pushes the compaction and consolidation pivoting plates 139 upwardly and outwardly. The pulling on the rod 102 makes the pivoting plates 139 swing upwardly and outwardly, thereby compacting and consolidating soil 127 at the bottom of the earthen hole 126 , effectively anchoring the assembly 125 against the soil 127 at the bottom of the earthen hole 126 , thus providing the reaction point needed for the pile test. A nut 132 is threaded downwardly and hand tightened against the plate 130 at the top of the pipe column 128 in order to prevent the rod 102 and the frusto-cone 140 from moving back down.
[0069] The top end of the reaction anchor and support assembly 125 is left a few inches above grade in order to facilitate its retrieval for further use. Holes 131 are utilized for hooking a lifting device.
[0070] The reaction anchor and support assemblies 125 are installed at a distance of at least seven feet, clear distance, from the pile 90 .
[0071] The pile 90 of FIG. 3 is shown as a round, cylindrical pile. Nevertheless, the pile 90 can be an H-pile, an L-pile, a square pile, or an orthogonal pile. The pile 90 can be a concrete pile, whether cast-in-place or pre-cast, a pipe pile, or a timber pile, by the way of an example.
[0072] The test set up shown in FIG. 3 requires four reaction anchor and support assemblies 125 , as shown in FIG. 4, in order to provide an anchored reaction capacity, which is greater than the axial load applied to the pile 90 by the hydraulic assembly 145 . The axial loading or test loading required for testing single piles is at least 200% of the pile design load capacity. Nevertheless, smaller piles require smaller test loads, and only one pair of reaction anchor and support assemblies 125 are required for smaller piles.
[0073] On occasion, three pairs of reaction anchor and support assemblies 125 are required. In such cases, an additional beam assembly is installed upon the beam assembly 115 and at forty-five degrees from it. The additional pair of reaction anchor and support assemblies are installed as shown for the beam assemblies 115 and 116 and in a substantially similar manner as shown for the reaction anchor and support assemblies 125 of FIGS. 3 and 4.
[0074] Referring now to FIG. 5, one reaction anchoring and support assembly is shown of the four reaction anchoring and support assemblies of FIGS. 3, 4, and 9 . The one reaction anchoring and support assembly is shown in the process of being installed inside a pre-augured earthen hole 126 , in preparation for utilization in the testing of the single pile 90 of FIG. 3 or group pile 180 of FIG. 9.
[0075] The reaction anchor and support assembly 125 of FIG. 5 provides the anchored reaction capacity required to resist the upward push of the hydraulic assemblies 145 of FIGS. 3, 4, and 9 . The upward push of the hydraulic assemblies 145 provides the resultant downward axial loading required for testing the single pile 90 of FIG. 3 or the group pile 180 of FIG. 9.
[0076] The reaction anchor and support assemblies 125 are brought to the test site in one piece, pre-assembled, with the anchoring head 133 pre-attached to the rod 102 and with the rod 102 inside the pipe column 128 . The compaction and consolidation pivoting plates 139 come to the test site vertically down and parallel to the rod 102 , with the frusto-cone 140 below the tip end of the compaction and consolidation pivoting plates 139 . The frusto-cone 140 is sandwiched between the nut 168 , on its topside, as shown in FIG. 4 and the nut 141 on its bottom side as shown in FIG. 5. The pivoting plates 139 come with breakable tie-wire (not shown) around them, in order to keep them in a vertical position, which facilitates lowering down the anchor assembly 125 inside the pre-augured earthen hole 126 . The nut 132 comes to the test site hand tightened against the plate 130 .
[0077] The reaction anchor and support assembly 125 is lowered down inside the earthen hole 126 . About six inches of the top end of the reaction anchor and support assembly 125 is left above ground level 166 . A centering collar 163 is placed over the assembly 125 and pushed down inside the earthen hole 126 , until its plate 162 rests on surface 166 of the soil 126 . The collar 163 is about twelve to eighteen inches long. The centering collar 163 is utilized for centering the reaction anchor assembly 125 inside the earthen hole 126 and to make sure it is fixed in a true, vertical and leveled position. When the correct leveling is attained, four pins 165 (only two are shown) are hammered down into the soil 127 , through holes 164 of the plate 162 , in order to immobilize the centering collar in a vertical position.
[0078] Next, the hydraulic assembly 150 is placed over the rod 102 , i.e., with the rod 102 passing through openings 155 and 156 on plates 152 and 153 , respectively. This is done by means of a crane, which is available at the job site anyways for handling the piles. The hydraulic assembly 145 of FIG. 7 could be utilized instead of the hydraulic assembly 150 of FIG. 5, if plates 91 , 92 , 94 , and the load cell 121 had an opening through their center, for allowing the rod 102 pass through it.
[0079] The preferred embodiment provides for utilizing one single hydraulic assembly to perform both the installation of all the reaction anchor and support assemblies 125 prior to testing, as well as providing the specified loading for testing the single pile 90 of FIG. 3 or the pile group 180 of FIG. 9. In such an embodiment, the load cell 121 also has a center hole. If the load cell 121 also is utilized for installing the anchor assembly 125 , then it could be installed between the plate 91 of FIG. 7 and the plate 130 of FIG. 5. The utilization of the load cell 121 and the read-out/graph recorder 124 is not a requirement for the installation of the reaction anchoring and support assemblies 125 . Nevertheless, the utilization of the load cell 121 and the read-out/graph recorder 124 is an additional quality control feature as well as a record keeping feature and a component part of the present invention.
[0080] When the hydraulic assembly 150 is set on top of the plate 130 , a plate 167 is placed over the rod 102 and set on top of the plate 153 to reduce the actual size of opening 156 so that the Dywidag nut 103 can be threaded down on the rod 102 and hand tightened against the plates 167 and 153 .
[0081] The hydraulic assembly 150 has cylinders 151 connected by means of hoses 158 through the assembly's inlets 157 to a hydraulic pump 159 . A master pressure gage 168 is provided in series with both the cylinders 151 and the pump 159 . A pressure gage 169 provides a reading of the pressures applied by the pistons 154 , in pounds per-square inch, p.s.i. The total force exerted by the assembly is directly proportional to the diameter of pistons 154 . The diameter of the pistons 154 determines the area in square inches of the cross section of each piston 154 , which pistons 154 are substantially identical pistons. Therefore, the total combined area is determined in advance.
[0082] The operator is provided with a simple table showing how many tons-force are equivalent to various p.s.i. readings from the gage 169 . The operator does not calculate anything. The compaction and consolidation pivoting plates 139 are at the bottom of the earthen hole 126 in a vertical position parallel to the rod 102 . The next step is to swing upwardly the pivoting plates 139 to anchor the assembly firmly against the soil 127 at the bottom of the hole 126 .
[0083] The operator provides hydraulic pressure to the cylinder 151 , through the bottom inlets 157 , which forces the pistons 154 upwardly. The pistons 154 forcefully push against the plates 153 , 167 and the nut 103 . That forceful upward push as represented by arrows 160 and as exerted on the nut 103 , which is threaded onto the rod 102 , lifts the rod 102 up, which in turn carries the nut 141 up with it. The nut 141 is threaded to the bottom end of the rod 102 . The nut 141 pushes up the frusto-cone 140 , which in turn forces the pivoting plates 139 to break their tie-wire (not shown). The pivoting plates 139 are forced to swing upwardly, compacting and consolidating the soil 127 at the bottom of the hole 126 by the expanding plates, i.e., by the expansion of the pivoting plates 139 , thereby powerfully anchoring assembly the 125 to the soil at the bottom of the hole 126 . As the rod 102 is being slowly, yet powerfully pushed upwardly, the operator hand-tightens down the nut 132 against the plate 130 , thereby preventing the pivoting plates 139 from collapsing back down, which is a very rear situation.
[0084] Now the hydraulic assembly 150 is removed, by first reversing the flow of hydraulic fluid, which now is pumped by the pump 159 , through the upper inlets 157 , which in turn brings the pistons 154 back inside of their respective cylinders 151 . Then the hydraulic pressure is released and the nut 103 and the plate 167 are removed. Finally, the hydraulic assembly 150 is removed and the installation of the next anchoring assemblies 125 can be started, until all four assemblies required per FIG. 3, 4 and 9 are installed.
[0085] Preferably, the centering collar 163 stays installed, one on each anchoring assembly 125 until the pile test is concluded and the anchoring assemblies 125 are removed.
[0086] As opposed to the conventional methods, whereby the anchor piles utilized in the testing remain in the ground and their tops must be sawed off, the reaction anchoring and support assemblies 125 are reusable.
[0087] The anchoring and support assemblies 125 are retrievable. They are retrieved from the earthen hole 126 utilizing the same hydraulic assembly they were installed with.
[0088] In order to retrieve the reaction anchor and support assemblies 125 from the earthen hole 126 , after the pile testing is completed, first the operator places the hydraulic assembly 150 once more over the rod 102 , by means of an on-site crane. Then the operator lowers the assembly down so that the rod 102 passes through the hole 155 on the bottom plate 152 and through the hole 156 of the top plate 153 . Now, the plate 167 is reinstalled, and the nut 103 is rethreaded down on the rod 102 and hand tightened against the plate 167 .
[0089] The operator then pumps hydraulic fluid through the lower inlets 157 , by means of the pump 159 . This forces the pistons 154 out of their respective cylinders 151 , slowly but forcefully pushing upwardly against the plates 153 and 167 and on the nut 103 which, being threaded onto the rod 102 , slowly lifts the rod 102 upwardly. This is done just enough to release the enormous pressure exerted by the nut 132 against the plate 130 at the time the anchor and support assembly 125 was installed. Now the operator threads the nut 132 upwardly on the rod 102 and then releases the pressure from the pump 159 , which releases the upward push of the pistons 154 .
[0090] Next the nut 103 and the plate 167 are removed, and the operator pumps again hydraulic fluid through the lower inlets 157 , by means of the pump 159 , to make the pistons 154 extend out of the cylinders 151 for a distance which is approximately equal to the distance the pistons 154 were extended during the process of installation. The hydraulic assembly then is lifted up again, by means of a crane, just enough, so that the top end of the rod 102 is below the plate 153 , in order to allow re-introducing the plate 167 , which now will be on top of the nut 132 , which has been threaded up.
[0091] Then, the operator lowers down the hydraulic assembly and sets its bottom plate 152 back on top of the plate 130 of the reaction anchor and support assembly 125 and with the rod 102 passing through the hole 156 of the top plate 153 .
[0092] The operator further threads up the nut 132 carrying the plate 167 upwardly until the plate 167 is against the bottom of the plate 153 with the nut 132 hand-tightened under it.
[0093] Now the operator pumps hydraulic fluid through the upper inlets 157 , which forces the pistons 153 back down, slowly but forcefully pushing downwardly on the nut 132 , which now is under the plates 167 , 153 and is threaded onto the rod 102 . Therefore the pistons 154 , slowly yet powerfully, push the rod 102 down. Since the nut 168 , shown on FIG. 4, is threaded onto the rod 102 and it is on top and in contact with the frusto-cone 140 , it pushes the frusto-cone 140 also downwardly. By pushing the frusto-cone 140 downwardly, the compaction and consolidation pivoting plates 139 are effectively released from the powerful force which kept them pressed against the soil at the bottom of the earthen hole 126 .
[0094] With the pivoting plates 139 collapsed back down to a vertical position, now the hydraulic assembly can be finally removed, as previously described, after releasing the hydraulic pressure.
[0095] A job-site crane then is utilized for lifting the anchor and support assembly 125 out of the earthen hole 126 . Openings 131 on fins 129 are utilized for helping in lifting the assembly by means of devises and the job-site crane.
[0096] Referring now to FIG. 9, the reaction anchor and support assemblies 125 , utilized by the methods of the present invention, are shown in the process of testing a pile group 180 under a static axial load provided by the hydraulic assembly 145 .
[0097] The pile group 180 includes two or more single piles 182 . The pile group 180 is capped with a reinforced concrete cap 181 engineered and constructed specifically for the anticipated test loads.
[0098] The hydraulic cylinders 93 are set on the bearing plate 91 , with their respective pistons 94 , upon which the bearing plate 92 is set. The load cell 121 is set in between the bearing plate 92 and the bearing plate 122 . The bearing plates 91 , 92 and 122 are of sufficient thickness to support the test loads provided by the hydraulic assembly 145 without bending, but not less than two inches thick.
[0099] The plate 122 bears against the flange 142 of I-beam assembly 116 . The I-beam assembly 116 bears against the I-beam assembly 115 , which is identical to the beam assembly 116 . The flanges 143 of the I-beam assembly 115 are set on top of the flanges 105 of I-beam assembly 116 . The beam assembly 115 is set at ninety degrees of the beam assembly 116 in the horizontal plane and on top of it.
[0100] The construction of the I-beam assemblies 115 and 116 of FIG. 9 is substantially the same as described in reference to FIGS. 3 and 4. The hydraulic assembly 145 of FIG. 9 also is substantially the same as described in reference to FIGS. 3 and 7. Nevertheless, for the pile group 180 testings, a larger axial load is required, for a larger capacity for the hydraulic cylinders 93 , with their respective pistons 94 , possibly, of larger diameter than it would be required for single pile testings.
[0101] The reaction anchor and support assemblies 125 of FIG. 9 are also substantially the same as described in reference to FIGS. 3, 4 and 5 . On occasion, a third pair of assemblies 125 is utilized in order to provide the reaction capacity required for the loading specified for a specific pile group test.
[0102] Continuing to refer to FIG. 9, the instrumentation set up is substantially similar to that described in reference to FIG. 3. Nevertheless, for the group pile testing of FIG. 9, the dial gages 109 have their stems 118 connected to the top of the concrete cap. The dial gages 109 are connected to reference the beams 110 by means of the supports 147 . The stems 118 must have, at a minimum, two inches (5 Cm) of travel, must have a precision of at least 0.01 inches (0.25 millimeters) and must read to one sixty-fourth ({fraction (1/64)}) of an inch. These dial gages provide the measurement of any longitudinal axial movement of the pile group 180 under the axial load provided by the hydraulic assembly 145 . Any axial movement beyond that specified, renders pile 90 unacceptable for its specified load.
[0103] Other instrumentation means are available for measuring other single pile and group pile movements under axial test loadings.
[0104] By the novel methods of the present invention, single piles or group piles are tested utilizing one, two, or more pairs of reaction anchor and support assemblies, as shown in FIGS. 3, 4, and 9 and as described in the detailed description, instead of utilizing one, two, or more pairs of anchor piles which cannot be reutilized for future pile or pile group tests.
[0105] The testing process of the present invention does not depart from the procedures established by the A.S.T.M. standards for testing piles or pile groups. The novelty of this invention includes the utilization of the novel anchor and reaction anchoring and support assembly in combination with the novel I-beam assembly, with a built-in centering box. This combination, in addition to its reusability feature, is a safer and more reliable anchoring system than the conventional anchor piles utilized by the conventional methods. The mechanical connections between the conventional reaction beam and the conventional anchor piles of the conventional methods are substantially more susceptible to elongation under the axial pressures involved in the test than the Dywidag rod and Dywidag nuts combination utilized by this invention.
[0106] The component parts of the reaction anchor and support assembly of this invention have been utilized under axial loadings several times larger than the loads involved in pile tests.
[0107] The safety and reliability of the methods of this invention are demonstrated further by the anchoring method of this invention, which compacts and consolidates the soil it is anchored to, with the compaction and consolidation increasing, thus increasing the anchoring capacity, as the test loading increases. This can be understood readily by looking at the drawings in FIGS. 3, 5, and 9 , showing the swingable pivoting plates anchored and pushing upwardly, at the bottom of an earthen hole, such that the more the test load pulls up on the Dywidag rod, the more powerfully the anchoring head gets anchored to the soil at the bottom of the hole.
[0108] The apparatus and method of the present invention substantially contrast with the conventional anchor piles, which depend absolutely on the friction between the pile and the soil into which it was hammered down. In the conventional application, the more the test load pulls the anchor pile up, the greater are the chances the pile will slide up, and often the piles do slide up.
[0109] As it can be seen by a review of the detailed description, the apparatus and method of the present invention accomplish all of its stated objectives. The apparatus and methods of the present invention are capable of modifications and variations without departing from the scope thereof. Accordingly, the detailed description and examples set forth above are meant to be illustrative only and are not intended to limit the scope of the invention as set forth in the appended claims.
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A novel apparatus and method are disclosed for testing piles for load bearing capacity. The novel means and method of the present invention include applying a static compressive force on a pile or group of piles to be tested for load bearing capacity, receiving an equal and opposite reaction force on an I-beam, providing at least two reaction anchor assemblies on opposite sides of the pile, and bracing the I-beam by the two reaction anchor assemblies to hold the I-beam stationary in counter-action against the opposite reaction force on the I-beam. In one aspect, each reaction anchor assembly has an anchoring head, a pipe column, a center, a pulling rod passing through the center, a pair of the swingable anchoring plates, and a frusto-cone for pivoting the swingable anchoring plates. In one aspect, the pipe column has four fins welded longitudinally along the pipe column. In one aspect, the reaction anchor assembly is preassembled for transportation to a pile test site. The novel means and method retrieve the reaction anchor assemblies from the ground after completion of the pile test and reuse them from one pile test site to another.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an optical reproducing device and more particularly, is suitable for use in a optical disc player wherein a laser beam is used to read information, such as audio or video signals, recorded on a track of a disc in the form of pits.
2. Description of the Prior Art
In an optical reproducing device such as an audio or video disc player, a light beam is used to read an information signal carried by a rotating record carrier in which pits are formed on a track of the record carrier.
To ensure that the reading light beam is always directed on a track during the reading of the carrier, the focusing spot of the beam must be adjustable in an axial direction so that it can follow the track. It is to be appreciated that in general, the moving carrier is not perfectly flat.
The focusing point of the laser spot along the optical axis of the beam may be adjusted in several ways. One way is to move the reading lens or focusing lens along its axis by an electromagnetic motor moving perpendicularly to the plane of the carrier.
The electromagnetic motor can be controlled by a focusing control system which includes a detecting means for detecting the focusing deviation or error of the reading beam. The detecting means, in general, detects the focusing error on the basis of reproduced signals from the track. Since the dynamic ratio of the detecting means is usually very low, the focusing control system has a very narrow capture range, for example, about ±10 μm. Outside this range it is impossible to detect a focus error, yet the focus control system is not properly locked.
At the beginning of a reproduction operation, therefore, it is necessary initially to bring the laser spot close to the focussed position so that the control system remains stable during subsequent operation.
Lens movement can also be performed by another control system which always moves the lens in the same direction from a rest position until it is positioned within the capture range or pickup zone of the focusing control system. The control system or capture range search system has a speed control loop for moving the lens at a constant speed, because, if the speed is too high, the system will evershoot the pickup zone.
The speed control loop includes a speed sensor for detecting the speed of the lens driven by the electromagnetic motor. When the motor has a moving-coil arrangement, such as a dynamic loudspeaker, a counter electromotive voltage induced across the moving-coil may be representative of the moving speed of the lens. It is, however, difficult to represent the moving speed accurately, as the moving-coil has resistances which are affected by temperature variations. Such a conventional system, therefore, has disadvantages since the moving speed can not be maintained constant, resulting in mis-operation of the capture range search system. Also, when the speed is too high, the system may pass beyond the capture range. When the speed is too low, the system can take too much time to reach the capture range.
OBJECTS AND SUMMARY OF THE INVENTION
An optical reproducing device according to the present invention comprises an accurate approaching speed sensing means which overcomes the aforementioned difficulties of the prior art.
In particular, an improved compensation means for compensating for temperature variations is coupled to the speed sensing means and detects accurately the moving speed of the focusing lens. The system according to the present invention permits the focusing lens to move at an optimum, constant speed to the operating range of the focus control system where it can be locked into stable operation.
According to the present invention, an optical reproducing device for reproducing information from a rotating record medium with a light beam directed thereon comprises a light source such as a laser for emitting the beam through a focusing lens on to the record medium, a focus control system comprising an electromagnetic motor having a moving coil for displacing the focusing lens perpendicular to the plane of the record medium, and a capture range search system for driving the motor to move the focusing lens at a substantially constant speed from a rest position until it is positioned within the capture range of the focusing control system. The capture range search system includes a bridge circuit for sensing the moving speed of the focusing lens. The bridge circuit includes the moving coil and a variable impedance element which form two of the four sides of the bridge. The bridge circuit also includes a control circuit for controlling the variable impedance element to balance the bridge circuit when the lens is at the rest position, and a drive circuit for supplying a drive current to the moving coil of the motor in response to the output of the bridge circuit so that the output of the bridge circuit becomes nearly constant in a balanced state.
The above, and other objects, features and advantages of the invention will be apparent from the following detailed description of an illustrative embodiment thereof, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an optical system and a focus control system for a disc player in combination with an embodiment of the present invention;
FIG. 2 is a block circuit diagram of a prior art focus search control system;
FIGS. 3A-3D are waveform diagrams of various signals in the circuit of FIG. 2;
FIG. 4 is an equivalent D.C. circuit diagram of a coil of a linear drive motor when the motor is ON during a search for a focus point; and
FIG. 5 is a block circuit diagram of a focus search control system in accord with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a block diagram of an optical system and a tracking control system in a disc player used with an embodiment of the present invention. On a disc 1 information is recorded sequentially as concave or convex optical structures such pits along a volute-shaped track. Reproduced information signals are derived from a beam from a laser 2 positioned in a pickup reflected through an optical system onto a pit formed in the track on the disc 1. The reflected light beam is modulated by the pit and directed onto a photo diode array 3 to generate a signal.
The optical system comprises mirrors 4, 5, a magnifying lens 6, a polarized beam splitter 7, a 2/4 wavelength plate 8, a tracking galvanomirror 9, a focusing lens 10 and a cylindrical lens 11. A light beam from the laser 2 is reflected by the mirrors 4 and 5 upon the magnifying lens 6 whereby the beam is magnified so as to cover the aperture of the focusing lens 10. The light beam then passes through the polarized beam splitter 7 and is converted into a circularly polarized beam by the 2/4 wavelength plate. Tracking galvanomirror 9 then directs the light beam in a direction incident upon disc 1. Focusing lens 10 focuses the light beam in a fine spot on the surface of the disc 1.
The beam is modulated by a pit on the disc and is reflected, whereby the rotational direction of the circularly polarized beam is reversed. The beam thus modulated and reflected is picked up by the focusing lens 10. The reflected light beam follows the above-described optical path in reverse and is again converted to a linearly polarized beam by the 2/4 wavelength plate 8. The beam is next reflected by the polarized beam splitter 7, and then passes through the cylindrical lens 11 and strikes the photo diode array 3.
The photo diode array 3 comprise four divided elements. The outputs of two pairs of opposed photo diodes are added by adders 12 and 13, respectively, and the outputs of the adders 12 and 13 are added by an adder 14, whereby a reproduced RF signal is obtained. The reproduced RF signal is transmitted from a terminal 15 to a demodulation circuit (not shown).
The width of the track formed on the disc 1 is, in one embodiment 1.6 μm, so the diameter of a spot formed on the disc 1 is about 1.6 μm. The focusing lens 10, therefore, must generally have a large NA (Numerical Aperture). However, the depth of focus of such a lens is so shallow that surface vibration of about +10 μm of the disc 1 cause defocusing, thus causing the diameter of the spot to become larger. A number of tracks, several multiples of ten, may be irradiated with the light beam, making reproduction impossible.
To eliminate such difficulties, the focusing lens 10 is connected to a moving coil type moving mechanism such as a linear drive motor whereby a focus error caused by surface vibrations of the disc 1 are detected and, on the basis of the detected error signal, the position of the focusing lens 10 is controlled in a direction orthogonal to the surface of the disc 1. The focus error can be computed by a subtractor 16 as the difference between the signals obtained by adding the outputs of the two pairs of opposed sides of the photo diode array 3 i.e., by the signals from the adders 12 and 13, respectively.
When the focus of the focusing lens 10 is above or below the surface of the disc 1, the image of the reflected beam formed on the photo diode array 3 by the cylindrical lens 11 becomes an ellipse, as indicated by the dotted lines "a" and "b" in FIG. 1, so that subtractor 16 supplies a positive or negative focus error signal. The focus error signal is supplied to a driving coil (not shown) for the focusing lens 10 whereby the lens 10 is moved in the direction indicated by arrow A to form a focused spot on the disc surface. When a focused spot is formed on the track of the disc 1, a circular image is formed on the photo diode array 3 and a focus error signal f is zero. Two methods of detecting a focus error have been proposed. In one method, a wedge in place of the cylindrical lens 11 and, in a second method, an auxiliary beam is used.
The focus control system described above has a very narrow capture range, about ±10 μm, and outside this range it is impossible to detect a focus error and the focus control system can not be locked. At the beginning of disc reproduction, therefore, the focusing lens 10 gradually approaches the disc 1 from a position away from the disc until it is positioned within the capture range of the focus control system, and after such a focus scan or focus search, that is, after the focusing lens 10 has entered the capture range of the disc 1, the focus servo control mode is actuated.
FIG. 2 is a block diagram of a prior art control circuit for performing a focus search, and FIG. 3 is a set of waveform diagrams useful in explaining the operation of the control circuit of FIG. 2.
In FIG. 2, a coil 20 of a linear drive motor 19 connected to the focusing lens 10 is connected to one side of a bridge circuit 21, and a variable resistor 22 for balancing the bridge circuit is connected to the opposite side. The other pair of opposite sides of the bridge circuit 21 comprise resistors 23 and 24. In the focus search mode of operation, a change-over switch 25 is connected to a contact 25a to supply a driving current for the coil 20 through an output terminal of an amplifier 37 according to the output of a comparator 26, thus initiating movement of the focusing lens 10.
As the coil 20 moves, a counter electromotive voltage V is induced thereacross. FIG. 4 illustrates an equivalent D.C. circuit in this state. The circuit of FIG. 4 comprises a DC resistor "r" and an electromotive voltage V proportional to the moving speed. If the voltages at points A, B and C of the bridge circuit 21 are assumed to be V A , V B and V C , respectively, and the resistance values of the variable resistor 23 and of the resistors 23 and 24 are assumed to be R v , R 1 and R 2 , respectively, ##EQU1## When the bridge is balanced, ##EQU2## That is, if the voltages at the points B and C of the bridge circuit 21 are subtracted from each other by a subtractor 27, it is possible to derive a voltage "v" proportional to the counter electromotive voltage V (the moving speed of the coil). The voltage "v" is compared with a reference voltage E in the comparator 26, and an electric current proportional to the compared output flows in the coil 20 through the amplifier 37.
The control loop of FIG. 2 operates so that v=E, whereby the counter electromotive voltage is constant, that is, the moving speed of the coil 20 becomes constant.
In this state of constant speed control, the focus error signal f output from the subtractor 16 in FIG. 1 is fed through a terminal 30 to a zero-crossing detector 31', as shown in FIG. 2. As shown in FIG. 3A, the focus error signal is obtained as a positive or negative signal in the capture range of the focus control system and reverses in polarity before and after the focus point (focus coincident point). Consequently, from an output terminal of the zero-crossing detector 31' there is obtained a pulse representing the focus coincident point, as shown in FIG. 3B.
On the other hand, the reproduced RF signal obtained from the terminal 15 in FIG. 1 is fed through a terminal 29 to an envelope detector 31 in FIG. 2, then is transmitted to a comparator 32. The reproduced RF level of the focus error signal f also increases rapidly. Above a predetermined threshold level E t detected RF level signal from the output terminal of the comparator 32 is derived. This detected RF signal and the foregoing detected zero-crossing signal are transmitted to an AND gate 33 and a flip flop 34 which is set by a detected signal which is output from the AND gate 33. As a result, the switch 25 is moved to a contact 25b and the focus error signal f is fed to a terminal 28, as shown in FIG. 2. The signal f is supplied to the coil 20 through an amplifier 35, the switch 25 and the amplifier 37 to lock the focus control. On the other hand, when the reproduced RF signal drops to zero, the output of the comparator 32 drops to a low level, and the flip flop 34 is reset by a pulse from an inverter 36 and the switch 25 is again moved to the contact 25a whereby the focus search mode is resumed.
The focus search mode operates correctly only when the bridge circuit 21 is balanced. If the bridge circuit 21 is unbalanced, a counter electromotive force is not correctly detected, and the term V A enters equation (4), and the moving speed becomes too high or, alternatively, becomes zero, and the focus control cannot be engaged. The bridge circuit 21 is usually balanced by adjusting the variable resistor 22 at the time of manufacture, but the balance can be easily lost due to variations with time, temperature change, etc. Since the coil 20 is made of a copper wire, its temperature characteristics are poor and its specific resistance value "r" changes largely due to its self-heat-generating characteristics and changes in ambient temperature.
In order to eliminate such difficulties, a thermistor or the like has heretofore been inserted in the bridge circuit 21, but even so, it is very difficult to maintain the balance in the bridge circuit 21.
In accord with the present invention, the bridge circuit is kept balanced automatically without adjustment and the focus coincident point can be detected with certainty.
FIG. 5 is a block diagram of a focus search circuit in accord with the present invention. In this embodiment, the variable resistor 22 of the bridge circuit 21 shown in FIG. 2 is replaced by a variable impedance element 38 comprising one or more FET transistors or the like. The variable impedance element 38 is controlled, as will be described more fully below, by the output of a sample holding circuit 39. In the focus search mode, the focusing lens 10 is scanned one time at a constant speed in a direction approaching the disc 1 by a controlled oscillator 40. If the focus control system is not locked due to the presence of a flaw or the like on the disc 1, the focusing lens 10 is reset to the farthest position from the disc 1 and is again scanned in a direction approaching the disc. A control signal which has high and low levels at a period of about 5 seconds is supplied by the controlled oscillator 40 to a change-over switch 41 and the sample holding circuit 39. When this control signal is at a high level, the focusing lens 10 is moved in an upward direction, in a direction approaching the disc, while at a low level indicated in FIG. 5 as DOWN of that signal the focusing lens 10 is reset to the farthest position from the disc 1.
When the output of the controlled oscillator 40 is at a low level, the switch 41 is connected to a contact 41a and a negative bias voltage is supplied from a negative power source 42 to the coil 20 of the linear drive motor 19 through the switches 41, 25 and the amplifier 37, whereby the focusing lens 10 is stopped in the lowest position. At this time, moreover, with a low-level output of the controlled oscillator 40, a switch 43 in the sample holding circuit 39 is closed and, in the same manner as in FIG. 2, a detected moving speed voltage "v" obtained by taking the difference between the voltages at the points B and C of the bridge circuit 21 by the subtractor 27 is supplied through a low-pass filter 44 to a holding capacitor 45 in the sample holding circuit 39.
The output of the sample holding circuit 39 controls the variable impedance element 38 to balance the bridge circuit 21. The input impedance of the variable impedance element 38 is, in a preferred embodiment, very large. The control loop comprising the subtractor 27, the low-pass filter 44, the sample holding circuit 39 and the variable impedance element 38, becomes stable when the detected moving speed voltage "v" is zero, wherein the bridge circuit 21 is balanced. Since the focusing lens 10 is stationary in the lowest position, no counter electromotive voltage V is induced, and the detected moving speed voltage becomes zero if the bridge circuit is balanced. If there is any detected speed voltage "v", it is accumulated in the capacitor 45 and the terminal voltage of the capacitor increases, so the impedance of the variable impedance element 38 decreases, whereby the voltage difference between the points B and C of the bridge circuit becomes small and the detected speed voltage "v" decreases. If the voltage "v" becomes zero, the output of the capacitor 45 in the sample holding circuit 39 does not increase, the loop is stable, resulting in V B =V C , and the bridge is balanced.
In a balanced state of the bridge, if the output of the controlled oscillator 40 becomes high, the switch 41 moves to contact 41b, the switch 43 in the sample holding circuit 39 turns off, and the focus search loop is formed. Accordingly, the difference in voltage between the points B and C of the bridge circuit 21 is computed by the subtractor 27 and the detected speed voltage "v" supplied by the subtractor 27 is compared with the reference voltage E (the desired value) by the comparator 26. An error voltage is supplied by the comparator 26 to the coil 20 through the switches 41, 25 and the amplifier 37. The control loop allows current to flow in the coil 20 so that v=E, whereby the focusing lens 10 connected to the coil 20 is raised toward the disc 1 at a constant speed, as v is constant.
Once the focus coincident point is detected by the focus search, the flip flop 34 of the coincidence detection circuit of FIG. 2 is set and its high output is supplied to the switch 25 from a terminal 46, as shown in FIG. 5, whereby the switch 25 moves to the contact 25b. The focus error signal f output from the subtractor 16 is supplied from the terminal 28 to the contact 25b, as shown in FIG. 1. The signal f is supplied to the coil 20 through the amplifier 35, the switch 25 and the amplifier 37, thus allowing the focus control operation to take place.
In the present invention, as set forth hereinbefore, the variable impedance element 38 is connected to one side of the bridge circuit 21 for detecting the moving speed of the linear drive motor coil which drives the focusing lens 10, and is controlled so that the bridge circuit 21 is automatically balanced when the focusing lens is stationary, so that even when the bridge is unbalanced due, for example, in ambient, temperature or variation with time, the unbalanced bridge can be automatically restored without adjustment, and variations in the manufacture of the coil 20 can also be accommodated. As a result, it is possible to have the output of the bridge circuit 21 represent the coil moving speed without an error, and on the basis of the detected moving speed voltage the coil 20 can be moved at an optimum, constant speed, thereby permitting the foscusing lens 10 to move to the operating range of the focus control system and be locked into stable operation.
Although a specific embodiment of the present invention has been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to that precise embodiment, and that various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
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An optical reproducing device for reproducing information from a rotating record medium includes a focus control system for displacing a focusing lens perpendicular to the plane of the record medium. A light beam is conducted through the focusing lens on to the record medium. A capture range search system is provided to move the focusing lens at a substantially constant speed from a rest position until it is positioned within the capture range of the focusing control system. The capture range search system includes a bridge circuit for sensing the moving speed of the focusing lens. The bridge circuit includes a moving coil of a drive motor for said focusing lens and a variable impedance element. The bridge circuit is balanced by controlling the variable impedance element when the lens is at the rest position.
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BACKGROUND OF THE INVENTION
The present invention relates to sized paperboards. More particularly, the invention relates to novel and improved multi-ply paperboards useful in the manufacture of gypsum wallboards.
Gypsum wallboard is a well known structural precast unit useful as the wall or ceiling material of residential or industrial buildings and made of a gypsum core which has been set by hydration and two covering multi-ply paperboards which sandwich the core, the contacting surfaces being firmly bonded to each other.
Such gypsum wallboards are manufactured, according to the most widely practiced process, in the following steps or operations. An aqueous hydraulic slurry of calcined gypsum is poured into the space provided between two separate multi-ply paperboards while continuously and endlessly advancing at the same velocity. As the gypsum slurry becomes to set or hardened due to hydration to form a core sandwitched by the two covering paperboards, the whole board is passed through a high-temperature drying kiln, where most of excessive water content in the board is removed by evaporation. The thus treated board is cut into desired lengths.
The paperboard, specifically the core-side liner or ply of the multi-ply paperboard, can bond to the hardened gypsum core without the use of any adhesives in principle. This is because numerous needle-like cystals are formed in the gypsum slurry soaked in the paperboard and elongate into the texture of the paperboard, resulting in an intimately interlaced structure to produce a sufficient bonding strength between the gypsum core and the covering paperboard.
It is a conventional technique to add to the aqueous slurry of calcined gypsum small amounts of a water-soluble polymeric substance, such as starch. The addition of starch is intended, in part on one side, to produce an auxiliary adhesive bond between the gypsum core and the paperboards but, in major part on the other side, to provide coatings on the crystals of the hydrated gypsum so that any losses in bonding strength between the paperboards and the hydrated gypsum core can be prevented if and when the crystals of the hydrated gypsum (CaSO 4 .2H 2 ) is dehydrated into the state of calcined gypsum (CaSO 4 .1/2H 2 ) or further into the state of anhydrous gypsum (CaSO 4 ) during the drying step in the high temperature kiln operated at excessively high temperatures, say, above 80° C.
Important technical problems to be solved in the above-described conventional manufacturing process of gypsum wallboards include the following:
(1) The drying velocity in the drying kiln should be sufficiently high to ensure high productivity.
(2) The interlacing of the hydrated gypsum crystals and the paper texture should be well developed so as to give a sufficient bonding strength.
(3) The amount of an expensive water-soluble polymeric substance like starch to be added to the aqueous slurry of calcined gypsum should be reduced to as low as possible without causing troubles with respect to the problems (1) and (2) above.
(4) It should be realized that the starch added does not spread evenly throughout the inside and surface of the hydrated gypsum core or migrate into the entirety of the multiplied paperboards, but concentrate near the interface between the core of the hydrated gypsum and the covering paperboards.
The solution of the above problems is largely dependent on the quality of the paperboards used. For the purpose, the paperboards are required to have such qualities as high mechanical strengths, low moisture absorption, small changes in dimensions when wet, and fine appearance as well as adequate water absorptivity and high air permeability, the latter two qualities being particularly important. For example, if the air permeability of the paperboards is not sufficiently high, the dissipation of water vapors during the drying ste is hindered, and it is required disadvantageously to provide a longer drying kiln.
The water absorptivity and air permeability are, sometimes, contradictory requirements to each other for a paperboard suitable for the manufacture of gypsum wallboards. It is a very difficult problem to satisfy both requirements simultaneously. For example, conventional sizing materials, such as rosin-alum, natural waxes, acrylic resins, and the like, which are used for the purpose of decreasing the water absorptivity of the paperboards, work to remarkably reduce air permeability and, for this reason, can not be suitable for sizing paperboards to manufacture gypsum wallboards.
A method has been proposed in the prior art to solve the above-described technical problems encountered in the manufacture of gypsum wallboards, in which the paperboards are treated in advance with certain silicone resins, e.g. an epoxy-modified silicone resin (see, for example, U.S. Pat. Nos. 3,389,042 and 3,431,143). The method, however, is disadvantaged by the following reasons, and can not be satisfactory from the practical point of view.
(1) That certain expensive silicone resins are used in relatively large amounts.
(2) That the paperboards as treated with a silicone resin have to be stored for many days in accumulation before the silicone resin is sufficiently cured and the paperboards are put to processing for the manufacture of gypsum board product.
(3) That the paperboards as finished tend to have non-uniform quality due to local variations in the degree of curing, since the curing reaction of silicones is very susceptible to conditions under which the silicone-treated paperboards are stored.
In addition to the above technical problems which are principally concerned with the bottom liner ply of the multi-ply cover paper directly adjacent the gypsum core, similar problems are encountered with respect of the outermost ply or top liner ply exposed and not in contact with the gypsum core. For example, when a sufficient sizing effect is intended using conventional sizing agents, a great deal of sizing is necessitated and, as a result, not only the air permeability of the resulting paperboard will be lost to an extent inadequate for processing into gypsum wallboards, but also the resistance to moisture absorption, which is also a very desirable property for the finished gypsum wallboard, will not be expected. Therefore, such gypsum wallboards are met with further problems, such as the possibility of the top liner ply to peel during transportation or during secondary processing, e.g. surface finishing, and the intolerable degradation of quality by moisture absorption during storage.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to provide multi-ply paperboards useful for covering gypsum core wallboards, in which specific sizing free from the above-described technical problems encountered in the prior art is applied.
In accordance with the present invention, the multi-ply paperboard is characterized by being treated or sized at at least one of both surfaces with an organopolysiloxane comprising:
(a) from 99.95 to 85 mole % of organosiloxane units represented by the general formula
R.sup.1.sub.a SiO.sub.(4-a)/ 2 (I)
wherein R 1 is a hydrogen atom or a monovalent hydrocarbon group selected from the class consisting of methyl, ethyl, propyl, vinyl, and phenyl groups and a is 1, 2, or 3,
(b) from 0.05 to 10 mole % of mercapto-containing organosiloxane units represented by the general formula
HS--CH.sub.2).sub.p SiR.sup.2.sub.b O.sub.(3-b)/ 2 (II)
where R 2 is a hydrogen atom or a monovalent hydrocarbon group selected from the class consisting of methyl, ethyl, propyl, and phenyl groups, b is 0, 1, or 2 and p is 1, 2, 3, or 4, and
(c) from 0 to 5 mole % of methacryloxy-containing organosiloxane units represented by the general formula
H.sub.2 C═C(CH.sub.3)--CO--O--CH.sub.2).sub.q SiR.sup.3.sub.c O.sub.(3-c)/ 2 (III)
wherein R 3 is a hydrogen atom or a monovalent hydrocarbon group selected from the class consisting of methyl, ethyl, propyl, and phenyl groups, c is 0, 1, or 2 and q is 1, 2, 3, or 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The base of a paperboard to be sized with the organopolysiloxane in accordance with the present invention may be of any commercially available grades, which are prepared by blending in a suitable manner several materials, such as pulp, waste high-quality paper, newsprints, magazines, corrugated paperboards, and the like, and then subjecting the mixture to disintegration and beating, followed by a multi-ply paper making process hitherto known in the art, with addition of several known additives including sizing materials and the like. In particular, the paperboards widely used for gypsum wallboards are desirably composed of a plurality of plies, usually from 5 to 8 or even more plies, i.e, the bottom liner ply, the top liner ply, and several filler plies intermediate the bottom and top liner plies.
The organopolysiloxane as the sizing material in accordance with the present invention is composed of the organosiloxane units as represented by the general formulas (I), (II), and (III), the inclusion of the units of formula (III) being optional.
In the organosiloxane unit represented by the general formula (I), the group expressed by the symbol R 1 is a hydrogen atom or a monovalent hydrocarbon group selected from the class consisting of methyl, ethyl, propyl, vinyl, and phenyl groups, the most preferred being methyl, and a is a number of 1, 2, or 3. The mole fraction of such organosiloxane units is required to be from 99.95 to 85 mole % of all of the organosiloxane units of which the organopolysiloxane is composed. It is optional to use in combination the organosiloxane units having different values to form the component (a), preferably provided that more than 80 mole % of the component (a) are organosiloxane units having the value of a=2.
In the mercapto-containing organosiloxane units represented by the general formula (II), the group R 2 is the same as R 1 above excepting the vinyl group, the most preferred being methyl, and b is a number of 0, 1 or 2, the preferred being 0 or 1. The value of p is 1, 2, 3 or 4, the most preferred being 3 from the standpoint of easy preparation of the organopolysiloxane, although the p value has no particular influence on the quality of the product. The mole fraction of the organosiloxane units represented by the general formula (II) is in the range from 0.05 to 10 mole % of all of the organosiloxane units of which the organopolysiloxane is composed. This is because smaller amounts of the mercapto-containing organosiloxane units than 0.05 mole % will result in decreased bonding strength between the paperboards and the gypsum core, while larger amounts than 10 mole % will disadvantageously bring about decreases in the stability of the organopolysiloxane and in production cost.
The methacryloxy-containing organosiloxane units represented by the general formula (III) is optionally present in the organopolysiloxane in a mole fraction in the range up to 5 mole % of all of the organosiloxane units of which the organopolysiloxane is composed. The organosiloxane units of this type contribute to improving the bonding strength between the paperboards and the gypsum core as well as the mechanical strengths of the individual plies of the paperboards. In the formula (III), R 3 is the same as R 2 above, the most preferred being methyl, and c is preferably 0 or 1. The number of q is 1, 2, 3 or 4, the preferred being 3 for the reason of easiness in the synthetic preparation.
The molecular configuration of the organopolysiloxane may be straight chain, branched chain, cyclic, or three-dimensional network. The molecular chains may be endblocked by hydroxy groups; trialkylsilyl groups, e.g. trimethylsilyl groups; or those groups having alkoxy groups in place of the alkyl groups in the trialkylsilyl groups, e.g. dimethylmethoxysilyl groups.
The synthetic procedures for the mercaptoalkyl-containing organosilanes and the methacryloxyalkyl-containing organosilanes which correspond to the organosiloxane units (b) and (c), respectively, in the organopolysiloxane useful in the present invention are well known in the art of silicones, as disclosed, for example, in U.S. Pat. No. 3,532,729 and West German OLS No. 1,646,152.
These organosilanes are admixed with the organosiloxane composed of the organosiloxane units (a) or organosilanes corresponding to the organosiloxane units (a), and the mixture is subjected to the conventional co-gydrolysis and co-condensation, to form the organopolysiloxane of the present invention. In the preparation of the organopolysiloxanes, it is recommended to apply the known procedure of emulsion polymerization in order to produce an aqueous emulsion which is stable and advantageous for use as the sizing agent for paperboards.
Now, the method of sizing the paperboards using the above-prepared organopolysiloxane in accordance with the present invention will be described in the following.
The organopolysiloxane as the sizing agent may, needless to say, be introduced into a beater in which raw materials for making paper are blended and beated, though this method is not recommended from the standpoint of economy. An advantageous and recommendable method is the so-called surface sizing, by which the bottom surface or top surface or both bottom and top surfaces of a prepared paperboard base are coated with a liquid containing the sizing agents. The coating liquid may be a solution of the organopolysiloxane in an organic solvent but, preferably, an aqueous emulsion of the organopolysiloxane since it is economically advantageous and free from the cause of environmental pollution. The content of the organopolysiloxane in the coating liquid, usually being below a few percent or, for example, in the range from 0.5% to 3% by weight, can be adjusted as desired to obtain an optimum amount of the sizing.
The organopolysiloxane useful in the present invention can cure without the aid of any curing catalyst. However, it is optional that a certain kind of known curing catalysts, such as metal salts of organic acids, is added to the organopolysiloxane-containing coating solution in order to accelerate the curing. It is also optional to add a silane coupling agent for the purpose of improving the bonding strength of the organopolysiloxane to the paperboard texture. It is further optional to add one or more of the conventional sizing agents, such as aluminum sulfate, maleic anhydride-styrene copolymers, and the like. Alternatively, the top surface and/or the bottom surface of the paperboard base may be treated in advance with any one of these conventional sizing agents. The most economical and convenient way for obtaining the accelerated cure of the organopolysiloxane is practiced by adjusting the acidity of the aqueous slurry in the paper making process, since the curing is accelerated in proportion to acidity. The desired acidity is from pH 4.0 to pH 6.5.
The means for applying the coating liquid to the bottom or top surfaces of the paperboard base is not particularly limited, but it may include calender coating, roller coating, and spray coating hitherto known in the art. The thus coated paperboards are dried and stored in the form of roll. The curing of the organopolysiloxane on the paperboard in accordance with the present invention can be completed within one to a few days' storage to give stabilized sizing effect, compared to the case in which the cardboard is sized with a conventional epoxy-modified silicone resin, the stabilization of the sizing effect taking 10 days or even longer.
The optimum sizing amount in the above-described surface sizing of the paperboards in accordance with the present invention is determined depending, for example, on whether the paperboard is intended for use as the front cover or back cover of a gypsum core wallboard. As a general standard in the sizing of the bottom surface, however, the sizing amount is in the range from 15 g to 200 g or, preferably, from 40 g to 160 g of the organopolysiloxane per 1,000 kg of paperboard. An approximately similar range of amounts may be applied to the sizing of the top surface of the paperboard. Any smaller sizing amounts naturally give an insufficient sizing effect, while any larger amounts are considered to be disadvantageous due not only to decreases in water absorptivity and air permeability of the paperboard products but also to increases in cost of production in view of the expensive organopolysiloxane.
The following examples further illustrate the present invention by giving detailed descriptions on the preparation of mercaptoalkyl-containing organopolysiloxanes and the paperboards for gypsum wallboards sized with those organopolysiloxanes as the sizing material.
In the examples, the water absorptivity of the paperboards is expressed by the Cobb values as determined in accordance with Japanese Industrial Standard (JIS) P 8140 "Testing Method for Water Absorptivity of Paper and Paperboard (Cobb Test)", and the air permeability of the paperboards is expressed by the values as determined in accordance with JIS P 8117 "Testing Method for Air Permeability of Paper and Paperboard".
EXAMPLE 1
Into a mixture of 29 g (0.147 mole) of 3-mercaptopropyltrimethoxysilane and 320 g (4.33 moles as dimethylsiloxane units) of octamethylcyclotetrasiloxane under vigorous agitation was dropped 650 g of a 1.5% by weight aqueous solution of sodium laurylsulfate, to form a homogeneous aqueous emulsion.
The aqueous emulsion above obtained was treated with an ion exchange resin Amberlite IR121 (trademark of Rohm & Haas Co.) to convert the sodium laurylsulfate into an acid form, and then the ion exchange resin was removed. The resultant emulsion was further agitated for 70 hours at 25° C., followed by neutralization with an aqueous solution of sodium carbonate to a pH value of 6 to 7, to obtain a stable latex-like emulsion of a copolymerized organopolysiloxane containing mercaptopropyl groups. The aqueous emulsion thus obtained was diluted with water to have a solid content of about 0.7% by weight, which is hereinafter referred to as the coating liquid A.
With this coating liquid A a six-ply paperboard to be used as the front cover for a gypsum wallboard is coated at the bottom surface which had been treated by aluminum sulfate, followed by drying, to effect the surface sizing using the mercaptopropyl-containing organopolysiloxane. The sizing amount obtained was about 134 g or 70 g calculated as the organopolysiloxane per 1,000 kg of paperboard, the sizing amount having been attained by adjusting the amount of the coating liquid applied.
The thus sized paperboards were stored at room temperature and during the storage period, they were tested for water absorptivity at certain intervals of time. According to the test, it took from 30 minutes to 1 hour and from 12 hours to 20 hours for the Cobb Value to reach the upper limit of its range suitable for use in the gypsum wallboard manufacture, i.e. 0.6 g/100 cm 2 , with the above-mentioned sizing amounts of 134 g and 70 g, respectively. The sized paperboard with the sizing amount of 134 g was further subjected to storage at room temperature to undertake the Cobb Test at 24 hours' intervals, resulting to find that the Cobb value reached about 0.12 g/100 cm 2 after 2 days and then became stationary with very little variations thereafter.
For comparison, a similar sizing test was performed under the same conditions except that the sizing material was a conventional epoxy-modified organopolysiloxane (RE-29, product of Nippon Unicar Co., Japan) and the sizing amount was 150 g per 1000 kg of paperboard. The Cobb values of this comparative sized paperboard determined within 30 minutes immediately after treatment ranged from 1.2 to 1.4 g/100 cm 2 , exhibiting almost no sizing effect. It took from 5 to 10 days of curing when stored at room temperature before the Cobb value as low as 0.6 g/100 cm 2 was obtained. This value had a further, gradual lowering tendency toward a final stationary value which appeared after 15 days from the treatment. During the period, there were witnessed local variations in the Cobb value as large as 0.3 to 0.9 g/100 cm 2 .
EXAMPLE 2
A six-ply paperboard to be used as the back cover for a gypsum wallboard was surface-sized at the bottom surface which had been treated by aluminum sulfate, using the same coating liquid A as in Example 1, the sizing amount being 160 or 92 g. The Cobb value of the thus sized paperboards reached as low as 0.6 g/100 cm 2 only after 1 to 6 hours and 10 to 15 hours from the treatment for the sized paperboards with the sizing amounts of 160 g and 92 g, respectively. Stationary values were obtained after about 2 days.
For comparison, a similar sizing test was performed under the same conditions except that the sizing material was the same epoxy-modified organopolysiloxane as used in Example 1. The results showed that the Cobb value reached as low as 0.6 g/100 cm 2 after 11 to 19 days for the sized paperboard with the sizing amount of 180 g and the stabilization of the Cobb values was attained only after 1 month from the treatment.
EXAMPLE 3
Measurement of air permeability was undertaken with respect to sized paperboards of the present invention prepared in accordance with the procedure of Example 1 and also with respect to the comparative sample which was sized with the epoxy-modified organopolysiloxane as in Example 1. In this case, however, varied sizing amounts as indicated in Table I were employed, and the results of the air permeability and the Cobb values as determined after 1, 3 and 7 days from the treatment are set out in the table.
As is evident from the data in the table, the epoxy-modified organopolysiloxane necessitated a sizing amount as much as 300 g or more in order to attain practically suitable Cobb values at the sacrifice of air permeability. On the contrary, the Cobb values of the sized paperboards in accordance with the present invention could sufficiently be low even with very small sizing amounts, and this was reflected in turn on the much higher air permeability.
Table I______________________________________ Sizing Air perme- amount, ability, Cobb value, g/100 cm.sup.2 g sec. 1 day 3 days 7 days______________________________________Present 67 40 <0.6 <0.3 --invention 133 60 <0.4 <0.2 -- 130 60 -- 1-1.3 0.6-1.2 167 120 -- 1-1.3 0.6-1.2Comparison 233 250 -- 0.7-0.8 0.6-0.8 333 400 -- 0.2-0.4 <0.4______________________________________
EXAMPLE 4
A test for the manufacture of gypsum wallboards was undertaken in a commercial plant using the sized and 1-day cured paperboards of the invention prepared in Examples 1 and 2 as the front-covering and back-covering sheets, respectively, for the gypsum wallboard. The test, in which of starch was added in varied amounts to the aqueous slurry of gypsum were employed, was intended to determine the minimum amount of the starch which could be added without decreasing the bonding strength between the gypsum core and the paperboard or causing cleavages between the individual plies of the paperboard. The bonding strength was determined in accordance with the method as specified in JIS A 6901 "Gypsum Boards".
For comparison, a similar test was undertaken with paperboards sized with a conventional rosin-alum or with the paperboards prepared in Examples 1 and 2 with the epoxy-modified organopolysiloxane as the sizing material which had been cured in 3 days and 10 days, respectively.
The results of the above tests are summarized in Table II to show the minimum amounts of starch in terms of g per square meter of the finished gypsum wallboard.
Table II______________________________________Sizingmaterial Comparisonused 3-day cured 10-day curedThickness epoxy-mod- epoxy-mod-of gypsum ified ifiedwallboard, Rosin- organopoly- organopoly- Presentmm alum siloxane siloxane Invention______________________________________12 20-40* 20 18-6* 5 9 10-20* 13 18-6* 5______________________________________
In the above table, the minimum amounts marked * are not indicated in a single, definite value. This is because the starch was used in an increased amount to somewhat an excessive level to give sufficient safety factors in consideration of the rather unstable water absorptivity to be obtained when the conventional sizing material was employed. On the contrary, the data as for the present invention are indicative of the facts that the amount of starch can be remarkably reduced and that the amount of starch can be constant independently of the thickness of the gypsum wallboard.
The paperboards employed as the front-covering and back-covering sheets for the gypsum wallboard in the above tests were what had been provided with surface sizing only at the bottom surfaces, and not at the top surfaces. A further test was carried out with the paperboards which had been surface-sized at both the top and bottom surfaces in accordance with the present invention, to find that the sizing effect was much stronger compared to that obtained by the conventional sizing materials, without decreases in air permeability and with improved moisture absorption.
A further sizing effect was determined by the surface strength of the sized paperboard and, for comparison, of an unsized paperboard in accordance with JIS P 8129 "Testing Method for Surface Strength of Paper and Paperboard", in which the Denison wax sticks each having a number of from 2A to 20A to show its own adhesivity was one by one fused to the top and bottom liner surface of the paperboard and, after being permitted to cool about 15 minutes, pulled off the surface. In this case the biggest number of the wax stick which could be detached from the surface leaving no harm on the surface was taken as the "surface strength" of the paperboard. The surface strength obtained by this test is shown in Table III.
Table III______________________________________ Unsized paperboard Sized paperboard (Comparison) (Present invention)______________________________________As the front cover 6A 8A-10AAs the back cover 4A 6A-8A______________________________________
The products of gypsum wallboard manufactured with the paperboards of the present invention were found to have lesser problems of cleavage between the plies of the paperboard when subjected to secondary processing, as well as peeling of the surface paper layer during handling or transportation. In addition, the products did not exhibit such quality-wise degradation due to absorption of the atmospheric moisture as had used to occur in the conventional products even after storage for more than 30 days.
EXAMPLE 5
Coating liquids B, C and D were prepared as follows.
Coating liquid B: Into a mixture composed of 15 g (0.0894 mole) of mercaptopropylmethyldimethoxysilane, 157 g (2.12 moles as dimethylsiloxane units) of octamethylcyclotetrasiloxane and 3.5 g (0.0432 mole as trimethylsiloxy units) of hexamethyldisiloxane under agitation was dropped 325 g of a 1.5% by weight aqueous solution of sodium dodecylbenzene sulfonate, to form an aqueous emulsion. This aqueous emulsion was then treated with an ion exchange resin Amberlite IR 121 to convert the sodium dodecylbenzene sulfonate to acid form, followed by removal of the ion exchange resin. The resultant aqueous emulsion was further agitated for 40 hours at 25° C. and neutralized with a 5% aqueous solution of sodium carbonate to a pH value of 6.0, to produce a stable aqueous emulsion of an organopolysiloxane. This emulsion was diluted with water to a solid content of 1.0%.
Coating liquid C: Into a mixture of 39.9 g (0.366 mole) of mercaptopropylmethyldimethoxysilane, 9.6 g (0.076 mole as methylhydrogensiloxane units) of tetramethylcyclotetrasiloxane and 255.5 g (3.45 moles as dimethylsiloxane units) of octamethylcyclotetrasiloxane under agitation was dropped 700 g of a 1.4% aqueous solution of sodium laurylsulfate, to form an aqueous emulsion. This aqueous emulsion was subjected to treatment with an ion exchange resin as in the preparation of the coating liquid B. The resultant aqueous emulsion was further agitated for 40 hours at 25° C. to copolymerize the siloxanes, followed by neutralization with triethanolamine to a pH value of 6.5 to produce a stable aqueous emulsion of the organopolysiloxane, which was then diluted with water to a solid content of 1.0%.
Coating liquid D: Into a mixture composed of 17.6 g (0.078 mole) of mercaptoethylethylphenylmethoxysilane and 288 g (3.89 moles as dimethylsiloxane units) of octamethylcyclotetrasiloxane under agitation was dropped 700 g of a 1.4% aqueous solution of laurylsulfuric acid to form an aqueous emulsion, followed by further agitation for 10 hours at 50° C. to effect polymerization. After cooling the emulsion was neutralized by the addition of a 10% aqueous solution of sodium carbonate to a pH value of 6.5 to produce a stable aqueous emulsion of the organopolysiloxane, which was then diluted with water to a solid content of 1.0%.
The coating liquids B, C and D above prepared were employed for treating paperboards in the same manner as in Example 1. The coating amount was 70 to 90 g per 1,000 kg each. Cobb values were determined for the thus sized paperboards immediately after drying and 1 to 7 days after treatment. The results are set out in Table IV.
Table IV______________________________________ (g/100 cm.sup.2) ImmediatelyCoating after Days after treatmentliquid drying 1 2 4 7______________________________________B 0.60 0.13 0.12 0.12 0.12C 0.60 0.14 0.12 0.12 0.12D 0.60 0.15 0.13 0.13 0.12______________________________________
EXAMPLE 6
Coating liquids E and F were prepared as follows.
Coating liquid E: A mixture composed of 134 g (1.0 mole as mercaptopropylmethylsiloxane units) of tetra(mercaptopropyl)tetra-methylcyclotetrasiloxane, 740 g (10.0 moles as dimethylsiloxane units) of octamethylcyclotetrasiloxane, 232 g (0.935 mole) of methacryloxypropyltrimethoxysilane and 16 g (0.197 mole as trimethylsiloxy units) of hexamethyldisiloxane was added with 40 g of activated clay. The resulting mixture was heated with agitation at 60° C. for 8 hours. After cooling to 30° C. or below, 0.5 g of hexamethyldisilazane was added, then the activated clay was removed by filtration, and the low-boiling components were distilled off by heating at 110° C. under a reduced pressure of 10 mmHg, to produce a clear, colorless and oily liquid.
To 300 g of the oily liquid thus obtained were added 695 g of water and 5 g of Newcol 512 (tradename of Japan Emulsifiers Co. Ltd.), an emulsifier expressed by the formula C 9 H 19 --C 6 H 4 --OC 2 H 4 ) 12 OH. The mixture was vigorously agitated to form a stable aqueous emulsion, which was then diluted with water to a solid content of 1.0%.
Coating liquid F: A mixture of 25 g (0.186 mole) of mercaptopropylmethyldimethoxysilane, 9 g (0.036 mole) of methacryloxypropylmethyldimethoxysilane, 260 g (3.52 moles as dimethylsiloxane units) of octamethylcyclotetrasiloxane and 16.2 g (0.20 mole as trimethylsiloxy units) of hexamethyldisiloxane was added with 690 g of a 1% aqueous solution of sodium laurylsulfate and emulsified with agitation. The aqueous emulsion thus obtained was treated with an ion exchange resin in the same manner as in Example 5, followed by further agitation for 70 hours at 25° C. and subsequent neutralization by the addition of a 5% aqueous solution of sodium carbonate to a pH value of 6.5, to produce a stable aqueous emulsion of the organopolysiloxane, which was then diluted with water to a solid content of 1.0%.
The coating liquids E and F above prepared were used to size the paperboards in the same manner as in Example 1, the sizing amount being 70 to 90 g/1,000 kg. The Cobb values of the thus sized paperboards were determined immediately after drying and 1 to 7 days after the treatment, with the results as set out in Table V.
Table V______________________________________ (g/100 cm.sup.2)Coating Immediately Days after treatmentliquid after drying 1 2 4 7______________________________________E 0.60 0.12 0.12 0.12 0.12F 0.60 0.12 0.12 0.12 0.12______________________________________
A gypsum wallboard was manufactured with the paperboards sized with the coating liquids E and F as the front-covering and the back-covering sheets in the same manner as in Example 4, to attain very satisfactory results just the same as in that example.
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Novel and improved paperboards useful for making gypsum wallboards, which are sized with a specific organopolysiloxane comprising mercaptoalkyl containing organosiloxane units and, optionally, methacryloxy-containing organosiloxane units in its molecular structure. The sizing compound is used in a relatively small amount and yet can exhibit an excellent effect within a very short time. The sized paperboards have adequately controllable moisture absorption as well as air permeability. They are used to cover or sandwitch a gypsum core to form a complete wallboard in a convenient and economical manner.
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FIELD OF THE INVENTION
The present invention concerns a horizontal magnetic head with a Hall effect and its embodiment method. In particular, it is applicable to the reading of a recording on a magnetic medium, but also to writing on such a medium.
BACKGROUND OF THE INVENTION
The structure of a reading and writing horizontal head for longitudinal recording is shown on FIG. 1. Various films (whose relative dimensions have not been observed in order to provide more clarity) are deposited and engraved in a semiconductive substrate 10 so as to form a magnetic circuit 12 with an airgap filled up by a nonmagnetic spacer 14 and a conductive winding 16. This winding 16 includes two sets of windings interconnected by a link 18; each set is wound around one magnetic pillar 20, 21. These magnetic pillars 20, 21 connect the first and second horizontal polar pieces 22, 23 of the circuit 12.
The winding 16 is connected at its two extremities by means of links 24, 26 traversing the substrate 10 to contact blocks 28, 30 disposed on the lower face of the substrate.
The track to be written and/or read 32 runs off above the airgap.
Various embodiments of such heads are described in the European patents EP-A-152 326 and EP-A-262 028.
Compared with this known thin film technology, another technique has been developed using the characteristics of materials with the Hall effect. Such materials make it possible to embody reading heads for extremely narrow recording tracks.
The document FR 2 518 792 describes a vertical magnetic head using a Hall effect sensor. Such a magnetic head is diagrammatically shown on FIG. 2. As can be observed on this figure, the Hall effect sensor 34 is disposed in a space situated between two polar pieces 36, 38. These polar pieces 36, 38 are placed vertically with respect to the magnetic recording medium 32 and are separated at the level of the section of the head close to the medium by a nonmagnetic spacer 40.
Such a magnetic head only comprises a single Hall effect sensor; it is thus subjected to thermal or electronic drifts, these drifts needing to be made up for.
FIG. 3 diagrammatically represents another known vertical magnetic head and comprising a Hall effect sensor. This magnetic head is described in detail in the document U.S. Pat. No. 3,800,193.
The polar pieces 36, 38 join up at each of their extremities. They are firstly separated by a nonmagnetic spacer 40 at the section of the polar pieces opposite the magnetic recording medium 32, and secondly by the Hall effect sensor 34.
This magnetic head exhibits the same drawbacks as the previous one.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a horizontal magnetic head which includes at least one Hall effect sensor and which makes it possible to mitigate these drift problems by means of a simple differential measurement.
More specifically, the present invention concerns a horizontal magnetic head with the Hall effect and including contained in a recess formed in a semiconductive substrate a first horizontal polar piece, a second horizontal polar piece divided into two sections by a nonmagnetic spacer, a first magnetic pillar connecting the first polar piece to one section of the second polar piece, a second magnetic pillar connecting the first polar piece to the other section of the second polar piece, wherein at least one of the pillars comprises a Hall effect sensor. The position of the sensors in the upper part of the pillars is indifferent as regards functioning of the head.
The magnetic head of the invention is horizontal: they comprise two magnetic pillars, each able to integrate a Hall effect sensor. The presence of two sensors makes it possible to simply carry out a differential measurement of the read signals of a recorded magnetic medium delivered by each sensor and to obtain a drift-free signal. In addition, this signal has double the intensity of the signal delivered by a single sensor.
Advantageously, in the case when each pillar comprises a Hall effect sensor, these sensors are connected by outputs to the inputs of a differential circuit delivering a reading signal on one output.
The invention also has another advantage: it is possible to integrate on a single head both the reading means (whose Hall effect sensor(s) form a part of these means) and writing means, these reading and writing means making use of the same magnetic circuit. In this case, the magnetic head of the invention further includes a conductive winding surrounding the two magnetic pillars.
The object of the invention is to also provide a method to implement the head described above. According to this method, inside a recess formed in a semiconductor substrate:
the first horizontal polar piece is formed,
a first nonconducting film is deposited,
four conductive blocks are formed close to at least one of the extremities of the first horizontal polar piece, these blocks being able to be connected to the outside of the substrate,
a second nonconducting film is deposited on the unit,
in the nonconducting films unit, two openings are engraved reaching the extremities of the first horizontal polar piece,
these openings are filled with a magnetic material so as to constitute two magnetic half-pillars trimming flush the surface of the second nonconducting film,
a third nonconducting film is deposited on the unit,
in the second and third nonconducting films, openings reaching the conductive blocks are engraved,
a film of a material with the Hall effect is deposited on the unit,
this material film with the Hall effect is engraved so as to define the shape of each of the Hall effect sensors,
a fourth nonconducting film is deposited on the unit,
two magnetic half-pillars are embodied embedded in a fifth nonconducting film, these half-pillars being situated plumb with the already formed half-pillars,
the second magnetic horizontal polar piece is embodied embedded in a sixth nonconducting film.
so as to embody a reading and writing head, a conductive winding is further constituted surrounding the two magnetic pillars during the stage for embodying the conductive blocks.
The conductive blocks and the extremities of the winding (in the case of a reading/writing head) are connected by metal links to the outside of the substrate. These metal links are conventionally obtained, either by engraving of the rear face of the substrate and the first nonconducting film and metallization of the holes engraved, for example, prior to the stage for forming the conductive blocks, or by engraving the front face of the sixth, fifth and fourth nonconducting films and metallization of the engraved holes at the end of the manufacturing process.
BRIEF DESCRIPTION OF THE DRAWINGS
The characteristics and advantages of the invention shall appear more readily from a reading of the following description of embodiment examples, given by way of explanation and being in no way restrictive, with reference to the accompanying drawings in which:
FIG. 1, already described, diagrammatically shows a horizontal magnetic head according to the prior art,
FIG. 2, already described, diagrammatically shows the Hall effect magnetic head according to the prior art,
FIG. 3, already described and relating to the prior art, diagrammatically shows another Hall effect magnetic head,
FIG. 4 shows a first stage of a method for embodying the head of the invention,
FIG. 5 shows a second stage of this method,
FIG. 6 diagrammatically and partially represents a top view of the device after the second stage,
FIG. 7 diagrammatically represents a third stage of this method,
FIG. 8 shows a fourth stage of this method,
FIG. 9 diagrammatically represents a top view of a Hall effect sensor,
FIG. 10 diagrammatically represents a fifth stage of the method,
FIG. 11 diagrammatically represents a cutaway view of the Hall effect magnetic head conforming to the invention,
FIG. 12a shows the circulation of the magnetic field lines inside the magnetic circuit, and
FIG. 12b diagrammatically represents the Hall effect sensors connected to a differential circuit in accordance with one embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 4 shows a cutaway view of a semiconductive substrate made, for example, of silicon, in which a recess has been engraved. As described in the document EP-A-O 262 028, a horizontal magnetic film is made to increase at the bottom of this recess by means of electrolysis, this film being an FeNi film forming a first polar piece of the magnetic circuit.
The first polar piece 42 is coated with a nonconducting film 44 made of SiO 2 , for example.
The next stages of the method for embodying a magnetic head conforming to the invention are described with reference to FIG. 5 which shows one section of the head.
Close to and preferably around each extremity of the first polar piece 42, four conductive blocks (only the blocks 46, 48 and 54, 56 are shown on the section) are deposited on the first nonconducting film 44, these blocks being surrounded with the windings of a conductive winding. This winding is formed of two sets of interconnected windings 62a and 62b.
The unit is coated with a second nonconducting film 64 made of SiO 2 , for example, which is conventionally selectively engraved so as to form openings opposite the extremities of the first polar piece. These openings are filled by an electrolytic deposit so as to form two magnetic half-pillars 66, 68 made of FeNi trimming flush the surface of the second nonconducting film 64.
The unit is coated with a nonconducting film 70 made of SiO 2 with a thickness X being preferably slight, such as 0.2 micrometers.
FIG. 6 shows a partial top view of the device after carrying out the previously described operations. This figure shows that the half-pillar 66 is surrounded by the conductive blocks 46, 48, 50, 52 and that the half-pillar 68 is surrounded by the conductive blocks 54, 56, 58 and 60.
The blocks 48 and 54 inside the magnetic circuit have an elongated strip shape so as to allow for a taking of contact without having to traverse the first polar piece 42, as shall be seen subsequently.
Each series 62a and 62b of the winding comprises about ten windings, for example.
FIG. 7 shows the result of the following stages of the embodiment method concerning one cutaway view. By means of photolithography and engraving, openings are made in the nonconducting films 64 and 70. These openings reach the conductive blocks 46, 48, 50, 52, 54, 56, 58 and 60.
A Hall effect material film, made of InSb, for example, with a thickness Y equal to about 1 micrometer is disposed on the unit. This deposit is carried out by cathodic evaporation.
The shape of the sensors is defined by photolithography or engraving. FIG. 7 shows the resin mask 74, 76 making it possible to define the shape of the sensors at the time of engraving.
FIG. 8 diagrammatically shows the result of the following stages of the embodiment method. The sensors 78 and 80 are engraved so as to be integrated into the magnetic pillars. They are connected to the conductive blocks on both sides of the half-pillars 66 and 68.
A fourth nonconducting film 82 made of SiO 2 with a thickness Z equal to 0.2 micrometers plumb with the sensors is deposited on the unit.
FIG. 9 diagrammatically shows a top view of a Hall effect sensor integrated in a magnetic pillar.
The sensor 78 shown has dimensions roughly larger than the section of the half-pillar 66. The sensor 78 is further provided with projecting flaps 84, 86, 88 and 90 for the contacts with the conductive blocks 46, 52, 48 and 50 respectively.
FIG. 10 diagrammatically illustrates the result of the next stages of the method. The upper half-pillars 92 and 94 are embodied plumb with the half-pillars 66 and 68 respectively. The half-pillars are made of FeNi, for example.
These half-pillars 92 and 94 are embodied in the openings made in the fifth nonconducting SiO 2 film 92 firstly deposited on the unit, either by cathodic evaporation of FeNi in this fifth film and surfacing, or by electrolysis.
In this latter case, firstly on the fifth nonconductive film provided with these openings, a conductive material is deposited by cathodic evaporation and then the selected magnetic material is electrolyzed by using the conductive material as an electrode, and finally the unit is surfaced or refined so as to form the pillars.
The overall height L of the pillars is equal to 10 micrometers.
FIG. 11 diagrammatically represents a section of a magnetic head conforming to the invention at the end of the embodiment method.
An upper polar piece made of FeNi and separated into two sections 98 and 100 by a nonmagnetic spacer 102 is embodied in accordance with the technique described in the document EP-A-O 262 028 (FIGS. 5j, 5k, 51 and 5m).
FIG. 11 shows that the substrate 10 and the first nonconducting film 44 are pierced with openings (only two, namely 104 and 106, are shown on the cutaway view) allowing for access to the conductive blocks via behind the magnetic head. These openings enable the sensors 78 and 80 to be conventionally connected to firstly processing means, such as a differential circuit, and secondly to an electric power circuit.
Other openings 105a and 105b are pierced so as to allow for the embodiment of links between the winding and the feed means (not shown). One embodiment of these links is described in the document entitled "Electrical connection through silicon wafers" which appeared in the Journal of the Electrochemical Society - Fall Meeting, Chicago, 9 to 14 Oct. 1988.
The Hall effect sensors are only used for reading a magnetic signal recorded on a medium running off parallel to the second horizontal polar piece.
As shown on FIG. 12a, the magnetic field lines B derived from the signal are contained inside the magnetic circuit (formed by the polar pieces and the pillars) by traversing the sensors 78 and 80 in opposing directions.
As shown in FIG. 12b, the sensors 78 and 80 are fed with current by current generators 108 and 110 respectively connected to the blocks 50 and 58. The blocks 52 and 60 are grounded.
The Hall voltage due to the crossing of the sensors by the magnetic field lines B is measured between the blocks 46 and 48 for the sensor 78, and 54 and 56 for the sensor 80. These voltages each include a Hall component due to the sensors being crossed by the magnetic field lines.
The voltages also include a component due to the noise added to the Hall component of one of the sensors and which is entrenched in the Hall component of the other of the sensors.
The Hall voltage delivered by the sensor 80 is applied to the input (+) of a differential circuit 112. The Hall voltage delivered by the sensor 78 is applied to the inputs (-) of this circuit 112. This circuit delivers an output signal VS having, not only a double amplitude of the signals delivered by each sensor, but also freed of any noise and in particular of any thermic or other form of drift eliminated at the time of differentiation. These Hall components are also of opposing signs.
The Hall effect magnetic head of the invention thus makes it possible to obtain a high amplitude reading signal freed from noise due to drifts. By way of example, this head has the following characteristics:
Sensitivity to a magnetic field of thin-layered Hall effect sensors: about 40 mV/mA.kGauss.
Amplitude of the field traversing the secondary airgaps formed at the level of the Hall effect sensors: about ±10 Gauss (with a typical polarization of the sensors of 2 mA).
Hall voltage collected at the terminals of a sensor: about 1.4 mVpp.
Amplitude of the reading signal after differentiation Vs: about 2.8 mVpp.
This latter figure represents a gain of about 20 with respect to the inductive heads using a reading winding. In addition, when the head is used for writing, the invention uses a winding, preferably with a small number of revolutions (for example, 10) so as to obtain a reduced magnetic circuit in order to compensate for the efficiency losses of the head on writing due to the secondary airgaps in the pillars so as to incorporate the Hall effect sensors.
It goes without saying that the invention is not merely restricted to the described embodiment example; on the other hand, the invention is applicable to all variants. In particular, in the embodiment example referred to above, the Hall effect magnetic head is able to be used for reading, but also for writing by virtue of the winding 62a, 62b. So as to obtain solely one reading head, it merely suffices to omit incorporating this winding when embodying the method.
Moreover, the deposits of the various magnetic materials in this case are electrolytic deposits, but it is possible to use any other type of deposit.
Finally, the device of the invention comprises two Hall effect sensors (one in each pillar), but a device comprising only one Hall effect sensor integrated in one of the two pillars may come within the context of the present invention.
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Horizontal magnetic head with Hall effect and including a magnetic circuit composed of a first horizontal polar piece (42) and a second horizontal polar piece (98, 100) separated into two sections by a nonmagnetic spacer (102), two magnetic pillars, each connecting the sections (98, 100) of the second polar piece to one extremity of the first polar piece (42).
According to the invention, at least one of the pillars comprises a sensor with an integrated Hall effect (78, 80).
Application for magnetic recording reading and writing.
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BACKGROUND OF THE INVENTION
The present invention relates to spray guns for spraying liquids such as paint or the like, and in particular to a spray gun assembly including a paint supply container having motor driven agitator means for automatically mixing the paint in the container.
In the spraying of paints and other suspensions by means of a spray gun assembly including a spray gun and an associated paint supply container, it is desirable to provide agitation of the paint in the supply container to prevent suspended pigments from settling to the bottom of the container and to produce optimum distribution of pigment in the vehicle. It will be obvious that in the spraying of various liquids other than paint, it is often necessary to provide for agitation in the supply container to effect proper mixing of the various components of the liquid to be sprayed.
Prior attempts to agitate paint within a supply container include the provision of movable agitator members inside of the container, whereby upon manual shaking of the container the agitator members move about within the container and produce mixing of the contents therein. However, such an expedient is subject to the disadvantage that it is not automatic, and thus repeated manual shaking of the container is required to maintain thorough mixing.
Another type of prior agitator for a paint supply container of a spray gun having a manually operable trigger mechanism is described in U.S. Pat. No. 3,412,937. As taught therein, an agitator member is disposed within the paint supply container and secured to an agitator rod which projects outwardly of the container. The rod is engageable by the spray gun trigger mechanism for actuation thereby, whereby each time an operator squeezes the trigger to produce a spray of paint, the resulting movement of the trigger automatically imparts movement to the agitator within the container to effect mixing of the paint supply. A disadvantage of such an arrangement, however, is that if the spray gun assembly is allowed to sit idle for a period of time, and unless the gun is triggered relatively frequently, pigment tends to settle in the bottom of the container.
Yet another contemplated agitator comprises a rotary impeller disposed in the paint supply container and driven by motor means. Although such agitators operate relatively continuously and maintain agitation of the paint, the mixing obtained with rotary impellers has been less than satisfactory.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a paint spray gun assembly including a supply container having an effective agitator for automatically and substantially continuously effecting mixture of the contents of the container.
Another object of the invention is to provide such an agitator which includes a substantially flat paddle extended into the container and reciprocable therein in directions generally perpendicular to the plane in which it lies.
A further object of the invention is to provide such an agitator wherein the paddle is coupled with an air motor for being reciprocated continuously and for as long as air is provided to the motor.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided, in combination with a spray gun assembly of the type including a hand operated spray gun and an associated supply container, an agitating mechanism for mixing the contents of the supply container. The agitating mechanism includes an agitator carrying member one end of which extends into the interior of said container; an agitator paddle disposed interiorly of said container and mounted on said one end of said carrying member; and motor means connected with an opposite end of said carrying member for reciprocating said carrying member and thereby said paddle along a linear path, whereby said paddle agitates contents of said container.
In a preferred embodiment said agitator paddle is generally flat and planar and is reciprocated along a path generally perpendicular to the plane thereof, said motor means comprises an air motor, and said supply container is provided with a top closure member and said motor means is mounted on said closure within said container.
The foregoing and other objects, advantages and features of the invention will become apparent upon a consideration of the following detailed description, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of a spray gun assembly including a fluid supply container, embodying an agitator mechanism constructed in accordance with the present invention,
FIG. 2 is a cross-sectional side elevation view of the supply container and agitator mechanism, showing the structural details of an air motor of the agitator mechanism;
FIG. 3 is a cross-sectional side elevation view of the supply container and agitator mechanism, taken substantially at right angles to the view of FIG. 2, and shows additional structural details of the air motor, and
FIG. 4 is a plan view taken along the lines 4--4 of FIG. 3, and shows the configuration of an agitator paddle of the agitator mechanism.
DETAILED DESCRIPTION
Referring to the drawings which illustrate salient features of a preferred embodiment of the invention, and in particular to FIG. 1, a paint spray gun assembly 20 includes a spray gun 22, a paint supply container 24 and a top closure member or lid 26 which substantially seals the upper end of the supply container. The spray gun includes a handle 28 having an air inlet 30 for receiving air under pressure through a supply line 32, and an outlet nozzle 34 for emitting a paint spray, the paint being drawn up from the container to the nozzle through a syphon tube 36 having a lower extension 36' which projects down into the container adjacent the bottom thereof. The spray gun 22 further includes a valve means 38 movable between open and closed positions to control the flow of pressurized air through the device, valve means 40 movable between open and closed positions to control the flow of paint through the nozzle 34 and a manually operable trigger 42 for controlling operation of the valves 38 and 40. The trigger is pivotally mounted at its upper end by a pivot pin 44, and is movable between a closed or inoperative position away from the handle 28 and an open or operative position toward the handle. The valves 38 and 40 are normally biased to closed position and the trigger is biased thereby to the inoperative position, and the trigger may be manually squeezed by an operator to move the valves to open position. The cover 26 has a seal 46 for sealing with an upper rim of the container, the container is held beneath the cover by a yoke 48 and, although not shown, it is understood that a relatively small vent hole is formed through the cover to permit entry of air into the container as paint is removed therefrom.
Referring in particular to FIGS. 2-4, the agitator mechanism of the invention includes an agitator carrying member or rod 50 having a relatively flat agitator paddle 52 mounted on its lower end by means of a screw 54 and connected at its upper end to a motor means, indicated generally at 56. The motor means reciprocates the rod in directions along its length, thereby reciprocating the paddle in directions perpendicular to the plane in which it lies and agitating the paint supply in the container 24 to produce a homogeneous suspension of the pigment in the vehicle. As will be described, the agitation is entirely automatic and substantially continuous, and yet is produced by a relatively simple and inexpensive mechanism.
In the disclosed embodiment the motor means 56 comprises an air motor including a generally cylindrical outer housing 58 having formed therewithin a cylindrical cylinder 60, an air inlet passage 62 and an air outlet passage 64. The housing is mounted on the lower side of the container lid 26 by means of an air inlet fitting 66 and an air outlet fitting 68, and is sealed with the lid by a seal 70. The air inlet fitting communicates with the air inlet passage and the air outlet fitting with the air outlet passage so that, as will be described, air under pressure may be introduced through the air inlet fitting and exhausted through the air outlet fitting to operate the motor and reciprocate the paddle 52 within the container.
A piston 72 within the cylinder 60 is slidingly sealed therewith by an annular seal 74. A valve member 76 having a passage 78 longitudinally therethrough is received and secured within the piston centrally thereof, such that an upper end of the valve member projects slightly above the upper surface of the piston. A lower end of the valve member connects with a cylindrical piston rod 80 having a chamber 82 formed therewithin in communication with the passage 78, and a lower end of the piston rod defines a threaded stud and is threadably engaged with an upper end of the agitator rod 50. The piston rod is slidingly sealed with a lower end of the housing 58 by a seal 84, and a flexible bellows 86 is connected to and about the lower end of the housing by a threaded ring 88 and to and about the juncture between the piston rod and the agitator rod by means of being captured therebetween.
The piston has a pair of passages 90 and 92 formed longitudinally therethrough, and a spool valve is associated with the piston and the valve member 76. The spool valve includes an upper plate 94 and a lower plate 96 interconnected by a pair of posts 98 and 100, and the posts extend through respective ones of the piston passages 90 and 92. The piston passages are of larger diameter than the posts, and the lengths of the posts are such that when the spool valve is in an upward position with respect to the piston the lower plate 96 is against the lower surface of the piston and seals the piston passages 90 and 92 and the upper plate 94 is elevated above the valve member 76 and opens the passage 78, and when the spool valve is in a downward position with respect to the piston the lower plate 96 is away from the lower surface of the piston and opens the piston passages 90 and 92 and the upper plate 94 is against the upper end of the valve member and closes the passage 78. A tapered coil spring 102 on the lower surface of the cover 26 within the cylinder 60 engages the upper plate 94 when the spool valve and piston are in an uppermost position, and a cylindrical coil spring 104 rests on a lower surface of the housing 58 around the piston rod 80 and engages the lower plate 96 when the spool valve and piston are in a lowermost position. A passage 106 extends through the piston rod between the chamber 82 and a chamber 108 between the piston rod and the bellows 86, the air inlet passage 62 opens into a space 110 between the piston rod and the housing above the seal 84, and the air outlet passage 64 communicates with the chamber 108.
A hose 112 between the air inlet 30 to the spray gun 22 and the air inlet fitting 66 of the motor means 56 connects air under pressure to the fitting. Under this condition, and with the piston 72 and spool valve in their lowermost position as shown in the drawings, such that the lower plate 96 of the spool valve is against the lower surface of the piston to seal the piston passages 90 and 92, air flowing through the air inlet passage 62 enters the space 110 between the piston rod and housing 58 and flows into the cylinder 60 on the lower side of the piston. This causes the plate 96 to be held against the piston and the piston to be moved in the upward direction, thereby moving the agitator paddle 52 in the upward direction. At the same time, air in the cylinder above the piston is exhausted through the passage 78, the chamber 82, the passage 106, the chamber 108 and the air outlet passage 64 for venting to atmosphere through the air outlet fitting 68.
When the piston and spool valve reach their uppermost position, the upper plate 94 of the spool valve engages the spring 102 which impedes further upward movement thereof so that, as the piston continues to rise, the spool valve moves downwardly relative to the piston. The upper plate 94 then seats against the upper end of the valve member 76 to seal the passage 78, and the lower plate 96 moves away from the lower surface of the piston to open the piston passages 90 and 92, whereby communication is provided between the portions of the cylinder 60 above and below the piston to equalize the air pressures therein. When this occurs, and since the lower portion of the piston rod 80 is exposed to air at atmospheric pressure and the upper portion to the pressure of air in the cylinder, an imbalance of forces exists which moves the spool valve and piston in the downward direction with the upper plate 94 being held against the upper surface of the valve member and sealing the passage therethrough, thereby moving the agitator paddle 52 in the downward direction.
When the spool valve and piston move downward to a point whereat the lower plate 96 of the spool valve again engages the coil spring 104, with continued downward movement of the piston the spool valve is moved upwardly relative to the piston. The lower plate 96 then engages the lower surface of the piston to seal the piston passages 90 and 92 and the upper plate 94 moves above the upper end of the valve member 76 to open the passage 78, whereupon the described cycle of operation is repeated.
Thus, upon application of air under pressure at the inlet fitting 66 the motor means 56 operates to reciprocate the agitator paddle 52 within the paint supply container 24 in directions perpendicular to the plane in which the agitator paddle lies, thereby thoroughly agitating the paint supply in the container and producing a homogeneous suspension of the pigment in the paint. Agitation is entirely automatic and continuous for so long as air is applied to the inlet fitting, and as compared with agitators of the rotary type, or of the type requiring mechanical shaking or implemented only upon actuation of the spray gun, provides significantly improved mixing of the paint.
While one embodiment of the invention has been described in detail, various modifications and other embodiments thereof may be devised by one skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims.
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An improved spray gun assembly includes a fluid supply container connected to a spray gun and a manually operable trigger for actuating the spray gun, in combination with a motor driven agitator for automatically agitating the fluid contents of the supply container. The agitator is driven by an air motor, and comprises a paddle which is reciprocated in the fluid contents in directions perpendicular to the plane in which it lies.
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BACKGROUND OF THE INVENTION
1. Field of the Invention.
This invention relates, in general, to a prefabricated door frame kit designed for easy shipping, handling, storage, and installation. More specifically, this invention relates to prefabricated door frames constructed to self-align to fit out-of-plumb walls, warped doors, or varying wall thicknesses, while minimizing separation of joints.
2. Description of the Related Art.
Prefabricated door assemblies have been built in order to eliminate the need for skilled craftsmen to custom-build door frame and door systems at construction sites. Unitary construction of these prefabricated door assemblies has proved cumbersome, inefficient to ship, and difficult to install into imperfect roughed-in framing. Sklar (U.S. Pat. Nos. 3,250,049 and 3,338,008) and J. H. Parker (U.S. Pat. No. 3,239,978) disclose knock-down prefabricated door assemblies, which are relatively easy to transport to construction sites and which fit into openings that vary somewhat in size and shape. McKann (U.S. Pat. No. 5,345,722) discloses a plastic door frame, with first and second inside sections having a frictionally-engaging slot and tongue system for adjustment to varying wall thicknesses. Winston (U.S. Pat. No. 5,365,708) discloses jambs comprising two members, having L-shaped shoulders, which fit together to allow expansion of the jamb width.
G.L. Barr (U.S. Pat. No. 4,166,346) adds to a prefabricated door assembly refinements intended to maintain the tightness and integrity of the joints and of the connection of the door assembly to the door frame. Barr discloses tongue and groove connection of casings to jambs, and a connection between side and head jambs that provides an outward-biasing of the side jambs.
What is still needed is a prefabricated door frame assembly designed for easy installation that results in high quality appearance and tight-fitting joints, in spite of imperfections and irregularities in the rough-framing, jambs, or door.
SUMMARY OF THE INVENTION
It is the general object of the present invention to provide a prefabricated door assembly which is conveniently and inexpensively shipped and installed, which stays securely in place, and which retains the integrity of its connecting joints.
It is a particular object of the present invention to provide an expandable connection between the casings and jambs. This is preferably done by a tongue and groove connection of casings to the jambs and by the provision of a plurality of pins protruding from the tongues of the casings that are specially formed to engage the grooves provided in the jambs. These pins allow the casings to be adequately connected to the jambs for convenient shipping, storage, and installation. The connection is, however, loose enough to allow some movement of the casing during final positioning to conform to irregularities in the door opening and surrounding walls.
It is a further object of the present invention to include within the prefabricated door assembly two brackets which will connect the ends of the head jamb to the side jambs and maintain these connections throughout the useful life of the door assembly.
The invented door assembly may be put into a compact kit form, for efficient display and a self-contained product for do-it-your-selfers. The prefabricated door assembly and kit set forth in this invention may also contain hardware, for example, hinges or a means for providing and maintaining pressure between each jamb and its adjacent portion of door opening, that is, shims or shimming hardware.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodiment of the door assembly invention, assembled.
FIG. 2 is an exploded fragmentary perspective view of an upper corner of the door assembly invention of the embodiment of FIG. 1.
FIG. 3a is a cross-sectional end view of a jamb and casing of FIG. 2, with door stop attached to the jamb and pins included in the tongue and groove connection of the casings.
FIG. 3b is a cross-sectional end view of the embodiment of FIG. 3a, shown with the casing connections expanded.
FIG. 4 is a view of the back of a side casing and head casing according to one embodiment of the door assembly invention, showing the pins protruding from the casing tongues.
FIG. 5 is a perspective view of one embodiment of the door assembly kit according to the invention, including end-caps.
FIG. 6 is a cross-sectional view of the embodiment of FIG. 5, viewed along the lines 6--6.
FIG. 7 is a cross-sectional view of the embodiment of FIG. 5, viewed along the lines 7--7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It will be seen in FIG. 1 that the door assembly 10 is comprised of three basic parts--a pair of vertically upstanding side units and a horizontal header unit spanning the upper ends of the side units. The side units comprises side jambs, herein also called "vertical jambs" 12, which may be manufactured in any desirable length, for example, to fit the common 811/2-82 inch roughed-in door openings. It is also contemplated that the foot ends of vertical jambs 12, side casings 16, and door stop 18 may be trimmed or cut to length at the construction site. The header unit comprises a horizontal or head jamb 14 and head casings 16'. Vertical jambs 12 and head jamb 14 are each of one-piece construction.
As shown in FIG. 2, the narrow, side edges 20, also called longitudinal edges, of each vertical jamb 12 and head jamb 14 contain longitudinal grooves 22 extending their entire length. These grooves 22 are sized to receive tongue 24 projecting transverse the body 23 of casing 16, 16'. Preferably, tongue 24 is slightly tapered to make its outer end slightly narrower than its connection to the casing body 23. Also, the walls of the groove 22 are slightly tapered so that the inner end of the groove is slightly narrower than the groove-opening. This tapering of tongue and groove allows for a good fit in spite of wood irregularities and swelling. Casing 16, 16' illustrates one of many possible alternative casing styles including the tongue 24 extending approximately perpendicularly from the body 23. The preferred casing 16, 16' is economical to manufacture and is simple and sturdy.
Head jamb 14 has a notch 15 cut on the underside of each end 17 transverse its length. Notch 15 is intended to rest upon the top end 19 of vertical jamb 12, and, by means of bracket 28, to engage the jamb top end 19.
Bracket 28 is a generally L-shaped member, with one leg attached to the head jamb 14 and the other leg extending down along the side of the top end 19 of the vertical jamb 12. Screws, nails, or other means secure the bracket 28 to the head jamb 14, while a friction fit of the vertical jamb 12 in between the bracket 28 and the notch 15 of the head jamb 14 connects the vertical jamb 12 to the head jamb 14. Bracket 28 is preferably constructed of plastic sturdy enough to sustain the desired 90° joint of vertical jamb 12 and head jamb 14 during the useful life of the door assembly, but is flexible enough to allow slight variations from the perfect 90° angle which are likely to occur in actual placement and installation. This flexible bracket 28, therefore, is an important means for providing a tight and close joint between the vertical jambs 12 and head jamb 14 while adjusting the joint to an imperfect roughed-in frame.
FIGS. 3a and 3b show end cross-sectional views of a vertical jamb 12, casing 16, and attached door stop 18. Of special interest is pin 32 of approximately 3/4 inch length embedded in the tongue 24 of the casing 16. This pin 32 engages the groove 22 of the jamb 12 securely enough to hold the casing in position, as shown in FIG. 3a, during storage, transport, and handling at the construction site. However, the pin 32 is loose enough to allow self-aligning of the casings 16 during installation in the roughed-in door opening during final installation.
By "self-aligning" is meant that, when the side assemblies or head assembly are installed in the roughed-in frame opening, the casings 16, 16' automatically move out from the jambs 12 in response to the force exerted on the casings by the irregularities of the roughed-in frame. That is, if the roughed-in framing is not perfectly in plumb or the framing and surrounding walls are not perfectly in plumb and a consistent thickness, the casings or part of the length of the casings will move out from the jamb to become distanced from the side edges 20 of the jamb 12, as shown in FIG. 3b. Preferably, the pin 32 does not come completely out of its hole in the groove 22 and preferably the casing tongue 24 does not come completely out of the groove 22, so that a connection between casing and jamb is maintained for strength until final nailing of the casing to the roughed-in frame and for a desirable appearance without gaps between casing and jamb. The preferred tongue 24 and groove 22 are 1/4 " long, and the total expansion of the two casings is preferably up to about 3/8 ", that is, about 3/16 " on each side. Alternatively, smaller or larger tongue and grooves may be used, for example, 1/2 " tongue and groove and up to a total expansion of 7/8 ", that is, about 7/16 " on each side. In the same manner as here described for the vertical jamb 12 and vertical casings 16, pins 32 embedded in the tongue 24 of head casing 16' also allow self-alignment of the head casings 16' relative to the head jamb 14.
Thus, the pin 32 and tongue and groove system are a preferred embodiment of an expandable connection means for connecting casings to jambs, so that the casing may expand away from the jamb to selfalign during installation. This expandable connection makes installation easy even for a non-skilled installer, because the casings stay on the jambs and adjust to fit framing irregularities without any significant manipulation or adjustment by the installer.
FIG. 4 shows the underside of side (vertical) and head (horizontal) casings 16, 16', with a plurality of pins 32 protruding from the tongue 24 of the casings 16, 16'. The side casing 16 is mitered on one end 42, and the head casing 16' is mitered on both ends 44, 44'. The mitered ends are those which, in final position, will be at one top corner of the door assembly 10.
A typical 831/2 inch casing intended for vertical installation is preferably provided with 2-7 pins, and preferably 5 pins are used. The spacing (S) of the pins is preferably approximately even, preferably 17-21 inches, and no pin is positioned a distance (D) closer than 2 inches from either end 42, 42 of the casing 16.
A typical horizontal, head casing may be provided with 2-3 pins. Preferably, for a head casing up to about 2 feet, 4 inches in length, 2 pins are used. Preferably, for a head casing longer than 2 feet, 4 inches, 3 pins are used. The pins are spaced approximately 17-21 inches from each other, and no pin is positioned a distance (D) closer than 2 inches from either end 44, 44'.
Preferably, the pins 32 are pin nails, such as are used with air guns, which typically consist of an elongated shaft and only a very slight enlargement on one end of the shaft for a head. The preferred pin nail for pine or other soft wood is 3/4 inches long, so that about 1/2 inch of the pin nail protrudes from the tongue 24 to enter the wood of the groove 22. Alternatively, a 1 inch pin nail may be used, except in hard woods, in which the 1 inch pin nail tends to hold in the wood of the groove too securely. The preferred pin nail gauge is 18. Larger diameter pin nails work less well, because they stick in the wood of the groove too tightly. Typically, the preferred pin nails are installed through the tongue 24 and into the groove 22, by use of an air gun, so that the act of installing the pin nail also creates the hole 46 in the groove in which the pin nail slides for expansion. Preferably, therefore, the holes in the grooves are not predrilled but created by installing the pin nails.
Thus, the expandable feature of the pin connection depends upon having pins of the proper size, length, and spacing, and the proper limitation on how close the pins can be to the end of the ends of the casings. The preferred pins is the pin nail described above, but alternatively, another pin could be used, even one that is inserted into the tongue from the underside of the tongue rather than completely through the tongue, as long as the pin protrudes the desired distance out from the underside of the tongue in the desired spacing and location. Also, other positions and spacing of pin nails or other expandable connection means may be used, as long as the casings are held on the jambs, but in an expandable manner. It has been found that conventional stapling of casings to jambs does not provide the selfaligning feature.
The preferred door assembly may be packaged as a kit 50, for improving storage, handling, transport, marketing, and appearance on a store shelf. Do-it-your-selfers, especially, benefit from being able to buy a kit containing the invented door assembly, with connected and self-aligning casings. Preferably, the side jamb-casing assemblies 52 are nested, as shown in FIGS. 6 and 7, with the underside or inside 54 of the jamb and casings facing each other, and with the head jamb-casing assembly 55 along the side of the side jamb-casing assemblies 52 at the bottom of the kit 50. The jamb-casing assemblies 52, 55 then receive an end-cap 56 on each end, and may, optionally, be wrapped with transparent plastic wrap or shrink wrap. Thus, the jamb-casing assemblies 52, 55 are held together in a compact, manageable package. Optionally, hinges, shimming hardware, tools, instruction sheets or other items to aide the do-it-your-selfer may be included in the kit 50, to make it a self-contained, complete kit.
Installation of the invented door assembly 10 and use of the kit 50 may be done by the following methods. The head jamb-casing assembly 55 is installed at the top of the roughed-in frame opening The side jamb-casing assemblies 52 are then installed by inserting the top ends 19 of the side jambs 12 up into the brackets 28, while holding the assemblies 52 at a slight angle to the side studs, and then pivoting the assemblies 52 into place close to the side studs of the roughed-in frame. As the jamb-casing assemblies 55, 52 are pushed into their horizontal and vertical positions, respectively, the casings 16, 16' self-align, as described above, to fit the shape of the roughed-in frame. After the jamb-casing assemblies are in place and self-aligned, and shimming hardware adjusted as necessary, the installer may nail or screw the jambs or casings into permanent position.
Shimming hardware is optionally included in the kit 50 for use between jambs 12 and/or 14 and the stud lumber present in the wall's door opening in order to attain and maintain proper fit of the various component parts of the door assembly 10. Two sets of shimming hardware are preferably placed between the head jamb and the stud, with the adjustment members of the hardware being accessible through two holes bored through the head jamb 14. Shimming hardware is also preferably used with the side jamb-casing assemblies 52, for example, by positioning the shimming hardware between the side jambs 12 and the studs and accessing adjustment members through holes drilled through the hinge-side jamb 12 at the positions where the hinges are to be placed, and through the other side jamb at the position of the strike plate.
The framing system and the expandable connection system of this invention as recited in the description and claims is intended to also include window wrap applications.
The foregoing detailed description is intended to be an illustrative, not a restrictive, description of functional features of the preferred embodiment of the invention. The scope of the invention is indicated by the Claims following and any variations which fall within the meaning and range of equivalency of the Claims are therefore embraced therein.
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The invention is a prefabricated door assembly for installation in a roughed-in door frame. The assembly includes a pair of vertically extending door jambs having interengaging casings and a header unit spanning the upper ends of the door jambs. The header unit includes a header board or jamb having interengaging horizontal casings. Both horizontal and vertical casings have pin nails protruding from their tongue portions which engage the jambs lightly during transport and installation prior to final nailing in place. The assembly also includes L-shaped brackets affixed to the upper outer corners which join and fasten the vertical and horizontal jambs together. The assembly may be packaged as a kit, which may include hinges, shims and/or shimming hardware.
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RELATED APPLICATIONS
[0001] The present application is a National Phase entry of International Application No. PCT/JP2015/051693, filed Jan. 22, 2015, which claims priority of Japanese Application No. 2014-070528, filed Mar. 28, 2014.
TECHNICAL FIELD
[0002] The present disclosure relates to a wet tissue and to a method of producing the wet tissue.
BACKGROUND ART
[0003] Wet tissues of the type that can be flushed in toilets have been developed and are commercially available. For flushing in a toilet, a wet tissue must have a prescribed level of wet strength, considering how it is to be used, and a prescribed level of water disintegratability, considering that it is to be flushed in a toilet. In the relevant technical field, it is common to achieve both wet strength for use and water disintegratability by addition of chemical agents.
[0004] For example, PTL 1 describes a water disintegratable sheet containing a water-soluble polymer (methyl cellulose, hydroxypropyl methyl cellulose or the like) and at least one type of compound containing a benzene nucleus substituted with at least two hydroxyl groups (resorcin, pyrocatechol, pyrogallol, phloroglucinol or the like), and a water disintegratable wet tissue.
[0005] Also, PTL 2 describes a layered nonwoven fabric having at least two different types of nonwoven fabrics, a water disintegratable nonwoven fabric composed of water disintegratable fibers including ionic fibers formed from a resin composition containing a cationic resin (for example, cationized cellulose, cationized starch, cationized guar gum, cationized dextrin or polydimethylmethylenepiperidinium chloride), and an anionic resin (for example, a polyacrylic acid salt, carboxymethyl cellulose, carboxymethyl starch, alginic acid, xanthan gum or a polymethacrylic acid salt), and a staple fiber nonwoven fabric formed from staple fibers, layered in a water disintegratable manner.
[0006] Furthermore, PTL 3 describes a water disintegratable cleaning article comprising a water disintegratable sheet obtained by high-pressure water jet spray treatment of a wet web containing wood pulp, biodegradable synthetic fiber, a water-soluble binder with a carboxyl group and a cationic polymer, which is impregnated with an aqueous cleaning agent containing one or more different metal ions selected from among alkaline earth metals, manganese, zinc, cobalt and nickel, and an organic solvent, the water disintegratable sheet having a multi-ply structure obtained by stacking and embossing of two or more monolayer sheets, the monolayer sheet composing the outermost layer being subjected to high-pressure water jet spray treatment from each surface, and being stacked so that the treated surface is facing outward.
[0007] In addition, PTL 4 describes a water disintegratable sheet employing an anionic adhesive (carboxymethyl cellulose sodium, carrageenan, sodium polyuronate and the like) and a cationic oligomer represented by formula (1) or (2).
[0008] Moreover, as a wet tissue of a type using no chemical agent, PTL 5 describes a water disintegratable fiber sheet including unbeaten pulp (a) with a beating degree of 700 mL or greater, beaten pulp (b) with a beating degree of 400 to 650 mL, regenerated cellulose (c) with a beating degree of 700 mL or greater and refined fibrillated cellulose (d) with a beating degree of 0 to 400 mL.
CITATION LIST
Patent Literature
[0009] PTL 1 Japanese Unexamined Patent Publication No. 2001-3297
[0010] PTL 2 Japanese Unexamined Patent Publication No. 2001-138424
[0011] PTL 3 Japanese Unexamined Patent Publication No. 2008-2017
[0012] PTL 4 Japanese Unexamined Patent Publication No. 2009-52152
[0013] PTL 5 Japanese Unexamined Patent Publication No. 2010-285718
SUMMARY OF INVENTION
Technical Problem
[0014] The wet tissues with water disintegratability described in PTL 1 to 4 exhibit both wet strength and water disintegratability by the action of chemical agents. However, considering that a wet tissue is to contact human skin, it is desirable to develop a wet tissue that exhibits both wet strength and water disintegratability without including chemical agents.
[0015] Furthermore, while the water disintegratable fiber sheet described in PTL 5 achieves both wet strength and water disintegratability by addition of refined fibrillated cellulose, there is demand for a wet tissue that exhibits both wet strength and water disintegratability by different methods.
[0016] It is therefore an object of the present disclosure to provide a wet tissue that exhibits both wet strength and water disintegratability.
Solution to Problem
[0017] The inventors have discovered a wet tissue with water disintegratability, including a multilayer sheet comprising a first sheet and a second sheet, wherein the first sheet includes a first hydrophilic fiber-containing layer including hydrophilic fibers at 95 to 100 mass % and a first hydrophobic fiber-containing layer including hydrophobic fibers at 5 to 30 mass %, and the second sheet includes a second hydrophilic fiber-containing layer including hydrophilic fiber at 95 to 100 mass % and a second hydrophobic fiber-containing layer including hydrophobic fiber at 5 to 30 mass %, the first hydrophobic fiber-containing layer being disposed adjacent to the second hydrophobic fiber-containing layer, the multilayer sheet having a plurality of connected sections, disposed across spacings, where the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer are connected, the spacings between the plurality of connected sections being 0.6 times or above the mean fiber length of the hydrophobic fibers of the first hydrophobic fiber-containing layer and 0.6 times or above the mean fiber length of the hydrophobic fibers of the second hydrophobic fiber-containing layer, the plurality of connected sections having an area ratio of 0.5 to 12.0% with respect to the multilayer sheet, and each of the first sheet and second sheet, which is separated from the multilayer sheet, having a disintegratability of 100 seconds or less in a disintegration test, the multilayer sheet having a bending resistance of 150 mm or less, and the wet tissue having a tensile strength of 1.0N or greater per 25 mm width.
Advantageous Effects of Invention
[0018] The wet tissue of the present disclosure exhibits both wet strength and water disintegratability.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 is a plan view of a wet tissue according to one embodiment of the present disclosure.
[0020] FIG. 2 is a cross-sectional view along plane II-II of FIG. 1 .
[0021] FIG. 3 is a schematic diagram for illustration of the relationship between the connected section spacings and the fiber length.
[0022] FIG. 4 is a cross-sectional view of a wet tissue according to another embodiment of the present disclosure.
[0023] FIG. 5 is a schematic diagram for illustration of a method of producing a wet tissue according to one embodiment of the present disclosure.
[0024] FIG. 6 is a schematic diagram for illustration of a method of producing a wet tissue according to one embodiment of the present disclosure.
DESCRIPTION OF EMBODIMENTS
Definitions
[0025] Several terms will be defined before describing the wet tissue of the present disclosure.
[0026] “Mean Fiber Length”
[0027] As used herein, the mean fiber length of the fibers including the hydrophilic fibers and hydrophobic fibers is the weight-weighted average fiber length, and it is the L(w) value measured using Kajaani fiber Lab fiber properties (off-line)] by Metso Automation.
[0028] “Melting Point”
[0029] As used herein, the term “melting point” of hydrophobic fibers refers to the peak top temperature for the endothermic peak during conversion from solid to liquid, upon measurement with a differential scanning calorimetry analyzer at a temperature-elevating rate of 10° C./min. The differential scanning calorimetry analyzer used may be, for example, a DSC-60-type DSC measuring apparatus by Shimadzu Corp.
[0030] When the hydrophobic fiber includes multiple components, the melting point is measured for each component.
[0031] “Machine Direction” and “Cross-Machine Direction”
[0032] As used herein, the machine direction is the machine direction during production, and the cross-machine direction is the direction perpendicular to the machine direction during production.
[0033] “Spacing” for Connected Sections
[0034] As used herein, the “spacing” of the connected sections is the distance (inner distance) from one inner side to the other inner side between one connected section and the connected section located nearest to that connected section. In FIG. 3 , the spacing 1 is the inner distance between a connected section 5 d and a connected section 5 e located nearest to the connected section 5 d.
[0035] “Pitch” for Connected Sections
[0036] As used herein, the “pitch” between the connected sections is the center distance between one connected section and the connected section located nearest to that connected section. In FIG. 3 , the pitch P is the center distance between the connected section 5 d and the connected section 5 e located nearest to the connected section 5 d.
[0037] The wet tissue of the present disclosure, and a method of producing the wet tissue, will now be explained in detail.
<Wet Tissue>
[0038] The wet tissue of the present disclosure includes a multilayer sheet with water disintegratability, comprising a first sheet and a second sheet.
[0039] As used herein, “wet tissue” and “multilayer sheet” differ in that a “wet tissue” includes a chemical solution while a “multilayer sheet” does not include a chemical solution.
[0040] Also, in the drawings for the wet tissue of the present disclosure, the second sheet will sometimes appear to be stacked on the first sheet, but this appearance is not intended to restrict the use of the wet tissue. That is, the surface of the first sheet opposite the second sheet is capable of wiping off dirt, while the surface of the second sheet opposite the first sheet is also capable of wiping off dirt.
[0041] In the wet tissue of the present disclosure, the first sheet includes a first hydrophilic fiber-containing layer including hydrophilic fibers at 95 to 100 mass % and a first hydrophobic fiber-containing layer including hydrophobic fibers at 5 to 30 mass %, while the second sheet includes a second hydrophilic fiber-containing layer including hydrophilic fibers at 95 to 100 mass % and a second hydrophobic fiber-containing layer including hydrophobic fibers at 5 to 30 mass %. Moreover, in the wet tissue of the present disclosure, the first hydrophobic fiber-containing layer is disposed adjacent to the second hydrophobic fiber-containing layer, and the multilayer sheet has a plurality of connected sections, disposed across spacings, that connect the first hydrophobic fiber-containing layer and second hydrophobic fiber-containing layer. These will now be explained with reference to FIG. 1 to FIG. 3 .
[0042] FIG. 1 shows a plan view of a wet tissue according to an embodiment of the present disclosure, and FIG. 2 shows a cross-sectional view along plane II-II of FIG. 1 . In the wet tissue 1 depicted in FIG. 1 and FIG. 2 , the first sheet includes a first hydrophilic fiber-containing layer 2 a including hydrophilic fibers (not shown) at 95 to 100 mass % and a first hydrophobic fiber-containing layer 2 b including hydrophobic fibers (not shown) at 5 to 30 mass %, while the second sheet 3 includes a second hydrophilic fiber-containing layer 3 a including hydrophilic fibers (not shown) at 95 to 100 mass % and a second hydrophobic fiber-containing layer 3 b including hydrophobic fibers (not shown) at 5 to 30 mass %.
[0043] Moreover, in the wet tissue 1 depicted in FIG. 1 and FIG. 2 , the first hydrophobic fiber-containing layer 2 b is disposed adjacent to the second hydrophobic fiber-containing layer 3 b , and the multilayer sheet 4 has a plurality of connected sections 5 formed by connecting the first hydrophobic fiber-containing layer 2 b and second hydrophobic fiber-containing layer 3 b . Specifically, in the wet tissue 1 of FIG. 1 and FIG. 2 , the multilayer sheet 4 has a plurality of embossed sections 5 ′ formed by embossing the first hydrophobic fiber-containing layer 2 b and the second hydrophobic fiber-containing layer 3 b . In the multilayer sheet 4 , the plurality of embossed sections 5 ′ are configured in a zigzag fashion.
[0044] In the embodiment shown in FIG. 1 and FIG. 2 , the connected sections are embossed sections, but the connected sections in the wet tissue of the present disclosure are not limited to being embossed sections. In a wet tissue according to several other embodiments of the present disclosure, the connected sections are, for example, adhesive sections formed by an adhesive, or pressure-sensitive adhesive sections formed by a pressure-sensitive adhesive.
[0045] The connected sections may be formed by connecting the surface of the first sheet, and specifically the surface of the first hydrophobic fiber-containing layer that is opposite the first hydrophilic fiber-containing layer, and the surface of the second sheet, and specifically the surface of the second hydrophobic fiber-containing layer that is opposite the second hydrophilic fiber-containing layer, but preferably the connected sections are formed by further connecting the fibers inside either the first hydrophobic fiber-containing layer or the second hydrophobic fiber-containing layer, and more preferably they are formed by further connecting the fibers inside both the first sheet and the second sheet. This is from the viewpoint of the wet strength of the wet tissue.
[0046] From the viewpoint of connecting the fibers inside either or both the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer, the connected sections are preferably embossed sections. When the connected sections are embossed sections, the hydrophobic fibers of the first hydrophobic fiber-containing layer and second hydrophobic fiber-containing layer preferably include heat-fusible fibers, and more preferably they include heat-fusible fibers comprising composite fibers that include a low-melting-point component and a high-melting-point component having a higher melting point than the low-melting-point component (hereunder also referred to as “heat-fusible fibers comprising composite fibers that include a low-melting-point component and a high-melting-point component”).
[0047] In the embossed sections, preferably at least some of the hydrophobic fibers of the first hydrophobic fiber-containing layer (the low-melting-point component of the heat-fusible fibers) are fused with the hydrophobic fibers of the second hydrophobic fiber-containing layer, and when the second hydrophobic fiber-containing layer includes the hydrophilic fibers described below, preferably at least some of the (low-melting-point component of the) heat-fusible fibers of the first hydrophobic fiber-containing layer are fused with the hydrophilic fibers of the second hydrophobic fiber-containing layer. This is from the viewpoint of the wet strength of the wet tissue.
[0048] From the same viewpoint, in the embossed sections, preferably at least some of the hydrophobic fibers of the second hydrophobic fiber-containing layer (the low-melting-point component of the heat-fusible fibers) are fused with the hydrophobic fibers of the first hydrophobic fiber-containing layer, and when the first hydrophobic fiber-containing layer includes the hydrophilic fibers described below, preferably at least some of the (low-melting-point component of the) heat-fusible fibers of the second hydrophobic fiber-containing layer are fused with the hydrophilic fibers of the first hydrophobic fiber-containing layer.
[0049] From the same viewpoint, when the connected sections are adhesive sections, preferably the viscosity of the adhesive is reduced so that it seeps into either or both the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer, and preferably the adhesive bonds with the fibers contained in either or both the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer. This also applies when the connected sections are pressure-sensitive adhesive sections.
[0050] In the wet tissue of the present disclosure, the connected sections may have connecting of the fibers, such as the hydrophilic fibers, included in the first hydrophilic fiber-containing layer and/or the second hydrophilic fiber-containing layer, but preferably the connected sections are not present on the outermost surface (the use-surface) of the multilayer sheet. This is because the connected sections, or embossed sections, for example, tend to be harder than the nonwoven fabric sections, and when the connected sections are present on the outermost surface (use-surface) of the multilayer sheet, the user will tend to sense a feeling of hardness.
[0051] If the wet tissue has the aforementioned connected sections, the wet tissue, when wet, will tend to exhibit wet strength that is a combination of the wet strength of the first sheet and the wet strength of the second sheet, and when disintegrated by water, it will tend to exhibit the individual water disintegratability of the first sheet and second sheet.
[0052] For example, when the first sheet and second sheet are the same sheet, the wet tissue of the present disclosure will tend to exhibit twice the wet strength of the first sheet, and to exhibit the same water disintegratability as the first sheet.
[0053] In the wet tissue of the present disclosure, the spacing between the plurality of connected sections is 0.6 times or above, preferably 0.7 times or above, more preferably 0.8 times or above, even more preferably 1.0 times or above, yet more preferably 1.5 times or above, and even yet more preferably 2.0 times or above the mean fiber length of the hydrophobic fibers of the first hydrophobic fiber-containing layer.
[0054] Also, in the wet tissue of the present disclosure, the spacing between the plurality of connected sections is 0.6 times or above, preferably 0.7 times or above, more preferably 0.8 times or above, even more preferably 1.0 times or above, yet more preferably 1.5 times or above, and even yet more preferably 2.0 times or above the mean fiber length of the hydrophobic fibers of the second hydrophobic fiber-containing layer.
[0055] The reason for which the spacing between the plurality of connected sections is 0.6 times or above the mean fiber length of the hydrophobic fibers in both the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer will now be explained with reference to FIG. 3 .
[0056] FIG. 3 is a schematic diagram for illustration of the relationship between the connected section spacings and the fiber length. FIG. 3 is a plan view of region III of FIG. 1 , the second sheet 3 being omitted for ease of explanation. Also in FIG. 3 , the only hydrophobic fibers of the first hydrophobic fiber-containing layer 2 b shown are the hydrophobic fibers 6 a , 6 b and 6 c connected to the connected sections 5 a , 5 b and 5 c.
[0057] If the spacing 1 between the connected sections 5 is longer than the mean fiber length of the hydrophobic fibers 6 of the first hydrophobic fiber-containing layer 2 b , the hydrophobic fibers 6 a connected to the connected section 5 a , for example, will not connect with the adjacent connected section 5 b (or 5 c ) even if they are tangled with the hydrophobic fibers 6 b (or 6 c ) connected to the adjacent connected section 5 b (or 5 c ) at a tangled point lab (or 7 ac ). In other words, the adjacent connected sections 5 a to 5 c are not connected by the hydrophobic fibers 6 a to 6 c . Therefore, when the wet tissue has been discarded in a flush toilet, the connected sections 5 a to 5 c easily separate into separate fragments so that the water disintegratability of the wet tissue is less likely to be reduced.
[0058] The relationship between the spacing between the connected sections and the fiber lengths is the same as for the second hydrophobic fiber-containing layer.
[0059] In a nonwoven fabric, such as a wet tissue, the fibers composing the nonwoven fabric generally do not exist in a straight linear form, but are tangled with other fibers and meandering. Thus, even when the spacing 1 between the connected sections 5 is shorter than the mean fiber length of the hydrophobic fibers 6 , the connected sections 5 a to 5 c will often be separable into different fragments when discarded in a flush toilet or the like.
[0060] It has been confirmed by the present inventors that if the spacing of the connected sections is 0.6 times or above the mean fiber length of the hydrophobic fibers in both the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer, it is possible to achieve disintegratability of 100 seconds or less in a disintegration test.
[0061] Thus, in consideration of water disintegratability, the plurality of connected sections must have a spacing of 0.6 times or above the mean fiber length of the hydrophobic fibers in both the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer.
[0062] In the wet tissue of the present disclosure, when the first hydrophobic fiber-containing layer and/or the second hydrophobic fiber-containing layer includes a fiber type other than hydrophobic fibers (for example, hydrophilic fibers), the spacing between the plurality of connected sections is preferably 0.6 times or above, more preferably 0.7 times or above, even more preferably 0.8 times or above, yet more preferably 1.0 times or above, even yet more preferably 1.5 times or above, and most preferably 2.0 times or above the mean fiber length of each of the fibers types in the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer.
[0063] Incidentally, since the hydrophilic fibers are connected by hydrogen bonding with the other fibers, and particularly the hydrophilic fibers, the connecting points by hydrogen bonding with the other fibers readily disappear upon disposal in a flush toilet or the like. Thus, the mean fiber length of the hydrophilic fibers has less of an effect on the water disintegratability of the wet tissue than the mean fiber length of synthetic fibers, especially when the connected sections are embossed sections.
[0064] In the wet tissue of the present disclosure, the lower limit for the area ratio of the connected sections with respect to the multilayer sheet will differ depending on the area of the individual connected sections, but it is generally 0.5% or greater, preferably 1.0% or greater, more preferably 1.2% or greater and even more preferably 1.5% or greater. If the area ratio is less than 0.5%, connection between the first sheet and the second sheet will be insufficient, resulting in reduced wet strength of the wet tissue and possible tearing of the wet tissue during use.
[0065] The upper limit for the area ratio will also differ depending on the area of the individual connected sections and the number density of the connected sections, but it is generally 12% or less, preferably 10.0% or less, more preferably 8.0% or less, and even more preferably 5.0% or less. If the area ratio is greater than 12.0%, connection between the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer will be strong and the wet strength of the wet tissue will be increased, but when the wet tissue has been discarded in a flush toilet, the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer will have difficulty separating, the water disintegratability of the wet tissue may be reduced, and the bending resistance of the wet tissue will tend to increase (the wet tissue will become hard).
[0066] This upper limit is preferred when the number density of the connected sections is low, such as when the connected sections have a number density of preferably 10 to 1,000/m 2 and more preferably 50 to 500/m 2 .
[0067] As an example where the number density of the connected sections is low, there may be mentioned a working example in which the connected sections are linear connected sections.
[0068] When the number density of the connected sections is high, such as when the connected sections have a number density of 1,000 to 100,000/m 2 and more preferably 10,000 to 70,000/m 2 , the upper limit for the area ratio is preferably 5.0% or less, more preferably 4.5% or less, even more preferably 4.0% or less, and yet more preferably 3.8% or less. As an example where the number density of the connected sections is high, there may be mentioned a working example in which the connected sections are punctiform connected sections.
[0069] The area ratio of the connected sections is calculated by the following formula.
[0000] Area ratio of connected sections (%)=100×(total area of connected sections, mm 2 )/(area of multilayer sheet, mm 2 )
[0070] The number density of the connected sections is the number of connected sections per 1 m 2 of the multilayer sheet.
[0071] The form of the connected sections is not particularly restricted, and examples of connected sections include punctiform connected sections, for example, connected sections with circular, elliptical, rectangular or triangular shapes, star shapes, heart shapes or any desired character shapes or symbol shapes.
[0072] Also, the punctiform connected sections may be disposed on the multilayer sheet without any particular restrictions so long as the spacing is within the prescribed relationship with the mean fiber length of the hydrophobic fibers of both the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer, and the punctiform connected sections may be disposed, for example, in an arrangement that is zigzag, such as a square zigzag or 60° zigzag.
[0073] The connected sections may be linear connected sections, such as straight linear connected sections or non-linear connected sections, such as curved connected sections.
[0074] Linear connected sections may be arranged, for example, in parallel or non-parallel.
[0075] In the wet tissue of the present disclosure, the area per each connected section also varies depending on the area ratio of the connected sections, the shapes of the connected sections, and other factors, but when the connected sections are punctiform connected sections, each of the connected sections has an area of preferably 0.4 to 9.0 mm 2 , more preferably 0.4 to 7.0 mm 2 and even more preferably 1.0 to 5.0 mm 2 . If the area is less than 0.4 mm 2 , connection between the first sheet and the second sheet may be insufficient, and if the area is greater than 9.0 mm 2 , the wet strength of the wet tissue will tend to be reduced.
[0076] Furthermore, when the connected sections are embossed sections, and the area is less than 0.4 mm 2 , the protrusions on the embossing roll for formation of the embossed sections will be more acute angles which may open holes in the wet tissue, and when the number of embossed sections is increased to increase the wet strength it will become difficult to ensure the spacing between the embossed sections, while if the area is greater than 9.0 mm 2 , the skin of the user will tend to sense the hardness of the embossed sections.
[0077] When the connected sections are linear connected sections, the connected sections have widths of preferably 0.3 to 3.0 mm, more preferably 0.5 to 2.5 mm and even more preferably 1.0 to 2.0 mm. If the widths are less than 0.3 mm, connection between the first sheet and the second sheet may be insufficient, and the wet strength of the wet tissue may be insufficient. If it exceeds 3.0 mm, the wet strength of the wet tissue will increase but the water disintegratability of the wet tissue will tend to be reduced.
[0078] Moreover, when the connected sections are embossed sections, and the widths are less than 0.3 mm, the protrusions of the embossing rolls for formation of the embossed sections will be more acute angles, which may potentially open holes in the wet tissue.
[0079] In the wet tissue of this disclosure, each of the first hydrophilic fiber-containing layer and second hydrophilic fiber-containing layer includes a prescribed amount of hydrophilic fibers, and each of the first hydrophobic fiber-containing layer and second hydrophobic fiber-containing layer includes a prescribed amount of hydrophobic fibers.
[0080] As used herein, the simple term “fiber” refers to all of the types of fibers in the first sheet, the second sheet, the first hydrophilic fiber-containing layer or second hydrophilic fiber-containing layer, or in the first hydrophobic fiber-containing layer or second hydrophobic fiber-containing layer.
[0081] Each of the first hydrophilic fiber-containing layer and second hydrophilic fiber-containing layer includes hydrophilic fibers at 95 to 100 mass %, preferably include hydrophilic fibers at 97 to 100 mass % and more preferably include hydrophilic fibers at 100 mass %. If the first hydrophilic fiber-containing layer and second hydrophilic fiber-containing layer include hydrophilic fibers in such amounts, the layer will have excellent feel on the skin. Also, when the hydrophobic fibers are heat-fusible fibers and the connected sections are embossed sections, the embossing roll used to form the embossed sections will be less likely to be fouled, while the user will not directly contact the embossed sections so that the user will be less likely to feel the hardness of the embossed sections.
[0082] Each of the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer includes hydrophobic fibers at 5 to 30 mass %, preferably include hydrophobic fibers at 6 to 25 mass %, and more preferably include hydrophobic fibers at 7 to 20 mass %. If the proportion of hydrophobic fibers is less than 5 mass %, the wet strength of the wet tissue will tend to be reduced, and if the proportion of hydrophobic fibers exceeds 30 mass %, the water disintegratability will tend to be reduced.
[0083] Furthermore, when the hydrophobic fibers are heat-fusible fibers and the connected sections are embossed sections, and the proportion of hydrophobic fibers is less than 5 mass %, the connecting force between the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer by the embossed sections will be reduced and the water disintegratability of the wet tissue will increase, but the wet strength will also be reduced, tending to result in tearing during use, and also tending to reduce the bending resistance (resulting in softness).
[0084] Furthermore, when the hydrophobic fibers are heat-fusible fibers and the connected sections are embossed sections, and the proportion of hydrophobic fibers is greater than 30 mass %, the connecting force between the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer by the embossed sections will be increased and the wet strength of the wet tissue will increase, but the water disintegratability will also tend to be inferior and the bending resistance will tend to increase (result in hardness).
[0085] Each of the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer preferably further include hydrophilic fibers. This is from the viewpoint of retentivity of chemical solutions.
[0086] When the first hydrophobic fiber-containing layer includes hydrophilic fibers, the first hydrophobic fiber-containing layer includes hydrophobic fibers and hydrophilic fibers, respectively, at 5 to 30 mass % and 70 to 95 mass %, preferably 6 to 25 mass % and 75 to 94 mass % and more preferably 7 to 20 mass % and 80 to 93 mass %.
[0087] When the second hydrophobic fiber-containing layer includes hydrophilic fibers, the preferred proportion of hydrophobic fibers and hydrophilic fibers in the second hydrophobic fiber-containing layer is as explained above for the first hydrophobic fiber-containing layer.
[0088] The hydrophilic fibers are not particularly restricted so long as they are fibers with hydrophilicity and capable of retaining water on the surface or in the interiors. For example, the hydrophilic fibers may be cellulosic fibers, examples of cellulosic fibers including pulp and regenerated cellulose fibers.
[0089] Examples of pulp include wood pulp and nonwood pulp. Examples of wood pulp include conifer pulp and broadleaf tree pulp. Examples of nonwood pulp include straw pulp, bagasse pulp, reed pulp, kenaf pulp, mulberry pulp, bamboo pulp, hemp pulp and cotton pulp (such as cotton linter).
[0090] Also, the pulp may be non-beaten pulp that has not been subjected to beating treatment, beaten pulp that has been subjected to beating treatment, or a combination thereof.
[0091] Non-beaten pulp preferably has a Canadian Standard Freeness of 700 mL or greater.
[0092] The Canadian Standard Freeness (CSF) is measured according to JIS P 8121-222012, “Pulp Freeness Test Method—Part 2: Canadian Standard Freeness Method”.
[0093] The mean fiber length of the non-beaten pulp is not particularly restricted but is generally preferred to be 2 to 4 mm from the viewpoint of economy and productivity.
[0094] Beaten pulp is pulp obtained by beating non-beaten pulp by a method, such as free beating or wet beating, and it has main body sections and microfiber sections extending from the main body sections. If the wet tissue includes beaten pulp, the wet strength and dry strength of the wet tissue will be increased.
[0095] The beaten pulp preferably has a Canadian Standard Freeness of 400 to 650 mL, and more preferably it has a Canadian Standard Freeness of 400 to 600 mL.
[0096] The regenerated cellulose fibers may be a rayon, such as viscose rayon obtained from viscose, polynosic and modal, or cuprammonium rayon obtained from cuprammonium salt solutions of cellulose, (also known as “cupra”); or lyocell, such as Tencel®, which are not via cellulose derivatives, obtained by organic solvent spinning methods using organic solvents that are mixed solutions of organic compounds and water.
[0097] The regenerated cellulose fibers are preferably rayon and especially viscose rayon, from the viewpoint of water absorption, ease of forming the first hydrophilic fiber-containing layer and second hydrophilic fiber-containing layer, and economy.
[0098] Furthermore, the cellulosic fibers may be, for example, semi-synthetic cellulose fibers, such as acetate fibers, among which triacetate fibers and diacetate fibers may be mentioned.
[0099] The hydrophobic fibers may be ones commonly used in the technical field, and are preferably synthetic fibers. The synthetic fibers may be ones containing only a single component, such as simple fibers, or ones containing multiple components, such as composite fibers.
[0100] Examples of the components include polyolefin-based polymers, such as polyethylene and polypropylene; polyester-based polymers, for example, terephthalate-based polymers, such as polyethylene terephthalate (PET), polybutylene terephthalate and polypentylene terephthalate; polyamide-based polymers, such as nylon 6 and nylon 6,6; acrylic polymers; polyacrylonitrile-based polymers; and their modified forms.
[0101] When the connected sections are embossed sections, the hydrophobic fibers preferably include heat-fusible fibers, and more preferably they include heat-fusible fibers comprising composite fibers that include a low-melting-point component and a high-melting-point component having a higher melting point than the low-melting-point component.
[0102] In the heat-fusible fibers, the low-melting-point component has a melting point of preferably 120 to 180° C., more preferably 130 to 170° C. and even more preferably 140 to 160° C. If the melting point is lower than 120° C., the drying temperature of the first sheet and/or second sheet will need to be lowered to below the melting point of the low-melting-point component in order to prevent fusion of the low-melting-point component, and the productivity of the wet tissue will tend to be reduced.
[0103] In the heat-fusible fibers, the high-melting-point component has a melting point of preferably 170 to 300° C., more preferably 180 to 290° C., even more preferably 200 to 270° C. and yet more preferably 220 to 260° C. If the melting point is lower than 170° C., not only the low-melting-point component but also the high-melting-point component will undergo melting during the embossing step, and the embossed sections will become hard, sometimes lowering the feel of the wet tissue on the skin. The melting point is preferably not higher than 300° C. from the viewpoint of economy.
[0104] In the heat-fusible fibers, the low-melting-point component and high-melting-point component have a difference in melting point of preferably 50 to 110° C., more preferably 60 to 100° C. and even more preferably 70 to 90° C. If the difference in melting point is less than 50° C., it will tend to be difficult to melt only the low-melting-point component in the embossing step, while if the difference in melting point is greater than 110° C., the melting point of the low-melting-point component will be lower, often resulting in melting of the low-melting-point component during drying of the first sheet and/or second sheet, or the melting point of the high-melting-point component will be high, which is undesirable in terms of economy.
[0105] The low-melting-point component and high-melting-point component are not particularly restricted, and may be selected from among the polymers listed for the hydrophobic synthetic fibers.
[0106] The low-melting-point component is preferably a terephthalate-based polymer with a lower melting point than PET, and the high-melting-point component is preferably PET.
[0107] The composite fibers may be, for example, core-sheath type, core-sheath eccentric type or side-by-side type fibers.
[0108] In the wet tissue of the present disclosure, each of the first sheet and second sheet separated from the multilayer sheet exhibits, in a disintegration test as an indicator of water disintegratability, a disintegratability of 100 seconds or less, and preferably exhibits a disintegratability of 90 seconds or less, more preferably 80 seconds or less, and even more preferably 70 seconds or less. If the disintegratability exceeds 100 seconds, toilet pipes etc. may become clogged, depending on their thickness. There is no particular lower limit on the disintegratability.
[0109] In Table 1 of “2. Quality” for toilet paper in JIS P 4501:1993 it is stated that toilet paper should satisfy the standard of a disintegratability of no more than 100 seconds, and considering that the wet tissue of the present disclosure is to be discarded in a flush toilet, it preferably has disintegratability equivalent to that of toilet paper.
[0110] For the purpose of the present disclosure, the water disintegratability of the first sheet and second sheet separated from the multilayer sheet is used because when the wet tissue is discarded in a flush toilet, usually the water stream strips off the first sheet and second sheet at a relatively early stage, followed by the fragments.
[0111] In Table 1 of “2. Quality” for toilet paper in JIS P 4501:1993, it is stated that the aforementioned disintegratability standard is applied for each single sheet when two or more sheets are wound together.
[0112] The multilayer sheet is obtained by drying of the wet tissue for 24 hours under conditions of 20±5° C., 65±5% RH, and vaporizing off the chemical solution from the wet tissue.
[0113] The wet tissue of the present disclosure preferably also has a disintegratability of 100 seconds or less in a disintegration test for the wet tissue itself, assuming that the first sheet and second sheet will not separate when discarded in a flush toilet, such as when the water stream is weak.
[0114] Throughout the present specification, the disintegration test is conducted according to “4.5 Disintegratability” for toilet paper of JIS P 4501:1993. Specifically, it is as follows.
[0115] A 300 mL beaker containing 300 mL of water (water temperature: 20° C.±5° C.) is placed in a magnetic stirrer, and the rotational speed of the rotor (discoid rotor with diameter: 35 mm, thickness: 12 mm) is adjusted to 600±10 rpm. A test strip with 114±2 mm sides is loaded into a beaker, and a stopwatch is activated. The rotational speed of the rotor first falls to about 500 rpm due to the resistance of the test strip, the rotational speed increasing as the test strip becomes loose, and upon recovering to 540 rpm, the stopwatch is stopped and the time is measured in second units. The results of disintegratability are expressed as a mean value for 5 tests.
[0116] The wet tissue of the present disclosure before impregnation of the chemical solution, i.e. the multilayer sheet, has a bending resistance of 150 mm or less, preferably a bending resistance of 145 mm or less, and more preferably 140 mm or less, and more preferably it has a bending resistance of preferably 135 mm or less. If the bending resistance is greater than 150 mm, the user will tend to feel hardness in the wet tissue. There is no particular lower limit for the bending resistance, but it will generally be 20 mm or above.
[0117] As used herein, the bending resistance is measured according to “6.7.3 41.5 Cantilever method” of the general test methods for nonwoven fabrics of JIS L 1913:2010, except that the length of the test strip was changed from “(25±1) mm×(250±1) mm” to “(25±1) mm×(200±1) mm”.
[0118] The bending resistance is preferably within the range specified above in any direction of the multilayer sheet, for example, in both the longitudinal and widthwise directions according to the aforementioned JIS standard, such as in both the machine direction and the cross-machine direction during production of the first sheet and the second sheet.
[0119] The wet tissue of the present disclosure has a tensile strength of 1.0N or greater and preferably 1.1N or greater per 25 mm width. If the tensile strength is lower than 1.0N per 25 mm width, the wet tissue can potentially tear when the wet tissue is removed.
[0120] Throughout the present specification, the tensile strength of the wet tissue may be referred to as the “wet strength” of the wet tissue, and the units of the tensile strength per 25 mm width of the wet tissue may be expressed as “N/25 mm”.
[0121] The tensile strength is preferably within the range specified above in any direction of the wet tissue, such as in both the machine direction and the cross-machine direction during production of the first sheet and second sheet.
[0122] The tensile strength is measured according to “7.1 General method” of the Wet Tensile Strength Test Methods for Paper or Boards” of JIS P 8135:1998, except for the difference specified below.
[0123] A multilayer sheet is cut to 25 mm width×150 mm length to prepare a sample, which is immersed in distilled water with a mass ratio of 250 mass %, after which the sample is set on a wire mesh for 1 minute. Next, under conditions with an atmosphere of 20° C. and 65% relative humidity, the sample is set in a Tensilon tensile tester with a chuck spacing of 100 mm, and the sample is subjected to a tensile test at a pull rate of 100 mm/min, measuring the tensile strength (N) when the sample is torn.
[0124] As mentioned above, the multilayer sheet is obtained by drying of the wet tissue for 24 hours under conditions of 20±5° C., 65±5% RH, and vaporizing off the chemical solution from the wet tissue.
[0125] In the wet tissue of the present disclosure, the fiber density of the first hydrophobic fiber-containing layer is preferably higher than the fiber density of the first hydrophilic fiber-containing layer, and the fiber density of the second hydrophobic fiber-containing layer is preferably higher than the fiber density of the second hydrophilic fiber-containing layer. If the wet tissue of the present disclosure has layers of high fiber density (the first hydrophobic fiber-containing layer and second hydrophobic fiber-containing layer) in the middle, then substances to be wiped, such as feces, will be less likely to tear through the wet tissue when it is used. Furthermore, since a chemical solution can be held in the layers with high fiber density in the middle, the wet tissue is less likely to dry out.
[0126] The fiber density is calculated by dividing the basis weight of each layer (the first hydrophobic fiber-containing layer, second hydrophobic fiber-containing layer, first hydrophilic fiber-containing layer and second hydrophilic fiber-containing layer) by the thickness of each layer, and is compared.
[0127] The basis weight is calculated by dividing the mass of each layer that has been separated, by the area. The thickness is measured by immersing the first sheet (or second sheet) in liquid nitrogen and folding it in two, and observing the cross-section with a microscope.
[0128] In the wet tissue of the present disclosure, the mean fiber length of the fibers in the first sheet and second sheet, such as the hydrophobic fibers and hydrophilic fibers is not particularly restricted so long as it satisfies the aforementioned conditions with the spacing of the connected sections formed in the multilayer sheet, but the mean fiber length of the hydrophobic fibers and the mean fiber length of the hydrophilic fibers are preferably 6.5 mm or less, more preferably 6.0 mm or less, and even more preferably 5.5 mm or less. If the mean fiber length is greater than 6.5 mm, the absolute number of tangled points between the fibers in the first sheet and second sheet will increase, tending to lower the water disintegratability.
[0129] If the mean fiber length is longer, the absolute number of tangled points between the fibers will increase, thereby tending to lower the water disintegratability and increase the wet strength.
[0130] In the wet tissue of the present disclosure, each of the fibers in the first sheet and second sheet, for example, the hydrophobic fibers and hydrophilic fibers, and preferably the hydrophilic fibers other than pulp, has a mean fiber length of preferably 2.0 mm or greater, more preferably 2.5 mm or greater and even more preferably 3.0 mm or greater. If the mean fiber length is smaller than 2.0 mm, the wet strength of the first sheet and second sheet will be reduced, and the wet tissue may tear during use.
[0131] The multilayer sheet of the present disclosure, when containing no chemical solution, has a basis weight of preferably 30 to 90 g/m 2 , more preferably 40 to 80 g/m 2 , even more preferably 50 to 70 g/m 2 and yet more preferably 55 to 65 g/m 2 . If the basis weight is lower than 30 g/m 2 , the wet tissue may tear when the wet tissue is removed, and when the basis weight is greater than 90 g/m 2 , the user may feel hardness when using the wet tissue.
[0132] In the wet tissue of the present disclosure, each of the first sheet and the second sheet, when containing no chemical solution, has a basis weight of preferably 15 to 45 g/m 2 , more preferably 20 to 40 g/m 2 , even more preferably 25 to 35 g/m 2 and yet more preferably 27 to 33 g/m 2 . If the basis weight is lower than 15 g/m 2 , the water disintegratability will improve but the wet strength will tend to be reduced, and the bending resistance will tend to be lower. If the basis weight is higher than 45 g/m 2 , the wet strength will increase but the water disintegratability will tend to be reduced and the bending resistance will tend to be higher.
[0133] In the wet tissue of the present disclosure, the first hydrophobic fiber-containing layer and second hydrophobic fiber-containing layer, and the first hydrophilic fiber-containing layer and second hydrophilic fiber-containing layer, when containing no chemical solution, each have a basis weight of preferably 7 to 23 g/m 2 , more preferably 10 to 20 g/m 2 , even more preferably 12 to 18 g/m 2 and yet more preferably 13 to 17 g/m 2 .
[0134] In the wet tissue of the present disclosure, the multilayer sheet has a thickness of preferably 0.10 to 0.70 mm, more preferably 0.12 to 0.60 mm, even more preferably 0.14 to 0.50 mm and yet more preferably 0.16 to 0.40 mm. If the thickness is less than 0.10 mm, the water disintegratability of the wet tissue will improve but the wet strength will tend to be reduced, and the bending resistance will tend to be lower. If the thickness is greater than 0.70 mm, the wet strength of the wet tissue will increase but the water disintegratability will tend to be reduced, and the bending resistance will tend to be higher.
[0135] The thickness of the multilayer sheet is the thickness in the region of the multilayer sheet where the connected sections are not present.
[0136] In the wet tissue of the present disclosure, each of the first sheet and second sheet has, in the dry state, a thickness of preferably 0.05 to 0.35 mm, more preferably 0.06 to 0.30 mm, even more preferably 0.07 to 0.25 mm and yet more preferably 0.08 to 0.20 mm. If the thickness is less than 0.05 mm, the water disintegratability of the wet tissue will increase but the wet strength will tend to be reduced, and the bending resistance will tend to be lower. If the thickness is greater than 0.35 mm, the wet strength of the wet tissue will increase but the water disintegratability will tend to be reduced, and the bending resistance will tend to be higher.
[0137] The thickness of the first sheet and the second sheet is their thickness in the region where the connected sections are not present.
[0138] As mentioned above, the multilayer sheet is obtained by drying of the wet tissue for 24 hours under conditions of 20±5° C., 65±5% RH, and vaporizing off the chemical solution. Also, the first sheet and second sheet are obtained by detaching the first sheet and second sheet from the multilayer sheet.
[0139] The thicknesses of the first sheet and second sheet, and of the multilayer sheet, are measured using an FS-60DS by Daiei Kagaku Seiki Mfg. Co., Ltd., under the conditions, probe: 15 cm 2 , measuring load: 3 gf/cm 2 .
[0140] In a wet tissue according to another embodiment of the present disclosure, the first hydrophilic fiber-containing layer and the second hydrophilic fiber-containing layer are disposed on the surface layer of a multilayer sheet, the multilayer sheet having a ridge-furrow structure formed by spraying a high-pressure water jet onto one or both surfaces of the multilayer sheet.
[0141] FIG. 4 is a diagram illustrating such an embodiment, corresponding to a cross-sectional view along plane II-II of FIG. 1 . In the wet tissue 1 shown in FIG. 4 , the first hydrophilic fiber-containing layer 2 a and second hydrophilic fiber-containing layer 3 a are disposed on the surface layer of the multilayer sheet 4 , and the multilayer sheet 4 has a ridge-furrow structure including a plurality of ridges 8 and a plurality of furrows 9 formed by spraying a high-pressure water jet on both surfaces of the multilayer sheet 4 , and specifically the surface 10 ′ and surface 10 ″. If the wet tissue has a ridge-furrow structure as shown in FIG. 4 , the dirt removal property will be improved on both surfaces of the wet tissue.
[0142] The steps for forming ridges and furrows in the first sheet and/or second sheet will be explained under “Method of producing wet tissue”.
[0143] A wet tissue according to yet another embodiment of the present disclosure has a fold structure formed by crepe treatment of the first sheet and/or second sheet. By having a fold structure, the feel of the wet tissue on the skin will improve and the dirt removal property will improve.
[0144] The steps for forming a fold structure in the wet tissue will be explained under “Method of producing wet tissue”.
[0145] For the wet tissue of the present disclosure, chemical solutions with which the multilayer sheet may be impregnated include those used as chemical solutions for wet tissues in the technical field, and are not particularly restricted, with examples including aqueous solutions containing antimicrobial agents, detergents, antiseptic agents and the like, and the chemical solution may even be distilled water.
<Method of Producing Wet Tissue>
[0146] The method of producing the wet tissue of the present disclosure includes the following steps.
[0147] (1) A step of forming first sheet
[0148] (2) A step of forming second sheet
[0149] (3) A step of stacking the second sheet on the first sheet with the first hydrophobic fiber-containing layer and second hydrophobic fiber-containing layer facing each other, to form a stacked sheet, and connecting the stacked sheet to form a multilayer sheet having a plurality of connected sections.
[0150] The steps of (1) to (3) above will also be referred to as step (1) to step (3), respectively.
[0151] Step (1) can be further divided into the following steps.
[0152] (1a) A step of supplying an aqueous dispersion of a starting material for the first hydrophilic fiber-containing layer onto a support, and forming a web of the first hydrophilic fiber-containing layer on the support.
[0153] (1b) A step of spraying a high-pressure water jet onto the web of the first hydrophilic fiber-containing layer on the support from a high-pressure water jet nozzle, to tangle the fibers and form a first hydrophilic fiber-containing layer.
[0154] (1c) A step of supplying an aqueous dispersion of a starting material for the first hydrophobic fiber-containing layer onto a support, and forming a web of the first hydrophobic fiber-containing layer on the support.
[0155] (1d) A step of stacking the web of the first hydrophobic fiber-containing layer onto a surface of the first hydrophilic fiber-containing layer that has not been sprayed with the high-pressure water jet, and forming a water-including first sheet.
[0156] (1e) A step of drying the water-including first sheet.
[0157] The steps of (1a) to (1e) above will also be referred to as step (1a) to step (1e), respectively.
[0158] Step (2) can be further divided into the following steps.
[0159] (2a) A step of supplying an aqueous dispersion of a starting material for the second hydrophilic fiber-containing layer onto a support, and forming a web of the second hydrophilic fiber-containing layer on the support.
[0160] (2b) A step of spraying a high-pressure water jet onto the web of the second hydrophilic fiber-containing layer on the support from a high-pressure water jet nozzle, to tangle the fibers and form a second hydrophilic fiber-containing layer.
[0161] (2c) A step of supplying an aqueous dispersion of a starting material for the second hydrophobic fiber-containing layer onto a support, and forming a web of the second hydrophobic fiber-containing layer on the support.
[0162] (2d) A step of stacking the web of the second hydrophobic fiber-containing layer onto a surface of the second hydrophilic fiber-containing layer that has not been sprayed with the high-pressure water jet, and forming a water-including second sheet.
[0163] (2e) A step of drying the water-including second sheet.
[0164] The steps of (2a) to (2e) above will also be referred to as step (2a) to step (2e), respectively.
[0165] In step (1a) and step (2a), following a method known in the technical field, the aqueous dispersion of starting material for each of the first hydrophilic fiber-containing layer and second hydrophilic fiber-containing layer is supplied onto the support, forming the respective webs of the first hydrophilic fiber-containing layer and second hydrophilic fiber-containing layer on the support.
[0166] In step (1b) and step (2b), the web of each of the first hydrophilic fiber-containing layer and the web of the second hydrophilic fiber-containing layer is sprayed with a high-pressure water jet discharged from a high-pressure water jet nozzle, to form the first hydrophilic fiber-containing layer and second hydrophilic fiber-containing layer. The web of the first hydrophilic fiber-containing layer and the web of the second hydrophilic fiber-containing layer are subjected to energy of preferably 0.03 to 0.25 kW/m 2 , more preferably 0.04 to 0.20 kW/m 2 , even more preferably 0.05 to 0.15 kW/m 2 , yet more preferably 0.06 to 0.12 kW/m 2 , and even yet more preferably 0.07 to 0.10 kW/m 2 .
[0167] If the energy is lower than 0.03 kW/m 2 , the degree of intertangling of the fibers will be insufficient, tending to result in lower wet strength. Moreover if the energy is higher than 0.25 kW/m 2 , tangling of the fibers will progress, increasing the wet strength, but the water disintegratability will tend to be lower, and the bending resistance will tend to be higher.
[0168] The high-pressure water jet energy is calculated by the following formula.
[0000] High-pressure water jet energy (kW/m 2 )=1.63×spray pressure (kg/cm 2 )×spray flow rate (m 3 /min)/transport speed (M/min)/60
[0169] The value of the spray flow rate (m 3 /min) is calculated by the following formula.
[0000] Spray flow rate (m 3 /min)=750×orifice total open area (m 2 )×spray pressure (kg/cm 2 ) 0.495
[0170] The spray pressure is the pressure inside the nozzle at the point of spraying from the high-pressure water jet nozzles, the spray flow rate is the total flow per minute of the high-pressure water jet sprayed from the high-pressure water jet nozzles, and the orifice total open area is the total nozzle area of the high-pressure water jet nozzles.
[0171] The high-pressure water jet nozzle preferably has hole diameters of 70 to 130 μm. If the hole diameters are smaller than 70 μm the nozzle may tend to become clogged, and if the hole diameters are larger than 130 μm the efficiency of fiber tangling will tend to be reduced.
[0172] The high-pressure water jet nozzle pitch will generally be in the range of 0.3 to 1.0 mm.
[0173] The high-pressure water jet nozzle sprays the high-pressure water jet onto the web from a distance of preferably 0.5 to 3.0 cm, more preferably 0.5 to 2.0 cm and even more preferably 0.5 to 1.0 cm. If the spacing is less than 0.5 cm the web may tear, and if the spacing is greater than 3.0 cm the tangling of fibers in the web will tend to be insufficient.
[0174] In step (1c) and step (2c), following a method known in the technical field, the aqueous dispersion of the starting material for the first hydrophobic fiber-containing layer and the aqueous dispersion of the second hydrophobic fiber-containing layer are supplied onto the support, respectively forming a web of the first hydrophobic fiber-containing layer and a web of the second hydrophobic fiber-containing layer on the support.
[0175] In step (1d), the web of the first hydrophobic fiber-containing layer is stacked onto the surface of the first hydrophilic fiber-containing layer that has not been sprayed with the high-pressure water jet, and a water-including first sheet is formed. By stacking the first hydrophilic fiber-containing layer and the first hydrophobic fiber-containing layer before drying, the fibers contained therein become entangled, thereby connecting the first hydrophobic fiber-containing layer and the first hydrophilic fiber-containing layer.
[0176] From the viewpoint of the connecting strength between the first hydrophobic fiber-containing layer and the first hydrophilic fiber-containing layer, the first hydrophobic fiber-containing layer preferably further includes hydrophilic fibers. This is because in the subsequent step (1e), the hydrophilic fibers of the first hydrophobic fiber-containing layer and the hydrophilic fibers of the first hydrophilic fiber-containing layer form hydrogen bonds, and the first hydrophobic fiber-containing layer and first hydrophilic fiber-containing layer are become connected by them.
[0177] Step (2d) is similar to step (1d), and from the viewpoint of the connecting strength between the second hydrophobic fiber-containing layer and the second hydrophilic fiber-containing layer, the second hydrophobic fiber-containing layer preferably further includes hydrophilic fibers.
[0178] In step (1e) and step (2e), the sheet is dried by a method known in the technical field. The first sheet and second sheet are each preferably dried at a temperature that is lower, more preferably a temperature of at least 10° C. lower, even more preferably a temperature of at least 20° C. lower and yet more preferably a temperature of at least 30° C. lower than the melting point of the hydrophobic fibers. If the drying temperature is close to the melting point of the hydrophobic fibers, the hydrophobic fibers may melt during drying, and the hydrophobic fibers may fuse with the other fibers, lowering the water disintegratability of the wet tissue.
[0179] When the hydrophobic fibers include multiple components, the melting point is the lowest among the melting points of the multiple components.
[0180] When the first sheet includes heat-fusible fibers comprising composite fibers that include a low-melting-point component and a high-melting-point component, as the hydrophobic fibers, the first sheet is dried in step (1e) at a temperature that is preferably lower, more preferably a temperature of at least 10° C. lower, even more preferably a temperature of at least 20° C. lower and yet more preferably a temperature that is at least 30° C. lower, than the melting point of the low-melting-point component in the first sheet. If the drying temperature is close to the melting point of the low-melting-point component, the low-melting-point component may melt during drying, and the heat-fusible fibers may fuse with the other fibers, lowering the water disintegratability of the wet tissue.
[0181] The same applies when the second sheet includes heat-fusible fibers comprising composite fibers that include a low-melting-point component and a high-melting-point component as the hydrophobic fibers.
[0182] Incidentally, step (1e) and step (2e) can be carried out using a dryer known in the technical field, for example, a roll-type dryer, such as a yankee dryer. When a roll-type dryer is used to dry the first sheet, preferably the first sheet is dried in such a manner that the first hydrophobic fiber-containing layer does not contact with the roll of the roll-type dryer, or in other words, the first sheet is dried with the first hydrophilic fiber-containing layer contacting the roll of the roll-type dryer. This is in order to prevent fouling of the roll due to fusion of the hydrophobic fibers. The same applies for the second sheet as well.
[0183] In step (3), using a method known in the technical field, the second sheet is stacked on the first sheet with the first hydrophobic fiber-containing layer and second hydrophobic fiber-containing layer facing each other, to form a stacked sheet, and the stacked sheet is connected to form a multilayer sheet having a plurality of connected sections.
[0184] For example, in an embodiment in which the connected sections are embossed sections and the hydrophobic fibers are heat-fusible fibers comprising composite fibers that include a low-melting-point component and a high-melting-point component, preferably the stacked sheet is embossed at a temperature of at least the melting point of the low-melting-point component and below the melting point of the high-melting-point component, more preferably the stacked sheet is embossed at a temperature of at least 10° C. higher than the melting point of the low-melting-point component and more than 10° C. below the melting point of the high-melting-point component, even more preferably the stacked sheet is embossed at a temperature of at least 20° C. higher than the melting point of the low-melting-point component and more than 20° C. below the melting point of the high-melting-point component, and even yet more preferably the stacked sheet is embossed at a temperature of at least 30° C. higher than the melting point of the low-melting-point component and more than 30° C. below the melting point of the high-melting-point component.
[0185] If the embossing temperature is close to the melting point of the low-melting-point component, melting of the low-melting-point component will be insufficient, and connection between the first sheet and second sheet will also be sufficient, or the time for the embossing step will tend to be longer. If the embossing temperature is close to the melting point of the high-melting-point component, the high-melting-point component will melt and the embossed sections may become hard.
[0186] For example, when the connected sections are adhesive sections or pressure-sensitive adhesive sections, the adhesive or pressure-sensitive adhesive may be coated on the first hydrophobic fiber-containing layer and/or second hydrophobic fiber-containing layer, and the first sheet may be stacked on the second sheet with the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer facing each other, connecting the first sheet and second sheet to form a multilayer sheet.
[0187] The method of producing the wet tissue of the present disclosure may include, after step (3), the following step:
[0188] (4) a step of impregnating the multilayer sheet with a chemical solution.
[0189] The step of (4) above will also be referred to as step (4).
[0190] In step (4), the multilayer sheet is impregnated with a chemical solution by a method known in the technical field.
[0191] A method of producing the wet tissue of the present disclosure will now be explained with reference to the drawings.
[0192] FIG. 5 is a schematic diagram for illustration of a method of producing a wet tissue according to one embodiment of the present disclosure, and specifically of step (1) and step (2).
[0193] In the production apparatus 101 shown in FIG. 5 , an aqueous dispersion of the starting material for the first hydrophilic fiber-containing layer is supplied onto a support 103 from a starting material supply head 102 , and a web 104 of the first hydrophilic fiber-containing layer is formed on the support 103 .
[0194] Next, the web 104 is dewatered with a suction box 107 , and the web 104 is passed between two high-pressure water jet nozzles 105 disposed over the support 103 , and two suction boxes 107 that collect water sprayed from the high-pressure water jet nozzles 105 , disposed at locations facing the high-pressure water jet nozzles 105 in a manner sandwiching the support 103 . During passage, the web 104 receives a high-pressure water jet from the high-pressure water jet nozzle 105 , tangling the fibers together and forming a first hydrophilic fiber-containing layer 106 that contains water.
[0195] Depending on the spacing of the high-pressure water jet nozzles 105 , the energy received from the high-pressure water jets, etc., ridges and furrows will sometimes be formed on the surface of the first hydrophilic fiber-containing layer 106 facing the high-pressure water jet nozzles 105 .
[0196] Concomitantly with formation of the first hydrophilic fiber-containing layer 106 , an aqueous dispersion of the starting material for the first hydrophobic fiber-containing layer is supplied onto the support 113 from a starting material supply head 112 , and a web 114 of the first hydrophobic fiber-containing layer is formed on the support 113 . Next, the web 114 is dewatered by a suction box 117 and the dewatered web 114 is transferred onto a transport conveyor 121 .
[0197] The web 114 of the first hydrophobic fiber-containing layer transported by the transport conveyor 121 is then stacked on the first hydrophilic fiber-containing layer 106 to form a first sheet 122 .
[0198] Next, the first sheet 122 is transferred to the transport conveyor 123 , after which it is transferred to a dryer 124 . The dryer 124 may be a yankee dryer, for example. The dried first sheet 122 is then wound onto a wind-up roll 125 .
[0199] The second sheet can be produced using the production apparatus 101 shown in FIG. 5 , similar to the first sheet, and therefore it will not be explained here. By adjusting the starting material composition and starting material supply rate for production, it is possible to adjust the fiber composition, basis weight, etc. of the second sheet.
[0200] FIG. 6 is a schematic diagram for illustration of a method of producing a wet tissue according to one embodiment of the present disclosure, and specifically of step (3) and step (4).
[0201] In the production apparatus 101 ′ shown in FIG. 6 , the second sheet 127 wound out from the wind-up roll 126 is stacked onto the first sheet 122 wound out from the wind-up roll 125 , with the first hydrophobic fiber-containing layer (not shown) and the second hydrophobic fiber-containing layer (not shown) facing each other, to form the stacked sheet 128 .
[0202] The stacked sheet 128 is then passed between a pair of embossing rolls 129 that are heated, to form a multilayer sheet 130 having a plurality of embossed sections (not shown). In the multilayer sheet 130 , a plurality of embossed sections (not shown) are formed connecting the first hydrophobic fiber-containing layer (not shown) and second hydrophobic fiber-containing layer (not shown).
[0203] The multilayer sheet 130 is then cut to a prescribed size and the cut sheet is folded and impregnated with a chemical solution to complete the wet tissue.
[0204] The method of producing a wet tissue according to yet another embodiment of the present disclosure further includes a step of crepe treatment of the first sheet and/or second sheet. By performing crepe treatment, the wet tissue will have a fold structure, providing effects, such as improved dirt removability and improved feel on the skin.
[0205] The step of crepe treatment of the first sheet is preferably carried out after step (1e). The step of crepe treatment of the second sheet is also preferably carried out after step (2e).
[0206] The crepe treatment is carried out, for example, at the dryer 124 shown in FIG. 5 , by pulling the first sheet 122 , which is adhered to the surface of the dryer 124 , off from the surface using a doctor blade.
[0207] The wet tissue of the present disclosure can also be produced by steps known in the prior art, such as a combination of the steps described in Japanese Unexamined Patent Publication No. 2012-202004, Japanese Unexamined Patent Publication No. 2012-20211 and Japanese Unexamined Patent Publication No. 2013-76196, for example.
EXAMPLES
[0208] The present disclosure will now be explained in fuller detail by examples, with the understanding that it is not meant to be limited to the examples.
[Starting Materials]
[Hydrophilic Fibers]
[0209] Non-Beaten Pulp
[0210] Northern bleached Kraft pulp (NBKP, CSF: 740 mL) was prepared.
[0211] Beaten Pulp
[0212] The Northern bleached Kraft pulp was mixed with a mixer to obtain beaten pulp having a CSF of 600 mL.
[0213] Rayon (A)
[0214] Corona (mean fiber length: 5 mm, 0.7 dtex) by Daiwabo Rayon Co., Ltd. was prepared.
[0215] Rayon (B)
[0216] Rayon (mean fiber length: 7 mm, 0.7 dtex) by OmiKenshi Co., Ltd. was prepared.
[Hydrophobic Fibers]
[0217] Heat-Fusible Fibers
[0218] Core-sheath composite fibers (trade name: Tepilus, type: TJ04BN, cut length: 5 mm, 2.2 dtex) by Teijin, Ltd. were prepared. The core was PET with a melting point of 265° C., and the sheath was terephthalate-based fiber with a melting point of 150° C.
Production Example 1
[0219] Aqueous dispersion No. 1 as the starting material for the first hydrophilic fiber-containing layer, containing 70 parts by mass of beaten pulp and 30 parts by mass of rayon (A), was prepared. In the production apparatus shown in FIG. 5 , aqueous dispersion No. 1 as the starting material for the first hydrophilic fiber-containing layer was supplied onto the support (OS80 by Nippon Filcon Co., Ltd.) from the starting material supply head, and dewatering was carried out from a suction box to form web No. 1 of the first hydrophilic fiber-containing layer.
[0220] Next, a high-pressure water jet was sprayed onto web No. 1 of the first hydrophilic fiber-containing layer from a high-pressure water jet nozzle, while suctioning the water by suction from below the support, to obtain first hydrophilic fiber-containing layer No. 1. The high-pressure water jet nozzles were situated at a distance of about 2 cm from above web No. 1 for the first sheet, and they had hole diameters of 92 μm and hole pitches of 0.5 mm. The energy received by the high-pressure water jet was 0.088 (KW/m 2 ).
[0221] Concomitant with production of web No. 1 for the first hydrophilic fiber-containing layer, aqueous dispersion No. 1 was prepared as the starting material for the first hydrophobic fiber-containing layer, containing 60 parts by mass of beaten pulp, 32 parts by mass of non-beaten pulp and 8 parts by mass of heat-fusible fiber. In the production apparatus shown in FIG. 5 , aqueous dispersion No. 1 as the starting material for the first hydrophobic fiber-containing layer was supplied onto the support (OS80 by Nippon Filcon Co., Ltd.) from the starting material supply head, and dewatering was carried out from a suction box to form web No. 1 of the first hydrophobic fiber-containing layer.
[0222] Web No. 1 for the hydrophobic fiber-containing layer was stacked over hydrophilic fiber-containing layer No. 1, to form first sheet No. 1 containing water, and first sheet No. 1 was dried for about 4 seconds with a yankee dryer kept at 120° C. The dried first sheet No. 1 had hydrophobic fiber-containing layer No. 1 and hydrophilic fiber-containing layer No. 1 connected by hydrogen bonding, for example.
[0223] Second sheet No. 1 was obtained by the same production method as for first sheet No. 1.
[0224] Second sheet No. 1 was stacked onto first sheet No. 1 with the first hydrophobic fiber-containing layer No. 1 and second hydrophobic fiber-containing layer No. 1 facing each other, to form stacked sheet No. 1, and then the stacked sheet No. 1 was passed through a pair of embossing rolls that had been heated to 160° C., to form multilayer sheet No. 1 having a plurality of embossed sections. The pair of embossing rolls had rotational axis lines in the direction perpendicular to the machine direction, and had protrusions with diameters of 2.2 mm disposed on the outer peripheral surface of the upper roll in a square zigzag fashion at a pitch of 20 mm in the machine direction and 20 mm in the cross-machine direction, while the surface of the lower roll was flat.
[0225] Multilayer sheet No. 1 had embossed sections with diameters of 2.2 mm (area: approximately 3.8 mm 2 ) arranged in a square zigzag fashion at a pitch of 20 mm in the machine direction and 20 mm in the cross-machine direction, the spacing of the embossed sections was approximately 12 mm, and the embossed sections had an area ratio of 1.7% with respect to the multilayer sheet.
[0226] Multilayer sheet No. 1 was cut to approximately 20 cm×13 cm and impregnated with a chemical solution to produce wet tissue No. 1.
Comparative Production Example 1
[0227] A wet tissue was produced according to the method described in PTL 5. Specifically, 26 parts by mass of beaten pulp (CSF: 600 mL), 50 parts by mass of non-beaten pulp (CSF: 740 mL), 21 parts by mass of rayon (B) and 3 parts by mass of fibrillated cellulose fiber were mixed together with water, and a square sheet machine was used to produce a fiber web by a wet paper forming method.
[0228] The fiber web was placed on a 100 mesh plastic net, and the fiber web was sprayed with a high-pressure water jet from high-pressure water jet nozzles (nozzle diameter: 92μ, 0.5 mm pitch) while suctioning off the water by suction from below, after which it was dried with a rotary dryer to obtain sheet No. 2. Sheet No. 2 was impregnated with a chemical solution to obtain wet tissue No. 2. The energy received by the high-pressure water jet was 0.285 (KW/m 2 ).
[0229] Incidentally, the fibrillated cellulose fiber was prepared by wet beating Tencel (trade name of Lenzing (Austria), mean fiber length: 3 mm, 1.7 dtex) with a batch macerator (pulper by Aikawa Iron Works Co.) and a continuous macerator (B-type Top Finer by Aikawa Iron Works Co.), and the fiber length in the peak of the weight-weighted average fiber length distribution of the fibrillated cellulose was 3 mm, the mass of the microfiber portion was 1.54 mass %, and the Canadian Standard Freeness was 200 mL.
Example 1 and Comparative Example 1
[0230] The physical properties of the first sheets, second sheets, multilayer sheets and wet tissues produced in Production Example 1 and Comparative Production Example 1 were evaluated.
[0231] The results are shown in Table 1.
[0232] In Table 1, the “basis weight” was calculated by dividing the mass of the sheet by the area.
[0233] The “thickness” was measured using an FS-60DS by Daiei Kagaku Seiki Mfg. Co., Ltd. (probe: 15 cm 2 , measuring load: 3 gf/cm 2 ), and the mean value of the thickness at 3 locations was used.
[0234] The “wet strength” for the wet tissue was measured by the method described in the present specification, and for the first sheet and second sheet it was measured in the same manner as for the wet tissue, after allowing the sheet to absorb 250 mass % of distilled water. The tensile strength was measured using an AGS-1kNG autograph by Shimadzu Corp.
[0235] The “disintegratability” was measured by the method described in the present specification. For the first sheet and second sheet, the first sheet and second sheet were separated after embossing was formed in the multilayer sheet, and were supplied to a disintegration test. For the wet tissue, it was supplied directly to the disintegration test. The disintegratability was measured using a TTP stirrer for paper disintegration testing, by As One Corp.
[0236] The “bending resistance” was measured by the method described in the present specification.
[0237] In Table 1, the indication “wet” is for samples measured while containing chemical solution or distilled water, while “dry” is for samples measured without containing chemical solution or distilled water.
[0000]
TABLE 1
Example No.
Comp.
Example 1
Example 1
First sheet and second sheet
Sheet No.
No. 1
No. 2
Sheet type
First
Second
—
Fiber-containing layer
Hydrophilic
Hydrophobic
Hydrophilic
Hydrophobic
—
Beaten pulp (parts)
70
60
70
60
26
Non-beaten pulp (parts)
—
32
—
32
50
Rayon (A) (parts)
30
—
30
—
—
Rayon (B) (parts)
—
—
—
—
21
Heat-fusible fiber (parts)
—
8
—
8
—
Fibrillated cellulose
—
—
—
—
3
fiber (parts)
High-pressure water
0.088
—
0.088
—
0.285
jet energy (kW/m 2 )
Dry basis weight (g/m 2 )
14.2
15.0
14.2
15.0
—
Dry thickness (mm)
0.12
0.12
—
Wet strength
Machine
0.8
—
(N/25 mm)
direction
Cross-
0.6
—
machine
direction
Disintegratability
Seconds
71
—
Multilayer sheet or wet tissue
Embossed sections
Shape
Circular
—
Spacing
12
—
(mm)
Area
3.8
—
(mm 2 )
Area
1.7
—
ratio (%)
Number
4.850
—
density
(num/m 2 )
Embossing spacing/rayon
2.4
—
mean fiber length
Dry basis weight (g/m 2 )
58.4
50.0
Dry thickness (mm)
0.25
0.30
Wet strength
Machine
1.6
3.2
(N/25 mm)
direction
Cross-
1.3
1.4
machine
direction
Disintegratability
Seconds
201
285
Dry bending
Machine
145
135
resistance
direction
(mm)
Cross-
95
60
machine
direction
[0238] Table 1 shows that in Example 1, the tensile strength of the wet tissue in the machine direction and cross-machine direction was greater than 1.0 N/25 mm, while the disintegratability of the first sheet and second sheet was less than 100 seconds, indicating that both wet strength and water disintegratability had been obtained.
Reference Production Example 1
[0239] Starting material No. 1 for a first sheet was prepared containing 45 parts by mass of beaten pulp, 32 parts by mass of non-beaten pulp, 15 parts by mass of rayon (A) and 8 parts by mass of heat-fusible fibers. In the production apparatus shown in FIG. 5 , starting material No. 1 for the first sheet was supplied onto the support (OS80 by Nippon Filcon Co., Ltd.) from the starting material supply head, and dewatering was carried out from the suction boxes to form web No. 11 for the first sheet.
[0240] Next, a high-pressure water jet was sprayed onto web No. 11 for the first sheet from the high-pressure water jet nozzles, while suctioning the water with a suction from below the support, to obtain first sheet No. 11. The high-pressure water jet nozzles were situated at a distance of about 2 cm from above web No. 11 for the first sheet, and they had hole diameters of 92 μm and hole pitches of 0.5 mm. The energy received by the high-pressure water jets was 0.088 (KW/m 2 ).
[0241] Next, first sheet No. 11 was dried for approximately 4 seconds with a yankee dryer kept at 120° C.
[0242] Second sheet No. 11 was obtained by the same production method as for first sheet No. 11.
[0243] Second sheet No. 11 was stacked onto first sheet No. 11 to form stacked sheet No. 11, and then stacked sheet No. 11 was passed through a pair of embossing rolls that had been heated to 160° C., to form multilayer sheet No. 11 having a plurality of embossed sections. The pair of embossing rolls were identical to those used in Production Example 1.
[0244] Multilayer sheet No. 1 was cut to approximately 20 cm×approximately 13 cm and impregnated with a chemical solution to produce wet tissue No. 1.
Reference Production Example 2
[0245] First sheet No. 12, second sheet No. 12, multilayer sheet No. 12 and wet tissue No. 12 were produced in the same manner as Reference Production Example 1, except that the upper roll of the pair of embossing rolls was changed to one having protrusions with diameters of 0.88 mm arranged in a 60° zigzag pattern with a pitch of 4.5 mm in the cross-machine direction.
[0246] Multilayer sheet No. 12 had embossed sections with diameters of 0.88 mm (area: approximately 0.6 mm 2 ) arranged in a 60° zigzag fashion at a pitch of 4.5 mm in the cross-machine direction, the spacing of the embossed sections being approximately 3.6 mm, and the embossed sections having an area ratio of 3.4% with respect to the multilayer sheet.
Reference Production Example 3
[0247] First sheet No. 13, second sheet No. 13, multilayer sheet No. 13 and wet tissue No. 13 were produced in the same manner as Reference Production Example 1, except that the upper roll of the pair of embossing rolls was changed to one having on the outer peripheral surface protrusions with widths of 1.5 mm protruding in the direction perpendicular to the rotational axis line, arranged continuously at a pitch of 10 mm.
[0248] Multilayer sheet No. 13 had embossed sections with widths of 1.5 mm, extending in the machine direction, arranged in a striped fashion at a pitch of 10 mm in the cross-machine direction, the spacing between the embossed sections being 8.5 mm, and the embossed sections having an area ratio of 15% with respect to the multilayer sheet.
Reference Examples 1 to 3
[0249] The physical properties of the first sheets, second sheets, multilayer sheets and wet tissues produced in Reference Production Examples 1 to 3 were evaluated.
[0250] The results are shown in Table 2.
[0000]
TABLE 2
Reference example No.
Reference
Reference
Reference
Example 1
Example 2
Example 3
First sheet and second sheet
Sheet No.
No. 11
No. 12
No. 13
First sheet/second sheet
First
Second
First
Second
First
Second
Beaten pulp (parts)
45
45
45
45
45
45
Non-beaten pulp (parts)
32
32
32
32
32
32
Rayon (A) (parts)
15
15
15
15
15
15
Heat-fusible fiber (parts)
8
8
8
8
8
8
High-pressure water
0.088
0.088
0.088
0.088
0.088
0.088
jet energy (kW/m 2 )
Dry basis weight (g/m 2 )
25.3
25.3
25.3
25.3
25.3
25.3
Dry thickness (mm)
0.16
0.16
0.16
0.16
0.16
0.16
Wet strength
Machine direction
0.9
1.2
1.2
(N/25 mm)
Cross-machine
0.6
0.9
0.7
direction
Disintegratability
Seconds
41
73
104
Multilayer sheet or wet tissue
Embossed sections
Shape
Circular
Circular
Stripe
Spacing (mm)
12
3.6
8.5
Area (mm 2 )
3.8
0.6
—
Area ratio (%)
1.7
3.4
15
Number density
4,850
50,000
100
(num/m 2 )
Embossing spacing/rayon
2.40
0.72
1.70
mean fiber length
Dry basis weight (g/m 2 )
50.6
50.6
50.6
Dry thickness (mm)
0.31
0.30
0.30
Wet strength
Machine direction
1.6
1.9
2.0
(N/25 mm)
Cross-machine
1.1
1.6
1.1
direction
Disintegratability
Seconds
88
176
320
Dry bending
Machine direction
134
140
175
resistance (mm)
Cross-machine
85
72
75
direction
[0251] While not direct examples of the present invention, Table 2 suggests that the water disintegratability is excellent even when the embossing spacing is shorter than the rayon mean fiber length. Furthermore, Table 2 suggests that the water disintegratability is excellent even when the area ratio of the adhesive sections is high.
[0252] Specifically, the present disclosure relates to the following aspects J1 to J16.
[J1]
[0253] A wet tissue with water disintegratability, including a multilayer sheet comprising a first sheet and a second sheet, wherein
[0254] the first sheet includes a first hydrophilic fiber-containing layer including hydrophilic fibers at 95 to 100 mass % and a first hydrophobic fiber-containing layer including hydrophobic fibers at 5 to 30 mass %, and the second sheet includes a second hydrophilic fiber-containing layer including hydrophilic fiber at 95 to 100 mass % and a second hydrophobic fiber-containing layer including hydrophobic fiber at 5 to 30 mass %,
[0255] the first hydrophobic fiber-containing layer being disposed adjacent to the second hydrophobic fiber-containing layer,
[0256] the multilayer sheet having a plurality of connected sections, disposed across spacings, where the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer are connected,
[0257] the spacings between the plurality of connected sections being 0.6 times or above the mean fiber length of the hydrophobic fibers of the first hydrophobic fiber-containing layer and 0.6 times or above the mean fiber length of the hydrophobic fibers of the second hydrophobic fiber-containing layer,
[0258] the plurality of connected sections having an area ratio of 0.5 to 12.0% with respect to the multilayer sheet,
[0259] each of the first sheet and second sheet, which is separated from the multilayer sheet, having a disintegratability of 100 seconds or less in a disintegration test,
[0260] the multilayer sheet having a bending resistance of 150 mm or less, and
[0261] the wet tissue having a tensile strength of 1.0N or greater per 25 mm width.
[J2]
[0262] The wet tissue according to J1, wherein a fiber density of the first hydrophobic fiber-containing layer is higher than a fiber density of the first hydrophilic fiber-containing layer, and/or a fiber density of the second hydrophobic fiber-containing layer is higher than a fiber density of the second hydrophilic fiber-containing layer.
[J3]
[0263] The wet tissue according to J1 or J2, wherein the first hydrophilic fiber-containing layer and the second hydrophilic fiber-containing layer are disposed on the surface layer of the multilayer sheet, the multilayer sheet having a ridge-furrow structure formed by spraying a high-pressure water jet on one or both surfaces of the multilayer sheet.
[J4]
[0264] The wet tissue according to any one of J1 to J3, wherein each of the first hydrophobic fiber-containing layer and second hydrophobic fiber-containing layer includes, as the hydrophobic fibers, heat-fusible fibers consisting of composite fibers that include a low-melting-point component and a high-melting-point component having a higher melting point than the low-melting-point component.
[J5]
[0265] The wet tissue according to J4, wherein each of the plurality of the connected sections is an embossed section, and in the embossed section, at least some of the low-melting-point component of the hydrophobic fibers of the first hydrophobic fiber-containing layer are fused with the fibers in the second hydrophobic fiber-containing layer, and/or at least some of the low-melting-point component of the hydrophobic fibers of the second hydrophobic fiber-containing layer are fused with the fibers in the first hydrophobic fiber-containing layer.
[J6]
[0266] The wet tissue according to any one of J1 to J5, wherein the hydrophobic fibers of the first hydrophobic fiber-containing layer and/or the hydrophobic fibers of the second hydrophobic fiber-containing layer have a mean fiber length of 6.5 mm or less.
[J7]
[0267] The wet tissue according to any one of J1 to J6, wherein each of the plurality of connected sections has an area of 0.4 to 9 mm 2 .
[J8]
[0268] The wet tissue according to any one of J1 to J7, wherein each of the first hydrophilic fiber-containing layer and second hydrophilic fiber-containing layer includes hydrophilic fibers at 100 mass %, and each of the first hydrophobic fiber-containing layer and second hydrophobic fiber-containing layer includes hydrophobic fibers at 5 to 30 mass % and hydrophilic fibers at 70 to 95 mass %.
[J9]
[0269] The wet tissue according to any one of J1 to J8, wherein the hydrophilic fibers of the first hydrophilic fiber-containing layer and/or the hydrophilic fibers of the second hydrophilic fiber-containing layer include pulp and regenerated cellulose.
[J10]
[0270] The wet tissue according to any one of J1 to J9, wherein the wet tissue has a fold structure formed by crepe treatment of the first sheet and/or second sheet.
[J11]
[0271] A method of producing the wet tissue according to any one of J1 to J10, the method including the steps of:
[0272] (1) forming the first sheet;
[0273] (2) forming the second sheet; and
[0274] (3) stacking the second sheet onto the first sheet with the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer facing each other, to form a stacked sheet, and connecting the stacked sheet to form a multilayer sheet having a plurality of connected sections.
[J12]
[0275] The method according to J11, wherein step (1) further includes the steps of:
[0276] (1a) supplying an aqueous dispersion of a starting material for the first hydrophilic fiber-containing layer onto a support, and forming a web of the first hydrophilic fiber-containing layer on the support;
[0277] (1b) spraying the web of the first hydrophilic fiber-containing layer on the support with a high-pressure water jet from a high-pressure water jet nozzle to tangle the fibers, and form a first hydrophilic fiber-containing layer;
[0278] (1c) supplying an aqueous dispersion of a starting material for the first hydrophobic fiber-containing layer onto a support, and forming a web of the first hydrophobic fiber-containing layer on the support;
[0279] (1d) stacking the web of the first hydrophobic fiber-containing layer onto a surface of the first hydrophilic fiber-containing layer that has not been sprayed with the high-pressure water jet, and forming a water-including first sheet; and
[0280] (1e) drying the water-including first sheet.
[J13]
[0281] The method according to J11 or J12, wherein step (2) further includes the steps of:
[0282] (2a) supplying an aqueous dispersion of a starting material for the second hydrophilic fiber-containing layer onto a support, and forming a web of the second hydrophilic fiber-containing layer on the support;
[0283] (2b) spraying the web of the second hydrophilic fiber-containing layer on the support with a high-pressure water jet from a high-pressure water jet nozzle to tangle the fibers, and form a second hydrophilic fiber-containing layer;
[0284] (2c) supplying an aqueous dispersion of a starting material for the second hydrophobic fiber-containing layer onto a support, and forming a web of the second hydrophobic fiber-containing layer on the support;
[0285] (2d) stacking the web of the second hydrophobic fiber-containing layer onto a surface of the second hydrophilic fiber-containing layer that has not been sprayed with the high-pressure water jet, and forming a water-including second sheet; and
[0286] (2e) drying the water-including second sheet.
[J14]
[0287] The method according to any one of J11 to J13, wherein each of the first hydrophobic fiber-containing layer and the second hydrophobic fiber-containing layer include, as hydrophobic fibers, heat-fusible fibers consisting of composite fibers including a low-melting-point component and a high-melting-point component having a higher melting point than the low-melting-point component, in step (1), the water-including first sheet is dried at a temperature lower than the melting point of the low-melting-point component of the hydrophobic fibers in the first hydrophobic fiber-containing layer, and in step (2), the water-including second sheet is dried at a temperature lower than the melting point of the low-melting-point component of the hydrophobic fibers in the second hydrophobic fiber-containing layer.
[J15]
[0288] The method according to J14, wherein in step (3), the stacked sheet is embossed at a temperature at or above the melting point of the low-melting-point component of the hydrophobic fibers in the first hydrophobic fiber-containing layer and the low-melting-point component of the hydrophobic fibers in the second hydrophobic fiber-containing layer, and below the melting point of the high-melting-point component of the hydrophobic fibers in the first hydrophobic fiber-containing layer and the high-melting-point component of the hydrophobic fibers in the second hydrophobic fiber-containing layer, to form a multilayer sheet having a plurality of connected sections.
[J16]
[0289] The method according to J12, wherein in step (1e), the water-including first sheet is dried while contacting the first hydrophilic fiber-containing layer with a roll of a roll-type dryer.
[J17]
[0290] The method according to J13, wherein in step (2e), the water-including second sheet is dried while contacting the second hydrophilic fiber-containing layer with a roll of a roll-type dryer.
[J18]
[0291] The method according to any one of J11 to J17, wherein step (1) further includes a step of crepe treatment of the first sheet, and/or step (2) further includes a step of crepe treatment of the second sheet.
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The purpose of the present disclosure is to provide a wet wipe which achieves both wet-strength and water-dissolvability. The wet wipe comprises the following configuration. This water-dissolving wet wipe comprises a multi-layer sheet provided with a first sheet and a second sheet, said wet wipe being characterized in that: the first sheet comprises a first hydrophilic fiber-containing layer and a first hydrophobic fiber-containing layer, and the second sheet comprises a second hydrophilic fiber-containing layer and a second hydrophobic fiber-containing layer; the multi-layer sheet has a plurality of junction parts at predetermined intervals; the plurality of junction parts occupy 0.5% to 12.0% of the surface area; the first sheet and the second sheet each have a separability of less than or equal to 100 seconds; the multi-layer sheet has a bending resistance of less than or equal to 150 mm; and the wet wipe has a tensile strength of greater than or equal to 1.0 N/25 mm.
| 3
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FIELD OF INVENTION
[0001] The present invention relates broadly to a charge pump circuit and to a method for compensating current mismatch in a charge pump circuit.
BACKGROUND
[0002] A charge pump is an electronic circuit that uses switches to control the connections of voltages to double voltages, invert voltages, or generate arbitrary voltages, depending on the controller and circuit topology. An example for a charge pump circuit application is in phase locked loop circuits (PLL). For designing a charge pump circuit, an important objective is to minimize the mismatch between “up” (pull-up) and “down” (pull-down) currents. In an integer-N synthesizer, the current mismatch will cause the charge pump's output spectrum to have a higher reference spur. For fractional-N synthesizer, the current mismatch will cause an extra problem, known as higher in-band phase noise.
[0003] FIG. 1 shows an existing charge pump circuit that attempts to deal with the mismatch problem between currents “up” and “down”. In this circuit, the original current source I_bias is mirrored to a common current branch for presenting “up” (I_up) and “down” (I_down) currents to N-MOS transistor M 1 and P-MOS transistor M 2 respectively. Between these two current carrying transistors (M 1 , M 2 ), there are four trans-gate switches (S 1 , S 2 , S 3 and S 4 ) of the same size and they form the current branch 101 (S 1 and S 2 ) parallel to a dummy branch 100 (S 3 and S 4 ). Each branch has its two trans-gate switches serially connected. The charge pump output voltage V_ds is taken at the CP_out point between S 1 and S 2 and a reference voltage V_ref is taken between S 3 and S 4 . Linking charge pump output (V_ds) and the voltage reference V_ref, a negative feedback is formed via an Operational Amplifier (Op) so that the voltage value V_ref follows V_ds. In these branches, D and U are digital signals from a phase frequency detector (PFD) to control the trans-gate switches (S 1 to S 4 ) so that the pumping of the positive and negative current (CP_out) is regulated. In this circuit, a charge injection is minimized by implementing the identical switches (S 1 to S 4 ) with a minimal size and the possible overlap charge injection is reduced by fine-tuning the size of current carrying transistors (M 1 , M 2 ). During operation, M 1 and M 2 are not switched on or off to prevent current switching effects on the drain of the current sources. When the charge pump is off i.e. both S 1 and S 2 are closed, the current is diverted into a dummy current branch 100 via S 3 and S 4 .
[0004] In the charge pump circuit, there exists a systematic current variation due transistor mismatch between M 1 and M 2 . Consequently, the resulting current mismatch of the charge pump circuit is in practice difficult to avoid.
[0005] Referring to FIG. 2 , the simulation result for the charge pump circuit of FIG. 1 is shown. The vertical axis represents the electric current value and the horizontal axis gives the reference voltage V_ref (0˜1.8V) value, which follows the charge pump output voltage V_ds. The current passing through M 1 (100 μA) is marked with I_up (curve 200 ) and the current passing through M 2 (−95 μA) is marked with I_down (curve 202 ). The current mismatch is illustrated by the current mismatch curve 204 . It can be observed that the circuit is not able to compensate the current mismatch and resulted current mismatch is quite large.
[0006] Another existing charge pump circuit is illustrated in FIG. 3 . The charge pump connects an original current source (I_bias) with a feedback network portion 300 , a core charge pump portion 302 and a replica bias portion 304 . This circuit uses the replica bias circuit 304 to equalize up and down currents regardless of the charge pump's output voltage V_ds. However, the voltage range V_ds of this charge pump is narrow which inhibits the feedback loop from operating properly. Such charge pump circuits cannot have good current match and are limited in terms of dynamic voltage range.
[0007] There are some charge pump circuits using digital circuits to control current mismatch. However, the digital circuit has to be turned on at all times to achieve good current match, which causes problems to the charge pump circuit.
[0008] A need therefore exists for compensating current mismatch in a charge pump circuit that seeks to address at least one of the above problems.
SUMMARY
[0009] In accordance with a first aspect for the present invention there is provided a charge pump circuit comprising a core charge pump circuit; a replica charge pump circuit for sensing a current mismatch in the core charge pump circuit and for converting the sensed current mismatch into a voltage signal V_ctrl; wherein V-ctrl is utilised for compensating the current mismatch in the core charge pump circuit.
[0010] The core charge pump circuit may include a first n-type transistor and a first p-type transistor, parallel first and second branches between respective drains of the first n-type and the first p-type transistor, each branch including two switch elements, and a voltage follower circuit connected between a V_ref input point and a CP_out point between the switch elements on the first and second branches respectively;
[0011] the replica charge pump circuit may include a second n-type transistor and a second n-type transistor, two switch elements of the same type as the switch elements of the core charge pump circuit connected in series between the drains of the second n-type and the second p-type transistor; and a feedback loop with one input taken from a point between the two switch elements of the replica charge pump circuit and V_ref supplied to another input of the feedback loop and V-ctrl as the output of the feedback loop.
[0012] The charge pump circuit may further comprise a first current compensating circuit for converting V_ctrl into a compensating “up” current, and a second current compensating circuit for converting V_ctrl into a compensating “down” current.
[0013] The compensating “up” current may be supplied to the drains of the first and second n-type transistors, and the compensating “down” current is supplied to the drains of the first and second p-type transistors.
[0014] The first and second compensating circuits may comprise respective differential circuits for converting a voltage difference between V_ref and V_ctrl into the compensating “up” and “down” currents respectively.
[0015] The switch elements may comprise trans-gate switches.
[0016] Current mismatch may be substantially compensated over a range of more than about 1V in variation of V_ref.
[0017] In accordance with a second aspect of the present invention there is provided a method of compensating current mismatch in a charge pump circuit, the method comprising sensing the current mismatch in the charge pump circuit; converting the sensed current mismatch into a voltage signal V_ctrl; and utilising V-ctrl to compensate the current mismatch.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Embodiments of the invention will be better understood and readily apparent to one of ordinary skill in the art from the following written description, by way of example only, and in conjunction with the drawings, in which:
[0019] FIG. 1 shows a circuit diagram of an existing charge pump circuit for compensating up and down current mismatch;
[0020] FIG. 2 shows a simulation result for the current mismatch of the charge pump circuit of FIG. 1 ;
[0021] FIG. 3 shows another existing charge pump circuit for reducing current mismatch;
[0022] FIG. 4 shows a circuit diagram of a charge pump circuit with a replica charge pump; and
[0023] FIG. 5 shows up and down current supply circuits connected to the charge pump circuit of FIG. 4 .
[0024] FIG. 6 shows simulation results of the disclosed charge pump circuit.
DETAILED DESCRIPTION
[0025] Referring to FIG. 4 , a charge pump circuit for reducing current mismatch is disclosed. The charge pump comprises three portions, namely a current source portion 400 , a core charge pump portion 402 and the replica charge pump portion 404 .
[0026] The current source portion 400 comprises an original current source I_bias and three transistors (Q 1 , Q 2 , Q 3 ). These transistors mirror the current from the original current source I_bias to give positive and negative output currents. In particular, the original current I_bias connects to the source of Q 3 and drain of Q 1 . The drain of Q 1 and gates of Q 1 and Q 2 are joined together. The sources of Q 1 and Q 2 are connected to ground. The gate of Q 3 is connected to its drain and further to the drain of Q 2 . The source of Q 3 as well as the original current source I_bias are connected to a positive supply voltage V_dd.
[0027] The core charge pump circuit 402 is connected to the mirrored current sources for receiving up and down currents. At the up current side of M 1 , the source of M 1 is connected to the source of Q 3 and the gates of M 1 and Q 3 are jointly connected to the drain of Q 2 . At the down current side, the source of M 2 connects the sources of Q 1 and Q 2 to ground. The gates of M 2 , Q 2 and Q 1 are connected together to the original current source I_bias directly.
[0028] Between the up and down current carrying transistors M 1 and M 2 , there are two parallel branches comprising four trans-gate switches, namely S 1 , S 2 , S 3 and S 4 . S 1 and S 2 are serially connected between M 1 and M 2 to form a current branch 406 and the charge pump output V_ds (CP_out) is taken between the trans-gate switches S 1 and S 2 . Parallel to S 1 and S 2 , S 3 and S 4 are serially connected to form a dummy branch 408 between M 1 and M 2 where the voltage reference V_ref is taken between the switches S 3 and S 4 . The reference voltage V_ref is also at the output of an Operational Amplifier (OPAMP) Op 1 and control signals D and U for the trans-gate switches (S 1 , S 2 , S 3 and S 4 ) are taken from a Phase Frequency Detector (PFD).
[0029] Between the current branch 406 and the dummy branch 408 , a negative feedback loop 410 (voltage follower) is formed by Opt between the charge pump output 411 and the reference voltage V_ref.
[0030] The replica charge pump circuit 404 is used for sensing the current mismatch of the core charge pump 402 . Within the replica charge pump in out 404 , a feedback loop 412 is used to convert the sensed current mismatch into a voltage signal, V_ctrl.
[0031] The replica charge pump circuit 404 has two transistors (M 3 and M 4 ) and two trans-gate switches (S 5 and S 6 ). M 3 and M 4 have the same size as M 1 and M 2 while S 5 and S 6 have the same size as S 1 to S 4 . M 3 , S 5 , S 6 and M 4 are connected in series. The current mismatch due to the size mismatch and the drain voltages of transistors M 1 and M 2 can be compensated in the implementation shown in FIG. 4 . It will be appreciated by a person skilled in the art that for M 1 and M 3 , and for M 2 and M 4 , a good match can be achieved, typically less than 1% in real circuits. The trans-gate switches S 5 and S 6 are maintained at an on state continuously during the charge pump's circuit 401 operation. Between the trans-gate switches S 5 and S 6 , a connection marked as point A is coupled to a second Operational Amplifier Op 2 to form the negative feedback loop 412 .
[0032] The feedback loop 412 of the replica charge pump circuit 404 is formed around the Operational Amplifier Op 2 . Here, Op 2 is a rail-to-rail OPAMP and it is used as trans-impedance amplifier (TIA). In particular, the input from point A is linked to the inverting input 414 and a control voltage V_ctrl is fed back from the output 416 of Op 2 to the inverting input 414 via a resistor R. On the other hand, the reference voltage V_ref is supplied to the non-inverting input 418 of Op 2 .
[0033] For the “external” connections of the replica charge pump circuit 404 , the source and gate of M 3 are connected to the source and gate of M 1 respectively. Similarly, the source and gate of M 4 are connected to the source and gate of M 2 respectively.
[0034] During operation, the current mismatch of the original charge pump output V_ds (at CP_out) is mirrored to point A by the replica charge pump circuit 404 and supplied to the second Operational Amplifier Op 2 , which is used as TIA. If the “up” current on M 1 is lower than the “down” current, V_ctrl becomes higher than V_ref. If the “up” current is higher than the “down” current, V_ctrl becomes lower than V_ref. Thus, the mismatch in the “up” and “down” current is effectively converted into a differential voltage signal V_ctrl. Additional differential circuits are used to convert the V_ctrl into compensating current signals. The differential circuits are described below with reference to FIGS. 5( a ) and ( b ).
[0035] The disclosed charge pump circuit of FIG. 4 has four additional current input connecting, labeled as I_ 1 , I_ 2 , I_ 3 and I_ 4 . I_ 1 and I_ 3 are for receiving compensation “up” current while I_ 2 and I_ 4 are for receiving compensation “down” current. The compensating “up” current supply circuit is shown in FIG. 5( a ) and the compensating “down” current supply is illustrated by FIG. 5( b ).
[0036] Referring to FIG. 5( a ), the compensating “up” current source 500 is regulated by V_ref and V_ctrl. In particular, there are seven transistors (Q 4 to Q 7 and M 5 to M 7 ) forming the current source. Q 4 to Q 7 form source loop 501 and M 5 to M 7 are connected in parallel. Within the loop, Q 6 's drain connects to Q 4 's drain and Q 7 's drain connects to Q 5 's drain. The sources of Q 4 and Q 5 are connected together to ground via a current source 502 . The sources of Q 6 and Q 7 are connected to a positive voltage V_dd. The gates of Q 6 and Q 7 are also connected to the drain of Q 4 . V_ref is applied to the gate of Q 4 and V_ctrl is applied to the gate of Q 5 . For M 5 to M 7 , all sources are connected to the sources of Q 6 and Q 7 and all gates are connected to the drain of Q 5 . The gate of M 5 is also connected to the drain of Q 5 . The “up” current output to node I_ 1 and I_ 3 are taken from the drains of M 6 and M 7 respectively.
[0037] Referring to FIG. 5( b ), the compensating “down” current is also regulated by V_ref and V_ctrl. In particular, there are seven transistors (Q 8 to Q 11 and M 8 to M 10 ) forming the current source 511 . Q 8 to Q 11 form a loop source 510 and M 8 to M 10 are connected in parallel. Within the loop 510 , Q 10 's drain connects to Q 8 's drain and Q 11 's drain connects to Q 9 's drain. The sources of Q 8 and Q 9 are connected to ground. The sources of Q 10 and Q 11 are connected to a positive voltage V_dd via a current source 512 . The gates of Q 8 and Q 9 are connected to the drain of Q 10 . V_ref is applied to the gate of Q 10 and V_ctrl is applied to the gate of Q 11 . For M 8 to M 10 , the sources are connected to the sources of Q 8 and Q 9 at ground and all gates are connected to the drain of Q 9 . The gate of M 8 is also connected to the drain of Q 9 . The compensating “down” current output I_ 2 and I_ 4 are taken from the drains of M 8 and M 9 respectively. It will be appreciated that sources 502 and 512 may be mirrored from one current source.
[0038] The above-disclosed charge pump circuits provide current mismatch feedback. The feedback will compensate the current mismatch and force “up” and “down” currents closer over a wider V_ds range.
[0039] A simulation result of the disclosed charge pump circuit is presented in FIG. 6 . The vertical axis and horizontal axis denotes the mismatch current value in μA and reference voltage value V_ref respectively. In the graph, the “up” current I_up (curve 600 ) and down current I_down (curve 602 ) are plotted together with the curve 604 of current mismatch. The graph shows that the current mismatch is less than about 1% when the reference voltage V_ref varies from about 0.2V to about 1.5V, i.e. providing a V_ref range of more than about 1V. Also shown in FIG. 6 are the compensating “up” and “down” currents in curves 606 and 608 respectively.
[0040] It will be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive.
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A charge pump circuit and a method of compensating current mismatch in a charge pump circuit. The charge pump circuit comprises a core charge pump circuit; a replica charge pump circuit for sensing a current mismatch in the core charge pump circuit and for converting the sensed current mismatch into a voltage signal V_ctrl; wherein V-ctrl is utilized for compensating the current mismatch in the core charge pump circuit.
| 7
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[0001] The present invention relates to bindings for mounting on snowboards, the design of which makes them particularly ergonomic.
[0002] There are a number of types of snowboard binding, each type being more specifically suited to a particular style.
[0003] Therefore, with reference to so-called “artistic” snowboarding, more commonly known as “freestyle”, use is made of relatively soft boots that allow the user great freedom of movement, permitting great variations in the angle of the tibia relative to the foot. Such qualities are particularly appreciated for snowboarding on semicylindrical trails, which are more commonly known as “half pipes”.
[0004] By virtue of the flexibility of his boots, the snowboarder is able to adopt positions that are particularly inclined relative to the board. The relative flexibility of the boots also allows good perception of the sensations coming from the board. The use or such soft boots requires, however, the use of bindings that have a certain stiffness, particularly in order to withstand rearward bearing forces.
[0005] As regards so-called “downhill” snowboarding, requirements in terms of the precision of curves are all the more important, and therefore the bindings must have an even more accentuated stiffness.
[0006] Therefore, such bindings have a baseplate for mounting on the board and a highback for receiving the rear of the user's boot upper and the bearing forces of the rear of the leg. Such a highback may extend as far as halfway up the calf. The set of straps makes it possible to hold and to grip the boot inside the binding. Such straps generally pass over the front of the foot and at the instep and connect the two sides of the baseplate. More precisely, each strap generally consists at least one strap part that is fixed on the side of the baseplate. This strap part is able to interact either with a complementary strap part located on the other side of the baseplate or even with a fastening mechanism associated with the other side of the baseplate.
[0007] In order to adjust the longitudinal position of the strap part or parts on the boot, reasonably high over the instep or more or less to the front of the front end of the boot, an intermediate part is mounted on the baseplate and has the ability to pivot on an axis that is substantially transverse relative to the baseplate or relative to the lateral side of the boot. The strap part or parts are secured to this intermediate part.
PRIOR ART
[0008] Conventionally, such strap parts consist of a flexible material. In fact, such strap parts must be able to be offset on both sides of the binding in order to allow the user to insert his boot into the binding and then to close the straps over one another. In fact, the straps must be relatively flexible in order to be able to be offset easily, so as to clear the central space of the baseplate for insertion of the boot. The materials of the molded plastics type and foams may be used.
[0009] However, too great a flexibility of the strap parts may make them fragile.
[0010] Owing to the relative flexibility of the strap parts, they tend to fold down unexpectedly or to become wedged under the sole of the boot or even to become wedged between the highback and the boot when the binding is subjected to transverse movements, for example when the user steps into the binding or when the snowboard is being carried.
[0011] This tendency is further increased owing to the fact that the strap parts are generally equipped with a pad in the terminal portion, the purpose of this pad being to distribute and attenuate the pressure exerted by the strap on the user's foot. The presence of this relatively large mass at the end of the strap parts very easily gives rise to the flexible undulation of the latter. Moreover, the fastening mechanism and its component parts also have a mass that causes the strap parts to move in all directions.
[0012] Document DE-44.16.024 discloses a snowboard binding with strap parts that are articulated relative to a baseplate. The strap parts extend in the region of the articulation via rigid branches that are secured and at right angles relative to the strap parts, and lying in the inner space of the bindings. These branches are capable of receiving the bearing forces of the foot when the user steps into the binding. The strap parts are thus automatically positioned above the boot such that the user has only to carry out the operations of positioning the fastening means.
[0013] This solution has proved to be complex and totally unsuitable for bindings with strap parts that have the ability to pivot on an axis transverse relative to the baseplate. This solution also requires major modifications to the baseplate and to the straps as compared to a conventional, existing snowboard binding.
SUMMARY OF THE INVENTION
[0014] A first problem that the invention proposes to solve is that of imparting stiffness to all the elements of the binding, given that these elements have a point of articulation. A second problem that is posed is that of designing a binding that allows the user to step into it easily. A third problem is that of eliminating the inconvenience caused to the user owing to the fact that the strap parts are able to move inopportunely in a number of ways.
[0015] A snowboard binding includes a baseplate and at least one strap formed of strap parts that are each articulated relative to a side of the baseplate and that interact with one another in order to ensure gripping of the strap over a boot.
[0016] According to a first aspect of the invention, the snowboard binding is defined in that the strap parts are formed of curved rigid parts. The ends of the curved rigid parts come opposite one another. One of the strap parts is equipped with an articulated lever allowing the displacement of a hooked zone. This hooked zone is capable of interacting with a notched zone produced on the upper face of the opposite strap part.
[0017] “Rigid parts” are understood to mean parts that are unable to deform under their own weight. In other words, owing to their stiffness, the end of the strap parts that equip the bindings according to the invention has only a circular path relative to the point of attachment to the baseplate. This also means that the strap part can no longer impede the user's operations. Even when the open binding undergoes large-amplitude movements, the strap parts retain their geometry and may be used immediately by the user without the latter having to reset them.
[0018] When the strap parts are in the closed position, placed over the binding of the boot, and even when they are unfastened, they do not fall back unexpectedly on either side of the boot without the user carrying out the appropriate operation.
[0019] Preferably, the length of the link between the articulated lever and the hooked zone may be adjustable. Thus, these two strap parts may, for example, lay on the snowboard boot when the latter is positioned in the binding such that fastening takes place substantially in the central region of the boot.
[0020] In order to provide both stiffness and comfort for the user, at least one of the strap parts may be equipped on its lower face with a pad for coming into contact with the boot. The pad may, for example be arranged under the strap part that includes the notched zone.
[0021] The curved rigid parts of the strap parts each favorably comprise a hinge allowing the strap part to pivot in order to open and close the binding. The articulation of the strap parts is either directly on the baseplate of the binding or in the region of a part that is itself fixed on the bindings. This intermediate part may itself be articulated on the baseplate in order to allow pivoting of the strap relative to an axis that is substantially transverse relative to the lateral side of the boot.
[0022] In a particularly favorable manner, each strap part may have two stable equilibrium positions. These two positions are an open position, in which the strap part is clear of the front of the boot, and a closed position, in which the strap part is folded over the front of the binding in order to interact with the fastening means. The articulation of the strap part relative to the binding is thus arranged such that, between these two positions, and without the user's intervention, the strap part is displaced automatically toward one of the two stable positions.
[0023] Thus, the user has to exert a sufficiently intense force in order to counteract the characteristic articulation and to move the rigid strap parts from one stable position to the other stable position.
[0024] According to a second aspect of the invention, a snowboard is defined in that it comprises a binding as described above.
BRIEF DESCRIPTION OF THE FIGURES
[0025] The invention will be properly understood and its various advantages and different characteristics will become more apparent from the following description of the non-limiting illustrative embodiment, with reference to the appended diagrammatic drawings in which:
[0026] [0026]FIG. 1 shows a rear, perspective view of a snowboard binding according to the invention;
[0027] [0027]FIG. 2 shows a front view of the binding, with a boot, and with the rear binding straps removed; and
[0028] [0028]FIG. 3 shows a perspective view of two of the strap parts for the binding.
DETAILED DESCRIPTION OF THE INVENTION
[0029] A snowboard binding ( 1 ) comprises a baseplate ( 2 ) for mounting on the snowboard (not shown). At the rear of the baseplate ( 2 ) is fixed a heel loop ( 3 ) connecting two rear flanks ( 4 ) of the baseplate ( 2 ), passing behind the heel of the boot ( 6 ).
[0030] This heel loop ( 3 ) receives a highback ( 7 ) for coming into contact with the rear part of the upper of the boot ( 6 ), in order to receive the bearing forces of the rear of the leg. The highback ( 7 ) is mounted pivotably relative to the heel loop ( 3 ) by means of two pivot pins ( 8 ). By virtue of this arrangement, it is possible to fold down the highback ( 7 ) when the binding ( 1 ) is no longer in use and thus to limit its overall bulk and facilitate its storage.
[0031] Traditionally, such a binding ( 1 ) comprises retention means that hold the boot ( 6 ) of the user in the binding ( 1 ). These retention means take the form of two gripping straps ( 9 and 11 ). The first of these gripping straps ( 9 ), known as the front strap, is generally arranged in the region of the front end of the binding ( 1 ) so as to lie on the zone ( 12 ) at the front of the boot ( 6 ) in the region of the toes. The second of these gripping straps ( 11 ), known as the rear strap, is generally arranged in the region of the instep ( 13 ) of the boot ( 6 ).
[0032] The front strap ( 9 ) is fixed on two front flanks ( 14 ) of the baseplate ( 2 ). The front strap ( 9 ) is mounted pivotably relative to these front flanks ( 14 ) by means of two pivot pins ( 16 ). In order to obtain the above, two front intermediate parts ( 17 ) are pivotably secured, for example by means of screwing, to the inside of the front flanks ( 14 ) in the inner zone of the binding ( 1 ). It will be noted that the front strap ( 9 ) may also be mounted directly on the front flanks ( 14 ), but it will then have no ability to move and thus no ability to be adjusted forward or rearward.
[0033] A right front strap part ( 18 ) and a left front strap part ( 19 ) form the front strap ( 9 ). The right front strap part ( 18 ) and the left front strap part ( 19 ) come opposite one another and interact together. Front fastening means ( 21 ) provided on these two right ( 18 ) and left ( 19 ) front strap parts allow the precise positioning of the right front-strap part ( 18 ) relative to the left front strap part ( 19 ), and thus the gripping of the boot ( 6 ).
[0034] The rear strap ( 11 ) is fixed on the heel loop ( 3 ) of the baseplate ( 2 ). The rear strap ( 11 ) is mounted pivotably relative to this heel loop ( 3 ) by means of two pivot pins ( 8 ) already provided for the rocking of the highback ( 7 ). To obtain the above, two rear intermediate parts ( 22 ) are pivotable and secured, for example by means of screwing, to the outside of the heel loop ( 3 ) in the outer zone of the binding ( 1 ). It will be noted that the rear strap ( 11 ) may also be mounted directly on the heel loop ( 3 ) but that it will then have no ability to move and thus no ability to be adjusted forward and rearward.
[0035] A right rear strap part ( 23 ) and a left rear strap part ( 24 ) form the rear strap ( 11 ). The right rear strap part ( 23 ) and the left rear strap part ( 24 ) come opposite one another and interact together. Rear fastening means ( 26 ) provided on the two right ( 23 ) and left ( 24 ) rear strap parts allow the precise positioning of the right rear strap pat ( 23 ) relative to the left rear strap part ( 24 ) and thus the gripping of the boot ( 6 ).
[0036] In order to allow the operations of opening and closing the front ( 9 ) and rear ( 11 ) straps, the pivot movements of the strap parts ( 18 , 19 , 23 and 24 ) relative to the baseplate ( 2 ) are obtained by means of an articulation forming a hinge ( 27 ). At one of their ends, opposite the fastening means ( 21 , 26 ), the curved rigid parts of the right front strap part ( 18 ), of the left front strap part ( 19 ), of the right rear strap part ( 23 ) and of the left rear strap part ( 24 ) each comprise a protrusion ( 28 ). This protrusion ( 28 ) is centered, slightly swollen and hollow, it being possible for a pin ( 29 ) to pass inside the hollow. In a complementary manner, the two front intermediate parts ( 17 ) and the two rear intermediate parts ( 22 ) comprise a double boss that surrounds the protrusion ( 28 ). This double boss is slightly swollen and hollow, it being possible for the pin ( 29 ) to pass inside the double hollows.
[0037] The pin ( 29 ) secures together the strap parts ( 18 , 19 , 23 and 24 ) and the corresponding intermediate parts ( 17 , 22 ). To allow a movement for opening and closing the strap parts ( 18 , 19 , 23 and 24 ), the pin ( 29 ) is thus substantially parallel to the front flanks ( 14 ) of the baseplate ( 2 ) or to the tangent to the heel loop ( 3 ) in the region of the pivot pin ( 8 ). The articulation that forms the hinge ( 27 ) may also be bistable, for example with a swollen zone engaging with a flexible blade.
[0038] The front fastening means ( 21 ) are substantially identical to the rear fastening means ( 26 ). These front ( 21 ) and rear ( 26 ) fastening *means comprise an articulated lever ( 31 ) at the free end of the left front strap part ( 19 ) and of the left rear strap part ( 24 ). This articulated lever ( 31 ) pivots and allows the displacement of a zone ending in a hook ( 32 ). This hook ( 32 ) engages in a notched zone ( 33 ) made on the upper face at the free end of the opposite strap part, i.e. of the right front strap part ( 18 ) and of the right rear strap part ( 23 ), respectively.
[0039] In order to allow extremely precise gripping of the boot ( 6 ), the length of the link between the articulated lever ( 31 ) and the hooked zone ( 32 ) is adjustable. For this purpose, a threaded rod ( 34 ), that can be actuated by a screwdriver, turns in a corresponding tapped housing ( 36 ).
[0040] According to the invention, the right front strap part ( 18 ) and the left front strap part ( 19 ) are each formed by a curved rigid part. According to the invention, the right rear strap part ( 23 ) and the left rear strap part ( 24 ) are each formed by a curved rigid part.
[0041] The materials used for all the curved strap parts ( 18 , 19 , 23 , 24 ) have a stiffness that is close, for example, to that of shaped aluminum. The curved rigid parts are thus made from non-deformable rigid molded polymer materials, or even from aluminum. The curved rigid parts may be covered with a supplementary coating, of the foam, fabric, etc. type.
[0042] The radius of curvature of the right front strap part ( 18 ) and of the left front strap part ( 19 ) corresponds substantially to the curvature of the zone at the front ( 12 ) of the boot ( 6 ). The radius of curvature of the right rear strap part ( 23 ) and of the left rear strap part ( 24 ) corresponds substantially to the curvature of the instep ( 13 ) of the boot ( 6 ).
[0043] In order to improve the comfort of the straps ( 9 and 11 ) of the binding ( 1 ), the right front ( 18 ) and right rear ( 23 ) strap parts each comprise a pad ( 37 ). The pad ( 37 ) is positioned on the lower face that comes into contact with the boot ( 6 ). The pad is arranged under the notched zone ( 33 ).
[0044] The present invention is not limited to the embodiments described and illustrated. A number of modifications may be made without thereby departing from the context defined by the scope of the set of claims.
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A binding for a snowboard includes a baseplate and at least one strap formed of strap parts that are each articulated relative to a side of the baseplate and that interact with one another in order to ensure the gripping of the strap over a boot.
The strap parts are formed by curved rigid parts, the ends of which come opposite one another, and one of the strap parts is equipped with an articulated lever allowing the displacement of a hooked zone capable of interacting with a notched zone made on the upper face of the opposite strap part.
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BACKGROUND OF THE INVENTION
This invention relates to an incinerator for the evaporative separation of sludge into water vapor and dry solids.
Sludge incinerators heretofore have been provided to obtain this separation. The prior art incinerators, however, have been able to process only a relatively low volume of sludge. Further, they have required large centrifuges to affect complete separation of the water, particularly with high solid sludges. Moreover, the fuel to sludge ratio of the prior sludge incinerators has been quite high, resulting in costly operation thereof.
SUMMARY OF THE INVENTION
In its basic concept, the sludge incinerator of this invention provides a primary chamber and associated longitudinally spaced alternate sludge inlet tubes and primary burners to flash evaporate water from high moisture sludges, and to separate combustible and non-combustible components. An afterburner also may be provided to insure substantially complete oxidation of the resulting products of combustion essentially to pure water and carbon dioxide.
It is by virtue of the foregoing basic concept that the principal objective of this invention is achieved; namely, to overcome the aforementioned disadvantages and limitations of prior sludge incinerators.
Another object of this invention is to provide a sludge incinerator of the class described wherein the sludge is reduced substantially to dry solids, pure water and carbon dioxide.
Still another object of this invention is to provide a sludge incinerator of the class described which may be automatically controlled for continuous operation.
A further object of this invention is to provide a sludge incinerator of the class described which is of simplified construction for economical manufacture and is of rugged design permitting long, continuous use with minimum maintenance and repair.
The foregoing and other objects and advantages of this invention will appear from the following detailed description taken in conjunction with the accompanying drawings of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a sludge incinerator embodying the features of this invention.
FIG. 2 is a foreshortened elevation view as viewed from the bottom FIG. 1, portions being broken away to disclose details of internal construction.
FIG. 3 is a sectional view taken along the line 3--3 in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, the sludge incinerator includes a primary chamber 10 formed of an elongate, cylindrical tank 12, generally closed at both ends. Since the sludge incinerator operates at sustained high temperatures, the primary chamber is provided with a refractory lining 12'. One end of the primary chamber comprises door 14 pivotally mounted to the cylindrical tank by such means as hinge 16, and sealable in the closed position by such means as a latch (not shown). A view port (not shown) may be included in the door to allow visual access to the primary chamber when the sludge incinerator is in operation.
The primary tank 12 may be supported by any desired form of structural support. In the embodiment illustrated, a post and beam base 18 with side supports 20 is utilized to support it in a substantially horizontal position.
Feed means, such as inlet tubes 22, are included to feed the raw sludge into the primary chamber 10. Preferably, several such tubes are provided and are medially positioned on both sides of the primary chamber substantially along its horizontal center line at longitudinally spaced intervals. The tubes are "Y"-shaped to allow introduction of compressed air from a source (not shown) through branch tube 22', along with the sludge from main tube 22 in order to maximize atomization of the sludge and thereby promote complete combustion. In the preferred embodiment, the sludge is pressurized to expedite its passage into the primary chamber. The pressure of the sludge, however, should be somewhat less than that of the compressed air. Thus, for example, where the sludge is supplied at 50-60 pounds per square inch gauge, the compressed air should be supplied at about 80 pounds per square inch gauge. Check valves (not shown) in the main tubes 22 upstream of the branch tubes 22' prevent the higher pressure air from backing up through the sludge tubes. Conventional high pressure spray nozzles (not shown) are located at the inner ends of the tubes 22 to atomize the sludge-air mixture and inject it into the primary chamber. If desired, waste oil or other flammable hydrocarbons may be introduced along with the sludge to aid in the ignition of the sludge.
Primary burners 24 are mounted in the primary chamber to effectuate flash evaporization of the water contained in the sludge and incineration of the solids content of the sludge. In the embodiment illustrated, six propane fired, full modulating burners are provided, three on each side of the primary chamber located approximately at its horizontal center line at longitudinally spaced intervals, bracketing the pair of sludge inlet tubes 22. Other types of primary burners and sources of combustible gases may be utilized for this purpose, if desired.
To further enhance the efficiency of operation and hence increased production of the incinerator, lengths of mild steel chain 26 may be draped downward from the top of the chamber 10 to opposite sides thereof, as illustrated in FIGS. 2 and 3. Preferably, the lengths of chain of spaced apart longitudinally of the chamber 10, for example about 6 to 12 inches. Thus, they pick up the flame directly from the burners 24 and become red hot. They retain such heat and thereby provide a multiplicity of hot surfaces from which to aid in the flash evaporation of volatile components of the sludge.
In the preferred embodiment illustrated, and best shown in FIG. 3, the sludge inlet tubes are disposed to inject the sludge-air mixture into the chamber at an angle slightly inclining from horizontal, as indicated by the arrows 22a, while the burners inject fuel-air mixture into the chamber at an angle slightly declining from horizontal, as indicated by the arrows 24a. This arrangement has been found to provide substantially maximum mixing of the sludge spray and gases of combustion within the chamber.
Conveyor means is located on the bottom portion of the primary chamber to convey the non-combustible solids out of the primary chamber. For this purpose, air-cooled screw conveyor 28 is rotatably mounted in the primary chamber by bearing 30 at one end and motor 32 at the other end. The dry solids are then passed out of the primary chamber through an air lock, such as rotary valve 34 located below the end of the air-cooled screw conveyor in the bottom of the primary chamber.
Afterburner 36 is mounted to the upper portion of the downstream end of the primary chamber. It includes a secondary chamber 38 formed of an elongate cylindrical tank similar to that used for the primary chamber, however approximately one-half of its diameter. The primary and secondary chambers are interfaced by flame port 40 which comprises a short cylindrical orifice. Due to the high pressure maintained in the primary chamber, the primary combustion products pass through the flame port into the secondary chamber.
Pressurized secondary air is introduced into the afterburner through mixing chamber 42 located about the periphery of the secondary chamber immediately downstream from the flame port. The mixing chamber includes an annular air supply duct 44 which is located outside the secondary chamber and opens therein. Air passageways 46 are located through the secondary chamber wall, communicating the annular air supply duct with the interior of the chamber. They are oriented substantially tangentially to the flame port to induce turbulent mixing of the secondary air with the primary combustion products. A motor-driven axial fan 48 is located in an opening in the lower portion of the annular air supply duct to pressurize the secondary air.
Reignition burners 50 are mounted in the side walls of the secondary chamber adjacent the duct 44 to further oxidize the mixed primary combustion products. They comprise propane fired burners similar to those used for the primary burners. Two such burners are illustrated, one on each side of the secondary chamber approximately at its horizontal center line. Preferably, these burners 50 are arranged to inject flame into the chamber 38 substantially tangentially, to enhance mixing of its gases of combustion with the combustion products of the primary chamber 10.
A vertical stack 52 is located downstream of the afterburner at the end of the secondary chamber 38 opposite primary chamber 10, to transmit the vaporized water and gases of combustion to the atmosphere. Although the stack may serve to create natural draft for this purpose of transporting the products of combustion to the atmosphere, forced draft may be provided if desired or required, as will be understood. Condensation means (not shown) may be positioned in the vertical stack to condense the water for further use, if desired. The afterburner preferably enters the stack tangentially, as illustrated, to effect centrifugal separation of any solids entering the stack.
Since the reduction of the sludge is obtained almost completely by flash evaporation and afterburning, little flushing of the system is required. Thus, if desired, the operation of the sludge incinerator can be automated for continuous operation. Controls and interlocks (not shown) may be included to tie the operation of all of the elements.
In the operation of the sludge incinerator of the present invention, inlet tubes 22 are connected to a supply of raw sludge. Generally, the sludge is stored in a receiving tank (not shown) until fed into the sludge incinerator. The stored sludge is preferably agitated and fed out of the receiving tank through a macerator to uniformly size the sludge materials. A pump may be utilized to pressurize the sludge.
The pressurized sludge in tubes 22 and compressed air in tubes 22' are then injected into the primary chamber as an atomized spray by high pressure spray nozzles located at the inner ends of inlet tubes 22. Since the sludge is injected at the locations bracketed by primary burners 24, it is rapidly heated and oxidized to flash evaporate the water contained therein and oxidize the combustibles content to gaseous phase. The solids gravitate to the bottom of the primary chamber where they are removed by screw conveyor 28.
The resulting water vapor and any unburnt products of combustion pass through flame port 40 and are mixed with pressurized secondary air in mixing chamber 42. The reignition burners then reignite and further oxidize this mixture to provide essentially pure water vapor and completely oxidized gaseous combustion products. The water vapor may be recovered by condensation for re-use, if desired. If the gaseous combustion products include odoriferous compounds, they may be collected in conventional manner.
It will be apparent to those skilled in the art that various changes may be made in the size, shape, type, number and arrangement of parts described hereinbefore. For example, six-1,750,000 BTU propane fired primary burners will process approximately 300 gallons of sludge per hour. Other types or sizes of burners, types of fuel, and burner locations would also suffice, however. Furthermore, although the sludge incinerator illustrated utilizes horizontally mounted primary and secondary chambers, other shapes and orientations may be utilized. The screw conveyor 28 may be omitted if the incinerator is to be used with sludge having little ash, in which case the ash accumulation may be removed periodically by a vacuum head, scraper, or other suitable means. The chains 26 may be arranged in a variety of ways, other than as illustrated. For example, a single row of longitudinally spaced chains may hang freely from hangers located at the top center of the chamber. Alternatively, a plurality of laterally spaced, longitudinal rows may hang freely from laterally spaced hangers. These and other modifications may be made as desired without departing from the spirit of this invention.
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A sludge incinerator for use in the flash evaporation of water contained in high moisture sludges comprises a primary chamber, with longitudinally spaced inlet tubes to introduce the sludge and compressed air therein in an atomized spray, and primary burners intermediate the inlet tubes, to heat and burn the sludge, thus separating it into dry solids and water vapor. A screw conveyor removes the dry solids from the primary chamber. An afterburner, including secondary burners, a secondary air supply, and a mixing chamber to mix the secondary air with the primary combustion products, provides further oxidation to achieve substantially complete combustion of the combustibles content of the sludge and fuel. A vertical stack exhausts these combustibles and vapors from the mixing chamber.
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CROSS REFERENCE TO RELATED APPLICATIONS
This patent application is a continuation-in-part patent application that claims priority to U.S. patent application Ser. No. 14/605,829, entitled “Drill Collar Severing Tool,” filed Jan. 26, 2015, which claims priority to U.S. patent application Ser. No. 14/120,409, entitled “Drill Collar Severing Tool,” filed May 19, 2014, which claims priority to U.S. Provisional Application Ser. No. 61/855,660, entitled “Drill Collar Severing Tool,” filed May 20, 2013, all of which are incorporated herein in their entireties.
STATEMENT REGARDING FEDERAL RESEARCH OR DEVELOPMENT
Not applicable.
FIELD
The present invention relates to the earthboring arts. More particularly, the present invention relates, generally, to methods and devices for severing drill pipe, casing and other massive tubular structures by the remote detonation of an explosive cutting charge.
BACKGROUND
Deep well earthboring for gas, crude petroleum, minerals and even water or steam requires tubes of massive size and wall thickness. Tubular drill strings may be suspended into a borehole that penetrates the earth's crust several miles beneath the drilling platform at the earth's surface. To further complicate matters, the borehole may be turned to a more horizontal course to follow a stratification plane.
The operational circumstances of such industrial enterprise occasionally present a driller with a catastrophe that requires him to sever his pipe string at a point deep within the wellbore. For example, a great length of wellbore sidewall may collapse against a drill string and cause the drill string to wedge tightly in the well bore. Thereafter, the wedged drill string cannot be pulled from the well bore and, in many cases, cannot even be rotated. A typical response for salvaging the borehole investment is to sever the drill string above the obstruction, withdraw the freed drill string above the obstruction, and return to the wellbore with a “fishing” tool to free and remove the wedged portion of the drill string.
The drill string weight, which is bearing on the drill bit and necessary for advancement into the earth strata, is provided by a plurality of specialty pipe joints having atypically thick annular walls. In the industry vernacular, these specialty pipe joints are characterized as “drill collars.” A drill control objective is to support the drill string above the drill collars in tension. Theoretically, only the weight of the drill collars bears compressively on the drill bit. With a downhole drilling motor, which is configured for deviated bore hole drilling, the drill motor, bent sub and drill bit are positioned below the drill collars. This drill string configuration does not rotate in the borehole above the drill bit. Consequently, the drill collar section of the drill string is particularly susceptible to borehole seizures and because of the drill collar wall thickness, is also difficult to cut.
When an operational event, such as a “stuck” drill string, occurs, the driller may use wireline suspended instrumentation that is lowered within the central, drill pipe flow bore to locate and measure the depth position of the obstruction. This information may be used to thereafter position an explosive severing tool within the drill pipe flow bore.
Typically, an explosive drill pipe severing tool comprises a significant quantity, 800 to 1,500 grams (12,345 grains to 23,149 grains) for example, of high order explosive, such as RDX, HMX or HNS. The explosive powder is compacted into high density “pellets” of about 22.7 grams to about 38 grams (350 grains to 586 grains) each. The pellet density is compacted to about 1.6 gm./cm 3 to about 1.65 gm./cm 3 (404.6 grains/inch 3 to 417.3 grains/inch 3 ) to achieve a shock wave velocity greater than about 9144 meters/second (30,000 ft/sec), for example. A shock wave of such magnitude provides a pulse of pressure in the order of 2.8×10 4 MPa (4×10 6 psi). It is the pressure pulse that severs the pipe.
In one form, the pellets are compacted, at a production facility, into a cylindrical shape for serial, juxtaposed loading at the jobsite as a column in a cylindrical barrel of a tool cartridge. Due to weight variations within an acceptable range of tolerance between individual pellets, the axial length of explosive pellets fluctuates within a known tolerance range.
Extreme well depth is often accompanied by extreme hydrostatic pressure. Hence, execution of the drill string severing operation may be required at hydrostatic pressures above 206.94 MPa (30,000 psi). Such high hydrostatic pressures tend to attenuate and suppress the pressure of an explosive pulse to such degree as to prevent separation.
One prior effort, by the industry, to enhance the pipe severing pressure pulse and to overcome high hydrostatic pressure suppression has been to detonate the explosive pellet column at both ends simultaneously. Theoretically, simultaneous detonations at opposite ends of the pellet column will provide a shock front from one end colliding with the shock front from the opposite end within the pellet column at the center of the column length. On collision, the pressure is multiplied, at the point of collision, by about 4 to 5 times the normal pressure cited above. To achieve this result, however, the detonation process, particularly the simultaneous firing of the detonators, must be timed precisely in order to assure collision at the center of the explosive column.
Such precise timing is typically provided by means of mild detonating fuse and special boosters. However, if fuse length is not accurately cut or problems exist in the booster/detonator connections, the collision may not be realized at all and the device will operate as a “non-colliding” tool with substantially reduced severing pressures.
The reliability of state-of-the-art severing tools is further compromised by complex assembly and arming procedures required at the well site. With those designs, laws and regulations require that explosive components (detonator, pellets, etc.) must be shipped separately from the tool body. Complete assembly must then take place at the well site under often unfavorable working conditions.
Finally, the electric detonators utilized by many state-of-the-art severing tools are vulnerable to stray electric currents and uncontrolled radio frequency (RF) energy sources, thereby further complicating the safety procedures that must be observed at the well site.
SUMMARY OF THE INVENTION
The pipe severing tool of the present invention comprises an outer housing of such outside diameter that is compatible with the drill pipe flow bore diameter intended for use. Distinctively, the housing wall is extremely thin (e.g. 0.028 in.) and vented to the surrounding exterior environment for interior/exterior pressure equalization. Accordingly, the only material limitation on the housing is sufficient wall strength to withstand the rigors of well descent.
Another consequence of equalizing the interior housing pressure with the exterior well bore pressure is the design freedom to use a thin wall metallic tube to house the main load explosive charge. Furthermore, for a given external housing diameter, a larger internal diameter is available for explosive loading and, therefore, a greater quantity of explosive per unit length of housing. Synergistically, the shock value of an explosive detonation is exponentially increased by an increased explosive quantity, often by the cube.
Vented housing exposure of the main load explosive to downhole fluids, such as water and petroleum based drilling fluids, is enabled by the use of fluid impermeable binders, such as Teflon or any other suitably hydrophobic polymer, which can be combined with formulations of HMX and other military grade explosives. Explosives of such formulations have been discovered to absorb well fluids at very low rates of deterioration. Little or no explosive energy is lost to well fluid exposures that occur in the order of an hour, which is usually more than an adequate time to accurately position a cutting tool for detonation.
The lower end of the present invention housing tube can be closed by a sliding, overlap assembly with a nose plug. The nose plug can be secured by screw threads to a tubular load rod. The housing tube upper end can be closed by a sliding, overlap assembly with a top carrier plug. However, the tubular load rod is threaded into the inside face of the top carrier plug and extends along the housing tube axis for substantially the full length of the housing tube.
A first bi-directional booster can be secured within the bore of the load rod tube at the top carrier plug. A first mild detonation cord can be housed along the length of the load rod tube bore, from the first booster to a second bi-directional booster at the nose plug end of the load rod tube. A third bi-directional booster can be secured in the top carrier plug for initiating a second mild detonation cord. The length of a second mild detonation cord can be laid in the trough of a helical flute that can be formed on the surface of a timing spool. Opposite ends of the second detonation cord can be disposed within detonation proximity of third and fourth bi-directional boosters. In a first embodiment of the invention, the first and second detonation cords are of identical length. In another embodiment of the invention, the first, second, or both detonation cords may be pre-shrunk.
A pellet of initiating explosive (i.e., booster explosive) can be positioned within a socket in the top carrier plug, between the first and third bi-directional boosters. A thin, fluid impermeable bulkhead can be used to separate the initiating explosive from the first and third bi-directional boosters, to isolate the booster pellet from the downhole well fluid environment of the main lower explosive housing.
The timing spool is a substantially cylindrical body element, which can have an axial bore and a helical surface flute about the cylindrical axis. The timing spool can be secured to the load rod by rod penetration through the axial bore of the spool. An upper axial sleeve extension from the spool body can abut the top carrier plug inside face to secure a spacial separation of the spool from the booster carrier. A lower axial sleeve extension from the spool body can support the fourth bi-directional booster and can serve as a limit stop for a stack of washer-shaped primary explosive pellets, which can be aligned along the length of the load rod. A coil spring can be compressed between an inside face of the nose plug and a terminal pellet in the column of the main load explosive to bias the column tightly against the lower sleeve extension.
Those of skill in the art of oilfield explosives will appreciate a characteristic of the invention that allows the bi-directional boosters and detonation cord to be transported while assembled with the housing tube structure, as a unit, by traditional carriers. The main load explosive material and the explosion initiating booster pellet are removed from the assembly for isolated transport. The housing tube, bi-directional boosters and detonation cord, in operational assembly, are in compliance with standard transport regulations. At the site of use, the main load explosive pellets and initiating booster may be quickly inserted.
The invention assembly and loading sequence includes a separation of the housing tube and nose plug, as a unit, from the booster carrier and load rod. Measured quantities of military grade explosive material, such as HMX, RDX and HNS that can be blended with a fluid impervious binder of polymer material that inhibits fluid penetration of, or absorption by, the explosive material, is pressed into annular disc shaped pellets that can have a central aperture with an inside diameter that can be slightly greater than the load rod diameter. The outside diameter of the pellets corresponds to the inside diameter of the housing tube. A multiplicity of such pellets can be aligned in a column along the length of the load rod, with the first pellet engaging the distal end of the lower axial sleeve of the timing spool and in detonation proximity with the fourth bi-directional booster.
With the predetermined number of main load explosive pellets in place along the load rod length, the housing tube and nose plug are repositioned over the column of the main load pellets. Threading the nose plug onto the load rod compresses a coil spring against the lower-most main load pellet. The thin wall housing tube remains free of axial compression.
An embodiment of the present invention includes an apparatus for severing a length of pipe, which can comprise a tubular housing having an internal bore and a plurality of bi-directional boosters, and one or more vents in the housing to substantially equalize fluid pressure within the bore with fluid pressure outside of the tubular housing. The apparatus can include a first detonation cord that can have a first length between a first bi-directional booster and a second bi-directional booster of said plurality of bi-directional boosters. In addition, the apparatus can comprise a second detonation cord that can have a first length between a third bi-directional booster and a fourth bi-directional booster of said plurality of bi-directional boosters. The embodiment of the apparatus can include a main load explosive material, positioned in the tubular housing and located between the second bi-directional booster and the fourth bi-directional booster of the plurality of bi-directional boosters; a fluid impermeable material that can be mixed with the main load explosive material; and an initiating booster explosive that can be used for simultaneously initiating the first and the third bi-directional boosters of the plurality of-bidirectional boosters.
In an embodiment, the main load explosive material can be pressed into a plurality of annular pellets, and the plurality of annular pellets can be compressed to a pressure corresponding to an expected detonation environment pressure. Corresponding to the expected detonation environment pressure may entail either matching or exceeding the expected detonation environment pressure or, alternatively, if the expected detonation environment pressure is in excess of the pressure required to compress the explosive material to its maximum possible density, simply applying sufficient pressure to achieve said maximum possible density.
In an embodiment of the apparatus, the tubular housing can further comprise a tubular loading rod that can be used for penetrating a central aperture of the plurality of annular pellets. The annular pellets can be aligned along the tubular loading rod, between the second and the fourth of the plurality of bi-directional boosters. In an embodiment, the fourth of the plurality of bi-directional boosters can be disposed within detonation proximity of the main load explosive material.
In an embodiment of the apparatus for severing a length of pipe, the tubular loading rod can comprise a central bore, and the first bi-directional booster and the second bi-directional booster of the plurality of bi-directional boosters can be disposed within the central bore, at respectively opposite ends of the first detonation cord. In an embodiment, a first resilient bias can be positioned within said tubular loading rod, between a second end plug and the second of the plurality of bi-directional boosters, and the first resilient bias can bias the first bi-directional booster and the second bi-directional booster and the first detonation cord toward the pellet of initiating booster explosive.
In an embodiment, the third bi-directional booster and the fourth bi-directional booster of the plurality of bi-directional boosters can be disposed at respectively opposite ends of the second detonation cord. An intermediate portion of the second detonation cord can be located between the third and the fourth of the plurality of bi-directional boosters, wherein the intermediate portion is wound about a timing spool. In an embodiment, the timing spool can comprise a cylindrical body and a helical flute formed on the surface of the body, about an axis thereof.
In an embodiment of the present invention, the apparatus can further comprise a first end plug and a second end plug for enclosing an internal bore between opposite ends of the tubular housing. The first end plug can comprise an initiating booster cavity, wherein the initiating booster cavity can hold the initiating booster explosive. The apparatus can further comprise a firing head that can be secured to the first end plug, and the firing head can comprise a detonator that can be disposed within detonation proximity of the initiating booster explosive. In an embodiment, a second resilient bias can be positioned between the second end plug and the plurality of annular pellets.
In an embodiment, the tubular loading rod can comprise a structural wall surrounding or about the central bore, wherein the structural wall can be penetrated by an aperture, for example, between the second bi-directional booster and a portion of the plurality of annular pellets.
An embodiment of the present invention includes a method of severing a pipe, which comprises the steps of enclosing opposite ends of a tubular housing, venting the tubular housing to substantially equalize fluid pressure within the tubular housing to the fluid pressure outside of the tubular housing, and placing a first bi-directional booster, a second bi-directional booster, a third bi-directional booster, and a fourth bi-directional booster within the tubular housing. The steps of the method can continue by connecting a first detonation cord with a first length between the first bi-directional booster and the second bi-directional booster. In this embodiment, the method can include connecting a second detonation cord with a first length between the third bi-directional booster and the fourth bi-directional booster. The steps of the method can further continue by combining a main load explosive material and a fluid impermeable material into a mixture, and loading the mixture into the tubular housing, between the second and fourth bi-directional boosters. The method steps can conclude by positioning the tubular housing and the mixture inside of a pipe, and simultaneously initiating the ignition of the second and the fourth bi-directional boosters.
In an embodiment, the steps of the method can include the step of pressing the mixture into a plurality of annular pellets, wherein the step of pressing the mixture further comprises compressing the plurality of annular pellets to a pressure corresponding to an expected detonation environment. In an embodiment, the step of loading the mixture into the tubular housing can further comprise aligning the plurality of annular pellets in a column between the second bi-directional booster and the fourth bi-directional booster of the plurality of bi-directional boosters.
In an embodiment, the method can further include the step of penetrating a central aperture of the plurality of annular pellets with a tubular loading rod, wherein the step of placing the first bi-directional booster, the second bi-directional booster, the third bi-directional booster, and the fourth bi-directional booster, of the plurality of bi-directional boosters, can further include placing the first bi-directional booster of the plurality of bi-directional boosters within one end of a central bore of the tubular loading rod and placing the second bi-directional booster of the plurality of bi-directional boosters within the central bore at an opposite end of the tubular loading rod.
The method steps of placing the first, the second, the third, and the fourth of the plurality of bi-directional boosters can further include placing the first bi-directional booster of the plurality of bi-directional boosters within detonation proximity of an initiating booster explosive, and in the same or another embodiment, placing the third bi-directional booster of the plurality of bi-directional boosters within detonation proximity of said initiating booster explosive.
In an embodiment, the step of connecting a second detonation cord can include wrapping the second detonation cord about a timing spool, and positioning opposite ends of the second detonation cord in detonation proximity of the third bi-directional booster and the fourth bi-directional booster, of the plurality of bi-directional boosters.
Other embodiments of the present invention can include an apparatus for severing a length of pipe, wherein the apparatus can comprise a tubular housing that includes an internal bore and at least one vent, wherein the at least one vent can be usable for equalizing fluid pressure within the internal bore to fluid pressure outside of the tubular housing; and a first end cap, positioned on a first distal end of the tubular housing, that is usable to close a first distal end of the internal bore, with an initiating booster explosive located in the first end cap. The apparatus can further comprise a second end cap positioned on a second distal end of the tubular housing and usable to close a second distal end of the internal bore. In addition, the apparatus can include a loading tube positioned within the tubular housing and connecting the first end cap with the second end cap, wherein the loading tube comprises a central bore and extends through a timing spool, and wherein a first bi-directional booster is positioned within the central bore of the loading tube, proximate to the first end cap and in detonation proximity to the initiating booster explosive. In this embodiment of the apparatus, a second bi-directional booster can be positioned within the central bore of the loading tube and proximate to the second end cap, and a first detonation cord can be positioned within the loading tube, between the first and the second bi-directional boosters. In this embodiment, a second detonation cord can have a first length between the third bi-directional booster and the initiating explosive booster, and a main load explosive material can be positioned within the tubular housing, between the second end cap and the third bi-directional booster, for ignition and use in severing the length of a pipe or other tubular. In an embodiment, the main load explosive can be pressed into a plurality of annular pellets, and the loading tube can extend through the plurality of annular pellets. The annular pellets can be aligned along the loading tube, between the second bi-directional booster and the third bi-directional booster.
In an embodiment, the apparatus can include a second detonation cord that is helically wound about the timing spool body. The second detonation cord can extend from the bi-directional booster, through the timing spool, to connect to the initiating booster explosive through an aperture in the first end cap.
An alternative embodiment of the present invention eliminates the use of the timing spool and a second detonation cord. Progression of a detonation front along the column of the main load explosive pellets may be retarded by a select number of timing discs that can be fabricated from a low impedance material, such as Teflon or other suitable polymer, that can be positioned along the load rod, between the adjacent main load explosive pellets. Similar results can be obtained by blending the formulation of the main load explosive with micro bubbles, which can reduce the detonation front velocity.
Such an alternate embodiment can include an apparatus for severing a length of pipe that includes a tubular housing that includes an internal bore and at least one vent, wherein the at least one vent can be usable for equalizing fluid pressure within the internal bore to fluid pressure outside of the tubular housing; and a first end cap, positioned on a first distal end of the tubular housing, that is usable to close a first distal end of the internal bore, with an initiating booster explosive located in the first end cap. The apparatus can further comprise a second end cap positioned on a second distal end of the tubular housing and usable to close a second distal end of the internal bore. In addition, the apparatus can include a loading tube positioned within the tubular housing, between the first end cap and the second end cap. The loading tube can include a first bi-directional booster positioned within the loading tube and in detonation proximity to the initiating booster explosive, a second bi-directional booster positioned within the loading tube and proximate to the second end cap, and a detonation cord positioned within the loading tube and between the first bi-directional booster and the second bi-directional booster. The detonation cord can provide a detonation ignition time interval between ignition of the first bi-directional booster and ignition of the second bi-directional booster. A third bi-directional booster can be located within the first end cap and in detonation proximity to the initiating booster explosive. In this embodiment, a blend of explosive material and fluid impermeable material can be compressed into a plurality of annular explosive pellets, and a first column of the plurality of annular explosive pellets can comprise a first quantity of explosive material aligned along the loading tube, from the second bi-directional booster toward a detonation wave collision point. A second column of the plurality of annular explosive pellets can comprise the first quantity of explosive material aligned along the loading tube, from a third bi-directional booster toward the detonation wave collision point, and a detonation wave retarding material that can be usable for retarding the progress of a detonation wave along the second column by a time interval corresponding to a detonation wave time interval along the first column.
In an embodiment, the apparatus can include a fluid barrier positioned in the first end cap, between the tubular housing and the initiating booster explosive, to isolate the initiating booster explosive from fluid within the housing. The detonation wave retarding material can comprise one or more annular discs of polymer material that can be distributed among the plurality of annular explosive pellets, wherein the polymer material can be Teflon. In an embodiment, the detonation wave retarding material can comprise glass micro-balloons that can be blended with the explosive material and the fluid impermeable material.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and further features of the invention will be readily appreciated by those of ordinary skill in the art as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference characters designate like or similar elements throughout.
FIG. 1 is a sectional view of the present invention as assembled for operation.
FIG. 2 is a lower end view of FIG. 1 .
FIG. 3 is a sectional view of the second embodiment of the invention.
FIG. 4 is a sectional view of the third embodiment of the invention.
FIG. 5 is a sectional view of the fourth embodiment of the invention.
FIG. 6 is a sectional view of a fifth embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before explaining selected embodiments of the present invention in detail, it is to be understood that the present invention is not limited to the particular embodiments described herein and that the present invention can be practiced or carried out in various ways. As used herein, the terms “up” and “down”, “upper” and “lower”, “upwardly” and downwardly”, “upstream” and “downstream”; “above” and “below”; and other like terms, indicating relative positions above or below a given point or element, are used in this description to more clearly describe some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate. Moreover, in the specification and appended claims, the terms “pipe”, “tube”, “tubular”, “casing”, “liner” and/or “other tubular goods” are to be interpreted and defined generically to mean any and all of such elements without limitation of industry usage.
Embodiments of the present invention relate, generally, to methods and devices for severing drill pipe, casing and other massive tubular structures by the remote detonation of an explosive cutting charge. Referring to the FIG. 1 , a cross-sectional view of the present invention is shown that includes a tubular outer housing 10 , which is secured at an upper distal end to a top carrier plug 12 . The outer housing 10 has an internal bore 11 that is closed at its lower end by a nose plug 14 (also shown in FIG. 2 ). Notably, the housing 10 interior is vented to the exterior by the use of tubular wall apertures 16 .
The upper end of the housing bore 11 is closed by a firing assembly, which can comprise a top carrier plug 12 and a firing head 26 , as shown. An internal cavity 20 in the top carrier plug 12 is formed to receive a pellet of initiating booster explosive 22 . Thin, fluid pressure bulkheads 24 are shown, for example as fluid barriers, that can be positioned across the initiating booster cavity bottom to isolate the initiating booster explosive 22 from the well fluid and pressure environment that can occupy the interior bore of the housing 10 due to the apertures 16 (i.e., vents).
The upper end of the top carrier plug 12 can include an internally threaded socket 18 , as shown in FIG. 1 . The socket 18 can receive the firing head 26 that positions a detonator 28 in detonation proximity of the initiating booster explosive 22 . Detonation proximity is that distance between a particular detonator and a particular receptor explosive within which ignition of the detonator will initiate a detonation of the receptor explosive.
The loading rod 30 can be secured to the top carrier plug 12 by threads, and the loading rod 30 can project from the inside face 32 of the plug 12 , along the housing 10 axis. The opposite distal end of the loading rod 30 can be threaded into a socket 15 in the nose plug 14 .
The upper end of the loading rod 30 can penetrate an axial bore through and along the length of a generally cylindrical timing spool body 34 . The cylindrical surface of the timing spool body 34 can be formed with a helically wound flute 36 . Opposite ends of the timing spool body 34 can be formed as reduced outside diameter sleeves 38 and 39 . The upper sleeve 38 can be usable for spacing the spool body 34 from the top carrier plug 12 . The lower sleeve 39 can be usable for spacing the spool body 34 from the uppermost main load explosive pellet 40 and can provide structural support for a bi-directional booster 48 . Bi-directional boosters 42 , 44 , 46 , 48 may additionally be self-supporting through compression prior to loading within housing 10 or loading rod 30 .
As shown in FIG. 1 , the length of a first detonation cord 43 is housed within the central bore of the loading rod 30 and links the first bi-directional booster 42 with the second bi-directional booster 44 . The first bi-directional booster 42 is housed within the upper end of the bore of the loading rod 30 and within detonation proximity of the initiating booster explosive 22 . The second bi-directional booster 44 is housed near the lower distal end of the bore of the loading rod 30 and against the resilient bias of a coil spring 50 , also positioned within the bore of the loading rod 30 . The coil spring 50 maintains a compressive contact between the first and second bi-directional boosters and the first detonation cord 43 . A slit is cut into the structural wall of the loading rod 30 , adjacent the second bi-directional booster 44 , to provide an ignition initiation window 52 between the second bi-directional booster 44 and the adjacent main load explosive pellets 40 . A larger coil spring 54 surrounds the lower end of the load rod 30 to apply a resilient bias between the nose plug 14 and the end-most main load explosive pellet 40 .
In the embodiment shown in FIG. 1 , a third bi-directional booster 46 can be secured within an aperture 13 (shown in FIG. 3 ) that penetrates the transverse wall 32 (i.e., inside face wall) of the top carrier plug 12 to position the third bi-directional booster 46 in detonation proximity of the initiating explosive 22 . As further shown in the embodiment of the present invention shown in FIG. 1 , a fourth bi-directional booster 48 can be secured to the lower timing spool sleeve 39 . The third and fourth bi-directional boosters 46 and 48 can be linked by a second mild detonation cord 45 , which has substantially the same length as the first mild detonating cord 43 . However, the intermediate length of the second detonation cord 45 is wound about the flutes 36 on the timing spool 34 surface.
The distal end of the nose plug 14 can be tapered back from a central boss 56 to provide flexure clearance for the two or more centralizers 58 , as shown by FIG. 2 , which are used for centralizing the high energy severing tool within a tubular and/or the wellbore. Each centralizer 58 can be secured by a pair of fasteners, such as machine screws 60 , to provide resistance against rotation of the centralizers about the tool axis.
It should be understood that the tool assembly, as described above, may be safely transported by traditional media with the bi-directional boosters 42 , 44 , 46 , and 48 in place and the detonation cords 43 and 45 positioned between the respective bi-directional boosters. However, in transport, no main load explosive material 40 and/or initiating booster pellets 22 are present within the housing 10 assembly.
Annular pellets of main load explosive material 40 can be formed from explosive material, such as RDX, HNX or HNS, which is mixed with a fluid impermeable material, such as Teflon or other polymer as a binder. Approximately 22.7 gms. to 38 gms. (350 grains to 586 grains) of such explosive material is pressed into an annular disc of an outside diameter that is less than the inside diameter of the housing 10 and a central aperture diameter that is greater than the outside diameter of the loading rod 30 . Preferably, the annulus shaped pellets are compacted to a pressure corresponding to an expected detonation environment pressure.
As previously stated, the apparatus may be safely transported to the well site of use with the bi-directional boosters and the detonation cord in place. The main load pellets 40 and initiation booster explosive pellet 22 are transported separately.
Final assembly of the complete severing tool normally occurs on the drilling rig floor at the well site. The housing tube 10 and nose plug 14 , as an integral unit, are withdrawn from the top carrier 12 and loading rod 30 ,
The required number or plurality of main load pellets 40 can be aligned in a column with the pellet central aperture around the loading rod 30 , and the first pellet abutting the lower spool sleeve 39 . Then, the threaded socket 15 of the nose plug 14 can be screwed onto the lower distal end of the loading rod 30 , thereby compressing the load rod spring 50 against the second bi-directional booster 44 and the outer larger spring 54 against the main load explosive pellet 40 assembly.
With the main load explosive pellets aligned in a column over the loading rod 30 , the housing 10 can be secured to the top carrier plug 12 . Next, the pellet of initiating booster explosive 22 can be inserted into the internal cavity 20 , and the firing head 26 can be screwed into the socket 18 of the top carrier plug 12 to position the detonator 28 within detonation proximity of the pellet of initiating booster explosive 22 .
As assembled, the tool can be secured to the end of a suspension string and lowered into the well bore, along the well pipe flow bore. When positioned at the required location, the initiating booster explosive 22 is detonated to start a pair of parallel ignition sequences that meet at the central collision point.
The second embodiment of the invention, illustrated by FIG. 3 , differs from FIG. 1 mainly by the omission of the third bi-directional booster 46 . As shown in FIG. 3 , the first detonation cord 43 is positioned between the first bi-directional booster 42 and the second bi-directional booster 44 , and the second detonation cord 45 connects the fourth bi-directional booster 48 to the initiating booster explosive 22 . As shown, the upper distal end of the second detonation cord 45 is secured within an aperture 13 , thereby positioning the end of the second detonation cord 45 within detonation proximity of the pellet of initiating booster explosive 22 . The intermediate length of the second detonation cord 45 , between the aperture 13 and the bi-directional booster 48 , is wrapped about the flutes 36 of the timing spool body 34 .
A third embodiment of the invention, as shown by FIG. 4 , omits the use of a timing spool body 34 , a second detonation cord 45 , and a fourth bi-directional booster 48 by inserting timing washers 70 between explosive pellets 40 in the upper portion of the main load explosive column. As shown, this embodiment includes a detonation cord 43 positioned between the first bi-directional booster 42 and the second bi-directional booster 44 , with the third bi-directional booster positioned proximate to the initiating booster explosive 22 .
In this third embodiment of the invention, a first column of main load explosive pellets 40 , collectively comprising a predetermined quantity of explosive material and a fluid impermeable material, is aligned along the loading rod 30 , between the second bi-directional booster 44 and a detonation wave collision point. A second column of main load explosive pellets 40 , also collectively comprising the predetermined quantity of explosive material, is aligned along said loading rod 30 , from detonation proximity with the third bi-directional booster 46 to said detonation wave collision point. However, also progressing along the second column from the third bi-directional booster 46 toward said detonation wave collision point is a number of pellet shaped timing washers 70 that are distributed among the main load explosive pellets 40 . Each timing washer 70 retards the progress of the explosive shock front as it advances along the second explosive column from the third bi-directional booster 46 toward the detonation wave collision point. Suitable fabrication materials for such timing washers include numerous polymers, such as Teflon. The total elapsed time between detonation of the first bi-directional booster 48 and the second bi-directional booster 44 corresponds to the total retardation time that must be incurred by the timing washers 70 . As many of the timing washers 70 are provided in the second main load explosive column as is necessary to substantially match the time interval for a detonation wave to travel along the first detonation cord 43 , from the first bi-directional booster 42 to the second bi-directional booster 44 , so the two primary explosive shock waves, arising from the same quantity of explosive material in both columns, will collide at the detonation wave collision point.
As a variant of FIG. 4 , the embodiment shown in FIG. 5 provides glass micro-bubbles that can be blended with the explosive material of the second column along with the fluid impermeable material. Such micro-bubbles are known to retard the shock wave advance through explosive material. In this example, the micro-bubble blended pellets 41 comprise the second column of main load explosive. As in the second example, however, the same quantity of explosive material is provided for both columns.
As a further variant, the embodiments depicted in FIGS. 4-5 may be constructed without an outer housing. FIG. 6 depicts a variant of FIG. 5 , with the housing and corresponding housing apertures removed from the apparatus such that the compressed pellets are directly exposed to the well environment. It can be appreciated by those of ordinary skill in the art that the embodiment in FIG. 4 may be similarly constructed without a housing.
Numerous modifications and variations may be made of the structures and methods described and illustrated herein without departing from the scope and spirit of the invention disclosed. Accordingly, it should be understood that the embodiments described and illustrated herein are only representative of the invention and are not to be considered as limitations upon the invention as hereafter claimed.
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A high energy pipe severing tool is arranged to align a plurality of pressure balanced explosive pellets along a unitizing central tube that is selectively separable from a tubular external housing. The explosive pellets are loaded serially in a column and in full view along the entire column as a final charging task. Detonation boosters are pre-positioned and connected to detonation cord for simultaneous detonation at opposite ends of the explosive column. Devoid of high explosive pellets during transport, the assembly may be transported with all boosters and detonation cord connected.
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BACKGROUND
[0001] For the control of important insect pests in agricultural crops a wide range of chemical pesticides have been indiscriminately used for many decades. The long-lasting impact of the chemicals on the non-target organisms, development of insect resistance to chemical pesticides and their hazardous effects on the human and the environment stimulated the interest of the scientists for an alternate control measure through the bio-control means for managing the insect pests as to increase the agricultural productivity. Among the insect pathogens, entomopathogenic nematodes have been considered as exceptionally potential and effective bio-control agents having non-polluting properties, for the control of major insect pests, which cause serious damage to food and fiber crops of agricultural importance.
[0002] Management by eco-friendly methods using entomopathogenic nematodes as bio-control agents has gained momentum in the recent past. Use of entomopathogenic nematodes for the management of insect pests is easy in application, free from environmental pollution and improves soil health, structurally and nutritionally. As entomopathogenic nematodes of the genera Heterorhabditis and Steinernema have a wide distribution and occur in a variety of soil types and habitats, these can be used for insect control as an alternative to chemical insecticides in agriculture. For this purpose mass in vitro rearing of these nematodes on solid culture has been reported.
[0003] The storage of entomopathogenic nematodes (EPN) for control of insect pests has also been reported earlier: Yukawa et al., 1988 (U.S. Pat. No. 4,765,275) reported the methods for storage for transport of nematodes. In this method a cream of infective juveniles mixed with an absorbent and stored under anaerobic conditions for long period of time at low temperature. In 1991 Bedding (U.S. Pat. No. 5,042,427) described storage of infective stage juveniles of entomopathogenic nematodes in homogenous mixture of cream and clay. In 1994 Bedding (WO 1994005150) described the method of storage of third stage infective juveniles of EPN of the genera Steinernema and Heterorhabditis using polyacrylamide gel. Tachibana et al., 1998 (PCT/JP9603067) described, mixture of nematode clay and water preserved at low temperature for several months.
[0004] The present invention relates to the prolonged storage of entomopathogenic nematodes. Entomopathogenic nematodes have several important attributes that make them excellent candidates for biological control of insect pests. They are specialized to carry and introduce symbiotic bacteria into the insect hemocoel, have a broad host range that includes the majority of insect orders and families. Several species can be cultured artificially on a large scale, which makes it possible to commercially produce large quantities. They have a limited impact on non-target organisms and are not disruptive to the environment. Numerous insect pests of different crops are controlled by parasitic nematodes. Insect hosts include several species of root weevils and flea beetles, mint root borer and other species of stem borers, white grubs, and caterpillars. Parasitic nematodes have been used successfully to control insect pests on mint, citrus, cranberry, small fruits, lawn, ornamentals and vegetable crops. Among the insects, pathogens, entomopathogenic nematodes have been considered as exceptionally effective bio-control agents having non-polluting properties.
[0005] The most important families of the nematodes affecting insects include Steinernematidae Chitwood & Chitwood, 1937 and Heterorhabditidae Poinar, 1976. The genera used for biological pesticides are Steinernema (Travassos, 1927) and Heterorhabditis (Poinar, 1976). Several species used in the current study were reported by Shahina & Maqbool (1996) including S. pakistanese Shahina et al., 2001 and S. asiaticum Anis et al., 2002, S. feltiae Filipjev, 1934, Steinernema abbasi Elawad et al., 1997 and Steinernema siamkayai Stock et al., 1998 and two species of the genus Heterorhabditis, H. indica Poinar et al., 1992 and H. bacteriophora Poinar, 1976.
[0006] In this invention, the above mentioned seven virulent nematode species of the genera Steinernema and Heterorhabditis were cultured on mass scale using the chicken offal method (Bedding, 1984). The cultures were stored at 10-15° C. in distilled water with a drop of triton x-100 per 100 ml culture. This technique of mass culturing of infective juveniles (IJs) was used for the first time in Pakistan (Tabassum & Shahina, 2004). These EPNs have a mutualistic association with entomopathogenic bacteria (EPB) belonging to the genera Xenorhabdus (Thomus & Poinar, 1979) and Photorhabdus (Boemare et al., 1993). Three different species of bacteria Photorhabdus luminescence (Thomus & Poinar, 1979), Xenorhabdus nematophila (Akhurst & Boemare, 1988) and X. bovienii (Akhurst & Boemare, 1988) have been reported for the first time from Pakistan (Shahina et al., 2004).
SUMMARY OF INVENTION
[0007] The entomopathogenic nematode viz., S. pakistanese Shahina et al., 2001; S. asiaticum Anis et al., 2002; S. feltiae Filipjev, 1934; Steinernema abbasi Elawad et al., 1997; Steinernema siamkayai Stock et al., 1998; Heterorhabditis indica Poinar et al., 1992 and H. bacteriophora Poinar, 1976 were extracted from soil samples by using Galleria baiting technique (Bedding & Akhurst, 1975). The collected nematode populations were maintained on Galleria mellonella larvae in the laboratory. The adults were obtained by dissecting infected G. mellonella larvae periodically in Ringer solution. Infective Juveniles (IJs) were collected by the White trap method (White, 1927). Nematodes were killed by applying gradual heat, fixed and processed in anhydrous glycerine using the method described by Poinar (1975). Measurements of all specimens were taken by an ocular micrometer. Identification of nematodes was made using morphometric characteristics as given by Nguyen & Smart (1996).
[0008] Entomopathogenic nematodes viz., S. pakistanese; S. asiaticum; S. feltiae; Steinernema abbasi; Steinernema siamkayai; Heterorhabditis indica and H. bacteriophora were reared in monoxenic culture on chicken offal medium described by Bedding (1984). The third infective stage juvenile collects from medium, washed with tap water and were kept in distilled water with a drop of Triton X-100 (a wetting agent that prevents nematodes from striking to the side of the container) or 0.1% formalin and stored on moist autoclaved polyether polyurethane foam. The foam was coated with IJs more than 10 times of foam weight placed in sterilized container and stored in growth chamber at 10-15° C.
[0009] The effect of prolonged storage on infectivity of EPN isolates viz., S. pakistanese; S. asiaticum; S. feltiae; Steinernema abbasi; Steinernema siamkayai; Heterorhabditis indica and H. bacteriophora at 10-15° C. was assessed. Infectivity was tested by using the Galleria Sand Bioassay wherein 25 G. mellonella larvae were placed in a 9 cm Petri dish then covered with the layer of moist sterile sand. Moist sand was obtained by mixing water in the ratio of 10-8% w/w with dried sterile soil. Infective juveniles suspended in 200 μl of sterilized distilled water and distributed evenly on the top of the sand. Six different age groups of infective stage juveniles viz., freshly hatched, 1-12 month old IJs were used. 500 IJs were inoculated to check the mortality of G. mellonella or infectivity of different age groups of infective stage juveniles. For each treatment three replicates were used.
[0010] The result of the experiments reported here of the infectivity of IJs stored at 15-20° C. for various periods from time of emergence from the host cadaver are as follows. The maximum infectivity of EPN isolates viz., S. pakistanense, S. asiaticum, S. feltiae, S. abbasi, S. siamkayai, H. bacteriophora and H. indica was observed in freshly hatched infective stage juveniles. The minimum infectivity was recorded in 8-12 month old storage of 3 rd stage infective juveniles in above mentioned isolates. Twelve month old infective juveniles lost the infectivity to kill the host.
DETAILED DESCRIPTION OF INVENTION
[0011] The monoxenic solid artificial medium (chicken offal) proves useful for large-scale production of these nematodes and is being used globally. The techniques described by Bedding (1984) for the production of nematodes IJs per unit time were followed. With Bedding's method, normally 5-7 million infective juveniles of Steinernema were produced in a single 500 ml flask containing 80 g of chicken offal medium and stored in flasks containing distilled water at 10-15° C. for 1-12 months. IJs as the infective stage juveniles reared in above mentioned media, kept their infectivity for up-to 8 months. The infective juveniles of Steinernematids and Heterorhabditids were stored on moist autoclaved polyether polyurethane foam. The foam was coated with IJs more than 10 times of foam placed in sterilized container and stored in growth chamber at 10-15° C.
[0012] The infectivity of the above mentioned seven species during prolonged storage was analyzed by a three-way ANOVA. The analysis of variance indicated that there were significant differences between infectivity of fresh to 12 months storage IJs (F=23.2; df=7; P=0.05) but among species, there were no significant differences (F=0.05; df=6; P=0.05) that means all seven nematode species were highly infective during fresh to eight months storage.
[0013] Seven entomopathogenic nematode isolates viz., S. pakistanese Shahina et al., 2001; S. asiaticum Anis et al., 2002; S. feltiae Filipjev, 1934; Steinernema abbasi Elawad et al., 1997; Steinernema siamkayai Stock et al., 1998; Heterorhabditis indica Poinar et al., 1992 and H. bacteriophora Poinar, 1976 were reared in monoxenic culture on chicken offal medium described by Bedding (1984). The third infective stage juvenile collects from medium, washed with tap water and were kept in distilled water with a drop of Triton X-100 (a wetting agent that prevents nematodes from striking to the side of the container) or 0.1% formalin and stored on moist autoclaved polyether polyurethane foam. The foam was coated with IJs more than 10 times of foam weight, placed in sterilized container and stored in growth chamber.
[0014] The effect of prolonged storage on infectivity of EPN isolates S. pakistanese Shahina et al., 2001; S. asiaticum Anis et al., 2002; S. feltiae Filipjev, 1934; Steinernema abbasi Elawad et al., 1997; Steinernema siamkayai Stock et al., 1998; Heterorhabditis indica Poinar et al., 1992 and H. bacteriophora Poinar, 1976 at 10-15° C. were tested by using the Galleria Sand Bioassay; wherein, 25 G. mellonella larvae were placed in a 9 cm Petri dish then covered with a layer of moist sterile sand. Moist sand was obtained by mixing water in the ratio of 10-18% w/w with dried sterile soil. Infective juveniles were suspended in 200 μl of sterilized distilled water and distributed evenly on the top of the sand. Six different age groups of infective stage juveniles viz., freshly hatched, 1-12 month old IJs were used. 500 IJs were inoculated to check the mortality of G. mellonella or infectivity of different age group of infective stage juveniles. For each treatment three replicates were used.
[0015] Freshly hatched infective stage juvenile of EPN isolates viz., S. pakistanese; S. asiaticum; S. feltiae; Steinernema abbasi; Steinernema siamkayai; Heterorhabditis indica and H. bacteriophora had maximum infectivity and showed 100% mortality of G. mellonella larvae.
[0016] EPN isolates S. pakistanese; S. asiaticum; S. feltiae; Steinernema abbasi; Steinernema siamkayai; Heterorhabditis indica and H. bacteriophora were tested and two months old storage of infective stage juveniles of above mentioned isolates showed 85, 81, 83, 80, 79, 83 and 79% mortality of G. mellonella larvae, respectively.
[0017] EPN isolates S. pakistanese; S. asiaticum; S. feltiae; Steinernema abbasi; Steinernema siamkayai; Heterorhabditis indica and H. bacteriophora were tested and four months old storage of infective stage juvenile of above mentioned isolates showed 73, 69, 70, 67, 63, 70 and 65% mortality of G. mellonella larvae, respectively.
[0018] EPN isolates S. pakistanese; S. asiaticum; S. feltiae; Steinernema abbasi; Steinernema siamkayai; Heterorhabditis indica and H. bacteriophora were tested and six months old storage of infective stage juvenile of above mentioned isolates showed 55, 54.5 54, 51, 49, 53 and 48% mortality of G. mellonella larvae, respectively.
[0019] EPN isolates S. pakistanese; S. asiaticum; S. feltiae; Steinernema abbasi; Steinernema siamkayai; Heterorhabditis indica and H. bacteriophora were tested and eight months old storage of infective stage juvenile of above mentioned isolates showed 44, 45, 43, 39, 31, 40 and 32% mortality of G. mellonella larvae, respectively.
[0020] EPN isolates S. pakistanese; S. asiaticum; S. feltiae; Steinernema abbasi; Steinernema siamkayai; Heterorhabditis indica and H. bacteriophora were tested and ten months old storage of infective stage juvenile of above mentioned isolates showed 30, 29, 28, 23, 19, 29 and 23% mortality of G. mellonella larvae, respectively.
[0021] EPN isolates Steinernema pakistanese; S. asiaticum; S. feltiae; S. abbasi; S. siamkayai; Heterorhabditis indica and H. bacteriophora were tested and twelve months old storage of infective stage juvenile of above mentioned isolates showed 14, 14, 14, 11, 09, 13, and 11% mortality of G. mellonella larvae respectively.
[0022] It could be concluded that EPN can be successfully cultured on a large scale and could be used under field condition to provide protection to the crops from insects.
REFERENCES
[0023] Akhurst, R. J. & Boemare, N. E. ( 1988 ). A numerical taxonomic study of the genus Xenorhabdus (Enterobacteriaceae) and proposed elevation of the subspecies of X. nematophilus to species. J. Gen. Microbiol., 134: 1835-1845.
[0024] Anis, M., Shahina, F., Reid, A. P. & Janet Rowe ( 2002 ). Steinernema asiaticum sp.n. (Rhabditida: Steinernematidae) from Pakistan. Int. J. Nematol., 12: 220-231.
[0025] Bedding, R. A. (1994). Methods for the storage of Entomopathogenic nematodes. WO Patent No. 1994005150.
[0026] Bedding, R. A. (1991). Storage of Entomopathogenic nematodes. U.S. Pat. No. 5,042,427.
[0027] Bedding, R. A. (1984). Large-scale production, storage and transport of the insect parasitic nematodes Neoaplectana spp. and Heterorhabditis spp. Ann. Appl. Biol., 104: 117-120.
[0028] Bedding, R. A. & Akhurst, R. J. (1975). A simple technique for the detection of insect parasitic rhabditid nematodes in soil. Nematologica, 21: 109-110.
[0029] Boemare, N. E., Akhurst, R. J. & Mourant, R. G. (1993). DNA relatedness between Xenorhabdus spp. (Enterobacteriaceae), symbiotic bacteria of entomopathogenic nematodes and a proposal to transfer Xenorhabdus luminescens to a new genus, Photorhabdus gen. nov. Int. J. Sys. Bacteriol., 43:249-255.
[0030] Chitwood, B. G. & Chitwood, M. B. (1937). An Introduction to Nematology. Monumental Printing Co., Baltimore, Md.
[0031] Elawad, A. S., Ahmad, W. & Reid, A. P. (1997). Steinernema abbasi sp. n. (Nematoda: Steinernematidae) from the Sultanate of Oman. Fun. App. Nematol., 20: 435-442.
[0032] Filipjev, I. N. (1934). Eine new art der gattung Neoplectana Steiner nebst Bemmerkungen uber die systematishe sellung der letzteren. Magasin de parasitologie de I'Institute Zoologique des Sciences de I'USSR. IV. 1934. 229-240.
[0033] Griffin, C. T. (1996). Effect of prior storage conditions on the infectivity of Heterorhabditis spp. (Nematoda: Heterorhabditidae). Fun. App. Nematol., 19: 95-102.
[0034] Nguyen, K. B. and G. C. Smart, Jr. (1996). Identification of entomopathogenic nematodes in the Steinernematidae and Heterorhabditidae (Nematoda: Rhabditida). J. Nematol., 28, 286-300.
[0035] Poinar, G. O. (1976). Description and biology of a new insect parasitic rhabditoid, Heterorhabditis bacteriophora n. gen., n. sp. (Rhabditida: Heterorhabditidae n. fam.) Nematologica, 21: 463-470.
[0036] Poinar, G. 0. Jr. (1975). Entomogenous nematodes. A manual and host list of insect-nematode associations. Leiden, The Netharlands: E. J. Brill, 317 pp.
[0037] Poinar, G. O., Karunakar, G. K. & David, H. (1992). Heterorhabditis indicus n. sp. (Rhabditida: Nematoda) from India: Separation of Heterorhabditis spp. by infective juveniles. Fun. App. Nematol., 15: 467-472.
[0038] Shahina, F., Anis, M., Reid, A. P., Rowe, J. & Maqbool, M. A. (2001). Steinernema pakistanense sp.n. (Rhabditida: Steinernematidae) from Pakistan. Int. J. Nematol., 11: 124-133.
[0039] Shahina, F. & Maqbool, M. A. (1996). Isolation of entomopathogenic nematodes (Heterorhabditidae and Steinernematidae) from Pakistan. Pak. J. Nematol., 14: 135-136.
[0040] Stock, S. P., Somsook, V. & Ried, A. P. (1998). Steinernema siamkayai n. sp. (Rhabditida: Steinernematidae) an entomopathogenic nematode from Thailand. Sys. Parasitol., 41: 105-113.
[0041] Tabassum, K. A. & Shahina, F. (2004). In vitro mass rearing of different species of entomopathogenic nematodes in monoxenic solid culture. Pak. J. Nematol., 22: 167-175.
[0042] Tachibana, M., Indrasith, L. Suzuki, N. & Asano, I. (1998). Process for producing entomopathogenic nematode preparation and method of storing the same. PCT. JP9603067.
[0043] Travassos, L. (1927). Sobre O genera oxysomatium. Bol. Biol. Sao Paolo, 5: 20-21.
[0044] Thomas, G. M. & Poinar, G. O. Jr. (1979). Xenorhabdus gen. nov., a genus of entomopathogenic nematophilic bacteria of the family Enterobacteriaceae Int. J. Sys. Bacteriol., 29: 352-360.
[0045] White, G. F. (1927). A method for obtaining infective nematode larvae from cultures. Science, 66: 302-303.
[0046] Yukawa, Pitt, Janice, M., Takao ( 1988 ). Nematode storage and transport. U.S. Pat. No. 4,765,275.
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This invention relates to methods of prolonged storage of the species of entomopathogenic nematodes belonging to the genera of Steinernema and Heterorhabditis for use as bio-pesticides wherein storage in surfactant solution or antimicrobial solution on sterilized polyurethane foam allows maintaining infectivity of at least 50% for six months at 10-15 C storage conditions.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to novel benzo[b]furancarboxamide derivatives, stereo-isomers thereof, process for the preparation of same, and medicine for improving hypermotility of digestive tract, which contains the compound or salt as an effective ingredient.
2. Related Arts
Since 4-amino-5-chloro-N-[(2-diethylamino)ethyl]-2-methoxybenzamide [General name: Metocloplamide ("The Merck Index", 10th Ed. 6063)] had been developed in the 1960s, as an agent for improving hypermotility of digestive tract or anti-vomiting agent, various benzamide derivatives have been synthesized to evaluate pharmacological effect thereof. The main object for developing such derivatives lies in moderating a side effect of Metoclopramide to central system due to its anti-dopamine action, namely extrapyramidal disorder and cryptorrhea (lactation and prolactinemia), and recent years, various reports have been issued on development of derivatives having antagonism to serotonin receptor. A relation between a selective action and structure of these benzamide derivatives has not sufficiently been elucidated, but it has been recognized that a mutual relation between a substituent to amide nitrogen and alkoxy group at 2-position is important [for instance, Jap. Pat. No. Sho 62 (A.D. 1987 )--129279 (A) and "J. Med. Chem.", Vol. 34, page 616 (1991 )]. Under such a technical notion, carboxamide derivatives of benzofuran and benzopyran have been studied, as compounds analogous to the benzamide derivatives [Jap. Pat. Nos. Sho 60 (A.D. 1985--169473(A), Sho 62 (A.D. 1987)--234083(A), Hei 1 (A.D. 1989)--104272(A), Hei 1 (A.D. 1989)--110684(A), Hei 1 (A.D. 1989)--168686, Hei 1 (A.D. 1989)--501226(A) and Hei 4 (A.D. 1992)--295476(A)].
SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel compound which has excellent or powerful action to improve hypermotility of digestive tract and no or weak side effect to central system, and thus is excellent in effectiveness and safety.
The inventors have energetically studied and investigated to finally found that certain benzo[b]furancarboxamide derivatives are suitable for attaining the object, so that the invention was established.
The benzo[b]furancarboxamide derivatives are shown by a formula of ##STR2## wherein R 1 , R b , R c and R d are a hydrogen atom or lower alkyl group, respectively; R e is a hydrogen atom, amino radical, lower alkylamino group or acylamino group; X is a hydrogen atom or halogen atom; and n is an integer of 1-5.
According to a process of the invention, the derivatives (I) and salts thereof can be prepared by reacting a compound of the formula ##STR3## wherein R a , R b , R c , R d and R e have the meanings as referred to,
or a reactive derivative thereof with a compound of the formula ##STR4## wherein n has the meaning as referred to, and if necessary, converting a reaction product into the salt.
In connection with the compounds (I), the lower alkyl group is such a straight- or branched-chain alkyl group as methyl, ethyl propyl, isopropyl, butyl, heptyl and hexyl. As examples of the acylamino group, acetylamino and propionylamino radicals may be listed. The halogen atom may be of fluorine, chlorine, bromine or iodine.
The salt of the compounds (I) means, of course, pharmacologically acceptable one, and hydrochloric acid, sulfuric acid, hydrobromic acid or the like inorganic acid; and fumaric acid, oxalic acid, maleic acid, malic acid, tartaric acid, methanesulfonic acid or the like organic acid can be listed as that for forming the salt.
As the reactive derivative of compound (I), a lower alkyl ester, active ester, acid anhydride, acid halide (especially acid chloride) or the like may be listed. As the active ester, p-nitrophenyl ester, 2,4,5-trichlorophenyl ester, pentachlorophenyl ester, cyanomethyl ester, N-hydroxysuccinic imide ester, N-hydroxy-5-norbornen-2.3-dicarboxyimide ester, N-hydroxypiperidine ester, 8-hydroxyquinoline ester, 2-hydroxyphenyl ester, 2-hydroxy-4,5-dichlorophenyl ester, 2-hydroxypyridine ester and 2-pyridylthiol ester can be exemplary listed. As the acid anhydride, a symmetrical acid anhydride or mixed acid arthydride can be employed. As the mixed acid anhydride, any mixture of ethyl chlorocarbonate, isobutyl chlorocarbonate, benzyl chlorocarbonate and the like chlorocarbonic acid esters, or a mixture of the ester with an alkane acid such as isovaleic acid, pivalic acid or the like.
For the reaction between the compounds (II) and (III), a dehydration condensing agent may be added. Such an agent may be listed therefor as dicyclohexylcarbodiimide, hydrochloride of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N,N'-carbonyldiimidazole, 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline or the like organic condensing agent; and phosphorous trichloride, phosphorous pentachloride, phosphorous oxychloride, thionyl chloride, silicon tetrachloride or the like inorganic condensing agent.
The reaction of the compound (II) or its reactive derivative with the compound (III) can be carried out by stirring for 0.5-24 hours at -30°-+150° C. in an inert solvent. Such a solvent may be exemplary listed as benzene, toluene, xylene or the like aromatic hydrocarbon; diethylether, tetrahydrofuran, dioxane or the like ether; methylene chloride, chloroform or the like halogenated hydrocarbon; pyridine, quinoline, ethyl acetate, acetonitrile, dimethylformamide, dimethylsulfoxide, acetone, ethylene glycol, water, or a mixture of the above. If necessary, the reaction may be carried out in the presence of a base such as sodium carbonate, potassium carbonate or the like alkali carbonate; sodium hydrogen carbonate or the like alkali hydrogen carbonate; sodium hydroxide, potassium hydroxide or the like alkali hydroxide; triethylamine, N-methylmorpholine, N,N-dimethylaniline, pyridine, quinoline or the like tertiary amine. In lieu of separate addition of the base, the compound (III) may be used in excess amount.
The compound shown by Formula (I) and having optical activity can be prepared according to the process as referred to above, but starting from the compound shown by Formula (II) and having optical activity, or by subjecting the racemic compound (II) to optical resolution, in accordance with a conventional method. As the method for carrying out the optical resolution, there are one preparing a salt with an optically active acid (for instance, tartaric acid, dibenzoyl tartaric acid, mandelic acid, camphor-10-sulfonic acid or the like), by utilizing a fact that the racemic compound (I) shows an alkalicity and then subjecting the resulting diastereomers to resolution, a method using a column which separates optical isomers, and the like.
The starting compounds (II) and (III) can be synthesized by methods described, for instance, in Jap. Pat. Nos. Sho 62 (A.D. 1987)--234083(A), Sho 62 (A.D. 1987)--277376(A) and Hei 1 (A.D. 1989)--110684 as well as that described by Miyano et al [" 98 (which can be translated as --Abstract of the 98th Annual Lecture Meeting in the Pharmacological Society of Japan--)", page 223 (1978)], respectively. The compound shown by Formula (II) and having optical activity can be obtained by subjecting the racemic compound (II) to optical resolution in accordance with a method known per se. As the method for carrying out the optical resolution, there are one preparing a salt with an optical active base (for instance, cinchonine, cinchonidine, brucine, quinine, α-methylbenzylamine or the like), by utilizing a fact that the racemic compound (II) shows an acidity and then subjecting the resulting diastereomers to resolution, a method using a column which separates optical isomers, and the like.
When a medicine shall be prepared by using the compound (I) or salt thereof as an effective ingredient, there is no limitation in form of the medicine and thus it can be made into a tablet, pill, capsule, powder, granule, suppository or the like solid preparation; or a solution, suspension, emulsion or the like liquid preparation. For preparing the solid preparation, a starch, lactose, glucose, calcium phosphate, magnesium stearate, carboxymethyl cellulose or the like filler can be used and if necessary, a lubricant, disintegrator, coating agent, coloring matter may also be used. The liquid preparation may contain a stabilizer, dissolution aid, suspending agent, emulsifier, buffer, preservative or the like.
An amount of dose of the compound (I) or salt thereof varies depending on a selected kind of the same, form of the medicine, symptom, age of a patient and other factors, but in general, such a range of about 0.01--about 50 mg/day is preferable for an adult.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The invention will now be further explained in more detail with reference to Manufacturing Examples, Pharmacological Test Examples and Medicine Preparation Examples.
EXAMPLE 1
4-Amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2,3-dihydrobenzo[b]furan-7-carboxamide
Into an agitating solution of 4-amino-5-chloro-2,3-dihydrobenzo[b]furan-7-carboxylic acid (3.21 g) in absolute tetrahydrofuran (50 ml), was added little by little 1,1-carbonylimidazole (2.43 g) and after lapsed 1 hour, a solution of 5-(2-aminoethyl)-1-azabicyclo[3.3.0]octane (2.31 g) in absolute tetrahydrofuran (2 ml) was added therein to reflux for 1 hour. After cooled, the solvent was distilled out in vacuo, a residue was dissolved into chloroform, washed with saturated sodium hydrogen carbonate solution and then water, and thereafter, the solvent was distilled out in vacuo. The resulting residue was refined by alumina column chromatography (developing solvent: chloroform) to afford 4.1 g of the titled compound.
Melting point: 124.5° C.
Mass spectrum (EI/DI) m/z: 349 (M + ), 110.
IR spectrum; v (KBr, max) cm -1 : 3395, 1625.
NMR spectrum (CDCl 3 ) δ ppm: 1.50-1.85 (10H, m), 2.50-2.65 (2H, m), 2.93-3.08 (2H, m), 3.05 (2H, m), 3.42-3.54 (2H, m), 4.21 (2H, broad), 7.87 (1H, s), 8.28 (1H, broad).
EXAMPLE 2
4-Amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxamide
By treating as described in Example 1 excepting that 4-amino-5-chloro-2-methyl-2,3- dihydrobenzo[b]furan-7-carboxylic acid (5.0 g) was selected as a starting compound, the titled compound (6.68 g) was obtained.
Melting point: 127°-129° C.
Mass spectrum (EI/DI) m/z: 3 (M + ), 110.
IR spectrum; v (KBr, max) cm -1 : 3395, 1620.
NMR spectrum (CDCl 3 ) δ ppm: 1.52 (3H, d), 1.52-1.83 (10H, m), 2.55-2.68 (3H, m), 2.97-3.06 (2H, m), 3.16 (1H, double d), 3.45-3.53 (2H, m), 4.18 (2H, broad), 5.07-5.15 (1H, m), 7.99 (1H, s), 8.79 (1H, broad).
The resulting free base was treated with fumaric acid in ethanol to obtain corresponding 1/2 fumarate in quantitative amount.
Melting point: ˜200° C. (dec.).
REFERENCE EXAMPLE
(+)- and (-)-4-Amino-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid
4-Amino-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid (5.0 g) and anhydrous brucine (8.3 g) were added into methanol (200 ml) to heat the same for dissolving the compounds. Then, formed crystals were obtained by filtration and recrystallization from methanol was repeated to afford brucine salt of 4-amino-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid. The salt was treated by sodium hydroxide and hydrochloric acid to obtain (+)-4-amino-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid (200 mg) which was dissolved into N,N-dimethylformamide (1.5 ml) and N-chlorosuccinic imide (119 mg) was added to stir the mixture for 1 hour at 70°-80° C. The reaction solution was poured into an ice and water to obtain by filtration formed crystals which are (+)-4-amino-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid and can be obtained in quantitative amount.
While, the aforesaid methanol solution (filtrate) was concentrated and refined, and then treatments similar to the above were carried out to obtain (-)-4-amino-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid.
EXAMPLE 3
(-)-4-Amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxamide . 1/2 fumarate
By treating as described in Example 1 excepting that (+)-4-amino-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid (200 mg) obtained by the Reference Example was selected as a starting compound, (+)-4-amino-N-[2-(1-azabicyclo[3.3.0]octan-5yl)ethyl]-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxamide (240 mg) was obtained.
The free base was treated with fumaric acid in ethanol to obtain the titled salt in quantitative amount.
Melting point: ˜200° C. (dec.).
[α] D : -3.20° (c=5, methanol:water=1:1).
EXAMPLE 4
(+)-4-Amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxamide . 1/2 fumarate
By treating as described in Example 1 excepting that (-)-4-amino-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid (300 mg) obtained by the Reference Example was selected as a starting compound, (-)-4-amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxamide (350 mg) was obtained.
The free base was treated with fumaric acid in ethanol to obtain the titled salt in quantitative amount.
Melting point: ˜200° C. (dec.).
[α] D : +3.46° (c=5, methanol:water=1:1).
EXAMPLE 5
4-Amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro -2,2-dimethyl-2,3-dihydrobenzo[b]furan-7-carboxamide
By treating as described in Example 1 excepting that 4-amino-5-chloro-2,2-dimethyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid (4.08 g) was selected as a starting compound, the titled compound (5.63 g) was obtained.
Melting point: 189°-191° C.
Mass spectrum (EI/DI) m/z: 377 (M + ), 110.
IR spectrum; v (KBr, max) cm -1 : 3327, 1622.
NMR spectrum (CDCl 3 ) δ ppm: 1.54 (6H, s), 1.55-1.89 (10H, m), 2.56-2.64 (2H, m), 2.84 (2H, s), 2.98-3.07 (2H, m), 3.45-3.53 (2H, m), 4.17 (2H, broad), 7.76 (1H, broad), 7.88 (1H, s).
EXAMPLE 6
4-Amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2,3-dimethyl-2,3-dihydrobenzo[b]furan-7-carboxamide and its 1/2 fumarate
By treating as described in Example 1 excepting that 4- amino-5-chloro-2,3-dimethyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid (100 mg) was selected as a starting compound, 4-amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2,3-dimethyl-2,3dihydrobenzo [b]furan-7-carboxamide (134 mg) was obtained. The free base was treated with fumaric acid in ethanol to obtain its 1/2 fumarate in quantitative amount.
Melting point: 227°-234° C.
Mass spectrum (EI/DI) m/z: 377 (M + ), 110.
NMR spectrum (DMSO-d 6 ) δ ppm: 0.96 (3H, t), 1.57-1.90 (12H, m), 2.63-2.77 (3H, m), 3.00-3.70 (5H, m), 4.87-4.99 (1H, m), 5.70 (2H, broad s), 6.46 (1H, s), 7.47 (1H, s), 7.82 (1H, broad t).
EXAMPLE 7
4-Amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2-ethyl-2,3-dihydrobenzo[b]furan-7-carboxamide and its 1/2 fumarate
By treating as described in Example 1 excepting that 4- amino-5-chloro-2-ethyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid (100 mg) was selected as a starting compound, 4-amino-N-[2-(1azabicyclo [3.3.0]octan-5-yl)ethyl]-5-chloro-2-ethyl-2,3dihydrobenzo [b]furan-7-carboxamide (84 mg) was obtained. The free base was treated with fumaric acid in ethanol to obtain its 1/2 fumarate in quantitative amount.
Melting point: 174°-176° C.
Mass spectrum (EI/DI) m/z: 377 (M + ), 110.
NMR spectrum (DMSO-d 6 ) δ ppm: 0.98, 1.19, 1.31, and 1.45 (6H, each d), 1.62-1.91 (10H, m), 2.69-2.77 (2H, m), 3.00-3.70 (5H, m), 4.61, and 4.87 (1H, each m), 5.68, and 5.75 (1H, each broad d), 6.45 (1H, s), 7.48, and 7.50 (1H, each s), 7.87, and 7.98 (1H, each broad t).
EXAMPLE 8
4-Acetylamino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxamide
By treating as described in Example 1 excepting that 4-acetylamino-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid (100 mg) was selected as a starting compound, the titled compound (145 mg) was obtained.
Mass spectrum (EI/DI) m/z: 405 (M + ), 110.
NMR spectrum (CDCl 3 ) δ ppm: 1.52 (3H, d), 1.52-1.83 (10H, m), 2.23 (3H, s), 2.58-2.64 (3H, m), 2.87 (1H, double d), 3.00-3.04 (2H, m), 3.34 (1H, double d), 3.52 (2H, q), 5.05-5.13 (1H, m), 7.26 (1H, broad), 7.98 (1H, s), 8.39 (1H, broad).
EXAMPLE 9
N-[2-(1-Azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro -2-methyl -2,3-dihydrobenzo[b]furan-7-carboxamide
By treating as described in Example 1 excepting that 5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxylic acid (100 mg) was selected as a starting compound, the titled compound (155 mg) was obtained.
Mass spectrum (EI/DI) m/z: 349 (M + ), 110.
NMR spectrum (CDCl 3 ) δ ppm: 1.57 (3n, d), 1.52-1.83 (10n, m), 2.56-2.62 (2H, m), 2.87 (1H, double d), 2.98-3.04 (2H, m), 3.36 (1H, double d), 3.48-3.56 (2H, q), 5.03-5.09 (1H, m), 7.20, and 7.89 (1H, each d), 7.98 (1H, s), 8.35 (1H, broad t).
EXAMPLE 10
4-Amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-2-methyl -2,3-dihydrobenzo[b]furan-7-carboxamide
A mixture of 4-amino-N-[2-(1-azabicyclo[3.3.0]octan-5yl)ethyl]-5-chloro-2-methyl-2,3-dihydrobenzo[b]furan-7-carboxamide (100 mg) obtained by Example 2, 20% Pd-C (catalystic amount) and ethanol was stirred under hydrogen gas atmosphere for 20 hours. Then, the catalyst was removed by filtration and the solvent was distilled out in vacuo to afford the titled compound in quantitative amount.
Mass spectrum (EI/DI) m/z: 329 (M + ), 110.
NMR spectrum (CDCl 3 ) δ ppm: 1.52 (3H, d), 1.52-1.87 (10H, m), 2.55-2.66 (3H, m), 2.98-3.06 (2H, m), 3.13 (1H, double d), 3.46-3.53 (2H, m), 3.82 (1H, broad s), 5.02-5.10 (1H, m), 6.27, and 7.77 (1H, each d), 7.92 (1H, broad t).
PHARMACOLOGICAL TEST EXAMPLE 1
Action on Hypermotility of Digestive Tract
The compounds obtained by Examples 1, 2 and 5 as well as exemplar known compounds (Metocloplamide and Cysapride) were selected as Test Compounds, and an action of the compounds for accelerating gastric emptying was checked in accordance with the method described by Yokochi et al [" (which can be translated as --Bulletin of Pharmacological Society of Japan--)", Vol. 92, page 297 (1988 )].
Namely, the test compound was orally administered in an amount of 0.3, 1.0, 3.0 or 10 mg/kg to rats fasted for 24 hours, and after 30 minutes from the administration, a coloring matter in a constant amount (phenol red, 100 μg) was also orally administered. After 15 minutes from the administration of coloring matter, gastric pylorus and cardia were ligated to exentrate a stomach and to measure an amount of the coloring matter remaining in the stomach through a measurement of absorbance at 560 nm for calculating a rate of gastric emptying and rate of its acceleration., in accordance with following equations, so that an effective amount (ED 50 ) was determined.
Rate of gastric emptying=100-(B/A)×100
A: Dosing amount of coloring matter, and
B: Remaining amount of coloring matter.
Rate of acceleration=(C-D)×100
C: Rate of gastric emptying in Test Group, and
D: Rate of gastric emptying in Control Group given no Test Compound.
Results are shown in following Table 1. As apparently seen therefrom, each of the compounds according to the invention shows an action for accelerating gastric emptying far excellent from that of the known compounds.
TABLE 1______________________________________ ED.sub.50Test Compound (mg/kg)______________________________________Example1 2.152 1.975 1.50Metoclopramide 16.3Cisapride 6.37______________________________________
PHARMACOLOGICAL TEST EXAMPLE 2
Agonisting Action to 5-HT 4 Receptor
Each of the compounds obtained by Examples and Cysapride (exemplar known compound which has been said as having a strong agonisting action to 5-HT 4 receptor) were selected as Test Compounds and Control compound, and agonisting action thereof was checked in accordance with the method described by Baxter et al "Naunyn-Schmiederberg's Arch. Pharmacol.", Vol. 343, page 439 (1991)].
Namely, a relaxation of the Test and Control compounds in various concentration showing to carbachol contradiction of a muscular sample of mucous membrane in esophgus exentrated from a rat was checked to calculate a concentration causing 50% relaxation and compared with its negative logarithm ( P EC 50 ). Results are shown in following Table 2. Therefrom, it has been found that the compounds according to the invention show the agonisting action to 5-HT 4 receptor, which is compatible to or excellent than the Control Compound.
TABLE 2______________________________________Compound .sub.P EC.sub.50______________________________________Example1 6.52 (*) 7.43 7.74 7.35 6.56 7.97 7.78 6.59 7.010 6.0Cisapride 7.4______________________________________ In the Table, *: 1/2 fumarate.
PHARMACOLOGICAL TEST EXAMPLE 3
Anti-Dopamine Action
The compounds obtained by Examples 1, 2 and 5 as well as known compounds (Metocloplamide and Cysapride) were selected as Test and Control Compounds, respectively. The compound was orally administered to rats in amount of 100, 300 or 1000 mg/kg to observe for 2 days general symptoms including catalepsy and blepharoptosis due to antagonistic action of the compound to dopamine D 2 receptor. Results are shown in following Table 3. As apparently seen therefrom, no anti-dopamine action was recognized on the compounds according to the invention.
TABLE 3______________________________________ Influence on central nervous system (.sup.a)Compound 100 mg/kg 300 mg/kg 1000 mg/kg______________________________________TestExample 1 - 2 - - - 5 -ControlMetoclopramide ++Cisapride ++______________________________________ In connection with (.sup.a), -: No influence, +: Noticeable influence, and ++: Somewhat remarkable influence.
MEDICINE PREPARATION EXAMPLE 1 (TABLET)
Tablets were prepared in conventional manner and by using following ingredients.
______________________________________Compound (Example 1) 2.0 (mg)Lactose 136.0Corn starch 60.0Magnesium stearate 2.0 200.0 mg/tablet______________________________________
MEDICINE PREPARATION EXAMPLE 2 (INJECTION)
An injection was prepared in conventional manner and by using following ingredients. The injection was charged into ampules under aseptic condition to heat seal the ampules. When it shall be used, the solution in the ampule may be diluted with a saline for injection.
______________________________________Compound (Example 2, 1/2 fumarate) 0.05 (mg)Sodium chloride 8.00Distilled water for injection Remainder 1.0 ml/ampule______________________________________
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There are disclosed a benzo[b]furancarboxamide derivative of the formula ##STR1## wherein R a , R b , R c and R d are a hydrogen atom or lower alkyl group, respectively; R e is a hydrogen atom, amino radical, lower alkylamino group or acylamino group; X is a hydrogen atom or halogen atom; and n is an integer of 1-5,
and including racemic compounds and stereo-isomers thereof, a salt of the compounds, a process for the preparation of the compounds and salts as well as use thereof for improving hypermotility.
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FIELD OF THE INVENTION
The invention relates to radiation curable release coatings suitable for various release applications which are free of silicone release agents. The invention includes the formulation of polymerizable coating compositions and the cured coating film or sheet produced therefrom. The invention includes coating compositions useful for transfer coating applications.
BACKGROUND OF THE INVENTION
Radiation curable coatings differ in their adherence to the various plastic, metallic and paper substrates used in commerce. This difference in adherence can be applied to transferring a coating from one substrate having a relatively weak adhesive bond to a second substrate having a stronger bond.
One set of applications based on that concept is substitution of low cost substrates readily available in commerce for the expensive release substrates currently used for this purpose. Furthermore, the surface texture of the carrying web may be desirably imparted to the cured coating. In this way any of a number of aesthetically pleasing and decorative effects can be produced. In addition, when using a nonporous substrate as the carrying web for transfer of the coating composition to a porous substrate, the quantity of coating required is greatly reduced due to the minimization of wicking of the uncured coating into the porous substrate. The result is a coating which resides largely on the surface of the porous substrate, thus more easily bridging the irregularities of that surface with a minimum of coating material. A particularly good example of this process is the transfer of a coating composition from a polyester web to paper to provide a smooth glossy surface for subsequent vacuum metallization. The metallized surface obtained in this manner is exceptionally shiny and free from flaws and blemishes.
In alternative applications, the substrate can be used as interleaves between plastic sheets, temporary backings for pressure-sensitive adhesives, and papers used as temporary carriers in film and foam casting processes. The release papers may be smooth or embossed, to impart any desired texture to the film or the foam cast against them. They may also be preprinted with an ink that is transferred to the cast film.
SUMMARY OF THE INVENTION
The invention relates to providing a formulation which is free of silicone as a release agent, which is liquid, which is curable by electron beam or ultraviolet radiation and which contains at least 5.0 weight percent of polytetrafluoroethylene polymer in particulate form. The formulation comprises acrylo monomers and oligomers of both monofunctional and trifunctional acrylate monomers which can be conveniently cured by irradiation.
DETAILED DESCRIPTION OF THE INVENTION
The monomer containing formulations of the invention contain acrylate monomers and oligomers based on acrylates. The acrylate can be monofunctonal or trifunctional; these monomers can be cured by electron beam or ultraviolet radiation. The acrylate can be selected from the group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, methylacrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 1,4-butylene dimethacrylate. Oligomers which can be used as the acrylate source in formulations of the invention include acrylated epoxy resins (Bisphenol A type).
The formulations of the invention are solutions of the acrylate monomer. The solvents for the formulations can be selected from those including benzene, ethyl acetate, ethylene dichloride, butyl acetate, methyl isobutyl ketone, toluene and admixtures thereof. The solution formulation can contain 5 to 50 weight percent of monomer.
The formulation contains small amounts of fluoropolymer sufficient to facilitate removal of the cured coating of the formulation from a carrying web without adversely affecting the physical integrity of the cured coating. The amount of the fluoropolymer in the formulation can range from 2 to 10 weight percent. The fluoropolymer is in particulate form. The particule size of the fluoropolymer can range from 0.1 microns to 10 microns. The particule size of the fluoropolymer is such that the fluoropolymer is a powder. Preferably, the fluoropolymer is Teflon. Inclusion of the powder fluoropolymer obviates the art recognized expedient of employing lubricants referred to as internal lubricants which are used in release coatings to reduce the surface coefficient of friction. Thse art recognized internal lubricants include waxes, hydrocarbon oils, and silicones, which can detrimentally alter the physical properties of the cured coating.
In accordance with the invention the inclusion of the fluoropolymer powder in the formulation of the invention reduces the surface coefficient of friction. Accordingly, that inclusion has been found useful to control, generally to reduce, the adhesive force of the cured coating, thereby facilitating removal therefrom of the carrying web. Care must be taken, however, not to incorporate an undue amount of such materials into the coating composition, as adhesion to the substrate of interest may be adversely affected and it may make the subsequent application of decorative inks or other materials to the cured coating more difficult.
The formulation of the invention which is rendered a radiation cured release coating is done so on a carrying web. The carrying web may be ordered according to the peel force required to separate it from the substrate of interest. In general, the carrying web may be a polyolefin, polyester, metal or paper used in commerce will perform well as carrying webs exhibiting low peel strength.
The desired physical, chemical and aesthetic properties of the coating required for the intended use on the substrate of interest is decided and a suitable formulation developed. Application of the coating to varous plastic, paper and metal film materials which might be useful as carrying webs is then performed. In accordance with the invention, the coated carrying web may be brought into contact with an ultimate substrate of interest.
If the film or sheet produced by radiation curing in accordance with the invention is to be simultaneously, with said curing, adhered to a substrate, other than the carrying web, a sandwich of said other substrate, said carrying web and the formulation of the invention disposed therebetween is formed. In such an application the adhesive force between the cured coating and the substrate of interest may be modified. An initial consideration to such modification is the crosslink density of the coating composition, as conveniently defined by the calculated (i.e., theoretically possible) number of gram moles of potential branch points per 100 grams of coating composition; one may controllably effect a decrease in the adhesive bond strength between the cured coating and most substrates of interest in commerce. Crosslink densities ranging from about 0.02 to about 1.0 have been found to be useful in this regard, but a range of from about 0.03 to 0.7 is preferred and, in particular, a range of between 0.04 and 0.5 is found to be the most useful. Given a calculated potential crosslink density in the coating composition, the adhesive force between the cured coating and the substrate of interest may be further modified by incorporating into or eliminating from the composition specific chemical groups that influence the adhesive bond to the substrate. Such chemical groups may be broadly classified as Lewis & Bronsted acids or bases, hydroxyl or carboxyl groups combined with organic hydrocarbon molecules, ether linkages, urethane linkages, epoxide groups, and mercaptan groups. Incorporation of adhesion promoting groups on the surface of the substrate on which the cured coating is to remain after stripping away of the carrying web can be undertaken. This may be accomplished by subjecting the substrate of interest to oxidizing or reducing atmospheres, or by any other suitable chemical or heat treatment. Physical treatment of the surface of the uncoated substrate with abrasives which serve to improve mechanical adhesion may also be used on nonporous substrates to improve the adhesive bond.
Increasing the crosslink density of the coating will provide lower stripping forces and a correspondingly greater variety of carrying webs. Decreasing the crosslink density will have the opposite effect. In any specific process it is desirable that a compromise between adhesion to the substrate and the carrying web be reached.
The preferred range of crosslink densities described above provides coatings that demonstrate good adhesion to paper and vinyl film, while releasing acceptably from polyolefin, polyester, and "oil" metal films. The lower portion of the range also includes compositions that adhere well to treated polyethylene and clean metals, while stripping easily from polyolefin, polyester and "oily" metal films.
The order in the array may be altered by surface treatment. For example, if it is desired to transfer from polyester to polyethylene or metal films, the polyethylene may be subjected to Corona discharge, or the metal film may be cleansed of the oils and soaps used in the manufacturing process by suitable washing, heating treatment, or by Corona discharge treatment.
The coated carrying web or the sandwich formed thereby is then subjected to appropriate curing means (electron beam or UV) and the coating composition polymerized. In case of cure by electron beam, the composition of the carrying web is not critical since penetration by the electrons can be assured by selection of sufficiently high voltage. In the case of cure by ultraviolet light, however, the selection of carrying web must be confined to films that transmit UV light in sufficient intensity to effect the cure of the coating. Thus, polyolefins, particularly polyethylene, are preferred for use with UV cure coatings due to the excellent transmission of UV light. The range of materials tha can be used as carrying webs can be extended by using UV initiators that absorb strongly in regions where UV transmission is highest. Thus, polyester film can be used with UV cure coatings by use of photo initiators such as 2-chlorothioxanthose which absorbs light at the higher wavelengths. In addition, mixtures of molecules containing one or more epoxide groups per molecule may be cured by ultraviolet light using appropriate UV sensitive initiators. Such initiators are well known in the coating art. It is found that polyethylene is a particularly efficient carrying web for use with coatings compositions utilizing the epoxide cure mechanism.
The invention is illustrated by the following examples:
EXAMPLES
An electron beam (EB) curable binder containing oligomers based on acrylated epoxy resin (Bisphenol A type) and both monofunctional and trifunctional acrylate monomers which can be conveniently EB cured at 3 Mrads in an inert atmosphere to a crosslinked film served as the coating binder for this example. Small amounts of finely divided flouropolymer (about 5%) can be conveniently dispersed into the coating. Drawdowns onto 42 lb. super calendared paper applying about 3#/Ream (3 g/1000 sq. in.) (5 g/meter 2 ) could be EB cured using an ESI Lab Electrocurtain. Subsequent testing of the release properties of the EB cured coatings gave the following table:
______________________________________ RELEASE g/in PSACOATING COMPOSITION MAGIC TAPE LABEL______________________________________Goldschmidt RC-450 100% silicone 20 30V-26 base sol'n, 100% acrylate- paper tear paper tearno additiveV-26A 5% SST-3 Teflon powder 60 50V-26C 5% Flourolube F Teflon 15 50powderV-26D 5% Silicone blend - No 80 paper tearTeflon______________________________________
As shown, the addition of as little as 5% finely divided fluoropolymer gives the release properties to a 100% acrylate based silicone free radiation cured coating. Fluorolube F is also a Teflon powder but is a much finer particle size.
Obviously, with proper photo initiators, these same coatings could be cured with Ultra Violet light with similar results.
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The invention relates to acrylate polymer and copolymer release coatings containing amounts of polyfluoropolymer powder sufficient to alter the adhesion of the release coating on a support after radiation curing of the formulation producing said coating.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a leader angle control device for a civil foundation engineering works machine, for example, a pile driver, an earth auger, and so forth.
2. Description of the Prior Art
FIGS. 1 and 2 show a pile driver, wherein an upper body 2 of the pile driver 1 is rotatably mounted on a tractor (typically caterpillar type) 3, and a leader 5 is mounted on a bracket 4 rigidly held to the front part of the turning assembly 2, the leader 5 being supported by two backstays 6 and 7 having backstay cylinders 6a and 7a respectively. The tops of the backstays 6 and 7 are pivotally attached to the upper positions 5a and 5b of the leader 5 respectively, and the bottoms of the backstays 6 and 7 are pivotally held to points S and T in the rear side parts of the upper body. The bottom part of the leader 5 is pivotally mounted on the front end 4a of the bracket 4. The two back-stay cylinders 6a and 7a are designed to keep the leader 5 in the vertical position by the extend/retract control. For bringing the leader 5 in the vertical position, a person measures the inclination angle of the leader 5 from the front, rear, left or right of the leader 5 at a certain distance from the pile driver 1 using a transit or other suitable means, the measuring person then notifies the operator of the direction in which the leader 5 is to be moved for the correction of inclination by signalling, and in response to the signal the operator operates a backstay cylinder control lever by hand, thus controlling the left and right backstay cylinders 6a and 7a.
The prior art method described above has such drawbacks as that it requires a person to measure the inclination angle in addition to the pile driver operator, and the vertical setting of the leader is a difficult and time-consuming work. Another type of the leader angle control device is known in the art. This device uses nine divided areas in vertical view. Due to the area which upper portion of the leader belongs to, operation of both stay cylinders, that is, extension, retraction and stop are uniquely determined. The area to which the leader belongs is logically judged by a logical circuit to which output signals from the inclinometers are applied.
The device, however, the course which the upper portion of the leader follows to return to the vertical position is of L form. Therefore the distance of the course is long and thus time required to return to the vertical position is long. The device has the disadvantage that it is difficult to eliminate the dangerous state of the leader.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a leader angle control device capable of speedy and safe leader vertical alignment.
Another object of the present invention is to provide a leader angle control unit designed to indicate the working length of the backstay cylinder to be controlled at all times.
Still another object of the present invention is to provide a leader angle control device capable of maintaining the stability of the foundation civil engineering works machines by keeping the acceleration to be applied to the leader at the control start-up small through the temporary reduction of the control system deviation at the automatic control start-up and the gaining of the true value by the gradual increase with time.
Still another object of the present invention is to provide a highly safe leader angle control device which allows the operator to know the inclination of the leader easily on the indicator and can help to enhance the work efficiency.
According to a preferred embodiment of the present invention, the leader angle control device comprises two inclinometers for measuring the leader inclinations in two different directions, an arithmetic unit for calculating the working length of each backstay cylinder to be corrected based on the detected inclination angle, and a means to control the flow of the backstay cylinder driving oil.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the invention will be made with reference to the accompanying drawings, wherein same numerals designate corresponding parts in the several figures.
FIG. 1 is a side view of the pile driver.
FIG. 2 is a front view of the pile driver.
FIG. 3 is a plan view of the pile driver showing the relationship between a leader, backstays and inclinometers according to the present invention.
FIG. 4 and FIG. 5 are views for explaining a principle of the leader angle control device according to the present invention.
FIG. 6 is a block diagram showing an embodiment of the leader angle control device according to the present invention.
FIGS. 7 and 8 are timing charts for explaining a operation of the embodiment shown in FIG. 6.
FIG. 9 is a block diagram showing an another embodiment of the leader angle control device according to the present invention.
FIGS. 10, 11(a and b) and 12(a and b) are timing charts for explaining an operation of the embodiment shown in FIG. 9.
FIG. 13 is a circuit diagram showing a modification of the MAN-OUTO switching circuit shown in FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description is of the best presently contemplated mode of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention since the scope of the invention is best defined by the appended claims.
In FIG. 3, in the specified positions at the bottom of the leader 5, inclinometers 9 and 10 for detecting the inclination angles of the leader 5 in two directions are disposed, and these two inclinometers 9 and 10 detect leader inclination angles about line l1 and l2 extending from a fulcrum O of the leader inclining to the points S and T of the backstays 6 and 7 being held respectively.
Referring to FIG. 3, when the cylinder 6a is extended or retracted, the leader 5 turns about the line l2 (turning fulcrum is point O), while when the cylinder 7a is extended or retracted the leader 5 thus about the line l1.
Now, if the leader 5 inclines, and the leader center O, which is in the middle of positions 5a and 5b where the backstays are mounted shifts to a point P shown in FIG. 4 departing from the vertical line of the mounting point O of the leader 5, when the cylinder 7a is caused to retract, the leader 5 would turn about the line l1 and as the center O' comes to a point Q, the cylinder 7a would be stopped. Then, cylinder 6a is caused to retract, the leader 5 would turn about the line l2 and as the center O' comes to the vertical line of the mounting point O, the cylinder 6a is stopped. In this manner, the leader 5 can be made vertical. In this case, by controlling both cylinders 7a and 7a concurrently, the center O', can be shifted onto the vertical line of the mounting point O from the point P directly. The displacements corresponding to segment PQ and QO can be obtained by calculation from the outputs of the inclinometers 9 and 10 (shown in FIG. 3). Accordingly, by supplying the oil in the amount corresponding to the displacements PQ and QO to the backstay cylinders 7a and 6a respectively, the center O' can be shifted from the position of point P to a position on the vertical line of the mounting point O directly, thus enabling the leader 5 to become vertical. In addition, by controlling the backstay cylinders 6a and 7a concurrently, the time required for making the leader 5 can be shortened.
Referring now to FIG. 5, L 1 (=SO') and L 2 (=TO') are the lengths of the backstays 6 and 7, and (Xs, Ys, Zs) and (Xt, Yt, Zt) are the coordinates of the points S and T. Further, when L(=OO') is assumed to be the distance between O and O' of the leader 5, the point O' becomes the intersection of three sphericals having the centers O, S, and T and the radii L, L 1 , and L 2 respectively, and the following equations are established.
X.sup.2 +Y.sup.2 +Z.sup.2 =L.sup.2 (1)
(X-Xs).sup.2 +(Y-Ys).sup.2 +(Z-Zs).sup.2 =L.sub.1.sup.2 (2)
(X-Xt).sup.2 +(Y-Yt).sup.2 +(Z-Zt).sup.2 =L.sub.2.sup.2 (3)
where X, Y, Z, L 1 , and L 2 are variables, and Xs, Ys, Zs, Xt, Yt, Zt and L are constants.
When Zs=Zt=0, Xs=Xt, and Ys=-Yt, the above Eqs. (1) to (3) may be written as
X.sup.2 +Y.sup.2 +Z.sup.2 =L.sup.2 (4)
(X-Xs).sup.2 +(Y-Ys).sup.2 +Z.sup.2 =L.sub.1.sup.2 (5)
(X-Xs).sup.2 +(Y-Ys).sup.2 +Z.sup.2 =L.sub.2.sup.2 (6)
When the leader angle δ is small, the value of Z may be taken as substantially equal to the distance L. from the above Eqs. (4) to (6), X, Y, and Z can be expressed as follows: ##EQU1##
In FIG. 5, direction of the inclinometer 9 (shown in FIG. 3) is represented by the unit vector . The end point coordinates of the unit vector is (Xe, Ye, Ze), and the coordinates of the point which the inclinometer 9 is disposed is (nX, nY, nZ), where 0<n<1.
Since vector is orthogonal to vector ¢ and $ respectively (where vector ¢ is 00, and vector $ is OS) the following equations are established:
X(Xe-nX)+Y(Ye-nY)+Z(Ze-nZ)=0 (10)
Xs(Xe-nX)+Ys(Ye-nY)+Zs(Ze-nZ)=0 (11)
On the other hand, the detected angle A by the inclinometer 9 is given by the following equation: ##EQU2##
Eq. (12) can be rewritten using Eqs. (10) and (11) as follows:
From (10)x Ys-(5) x Y ##EQU3##
From (10) x Xs-(11) x X ##EQU4##
Then, Eqs, (13) and (14) are squared, and addition thereof is made as follows: ##EQU5##
By substituting Eq. (15) into Eq. (12), the A can be expressed as follows: ##EQU6##
Then substituting Eqs. (7), (8), and (9) into Eq. (16), and assuming that Zs=0, ##EQU7##
Now, when the lengths of the backstays 6 and 7 are L 10 and L 20 when the leader 5 is vertical and working lengths of backstay cylinders 6a and 7a for setting the leader 5 vertical are ΔL 1 and ΔL 2 , the length of the backstays L 1 , L 2 are generally expressed as
L.sub.1 =L.sub.10 +ΔL.sub.1 (18)
L.sub.2 =L.sub.20 +ΔL.sub.2
and when the upper body 2 (shown in FIGS. 1 and 2) is horizontal or can be approximated as horizontal, following equation is established between the values L 10 and L 20 :
L.sub.10 =L.sub.20 (20)
Accordingly,
L.sub.1.sup.2 ≈L.sub.10.sup.2 +2L.sub.10 ΔL.sub.1 (21)
L.sub.2.sup.2 ≈L.sub.20.sup.2 +2L.sub.20 ΔL.sub.2 (22)
Further, when the leader 5 is vertical, the following equation is established.
Xs.sup.2 +Ys.sup.2 +L.sup.2 =L.sub.10.sup.2 (23)
Accordingly, the following equations is obtained rearranging by substituting Eqs. (21), (22), and (23) into Eq. (17). ##EQU8##
In the same manner, the detected angle β by the inclinometer 10 can be given by the following equation. ##EQU9##
From Eqs. (24) and (25) ΔL 1 and ΔL 2 are given by the following equation. ##EQU10##
In Eq. (26), each element of the first matrix of the right side is constant, and ΔL 1 and ΔL 2 can be determined from the detected angles A and B of the leader inclinometers 9 and 10. Though Eq. (26) is established when the upper body 2 is horizontal, it was found as a result of tests performed by the use of the actual machine that even when the upper body 2 (vehicle body) is more or less inclined, the working lengths ΔL 1 and ΔL 2 of the backstay cylinders can be approximated by Eq. (26) without any effect on the control system of the invention.
FIG. 6 is a block diagram of the leader angle control device of the present invention. The outputs of the inclinometers 9 and 10 are fed to arithmetic circuits 21 and 22 respectively. The arithmetic circuits 21 and 22 perform arithmetic operation according to Eq. (26) based on the output of the inclinometers 9 and 10. calculate values ΔL 1 and ΔL 2 , and output signals ea and eb corresponding thereto. The signals ea and eb are amplified at amplifiers 23 and 24 respectively, and then fed to absolute value circuits 25 and 26, and comparators 27 and 28 respectively. The absolute value circuits 25 and 26 output absolute value signals |ea| and |eb| of the input signals ea and eb, and apply these signals to comparators 31 and 32, respectively. A dead zone setter 29 is for setting a dead zone corresponding to the tolerance of perpendicularity, and outputs a specified dead zone signal ±Δe. On the other hand, a triangular wave generator 30 is for outputting a reference triangular wave signal ET (FIG. 7(a)) of the specified cycle T and output peak level H. The comparator 27, typically a window comparator compares signals eb and ±Δe, when eb<Δe, outputs signal "1", and makes an AND circuit 35 enable, and when eb<-Δe, the comparator 27 makes an AND circuit 36 enable. The comparator 31 compares signals |ea| and ET, and outputs a pulse signal Pa of the pulse width corresponding to the difference between the working length of the cylinder when the leader is vertical and the working length of said cylinder when the leader is presently tilted (FIG. 7(b)) when |ea|>ET, applying it to the AND circuits 33 and 34. The comparator 32 compares signals |eb| and ET, and when |eb|>ET, outputs a pulse signal Pb (FIG. 8(b)) of the pulse width corresponding to the difference, applying the signal to the AND circuits 35 and 36. Driving circuits 38, 37, 39, and 40 are for delivering signals to control the extension and retraction of the back-stay cylinders 6a and 7a. When a pulse signal Pa is fed from the AND circuits 33 and 34, the driving circuits 37 and 38 output a retract/extend signal Sa or Sb of the corresponding back stay cylinder 6a, while the driving circuits 39 and 40 output an extend/retract signal Sc or Sd of the corresponding backstay cylinder 7a when a pulse signal Pb is fed from the AND circuit 35. These signals Sa, Sh, Sc and Sd are applied to each electromagnetic coil C1a, C1b and C2a, C2b of solenoid valves 105 and 106 in the hydraulic circuits of the backstay cylinders 6a and 7a. The oil flow is controlled by controlling the spools of the solenoid valves 105 and 106. Double check valves 107 and 108 open only when the pressure on the solenoid valve side is high, and close when the pressure is low, thus preventing the leader 5 from inclining due to oil leak.
A switch 102 mounted on the control device is a meter indication mode selector. When the switch 102 is positioned to the backstay cylinder mode, the valves ΔL1, and ΔL2 of the cylinder length calculated according to Eq. (26) are indicated on meters 100 and 101 respectively. When the switch 102 is positioned to the inclination angle mode, the inclination angles A and B of the leader are directly indicated. A leader length setting switch 103 is for setting the gains of the amplifiers 23 and 24. A switch 104 is a MAN/AUTO change-over switch.
Now, let's assume that the leader 5 is inclined, and that the center O' is at the point P as shown in FIG. 4. From the arithmetic circuits 21 and 22, signals ea and eb corresponding to the valves ΔL1 and ΔL2 are output respectively. When the relationship between the signal ea and the dead zone setting signal ±Δe and that between the signal eb and the signal ±Δe are ea>Δe and eb>Δe, the AND circuits 33 and 36 become enable. Accordingly pulse signals Pa (FIG. 7(b)) and Pb (FIG. 8(b)) outputted from the comparators 31 and 32 are fed to the driving circuits 37 and 40 through the AND circuits 33 and 36 respectively. The driving circuits 37 and 40 output control signals Sa and Sd corresponding to the input signals Pa and Pb. The backstay cylinders 6a and 7a are retraction-controlled by the quantity of oil corresponding to the pulse widths of the control signals Sa and Sd, and the shift control of the center O' of the leader 5 (FIG. 4) is performed so that said center O' shifts from the position of point P to the vertical line of the point O. When the inclination angle of the leader 5 comes within the dead zone set value ±Δe, the AND circuits 33 and 36 become disable, and the control signals Sa and Sb cease to be output. Accordingly, the backstay cylinders 6a and 7a stop, and the leader 5 is firmly held in that position. Thus the leader 5 is set vertically by driving the two backstay cylinders 6a and 7a concurrently and directly displacing the center O' of the leader 5 from the position of point P to the vertical line of the point O, thereby setting the leader 5 vertical.
Although the preferred embodiment the inclinometers 9 and 10 are disposed so as to intersect orthogonally to the lines l1 and l2 respectively, it is also feasible that those are disposed so as to be in parallel with the X axis and Y axis of FIG. 3 and the values when disposed so as to intersect orthogonally to the lines l1 and l2 are obtained from individual outputs.
In this case, the following relationship exists: ##EQU11## where θX is the output of inclinometer detecting the inclination in parallel with the X axis, θY is the output of inclinometer detecting the inclination in parallel with the Y axis, and ρ is an angle formed between the lines l1 and l2 in FIG. 4. By substituting the above equation (27) into Eq. (26), the relationship between the inclination angle and cylinder length in the case of the inclinometers disposed so as to be in parallel with the axes X Y can be obtained as follows: ##EQU12##
FIG. 9 shows another embodiment of the leader angle control device of the present invention, which is designed so that when the leader is operated manually to a certain extent and then shifted to the automatic range, acceleration to be applied to the leader at the automatic control start-up is kept small by reducing the output of said comparators 31 and 32 temporarily and then gradually increasing the acceleration.
For the above purpose, start control circuits 50 and 60 are provided between the absolute value circuit 25 and the comparator 31 and between the absolute value circuit 26 and the comparator 60 respectively.
The output signal |Va| of absolute value circuit 25 is fed to an arithmetic circuit 55 through a switch 51 and the contact a of an analog switch 52 in the start control circuit 50. The switches 51 and 52 are closed during the automatic control mode of operation. The arithmetic circuit 55 is comprised of a primary or a secondary delay element, typically an integrating circuit, integrates the input signal |Va|, and outputs the signal thus integrated as a signal Vx (FIG. 10), This signal Vx can be expressed by the following equation. ##EQU13## where K 1 is an integration constant. This signal Vx is fed to the one input of a comparator 56 and the contact a of an analog switch 53. The signal |Va| is fed to the other input of the comparator 56 and the contact b of the analog switch 53. The comparator 56 compares the input signal Vx with the signal |Va|, outputs a signal when Vx<|Va| to transfer the analog switches 52 and 53 to the contact a, and when Vx>|Va|, outputs a signal to transfer the switches 52 and 53 to the contact b. Accordingly, when Vx<|Va|, Vx is fed from the analog switch 53 to the comparator 31, and when Vx>|Va|, |Va| is applied from the analog switch 53 to the comparator 31.
The start control circuit 60 is configured similar to the start control circuit 50. An arithmetic circuit 65 integrates the signal |Vb| fed through a switch 61 and and analog switch 62, and outputs the signal thus integrated as a signal Vy. The signal Vy can be expressed as follows: ##EQU14## where K 2 is an integration constant.
A comparator 66 compares the input signal Vy with |Vb|, transfers the analog switches 62 and 63 to the contact a when Vy<|Vb|, and transfers to the contact b when Vy>|Vb|. The signal Vy or |Vb| outputted from the analog switch 63 is fed to a comparator 32. The Switches 51 and 61 becomes ON when an automatic start command signal SA is fed in the automatic control mode. The automatic start command signal SA is output when the operator turns on automatic start switch 104 (FIG. 6).
A comparator 31 compares the signal Vx or |Va| with VT, initially outputs signals of the pulse width corresponding to Vx, and when Vx becomes larger than |Va|, outputs pulse signals Pa1 to Pa6 (FIG. 11b) of the pulse width corresponding to VA, applying those signals to AND circuits 33 and 34. A comparator 32 compares the signal Vy or |Vb| with VT, and outputs similar pulse signals Pb1 to Pb6 (FIG. 12b), applying those signals to AND circuits 35 and 36. The output signals of the AND circuits 33 to 36 are fed to driving circuits 37 to 40 through swtiches 71 to 74 of an MAN-AUTO switching circuit 70 respectively. Each switch 71-74 of the switching circuit 70 becomes ON when the automatic start command signal SA is applied to the switches 51 and 61.
The hydraulic circuits of the back-stay cylinders 6a and 7a are designed so that the manual operation has priority over the automatic control, and the leader 5 can be controlled manually even in the automatic control mode of operation.
As described above, through the control using the signals Vx and Vy in lieu of signals |Va| and |Vb| at the automatic control start-up, acceleration to be applied to the leader 5 can be reduced to a small value, enabling to maintain the stability of the vehicle.
FIG. 13 shows a modification of the MAN-AUTO switching circuit 70 shown in FIG. 9. AND circuits 80 to 83 are used in lieu of the AND circuits 33 to 36, and are designed to become ready condition when an automatic start command signal SA is fed. The circuit configuration can be simplified by such arrangement.
Though in the embodiment shown in FIG. 9 arrangement has been made to provide the switches 51 and 61 in the start control circuits 50 and 60 respectively and to cause the switches 51 and 61 to become ON at the automatic start-up, other alterations and modifications may be made, for example, it is feasible to provide a switch circuit in the input side of arithmetic circuits 21, 22, or to cause the power switch of the control device to be turned on.
Further, though in each embodiment, description has been made regarding the proportional control system, the leader angle control device of the present invention can be applied to other control systems. For example, in the case of the ON-OFF control system, all that is required is to make the system a three level control system providing an additional level between ON and OFF.
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A leader angle control device comprises two inclinometers for measuring inclination of a leader in two directions, an arithmetic unit for calculating the length of two backstays which support the leader based on the detected inclination of the leader and a control unit for controlling backstay cylinder driving oil.
In one embodiment of the leader angle control device, the leader angle is controlled manually to a certain extent before automatic control takes place, whereby the acceleration applied to the leader at the time of shift to automatic control is kept small and then gradually increases, thus enabling smooth control of the inclination of the leader.
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[0001] This application claims the benefit of U.S. Provisional Application No. 60/221,068 filed Jul. 27, 2000, titled “Ballast Discharge System.”
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention:
[0003] The present invention relates in general to ballast discharge equipment for use in depositing ballast material on a rail bed. In particular, the present invention relates to a computer controlled ballast discharge system.
[0004] 2. Description of the Prior Art:
[0005] In the late 1980's, the Burlington Northern Railroad Company initiated the development of a new type of automated ballast railcar. These railcars are operated in unit train groups and have improved the efficiency of ballast unloading by allowing workers to unload a 54-car train with only two employees, and which allowed the ballast discharge operation to be conducted at generally walking speed. The trains could unload in approximately 6 to 9 hours of track time over a period of two days. The automated unit train concept improved the cycle time on the cars (which is the time period from load to reload) dramatically from about 20 days to less than 5 days. Furthermore, it allowed operations to be conducted with fewer employees, which is beneficial from a cost and safety standpoint. By 1997, the successor to the Burlington Northern Railroad Company, the Burlington Northern and Santa Fe Railway Company (“BNSF”) was using automated ballast trains to improve efficiency. This allowed the retiring of old ballast cars from the fleet. There are two types of cars generally used by BNSF. One utilizes an electrical system in which the discharge gates are radio controlled, and the other utilizes a hydraulic system in which the discharge gates are hydraulically controlled. On cars with hydraulic gates, some of the gates may be radio controlled and some may be manually controlled with actuating handles on the side of the car.
[0006] Of course, it is always desirable to operate at higher rates and with fewer personnel. The present invention is directed to an improvement to the prior art automated ballast discharge railcars.
SUMMARY OF THE INVENTION
[0007] There is a need for an improved railroad ballast discharge system that utilizes global position systems (“GPS”).
[0008] It is one objective of the present invention to utilize GPS in combination with an automatic ballast discharge railcar in order to further improve ballast discharge operations by increasing the speed of operations, by reducing the number of personnel required, and by providing for relatively well controlled predictable depositions of ballast.
[0009] It is another objective of the present invention to provide an improved ballast discharge system which allows at least one controller and at least one GPS receiver to receive global position data from global position satellites, to read the global position data, to compare the global position data to global position information recorded in program memory, and to open and close discharge gates of a plurality of ballast railcars in a pre-programmed and pre-determined manner in order to deposit ballasts at pre-selected portions of the rail line and to not deposit ballast in other pre-selected portions of the rail line.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use and further objectives and advantages thereof, will best be understood by reference to the following detailed description of the preferred embodiment when read in conjunction with the accompanying drawings, wherein:
[0011] [0011]FIG. 1A is a pictorial representation of an automated ballast rail car according to the present invention;
[0012] [0012]FIG. 1B is an enlarged pictorial representation of one of the ballast discharge gates of the automated ballast railcar of FIG. 1A;
[0013] [0013]FIG. 2 is a block diagram representation of the present invention which utilizes a GPS receiver to provide GPS derived location data to a central processing unit;
[0014] [0014]FIG. 3A is a schematic representation of a section of rail line;
[0015] [0015]FIG. 3B is a detailed view of the section of rail line of FIG. 3A, showing preselected portions of the rail line in which the ballast is to be deposited or not deposited;
[0016] [0016]FIG. 4 if a flow-chart representation of the preferred process of determining and recording location and ballast requirements for a portion of rail line;
[0017] [0017]FIG. 5 is a flow-chart representation of the operation of the computer program to selectively discharge ballast in accordance with pre-selected and pre-programmed location and discharge data;
[0018] [0018]FIG. 6 is a pictorial representation of a portion of a ballast train according to the present invention; and
[0019] [0019]FIG. 7 is a tabular representation of operation depicted in FIG. 3B.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring to FIGS. 1A and 1B in the drawings, pictorial representations of a cargo discharge railcar 11 according to the present invention are illustrated. Railcar 11 includes a generally rectangular base structure 17 , walls 19 coupled to base structure 17 , and hoppers 21 coupled to base structure 17 . A plurality of rail wheel assemblies 23 are coupled to the underneath side of base structure 17 . In the preferred embodiment, the cargo is railroad ballast. Discharge gates 13 may be selectively actuated and moved between an open condition and a closed condition. When in the closed condition, discharge gates 13 prevent the discharge of ballast (not shown) carried within railcar 11 . When in the open condition, discharge gates 13 allow the ballast to be discharged at a pre-selected flow rate through discharge gates 13 and onto a road bed 15 . Discharge gates 13 may actuated by electrical means, hydraulic means, a combination of electrical and hydraulic means, or other means for actuating similar discharge gates.
[0021] Referring now to FIG. 2 in the drawings, a block diagram representation of the present invention is illustrated. As is shown, a plurality of GPS transmitters, including GPS transmitters 101 and 103 are provided in orbit above the Earth and may be utilized in a conventional manner to determine a location in terms of latitude and longitude by the interaction between at least one GPS receiver and the one or more GPS transmitters 101 and 103 . As is shown, at least one GPS receiver 105 is carried by railcar 11 . GPS receiver 105 may be located in one of the ballast railcars or it may be located in some other location, such as the locomotive. GPS receiver 105 communicates GPS data to a central processing unit (CPU) 107 with which is associated conventional supporting electronics, such as RAM memory 109 and ROM memory 111 . RAM memory 109 and ROM memory 111 may be utilized to record program instructions which may be executed by central processing unit 107 in order to generate signals for controlling the discharge of ballast from a series or train of cargo discharge railcars 11 . Typically, a relatively large number of ballast railcars, such as fifty railcars, are utilized to deposit ballast where needed to build up road bed 15 . The requirements of a particular portion of a rail line may vary. A typical ballast discharge operation will require the discharge of from one hundred to six hundred tons of ballast per mile with railcars generally containing one hundred tons of ballast per car. The tonnage that is deposited will depend upon the speed of railcars 11 , the number of railcars 11 used, the number of discharge gates 13 in the open condition, and the size of discharge gates 13 , which determines the flow rate of the ballast through discharge gate 13 . Typically, a ballast railcar 11 carries four discharge gates on the undercarriage. Relatively simple mathematical calculations can be done to determine the number of gates which are required to be in the open condition to discharge a predetermined amount of ballast over a predetermined portion of a rail line at a given velocity. Typically, once the discharge operations begin, a number of cars are unloaded continuously through the discharge gates. For example, it is not uncommon for five cars worth of ballast to be emptied out over one mile of a rail line.
[0022] It is important to note that there may be sections of railroad in which little or no discharge is required. For example, there may be sections with turnouts or switches, road crossings, bridges, and/or tunnels which may not require any additional ballast. Accordingly, it is one objective of the present invention to allow for the selective opening and closing of gates in accordance with preprogrammed GPS location data and preprogrammed discharge data in order to deposit the appropriate amount of ballast in only the appropriate locations, and to prevent the discharge of ballast in predetermined locations which do not require additional ballast.
[0023] At present it is conventional to merely open or close discharge gates 13 . However, it is possible to utilize the present invention to open and close discharge gates 13 in pre-selected amounts in order to better control or “throttle” the rate of discharge of ballast at particular portions of a rail line. At present, the ballast material is relatively uniform in both size and weight so it is practical to assume that each gate will discharge a comparable amount of ballast. It is typical to have each ballast railcar 11 carry as much as 100 tons of ballast rock.
[0024] Returning now to FIG. 2 in the drawings, as is shown, CPU 107 controls and maintains control valves 113 , 115 , and 117 . Control valves 113 , 115 , and 117 operate to switch discharge gates 13 from the open condition to the closed condition, and vice versa. It should be understood that control valves 113 , 115 , and 117 may be either electrical or hydraulic control valves, or any other suitable control valve. Additionally, the duration of the open and/or closed condition of each gate may be determined by a clock 110 for the speed data received at input 112 , which represents the current speed of the train in units of miles per hour, or any other appropriate measure of velocity. Accordingly, control valves 113 , 115 , and 117 may be opened and closed in accordance with preprogrammed instructions. In other words, the GPS locations at which each discharge gate 13 is opened and closed may be preprogrammed. In this manner, both location and amount of the discharge may be controlled by CPU 107 .
[0025] Referring now to FIGS. 3A and 3B in the drawings, the operation of discharging the ballast on a particular rail line is depicted schematically. As is shown, a rail line comprising sections 125 , 127 , and 129 extends between Station A represented by reference numeral 121 , and Station B represented by reference numeral 123 . In the operation depicted in FIG. 3A, section 125 of the rail line does not require any additional ballast, nor does section 129 . However, section 127 of rail between location L 1 and location LN does require the discharge of a particular amount of ballast. FIG. 3B is a detailed schematic depiction of the Section 127 . As is shown, Section 127 begins at location L 1 and ends at location LN. Location L 1 is determined by GPS data in terms of latitude and longitude. Likewise, location LN is determined by a particular latitude and a longitude. As is shown, there are several rail segments, 137 , 139 , 141 , 143 which require additional ballasts in predetermined amounts. For example, segment 137 requires an amount “X” of ballast; segment 139 requires an amount “Y” of ballast; segment 141 requires an amount “X” of ballast; and segment 143 requires an amount “A” of ballast. Each of these ballast amounts may be set forth in tons of ballast per linear mile. For each rate of travel, the operator will know the amount of discharge possible for each ballast rail car 11 in terms of ballast discharge per discharge gate 13 per unit of time. With these variables, the amount of ballast that can be deposited can be determined with some precision.
[0026] Continuing with reference to FIG. 3B, segment 137 is located between location L 1 and location L 2 . Location L 1 is determined by latitude LAT 1 and longitude LON 1 . Location L 2 is determined by latitude LAT 2 and longitude LON 2 . Segment 139 is located between location L 3 and location L 4 . Location L 3 is determined by latitude LAT 3 and longitude LON 3 . Location L 4 is determined by latitude LAT 4 and longitude LON 4 . Location LN is determined by latitude LATN and longitude LONN. Segment 141 is located between location L 5 and location L 6 . Location L 5 is determined by latitude LAT 5 and longitude LON 5 . Location L 6 is determined by latitude LAT 6 and longitude LON 6 . Segment 143 is located between location L 7 and location LN. Location L 7 is determined by latitude LAT 7 and longitude LON 7 . Location LN is determined by latitude LATN and longitude LONN.
[0027] A rail tunnel 131 is located between location L and location L 3 . In the example of FIG. 3B, there is no need to deposit a ballast in rail tunnel 131 located between location L 2 and location L 3 . The same is true for a rail crossing 133 located between location L 4 and location L 5 , and turnout 135 located between location L 6 and location L 7 . Each of these locations L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7 , and LN is determined by corresponding GPS data in terms of longitude and latitude.
[0028] Referring now to FIG. 4 in the drawings, a flow chart overview of one preferred implementation of the present invention is provided. The process begins at block 201 . In step 203 , a survey of a section of a rail line is performed, either by railroad personnel, or with the use of GPS survey information from other railroad track maintenance applications. With reference to FIG. 3A, the survey would include rail segment 127 which is located between location L 1 and location LN. Next, in accordance with step 205 , the sections which need additional ballast are identified, either by railroad personnel, or with the use of GPS survey information from other railroad track maintenance applications. With reference to the example of FIG. 3B, rail tunnel 131 , railroad crossing 133 , and turnout 135 do not require additional ballast. Next, in accordance with step 207 , the GPS system data for each start location is recorded. Likewise, in accordance with step 209 , the GPS data for each stop location is recorded. With reference to the example of FIG. 3B, the start locations are location L 1 , location L 3 , location L 5 , and location L 7 . Furthermore, the stop locations are location L 2 , location L 4 , location L 6 , and location LN. In accordance with step 211 , the ballast requirements for each segment are recorded. Again, with reference to the example of FIG. 3B, segment 137 which is between locations L 1 and L 2 requires a ballast in the amount of “X.” Segment 139 which is located between location L 3 and location L 4 requires ballast in an amount of “Y.” Segment 141 which is located between location L 5 and location L 6 requires ballast in an amount of “Z.” Segment 143 which is located between location L 7 and location LN requires ballast in the amount of “A.”
[0029] Continuing with reference to the flow chart of FIG. 4, in accordance with steps 213 and 215 , CPU 107 has been programmed to calculate and record gating requirements based upon various amounts of ballast for each location and at varying speeds of unloading. Then, in accordance with step 217 , programmed CPU 107 associates the GPS location data and the gating requirements data. Essentially, a data base is built which maps out a plan for depositing ballast along predetermined sections of rail which need the ballast. The process ends at step 219 .
[0030] Referring now to FIG. 5 in the drawings, a flow chart representation of the preferred implementation of the present invention is illustrated. The process begins at block 251 and continues at block 253 , wherein, the CPU 107 of FIG. 2 loads the GPS data and associated ballast amounts and gate requirements data into RAM memory 109 and ROM memory 111 . Then, in accordance with step 255 , CPU 107 reads the GPS signals from GPS receiver 105 . Then, in accordance with step 257 , CPU 107 compares the GPS signal to the GPS signal maintained in the data base. In accordance with blocks 259 and 263 , CPU 107 determines through this comparison whether discharge gates 13 are required to be open or closed if there is a match. If there is a match for an open gate condition, CPU 107 will then signal an appropriate control valve 113 , 115 , or 117 to open corresponding discharge gates 13 in accordance with step 261 . However, if the comparison of the GPS signal with the GPS data in the data base results in a match for a closed gate condition, CPU 107 will then signal an appropriate control valve 113 , 115 , or 117 to close corresponding discharge gates 13 in accordance with step 265 . For the example of FIG. 3B, this process is iteratively repeated until section 127 of rail line is traveled in its entirety. In this manner, pre-selected discharge gates 13 are opened and closed at predetermined locations in order to deposit a predetermined amount of ballast to build up the road bed to a desired level.
[0031] Referring now to FIG. 6 in the drawings, a pictorial representation of a portion of a ballast train according to the present invention is illustrated. In a typical operation, five ballast rail cars C 1 , C 2 , C 3 , C 4 , and C 5 may be simultaneously discharging ballast at a predetermined rate over a pre-selected segment of rail line. The system and CPU 107 of the present invention receive and compare GPS data to determine when to open and close discharge gates 13 so as to discharge the predetermined amounts of ballast at the predetermined segments of the rail line. When cars C 1 , C 2 , C 3 , C 4 , and C 5 are empty, CPU 107 cause other cars to begin discharging ballast.
[0032] Referring now to FIG. 7 in the drawings, a tabular representation of the operation depicted in FIG. 3B is illustrated. A table 100 shows the correlation between the position intervals of the ballast train relative to locations L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7 , and LN; the amount of ballast discharged during these intervals; and whether discharge gates 13 are in the open condition or the closed condition.
[0033] It should be understood that the present invention may be used on ballast discharge railcars of original manufacture, or may be used in retrofit applications on existing ballast discharge railcars. In retrofit applications, the existing control systems for opening and closing the discharge gates of the existing ballast discharge railcars are replaced by the control systems of the present invention, as necessary to utilize the GPS data.
[0034] Although the present invention has been described with reference to the preferred embodiment of discharging ballast on railroad beds, it should be understood that the present invention may be utilized in any railroad application in which it is desirable to discharge a selected amount of cargo at selected points or over selected distances.
[0035] It should be apparent from the foregoing that an invention having significant advantages has been provided. While the invention is shown in only one of its forms, it is not just limited but is susceptible to various changes and modifications without departing from the spirit thereof. Various modifications of the disclosed embodiments as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that any appended claims will cover any such modifications or embodiments that fall within the scope of the invention.
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A cargo discharge railcar for comprising a generally rectangular base structure, a plurality of walls coupled to the base structure defining an enclosure for carrying cargo, a hopper portion coupled to the base structure, a discharge gate coupled to the hopper portion, a control system coupled to the discharge gate for opening and closing the discharge gate, a central processing unit for controlling the control system, and a global positioning system receiver electrically coupled to the central processing unit for receiving longitude and latitude data from a global positioning system transmitter orbiting the Earth. The discharge gate is adapted to be selectively opened and closed based in part upon the longitude and latitude of the cargo discharge railcar.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority of Korean Patent Application Number 10-2013-0128677 filed on Oct. 28, 2013, the entire contents of which application are incorporated herein for all purposes by this reference.
BACKGROUND OF INVENTION
1. Field of Invention
The present invention relates to a double clutch transmission of a vehicle that can achieve seven forward speeds without increasing a length of the transmission.
2. Description of Related Art
A double clutch transmission of a vehicle includes two clutch devices, two input shafts and two output shafts. The double clutch transmission (DCT) selectively transmits torque of an engine to two input shafts through two clutch devices, converts the torque into target torque using a plurality of input gears disposed on the two input shafts and a plurality of speed gears engaged respectively to the input gears and disposed on the two output shafts and outputs the target torque.
Such the DCT is used to realize a compact transmission having more than five forward speeds. Since two clutches and synchronizing devices are controlled by a controller according to the DCT, manual shift maneuver is unnecessary for controlling the DCT. Therefore, the DCT is one type of automated manual transmissions (AMT).
The DCTs have different layouts according to vehicle manufacturers. The DCT realizing six forward speeds or seven forward speeds is being developed to enhance fuel consumption and efficiently use engine driving torque.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
SUMMARY OF INVENTION
The present invention has been made in an effort to provide a double clutch transmission of a vehicle having advantages of being mounted in a vehicle without layout change of an engine compartment and curtailing cost by minimizing a length of the transmission and achieve seven forward speeds.
A double clutch transmission of a vehicle according to various aspects of the present invention may include: a variable connecting device including first and second clutches and selectively transmitting power of a power source; an input device including a first input shaft selectively receiving the power of the power source through the first clutch, and a second input shaft disposed at a radial exterior of the first input shaft without rotational interference therebetween and selectively receiving the power of the power source through the second clutch; a speed output device including a first speed output unit disposed in parallel with the first and second input shafts, changing the power transmitted from the first input shaft or the second input shaft into four forward speeds and outputting the four forward speeds, and a second speed output unit disposed in parallel with the first and second input shafts, changing the power transmitted from the first input shaft or the second input shaft into two forward speeds and outputting the two forward speeds; a first transfer gear assembly disposed in the second speed output unit, reducing rotational speed of the power transmitted from the second input shaft and outputting the reduced rotational speed; and a second transfer gear assembly disposed in parallel with the second speed output unit, changing the rotational speed transmitted from the first transfer gear assembly selectively into one forward speed or one reverse speed and transmitting the one forward speed or the one reverse speed to the second speed output unit.
The first input shaft may be provided with first, second and third input gears sequentially disposed thereon, wherein the first input gear is an input gear for achieving a fourth forward speed, the second input gear is an input gear for achieving a second forward speed and the third input gear is an input gear for achieving a sixth forward speed.
The second input shaft may be provided with fourth and fifth input gears sequentially disposed thereon, wherein the fourth input gear is an input gear for achieving a first forward speed, a third forward speed and the reverse speed, and the fifth input gear is an input gear for achieving a fourth forward speed.
The first speed output unit may include: a first output shaft disposed in parallel with and away from the first and second input shafts; third, fourth, sixth and seventh speed gears disposed on the first output shaft; a first synchronizer selectively connecting the third forward speed gear or the seventh forward speed gear to the first output shaft; a second synchronizer selectively connecting the fourth forward speed gear or the sixth forward speed gear to the first output shaft; and a first output gear fixedly disposed on the first output shaft.
The third forward speed gear may be engaged with the fourth input gear and the seventh forward speed gear may be engaged with the fifth input gear.
The fourth forward speed gear may be engaged with the first input gear and the sixth forward speed gear may be engaged with the third input gear.
The second speed output unit may include: a second output shaft disposed in parallel with and away from the first and second input shafts; second and fifth speed gears disposed on the second output shaft; a third synchronizer selectively connecting the second forward speed gear or the fifth forward speed gear to the second output shaft; and a second output gear fixedly disposed on the second output shaft.
The second forward speed gear may be engaged with the second input gear and the fifth forward speed gear may be engaged with the fifth input gear.
The first transfer gear assembly may include: a first transfer gear shaft disposed at a radial exterior of the second output shaft of the second speed output unit without rotational interference therebetween; a first transfer input gear formed on an end portion of the first transfer gear shaft and engaged with the fourth input gear of the second input shaft; and a first transfer output gear formed on the other end portion of the first transfer gear shaft.
The second transfer gear assembly may include: a second transfer gear shaft disposed in parallel with and away from the first and second input shafts; a rotating direction changing device disposed on the second transfer gear shaft and adapted to receive the power from the second input shaft through a second transfer input gear and to change a rotating direction of the power; a fourth synchronizer controlling the rotating direction changing device to change the rotating direction; and a second transfer output gear transmitting power from the second transfer gear shaft to the second speed output device.
The double clutch transmission may further include a parking brake gear fixedly disposed at the second transfer gear shaft.
The rotating direction changing device may include: an idle shaft disposed at a radial exterior of the second transfer gear shaft without rotational interference therebetween; a second transfer input gear fixedly disposed on a side portion of the idle shaft and receiving the power from the first transfer gear assembly; a first sun gear fixedly disposed on the other side portion of the idle shaft; a second sun gear fixedly disposed on the second transfer gear shaft; and a carrier disposed at a radial exterior of the second transfer gear shaft without rotational interference therebetween and rotatably supporting a first pinion engaged with the first sun gear and a second pinion engaged with the first pinion and the second sun gear.
The fourth synchronizer may include: a hub gear fixedly connected to the carrier; a sleeve engaged with an external circumference of the hub gear and being movable in an axial direction; a first forward speed clutch gear fixedly disposed on the second transfer gear shaft at a side of the hub gear and selectively engaged with the sleeve; and a fixed clutch gear fixedly connected to a transmission housing at the other side of the hub gear and selectively engaged with the sleeve.
A double clutch transmission of a vehicle according to various other aspects of the present invention may include: a variable connecting device including first and second clutches and selectively transmitting power of a power source; an input device including a first input shaft provided with first, second and third input gears fixedly disposed on an external circumference thereof and selectively receiving the power of the power source through the first clutch, and a second input shaft provided with fourth and fifth input gears fixedly disposed on an external circumference thereof, disposed at a radial exterior of the first input shaft without rotational interference therebetween and selectively receiving the power of the power source through the second clutch; a first speed output unit including a first output shaft disposed in parallel with the first and second input shafts and provided with a first output gear fixedly disposed on an external circumference thereof, third, fourth, sixth and seventh speed gears disposed on the first output shaft, a first synchronizer selectively connecting the third forward speed gear or the seventh forward speed gear to the first output shaft and a second synchronizer selectively connecting the fourth forward speed gear or the sixth forward speed gear to the first output shaft; a second speed output unit including a second output shaft disposed in parallel with the first and second input shafts and provided with a second output gear fixedly disposed on an external circumference thereof, second and fifth speed gears disposed on the second output shaft and a third synchronizer selectively connecting the second forward speed gear or the fifth forward speed gear to the second output shaft; a first transfer gear assembly disposed in the second speed output unit, changing a rotational speed of the power transmitted from the second input shaft and outputting the changed rotational speed; and a second transfer gear assembly disposed in parallel with the second speed output unit, changing the rotational speed transmitted from the first transfer gear assembly selectively into one forward speed or one reverse speed and transmitting the one forward speed or the one reverse speed to the second speed output unit.
The third forward speed gear may be engaged with the fourth input gear and the seventh forward speed gear may be engaged with the fifth input gear.
The fourth forward speed gear may be engaged with the first input gear and the sixth forward speed gear may be engaged with the third input gear.
The second forward speed gear may be engaged with the second input gear and the fifth forward speed gear may be engaged with the fifth input gear.
The first transfer gear assembly may include: a first transfer gear shaft disposed at a radial exterior of the second output shaft of the second speed output unit without rotational interference therebetween; a first transfer input gear formed on an end portion of the first transfer gear shaft and engaged with the fourth input gear of the second input shaft; and a first transfer output gear formed on the other end portion of the first transfer gear shaft.
The second transfer gear assembly may include: a second transfer gear shaft disposed in parallel with and away from the first and second input shafts; a rotating direction changing device disposed on the second transfer gear shaft and adapted to receive the power from the second input shaft through a second transfer input gear and to change a rotating direction of the power; a fourth synchronizer controlling the rotating direction changing device to change the rotating direction; and a second transfer output gear transmitting power from the second transfer gear shaft to the second speed output device.
The rotating direction changing device may include: an idle shaft disposed at a radial exterior of the second transfer gear shaft without rotational interference therebetween; a second transfer input gear fixedly disposed on a side portion of the idle shaft and receiving the power from the first transfer gear assembly; a first sun gear fixedly disposed on the other side portion of the idle shaft; a second sun gear fixedly disposed on the second transfer gear shaft; and a carrier disposed at a radial exterior of the second transfer gear shaft without rotational interference therebetween and rotatably supporting a first pinion engaged with the first sun gear and a second pinion engaged with the first pinion and the second sun gear.
The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an exemplary double clutch transmission according to the present invention.
FIG. 2 is schematic diagram illustrating arrangement of shafts used in an exemplary double clutch transmission according to the present invention.
FIG. 3 is a schematic diagram illustrating flow of power at the first forward speed in an exemplary double clutch transmission according to the present invention.
FIG. 4 is a schematic diagram illustrating flow of power at a reverse speed in an exemplary double clutch transmission according to the present invention.
DETAILED DESCRIPTION
Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
Description of components that are not necessary for explaining the present exemplary embodiment will be omitted, and the same constituent elements are denoted by the same reference numerals in this specification. In the detailed description, ordinal numbers are used for distinguishing constituent elements having the same terms, and have no specific meanings.
FIG. 1 is a schematic diagram of a double clutch transmission according to various embodiments of the present invention. Referring to FIG. 1 , a double clutch transmission according to various embodiments of the present invention includes a variable connecting device provided with first and second clutches CL 1 and CL 2 , an input device provided with first and second input shafts IS 1 and IS 2 , a speed output device provided with first and second speed output units OUT 1 and OUT 2 converting rotation speed of power input through the input device according to each shift-speed and outputting the converted power, a first transfer gear assembly TGA 1 and a second transfer gear assembly TGA 2 .
The first and second clutches CL 1 and CL 2 included in the variable connecting device selectively transmits torque of an engine ENG to the first and second input shafts IS 1 and IS 2 . The first clutch C 1 selectively transmits the torque of the engine ENG to the first input shaft IS 1 and the second clutch CL 2 selectively transmits the torque of the engine ENG to the second input shaft IS 2 .
The input device includes a first input shaft IS 1 selectively connected to the engine ENG through the first clutch CL 1 and a second input shaft IS 2 selectively connected to the engine ENG through the second clutch CL 2 . The second input shaft IS 2 is a hollow shaft, and the first input shaft IS 1 is inserted in the second input shaft IS 2 without rotational interference with the second input shaft IS 2 .
First, second and third input gears G 1 , G 2 , and G 3 are disposed at an exterior circumference of the first input shaft IS 1 with predetermined distances. The first, second and third input gears G 1 , G 2 , and G 3 are positioned at a rear portion of the first input shaft IS 1 penetrating the second input shaft IS 2 and are disposed in a sequence of the first, second and third input gears G 1 , G 2 , and G 3 .
Fourth and fifth input gears G 4 and G 5 are disposed on the second input shaft IS 2 with a predetermined distance. The fourth input gear G 4 is disposed at a front portion of the second input shaft IS 2 and the fifth input gear G 5 is disposed at a rear portion of the second input shaft IS 2 .
Therefore, the first, second and third input gears G 1 , G 2 and G 3 as well as the first input shaft IS 1 are rotated if the first clutch CL 1 is operated, and the fourth and fifth input gears G 4 and G 5 as well as the second input shaft IS 2 are rotated if the second clutch CL 2 is operated.
The first, second, third, fourth and fifth input gears G 1 , G 2 , G 3 , G 4 and G 5 are input gears operating at each shift-speed and teeth numbers thereof are determined according to target gear ratio at each shift-speed.
The speed output device that changes rotation speed of the torque input through the input device and outputs the changed speed includes the first and second speed output units OUT 1 and OUT 2 disposed in parallel or substantially in parallel with the first and second input shafts IS 1 and IS 2 .
The first speed output unit OUT 1 includes a first output shaft OS 1 disposed in parallel with and away from the first and second input shafts IS 1 and IS 2 , third, fourth, sixth and seventh forward speed gears D 3 , D 4 , D 6 , and D 7 , a first synchronizer SL 1 selectively connecting the third forward speed gear D 3 or the seventh forward speed gear D 7 to the first output shaft OS 1 , a second synchronizer SL 2 selectively connecting the fourth forward speed gear D 4 or the sixth forward speed gear D 6 to the first output shaft OS 1 and a first output gear OG 1 .
The third forward speed gear D 3 is engaged with the fourth input gear G 4 and the seventh forward speed gear D 7 is engaged with the fifth input gear G 5 .
In addition, the first synchronizer SL 1 includes a first hub gear H 1 fixedly disposed on the first output shaft OS 1 , a first sleeve SLE 1 meshed at an external circumference of the first hub gear H 1 and being slidable in an axial direction, a third forward speed clutch gear CG 3 integrally formed with the third forward speed gear D 3 and selectively engaged with the first sleeve SLE 1 and a seventh forward speed clutch gear CG 7 integrally formed with the seventh forward speed gear D 7 and selectively engaged with the first sleeve SLE 1 .
If the first sleeve SLE 1 is engaged with the third forward speed clutch gear CG 3 , rotation speed of the engine ENG is changed according to gear ratios of the fourth input gear G 4 and the third forward speed gear D 3 and the changed rotation speed is output through the first output shaft OS 1 and the first output gear OG 1 . Therefore, a third forward speed is achieved. In addition, if the first sleeve SLE 1 is engaged with the seventh forward speed clutch gear CG 7 , the rotation speed of the engine ENG is changed according to gear ratios of the fifth input gear G 5 and the seventh forward speed gear D 7 and the changed rotation speed is output through the first output shaft OS 1 and the first output gear OG 1 . Therefore, a seventh forward speed is achieved.
The fourth forward speed gear D 4 is engaged with the first input gear G 1 and the sixth forward speed gear D 6 is engaged with the third input gear G 3 .
In addition, the second synchronizer SL 2 includes a second hub gear H 2 fixedly disposed on the first output shaft OS 1 , a second sleeve SLE 2 meshed at an external circumference of the second hub gear H 2 and being slidable in the axial direction, a fourth forward speed clutch gear CG 4 integrally formed with the fourth forward speed gear D 4 and selectively engaged with the second sleeve SLE 2 and a sixth forward speed clutch gear CG 6 integrally formed with the sixth forward speed gear D 6 and selectively engaged with the second sleeve SLE 2 .
If the second sleeve SLE 2 is engaged with the fourth forward speed clutch gear CG 4 , the rotation speed of the engine ENG is changed according to gear ratios of the first input gear G 1 and the fourth forward speed gear D 4 and the changed rotation speed is output through the first output shaft OS 1 and the first output gear OG 1 . Therefore, a fourth forward speed is achieved. In addition, if the second sleeve SLE 2 is engaged with the sixth forward speed clutch gear CG 6 , the rotation speed of the engine ENG is changed according to gear ratios of the third input gear G 3 and the sixth forward speed gear D 6 and the changed rotation speed is output through the first output shaft OS 1 and the first output gear OG 1 . Therefore, a sixth forward speed is achieved.
The power converted by the first speed output unit OUT 1 is transmitted to the first output gear OG 1 mounted on a front end portion of the first output shaft OS 1 to a final reduction gear FD of a differential apparatus DIFF.
The second speed output unit OUT 2 includes an output shaft OS 2 disposed in parallel with and away from the first and second input shafts IS 1 and IS 2 , the first transfer gear assembly TGA 1 , second and fifth forward speed gears D 2 and D 5 , a third synchronizer SL 3 selectively connecting the second forward speed gear D 2 or the fifth forward speed gear D 5 to the second output shaft OS 2 and a second output gear OG 2 .
The first transfer gear assembly TGA 1 includes a first transfer gear shaft TS 1 being a hollow shaft and disposed at a radial exterior of the second output shaft OS 2 , a first transfer input gear TI 1 disposed at a side portion of the first transfer gear shaft TS 1 and engaged with the fourth input gear G 4 and a first transfer output gear TO 1 disposed at the other side portion of the first transfer gear shaft TS 1 .
In addition, since a diameter of the first transfer input gear TI 1 is larger than that of the first transfer output gear TO 2 , the rotation speed input to the first transfer input gear TI 1 is reduced through the first transfer output gear TO 2 .
In addition, the second forward speed gear D 2 is engaged with the second input gear G 2 and the fifth forward speed gear D 5 is engaged with the fifth input gear G 5 .
The third synchronizer SL 3 includes a third hub gear H 3 fixedly disposed on the second output shaft OS 2 , a third sleeve SLE 3 engaged at an external circumference of the third hub gear H 3 and being slidable in the axial direction, a second forward speed clutch gear CG 2 integrally formed with the second forward speed gear D 2 and selectively engaged with the third sleeve SLE 3 and a fifth forward speed clutch gear CG 5 integrally formed with the fifth forward speed gear D 5 and selectively engaged with the third sleeve SLE 3 .
If the third sleeve SLE 3 is engaged with the second forward speed clutch gear CG 2 , the rotation speed of the engine ENG is changed according to gear ratios of the second input gear G 2 and the second forward speed gear D 2 and the changed rotation speed is output through the second output shaft IS 2 and the second output gear OG 2 . Therefore, a third forward speed is achieved. In addition, if the third sleeve SLE 3 is engaged with the fifth forward speed clutch gear CG 5 , the rotation speed of the engine ENG is changed according to gear ratios of the fifth input gear G 5 and the fifth forward speed gear D 5 and the changed rotation speed is output through the second output shaft OS 2 and the second output gear OG 2 . Therefore, a fifth forward speed is achieved.
The power converted by the second speed output unit OUT 2 is transmitted to the final reduction gear FD of the differential apparatus DIFF through the second output gear OG 2 mounted at a front portion of the second output shaft OS 2 .
Meanwhile, the second transfer gear assembly TGA 2 changes direction and rotation speed of the power transmitted from the first transfer gear assembly TGA 1 and outputs the changed power to the second output shaft OS 2 .
For this purpose, the second transfer gear assembly TGA 2 includes a second transfer gear shaft TS 2 disposed in parallel with and away from the first and second input shafts IS 1 and IS 2 , a second transfer input gear TI 2 , a rotating direction changing device RC, a fourth synchronizer SL 4 , a second transfer output gear TO 2 and a parking brake gear PG.
The rotating direction changing device RC is integrally formed with an idle shaft IDS being a hollow shaft and disposed on a radial exterior of the second transfer gear shaft TS 2 without rotational interference therebetween. The rotating direction changing device RC includes a second transfer input gear TI 2 formed at a side portion of the idle shaft IDS and engaged with the first transfer output gear TO 1 , a first sun gear S 1 integrally formed at the other side portion of the idle shaft IDS, a second sun gear S 2 integrally formed with the second transfer gear shaft TS 2 and a carrier PC rotatably supporting a first pinion P 1 disposed at a radial exterior of the second transfer gear shaft TS 2 without rotational interference therebetween and engaged with the first sun gear S 1 and a second pinion P 2 engaged with the first pinion P 1 and the second sun gear S 2 .
That is, the first sun gear S 1 engaged with the first pinion P 1 is directly connected to the second transfer input gear TI 2 so as to be operated as an input element, a second sun gear S 2 is operated as an output element that outputs a negative rotation speed at a reverse speed, and the carrier PC is operated as an output element at a first forward speed and is operated as a fixed element at the reverse speed.
Meanwhile, the fourth synchronizer SL 4 includes a fourth hub gear H 4 fixedly disposed on the carrier PC, a fourth sleeve SLE 4 engaged at an external circumference of the fourth hub gear H 4 and being slidable in the axial direction, a first forward speed clutch gear CG 1 integrally formed with the second transfer gear shaft TS 2 at a side of the fourth hub gear H 4 and selectively engaged with the fourth sleeve SLE 4 and a fixed clutch gear FC connected to a transmission housing H at the other side of the fourth hub gear H 4 and selectively engaged with the fourth sleeve SLE 4 .
If the fourth sleeve SLE 4 is engaged with the first forward speed clutch gear CG 1 , the power transmitted from the carrier PC is output through the second transfer gear shaft TS 2 and the second transfer output gear TO 2 . If the fourth sleeve SLE 4 is engaged with the fixed clutch gear FC, the negative rotation speed transmitted from the second sun gear S 2 is output through the second transfer gear shaft TS 2 and the second transfer output gear TO 2 .
Sleeves SLE 1 , SLE 2 , SLE 3 and SLE 4 applied respectively to the first, second, third and fourth synchronizers SL 1 , SL 2 , SL 3 and SL 4 are operated by additional actuators and the actuators are controlled by a transmission control unit.
The actuator may be operated by an electric motor or a hydraulic control system but is not limited to this.
FIG. 2 is schematic diagram illustrating arrangement of shafts used in a double clutch transmission according to an exemplary embodiment of the present invention.
Referring to FIG. 2 , the first and second input shafts IS 1 and IS 2 , the first and second output shafts OS 1 and OS 2 , the second transfer gear shaft TS 2 and the differential apparatus DIFF are disposed away from each other, and the first and second output gears OG 1 and OG 2 fixedly disposed respectively on the first and second output shafts OS 1 and OS 2 are connected to the final reduction gear FD of the differential apparatus DIFF.
FIG. 3 is a schematic diagram illustrating flow of power at the first forward speed in a double clutch transmission according to an exemplary embodiment of the present invention.
Odd-numbered speeds and even-numbered speeds are alternately realized at the second forward speed, the third forward speed, the fourth forward speed, the fifth forward speed, the sixth forward speed and the seventh forward speed other than the reverse speed and the first forward speed in the double clutch transmission according to some embodiments of the present invention. Alternate realization of the odd-numbered speeds and the even-numbered speeds is known. Therefore, detailed description thereof will be omitted.
Referring to FIG. 3 , the power of the engine ENG is transmitted to the second input shaft IS 2 by operation of the second clutch C 2 , the third sleeve SLE 3 of the third synchronizer SL 3 is engaged with the second forward speed clutch gear CG 2 , and the fourth sleeve SLE 4 of the fourth synchronizer SL 4 is engaged with the first forward speed clutch gear CG 1 at the first forward speed.
At this time, the rotation speed of the second input shaft IS 2 is input to the first transfer gear assembly TGA 1 as the negative rotation speed through the fourth input gear G 4 and the first transfer input gear TI 1 , and the negative rotation speed of the first transfer gear assembly TGA 1 is input to the second transfer input gear TI 2 as positive rotation speed through the first transfer output gear TO 1 and drives the first sun gear S 1 .
At this time, the carrier PC is connected to the second transfer gear shaft TS 2 though the fourth hub gear H 4 , the fourth sleeve SLE 4 and the first forward speed clutch gear CG 1 , and the second sun gear S 2 is engaged with the second pinion P 2 such that the rotating direction changing device RC becomes a direct-coupling state. Therefore, the power input to the first sun gear S 1 is transmitted to the second transfer gear shaft TS 2 without change of the rotation speed.
In this case the power of the second transfer gear shaft TS 2 is output to the differential apparatus DIFF through the second transfer output gear TO 2 , the second forward speed gear D 2 , the second forward speed clutch gear CG 2 , the second output shaft OS 2 , and the second output gear OG 2 .
At this time, speed ratio at the first forward speed is determined by gear ratios of the fourth input gear G 4 , the first transfer input gear TI 1 , the first transfer output gear TO 1 , the second transfer input gear TI 2 , the second transfer output gear TO 2 , and the second forward speed gear D 2 .
FIG. 4 is a schematic diagram illustrating flow of power at a reverse speed in a double clutch transmission according to an exemplary embodiment of the present invention. Referring to FIG. 4 , the power of the engine ENG is transmitted to the second input shaft IS 2 by operation of the second clutch CL 2 , the third sleeve SLE 3 of the third synchronizer SL 3 is engaged with the second forward speed clutch gear CG 2 , and the fourth sleeve SLE 4 of the fourth synchronizer SL 4 is engaged with the fixed clutch gear FC at the reverse speed.
At this time, the rotation speed of the second input shaft IS 2 is input to the transfer gear assembly TGA 1 as the negative rotation speed through the fourth input gear G 4 and the first transfer input gear TI 1 , and the negative rotation speed of the first transfer gear assembly TGA 1 is input to the second transfer input gear TI 2 as the positive rotation speed through the first transfer output gear TO 1 and drives the first sun gear S 1 .
At this time, since the fourth sleeve SLE 4 is engaged with the fixed clutch gear FC, the carrier PC is operated as the fixed element and the first sun gear S 1 is operated as the input element in the rotating direction changing device RC. Therefore, the negative rotation speed is output to the second sun gear S 2 .
Therefore, the second transfer gear shaft TS 2 fixedly connected to the second sun gear S 2 rotates inversely, and the negative rotation speed of the second transfer gear shaft TS 2 is output to the differential apparatus DIFF through the second transfer output gear TO 2 , the second forward speed gear D 2 , the second forward speed clutch gear CG 2 , the second output shaft OS 2 , and the second output gear OG 2 .
At this time, speed ratio at the reverse speed is determined by gear ratios of the fourth input gear G 4 , the first transfer input gear TI 1 , the first transfer output gear TO 1 , the second transfer input gear TI 2 , the second transfer output gear TO 2 , and the second forward speed gear D 2 .
Meanwhile, the parking brake gear PG is disposed at a front end portion of the second transfer gear shaft TS 2 and performs parking function.
According to various embodiments of the present invention, the first transfer gear assembly TGA 1 including one synchronizer SL 3 , two speed gears, and two gears is disposed on the second output shaft OS 2 , and the rotating direction changing device RC, one synchronizer SL 4 , and two gears are disposed on the second transfer gear shaft TS 2 disposed in parallel with the second output shaft OS 2 . Therefore, a length of the transmission may be shortened. Thereby, the transmission can be mounted in an engine compartment without layout change of the engine compartment. In addition, since the layout of the engine compartment is not changed, cost may be curtailed.
For convenience in explanation and accurate definition in the appended claims, the terms “front” or “rear”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.
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A double clutch transmission of a vehicle is disclosed. The double clutch transmission may selectively transmit power of a power source to two input shafts through two clutches and may output changed power through two output shafts after the power selectively transmitted to the two input shafts is changed. The two input shafts may respectively have a plurality of input gears fixed thereon, the two output shafts may respectively have a plurality of speed gears rotatable on the output shafts and a plurality of synchronizers operably connecting each speed gear to any one of the output shafts, and each input gear may be engaged with at least one speed gear.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the United States national phase of International Application No. PCT/NL2013/050245 filed Apr. 2, 2013, and claims priority to Netherlands Patent Application No. 2008577 filed Mar. 30, 2012, the disclosures of which are hereby incorporated in their entirety by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for determining a mass flow rate of a fluid in a conduit.
A further aspect of the invention relates to a method for determining a mass flow rate of a fluid in a conduit.
2. Description of Related Art
It is known per se to determine a mass flow rate of a fluid in a conduit. A free-flow milk meter which is currently commercially available determines the quantity of milk present in a part of the milk meter for a determined period of time. By integrating all values of determined measurement quantities the overall milk yield is calculated in a time segment.
A drawback of such a free-flow milk meter is that the determined milk yield often differs in practice from the actual milk yield.
SUMMARY OF THE INVENTION
The present invention has for its object to obviate or at least reduce such a drawback of the known art. The invention provides for this purpose a device for determining a mass flow rate of a fluid in a conduit, for instance a milk flow through a tube, the device comprising:
a measuring member for determining an electrical conductivity of the fluid; an additional measuring member for determining the electrical conductivity of the fluid at an additional position; and a processing unit for determining the mass flow rate of the fluid in the conduit on the basis of the determinations,
wherein the specific resistance can be determined per cross-sectional area in the flow.
An advantage of the device according to the invention is that the determined milk yield corresponds to the actual milk yield, or has at least an acceptable deviation.
The resistance of a fluid is directly proportional to the electrical conductivity of this fluid. This means that, when preferably the resistance at the position of a measuring member can be determined in a slice, more preferably substantially perpendicularly of the flow direction of the fluid, it is possible to determine the electrical conductivity of the fluid at the position of the measuring member. Using the known electrical conductivity it is possible to determine the characteristic density of the fluid at the position of the measuring member by means of formulae known to the skilled person in the field.
In the case the device is applied to measure a milk flow during the milking of a cow, it is then conceivable that the milk flow changes continuously. At one moment there will be more air and foam in the fluid flow than at the next moment. The characteristic density is therefore subject to change depending on the fluid flow. Owing to the fact that the characteristic density is subject to change and is determined at two separate positions, it is possible to determine the flow speed of the fluid, wherein this speed is determined a number of times within a predetermined period of time, for instance at a frequency of 2 kHz.
The characteristic density is further a measure of the actual quantity of milk at the position of the measuring member. It is possible to accurately determine the mass flow rate of the milk through the tube by measuring the actual quantity of milk at a determined point in time and also determining the flow speed at this same point in time.
The invention has diverse preferred embodiments which will become apparent from the following description of several such embodiments. The advantageous inventive features of the invention in all its aspects, including the measures defined in the dependent claims, are by no means limited to the considerations stated above and/or below.
A first preferred embodiment of a device according to the invention has the feature that the measuring member and/or the additional measuring member has/have a circular form. An advantage of this embodiment is that the measuring member can in this way be arranged on a surface of a conduit without changes being necessary to the conduit, which in practice is often already present. In the case a new tube is arranged, it is then possible to use a conventional tube, thereby for instance saving unnecessary costs.
A further preferred embodiment of a device according to the invention has the feature that the measuring member and/or the additional measuring member can be placed on an inner surface of the conduit so that the measuring member and/or the additional measuring member is in contact with the fluid during use. An advantage of this embodiment is that, because the measuring member is in direct contact with the fluid, the measuring results are better. Possible changes in the fluid are immediately detectable at the measuring member, so that smaller changes are also detectable.
A preferred embodiment of a device for determining a mass flow rate of a fluid in a conduit has the feature that each of the measuring member and the additional measuring member comprises an electrode pair. It is advantageous here for each electrode pair to comprise a first electrode and a second electrode which are arranged insulated from each other. Applied to the electrode pair is a wave signal, the current value of which is measured. When the current value is known, it is then possible via a per se known formula to determine the electrical conductivity of the fluid. The use of an electrode pair makes it possible in relatively simple manner to determine the electrical conductivity of the fluid at the position of the measuring member and/or the additional measuring member.
The insulation material is present for the purpose of preventing the current flowing via a path other than a current path through the fluid.
In a further preferred embodiment measurement takes place in potentiometric manner, preferably wherein a voltage is measured by means of passive electrodes on the basis of a signal supplied externally relative to the passive electrodes. An advantage hereof is that the effects of polarization are prevented. The measurement depends directly on the conductivity of the solution. Electrolysis is further prevented, whereby a wide range of conductivity can be measured. A further cost-saving can for instance be achieved by applying cheaper stainless steel electrodes instead of the more costly platinum electrodes.
The device more preferably comprises work electrodes for preferably providing a signal for the purpose of measurements by the measuring members. An advantage hereof is that a wide measurement range can be realized, it being for instance possible here to achieve such an advantage by applying varying voltages, which variation can be realized while the measurements are being performed, whereby a high output resolution can be obtained.
In a further preferred embodiment a combination of the measuring member and the additional measuring member is arranged in a pair of work electrodes, preferably wherein the work electrodes are arranged for the purpose of providing a signal to both measuring members.
In a further preferred embodiment the device comprises a data file or access to a data file, wherein the data file comprises data relating to a predetermined correlation between parameters relating to the mass flow rate, such as speed, vacuum level, claw air bleed, liner slip, fluid viscosity, flow regime, sensor angle, more preferably for the purpose of calculations for estimating the speed under the influence of such parameters, preferably comprising predetermined data relating to the speed from an earlier data series based on controlled test situations.
It hereby becomes possible to realize an accurate determination during these periods of laminar flow. A change is made for this purpose to standardized values for performing the calculations relating to the speed of the fluid. When the end of a laminar part of the flow is reached, provision is made that the calibration calculations are applied for matching qualitatively high-grade measurements with the standardized values. A balance is struck here in respect of the probability of the actual measurements and the known probability of the previously realized calibrated measurements.
The device more preferably comprises correlating means for correlating ongoing measurements with data of calibrated previous measurements.
According to a further preferred embodiment, the device further comprises a reference measuring member for performing reference measurements, preferably in potentiometric manner by means of a pair of work electrodes with measuring electrodes arranged therebetween, more preferably arranged in a protrusion, more preferably provided with an electrode pair which is configured to determine at least one reference value, such as the specific resistance, of the electrical conductivity of the fluid.
The electrical conductivity of a fluid, particularly milk, is subject to changes as a result of for instance salts present in the milk. The quantity of salts in the milk depends for instance on the feed which for instance a cow has eaten, or the environment in which the cow is located.
An electrical conductivity in substantially degassed milk can be determined by applying the reference measuring member, whereby a relation between the two becomes known. The electrical conductivity measured at the measuring member and the additional measuring member is plotted against the measured electrical conductivity of air and of stationary milk. An advantage hereof is that it is possible to determine how much milk is present at the position of the measuring member at the time of the measurement, particularly when circular measuring members, such as circular electrodes, are applied. Providing the reference measuring member in a bulge of the conduit achieves that the electrical conductivity of the milk without air is determined.
It is advantageous here for the additional measuring member to lie at a predetermined distance from the measuring member and for the additional measuring member to lie downstream of the measuring member in the arranged situation. It is in this way possible to determine the flow speed of the fluid on the basis of changes in the specific resistance/electrical conductivity in combination with the distance between the measuring member and the additional measuring member. When the speed is taken in combination with the characteristic density, it is then possible to determine the mass flow rate of the fluid through the conduit.
A further embodiment of the device according to the invention has the feature that the reference measuring member is provided upstream or downstream of the measuring member. An advantage of this embodiment is that during the measurement of the specific resistance the height of the measuring member and/or the additional measuring member is not affected by the reference measuring member.
A further preferred embodiment of the device according to the invention has the feature that a type of flow of the fluid through the conduit may be changed. Since the flow speed of the fluid through the tube is determined on the basis of changes in the specific resistance and/or electrical conductivity of the fluid, these changes also being brought about by a change in the quantity of milk at the position of the measuring member and/or the additional measuring member, determining of the flow speed of the fluid is simplified when the type of flow may be changed. The measuring results of the measuring member and/or the additional measuring member are influenced by the change in the type of flow, so that the flow speed of the fluid through the conduit can be properly determined.
It is advantageous here that a Kármán vortex street can be realized in the fluid flow, preferably by placing an object in the fluid flow. The inventor has discovered that such a vortex street has a positive effect on the measuring results of the measuring member and/or the additional measuring member. In other words, good results have been obtained using this vortex street.
A further preferred embodiment of the device according to the invention has the feature that during use a wave signal can be applied to each electrode pair. It is known per se that, when an electrode is arranged in a fluid, particularly a liquid, gas formation can occur on the surfaces of the electrode pair. In order to apply a wave signal to the electrode pair the polarity of each electrode is switched subject to the wave signal. An advantage hereof is that gas formation on the surfaces of the electrode pair is prevented.
A further aspect of the invention relates to a method for determining a mass flow rate of a fluid in a conduit, for instance a milk flow through a tube, the method comprising steps for:
applying a wave signal to a measuring member and an additional measuring member; determining an electrical conductivity of the fluid at the position of the measuring member and the additional measuring member; and determining the mass flow rate of the fluid on the basis of the determinations,
characterized by
repeating the step of determining the electrical conductivity within a predetermined period of time.
An advantage of this method is that, due to the fact that the flow speed of the fluid within the conduit is determined repeatedly, the mass flow rate of the fluid is determined repeatedly. The overall mass flow rate of the fluid through the conduit is hereby accurately determined.
A preferred embodiment of the method according to the invention has the feature that the predetermined period corresponds to a sampling frequency in a range of 1 kHz-20 kHz, preferably 1.5 kHz-10 kHz, preferably 1.8-5 kHz, preferably about 2 kHz. The inventor has discovered that at these frequencies the randomness of the determination of the mass flow rate of the fluid through the conduit falls within the desired accuracy. The higher the frequency, the more overlap there will occur between the different measurements. A result of this is that changes in the electrical conductivity/specific resistance of the fluid are followed accurately. The mass flow rate can hereby be determined more precisely.
It is advantageous here for the wave signal to have a form selected from the group comprising: sine, sawtooth and block. The form of the wave signal influences the results of the measurements, depending on the type of measurement. A result of this is that good measuring results can be obtained in a wide range of conditions.
A further preferred embodiment of the method according to the invention comprises steps for correlating the determination of the measuring member and the determination of the additional measuring member. It is in this way possible to determine the flow speed of the fluid in the conduit. A possible deceleration of the fluid between the measuring member and the additional measuring member will further be discerned during the correlation of the two determinations. The same will be the case for a decrease in an amplitude of the measurement signal.
The method more preferably comprises steps for applying the wave signal directly to electrodes of the measuring member, or steps for applying the wave signal to work electrodes, wherein the wave signal functions over measuring electrodes. Similar advantages as stated in the foregoing are hereby realized.
BRIEF DESCRIPTION OF THE DRAWINGS
Following below is a description of several embodiments which are shown in the accompanying drawings and provided only by way of example, and in which the same or similar parts, components and elements are designated with the same reference numerals, and in which:
FIG. 1 shows cross-sections of different types of flow;
FIG. 2 shows an embodiment of a device according to the invention.
FIG. 3 shows a graph with measurement signals;
FIG. 4 shows a schematic overview of an embodiment of the device according to the invention;
FIG. 5 shows different types of wave signal;
FIG. 6 shows a perspective view of a further preferred embodiment according to the present invention;
FIG. 7 shows a view of a detail of FIG. 6 ;
FIG. 8 shows a schematic representation of a preferred embodiment according to the present invention;
FIG. 9 shows a schematic representation of a further preferred embodiment according to the present invention; and
FIG. 10 shows a schematic representation of a measurement sequence according to a preferred embodiment according to the present invention.
DESCRIPTION OF THE INVENTION
FIG. 1 shows cross-sections of different types of flow. Each of the different types of flow produces a different measuring result, which is determined by means of the measuring member and the additional measuring member. The different types of flow have different distributions in respect of air L and milk M in the tube, as well as different ratios of milk and air L. The differences result in different types of measurement signal, wherein the measurement signals are a measure of the quantity of milk M present at the position of the measuring member. FIG. 1 a shows a laminar (stratified) flow, FIG. 1 b shows a bubble flow and FIG. 1 c shows a foam flow. The flow is moving through a tube 1 .
FIG. 2 shows an embodiment of a device according to the invention. In this embodiment the device is arranged on an inner surface of a tube 1 . The device comprises a first electrode pair 2 and a second electrode pair 3 arranged a determined distance D relative to each other. Each electrode pair 2 , 3 comprises a first electrode 8 , an insulating material 9 and a second electrode 10 . The electrode pairs 2 , 3 are connected to a control unit 4 which sends signals to the electrode pairs 2 , 3 and which determines the electrical conductivity of the fluid at the position of the electrode pairs 2 , 3 . Further provided is a chamber 7 in which two electrodes 5 , 6 are arranged. The fluid, such as milk, present in chamber 7 is substantially homogenous and comprises substantially no foam or air bubbles. On the basis of the substantially homogenous milk the specific resistance of the milk is determined in a per se known manner by means of electrodes 5 , 6 in the chamber. The specific resistance determined in chamber 7 is combined with the measurements of the electrical conductivity of the milk at the position of the electrode pairs 2 , 3 . It is in this way possible to determine how much milk is present at the position of the electrode pairs 2 , 3 at a determined point in time.
FIG. 3 shows a graph with measurement signals. Signal 1 is measured at the position of the first electrode pair 2 and signal 2 is measured at the position of the second electrode pair 3 . The distance between these electrode pairs 2 , 3 is known. The correlation between the two signals is determined by processing unit 4 so that the time the milk requires to move from the first electrode pair 2 to the second electrode pair 3 , indicated in the figure with V, can be determined. Since the distance between the two electrode pairs 2 , 3 is known, and the time the milk requires to move from the first electrode pair 2 to the second electrode pair 3 , it is possible to determine the speed of the milk.
Further shown in the figure is that a decrease in the amplitude of signal 2 compared to signal 1 is detected by means of the correlation and has no adverse effect on the determination of the speed of the milk flow inside tube 1 .
FIG. 4 shows a schematic overview of an embodiment of an electrode pair 2 , 3 according to the invention. Shown is a processing unit 4 , wherein the device is connected to a tube 1 . Electrode pairs E 1 and E 2 are connected to tube 1 , and so in contact with the fluid. Processing unit 4 generates a (digital) wave signal which is converted by the DAC. The output passes through resistor R and A 1 measures the current through R. The voltages over electrode pairs E 1 and E 2 are measured by A 2 . Both the measured current and voltage of respectively A 1 and A 2 are converted to digital by the ADC. Processing unit 4 transmits pulses to the ADC which coincide with the peaks of the generated wave signal. The ADC can hereby directly sample the maximum amplitude of the wave signal. The measured current and voltage samples are converted to digital and processing unit 4 calculates the electrical conductivity of the sample.
FIG. 5 shows different types of wave signal. The advantage of wave signals is that gas formation at the electrode pairs 2 , 3 can be prevented. The wave signal can be adapted to the fluid to be measured and to the measurement conditions, since each condition requires a different wave signal. Shown is a sawtooth signal and a waveform signal.
In the embodiment according to FIGS. 6 and 7 a measuring method is applied in accordance with the potentiometric principle. The embodiment relates to a measuring device 61 . Measuring members 2 ′, 3 ′ are arranged close to the side of a milk flow tube. Arranged on either side hereof are two work electrodes 62 , 63 so that the entity of measuring members 2 ′, 3 ′ is situated between the work electrodes. In this preferred embodiment the measurement signals are applied over work electrodes 62 , 63 , whereby the signals pass along both measuring members 2 ′, 3 ′.
Each of the measuring members 2 ′, 3 ′ is provided with a measuring electrode 8 ′, 9 ′ and 8 ″, 9 ″ respectively. The operation of each of the measuring members 2 ′, 3 ′ is as indicated in FIG. 9 . Work electrodes 62 , 63 ( 64 , 65 respectively in FIG. 9 ) provide as embodied in similar manner as in FIG. 4 a measurement signal over electrodes 8 ′, 9 ′ and 8 ″, 9 ″ respectively ( 5 ′, 6 ′ respectively in FIG. 9 ). The measurement is performed by means of a voltage measurement over electrodes 8 ′, 9 ′ and 8 ″, 9 ″ respectively.
The measurement data are transmitted in similar manner as on the basis of FIG. 4 to a processing unit. A difference between FIG. 6 and FIG. 9 is that in FIG. 6 with one pair of work electrodes two pairs of work electrodes are provided with a signal. Provided for here is that the measurement signals from measuring members 2 ′, 3 ′ can be alternately recorded separately of each other.
Formed close to the other end of measuring device 61 is a chamber 7 for providing a homogenous quantity of liquid therein. A reference measurement is performed on this homogenous quantity of liquid so that by means of calculations differences in the conductivity of the liquid flowing by, such as milk, in homogenous form can be eliminated from the calculations on the basis of the measuring members.
Where in the preferred embodiment according to FIG. 1 there are two electrodes for supplying the measurement signal and performing the measurement, in this preferred embodiment there are two work electrodes 64 , 65 for providing the signal and two measuring electrodes 5 ′, 6 ′ (electrodes 5 , 6 respectively in FIG. 8 ) for performing the measurement. It is therefore also the object in this preferred embodiment to perform the reference measurement close to the height measurement so that the variations in the conductivity of the fluid can be eliminated in isolation.
Shown schematically in FIG. 10 is the method of the embodiment according to FIG. 6-7 . The measurements by means of respective measuring members 2 ′, 3 ′ are shown in parallel on the left-hand side of the figure. A value for the resistance is provided in step 72 , 72 ′. The reference value is provided in step 75 . On the basis hereof, in combination with the temperature from step 76 , an electrical conductivity of the milk is determined in step 77 .
On the basis of the crude data relating to filling 73 , 73 ′ an estimated value 74 , 74 ′ in respect of the speed is either directly determined or, if the certainty in respect of the estimated value 74 , 74 ′ of the speed falls below a threshold value, a cross-correlation 80 is performed on the basis of values predetermined under calibrated conditions. The estimated values of the cross-correlation and of the direct measurement are compared in step 81 and modified subject to predetermined set parameters. A yield 82 is then determined on the basis hereof. These determinations can be performed outside the real time of the measurements, or corrections can be made.
The values 78 , 78 ′ in respect of an estimated flow speed are realized on the basis of the values 74 , 74 ′, after which estimated yields 79 , 79 ′ are determined on the basis hereof. Finally, these values are added in order to determine an estimated total mass of fluid 83 .
The present invention has been described in the foregoing on the basis of several preferred embodiments. Different aspects of different embodiments are deemed described in combination with each other, wherein all combinations which can be deemed by a skilled person in the field as falling within the scope of the invention on the basis of reading of this document are included. These preferred embodiments are not limitative for the scope of protection of this document. The rights sought are defined in the appended claims.
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The present invention relates to a device for determining a mass flow rate of a fluid in a conduit, for instance a milk flow through a tube. The device includes a measuring member for determining an electrical conductivity of the fluid; an additional measuring member for determining the electrical conductivity of the fluid at an additional position; and a processing unit for determining the mass flow rate of the fluid in the conduit on the basis of the determinations, wherein the specific resistance can be determined per cross-sectional area in the flow.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Japanese Patent Application No. 2012-138027 filed on Jun. 19, 2012, the entire subject matter of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] This disclosure relates to a power supply device able to detect mounting and demounting of an LED lamp in an LED illumination apparatus.
BACKGROUND
[0003] Recently, an illumination apparatus using white LEDs have been commercialized as a replacement for existing fluorescent lamps in a field of illumination. The LED illumination apparatuses have a merit that a life span thereof is longer than the fluorescent lamps. Also, because mercury is used in the fluorescent lamps, the LED illumination apparatuses are favored in terms of environmental burden.
[0004] In white LED illumination apparatuses, LED lamps are typically driven by a step-down chopper type DC/DC converter or a fly-back type DC/DC converter. For the LED lamps, a plurality of LED elements are connected in series to each other, thereby constantly keeping an electric current flowing through the LED elements, reducing a brightness variation between each LED element, and also ensuring a light intensity required for illumination.
[0005] Further, in a case of LED lamps requiring a higher light intensity, a plurality of rows of LED elements, which are connected in series to each other as described above, are connected in parallel to each other to form an LED group, thereby ensuring a higher light intensity.
[0006] However, although the LED illumination apparatuses have a long lifetime as described above, the LED illumination apparatuses have a finite life span of several ten thousand hours, and thus the LED lamps have to be replaced after all. In addition, because the LED lamps are configured by a plurality of LED elements connected in series to each other, if only one of the plurality of LED elements is disconnected/shorted, the LED lamps lose an illumination function, or the electric current flowing through the LED elements is increased, thereby shortening the life span.
[0007] To solve disconnection/short problems of the LED elements, JP-A-H06-291732 discloses an LED apparatus including a plurality of LED rows, each of which has a plurality of LED elements connected in series to each other and are connected in parallel to each other, and an electric current flowing through each LED group is detected by a detection resistor, so that a disconnection is detected based on decrease in voltage of the detection resistor.
[0008] Further, JP-A-2008-258428 discloses an LED illumination apparatus including an LED group having a plurality of LED rows connected in parallel to each other, in which a circuit open state is detected when an abnormality is occurred and thus any of LED rows are disconnected, so that an electric current of magnitude corresponding to LED rows having an abnormality is redistributed over LED rows other than the disconnected LED rows.
SUMMARY
[0009] However, although a method for detecting whether or not the LED rows are disconnected and also measures for suppressing reduction of light intensity are disclosed in the related art, there is no teaching with respect to replacement of the LED lamp.
[0010] Namely, it is not considered that, according to abnormality of the LED rows, the LED lamp is safely replaced with a normal LED lamp without stopping electricity supply to the LED illumination apparatus.
[0011] Accordingly, this disclosure provides at least an LED illumination system in which an LED lamp can be safely replaced and restored without stopping electricity supply to the LED illumination apparatus.
[0012] In view of the above, an LED illumination system of this disclosure comprises: a load including an LED lamp, which includes at least one of LED rows having a plurality of LED elements connected in series to each other, the LED rows being connected in parallel to each other; and a power supply device that supplies a direct current power to the load, the LED lamp configured to be physically mounted on and demounted from the power supply device, the power supply device comprising: a current feedback control unit having a detection resistor to detect an electric current flowing through the load, wherein the current feedback control unit is configured to compare a value of the electric current detected on the detection resistor with a predetermined reference value, thereby performing a constant current control; a first voltage comparison unit configured to determine whether the load is in a demounted state, according to a value of an output voltage of the power supply device; a voltage feedback control unit configured to decrease the voltage of the power supply device to a safe voltage when the load is demounted from a mounted state, and to increase the voltage of the power supply device to perform the constant current control when the load is mounted from the demounted state; and a semiconductor switch element connected in series between the load and the detection resistor, wherein the mounted and demounted states of the load is detected by a voltage of a main electrode of a high potential side of the semiconductor switch element.
[0013] According to the LED illumination system of this disclosure, an LED lamp can be safely replaced and restored without stopping electricity supply to the LED illumination system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The foregoing and additional features and characteristics of this disclosure will become more apparent from the following detailed descriptions considered with the reference to the accompanying drawings, wherein:
[0015] FIG. 1 is a configuration view illustrating an LED illumination apparatus according to a first aspect of this disclosure;
[0016] FIG. 2 is a sequence diagram illustrating an operation of each part when an LED lamp shown in FIG. 1 is mounted and demounted;
[0017] FIG. 3 is a sequence diagram illustrating an operation of each part until the LED lamp shown in FIG. 1 is mounted from a demounted state;
[0018] FIG. 4 is a configuration view illustrating an LED illumination apparatus according to a second aspect;
[0019] FIG. 5 is a sequence diagram illustrating an operation of each part when an LED lamp shown in FIG. 4 is mounted and demounted;
[0020] FIG. 6 is a sequence diagram illustrating an operation of each part from a demounted state of the LED lamp shown in FIG. 4 ; and
[0021] FIG. 7 is a circuit diagram illustrating a non-polarity LED lamp by which electricity can be received independently of polarity.
DETAILED DESCRIPTION
[0022] An LED illumination apparatus according to aspects of this disclosure will be now described with reference to the accompanying drawings. In the drawings, the same or similar components are designated by the same or similar reference numerals.
[First Aspect]
[0023] FIG. 1 is a configuration view illustrating an LED illumination apparatus according to a first aspect of this disclosure.
[0024] With reference to FIG. 1 , the configuration of the LED illumination system 1 according to the present aspect will be described. The LED illumination system 1 includes a direct current power source E, a power supply device 2 , and an LED lamps LEDS. A voltage of the direct current power source E is converted to a voltage driving the LED lamps LEDS by the power supply device 2 , and then supplied to the LED lamps LEDS through terminals TA 1 and TA 2 of the power supply device 2 . Although the power supply device 2 shown in FIG. 1 is configured as a fly-back type converter, the power supply device 2 may be configured as a step-up or step-down chopper type converter or the like, and the converter may also be substituted by other types.
[0025] The LED lamp LEDS includes terminals TA 1 and TA 2 and has a shape allowing for the LED lamp LEDS to be mounted and demounted as a unitary assembly on and from the power supply device 2 .
[0026] As shown in FIG. 1 , the LED lamp LEDS receives electricity in a polarity manner, in which the terminal TA 1 has a plus polarity and the terminal TA 2 has a minus polarity. However, the LED lamp LEDS may be replaced with a non-polarity LED lamp LEDS as shown in FIG. 7 .
[0027] The power supply device 2 shown in FIG. 1 is configured as a fly-back type DC/DC converter, and has a series circuit of a primary coil of a transformer T 1 and a switching element M 1 connected to the direct current power source E. A secondary circuit of the transformer T 1 is connected to a series circuit of a diode D 1 and a smoothing capacitor Co, and a voltage between both terminals of the smoothing capacitor Co become an output voltage outputted to the LED lamp LEDS.
[0028] Here, a negative electrode of the smoothing capacitor Co is connected to GND, and a positive electrode of the smoothing capacitor Co is connected to the terminal TA 1 . The terminal TA 1 is connected to a positive electrode of the LED lamp LEDS, and a negative electrode of the LED lamp LEDS is connected to the terminal TA 2 . The terminal TA 2 is connected to GND through a series circuit of a switching element M 2 and a current detection resistor R 3 .
[0029] In addition to the components described above, the fly-back type DC/DC converter is configured by a comparator PWM-COMP, a triangular wave oscillator OSC, a current feedback control unit and a voltage feedback control unit, and additionally includes a first voltage comparison unit, a second voltage comparison unit, a flip-flop circuit FF 1 and a switch SW 1 .
[0030] A gate of the switching element M 1 of the fly-back type DC/DC converter is connected with an output of the comparator PWM-COMP configured to generate a switching pulse, which is a gate driving signal, and an inverting terminal of the comparator PWM-COMP is connected to the triangular wave oscillator OSC. One of non-inverting terminals of the comparator PWM-COMP is connected to an output terminal of an error amplifier OPcc, which becomes the current feedback control unit. The other of the non-inverting terminals is connected to an output terminal of an error amplifier OPcv, which becomes the voltage feedback control unit. Here, the comparator PWM-COMP determines a pulse width of the switching pulse by comparing a triangular wave voltage from the triangular wave oscillator OSC, which is connected to the inverting terminal, with a signal voltage from any one of the current feedback control unit and the voltage feedback control unit, which are connected to the non-inverting terminals.
[0031] A non-inverting terminal of the error amplifier OPcc is connected to a reference voltage Vrc, which becomes a reference value of an electric current flowing through the LED lamp, and an inverting terminal thereof is connected to a connection node between the current detection resistor R 3 and the switching element M 2 .
[0032] Also, a non-inverting terminal of the error amplifier OPcv is connected to a reference voltage Vry and an inverting terminal thereof is connected to GND through a resistor R 2 and also connected to one of terminals of the switch SW 1 . The other terminal of the switch SW 1 is connected to the positive electrode of the smoothing capacitor Co through a resistor R 1 and also connected to a non-inverting terminal of a voltage comparator CPre, which constitutes the first voltage comparison unit. An inverting terminal of the voltage comparator CPre is connected to a first reference voltage Vrr.
[0033] The second voltage comparison unit is configured by a voltage comparator CPat, a second reference voltage Vra and a resistor R 4 . An inverting terminal of the voltage comparator CPat is connected to the second reference voltage Vra, and a non-inverting terminal thereof is connected to one of terminals of the resistor R 4 and a drain of the switching element M 2 . Also, the resistor R 4 is connected in parallel to a series circuit of the switching element M 2 and the current detection resistor R 3 , and the other terminal of the resistor R 4 is grounded to GND.
[0034] A setting terminal of the flip-flop FF 1 is connected with an output of the voltage comparator CPat of the second voltage comparison unit, and a reset terminal thereof is connected with an output of the voltage comparator CPre of the first voltage comparison unit. A Q output of the flip-flop FF 1 is connected to a gate of the switching element M 2 and a Qb (Q bar) output thereof is connected to a control terminal of the switch SW 1 .
[0035] The LED illumination system 1 as shown in FIG. 1 detects whether the LED lamp LEDS as a load is present or not, by the first voltage comparison unit and the second voltage comparison unit. In a state where the LED lamp LEDS is demounted, the first voltage comparison unit detects a demounted state and then resets the flip-flop FF 1 and also turns the switch SW 1 on, so that the voltage feedback control unit decreases an output voltage of the power supply device 2 to a safe voltage. As described above, the LED lamp LEDS is LED rows in which a plurality of LED elements are connected in series to each other, and thus a voltage of about 50 V to 100 V is typically required. Therefore, when the LED lamp LEDS is detached, a risk of electric shock has to be suppressed and thus the voltage is decreased to a safe voltage (DC 42 V or lower). The safe voltage can be set by a resistance ratio between the resistors R 1 and R 2 and the reference voltage Vrv.
[0036] Also, when the LED lamp LEDS as a load is mounted, the output voltage of the power supply device 2 is applied to the drain of the switching element M 2 through a resistor R 5 of the LED lamp LEDS. This is detected by the second voltage comparison unit and then the flip-flop FF 1 is set. Accordingly, the switching element M 2 is turned on and the switch SW 1 is turned off, so that control by the voltage feedback control unit is switched to control by the current feedback control unit. In other words, the LED lamp LEDS is connected with the output of the power supply device 2 through the series circuit of the switching element M 2 and the current detection resistor R 3 , and the power supply device 2 is controlled by the current feedback control unit so that an electric current flowing through the LED lamp LEDS becomes a constant current.
[0037] FIG. 2 is a sequence diagram illustrating an operation of each part when the LED lamp shown in FIG. 1 is mounted and demounted. Also, FIG. 3 is a sequence diagram illustrating an operation of each part from the demounted state of the LED lamp shown in FIG. 1 to mounting thereof.
[0038] Next, with reference to FIGS. 2 and 3 , an operation of each part of the LED illumination system 1 according to the present aspect will be described.
[0039] During times t 0 to t 3 as shown in FIG. 2 , the LED lamp LEDS is mounted on the power supply device 2 . At the time t 0 , the direct current power source E supplies power to the power supply device 2 and switching of the switching element M 1 is started, and thus the output voltage Vo starts to be increased.
[0040] When reaching the time t 1 , the non-inverting terminal of the comparator CPat of the second voltage detection unit, which is detecting a drain voltage of the switching element M 2 , exceeds the second reference voltage Vra, and thus an H-leveled output signal is inputted to the setting terminal of the flip-flop FF 1 . As a result, the flip-flop FF 1 is set, and thus an H-signal is outputted from the Q output. This H-signal is applied to the gate of the switching element M 2 , thereby turning the switching element M 2 on. Also, the Qb (Q bar) output is changed to an L-signal and as a result, the switch SW 1 is turned from on to off. Thus, a partial voltage of the output voltage Vo due to the resistors R 1 and R 2 , which has been inputted to the inverting terminal of the error amplifier OPcv of the voltage feedback control unit, is disconnected, and the inverting terminal of the error amplifier OPcv becomes a GND potential through the resistor R 2 . As a result, the output voltage of the error amplifier OPcv outputs an H-signal to the other non-inverting terminal of the comparator PWM-COMP, thereby stopping a function of the voltage feedback control unit of controlling the output voltage Vo.
[0041] Here, as the voltage feedback control unit is stopped, the output voltage Vo is further increased over the times t 1 to t 2 and then an electric current Io starts to flow in the LED lamp LEDS through the series circuit of the switching element M 2 and the current detection resistor R 3 . At the time t 2 , when the electric current Io flowing through the LED lamp LEDS reaches the current reference value Vrc of the error amplifier OPcc of the current feedback control unit, the output voltage of the error amplifier OPcc is outputted to the one non-inverting terminal of the comparator PWM-COMP so that a voltage value dropped by the current detection resistor R 3 is to be the same as a reference voltage corresponding to the current reference value Vrc. As a result, the electric current Io is controlled under a constant current control.
[0042] At the time t 3 , if the LED lamp LEDS as a load is demounted, the power supply device 2 becomes a no-load state and thus the output voltage Vo is suddenly increased. Therefore, when the output voltage Vo reaches the first reference voltage Vrr, an H-signal from the output of the comparator CPre of the first voltage comparison unit, which is detecting the output voltage Vo, is inputted to the reset terminal of the flip-flop FF 1 , thereby resetting the flip-flop FF 1 . As a result, the Qb output is inverted such that an H-signal is outputted to the control terminal of the switch SW 1 , thereby turning the switch SW 1 on. Also, the Q output outputs an L-signal, thereby turning the switching element M 2 off. Therefore, a partial voltage of the output voltage Vo due to the resistors R 1 and R 2 is inputted to the inverting terminal of the error amplifier OPcv of the voltage feedback control unit, and thus a control for decreasing the output voltage Vo to a voltage value, which is obtained by multiplying the resistance ratio between the resistors R 1 and R 2 by the reference voltage Vrv, namely for decreasing the output voltage Vo to the safe voltage, is started. Then, the output voltage Vo reaches and keeps a stable voltage at a time t 4 .
[0043] Also, at the time t 3 , since the LED lamp LEDS is demounted, the electric current Io flowing through the current detection resistor R 3 becomes zero, and thus the inverting terminal of the error amplifier OPcc of the current feedback control unit becomes the GND potential through the current detection resistor R 3 . Therefore, the output voltage of the error amplifier OPcc outputs an H-signal to the one non-inverting terminal of the comparator PWM-COMP, and thus a function of the current feedback control unit of controlling the output current Io is stopped. In other words, at the time t 3 , the output current Io control by the current feedback control unit is switched to the voltage control by the voltage feedback control unit.
[0044] At a time t 5 , if the LED lamp LEDS as a load is re-mounted, the drain voltage of the switching element M 2 becomes a partial voltage of the output voltage Vo due to the resistor R 5 and the resistor R 4 and exceeds a value of the second reference voltage Vra. The non-inverting terminal of the comparator CPat of the second voltage detection unit, which is detecting the drain voltage of the switching element M 2 , exceeds the second reference voltage Vra, and thus an H-leveled output signal is inputted to the setting terminal of the flip-flop FF 1 . As a result, the flip-flop FF 1 is set, and thus an H-signal is outputted from the Q output. This H-signal is applied to the gate of the switching element M 2 , thereby turning the switching element M 2 on. Also, the Qb (Q bar) output is changed to an L-signal and thus the switch SW 1 is turned from on to off. Thus, a partial voltage of the output voltage Vo due to the resistors R 1 and R 2 , which has been inputted to the inverting terminal of the error amplifier OPcv of the voltage feedback control unit, is disconnected, and the inverting terminal of the error amplifier OPcv becomes the GND potential through the resistor R 2 . Then, the output voltage of the error amplifier OPcv outputs an H-signal to the other non-inverting terminal of the comparator PWM-COMP, thereby stopping a function of the output voltage Vo control the voltage feedback control unit. Thus, the output voltage Vo is increased, and the electric current Io starts to flow in the LED lamp LEDS through the series circuit of the switching element M 2 and the current detection resistor R 3 .
[0045] At the time t 6 , when the electric current Io flowing through the LED lamp LEDS reaches the current reference value Vrc of the error amplifier OPcc of the current feedback control unit, the output voltage of the error amplifier OPcc is outputted to the one non-inverting terminal of the comparator PWM-COMP so that a voltage value dropped by the current detection resistor R 3 is to be the same as a reference voltage corresponding to the current reference value Vrc. As a result, the electric current Io is controlled under a constant current control.
[0046] Next, FIG. 3 is a sequence diagram illustrating an operation of each part when the direct current power source E supplies power to the power supply device 2 in a state where the LED lamp is demounted, and the description thereof is given below.
[0047] At a time t 7 , when the direct current power source E supplies power to the power supply device 2 , switching of the switching element M 1 is started, and thus the output voltage Vo starts to be increased.
[0048] When reaching a time t 8 , because the LED lamp LEDS has not been connected to the terminals TA 1 and TA 2 , the non-inverting terminal of the comparator CPat of the second voltage comparison unit is not applied with a voltage and thus becomes the GND potential through the resistor R 4 . Therefore, the flip-flop FF 1 remains in a reset state, and then the switch SW 1 keeps and an on-state and the switching element M 2 keeps an off-state. Also, an inverting terminal voltage of the error amplifier OPcc of the current feedback control unit becomes the GND potential through the current detection resistor R 3 , and thus the function thereof is stopped. In this case, because the switch SW 1 is on, the error amplifier OPcv of the voltage feedback control unit limits the output voltage Vo to the safe voltage.
[0049] Then, at a time t 9 , if the LED lamp LEDS as a load is mounted, the output voltage Vo is applied to the drain of the switching element M 2 through the resistor R 5 via the terminals TA 1 and TA 2 . The drain voltage of the switching element M 2 becomes a partial voltage of the output voltage Vo due to the resistor R 5 and the resistor R 4 and exceeds a value of the second reference voltage Vra. The non-inverting terminal of the comparator CPat of the second voltage detection unit, which is detecting the drain voltage of the switching element M 2 , exceeds the second reference voltage Vra, and thus an H-leveled output signal is inputted to the setting terminal of the flip-flop FF 1 . As a result, the flip-flop FF 1 is set, and thus an H-signal is outputted from the Q output. This H-signal is applied to the gate of the switching element M 2 , thereby turning the switching element M 2 on. Also, the Qb (Q bar) output is changed to an L-signal and as a result, the switch SW 1 is turned from on to off. Thus, a partial voltage of the output voltage Vo due to the resistors R 1 and R 2 , which has been inputted to the inverting terminal of the error amplifier OPcv of the voltage feedback control unit, is disconnected, and then the inverting terminal of the error amplifier OPcv becomes the GND potential through the resistor R 2 .
[0050] As a result, the output voltage of the error amplifier OPcv outputs an H-signal to the other non-inverting terminal of the comparator PWM-COMP, thereby stopping a function of the output voltage Vo control of the voltage feedback control unit. The output voltage Vo is increased, and then the electric current Io starts to flow in the LED lamp LEDS through the series circuit of the switching element M 2 and the current detection resistor R 3 . Also, the electric current Io flowing through the LED lamp LEDS is controlled under a constant current control by the current feedback control unit.
[0051] As described above, according to the LED illumination system 1 according of the present aspect, a replacement operation, in which a failed LED lamp is demounted and then a normal LED lamp is mounted, is to be safely performed without stopping electricity supply to the LED illumination apparatus.
[Second Aspect]
[0052] FIG. 4 is a configuration view illustrating an LED illumination apparatus according to a second aspect. In FIG. 4 , the components similar to those in FIG. 1 are designated by the same reference numerals, and thus the description thereof is omitted.
[0053] The LED illumination system la according to the second aspect has a configuration, in which a dropper-type constant current control unit is incorporated into the switching operation of the switching element M 2 of the first aspect. Namely, a voltage between main electrodes of the switching element M 2 is not used as a saturated region, but is set to become an unsaturated region causing a dropper operation, and also an electric current flowing through the LED lamp LEDS is controlled under a constant current control based on a voltage detected by the current detection resistor R 3 to become a constant current.
[0054] Meanwhile, a power feedback control unit is added instead of the current feedback control unit of the first aspect, so that the voltage between the main electrodes of the switching element M 2 becomes a predetermined unsaturated voltage.
[0055] Also, a peripheral portion of a comparator PWM-COMPa of a power supply device 2 a is similar to the peripheral portion of the comparator PWM-COMP of the first aspect, but it has a configuration changed to an application employing a general comparator (PWM-COMPa), in which the number of non-inverting terminals of the comparator PWM-COMP is changed from two to one.
[0056] Specifically, as shown in FIG. 4 , a non-inverting terminal of the comparator PWM-COMPa is connected with anodes of diodes D 2 and D 3 , and a cathode of the diode D 3 is connected to the output of the error amplifier OPcv of the voltage feedback control unit. Also, a cathode of the diode D 2 is connected to an output of an error amplifier OPpw of the power feedback control unit. This connection method is intended to control a non-inverting terminal voltage of the comparator PWM-COMPa by electric currents inputted from each error amplifier. A reference voltage Vrf as a bias source is connected to the non-inverting terminal of the comparator PWM-COMPa through a resistor R 6 .
[0057] Then, components of the second aspect different from those in FIG. 1 illustrating the configuration of the first aspect will be described in detail.
[0058] The dropper-type constant current control unit including the switching element M 2 is configured by an error amplifier OPcc, a reference voltage Vrc, a switch SW 2 , a detection resistor R 3 , a resistor R 7 and a capacitor C 3 . A non-inverting terminal of the error amplifier OPcc is connected to the reference voltage Vrc, and an inverting terminal thereof is connected to a connection node between a source of the switching element M 2 and the detection resistor R 3 and is also connected to one of terminals of the capacitor C 3 and to one of terminals of the resistor R 7 . An output terminal of the error amplifier OPcc is connected to one of terminals of the switch SW 2 and to the other terminal of the capacitor C 3 , and the other terminal of the switch SW 2 is connected to a gate of the switching element M 2 and the other terminal of the resistor R 7 .
[0059] Also, the Q output of the flip-flop FF 1 is connected to a control terminal of the switch SW 2 . This is different in that, in FIG. 1 , the Q output of the flip-flop FF 1 is connected to the gate of the switching element M 2 .
[0060] The dropper-type constant current control unit including the switching element M 2 detects an electric current Io of the LED lamp LEDS as a load on the detection resistor R 3 , compares the detected voltage with the reference voltage Vrc by the error amplifier OPcc, and then controls a gate voltage of the switching element M 2 through the switch SW 2 so that the detected voltage has the same voltage value as that of the reference voltage Vrc. However, the condition causing a constant current operation to be performed requires that the Q output of the flip-flop FF 1 is an H-level and the switch SW 2 is on.
[0061] The power feedback control unit is configured by an error amplifier OPpw, a reference voltage Vrp, a capacitor C 1 and the diode D 2 . A non-inverting terminal of the error amplifier OPpw is connected to the reference voltage Vrp, and an inverting terminal thereof is connected to a drain of the switching element M 2 , a non-inverting terminal of a comparator CPat of a second voltage comparison unit and one of terminals of a resistor R 4 . An output terminal of the error amplifier OPpw is connected to the non-inverting terminal of the comparator PWM-COMPa through the diode 2 as described above, and also the capacitor C 1 is connected between the output terminal and the inverting terminal of the error OPpw.
[0062] A operation of the power feedback control unit is similar to the current feedback control unit shown in FIG. 1 , but it is different in that, in FIG. 1 , the electric current Io is controlled to eliminate an error between the value detected on the resistor R 3 and the reference voltage Vrc in FIG. 1 , whereas, in FIG. 4 , the output voltage of the power supply device 2 a is controlled to eliminate an error between a drain voltage of the switching element M 2 and the reference voltage Vrp.
[0063] FIG. 5 is a sequence diagram illustrating an operation of each part when the LED lamp shown in FIG. 4 is mounted and demounted. Also, FIG. 6 is a sequence diagram illustrating an operation of each part from a demounted state of the LED lamp shown in FIG. 4 .
[0064] Next, with reference to FIGS. 5 and 6 , an operation of each part of the LED illumination system la according to the second aspect will be described.
[0065] During times t 0 to t 3 as shown in FIG. 5 , the LED lamp LEDS is mounted on the power supply device 2 a. At the time t 0 , the direct current power source E supplies to the power supply device 2 a, and switching of the switching element M 1 is started, and thus the output voltage Vo starts to be increased. When reaching the time t 1 , the non-inverting terminal of the comparator CPat of the second voltage detection unit, which is detecting the drain voltage of the switching element M 2 , exceeds the second reference voltage Vra, and thus an H-leveled output signal is inputted to the setting terminal of the flip-flop FF 1 . As a result, the flip-flop FF 1 is set, and thus an H-signal is outputted from the Q output. This H-signal is applied to the control terminal of the switch SW 2 , thereby turning the switch SW 2 on. Therefore, although the constant current control unit becomes an operating state, the output voltage Vo does not reach a voltage causing an electric current to flow to the LED lamp LEDS, and thus the electric current Io does not yet flow at the time t 1 .
[0066] Also, the Qb (Q bar) output is changed to an L-signal, and thus the switch SW 1 is turned from on to off. Thus, a partial voltage of the output voltage Vo due to the resistors R 1 and R 2 , which has been inputted to the inverting terminal of the error amplifier OPcv of the voltage feedback control unit, is disconnected and the inverting terminal of the error amplifier OPcv becomes a GND potential through the resistor R 2 . As a result, the output voltage of the error amplifier OPcv outputs an H-signal to the cathode of the diode D 3 , thereby stopping a function of the voltage feedback control unit of controlling the output voltage Vo.
[0067] Here, as the voltage feedback control unit is stopped, the output voltage Vo is further increased over the times t 1 to t 2 , and the electric current Io starts to flow in the LED lamp LEDS through the series circuit of the switching element M 2 and the detection resistor R 3 . At the time t 2 , when the electric current Io flowing through the LED lamp LEDS reaches the current reference value Vrc of the error amplifier OPcc of the constant current control unit, the error amplifier OPcc controls the gate voltage of the switching element M 2 through the switch SW 2 so that a voltage value dropped by the detection resistor R 3 is to be the same as a reference voltage corresponding to the current reference value Vrc. In addition, immediately after the time t 2 , the power feedback control unit controls the non-inverting terminal voltage of the comparator PWM-COMPa so that the drain voltage of the switching element M 2 has a value similar to that of the reference voltage Vrp, thereby controlling the output voltage Vo of the power supply device 2 a.
[0068] At the time t 3 , if the LED lamp LEDS as a load is demounted, the power supply device 2 a becomes a no-load state, and thus the output voltage Vo is suddenly increased. In this case, when the output voltage Vo reaches the first reference voltage Vrr, an H-signal from the output of the comparator CPre of the first voltage comparison unit, which is detecting the output voltage Vo, is inputted to the reset terminal of the flip-flop FF 1 , thereby resetting the flip-flop FF 1 .
[0069] As a result, the Qb output is inverted such that an H-signal is outputted to the control terminal of the switch SW 1 , thereby turning the switch SW 1 on. Also, the Q output outputs an L-signal, thereby turning the switch SW 2 off. Therefore, a partial voltage of the output voltage Vo due to the resistors R 1 and R 2 is inputted to the inverting terminal of the error amplifier OPcv of the voltage feedback controller, and thus a control for decreasing the output voltage Vo to a voltage value, which is obtained by multiplying the resistance ratio between the resistors R 1 and R 2 by the reference voltage Vrv, namely for decreasing the output voltage Vo to the safe voltage, is started. Then, the output voltage Vo reaches and keeps a stable voltage at a time t 4 .
[0070] In addition, at the time t 3 , because the switch SW 2 is turned off, the switching element M 2 is also turned off and thus a function of the output current Io control of the constant current control unit is stopped. Also, as the switching element M 2 is turned off, an inverting terminal voltage of the power feedback control unit becomes the GND potential through the resistor R 4 , and thus the output voltage of the error amplifier OPpw outputs an H-signal to the cathode of the diode D 2 . As a result, at the time t 3 , the PWM control of the power supply device 2 a is switched from the control by the power feedback control unit to the voltage control by the voltage feedback control unit.
[0071] At a time t 5 , if the LED lamp LEDS as a load is re-mounted, the drain voltage of the switching element M 2 becomes a partial voltage of the output voltage Vo due to the resistor R 5 and the resistor R 4 and exceeds a value of the second reference voltage Vra. The non-inverting terminal of the comparator CPat of the second voltage detection unit, which is detecting the drain voltage of the switching element M 2 , exceeds the second reference voltage Vra, and thus an H-leveled output signal is inputted to the setting terminal of the flip-flop FF 1 . As a result, the flip-flop FF 1 is set, and thus an H-signal is outputted from the Q output. This H-signal is applied to the control terminal of the switch SW 2 , thereby turning the constant current control unit and the switching element M 2 on. Also, the Qb (Q bar) output is changed to an L-signal and as a result, the switch SW 1 is turned from on to off. Thus, a partial voltage of the output voltage Vo due to the resistors R 1 and R 2 , which has been inputted to the inverting terminal of the error amplifier OPcv of the voltage feedback control unit, is disconnected and the inverting terminal of the error amplifier OPcv becomes the GND potential through the resistor R 2 . As a result, the output voltage of the error amplifier OPcv outputs an H-signal to the cathode of the diode D 3 , thereby stopping a function of the voltage feedback control unit of controlling the output voltage Vo. The output voltage Vo is increased and the electric current Io starts to flow in the LED lamp LEDS through the series circuit of the switching element M 2 and the current detection resistor R 3 .
[0072] At the time t 6 , when the electric current Io flowing through the LED lamp LEDS reaches the current reference value Vrc of the error amplifier OPcc of the constant current control unit, the output of the error amplifier OPcc controls the gate voltage of the switching element M 2 through the switch SW 2 so that a voltage value dropped by the detection resistor R 3 is to be the same as a reference voltage corresponding to the current reference value Vrc, and as a result, the electric current Io flowing through the LED lamp LEDS is controlled under a constant current control. In addition, similarly to those immediately after the time t 2 , the power feedback control unit controls the non-inverting terminal voltage of the comparator PWM-COMPa so that the drain voltage of the switching element M 2 has a value similar to that of the reference voltage Vrp, thereby controlling the output voltage Vo of the power supply device 2 a.
[0073] Next, FIG. 6 is a sequence diagram illustrating an operation of each part when the direct current power source E supplies power to the power supply device 2 a in a state where the LED lamp is demounted, and the description thereof is given below.
[0074] At a time t 7 , when the direct current power source E supplies power to the power supply device 2 a, switching of the switching element M 1 is started, and thus the output voltage Vo starts to be increased.
[0075] When reaching a time t 8 , because the LED lamp LEDS has not been connected to the terminals TA 1 and TA 2 , the non-inverting terminal of the comparator CPat of the second voltage comparison unit is not applied with a voltage and thus becomes the GND potential through the resistor R 4 . Therefore, the flip-flop FF 1 remains in a reset state, and the switch SW 1 keeps an on state and the switch SW 2 and the switching element M 2 keeps an off-state. Also, the inverting terminal voltage of the error amplifier OPpw of the power feedback control unit becomes the GND potential through the detection resistor R 4 , and thus the function thereof is stopped. In this case, because the switch SW 1 is on, the error amplifier OPcv of the voltage feedback control unit limits the output voltage Vo to the safe voltage.
[0076] Then, at a time t 9 , if the LED lamp LEDS as a load is mounted, the output voltage Vo is applied to the drain of the switching element M 2 through the terminals TA 1 and TA 2 , i.e., the resistor R 5 . The drain voltage of the switching element M 2 becomes a partial voltage of the output voltage Vo due to the resistor R 5 and the resistor R 4 and exceeds a value of the second reference voltage Vra. The non-inverting terminal of the comparator CPat of the second voltage detection unit, which is detecting the drain voltage of the switching element M 2 , exceeds the second reference voltage Vra, and thus an H-leveled output signal is inputted to the setting terminal of the flip-flop FF 1 . As a result, the flip-flop FF 1 is set, and thus an H-signal is outputted from the Q output and the switch SW 2 is turned on. Also, the constant current control unit starts to be operated and the switching element M 2 is turned on.
[0077] Also, the Qb (Q bar) output is changed to an L-signal and as a result, the switch SW 1 is turned from on to off. Thus, a partial voltage of the output voltage Vo due to the resistors R 1 and R 2 , which has been inputted to the inverting terminal of the error amplifier OPcv of the voltage feedback control unit, is disconnected and the inverting terminal of the error amplifier OPcv becomes the GND potential through the resistor R 2 . As a result, the output voltage of the error amplifier OPcv outputs an H-signal to the cathode of the diode D 3 , thereby stopping a function of the voltage feedback control unit of controlling the output voltage Vo. The output voltage Vo is further increased, and the electric current Io starts to flow in the LED lamp LEDS through the series circuit of the switching element M 2 and the detection resistor R 3 . At a time t 10 , the electric current Io flowing through the LED lamp LEDS is controlled under a constant current control by the constant current control unit. In addition, immediately after the time t 10 , the voltage feedback control unit also starts to be operated, and thus the power supply device 2 a is controlled by the voltage feedback control unit.
[0078] As described above, similarly to the first aspect, the LED illumination system la according to the second aspect allows a replacement operation, in which a failed LED lamp is demounted and then a normal LED lamp is mounted, to be safely performed without stopping electricity supply to the LED illumination apparatus.
[0079] In the foregoing, although examples of aspects of this disclosure has been described, this disclosure is not limited to the above specific aspects, and accordingly, various changes and modifications thereof may be made within the scope of this disclosure as defined by the appending claims. For example, although the power supply device has been described using the fly-back type DC/DC converter, the converter may be changed to a forward type, or a step-up or step-down chopper-type.
[0080] In addition, the LED lamp LEDS as a load may be appropriately changed to an LED lamp LEDSa shown in FIG. 7 , by which electricity can be received independently of polarity.
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An LED illumination system includes: a load including an LED lamp; and a power supply device, the LED lamp configured to be physically mounted on and demounted from the power supply device, the power supply device comprising: a current feedback control unit; a first voltage comparison unit configured to determine whether the load is in a mounted state; a voltage feedback control unit configured to decrease the voltage of the power supply device to a safe voltage when demounting, and to increase the voltage of the power supply device to perform the constant current control when mounting; and a semiconductor switch element connected in series between the load and the detection resistor, wherein the mounted and demounted states of the load is detected by a voltage of a main electrode of a high potential side of the semiconductor switch element.
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RELATED APPLICATION
The present invention relates to application Ser. No. 08/546,778, filed Oct. 23, 1995 now abandoned, for FIXED MOUNT IMAGER USING OPTICAL MODULE.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to electro-optical systems for reading a one or two-dimensional bar code symbology, and more particularly, to a generic handheld symbology scanner that can be adapted for various uses by selection of a removable modular optical unit.
2. Description of Related Art
Within the automatic data identification and collection industry, electro-optical systems are commonly used to decipher data symbols printed on objects in order to identify information regarding the objects. A conventional bar code symbol represents a one-dimensional form of symbology, and comprises a pattern of vertical bars of various widths separated by spaces of various widths. Since the bar and space elements have different light reflecting characteristics, a reader can convert the symbology into an electrical signal by analyzing the light reflected from the symbol. The electrical signal can then be decoded to provide an alphanumeric representation of the symbol which identifies the object. Bar code symbols of this nature are now in common usage in various types of applications, such as inventory management and control, point of purchase identification, logistical tracking systems, or time and attendance record keeping.
A bar code scanner typically uses a light source that is drawn, or scanned, across the bar code field. Since the bar code symbol is often disposed on the object to be identified, it is desirable for the scanner to be included in a handheld or portable device so that the scanner can be brought to the object. Light emitting diodes (LEDs) are often utilized to provide the light source due to their light weight and low power requirements. The operator can physically move the LED across the bar code field, such as by use of a light pen. Though advantageous for some applications, these LED scanners have a rather limited scanning range. Greater scanning range can be achieved by a bar code scanner that includes movable mirrors to automatically articulate a light beam from a laser emitting source back and forth at a high rate to scan the light beam across the bar code field. Another scanning approach is to utilize a one-dimensional charge-coupled device (CCD) having a single one-dimensional row of imaging elements. The CCD device converts the printed information of the bar code symbol into an electrical signal representation. A one-dimensional CCD scanner can read an entire bar code symbol at once without requiring movement of the light source, as is necessary with the LED or laser emitting systems described above. As with the articulated laser scanners, however, one-dimensional CCD scanners are orientation dependent and must be aligned with the bar code symbol to accurately collect the information.
Since the conventional one-dimensional symbology requires a relatively large amount of space to convey a correspondingly small amount of data, so-called two-dimensional symbologies have been developed. A two-dimensional symbology may comprise a matrix that occupies a uniform amount of space having a generally rectangular or square shape. Instead of bars and spaces, round or square dots disposed at particular rows and columns of the matrix correspond to the characters being conveyed. As a result, a matrix symbology can compress significantly more data into a given volume of space than a conventional one-dimensional bar code. Examples of commercially available two-dimensional symbologies include Code One, Data Matrix, and PDF417.
Though some two-dimensional symbologies may be read using the conventional scanners described above, another approach is to convert the two-dimensional symbol into pixel information that is deciphered into the alphanumeric information represented by the symbology data. Such two-dimensional scanners may utilize two-dimensional CCD devices to obtain an optical image of the symbol and convert it into an electrical signal. These two-dimensional CCD scanners are not orientation dependent like the one-dimensional CCD or laser scanners, since the electrical signal may be processed to determine the rotational orientation of the symbol, remove any extraneous information, and thereby recover the alphanumeric information of the symbol. Thus, these two-dimensional scanners provide greater flexibility to the operator by permitting a symbol to be effectively read from a wide assortment of angles and orientations. An additional advantage of these two-dimensional scanners is that they can also be utilized to read one-dimensional symbology data, such as a conventional bar code symbol.
A drawback of each of the types of one and two-dimensional scanners described above is that they are not interchangeable and thus cannot be converted from one type to another. Each scanner type is optimized to use only one of the aforementioned optical sensors (e.g., LED, laser, CCD, etc.), which is mechanically and electrically integrated into the scanner in a permanent and non-removable manner. Since each scanner type has certain symbol reading applications for which it is most proficient and best suited, a user would select a scanner that is optimized for each particular application. Even if a user only utilizes scanners of the two-dimensional CCD type, there are differences in optical characteristics between individual scanners. For example, one type of CCD scanner may include focusing systems (i.e., lenses) optimized for scanning distances of less than one foot, while another type of CCD scanner may be optimized for distances of three to five feet. While a user can be ready for any scanning application by maintaining a supply of various types of scanners, it can be appreciated that this greatly increases the cost and complexity of operating an automatic data identification and collection system.
Accordingly, a critical need exists for an interchangeable scanner that can be optimized for various different applications. Moreover, such an interchangeable scanner should be able to operate with any type of optical sensor, and have a wide assortment of focusing characteristics.
SUMMARY OF THE INVENTION
An apparatus for scanning a one or two-dimensional bar code symbol is provided with an interchangeable optical sensor that can optimize the scanning apparatus for various different applications.
In a first embodiment of the invention, the scanning apparatus comprises a scanner body portion having a cover that may be opened to expose a receptacle. A scanning control unit is disposed within the body portion separate from the receptacle and has an electrical connection that extends through the body portion to the receptacle. A removable optical module is adapted to engage the receptacle and connect electrically to the scanning control unit through the electrical connection. The module includes an optical sensor adapted to receive light reflected from the bar code symbol through an opening of the body portion and convert the light into data representative of the symbology. The data is thereby provided to the scanning control unit. The optical sensor may comprise either a one or two-dimensional charge-coupled device, or an articulated laser.
In a second embodiment of the invention, the cover for the scanner body comprises an internal slot that extends from the opening provided in the cover. The optical module is adapted to slidable engage the slot, and a locking mechanism secures the optical module within the slot upon reaching a maximum extent thereof. An electrical connector provided in the receptacle is adapted to engage a corresponding electrical connector of the optical module upon operation of the locking mechanism. The optical module may thereafter be selectively removed from the slot by disengagement of the locking mechanism.
A more complete understanding of the generic handheld symbology scanner with a modular optical sensor will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of the preferred embodiment. Reference will be made to the appended sheets of drawings which will first be described briefly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a handheld symbology scanner;
FIG. 2 is a side view of the scanner of FIG. 1, with the cover opened to expose a modular optical sensor of the present invention;
FIG. 3 is a perspective view of the scanner with the cover omitted showing a top portion of the modular optical sensor;
FIG. 4 is a sectional view of the modular optical sensor coupled to the scanner;
FIG. 5 is a block diagram illustrating the functional elements of the modular optical sensor and the scanner;
FIG. 6 is a partial side sectional view of an alternative embodiment of the handheld scanner illustrating a modular optical sensor extracted outwardly of the scanner;
FIG. 7 is a top sectional view of the alternative embodiment of the handheld scanner taken through the section 7--7 of FIG. 6; and
FIG. 8 is a partial side sectional view of the alternative embodiment of the handheld scanner with the modular optical sensor inserted into the scanner.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention satisfies the critical need for an interchangeable scanner that can be optimized for various different applications. In the detailed description that follows, like element numerals are used to describe like elements illustrated in one or more of the figures.
Referring first to FIG. 1, a handheld scanner 10 is illustrated. The scanner 10 comprises a hand-held device having a handle 12 with a trigger 15, and a scan head 14. The handle 12 has a shape that is intended to conform to an operator's hand, with the trigger 15 positioned in relation to the operator's index finger. The scan head 14 includes a cover 16 having an opening 13 provided therein to permit light reflected from the object to be projected therethrough onto the operative elements inside the scan head which will be described below. The cover 16 may be opened or detached from the scan head 14, as will also be described below. The scanner 10 may further have a keypad (not shown) to enable the entry of operator defined data pertaining to a particular scanning operation.
As known in the art, the scanner 10 can be oriented selectively by an operator to position a bar code symbol to be scanned within a field of view of the scanning apparatus. The bar code symbol may be disposed on a document or other such object, and may comprise a one or two-dimensional bar code symbol. To operate the scanner 10, the operator orients the scanner so that the opening 13 is directed generally toward the bar code symbol within the limited field of view of the scanner. The operator pulls back on the trigger 15, which causes the bar code symbol to become momentarily illuminated by a light source disposed within the scan head 14. Light reflected off of the bar code symbol passes back through the opening 13 onto an imaging element within the scan head 14. The imaging element then converts the reflected light into data which represents the bar code symbol.
The scanner 10 is adapted to communicate with a central processor (not shown) over a radio frequency (RF) or hard-wired communication link. To enable RF communication, the scanner 10 may include an antenna 18 for communicating RF signals. Alternatively, a cable (not shown) may be provided in place of the antenna 26 to enable hard-wired communication. The central processor may include a computer or a network of computers configured to communicate with one or more of such scanners 10 that are operating within a common environment, such as a factory, warehouse, or retail establishment.
Referring now to FIGS. 2-4, the scanner 10 is shown with the cover 16 pivoted upward to an open position. The cover 16 may be attached to the scan head 14 by a hinge 25 disposed at a back end of the scan head, and may further include flexible hook members 27 that are adapted to couple with corresponding openings in the scan head 14 to form a snap-fit engagement. Alternatively, the cover may simply be attached to the scan head 14 using screws or the like, and may be entirely removable from the scan head.
With the cover 16 opened, an optical sensor module 20 of the present invention is visible. The sensor module 20 comprises a generally rectangular housing that fits snugly within a corresponding receptacle 19. As shown in FIGS. 3 and 4, a pair of screws 26 extend through a bore provided in a portion of the housing to secure the sensor module 20 to the scan head 14. Alternatively, the sensor module 20 may form a snap fit engagement with the receptacle 19 to avoid the need for screws. An electrical connector 17 coupled to the scan head 14 is adapted to engage a corresponding connector 22 of the sensor module 20 to provide an electrical connection between the sensor module 20 and the other elements of the scanner 10, as will be further described below. Respective ones of the connectors 17, 22 may be provided with male and female elements as is well known in the art. The sensor module 20 further includes a window 28 which allows light to enter and exit the sensor module through the opening 13 provided in the cover 16. In addition, flash elements 24 are mounted to the front surface of the sensor module 20 adjacent to the window 28. It is anticipated that the sensor module 20 be an entirely sealed unit that communicates with the scanner 10 only through the connectors 17, 22.
A block diagram of the functional elements of the bar code scanner 10 and sensor module 20 is shown in FIG. 5. The functional elements of the scanner 10 are disposed in a space provided with the handle 12. The bar code scanner 10 includes a digital signal processor 42, a memory 48, and an input/output (I/O) device 46. The digital signal processor 42 controls the sensor module 20 and is coupled to the memory 48 and the I/O device 46. The digital signal processor 42 may further include an internal memory space or read only memory (ROM) that contains a set of instructions or program to be executed by the digital signal processor. The memory 48 may comprise a conventional semiconductor random access memory (RAM) device. The I/O device 46 controls communications between the scanner 10 and the central processor. Particularly, the I/O device 46 is coupled to the hard-wired communication link described above, or may include an RF modulator that permits digital signals from the scanner 10 to be communicated to the central processor over the RF communication link described above. It should be apparent that the I/O device 46 may be configured to communicate digital signals by use of other known forms of wireless media, such as infrared communication. The scanner 10 may additionally include a power source to enable remote operation, such as a battery.
The sensor module 20 includes a sensor 36 that converts an optical image into electrical signals, such as a charge coupled device (CCD). A CCD comprises a one or two-dimensional array of photodiodes that respectively emit an electrical signal that varies with the intensity of light projected onto the surface of the CCD. The sensor module 20 may further include imaging optics 32 having fixed or variable focusing to control the focal length within the limited field of view of the sensor module 20. The flash element 24 provides illumination onto the bar code symbol of interest, and may be provided by a xenon tube. The intensity and time duration of the light provided by the flash element 24 may be variable. A control logic unit 34 provides control signals to each of the scanning sensor 36 and the flash element 24, and receives an input signal from the digital signal processor 42 to activate a scanning sequence.
The scanning sensor 36 provides an output signal that is converted from analog to digital by an analog-to-digital (A/D) converter 38 and then transferred to the digital signal processor 42. Particularly, the electrical signal generated by each photodiode of the scanning sensor 36 is converted into a binary number that represents a gray scale value of a corresponding area of the illuminated object. The digital signal processor 42 directs the control logic unit 34 and processes the data from the A/D converter into information representative of the bar code symbol, which is then stored in the memory 48. Each of these signals between the sensor module 20 and the digital signal processor 42 pass through the connectors 17, 22. Electrical power may also be provided to the sensor module 20 through the connectors 17, 22.
Referring now to FIGS. 6-8, an alternative embodiment of the scanner 10' is illustrated. As in the previous embodiment, the scanner 10' comprises a hand-held device having a handle 12 with a trigger 15, and a scan head 14. The scan head 14 includes a cover 56 having an opening 13 provided therein to permit light reflected from the object to be projected therethrough onto the operative elements inside the scan head which will be described below. Unlike the previous embodiment, however, the cover 56 remains rigidly coupled to the scan head 14, and a sensor module 50 is inserted into the cover 56 through the opening 13.
More particularly, a slot is formed within the cover 56 which is defined by an upper surface 62 and a lower surface 66. A connector 67 is disposed at an end of the slot opposite from the opening 13, and provides electrical connection to the elements of the scanner 10' in the same manner as the connector 17 of the previous embodiment. A rectangular slit 64 is provided at opposite side surfaces of the cover 56, such that the slits extend parallel with the slot provided within the cover. The sensor module 50 is generally rectangular and is dimensioned to slidably engage the slot between the upper and lower surfaces 62, 66. The sensor module 50 further comprises a connector 52 provided at an end thereof in substantial alignment with the connector 67. A latching mechanism is provided on the sides of the sensor module 50, which includes a flexible arm member 54 with a catch 56 provided at an end thereof.
When the sensor module 50 is inserted into the slot, the catch 56 and flexible arm member 54 are deflected inward until the catch is coincident with the forward end of the slit 64, whereupon the catch snaps into the slit to secure the sensor module in place within the slot. The connectors 52, 67 become engaged to electrically connect the sensor module 50 with the scanner 10' upon the sensor module being fully inserted into the slot. To remove the sensor module 50 from the scanner 10', the catch 56 is pressed inwardly by an operator which causes the sensor module to become dislodged and eject outwardly from the slot.
By providing sensor modules with a standard size and electrical connection, the sensor module may be easily detached from the scanner 10 and replaced with another sensor module having different optical or performance characteristics. For example, a plurality of sensor modules could be provided that each have different focusing characteristics, or which use a one-dimensional CCD array rather than a two-dimensional array. Alternatively, the sensor module 20 could be provided with an entirely different type of optical sensor, such as one that utilizes an articulating laser. An operator can select a sensor module having characteristics that suit a particular purpose. As new scanning technologies are developed in the future, sensor modules can be manufactured using the new technologies to update existing scanners in the field. Lastly, the detachable sensor module permits an operator to replace a module that has become inoperable, allowing the scanner 10 to remain in use. It can be appreciated that the detachable sensor module of the present invention would substantially enhance the interoperability and flexibility of the scanner.
Having thus described a preferred embodiment of a generic handheld symbology scanner, it should be apparent to those skilled in the art that certain advantages of the described system have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. The invention is further defined by the following claims.
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A scanning apparatus comprises a scanner body portion having an internal receptacle within a scan head portion thereof. A scanning control unit is disposed within the body portion separate from the receptacle and has an electrical connection that extends through the body portion to the receptacle. A removable optical module is adapted to engage the receptacle and be connected electrically to the scanning control unit through the electrical connection. The module includes an optical sensor adapted to receive light reflected from the bar code symbology through an opening through the body portion and convert the light into data representative of the symbology. The data is thereby provided to the scanning control unit. The optical sensor may comprise either a one-dimensional charge-coupled device, a two-dimensional charge-coupled device, an articulated laser, or a light emitting diode.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to Japanese Patent Application No. 2007-051839, filed Mar. 1, 2007, the disclosure of which is hereby incorporated herein by reference in its entirety.
BACKGROUND
The present disclosure relates to a sewing machine and a computer-readable recording medium storing a sewing machine control program. More specifically, it relates to a sewing machine that can be used for free-motion sewing and a computer-readable recording medium storing a sewing machine control program for a sewing machine that can be used for free-motion sewing.
Quilting is a conventional sewing method. In quilting, a batting is sandwiched between an outer material and a lining material, and then those materials may be sewn up along a stitch pattern, such as a straight line or a curve. In quilting, there is a case where stitches are formed while a user is freely moving a work cloth manually. Such sewing is referred to as free-motion sewing. In free-motion sewing, stitches may look unattractive if their stitch lengths are not uniform. Therefore, it is desirable to form stitches with a uniform stitch length as much as possible. However, it is difficult for a beginner, who is not skilled in sewing operations, to sew up a work cloth in such a manner as to form stitches with a substantially uniform stitch length while moving the work cloth in a desired direction. To solve this problem, a technique is disclosed in Japanese Patent Application Laid-Open Publication No. 2002-292175 in which driving of a sewing machine is controlled in such a manner as to form stitches with a uniform stitch length by obtaining a movement distance of a work cloth for each stitch, so that the sewing speed may be changed in accordance with the obtained movement distance.
In some cases, a stippling stitch is used in free-motion sewing. A stippling stitch should be disposed evenly within a predetermined region so that a user may enjoy the resulting beautiful design (see FIG. 21 ). In the stippling stitch, a uniform stitch length is not sufficient to obtain a beautiful result. Like stitch 902 in a predetermined region 901 shown in FIG. 21 , a beautiful stippling stitch should create a smooth curve that is disposed within the region 901 in a well-balanced and even manner. The stitch line should not overlap itself, nor should it come too close to other parts of the stitch line.
In a case where a user unskilled in the sewing operation sews the stippling stitch in the course of free-motion sewing with a sewing machine that employs the aforementioned conventional technique, the user can perform sewing in such a manner as to form stitches with a uniform stitch length. However, the user may still find it difficult to perform sewing while taking care not to form a stitch line with an overlapping part, and may even fail to do so. In such a case, the user may be involved in a troublesome task, because he must stop sewing, cut off a thread, remove the failed stitches, and then restart sewing.
SUMMARY
Various exemplary embodiments of the general principles described herein provide a sewing machine and sewing machine control program recorded in a computer-readable recording medium that detects a likelihood of stitches overlapping with each other in free motion sewing in which a user performs sewing as he/she manually moves a piece of work cloth.
Exemplary embodiments provide a sewing machine that sews a work cloth being moved by a user. The sewing machine includes a detection device that detects the work cloth, a movement calculation device that calculates a direction and a distance of movement of the work cloth as movement data when the work cloth is detected by the detection device, the movement being determined based on the location where the work cloth was previously detected by the detection device, and the movement data being in the form of two-dimensional coordinate data, a movement data storage device that stores the movement data calculated by the movement calculation device, a movement data creation device that causes the detection device to detect the work cloth for each stitch formed in sewing the work cloth, thereby causing the movement calculation device to calculate the movement data, and that stores the movement data calculated by the movement calculation device into the movement data storage device, a line segment specification device that specifies a line segment as a specified line segment based on the movement data stored in the movement data storage device, a determination device that determines whether a stitch to be formed next may overlap with an already formed stitch when the work cloth is detected by the detection device in a state where a sewing needle is above the work cloth, based on whether a line segment interconnecting a first position and a second position overlaps with the specified line segment or whether the specified line segment exists within a predetermined distance from the first position or the second position, the first position being a position on the work cloth below the sewing needle, and the second position being a most recent needle drop position, and an error control device that performs an error correction operation if it is determined by the determination device that the stitch to be formed next may overlap with the already formed stitch.
Exemplary embodiments also provide a sewing machine that sews a work cloth being moved by a user, the sewing machine including a detection device that detects a stitch formed on the work cloth, a determination device that determines whether a stitch to be formed next will overlap with an already formed stitch, based on whether the stitch detected by the detection device exists within a predetermined range determined on the basis of a first position or whether a line segment interconnecting the first position and a second position overlaps with the stitch detected by the detection device, the first position being a position on the work cloth below a sewing needle when the stitch, is detected by the detection device in a state where the sewing needle is above the work cloth, the second position being a most recent needle drop position, and an error control device that performs an error correction operation if it is determined by the determination device that the stitch to be formed next will overlap with the already formed stitch.
Exemplary embodiments further provide a computer-readable recording medium storing a sewing machine control program for a sewing machine that sews a work cloth being moved by a user. The program includes instructions for detecting the work cloth, instructions for calculating a direction and a distance of movement of the work cloth as calculated movement data each time the work cloth is detected, the movement being determined based on a location where the work cloth was previously detected, and the movement data being in the form of two-dimensional coordinate data, instructions for storing the calculated movement data as stored movement data each time the movement data is calculated, instructions for specifying a line segment as a specified line segment based on the stored movement data, instructions for determining whether a stitch to be formed next will overlap with an already formed stitch when the work cloth is detected in a state where a sewing needle is above the work cloth, based on whether a line segment interconnecting a first position and a second position overlaps with the specified line segment or whether the specified line segment exists within a predetermined distance from the first position or the second position, the first position being a position on the work cloth below the sewing needle, and the second position being a most recent needle drop position, and instructions for performing an error correction operation if it is determined that the stitch that is to be formed next will overlap with the already formed stitch.
Exemplary embodiments further provide a computer-readable recording medium storing a sewing machine control program for a sewing machine that sews a work cloth being moved by a user, the program including instructions for detecting a stitch formed on the work cloth, instructions for determining whether a stitch to be formed next will overlap with an already formed stitch, based on whether the detected stitch exists within a predetermined range determined on the basis of a first position or whether a line segment interconnecting the first position and a second position overlaps with the detected stitch, the first position being a position on the work cloth below a sewing needle when the stitch is detected in a state where the sewing needle is above the work cloth, the second position being a most recent needle drop position, and instructions for performing an error correction operation if it is determined that the stitch to be formed next will overlap with the already formed stitch.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the present disclosure will be described below in detail with reference to the accompanying drawings in which:
FIG. 1 is an overall perspective view of a sewing machine according to a first embodiment;
FIG. 2 is a perspective view showing a needle bar up-and-down movement mechanism and a needle bar releasing mechanism in the sewing machine of FIG. 1 ;
FIG. 3 is an elevational view of major components showing the needle bar up-and-down movement mechanism and the needle bar releasing mechanism in the sewing machine of FIG. 1 ;
FIG. 4 is an explanatory illustration showing an operation of the needle bar releasing mechanism to release a needle bar;
FIG. 5 is an explanatory illustration showing another operation of the needle bar releasing mechanism to release a needle bar;
FIG. 6 is an explanatory illustration showing a further operation of the needle bar releasing mechanism to release a needle bar;
FIG. 7 is an explanatory illustration showing an additional operation of the needle bar releasing mechanism to release a needle bar;
FIG. 8 is a side view of major components showing a sewing needle, a presser foot, and an image sensor;
FIG. 9 is a block diagram showing an electrical configuration of the sewing machine;
FIG. 10 is a conceptual diagram showing storage areas provided in RAM;
FIG. 11 is a table showing the configuration of a coordinate storage area in the RAM;
FIG. 12 is a flowchart of main processing showing the operations of the sewing machine;
FIG. 13 is an explanatory illustration showing a situation where a new stitch intersects with an already formed stitch;
FIG. 14 is an explanatory illustration showing a situation where a new stitch is formed on an already formed stitch;
FIG. 15 is a flowchart of determination processing which is performed in the main processing of FIG. 12 ;
FIG. 16 is an explanatory illustration of a method of calculating a distance between a line segment (stitches) and a point (needle drop point);
FIG. 17 is an overall perspective view of the sewing machine according to a modification of the first embodiment;
FIG. 18 is a block diagram showing the electrical configuration of the sewing machine according to a second embodiment;
FIG. 19 is a conceptual diagram showing the configuration of the RAM according to the second embodiment;
FIG. 20 is a flowchart showing the operations of the sewing machine according to the second embodiment; and
FIG. 21 is an explanatory illustration showing one example of a shape of stitches formed by stippling stitching.
DETAILED DESCRIPTION
The following describes first and second embodiments of the present disclosure with reference to the drawings. First, the first embodiment is described below with reference to FIGS. 1-15 . The configuration of a sewing machine I in the first embodiment is described below with reference to FIGS. 1-11 .
The physical configuration of the sewing machine 1 in the present embodiment will be described below with reference to FIG. 1 . The sewing machine I has a sewing machine bed 2 that extends in the right and left directions, a pillar 3 that is erected upward at the right end of the sewing machine bed 2 , and an arm 4 that extends leftward from the upper end of the pillar 3 . The left end of the arm 4 is referred to as a head portion 5 . The pillar 3 has on a front surface thereof a liquid crystal display (LCD) 10 having a touch panel 16 on its surface. The LCD 10 displays entry keys and the like for entering a pattern to be sewn, sewing conditions, etc. The user can select a desired pattern to be sewn, desired sewing conditions and the like by touching the positions corresponding to those entry keys on the touch panel 16 . The sewing machine 1 includes a sewing machine motor 79 (see FIG. 9 ), a drive shaft 11 (see FIG. 2 ), a needle bar 6 (see FIG. 3 ), a needle bar up-and-down movement mechanism 22 (see FIG. 2 ), a needle bar swinging mechanism 26 (see FIG. 3 ), and a needle bar releasing mechanism 25 (see FIG. 3 ). A sewing needle 7 (see FIG. 2 ) is attached to the lower end of the needle bar 6 . The needle bar up-and-down movement mechanism 22 is configured to raise and lower the needle bar 6 . The needle bar swinging mechanism 26 is configured to swing the needle bar 6 in the right and left direction. The needle bar releasing mechanism 25 is configured to release the needle bar 6 from the driving force of the sewing machine motor 79 .
The sewing machine bed 2 has a needle plate 80 disposed on an upper surface thereof. The sewing machine bed 2 includes a feed dog back-and-forth movement mechanism (not shown), a feed dog up-and-down movement mechanism (not shown), a feed adjustment pulse motor 78 (see FIG. 9 ), and a shuttle mechanism (not shown). The feed dog back-and-forth movement mechanism and the feed dog up-and-down movement mechanism are configured to drive a feed dog (not shown). The feed adjustment pulse motor 78 adjusts a feed distance by which a work cloth is fed by the feed dog. The shuttle mechanism houses a bobbin with a wound bobbin thread.
The head portion 5 has on a front surface thereof a sewing start switch 81 and a sewing stop switch 82 . The sewing start switch 81 is used to start sewing by starting the drive of the sewing machine motor 79 . The sewing stop switch 82 is used to stop sewing by stopping the driving of the sewing machine motor 79 . The sewing machine 1 has on a right side surface thereof a pulley (not shown) with which the drive shaft 11 is rotated by hand to move the needle bar up and down.
Next, the needle bar up-and-down movement mechanism 22 will be described below with reference to FIGS. 2-7 . As shown in FIGS. 2 and 3 , the needle bar 6 is slidably supported by an upper support portion 341 and a lower support portion 342 of a needle bar support 34 in such a manner that the needle bar 6 can move up and down. At a position along the needle bar 6 , a needle bar pawl support 30 (see FIG. 3 ) is fixed. The base end (upper end) of a needle bar pawl body 31 is pivotally supported by a pin 301 (see FIG. 6 ) in such a manner that the needle bar pawl body 31 is pivotally movable (see FIGS. 6 and 7 ). Below the needle bar pawl support 30 , a needle bar guide bracket 32 is connected to the needle bar 6 in such a manner that the needle bar guide bracket 32 can move up and down with respect to the needle bar 6 .
A thread take-up crank 27 is fitted to the end of the drive shaft 11 , and a needle bar crank rod 29 is coupled via a crank pin 28 which projects laterally from the thread take-up crank 27 . A boss 291 of the needle bar crank rod 29 and a shaft 322 which protrudes from the needle bar guide bracket 32 , are coupled in such a manner that the boss 291 can be rotated with respect to the shaft 322 . As shown in FIG. 6 , an engagement pawl portion 312 formed at the end (lower end) of the needle bar pawl body 31 can be engaged with and disengaged from a concaved locking portion 321 formed in the needle bar guide bracket 32 . Further, a torsion spring (not shown) is connected to the base end of the needle bar pawl body 31 , so that its spring force acts to hold the engagement pawl portion 312 and the locking portion 321 in an engaged state. If the drive shaft 11 is rotated by the driving of the sewing machine motor 79 while the engagement pawl portion 312 is engaged with the locking portion 321 as shown in FIG. 6 , the rotation of the drive shaft 11 is transmitted as up-and-down movement to the needle bar guide bracket 32 via the thread take-up crank 27 and the needle bar crank rod 29 . The up-and-down movement of the needle bar guide bracket 32 is transmitted via the needle bar pawl body 31 and the needle bar pawl support 30 to move the needle bar 6 up and down. A thread take-up lever (not shown) coupled to the thread take-up crank 27 moves up and down in conjunction with the rotation of the drive shaft 11 .
The needle bar swinging mechanism 26 is described below. The needle bar support 34 is hung and supported at its upper end 343 by a support shaft 35 that is fixed to a frame (not shown) of the sewing machine 1 so that the needle bar support 34 can be moved rotationally. Further, the lower end of the needle bar support 34 is urged in an arrow A direction by a spring (not shown). As shown in FIG. 3 , the needle bar swinging lever 36 (not shown in FIG. 2 ) is axially supported by a support shaft 361 that is fixed to the frame of the sewing machine 1 . The lower end of 362 of the needle bar swinging lever 36 is in contact with the side surface of the lower end 344 of the needle bar support 34 .
As shown in FIG. 2 , a needle bar swinging-and-releasing pulse motor 43 (hereinafter simply referred to as pulse motor 43 ) is fixed to the frame of the sewing machine 1 . A cam body 37 , which includes a needle bar swinging cam portion 371 and a needle bar releasing cam portion 372 , is fixed to the rotary shaft of the pulse motor 43 in such a manner as to rotate integrally with the rotary shaft. As shown in FIG. 3 , the needle bar swinging cam portion 371 of the cam body 37 contacts a contacting portion 363 connected at the upper end of the needle bar swinging lever 36 . When the pulse motor 43 operates to rotate the needle bar swinging cam portion 371 in an arrow E direction, the contacting portion 363 of the needle bar swinging lever 36 is pressed by the needle bar swinging cam portion 371 and moved rotationally in an arrow C direction. As a result, the lower end 344 of the needle bar support 34 is pressed in an arrow B direction against the biasing force of the spring. Conversely, when the needle bar swinging cam portion 371 is rotated in an arrow F direction in FIG. 3 , the lower end 344 of the needle bar support 34 is moved in an arrow A direction.
Next, the configuration of the needle bar releasing mechanism 25 is described below. As shown in FIGS. 2 and 3 , a support shaft 40 and the needle bar 6 are supported on the needle bar support 34 , in parallel. A releasing lever 41 is supported by the support shaft 40 so that the releasing lever 41 can be moved rotationally. A flared portion 411 formed at one end of the releasing lever 41 can contact an overhang portion 311 of the needle bar pawl body 31 (see FIG. 4 ). Further, a pin-like cam follower 412 that protrudes downward from the other end of the releasing lever 41 can contact the needle bar releasing cam portion 372 of the cam body 37 (see FIG. 4 ).
A coil portion of a torsion coil spring 42 is supported around the support shaft 40 . A fixing end extending from the coil portion of the torsion coil spring 42 is fixed to the flared portion 411 of the releasing lever 41 to urge the releasing lever 41 in a direction in which the cam follower 412 can contact with the needle bar releasing cam portion 372 . Therefore, when the cam body 37 is rotated by the pulse motor 43 , the needle bar releasing cam portion 372 contacts the cam follower 412 so that the releasing lever 41 may be moved clockwise around the support shaft 40 against the biasing force of the torsion coil spring 42 (see FIGS. 4 and 5 ). Therefore, the flared portion 411 presses the overhang portion 311 of the needle bar pawl body 31 in the right-hand direction in FIGS. 4 and 5 . Consequently, the needle bar pawl body 31 is pivotally moved in a direction in which the engagement pawl portion 312 is disengaged from the locking portion 321 of the needle bar guide bracket 32 (see FIGS. 6 and 7 ). As such, the needle bar pawl support 30 and the needle bar guide bracket 32 are released from a state (engaged state) where they are coupled in a driving relation to each other. The flared portion 411 of the releasing lever 41 extends over a range within which the needle bar pawl body 31 moves up and down when the needle bar pawl body 31 is engaged with the needle bar guide bracket 32 . It is thus possible to release the needle bar 6 irrespective of the vertical position of the needle bar 6 .
Between the needle bar pawl support 30 and the upper end of the needle bar support 34 , a tension spring 38 is disposed to constantly urge the needle bar 6 upward. The tension spring 38 pulls the needle bar 6 up to a top dead center position if the needle bar pawl support 30 and the needle bar guide bracket 32 are released from the state in which they are coupled in a driving relation to each other, as shown in FIG. 7 . Thus, the needle bar 6 stays in a standby state at the top dead center position when the needle bar 6 is released.
On the other hand, if the cam follower 412 is separated from the needle bar releasing cam portion 372 by driving of the pulse motor 43 , the biasing force of the torsion coil spring 42 causes the flared portion 411 of the releasing lever 41 to move rotationally in such a direction as to be separated from the overhang portion 311 of the needle bar pawl body 31 . Accordingly, by a torsion spring (not shown), the engagement pawl portion 312 of the needle bar pawl body 31 is locked to the locking portion 321 of the needle bar guide bracket 32 , as shown in FIG. 6 . As a result, the engagement pawl portion 312 and the locking portion 321 are coupled in a driving relation to each other. This coupling operation is performed at the top dead center position of the needle bar 6 .
As described above, the needle bar releasing mechanism 25 and the needle bar swinging mechanism 26 are configured to be operated by the driving of the pulse motor 43 . The operations to release and swing the needle bar 6 can be controlled by causing a later-described CPU 61 to execute a program.
Next, an image sensor 50 disposed in the sewing machine 1 will be described below with reference to FIG. 8 . The image sensor 50 includes a CCD camera and a control circuit, and captures an image with the CCD camera at predetermined lapses of time. The control circuit compares the most recently taken image and a currently taken image to pick up a portion commonly included in both images, and then provides values that represent a direction and a distance of the movement of the target based on a range of the commonly included portion and its position in the images. In the present embodiment, as shown in FIG. 8 , a frame (not shown) of the sewing machine 1 is fitted with a support frame 51 . The image sensor 50 is attached to the support frame 51 at a position where the image sensor 50 can capture an image of an area including a needle drop point of the sewing needle 7 and its vicinity. The needle drop point herein refers to a point at which a work cloth is stuck through by the sewing needle 7 attached to the needle bar 6 when the needle bar 6 is moved downward by the needle bar up-and-down movement mechanism 22 (see FIG. 1 ). A presser foot 47 , which holds down the work cloth, is attached to a presser holder 46 , which is fixed to the lower end of a presser bar 45 . The presser foot 47 and the presser holder 46 are made of a transparent resin so that images of stitches can be taken through them.
Next, the electrical configuration of the sewing machine 1 is described below with reference to FIG. 9 . As shown in FIG. 9 , a body 60 of the sewing machine 1 includes a CPU 61 , a ROM 62 , a RAM 63 , an EEPROM 64 , a card slot 17 , an external access RAM 68 , an input interface 65 and an output interface 66 which are connected to each other by a bus 67 . A sewing start switch 81 , a sewing stop switch 82 , a touch panel 16 , a lower-needle-position sensor 89 , and the image sensor 50 are connected to the input interface 65 . Drive circuits 71 , 72 , 74 and 75 are connected to the output interface 66 . The drive circuit 71 drives the feed adjustment pulse motor 78 . The drive circuit 72 drives the sewing machine motor 79 , which is used to rotate the drive shaft 11 . The drive circuit 74 drives the pulse motor 43 , which is used to swing or release the needle bar 6 . The drive circuit 75 drives the LCD 10 .
The CPU 61 conducts main control over the sewing machine 1 , to perform a variety of computations and processing in accordance with a control program stored in a control program storage area of the ROM 62 , which is a read only memory device. The RAM 63 , which is a random access memory, is provided with various storage areas as required for storing the results of various computations by the CPU 61 . The sewing start switch 81 and the sewing stop switch 82 are button type switches. The lower-needle-position sensor 89 , which detects a rotation phase of the drive shaft 11 , is configured to output an ON signal when the needle bar 6 is lowered from a higher needle position down to a lower needle position as the drive shaft 11 revolves. The higher needle position herein refers to a position at which the tip of the sewing needle 7 is above the upper surface of the needle plate 80 , i.e., above the work cloth. The lower needle position herein refers to a position where the tip of the sewing needle 7 is below the upper surface of the needle plate 80 .
Next, storage areas in the RAM 63 are described below with reference to FIG. 10 . As shown in FIG. 10 , the RAM 63 has a stitch counter storage area 631 , a coordinate storage area 632 , and a movement amount storage area 633 . The RAM 63 also has additional storage areas other than those illustrated. The stitch counter storage area 631 stores a stitch counter that counts the number of stitches when the coordinates of a stitch are recorded. The coordinate storage area 632 stores the coordinates of a stitch. The movement amount storage area 633 stores a movement amount of a work cloth that is outputted by the image sensor 50 .
Next, the coordinate storage area 632 in the RAM 63 will be described below with reference to FIG. 11 . The coordinate storage area 632 stores coordinates array R, which is a two-dimensional array showing a trajectory-of stitches. The coordinates array R includes an x-coordinate and a y-coordinate. The subscript of the two-dimensional array begins with “0”. The n'th array is herein expressed as R n (X n , Y n ). This means that the n'th array has an x-coordinate of X n and a y-coordinate of Y n . Further, a point represented by the coordinates in the array R n is herein expressed as p n . In the 0'th array, a position of the work cloth before the start of sewing, i.e., (0, 0), is stored as a reference position. The first and subsequent arrays sequentially store the coordinates that represent the positions of needle drop points with respect to the reference position. Thus, the n'th array stores the coordinates of the n'th needle drop point.
Next, the operations of the sewing machine 1 will be described below with reference to FIG. 12 . Processing in FIG. 12 starts when the startup of sewing is instructed by the operation of the sewing start switch 81 . In this processing, position information of stitches is recorded as coordinate information. Then, it is continually monitored whether a stitch to be formed overlaps with an already formed stitch when the sewing needle 7 is at the higher needle position and is to be lowered down to form the stitch on a work cloth. If having determined that the'stitches would overlap, the needle bar 6 is released from the power of the sewing machine motor 79 (needle bar releasing) so that the sewing needle 7 does not operate, thus controlling the sewing machine 1 not to form stitches.
First, in step 1 (S 1 ) an initial value of 0 is stored in the stitch counter storage area 631 of the RAM 63 to initialize a stitch counter n. Then, in step 2 (S 2 ) the CPU 61 accesses the image sensor 50 . When accessed, the image sensor 50 captures an image at startup which serves as a reference. In step 3 (S 3 ) initial values for the coordinates array R n , i.e., (X 0 =0, Y 0 =0), are stored into the coordinates array R 0 . In step 4 (S 4 ) the sewing machine motor 79 starts revolving.
In step 5 (S 5 ) a determination is made as to whether the output of the lower-needle-position sensor 89 is an ON signal, which indicates that the sewing needle 7 is at the lower needle position. When the sewing needle 7 is at the lower needle position (YES at S 5 ), the sewing needle 7 pierces the work cloth so that the work cloth cannot be moved. Therefore, it is not necessary to detect a movement amount of the work cloth. Therefore, the determination is repeated at S 5 until the lower-needle-position sensor 89 outputs an OFF signal, which indicates that the sewing needle 7 is not at the lower needle position (NO at S 5 ).
When the lower-needle-position sensor 89 outputs an OFF signal to indicate that the sewing needle 7 is not at the lower needle position (NO at S 5 ), it means that the sewing needle 7 has been pulled out of the work cloth, and thus the work cloth can be moved. Therefore, a position at which the lowered sewing needle 7 is to pierce the work cloth next time becomes the ending point of the next stitch. The stitch counter n is incremented by “1” (S 6 ). More specifically, 1 is added to the initial value 0 so that the stitch counter n becomes 1. Then, in step 7 (S 7 ) coordinate values of the coordinates array R n−1 are stored in the coordinates array R n . More specifically, the values of R 0 (0, 0) are stored in R 1 .
In step 8 (S 8 ) a determination is made as to whether the output of the lower-needle-position sensor 89 is an ON signal, which indicates that the sewing needle 7 is at the lower needle position (S 8 ). When the output of the lower-needle-position sensor 89 is an OFF signal, which indicates that the sewing needle 7 is not at the lower needle position (NO at S 8 ), it means that the sewing needle 7 is not pierced into the work cloth, so the work cloth is still moving. Therefore, in step 9 (S 9 ) the CPU 11 accesses the image sensor 50 to acquire an amount of movement as measured from a position at the time of the previous access and stores the amount in the movement amount storage area 633 . The movement amounts in the x-direction and the y-direction acquired from the image sensor 50 are written as the X and Y coordinates, respectively. The movement amount acquired from the image sensor 50 is added to R n , and R n is updated in step 10 (S 10 ). Specifically, X n =X n +X and Y n =Y n +Y are obtained. The updated R n represents the current position of the sewing needle 7 .
In step 11 (S 11 ) a determination is made as to whether a stitch to be formed by interconnecting a point represented by R n and a point represented by R n−1 overlaps with any one of the stitches formed so far if the sewing needle 7 is currently pierced into the piece of work cloth. More specifically, determination is made as to whether a line segment P n−1 p n , which interconnects points p n−1 and p n , overlaps with any one of line segments p 0 p 1 , p 1 p 2 , . . . , and p n-2 p n−1 . The determination processing at S 11 will be described in detail later with reference to a flowchart in FIG. 15 . Then in step 12 (S 12 ) a determination is made as to whether it was determined that the stitches overlap with each other in the determination processing at S 11 . In this case, because n=1 and thus no stitch has been formed, there is no stitch to be compared. Consequently, it has been determined that there are no overlapping stitches in the determination processing at S 11 (NO at S 12 ). Thus, the process returns to S 8 .
When the output of the lower-needle-position sensor 89 is obtained as an ON signal, indicating that the sewing needle 7 is at the lower needle position through the repetitive performance of the processing of S 8 -S 12 (YES at S 8 ), the repetition of the processing of S 8 -S 12 is stopped and the process advances to step 13 (S 13 ). In other words, the updating of the coordinates array R n is ended when the sewing needle 7 is pierced into the work cloth and positioned at the lower needle position. Accordingly, the coordinates immediately before the sewing needle 7 is pierced into the work cloth are employed as the values of the coordinates array R n . Because the processing of S 8 -S 12 are continually repeated by the CPU 61 , there is no problem to employ those coordinates as those of a needle drop point when making determination of a stitch overlap.
At S 13 , a determination is made as to whether the sewing stop switch 82 is operated (S 13 ). If the sewing stop switch 82 is not operated (NO at S 13 ), the process returns to S 5 to wait until the sewing needle 7 is again moved from the lower needle position (YES at S 5 ). If an OFF signal is obtained as the output of the lower-needle-position sensor 89 , indicating that the sewing needle 7 is moved from the lower needle position (NO at S 5 ), the stitch counter n is incremented by 1 to provide a count of 2 (S 6 ). Then, the values of the coordinates array R n−1 are stored into the coordinates array R n (S 7 ). More specifically, the values of R 1 are stored in R 2 . The process then advances to S 8 . In such a manner, the processing of S 5 -S 13 is repeated.
When the processing of S 5 -S 12 is repeated and it is determined that the line segment p n−1 p n that interconnects points p n−1 and p n overlaps with any one of line segments p 0 p 1 , p 1 p 2 , . . . , and p n−2 p n−1 , that is, the stitches overlap if the sewing needle 7 is lowered from the current position to form a stitch (YES at S 12 ), an error correction operation is performed. In the error correction operation, at step 14 (S 14 ) the needle bar releasing mechanism 25 is operated to release the needle bar 6 from the power of the sewing machine motor 79 . More specifically, the pulse motor 43 is driven to rotate the cam body 37 . When the cam body 37 is rotated to be in a state as shown in FIG. 5 , the needle bar releasing cam portion 372 presses the cam follower 412 . Consequently, the releasing lever 41 moves clockwise as shown in FIG. 5 against the biasing force of the torsion coil spring 42 . As a result, the flared portion 411 of the releasing lever 41 pivotally moves the overhang portion 311 of the needle bar pawl body 31 upward to release the needle bar pawl support 30 and the needle bar guide bracket 32 from the state in which they are coupled in driving relation to each other. After the needle bar 6 is released, the sewing machine motor 79 is stopped in step 15 (S 15 ) and the processing ends. If the sewing stop switch 82 is operated (YES at S 13 ), the sewing machine motor 79 is stopped (S 15 ) and the processing is ended.
Now, determination processing on the stitch overlap at S 11 is described below with reference to FIGS. 13-15 . When stitches overlap, it means that one stitch and another stitch pass through the same point. There are two cases when stitches overlap. The first case is when two stitches intersect with each other (endpoints of two line segments are not on one straight line), as shown in FIG. 13 . The second case is when two stitches are oriented in the same direction (endpoints of two line segments are on one straight line), as shown in FIG. 14 . As mentioned above, the coordinates of the needle drop point p n are stored in the coordinates array R n in advance and are expressed as (x-coordinate, y-coordinate)=(X n , Y n ).
When the two line segments (a first line segment and a second line segment) intersect with each other, as in the first case, the following two conditions are satisfied at the same time. The first condition is that a straight line which includes the first line segment should intersect with the second line segment. The second condition is that a straight line which includes the second line segment should intersect with the first line segment. For example, the first line segment is a line segment that goes through the determination processing (a line segment interconnecting the new needle drop point p n and the previous needle drop point p n−1 ) and the second line segment is any one of the already formed line segments p 0 p 1 , p 1 p 2 , . . . , and p n-2 p n−1 .
For example, of the line segments shown in FIG. 13 , the coordinate arrays are stored as R 0 (0, 0), R 1 (20, 0), R 2 (39.9, 1.7), R 3 (58, 10.2), R 13 (56.6, −4.2), and R 14 (42.5, 10).
As shown in FIG. 15 , in the determination processing, at step 21 (S 21 ) the initial value 0 is stored as variable m used to specify the second line segment. Then, in step 22 (S 22 ) a determination is made as to whether the first condition is satisfied, that is, whether a straight line that includes the first line segment p n p n−1 intersects with the second line segment p m p m+1 , i.e., line segment p 0 p 1 . The straight line that includes the first line segment p n p n−1 is hereinafter referred to as a first straight line.
The equation for the first straight line can be expressed by (X n−1 −X n ) (y−Y n−1 )+(Y n−1 −Y n )(−x+X n−1 )=0. Coordinates of two needle drop points that form the second line segment are respectively substituted into the left side (X n−1 −X n )(y−Y n−1 )+(Y n−1 −Y n ) (−x+X n−1 ). A value obtained by substituting the coordinates of one of the two needle drop points that comes earlier in order is R 1 , and a value obtained by substituting the coordinates of the other needle drop point that comes later in order is R 2 . When the signs of those values are both negative, the two needle drop points that form the second line segment are present in a coordinate region below the first straight line. On the other hand, when the signs of those values are both positive, the two needle drop points that form the second line segment are present in a coordinate region above the first straight line. Therefore, if the sign of R 1 *R 2 is negative, the first straight line extends between the two needle drop points that form the second line segment. In other words, the first straight line and the second line segment intersect with each other.
In the example shown-in FIG. 13 , n=14. Therefore, R 1 can be calculated by substituting coordinates (X 0 , Y 0 ) of point p 0 into x and y in (X 13 −X 14 )(y−Y 13 )+(Y 13 −Y 14 ) (−x+X 13 ). R 2 can also be calculated by substituting coordinates (X 1 , Y 1 ) of point p 1 . Then, a determination is made as to whether the sign of R 1 *R 2 is negative. In the example shown in FIG. 13 , since the respective coordinates arrays are R 0 (0, 0), R 1 (20, 0), R 13 (56.6, −4.2), and R 14 (42.5, 10), R 1 =(56.6−42.5)(0−(−4.2))+(−4.2-10)(−0+56.6)=−744.5. Thus, the sign of R 1 is negative. Further, R 2 =(56.6−42.5)(0−(−4.2))+(−4.2−10) (−20+56.6)=−460.5. Thus, the sign of R 2 is also negative. Therefore, R 1 *R 2 takes on a positive value, and thus it is determined that the first straight line and the second line segment do not intersect with each other (NO at S 22 ). The process then advances to step 24 (S 24 ).
At S 24 , a determination is made as to whether the first and second line segments are on the same straight line and overlap with each other, i.e., whether they are in the exemplary state shown in FIG. 14 (S 24 ). If R 1 and R 2 used in the determination on an intersection at S 22 are both 0, the first and second line segments are on the same straight line. Therefore, a determination is made as to whether R 1 =R 2 =0 (S 24 ). If R 1 =R 2 =0 does not hold true (NO at S 24 ), the first and second line segments are not on the same straight line. Therefore, the process advances to step 26 (S 26 ), and 1 is added to variable m to make it 2, in order to specify the second line segment that goes through the determination processing next (S 26 ). Then, in step 27 (S 27 ) a determination is made as to whether the value of variable m is larger than n−2, i.e., whether the determination on intersection has been made on all the second line segments. In the example of FIG. 13 , n−2=12 and m=2, so that it is determined that determination on an intersection has not yet been made on all the second line segments (NO at S 27 ). The process then returns to S 22 .
If R 1 =R 2 =0, the first and second line segments are on the same straight line (YES at S 24 ). Further, in step 25 (S 25 ) a determination is made as to whether the two line segments overlap with each other. Specifically, a determination is made as to whether the x-coordinate X m of an endpoint p m of the second line segment p m p m+1 is present between the respective x-coordinates X n and X n−1 of the endpoints p n and p n−1 of the first line segment p n p n−1 (S 25 ). More specifically, a determination is made as to whether X n ≦X m ≦X n−1 or X n−1 ≦X m ≦X n . If X m is present between X n and X n−1 , the first and second line segments are on the-same straight line and overlap with each other (YES at S 25 ). Therefore, in step 29 (S 29 ) it is determined that the stitches overlap and the processing is ended.
On the other hand, if X m is not present between X n and X n−1 , the two line segments do not overlap with each other (NO at S 25 ). Therefore, the process advances to step 26 (S 26 ), and 1 is added to variable m to make it 2 in order to determine the next line segment (S 26 ). Then at step 27 (S 27 ) it is determined whether the determination of an intersection has been made on all the second line segments. If the determination has not been made on all of the second line segments (NO at S 27 ), the process returns to S 22 to determine whether the next second line segment intersects with the first straight line (S 22 ). The processing of S 22 -S 27 is then repeated.
In the example shown in FIG. 13 , when variable m=2, it is determined at S 22 that the second line segment intersects with the first straight line (YES at S 22 ). In this case, the target for the determination is the second line segment p 2 p 3 . Since the respective coordinates arrays are R 2 (39.9, 1.7) and R 3 (58, 10.2), R 1 =(56.6−42.5)(1.7−(−4.2))+(−4.2−10)(−39.9+56.6)=−153.95. Thus, the sign of R 1 is negative. Further, R 2 =(56.6−42.5)(10.2−(−4.2))+(−4.2−10)(−58+56.6)=222.92. Thus, the sign of R 2 is positive. Therefore, R 1 *R 2 takes on a negative value and it is thus determined that the second line segment intersects with the first straight line (YES at S 22 ). In this case, the first condition is satisfied.
Next, it is determined whether the second condition is satisfied. Specifically, in step 23 (S 23 ) a determination is made as to whether a straight line including the second line segment p m p m+1 intersects with the first line segment p n p n−1 . The straight line including the second line segment p m p m+1 is hereinafter referred to as a second straight line.
Like the first straight line, an equation for the second straight line can be expressed as (X m+1 −X m )(y−Y m+1 )+(Y m+1 −Y m )(−x+X m+1 )=0. The coordinates of two needle drop points p n and p n−1 that form the first line segment p n p n−1 are substituted into the left side (X m +1−X m )(y−Y m+1 )+(Y m+1 −Y m )(−x+X m+1 ). A value obtained by substituting the coordinates of the needle drop point p n−1 is R 3 , and a value obtained by substituting the coordinates of the needle drop point p n is R 4 . When the signs of those values are both negative, the two needle drop points that form the first line segment are present in a coordinate region below the second straight line. On the other hand, when the signs of those values are both positive, the two needle drop points are present in a coordinate region above the second straight line. Therefore, if the sign of R 3 *R 4 is negative, the second straight line extends between the two needle drop points that form the first line segment, i.e., the second straight line and the first line segment intersect with each other.
In the example shown in FIG. 13 , since R 3 =(39.9)(−4.2−1.7)+(1.7−10.2) (−56.6−39.9)=248.74, the sign of R 3 is positive. Further, since R 4 =(39.9)(10−1.7)+(1.7−10.2)(−42.5−39.9)=−128.13, the sign of R 4 is negative. Therefore, R 3 *R 4 takes on a negative value, and it is determined that the second straight line intersects with the first line segment (YES at S 23 ). In other words, the second condition also is satisfied. Accordingly, in step 29 (S 29 ) it is determined that the stitches overlap.
If having determined that the first line segment and the second straight line do not intersect with each other (NO at S 23 ), the process advances to S 26 , and 1 is added to variable m to make it 2 in order to make determination on the next second line segment (S 26 ). Then, determination is made as to whether the determination on intersection has been made on all the second line segments (S 27 ). If determination has not yet been made on all of the second line segments (NO at S 27 ), the process returns to S 22 to determine whether the next second line segment intersects with the first straight line (S 22 ).
If none of the second line segments pmpm+1 intersects with the first straight line and, further, they are not on the same straight line (NO at S 22 and NO at S 24 , NO at S 22 , YES at S 24 , NO at S 25 , and YES at S 27 ), in step 28 (S 28 ) it is determined that the stitches do not overlap. If it is determined that the second line segment p m p m+1 and the first straight line intersect with each other but there is no second line segment p m p m+1 to make the second straight line which intersects with the first line segment p n p n−1 (YES at S 22 , NO at S 23 and YES at S 27 ), it is also determined that the stitches do not overlap (S 28 ).
In such a manner, in the determination processing at S 11 ( FIG. 15 ) in the main processing shown in FIG. 12 , the coordinates array R stored in the coordinate storage area 632 is referenced, and it is determined whether a stitch to be formed by interconnecting a point indicated by R n−1 and a point where the sewing needle 7 is to be pierced into the work cloth at this point in time overlaps with any one of stitches formed so far.
As described above, in the sewing machine 1 of the first embodiment, the coordinates of the needle drop points are stored beforehand in the coordinates array R. Then, while the sewing needle 7 is not at the lower needle position, continual monitoring is made as to whether stitches overlap. More specifically, it is continually monitored to determine whether a line segment interconnects a position at which the sewing needle 7 is to be lowered from the current position and a position at which the sewing needle 7 is most recently pulled out from the work cloth (most recent needle drop point), that is, whether the line segment p n p n−1 , overlaps with any one of the line segments that indicate stitches formed so far (line segments p 0 p 1 , p 1 p 2 , . . . , and p n−2 p n−1 ). If it is determined that the line segments overlap with each other, the needle bar releasing mechanism 25 releases the needle bar 6 from power due to the driving of the sewing machine motor 79 , thereby operations of the sewing needle 7 are stopped.
Therefore, the stitches can be prevented from overlapping with each other. It is thus possible to avoid making a mistake of overlapping stitches when, for example, a stippling stitch is formed by free-motion sewing, for which overlapping stitches may be considered unattractive.
The sewing machine 1 in the above-described embodiment may be modified as follows. For example, in the first embodiment, a CCD camera is employed in the image sensor 50 . The image sensor 50 , however, only needs to be capable of detecting a movement distance and a movement direction of a work cloth. Optionally, the camera may be a CMOS camera.
In the above-described embodiment, a determination is made as to whether a stitch to be formed, which interconnects a point indicated by R n−1 and a point at which the sewing needle 7 is to be pierced into the work cloth from the current position, overlaps with any one of the stitches formed so far. Based on the determination, the stitches can be prevented from overlapping with each other (S 11 in FIG. 12 ). However, this determination may not include whether the stitches (line segments) overlap with each other. For example, it may be determined whether there is any stitch (line segment) among the stitches (line segments) formed so far that has a predetermined range within which the coordinates position p n of the sewing needle 7 is present. In this case, if a stitch already exists in the predetermined range when the sewing needle 7 is pierced into the work cloth, i.e., if a stitch exists in the vicinity of the needle drop point p n , the error correction operation (releasing of the needle bar 6 ) may be performed.
One example of the determination on whether there is a stitch in the predetermined range is described below with reference to FIG. 16 . In this example, a distance between line segment AB and point C, which is not present on line segment AB, as shown in FIG. 16 , is considered. A distance between point C and one of the points on line segment AB that is nearest to point C is taken as distance L. The relationships between line segment AB and point C are divided into three cases shown in FIG. 16 . In the first case, the intersection point T of line segment AB and a perpendicular line drawn from point C to straight line AB is on line segment AB (point C 2 and intersection point T 2 ). In the second case, intersection point T is not present on line segment AB, and is closer to point A than to point B (point C 1 and intersection T 1 ). In the third case, intersection point T is not present on line segment AB, and is closer to point B than to point A (point C 3 and intersection T 3 ).
As shown in FIG. 16 , in the first case where intersection point T 2 is on line segment AB, length L C2 of a perpendicular line drawn from point C 2 to straight line AB is taken as distance L between line segment AB and point C. In the second case where intersection point T 1 is not on line segment AB and is closer to point A, which is one of the endpoints of line segment AB, length L C1 of line segment A C1 interconnecting point C 1 and point A is taken as distance L between line segment AB and point C. In the third case where intersection point T 3 is not on line segment AB and closer to point B, which is the other endpoint of line segment AB, length L C3 of line segment B C3 interconnecting point C 3 and point B is taken as distance L between line segment AB and point C.
In the determination process, the position of intersection point T is first determined. An amount of change in x and an amount of change in y along line segment AB can be defined as dx=X B −X A and dy=Y B −Y A , respectively. Then, the coordinates of intersection T of straight line AB and the perpendicular line drawn from point C to straight line AB can be expressed as T(X A +dx*t, Y A +dy*t). In this case, if 0≦t≦1, intersection point T is present on line segment AB. If t<0, intersection T is present outside of point A of line segment AB along straight line AB. If 1<t, intersection T is present outside of point B of line segment AB along straight line AB.
Variable t can be obtained as follows. Since line segment TC and line segment AB are perpendicular to each other, the inner product of their vectors is 0. That is, (dx, dy)·(X A +dx*t−X C , Y A +dy*t−Y C )=0 is established. This equation may be rearranged as (dx 2 +dy 2 )t+dx(X A −X C )+dy(Y A −Y C )=0. Supposing that dx 2 +dy 2 =a and dx(X A −Y C )+dy(Y A −Y C )=b, the equations can be expressed as a*t+b=0, and t=−b/a can be obtained. The values of a and b are expressed by the coordinates of point A, B, and C and as such, can be calculated, referring to the coordinates of array R.
If t<0, point C has a position relationship of point C 1 shown in FIG. 16 . Accordingly, distance L between line segment AB and point C is distance L C1 between point A and point C 1 . Specifically, distance L C1 is a positive square root of (X A −X C ) 2 +(Y A −X C1 ) 2 . Further, if t>0, point C has a position relationship of point C 3 shown in FIG. 16 . Accordingly, distance L between line segment AB and point C is distance L C3 between point B and point C 3 . Specifically, distance L C3 is a positive square root of (X B −X C3 ) 2 +(Y B −Y C3 ) 2 .
Further, if 0≦t≦1, point C has a position relationship of point C 2 shown in FIG. 16 . Supposing that intersection point T 2 is at (X T2 , Y T2 ), distance L C2 is a positive square root of (X A −X T2 ) 2 +(Y A −Y T2 ) 2 . It should be noted that X T2 =X A +dx*t=X A +dx*(−b/a) and Y T2 =Y A +dy*t=Y A +dy*(−b/a). The values of a and b are expressed by the coordinates of point A, B, and C, and as such, can be calculated referencing the coordinates array R.
Thus, calculated distance L is compared with a preset reference distance. If distance L is not larger than the reference distance, it is determined that there is already a stitch in a predetermined range so the needle bar releasing processing is performed. As the reference distance, a predetermined value (e.g., 3 mm etc.) may be stored in advance. Further, the reference distance may be determined in accordance with a stitch length (pitch). For example, the reference distance may be the same as the stitch length, 1.5 times as long as the stitch length, or longer than the stitch length by 2 mm. The reference distance may be stored in the ROM 62 or the EEPROM 64 or written into the program. Further, a menu for setting a reference distance may be displayed on the LCD 10 so that the user can enter a numeral on the touch panel 16 or select one of several preset numerals. If the user is permitted to set the reference distance, the user can employ a desired distance. Therefore, the user can adjust the numeral by, for example, selecting a small value if stitch trajectories come close to each other, and may select a large value if stitch trajectories do not come close to each other.
Further, rather than determining whether there is any one such stitch among the stitches formed thus far where the coordinates position p n of the sewing needle 7 is present in the predetermined range, determination may be made as to whether the last needle drop point (coordinates position p n−1 ) is in the predetermined range.
Further, in the first embodiment, if stitches are expected to overlap with each other, the needle bar releasing mechanism 25 releases the needle bar 6 from driving power of the sewing machine motor 79 as an error correction operation, thereby stopping the operations of the sewing needle 7 . However, the error correction operation is not limited to releasing the needle bar 6 . For example, revolving of the sewing machine motor 79 may be stopped to stop the operations of the sewing needle 7 . In this case, even after the revolving of the sewing machine motor 79 is stopped, several stitches may be formed through inertia. Nevertheless, the sewing machine motor 79 will be stopped faster than in a case where the user operates the sewing stop switch 82 after the user finds a stitch overlap. Therefore, even if stitches overlap with each other, the number of the overlapping stitches may be reduced. Further, rather than stopping the revolving of the sewing machine motor 79 , the sewing machine motor 79 may be slowed down, i.e., the sewing speed may be decreased.
Further, the error correction operation may involve notification rather than stopping or slowing down the operations of the sewing needle 7 . As shown in FIG. 17 , an alarm lamp 83 may be provided to the sewing machine 100 , so that it would light up or blink if stitches are expected to overlap with each other. The alarm lamp 83 might be disposed in the vicinity of a position at which the sewing needle 7 is stuck into a work cloth (needle drop point). For example, the alarm lamp 83 may be disposed at the lower end portion of the front surface of the head 4 , as shown in FIG. 17 . The alarm lamp 83 may be connected to the output interface 66 so that it may light up in accordance with an instruction from the CPU 6 1 . Further, as shown in FIG. 17 , a speaker 84 may be fitted to the sewing machine 100 so as to produce an alarm sound or a reminder message. The speaker 84 may also be connected to the output interface 66 . Further, these notification operations may be combined with other error correction operations, such as stopping of the operations of the sewing needle 7 , slowing down of the sewing speed, or releasing of the needle bar 6 .
Next, a second embodiment will be described below with reference to FIGS. 17-21 . In the second embodiment, a sewing machine 100 includes a CCD camera 53 , which captures an image in the vicinity of a needle drop point. If there is a stitch in the image captured, it is determined that a stitch is already present near an expected sewing position, and so there is a possibility of stitch overlapping. In this case, a sewing machine motor 79 is stopped to stop the operations of a sewing needle 7 so that sewing is stopped. The physical configuration of the sewing machine 100 in the second embodiment is much the same as that of the sewing machine 1 in the first embodiment, and so the explanation is omitted here. In the first embodiment, the sewing machine 1 includes the image sensor 50 (see FIG: 8 ). In the second embodiment, as shown in FIG. 17 , the sewing machine 100 further includes a color sensor 52 that detects a thread color. The color sensor 52 is fitted into the spool housing 20 , to which a thread spool 21 used in sewing is attached.
Next, the electrical configuration of the sewing machine 100 is described below. The electrical configuration of the sewing machine 100 also is much the same as that of the sewing machine 1 in the first embodiment (see FIG. 9 ). In the sewing machine 1 , the CCD camera 53 is connected to the input interface 65 . In the sewing machine 100 , the color sensor 52 is also connected to the input interface 65 . The CCD camera 53 and the color sensor 52 capture images as required by the CPU 61 , and input thread color data detected from the captured image to the input interface 65 .
Now, storage areas provided in a RAM 63 are described below with reference to FIG. 19 . As shown in FIG. 19 , the RAM 63 has a thread color storage area 638 , an image storage area 639 , and a pixel information storage area 640 . The RAM 63 has other storage areas other than those shown in FIG. 19 . The thread color storage area 638 stores data of a thread color detected by the color sensor 52 . The image storage area 639 stores an image of a work cloth (hereinafter referred to as a work cloth image) taken by the CCD camera 53 . The pixel information storage area 640 stores information that indicates a pixel that is determined to have the same color as the thread color in the most recent two work cloth images (a current image and a last image). The information indicating the pixel is hereinafter referred to as stitch pixel information.
Next, the operations of the sewing machine 100 are described below with reference to FIG. 20 . Processing shown in FIG. 20 starts when a sewing start switch 81 is operated to instruct start-up of sewing. As shown in FIG. 20 , in step 41 (S 41 ) a thread color is detected (S 41 ). Specifically, data of the thread color detected by the color sensor 52 is stored as RGB-values in the thread color storage area 638 .
Subsequently, in step 42 (S 42 ) a sewing machine motor 79 starts revolving to begin sewing. Then, in step 43 (S 43 ) a determination is made as to whether a sewing stop switch 82 is operated. If the sewing stop switch 82 is not operated (NO at S 43 ), in step 44 (S 44 ) an image of the vicinity of the needle drop point is captured by the CCD camera 53 , and a work cloth image is stored in the image storage area 639 . Then, in step 45 (S 45 ) a determination is made as to whether there is a stitch in the work cloth image.
Specifically, the last stitch pixel information stored in the pixel information storage area 640 is updated by the current stitch pixel information. Then, RGB-values of each of the pixels of the work cloth image are compared with the RGB-values of the thread color stored in the thread color storage area 638 . If the respective RGB-values are in a predetermined allowable range, they are considered to agree with each other. For example, if the R-value of the thread color is 125 and the R-value of the pixel in the work cloth image is in the range of ±3, that is, between 122 and 128, it is determined that their respective R-values agree with each other. In such a manner, information that indicates that the pixels whose RGB-values are all determined to agree with those of the thread color is stored as the current stitch pixel information in the pixel information storage area 640 in the RAM 63 . If there are at least a predetermined number of the pixels that are stored in the pixel information storage area 640 as the number of those that agree with the thread color in RGB-values, it is determined that there is a stitch in the work cloth image. The predetermined number may be either a constant percentage (1%, 0.5%, etc.) of all the pixels in a work cloth image or a fixed value. The fixed value, if employed, may vary with the resolution of a work cloth image.
Even if there is a stitch, there is no problem if the stitch has been formed most recently. That is, if the work cloth image has at least the predetermined number of pixels having the same color as the thread color, determination is made as to whether the stitch has been formed most recently. This determination is made by comparing the last stitch pixel information and the current stitch pixel information with each other. If a ratio at which the pixels indicated by the last stitch pixel information and the pixels indicated by the current stitch pixel information agree in at least a predetermined percentage, it may be considered that images of the same stitch have been captured. Accordingly, the percentage at which the pixels agree is calculated and, if it is at least a predetermined value (e.g., 50%), the stitch that is present in the work cloth image has been formed most recently. In such a case, it is determined that there is no stitch in the work cloth image.
If it is determined at S 45 that there is a stitch in the work cloth image-(YES at S 45 ), the revolving of the sewing machine motor 79 is stopped to stop the operations of the sewing needle 7 , and sewing is stopped at step 46 (S 46 ). Then, the present processing is ended. If it is determined at S 45 that there is no stitch (NO at S 45 ), the process returns to S 43 and the processing of S 43 -S 45 is repeated. If the sewing stop switch 82 is operated during the processing (YES at S 43 ), the present processing is ended.
As described above, in the sewing machine 100 in the second embodiment, if a stitch exists in the vicinity of a needle drop point, revolving of the sewing machine motor 79 is stopped in the error correction operation. Even after the revolving of the sewing machine motor 79 is stopped, several stitches may be formed because the operations of the needle bar 6 do not stop immediately. Nevertheless, the sewing machine motor 79 will be stopped faster than in a case where the user operates the sewing stop switch 82 after the user finds a stitch overlap. Therefore, even if stitches overlap with each other, the number of the overlapping stitches may be reduced so that fewer stitches may need to be unraveled, thereby mitigating the job of unraveling by the user.
The sewing machine 100 in the second embodiment may be modified as follows. For example, in the second embodiment, the sewing machine motor 79 is stopped to stop sewing in an error correction operation. However, the error correction operation is not limited to stopping the sewing machine motor 79 . As in the first embodiment, the operations of the sewing needle 7 may be stopped by releasing the sewing needle 6 from driving power of the sewing machine motor 79 by using the needle bar releasing mechanism 25 . Other error correction operations such as those described in the first embodiment also may be employed.
In the present embodiment, a determination is made as to whether there is a stitch in a predetermined range of a work cloth. It may be determined whether the stitch overlaps with any one of already formed stitches. In this case, if a line segment interconnecting an ending point of a most-recently formed stitch and a needle drop point overlaps with a detected stitch, it may be determined that the stitches overlap.
In the second embodiment, the color sensor 52 is attached to the spool housing 20 . The attachment position, however, is not limited to this configuration. The attachment position may be anywhere, as long as it is possible to detect a thread set along a thread hooking path from the thread spool 21 to the sewing needle 7 . Further, instead of detecting a thread color by the color sensor 52 , the RGB-values of the thread colors of a plurality of thread kinds may be stored in advance in the EEPROM 64 or the ROM 62 in the sewing machine 100 . In such a case, the thread colors may be displayed on the LCD 10 and selected by the user via the touch panel 16 . When the LCD 10 is not colored, the color names and the thread part numbers may be displayed so that the user can select a desired thread color.
Further, in the second embodiment, a stitch is detected on the assumption that the entirety of a work cloth image taken by the CCD camera 53 is within a predetermined range. However, the predetermined range may not be the entirety of the work cloth image, but may be only a part of the work cloth. For example, it is possible to use only such part of an image taken by the CCD camera 53 as necessary to be in a needle traveling direction from a needle drop point. In such a case, the most-recently formed stitch will not be detected. Further, in the second embodiment, images are continually taken by the CCD camera 53 to determine whether there is a stitch. However, there cannot be an already formed stitch when sewing is started, so that the CCD camera may be set to capture nothing within a predetermined lapse of time after the startup of sewing. Further, rather than taking images continually, the images may be taken at every predetermined lapse of time (e.g., 0.2s) to determine whether there is a stitch. Further, the CCD camera 53 may be replaced by a CMOS camera.
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A sewing machine that sews a work cloth being moved by a user includes a detection device that detects the work cloth, a movement calculation device that calculates movement data of the work cloth, a movement data storage device that stores the movement data, a movement data creation device that causes the detection device and the movement calculation device to respectively detect the work cloth and calculate the movement data for each stitch, and that stores the movement data into the movement data storage device, a line segment specification device that specifies a line segment based on the movement data, a determination device that determines whether a stitch to be formed next will overlap with an already formed stitch corresponding to the specified line segment, and an error control device that performs an error correction operation based on a determination result.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to segmented drive shafts and more particularly to segmented drive shafts wherein the segments may be misaligned at more than six degrees.
2. Description of the Prior Art
Segmented drive shafts are used in many applications. An example is the drive roller system of a belt conveyor. Typically, torque has been transmitted to the individual segments of the drive shaft through a plurality of universal joints. While performing somewhat satisfactorily as the means of power transmission, the use of universal joints present certain problems. The motion transmitted through a series of universal joints connecting non-parallel shafts can fluctuate widely and the joints are necessarily exposed and therefore are subject to dust contamination and corrosion. While these problems have been recognized, it has heretofore been beyond the state of present technology to substitute a gear type coupling for the universal joints.
Accordingly, it is among the objects of the present invention to provide a segmented drive shaft in which the motion transmitted to the individual segments is substantially uniform and which has coupling elements which are longer lasting and more reliable.
SUMMARY OF THE INVENTION
These and other objects of the present invention are achieved by providing a segmented drive shaft, the first individual segment of which is driven by a powered prime mover. Each successive segment is driven through a gear type coupling. Inserted within adjacent ends of the individual segments is an alignment tube. The alignment tube is adapted to receive one end of the shaft of the coupling. However, torque is not transmitted by the alignment tube to the individual segments, but though the coupling shafts directly to the individual segments. The alignment tube reduces the angle of misalignment of the shafts of the gear coupling. The present invention provides an improved segmented drive shaft which is more economical and reliable than the prior art shafts. The foregoing will more fully appear in the following detailed description of the specification when read in conjunction with the accompanying drawing FIGURE.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is an elevational view partly in section of the segmented drive shaft of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the FIGURE, a segmented drive shaft generally designated 10 has a roller 12 driven at A by a powered prime mover, not shown. The drive shaft is comprised of a series of driven roll segments 14 and 16. The number of driven rolls forms no part of the present invention and the number of such and the length of each is a matter of application of the drive shaft. Roll 12 and driven roll 14 and 16 can be made of any suitable material such as a high carbon steel. Intermediate the length of roller 12 a sleeve 18 is formed for coupling 20. Sleeve 18 has an internal axial bore 22, the inner surface 24 of which is formed into a plurality of involatile straight conventional gear teeth 24. Coupling 20 includes a shaft 26 having keyed in a conventional manner at the ends thereof hubs 28. Formed on the outer surface of hub 28 are a plurality of conventional curved gear teeth 30 which are adapted to mesh and coact with teeth 24. Flange 32 of sleeve 18 includes a conventional shaft seal 34 to maintain the lubricant within cavity 22 of the coupling.
Inserted within the adjacent ends of rolls 12 and 14 is an alignment tube 36. Alignment tube 36 is in supporting engagement with rolls 14 and 16 at points 38, 40, 42 and 44 and is adapted to rotate with rolls 14 and 16. Alignment tube 36 is made of a material similar to the rolls. Alignment tube 36 has an axial bore 46. The intermediate portion 48, which acts as the gear coupling sleeve of bore 46 is formed into sets of circumferentially spaced involute conventional flat gear teeth. Teeth 50 are adapted to mesh and coact with teeth 30 of hub 28. Flanges 54 and 56 have mounted therein shaft seals 56 which retain conventional packed lubricant within the defined area. It will be understood that the construction tube of the intermediate sections 60 of roll 14 and 62 of alignment tube 64 are constructed and function identically to that described for roll 12 and alignment tube 36. The intermediate section 60 which serves in the manner of sleeve 18 of roll 14 has a pair of circumferentially spaced flat gear teeth to mesh and coact with the gear teeth 32 of the hub 30 of shafts 26, the construction of which is described above. It is understood by those skilled in the art that if roll 12 were connected to the powered prime mover by means of a gear coupling, its construction would be identical to that of roll 14.
In operation, it is seen that the torque provided by the prime mover is transmitted from adjacent roll to adjacent roll by means of shafts 26 of the gear type coupling. While I have described a certain preferred embodiment of my invention, it will be understood it may be otherwise embodied within the scope of the following claims.
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Disclosed is an improved segmented driving shaft in which the torque is transmitted from roll segment to roll segment through flexible gear-type couplings. The shaft includes a plurality of alignment tubes which reduces the angle of misalignment of the gear-type couplings.
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RELATED APPLICATION
This application claims the benefit of priority of U.S. provisional application 60/806,557, filed Jul. 5, 2006, the entire contents of which are incorporated herein by this reference.
FIELD OF THE INVENTION
This invention relates to boat fenders, and more particularly, to an adjustable boat fender suspender configured for engagement by a conventional rod holder.
BACKGROUND
Fenders are widely used to protect boat hulls from physical damage by providing a durable cushion between the hull and another structure, such as a dock. Conventional fenders are typically comprised of an elongated body coupled to a tether. The body is typically a cylindrical structure comprised of an inflatable cushioning bladder, a closed cell foam cushion, a high density foam cushion, a combination of any of the foregoing, or some other form of shock absorbing structure. Typically an eyelet is formed at an end of the body for attaching it to one end of a tether, such as a nylon mooring line. In use, the other end of the tether is generally secured to a cleat mount or rail of a boat and the fender is suspended alongside areas of the hull likely to otherwise come in contact with a dock. When a fender is not in use, it is typically removed from the rail or cleat stored away in a locker or on a rack.
The tasks of tying, untying, and adjusting the length of rope is tedious and conducive to error. If a fender is suspended either too high or too low it may not protect the hull. If the rope is too long, the excess rope may lay onto the deck, presenting a tripping hazard. Even when boat fenders are removed for storage in lockers, or fender racks, the rope used for attaching the fenders to the rail or cleat may be difficult to gather and neatly store without tangling.
The invention is directed to overcoming one or more of the problems and solving one or more of the needs as set forth above.
SUMMARY OF THE INVENTION
To solve one or more of the problems set forth above, in an exemplary implementation of the invention, a boat fender system is provided. The system is configured for suspending a boat fender from a conventional rod holder. The system includes a handle configured for engagement by a rod holder. A boat fender is coupled to the handle by a tether. The tether has a length sufficient to allow the fender to hang from the handle to a desired location. The length may be fixed or adjustable. A compartment in the handle stores excess and unused portions of the tether.
In an exemplary embodiment, a boat fender suspender according to principles of the invention is configured for engagement by a conventional rod holder on a boat. The suspender includes a handle configured for engagement by a rod holder. A tether has a proximal end attached to the handle and distal end adapted for attachment to a boat fender. The tether has a length to allow the fender to hang from the handle to a desired location alongside a boat. The tether may be an adjustable length tether, meaning various lengths of the tether can be extended from the handle. The elongated hollow tubular handle body may be buoyant. A boat fender may be rotatbly attached to the distal end of the tether.
The handle may include an elongated hollow tubular handle body. A compartment within the hollow tubular handle body contains the tether. The tether may be coiled within the compartment for storage. A first end cap may seal the proximal end of the handle body. A second cap with a central aperture may seal the distal end of handle body. Optionally, a third cap with an ecentric aperture is threadedly engaged by the second cap and the tether passes through the eccenbtric aperture and the central aperture.
In another embodiment, the second cap includes a slot and contains a spring clip. The spring clip has a pair of arms extending through the slot. The spring clip also has a coil with a contracted diameter less than a diameter of the tether.
In yet another embodiment, a ferrule is disposed between the handle body and the second cap. The ferrule is configured to be compressed by the second cap. The tether passes through the ferrule and the second aperture.
In another embodiment, the hollow tubular handle body includes an additive, such as a photochromic additive in an amount effective to cause a visible change in color when the hollow tubular handle body reaches a predetermined temperature. As an alternative, the hollow tubular handle body may include a thermochromic additive in an amount effective to cause a visible change in color when the hollow tubular handle body reaches a determined temperature. As another alternative, the hollow tubular handle body includes a phosphorescent additive in an amount effective to absorb light energy and continue to release that energy as visible light in darkened conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other aspects, objects, features and advantages of the invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where:
FIG. 1 provides a plan view of an exemplary fender suitable for suspension from a rod holder with an adjustable length rope in accordance with the principles of the invention;
FIG. 2 provides a perspective view of another exemplary fender and washer suitable for suspension from a rod holder with an adjustable length rope in accordance with principles of the invention;
FIG. 3 conceptually illustrates an exemplary adjustable handle with an adjustable length rope for suspending a boat fender from a rod holder in accordance with principles of the invention; and
FIG. 4 conceptually illustrates an exemplary adjustable handle with an adjustable length rope for suspending a boat fender from a rod holder in accordance with principles of the invention;
FIG. 5 conceptually illustrates an exemplary adjustable handle and a rod holder for a boat fender suspended from a rod holder and having an adjustable length rope in accordance with principles of the invention; and
FIG. 6 conceptually illustrates an exemplary adjustable handle and a boat fender suspended from the handle and having an adjustable length rope in accordance with principles of the invention; and
FIG. 7 conceptually illustrates an exemplary adjustable handle with an adjustable length rope and a spring clamp for suspending a boat fender from a rod holder in accordance with principles of the invention; and
FIG. 8 conceptually illustrates an exemplary adjustable handle with an adjustable length rope and a compression fitting for suspending a boat fender from a rod holder in accordance with principles of the invention; and
FIG. 9 conceptually illustrates an exemplary adjustable handle with an adjustable length rope suspending a boat fender from a rod holder of a boat in accordance with principles of the invention.
Those skilled in the art will appreciate that the figures are not intended to be drawn to any particular scale; nor are the figures intended to illustrate every embodiment of the invention. The invention is not limited to the exemplary embodiments depicted in the figures or the types of fenders, shapes, relative sizes, ornamental aspects or proportions of components shown in the figures.
DETAILED DESCRIPTION
This invention relates to boat fenders, and more particularly, to a boat fender with and adjustable length rope and configured for suspending from conventional rod holders. For illustrative purposes the detail description that follows focuses primarily on an exemplary embodiment of the invention configured for suspending a fender as illustrated in FIG. 2 . However, the invention is not limited to event any particular fender, so long as the fender may be suspended from a tether. Instead, the principles of the invention may be applied to the fender illustrated in FIG. 1 , and to any other fender now known or hereafter developed that may be suspended alongside a vessel. The scope of the invention herein encompasses all such usages.
Referring now to FIG. 1 , a plan view of an exemplary fender suitable for suspension from a rod holder with an adjustable length rope in accordance with the principles of the invention is shown. The exemplary fender includes a cylindrical body 100 comprised of an inflatable cushioning bladder, a closed cell foam cushion, a high density foam cushion, a combination of any of the foregoing, or some other form of shock absorbing structure. Eyelets 105 , 110 are formed at the top and bottom ends of the body 100 , respectively, for attaching it to a tether, such as a nylon mooring line. However, the principles of the invention do not require any eyelets. Other means for attaching a tether to a fender may be applied within the scope of the invention.
Referring now to FIG. 2 , a perspective view of another exemplary fender and washer suitable for suspension from a rod holder with an adjustable length rope in accordance with principles of the invention is shown. The exemplary fender includes a cylindrical body 200 comprised of an inflatable cushioning bladder, a closed cell foam cushion, a high density foam cushion, a combination of any of the foregoing, or some other form of shock absorbing structure. A concentric channel extends from a top aperture 215 at the top end 205 of the fender to a bottom aperture 220 at the bottom end 210 of the fender. A free end of a tether, such as a nylon mooring line, may be passed through the channel 215 - 220 and a washer 230 at the bottom end 210 . The outer diameter of the washer is greater than the diameter of the bottom aperture, so that the washer cannot pass through the bottom aperture. The diameter of the aperture of the washer 230 is less than the diameter of the bottom aperture 220 and slightly larger than the diameter of the tether. The free end of the tether passing through the washer 230 may be knotted to prevent withdrawal through the washer 230 and channel 215 - 220 .
While, the principles of the invention do not require a fender with a central channel as conceptually illustrated in FIG. 2 , such a fender provides an important advantage. The central channel facilitates rolling motion (i.e., rotation of the fender about the axis concentric with the aperture) due to shear forces encountered during docking. Such rolling motion reduces the risks of abrasive damage to the hull and excessive twisting of the tether.
Referring now to FIGS. 3 and 4 , an exemplary adjustable handle for a boat fender in accordance with principles of the invention is shown. The handle includes an elongated hollow tubular handle body 300 . A compartment 400 within the handle body 300 is configured for containing excess and stored portions of rope (or other tether). Rope may be coiled within the compartment for neat compact storage without entanglement. A first end cap 310 seals the proximal end of the body 300 . A male threaded cap 305 with an eccentric aperture 317 is provided at the distal end of handle body 300 . A corresponding female threaded cap 320 with a concentric aperture 319 is also provided. The eccentric aperture 317 and the concentric aperture 319 each have a diameter that is slightly larger than the diameter of the rope 325 . When the female threaded cap 320 is secured to the male threaded cap 305 , the rope passing through the concentric aperture 319 and the eccentric aperture 317 becomes securely sandwiched between the female threaded cap and the male threaded cap 305 . When the female threaded cap 320 is loosened from the male threaded cap 305 , the rope passing through the concentric aperture 319 and the eccentric aperture 317 is released between the female threaded cap and the male threaded cap 305 and free to withdraw. The handle body 300 features a size and contour that comfortably and securely fits in a fishing pole holder.
Referring now to FIG. 5 , an exemplary adjustable handle and a rod holder in accordance with principles of the invention are shown. Fishing boats are often equipped with rod holders 500 along their port and starboard gunnels and across the transom top board 510 to thereby enable fishermen to use more than one fishing rod. The rod holders may be built into the structure, surface mounted, or attached using additional hardware. The handle body 300 of the exemplary fender holder is configured to be received by conventional rod holders 500 . As the handle 300 may readily be inserted into and removed from a rod holder 500 , the fender holder is easy to install and remove for storage. Additionally, being designed to support substantial loads, a rod holder has the physical integrity to adequately support a fender during normal usage conditions. Moreover, use of the rod holders allows the cleats to be used for other purposes such as mooring lines for securing a vessel to a dock.
Referring now to FIG. 6 , an exemplary adjustable handle and a boat fender suspended from the handle and having an adjustable length rope in accordance with principles of the invention is shown. The handle includes an elongated hollow tubular handle body 300 . A compartment 400 (shown in FIG. 4 ) within the handle body 300 is configured for containing excess and stored portions of rope (or other tether). Rope may be coiled within the compartment for neat compact storage without entanglement. A first end cap 310 seals the proximal end of the body 300 . A male threaded cap 305 with an eccentric aperture 317 is provided at the distal end of handle body 300 . A corresponding female threaded cap 320 with a concentric aperture 319 is also provided. The eccentric aperture 317 and the concentric aperture 319 each have a diameter that is slightly larger than the diameter of the rope 325 . When the female threaded cap 320 is secured to the male threaded cap 305 , the rope passing through the concentric aperture 319 and the eccentric aperture 317 becomes securely sandwiched between the female threaded cap and the male threaded cap 305 . When the female threaded cap 320 is loosened from the male threaded cap 305 , the rope 325 passing through the concentric aperture 319 and the eccentric aperture 317 is released between the female threaded cap and the male threaded cap 305 and free to withdraw. The exemplary fender includes a cylindrical body 200 comprised of an inflatable cushioning bladder, a closed cell foam cushion, a high density foam cushion, a combination of any of the foregoing, or some other form of shock absorbing structure. A concentric channel extends from a top aperture 215 at the top end 205 of the fender to a bottom aperture 220 at the bottom end 210 of the fender. A free end of the rope 325 is passed through the channel 215 - 220 and through an aperture of a washer 230 at the bottom end 210 . The outer diameter of the washer 230 is greater than the diameter of the bottom aperture 215 - 220 , so that the washer 230 cannot pass through the bottom aperture. The diameter of the aperture of the washer 230 is less than the diameter of the bottom aperture 220 and slightly larger than the diameter of the tether. The free end of the rope passing through the washer 230 may be knotted 600 to prevent withdrawal through the washer 230 and channel 215 - 220 . Thus, the weight of the fender rests upon the washer 230 .
To accommodate a long length of rope 325 , the handle body 300 may contain a shaft or spool 705 and means for rotation, such as a manually rotatable cap 3 10 . The rope 325 may be wound around the shaft 705 by rotating the cap 310 in a first direction. The rope 325 may be unwound and withdrawn from the handle body 300 by pulling it and/or rotating the end cap 310 in a direction opposite the first direction.
The handle body 300 may be comprised of various materials, such as metal and/or plastic. In an exemplary implementation, the handle body 300 is comprised of a rigid plastic or polymeric material, such as polyvinyl chloride (PVC), polyethylene, polypropylene, polystyrene, acrylics, cellulosics, acrylonitrile-butadiene-styrene terpolymers, urethanes, thermo-plastic resins, thermo-plastic elastomers (TPE), acetal resins, polyamides, polycarbonates and polyesters. While many other materials may be used alone or in combination with the aforementioned materials and/or other materials, without departing from the scope of the present invention, preferably the material is relatively inexpensive, easy to use in manufacturing operations and results in an aesthetically acceptable, durable, weather and salt water resistant product. The material may further include additives to provide desired properties such as desired colors, structural characteristics, glow-in-the dark properties and thermal reactivity (e.g., color changes according to heat).
By way of example and not limitation, the handle body 300 may optionally be formulated to change color when it reaches a predetermined or higher temperature. This can be accomplished by mixing a thermochromic additive to the base material in an amount that is sufficient to achieve a desired color changing range. As an example, a mixture of approximately 5% to 30% (pbw) of Matsui International Co., Inc.'s Chromicolor® concentrate may be introduced to the base material, to provide a plastic structure that visibly changes color at a determined elevated temperature, such as approximately 90 degrees Fahrenheit or higher.
Alternatively, a photochromic additive may be added to the base material in an amount that is effective to achieve a desired color change when the handle body 300 is exposed to certain lighting conditions. As an example, a mixture of approximately 5% to 35% (pbw) of Matsui International Co., Inc.'s Photopia® additive may be introduced to the base material, to provide a plastic structure that visibly changes color in the presence of sunlight or ultraviolet light.
As another alternative, phosphorescent polymer additives, such as aluminate based phosphors, may be added to adsorb light energy and continue to release that energy as visible light after the energy source is removed. Advantageously, such an embodiment provides a handle body 300 that is easy to locate in darkened conditions, making the device easy to spot even at nighttime.
The handle body 300 may be produced using any suitable manufacturing techniques known in the art for the chosen material, such as (for example) injection, compression, structural foam, blow, or transfer molding; polyurethane foam processing techniques; vacuum forming; and casting. Preferably, the manufacturing technique is suitable for mass production at relatively low cost per unit, and results in an aesthetically acceptable product with a consistent acceptable quality.
The exemplary embodiments described above include one exemplary mechanism for locking the rope at a desired length. Other locking means may be utilized within the scope of the invention. For example, the line may be cut to size and either knotted so that a knotted end within the handle cannot pass through a narrow aperture in cap 320 or attached to the interior structure of the handle. Still, other means for controlling the length of rope allowed to be withdrawn from the handle 300 may be utilized within the scope and spirit of the invention. Such other means may, for example, include spools, reels and other devices with locking mechanisms.
Illustratively, as shown in FIG. 7 , a spring clamp 710 may be provided to controllably grip and lock the rope at a desired length. A slot 725 in the cap allows exposure of the arms 715 of the spring clamp 710 . The diameter of the spring clamp coil 720 expands when the arms 715 are urged towards each other. When pressure is relieved from the arms 715 , the arms 715 return to their original position and spring clamp coil 720 contracts. The contracted coil 720 grips the engaged portion of the rope 325 .
As another example, as shown in FIG. 8 , a compression fitting assembly 800 may be provided to controllably grip and lock the rope 325 at a desired length. The compression fitting is composed of the cap 320 which serves as an outer “compression nut” and a ferrule 805 , i.e. a gripping band or ring. The rope 325 passes through the central aperture of the ferrule. When the cap 320 is tightened, it clamps-down on the ferrule 805 , compressing the ferrule 805 and causing it to tightly conform to the circumference of the rope 325 .
The ferrule may vary in shape and material according to the rope material. By way of example and not limitation, the ferrule may be comprised of a rubber, plastic or polymeric material, such as silicone, polyvinyl chloride (PVC), polyethylene, polypropylene, polystyrene, acrylics, cellulosics, acrylonitrile-butadiene-styrene terpolymers, urethanes, thermo-plastic resins, thermo-plastic elastomers (TPE), acetal resins, polyamides, polycarbonates, polyesters, polyisoprene, butyl rubber, halogenated butyl rubber, polybutadiene, styrene-butadiene rubber, nitrile rubber, hydrated nitrile rubber, chloroprene rubber, ethylene propylene rubber, ethylene propylene diene rubber, epichlorohydrin rubber, polyacrylic rubber, fluorosilicone rubber, fluoroelastomers, perfluoroelastomers, tetrafluoro ethylene/propylene rubbers, chlorosulfonated polyethylene, ethylene-vinyl acetate, thermoplastic elastomers and thermoplastic vulcanizates. While many other materials may be used alone or in combination with the aforementioned materials and/or other materials, without departing from the scope of the present invention, preferably the material is relatively inexpensive, easy to use in manufacturing operations and results in a durable, sea water resistant product.
Optionally, the handle body 300 includes a buoyant padding material such as Neoprene foam or other cushioning buoyant material. The buoyant padding material should have a thickness sufficient for providing general buoyancy to the device. As used herein, buoyancy refers to an upward force on the handle body 300 produced by surrounding fluid (i.e., water) in which it is fully or partially immersed. The net upward buoyancy force is equal to the magnitude of the weight of fluid displaced by the body. In an implementation where the buoyancy of the handle body 300 exceeds its weight, it will tend to rise and float. Thus, for example, if the handle body 300 falls into water, it will float rather than sink, making it easier to locate and retrieve.
Referring now to FIG. 9 , an exemplary adjustable handle 300 with an adjustable length rope 325 suspending a boat fender 200 from a rod holder of a boat 900 in accordance with principles of the invention is conceptually shown. While a pair of fenders 200 are suspended, any number may be used in connection with an equal number of rod holders or similar devices suitable for supporting a handle body 300 .
While an exemplary embodiment of the invention has been described, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. With respect to the above description then, it is to be realized that the optimum relationships for the components and steps of the invention, including variations in order, form, content, function and manner of operation, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. The above description and drawings are illustrative of modifications that can be made without departing from the present invention, the scope of which is to be limited only by the following claims. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents are intended to fall within the scope of the invention as claimed.
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A boat fender system is configured for suspending a boat fender from a conventional rod holder. The system includes a handle configured for engagement by a rod holder. A boat fender is coupled to the handle by a tether. The tether has a length to allow the fender to hang from the handle to a desired location. The length may be fixed or adjustable. A compartment in the handle stores excess and unused portions of the tether.
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BACKGROUND OF THE INVENTION
This is a continuation-in-part of Ser. No. 077,804 filed July 27, 1987, now U.S. Pat. No. 4,836,042 which is incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates to mechanisms to convert rotary motion to linear motion.
SETTING OF THE INVENTION
There is disclosed herein a system that includes a nut to convert rotary motion from a leadscrew to linear motion by way of a special threadform which utilizes high pressure air, oil, or some other fluid as an interface between the threads of the nut and the threads of the leadscrew whereby, among other things, mechanical contact between the threads of the nut and leadscrew is prevented by the existence of a high pressure fluid layer between the two which acts to damp out mechanical noise. The special threadforms of the leadscrew and the nut, when supplied with high pressure fluid, provide a mechanism for the nut to very efficiently convert rotary power input to the leadscrew to linear power. The use of a fluid as an interface between the threadforms eliminates friction and results in almost 100% power conversion efficiency. The high pressure fluid interface between the threadforms also acts to preload the nut threadform between the leadscrew threadform thereby eliminating backlash between the leadscrew and nut. The special thread design (i.e. the rectangular thread disclosed herein), furthermore, enables the nut to act as a coupling between itself (i.e. self-coupling herein) and a movable carriage such that only forces along an axis parallel to the axis of the leadscrew are transmitted from the nut to the carriage. A leadscrew should ideally be stiff only in the axial direction; the bearing carriage that the leadscrew moves should act to maintain the radial and angular position of the leadscrew nut. Hence, potential misalignment forces and moments, along and about the other two axes that are orthogonal to the leadscrew axis will not be generated or transmitted as a result of misalignment of the leadscrew axis with the axis of the movable carriage. This greatly decreases the amount of manufacturing cost required to manufacture a precision machine. A leadscrew with these properties would be known as one that is self coupling, because it does not need a separate machine element or expensive hand finishing operation to couple it to the machine.
Previous attempts at eliminating friction in leadscrews through the use of hydrostatic leadscrews have all overlooked the need to also eliminate coupling errors (Inazaki, Japanese patent 58-166,162; Ernst et al, U.S. Pat. No. 2,320,352; Erickson et al, U.S. Pat. No. 3,171,295; and Inazaki, Japanese patent 58-166,161). These past hydrostatic leadscrew development attempts were guided by conventional leadscrew design methods. These methods are based on the historical need for elastic averaging between the screw and nut threads to reduce lead errors and backlash. Elastic averaging requires the nut to firmly grip the shaft so the threadform of the nut elastically deforms to match that of the leadscrew. This has the effect of averaging out lead errors, but then rigidly couples the nut to the leadscrew. In the days prior to precision electronic linear motion sensors, counting the turns of a precision screw was the only way to measure linear motion, and thus using an elastically averaged screw was the only way to attain accurate linear motion; however, this method also generated forces and moments along and about the non axial directions when the leadscrew was not exactly parallel to and aligned with the carriage to which the leadscrew nut was bolted. These forces and moments cause motion errors in the carriage and hasten wear of the leadscrew. With modern sensors (e.g. a laser interferometer), the leadscrew need only provide high resolution backlash free motion. It is as if designers have been holding on too strongly to their historical roots, and as a result they did not realize that if they integrate the design of a linear sensor with a leadscrew, the former would take care of the measuring and the latter would only have to be made self-coupling, backlash free, and frictionless. The hydrostatic leadscrew disclosed herein meets these criteria.
Accordingly it is an objective of the present invention to provide a mechanism to convert rotary power from a shaft to linear power in a linearly movable carriage without power losses due to friction in the mechanism.
Another objective is to accomplish rotary to linear power transmission with mechanical motion smoothness and accuracy on the order of microinches or less while using components which themselves have only been manufactured with a tolerance on the order of hundreds of microinches.
Another objective is to accomplish rotary to linear power transmission with the axial stiffness of the mechanism equal to or greater than the axial stiffness of any other component in the system, such as the leadscrew shaft.
A further objective is to provide a mechanism to accomplish the preceding objectives while acting as its own coupling between the nut and movable carriage such that only forces along an axis parallel to the axis of the leadscrew are transmitted from the nut to the carriage, while potential misalignment forces and moments along and about the other two axes that are orthogonal to the leadscrew axis are not generated or transmitted as a result of misalignment of the leadscrew axis with the axis of the movable carriage.
These and still further objectives are addressed hereinafter.
SUMMARY OF THE INVENTION
The foregoing objectives are attained, generally, in a mechanism to convert rotary power from a leadscrew to linear motion by way of a special threadform which utilizes high pressure air, oil, or some other fluid as an interface between a special threadform of a leadscrew and the special threadform of an associated nut. The special threadforms when supplied with high pressure fluid and incorporated into the design of a leadscrew and nut provide a way for the nut to convert the rotary power of the leadscrew to linear power, for powering a linear movable slide, without losing any power in the form of friction between the threadforms of the leadscrew and the nut. The mechanism furthermore uses the high pressure fluid interface between the threadforms to preload the nut thereby eliminating backlash between the leadscrew and nut. The mechanism also acts as its own coupling between the nut and a linearly movable carriage such that only forces along an axis parallel to the axis of the leadscrew are transmitted from the nut to the carriage, while potential misalignment forces and moments, along and about the other two axes that are orthogonal to the leadscrew axis are not generated or transmitted as a result of misalignment of the leadscrew axis with the axis of the movable carriage.
In this system the leadscrew rotates about its axis to effect parallel linear movement therealong of the nut, the cooperative threadforms of the leadscrew and nut being shaped to provide for a small degree of pitch and yaw and relative radial movement of the nut out of parallelity with the leadscrew; a means is provided for continuously supplying pressurized fluid between the cooperative threads of the leadscrew and nut, and a means is provided for controlling the fluid pressure continuously, for example with an orifice or other means such as a constant flow device, to provide high axial stiffness with substantially zero stiffness in yaw, pitch, rotation and radial motion while inhibiting mechanical contact and eliminating friction between the cooperative threads, thereby to maintain the linear movement of the nut parallel to the leadscrew axis. Frictionless motion between surfaces is required to prevent wear and allow for very precise positioning. Hence the mechanism is self coupling. As mentioned before, others have invented leadscrews and nuts that use high pressure fluid to minimize friction; however no attempt has been made to design the threadform to achieve true hydrostatic support, while at the same time providing a means to provide high axial stiffness with effectrively zero stiffness in yaw, pitch, rotation and radial motion.
A pressurized fluid bearing is typically composed of two opposing bearings such that when a load is applied, the gap across one bearing decreases while the gap across the second bearing increases. The pressure in the bearing with the decreasing gap increases while the pressure in the bearing with the increasing gap decreases to create a pressure differential. The pressure differential acts to force the supported structure back in the direction of increasing gap. The orifices or other fluid flow control means prevent the pressurized fluid from escaping unrestricted through the side of the bearing with the increasing gap.
To date, no one has developed a self coupling frictionless leadscrew and nut combination. The principal problem has been in correctly identifying the problem of why certain error motions in machines exist, and then developing the correct threadform to provide high axial stiffness with substantially zero stiffness in yaw, pitch, rotation and radial motion, and a procedure to manufacture the threadform. This invention addresses each of these issues.
BRIEF CHARACTERIZATION OF THE DRAWING
The invention is described hereinafter with reference to the accompanying drawing in which:
FIG. 1 is a schematic cutaway view of a machine that utilizes a leadscrew and nut to move a linear slide to which a tool is attached for machining a part;
FIG. 2 is a cross section schematic showing a portion of special threadforms of both the leadscrew and the nut in FIG. 1 which allows air or some other fluid to be used as a very stiff interface between the threadforms;
FIG. 3 is a cross section of a self coupling nut blank prior to it being threaded over the leadscrew and epoxy poured into the space between the threads of the nut and leadscrew, and through the use of putty and mold release wax, obtaining proper radial and axial clearances and the helical grooves in the epoxy cast threads;
FIG. 4 is a cross section of the self coupling nut after the epoxy has been cast about its threads.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drawing shows a mechanism or system that is operative to convert rotary power from a leadscrew to linear motion of a nut by means of special threadforms which utilize high pressure air, oil, or some other fluid as an interface between the special threadforms of the leadscrew and the nut. As shown in FIG. 1, the mechanism would typically be used to operate a machine or system 4 which could be composed of a tail 6, a bed 22, a head 21, a headstock 10, a spindle 11 (that would have to be able to move along an axis orthogonal to that of a tool 13 in order to generate a curved surface as shown), a part 12 held to the spindle, a tool 13 held by a toolpost 14 that is anchored to a linearly movable carriage 15 that is supported by a linear bearing 16. A motor 5 turns a leadscrew 19 with the special threadform 24, as later discussed in detail. A nut 17 mates with the leadscrew 19 and converts rotary power to linear power to move the carriage 15 and the tool 13 for cutting a contour into the part 12, with very high efficiency and zero backlash or wear between the leadscrew 19 and the nut 17. The leadscrew 19 and mating aperture within the nut 17 are, of course, circular-cylindrical in shape and cross dimensions. In the leadscrew and nut system shown, rotation of the leadscrew about its axis effects parallel linear movement of the nut therealong with a very high effective axial stiffness, the cooperative threadforms of the leadscrew and nut being shaped to allow without resistance for small degrees of pitch, yaw, as well as small relative radial movement of the nut out of parallelity with the leadscrew. Hence the leadscrew and nut are self coupling.
To accomplish the conversion of power with high efficiency and zero backlash or wear between the nut 17 and the leadscrew 19, a special threadform is needed, as discussed herein. In the first case where many threads may be required, as shown in FIG. 2, an inner core 28A, containing the special threadform 28, is fastened to an outer core 30 by means of a bonding mechanism such as an adhesive 29 (or shrink fit techniques may be employed, or in some cases the geometry can be made from a solid piece). This threaded core can itself be made from a milling, turning, or grinding process used to make the leadscrew 19. The threadform of the nut 28 mates with the threadform 24 of the leadscrew 19 such that sufficient axial clearance 31 is provided between the nut and leadscrew threadforms to allow a cushion of high pressure air, oil, or some other fluid to act as an interface between them. The clearance 31 must also be sufficient to allow for rocking motion of the nut 17 about the Y and Z axes by an amount equal to the expected angular misalignment of the leadscrew 19 with the linearly movable carriage 15.
In addition, radial clearance 32 is provided between the threadform 28 of the nut 17 and the threadform 24 of the leadscrew 19 to allow for radial motion of the nut in the Y and Z directions by an amount equal to the expected lateral (radial) misalignment of the leadscrew 19 with the linearly movable carriage 15, and to allow high pressure fluid escaping from the clearances 31 between the nut and leadscrew threadforms to easily exhaust to the atmosphere.
The threadform 28 of the nut also contains shallow radially-elongate grooves 22A and 22B (shown greatly enlarged) to distribute and equalize the high pressure fluid along the length (i.e., radial dimension) of each respective side of the teeth of the nut threadform 28. These grooves are independent from each other and extend continuously in a helical fashion along the entire helix of each side of the nut's threadform 28, but are capped at the ends of the helix to prevent loss of the pressurized fluid. Orifices or other fluid flow control devices such as 23 (shown greatly enlarged) from fluid passages 26 are placed at intervals along the length of the grooves 22A and 22B to provide high pressure air along the entire helical length of the grooves and to the clearance 31 between the leadscrew and nut threadforms. The fluid supply holes, 26, extend radially inwardly from a larger reservoir 27 to intersect with the orifices and serve to supply high pressure fluid to them and hence to the grooves 22A and 22B. The radial holes 26 are drilled from outside the nut 17; press fit metal plugs 33 serve to plug the outside ends of the holes 26. High pressure fluid is supplied to the plenum 27 by a nozzle 20'. Radial exhaust holes such as 21 are drilled about the circumference of the nut 17 to help exhaust fluid in the radial clearance space 32 between the leadscrew and nut threadforms. For a single turn thread on the nut, typically as few as two fluid supply holes are needed, one for each side of the thread, and fluid exits out the ends of the nut so radial drain holes are not needed.
In order to successfully implement this design, it is necessary to provide a passage for the fluid to flow once it leaves the bearing, which is necessary to allow a pressure differential to form between the two sides of the nut threadform 28 in order to act as a restoring force. This is accomplished by making the root diameter 40 (minimum diameter) of the threadform 24 on the leadscrew less than the peak diameter 41 (minimum diameter) of the threadform 28 of the nut. Similarly, the maximum diameter 42 of the leadscrew thread 24 is less than the maximum diameter 43 of the nut. Typically, the difference in diameters should be on the order of 0.1-0.2 of the height of the thread. Freedom for the fluid to flow is also accomplished by drilling radial holes 21 in the nut to intersect the radial gap region 32. In the case of a single turn thread nut, radial holes are not required because the fluid that leaks into the radial clearance space then readily flows out the ends of the nut.
The second consideration is to allow the nut to function as its own coupling (i.e., self coupling) between itself and the leadscrew, and hence the movable carriage 15, such that only forces along the X axis are transmitted from the nut to the carriage, while forces and moments along and about the Y and Z axes (e.g., yaw and pitch) that could be generated or transmitted as a result of misalignment of the leadscrew axis with the axis of the movable carriage, are not generated or transmitted therebetween. If the teeth that form the threadforms of the leadscrew and nut have uniform cross sections, that is, the axial thickness at the root of each tooth substantially equals the thickness at the peak, then the nut will be able to move radially a small amount. Radial motion is accommodated by the aforementioned difference in diameters 40 and 41, and 42 and 43 of the leadscrew and nut respectively. The threadforms 24 and 28 have uniform cross sections. Thus the vertical threadform allows two of the required four degrees of freedom for coupling action. This means, however, that the leadscrew and the nut will not function unless the leadscrew 19 is anchored at both ends in bearings 18 and 20 and the nut 17 is rigidly attached to a linearly movable slide 15 that is supported by a linear bearing 16 that allows for primary motion only along the X axis. Error motions of the linear bearing will occur along and about axes orthogonal to the axis of linear motion, but these errors are allowed for by the self coupling nature of the leadscrew and nut. The self coupling nature of the leadscrew and nut allows error motions in the linear bearing to occur without resistance, thereby increasing their repeatability and the likelihood that they can be mapped and then compensated for digitally in the machine's controller.
The remaining two degrees of freedom required are those that prevent moments from being transmitted about axes that are orthogonal to the axis of the leadscrew (i.e., the Y and Z axes). If the fluid bearing interface between the threadforms were constructed only with orifices or other fluid flow control devices and independent recesses along the length of the thread helix, then the nut would transmit the undesirable moments. If, however, the recesses on each side of the threadform are connected together (but not to the recesses on opposite sides of the thread) to form a long helical groove that runs the length of the thread helix on the nut (but just shy of the ends of the helix), then the pressure along one side of the thread will be constant throughout. As the nut is rotated about the Y or Z axis through a small error motion of the linear bearing carriage that supports the nut, the gap, for example, between the left side of the thread on the upper side of the leadscrew opens while the gap on the left side of the thread on the lower side of the leadscrew closes. Usually, this would result in a correcting force couple (moment) being generated by a pressure differential resulting from one gap opening and one gap closing; however, if a pressure equalizing groove such as 22A which connects the recesses is cut or formed into the threadform to connect all the recesses fed by the orifices, then the pressure will equalize along one side of the thread and no force couple (moment) will be generated. An analogous situation exists for the right side of the thread. Thus the pressure equalizing grooves 22A and 22B act to prevent generation of moments about the Y and Z axes between the leadscrew and linear bearing carriage that supports the nut. The grooves 22A and 22B, as above noted, are radially-elongate depressions at each side of each tooth forming the nut threadform 28 and each groove is disposed along a helical path that extends axially along the nut threadform 28. These pressure equalizing grooves also act to allow the use of non rectangular threadforms such as Acme or triangular, while still allowing the nut to move radially. Use of a non rectangular threadform may be desirable in some special cases as they may be easier to grind or machine. The shape of the threadform will determine how much radial error motion can be tolerated before mechanical contact is made between threads. Although other different types of threadforms can be made to work, it has been found that the rectangular threadform, as shown in FIG. 2, maximizes ability of the design to provide the desired self-coupling action. Furthermore, it has been found that to maximize the coupling action (amount of error motion that can be accommodated) while matching stiffness of the nut to that of the leadscrew, the depth of the leadscrew thread should be on the order of one-quarter of the outside diameter of the leadscrew. In most instances, this allows a single turn of the nut thread to provide the required load carrying capability and stiffness. The nut shown in cross-section in FIG. 3 is a single-thread nut 17A which herein greatly diminishes problems associated with the manufacture of the two piece nut labeled 17 in FIG. 2 but, as previously noted, enhances self coupling between the nut 17A and the leadscrew. Use of a nut with a single turn thread nut allows the threadforms to be easily machined integral with the structural housing 54 (equivalent to part 30 in FIG. 2) despite the large depth of the thread. The single thread 53 with starting point labeled 52 and projecting out of the page of the drawing and ending at 51 in the plane of the drawing, is made 25% thinner, but with the same lead, as the threadform of the leadscrew. The nut can then be threaded over the leadscrew and epoxy poured or injected into the space between the threads of the nut and leadscrew. Through the use of putty and mold release wax, one can obtain proper radial and axial clearances and the helical grooves in the epoxy cast threads. This leaves great flexibility in manufacture of the rough nut threadform. For example, it could be turned on a lathe, investment cast, or machined from each side using a three axis milling machine.
FIG. 4 shows the self coupling nut after the epoxy has been cast and fluid supply holes drilled. The epoxy layer 55 adheres to the thread 53, and through the use of mold release wax and putty on the leadscrew threadform, allows the fluid distribution grooves 60A and 60B to be formed on each side of the thread 53. As noted earlier, the grooves run the length of the helix on each side of the thread, but the grooves are not connected and their ends are capped to prevent high pressure fluid from freely exiting the ends. In FIG. 4, the cross section cuts the thread at a point where the epoxy has not covered the ends of the threadform, and hence the grooves 60A and 60B still appear to be open at the ends. FIG. 4 also shows the nut with fluid flow control devices 57A and 57B in fluid supply holes 58A and 58B respectively. High pressure fluid would be supplied to the holes 58A and 58B, and the devices 57A and 57B would provide constant flow regardless of pressure to their respective grooves 60A and 60B through axial holes 59A and 59B. Constant flow devices make for a much higher stiffness bearing than do orifices which merely act as resistances which regulate flow as a function of pressure and orifice resistance (i.e. analagous to Ohms law, P=QR). Constant flow devices are commercially available, for example, from the Lee Company, Westbrook. Conn. USA.
For purposes of analyzing the achievable stiffness of the leadscrew and nut, it can be assumed that a fluidstatic bearing with properly sized orifices or other flow control devices and bearing area can conservatively achieve a load rating equal to the product of one half the projected area of the bearing with the maximum fluid pressure provided. If incorporated into a nut 17 with N turns of thread 28 and overlapping region between the thread of the leadscrew and nut of radii R o and R i , respectively, the maximum axial force, F axial max, the fluidstatic bearing nut can support when supplied with fluid at pressure P without making mechanical contact with the leadscrew is on the order of: ##EQU1## A conservative estimate for the apparent stiffness of the fluidstatic bearing is one half of the load divided by the equilibrium gap δ A between the threads: ##EQU2## The stiffness of the threadform itself also has to be considered. Since the depth of the thread may be on the order of its width t, shear as well as bending deformations must be considered. A conservative assumption is to assume that the width of an equivalent "beam" is equal to the length of the helix made by the thread, but that the helix form itself does not contribute to the stiffness of the "beam". The combined bending and shear stiffness K thread of the threads is: ##EQU3## where A is the area of the thread along its length, I is the second moment of the area, G and E are the shear and Young's modulus respectively, and L is the depth of the thread. Furthermore, let it be assumed that the equivalent of the distributed load applied by the pressurized air is a line force applied along the length of the helix at the midpoint of the threads height. The area, second moment of the beam cross section, and length of the beam are thus given by: ##EQU4## where t is the width of the thread, often equal to the pitch. Substituting these values into expression (3) gives the stiffness of the nut threads as a function of their physical dimensions and material properties (E and G are the Young's and shear modulii of the material the nut is made of, respectively). The leadscrew threads also deform by an equal amount, thus the combined thread stiffness is: ##EQU5## The stiffness of the leadscrew shaft is most often the "soft" link in a leadscrew/nut system. Assuming that the helix form of the thread does not contribute to the stiffness of the shaft, and the length of the shaft is l, the stiffness of the shaft is given by: ##EQU6## The total stiffness K total of the assembly is a function of all the component stiffnesses laid end to end which is given by the inverse sum of the inverses of the component stiffnesses: ##EQU7##
As a first example, consider the case where pressurized air is used the following dimensions and values are assumed:
t=0.188 inches
R o =1.0 inches
P=100 psi
R i =0.5 inches
l=20 inches
E=29×10 6 psi
G=11×10 6 psi
δ A =0.0002 inch
Then:
K shaft =1,138,826 lb/inch
K thread =5,019,438*N lb/inch
K fluid =294,524*N lb/inch
If N is only four threads, then the nut will be as stiff as the leadscrew with one million pounds per inch. The length of the nut required to accommodate the desired number of threads will be equal to twice the product of the lead and the number of threads. Thus for the above example, if the lead is one-half inch, the nut will be about four inches long.
As a second example, consider the case where pressurized oil is used the following dimensions and values are assumed:
t=0.188 inches
R o =1.0 inches
P=2000 psi
R i =0.5 inches
l=20 inches
E=29×10 6 psi
G=11×10 6 psi
δ A =0.001 inch
Then:
K shaft =1,138,826 lb/inch
K thread =5,019438*N lb/inch
K fluid =1,178,096*N lb/inch
Note that only one turn of the thread is required to achieve over one million pounds per inch stiffness and that since the gap is five times that of the gap for an air bearing, the angular self coupling abilities will be an order of magnitude greater than for the system that used pressurized air; however, one must remember that oil is a messy fluid to work with so in some cases air will still be the preferred fluid in some cases.
As shown by both of these examples, the nut can easily be twice as stiff as the leadscrew while having a reasonable size thread and lead. This also gives a stiffness almost twenty times that of a comparable rollerscrew or ballscrew equipped with a flexible coupling system that attempts to allow for potential misalignment forces and moments, along and about the other two axes that are orthogonal to the leadscrew axis. Also typically the depth of the thread of the invention will be on the order of the radius of the minor diameter leadscrew.
The leadscrew-nut system shown herein, with high, controlled fluid pressure between the threads of the leadscrew and the nut, results in high axial stiffness of the system with effectively zero stiffness in yaw, pitch, rotation and radial motion while inhibiting mechanical contact between the cooperative threads, thereby, in an operative system, to maintain the linear movement of the nut parallel to the leadscrew axis and thus providing means for self coupling action between the nut and the leadscrew.
Further modifications of the invention will occur to persons skilled in the art and all such modifications are deemed to be within the scope of the invention as defined by the appended claims.
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In a system that includes a linearly movable carriage or the like, a mechanism to convert rotary motion of a leadscrew to linear motion of a nut and, hence, linear movement of the carriage to which the nut is mechanically secured. The leadscrew has a special threadform and the nut has a special threadform that matches the threadform of the leadscrew with a pressurized fluid interface therebetween, there being both axial clearance and radial clearance sufficient to accommodate angular and lateral misalignment between the leadscrew and the carriage. Shallow independent grooves along each side of the nut's helical threadform act to equalize fluid pressure across each respective side of the threadform and orifices or other fluid flow control devices connect to the grooves or passages to permit introduction of high pressure air or other fluid thereto. Exhausts are provided from the region by radial clearance between the leadscrew threadform and the nut threadform. Both threadforms are ideally in the form of square threads, i.e., threads whose axial thickness of the root of each tooth substantially equals the axial thickness of the peak thereof, i.e., rectangular threads. Also, for best results, the nut should have a single threadform of depth equal to about one-quarter the major diameter of the leadscrew, where the final shape of the nut thread is finish cast with epoxy to the shape of the screw using putty and mold release wax to attain necessary oil flow grooves and radial and axial clearance.
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CROSS REFERENCE TO RELATED PATENT APPLICATION
[0001] The present patent application claims the right of priority under 35 U.S.C. § 119 (a)-(d) of German Patent Application No. 10 2006 040 566.8, filed Aug. 30, 2006.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to sturdy, transparent, elastomeric polyurethane moldings, a process for production thereof, and the use thereof.
[0003] Sturdy, transparent polyurethane (PUR) elastomers have been known for a long time, and suitable for use in a wide variety of end-use applications. Polyurethane gels as described in DE-A 100 24 097 are particularly worth mentioning here.
[0004] In general, polyurethane gels are transparent materials with a high specific weight. They are distinguished by certain mechanical properties, such as, for example, good shock-absorption. This viscoelastic behavior is particularly well pronounced in relatively thin layers. As an example here, the use of PUR gels in heel cushion pads may be mentioned. However, if the layer thickness is too great, it is observed that the energy-absorption of the material becomes very high. However, a lower damping, especially in this end-use application, is more favorable for physiological considerations and reasons. [See Dissertation Walter M., Zusammenhänge zwischen der subjektiven Beurteilung von Laufschuhen, den Materialdaten, sowie kinetischen und kinematischen Parametern des Gangzyklus , Universität Würzburg, 2001].
[0005] Another disadvantage of these dimensionally stable gels lies in their production. In this connection, a long-chain polyol is reacted with a polyisocyanate at a low index. By virtue of this so-called undercuring, the required processing times are frequently too long. Furthermore, the molding has a tacky surface. A tack-free surface can be generated in an additional working step by encasing the gels with coatings of different kinds. A further disadvantage is the deficient adhesion between the gel and the covering layer which, for example, may consist of leather or other textiles (such as, for example, in the case where gels are being used for midsoles).
[0006] Despite the disadvantages, PUR gels are frequently used in moldings due to their appealing transparent optical properties.
[0007] The object of the present invention was to provide polyurethane moldings that do not exhibit the disadvantages of the PUR gels which have been described (e.g. long demolding-times, tacky surfaces and high damping), but which at the same time also possess an optically interesting and appealing, attractive external appearance, and which exhibit a selectively adjustable elasticity.
[0008] Surprising, the present object was achieved by means of the sturdy, transparent, elastomeric polyurethane moldings according to the invention.
SUMMARY OF THE INVENTION
[0009] The present invention provides sturdy, unfilled, transparent moldings which comprise a polyurethane elastomer, in which the molded part exhibits bubble-free, transparent, optical properties, and has a tack-free surface. These polyurethane elastomers comprise the reaction product of:
[0000] (A) a polyol formulation comprising of:
[0010] a) a polyol component comprising:
a1) at least one polyether polyol having an OH number of from 20 to 112, a functionality of 2, containing ≧45% by weight of primary OH groups, and which is the alkoxylation product of a suitable initiator with propylene oxide and/or ethylene oxide; and a2) at least one polyether polyol having an OH number of from 20 to 112, a functionality from greater than 2 to 6, containing containing ≧45% by weight of primary OH groups, and which is the alkoxylation product of a suitable initiator with propylene oxide and/or ethylene oxide;
[0014] b) one or more chain-extenders and/or crosslinking agents which has an OH number of from 600 to 2000;
[0015] c) one or more catalysts;
[0016] and, optionally,
[0017] d) one or more additives;
[0000] with
[0000] (B) an isocyanate component;
[0018] wherein the equivalent ratio of the NCO groups of (B) the isocyanate component to the sum of the hydrogen atoms of components a), b) and c) which are reactive in relation to isocyanate groups, ranges from 0.8:1 to 1.2:1, preferably from 0.95:1 to 1.15:1, and more preferably from 0.98:1 to 1.05:1.
[0019] The present invention also provides a process for producing sturdy, unfilled, transparent moldings which comprise polyurethane elastomers. These molded parts of polyurethane elastomer exhibit bubble-free, transparent optical properties, and have a tack-free surface.
[0000] This process comprises reacting or mixing:
[0000] (A) a polyol formulation comprising:
[0020] a) a polyol component comprising:
a1) at least one polyether polyol having an OH number of from 20 to 112, a functionality of 2, containing ≧45% by weight of primary OH groups, and which is the alkoxylation product of a suitable initiator with propylene oxide and/or ethylene oxide; and a2) at least one polyether polyol having an OH number of from 20 to 112, a functionality from greater than 2 to 6, containing containing ≧45% by weight of primary OH groups, and which is the alkoxylation product of a suitable initiator with propylene oxide and/or ethylene oxide;
[0024] b) one or more chain-extenders and/or crosslinking agents which has an OH number of from 600 to 2000;
[0025] c) one or more catalysts;
[0026] and, optionally,
[0027] d) one or more additives;
[0000] with
[0000] (B) an isocyanate component;
[0000] placing the mixture into a mold, and curing the mixture for no more than 5 minutes.
[0028] As discussed above, the equivalent ratio of the NCO groups of (B) the isocyanate component to the sum of the hydrogen atoms of components a), b) and c) that are reactive in relation to isocyanate groups ranges from 0.8:1 to 1.2:1, preferably 0.95:1 to 1.15:1, and more preferably 0.98:1 to 1.05:1.
DETAILED DESCRIPTION OF THE INVENTION
[0029] The diisocyanates suitable for use in the present invention as component (B) include those known diisocyanates from polyurethane (PUR) chemistry, and preferably aromatic diisocyanates. In a preferred embodiment, prepolymers of diisocyanates are used. In particular, the preferred prepolymers comprise the reaction product of (1) 4,4′-diphenylmethane diisocyanate and/or modified 4,4′-diphenylmethane diisocyanate, with (2) a mixture comprising (a) one or more polyether polyols having an OH number of from 10 to 112, and (b) one or more polyethylene glycols and/or one or more polypropylene glycol having a molecular weight of from 135 to 700 g/mol. Suitable diisocyanates include, for example, those which have been modified such that they contain carbodiimide groups and/or allophanate groups.
[0030] Suitable compounds to be used as components a1), a2), b), c) and d) in the polyol formulation (A) are well-known. These are compounds which are all typically used in polyurethane chemistry.
[0031] The moldings of the invention preferably have a density ranging from 1050 kg/m 3 to 1200 kg/m 3 .
[0032] These sturdy, elastomeric polyurethane moldings are suitable for use as, for example, various industrial articles and common consumer articles of daily use, and, in particular, as shoe soles and as shoe inserts.
[0033] The invention is explained in more detail in the following Examples.
[0034] The following examples further illustrate details for the process of this invention. The invention, which is set forth in the foregoing disclosure, is not to be limited either in spirit or scope by these examples. Those skilled in the art will readily understand that known variations of the conditions of the following procedures can be used. Unless otherwise noted, all temperatures are degrees Celsius and all percentages are percentages by weight.
EXAMPLES
[0035] For the purpose of producing the moldings, the two components A (i.e. the polyol formulation) and B (i.e. the isocyanate component) were blended with one another by means of a screw (Klöckner Desma, Achim). The reaction mixture comprising the polyol formulation and the isocyanate was put into an open mold and cured.
[0036] Component A, having a material temperature of 30° C., was mixed with the NCO prepolymer component B, likewise with a material temperature of 30° C. The mixture was poured into an aluminium hinged mold (size 200 mm×70 mm×10 mm) which was maintained at a constant temperature of 50° C., and the hinged mold was closed. The molding was removed from the mold after a few minutes.
[0037] The Shore-A hardness according to DIN 53505, after storage for 24 h, was determined for the moldings produced in this way. Furthermore, the resilience according to DIN 53512 was ascertained. Moreover, indentation tests in accordance with DIN 53579, subsection IV, were carried out in respect of moldings.
[0038] The results of measurement are summarised in Table 1 below.
[0000] Starting Materials:
[0000] Polyether Polyols:
[0000]
1) A mixture of tripropylene glycol and a polyether polyol based on propylene oxide, in which the mixture has a hydroxyl number of 163.
2) A polyether polyol having a hydroxyl number of 28, which contains 70% propylene-oxide units and 30% ethylene-oxide units with propylene glycol as the initiator, and contains 90% primary OH groups.
3) A polyether polyol having a hydroxyl number of 56, which contains 86% propylene-oxide units and 14% ethylene-oxide units with glycerine as the initiator, and contains about 45% primary OH groups.
4) A polyether polyol having a hydroxyl number of 28, which contains 82% propylene-oxide units and 18% ethylene-oxide units with sorbitol as the initiator, and contains 85% primary OH groups.
5) A polyether polyol having a hydroxyl number of 56, which contains 40% propylene-oxide units and 60% ethylene-oxide units with trimethylolpropane as the initiator, and contains >90% primary OH groups.
Isocyanate Component:
1) A prepolymer having an NCO-content of 19.8%, prepared by reacting 66 parts by weight of 4,4′-diisocyanatodiphenylmethane (4,4′-MDI), 5 parts by weight modified 4,4′-MDI having an NCO-content of 30% (that is prepared by partial carbodiimidisation), and 29 parts by weight of polyether polyol 1).
2) A polymer-containing prepolymer having an NCO-content of 31.5% (commercially available as Desmodur 44V10L from Bayer MaterialScience AG).
Example 1
According to the Invention
[0000] The polyol formulation (A) comprised:
[0000] 3712.50 parts by weight of the difunctional polyether polyol 2),
[0000] 1125.00 parts by weight of polyether polyol 3),
[0000] 75.00 parts by weight Dabco in ethylene glycol,
[0000] 25.00 parts by weight diethylene glycol,
[0000] 50.00 parts by weight triethanolamine,
[0000] 12.50 parts by weight dimethyl-bis[(1-oxoneodecyl)oxy]stannane.
[0000] 100 parts by weight of this polyol component were mixed with 24 parts by weight of prepolymer 1.
Example 2
According to the Invention
[0000] The polyol formulation (A) comprised:
[0000] 3712.50 parts by weight of the difunctional polyether polyol 2),
[0000] 1125.00 parts by weight of polyether polyol 4),
[0000] 75.00 parts by weight Dabco in ethylene glycol,
[0000] 25.00 parts by weight diethylene glycol,
[0000] 50.00 parts by weight triethanolamine,
[0000] 12.50 parts by weight dimethyl-bis[(1-oxoneodecyl)oxy]stannane.
[0000] 100 parts by weight of this polyol component were mixed with 25 parts by weight of prepolymer 1.
Example 3
Comparison
[0000] The polyol formulation (A) comprised:
[0000] 1000 parts by weight of the trifunctional polyether polyol 5),
[0000] 10 parts by weight Dabco in dipropylene glycol.
[0000] 100 parts by weight of this polyol component were mixed with 5 parts by weight of prepolymer 2.
Example 4
Comparison
[0046] A polyol formulation (A) (polyether polyol 2), polyetherpolyol 3), Dabco in ethylene glycol and dimethyl-bis-[(1-oxo-neodecyl)oxy]stannane) was mixed with prepolymer 1.
[0047] Without a chain extender/crosslinking agent almost no reaction took place; the mixture stayed liquid and did not become solid. The use of another, stronger catalyst (tin catalyst UL-32) was not successful, the mixture stayed liquid.
Example 5
Comparison
[0048] A polyol mixture (10 parts by weight of a polyetherpolyol {OH number 36, functionality F=3, TMP as a starter, 20% ethylene oxide, 80% propylene oxide}, 40 parts by weight of a polyetherpolyol {OH number 56, F=2, PG as a starter, 100% propylene oxide}, 50 parts by weight of a polyetherpolyol {OH number 56, F=3, TMP as a starter, 55% ethylene oxide, 45% propylene oxide}) and Coscat 83 (catalyst) were mixed with Desmodur® N3400 from Bayer MaterialScience AG.
[0049] There was almost no reaction so that the mixture stayed liquid.
TABLE 1 Example 1 Example 2 Example 3 Hardness 48/67 43/67 17/40 [Shore A]/[Asker C] Resilience 53 48 25 [%] Rel. energy-absorption 0.17 0.27 0.33 ΔW* Minimum demolding- 3.5 3 5.5 time [min]** Optics/Surface transparent transparent transparent dry dry tacky Deformation [mm]*** 0.65 0.82 3.11 *The energy-absorption ΔW is also called damping and was obtained by measuring the work done during loading of a sample in Newton and work during removal of the load from the sample, using the equation: ΔW = [W(loading) − W(removing load)]/W(loading) **Minimum demolding-time is the time required to be able to remove the molded part from the mold, without deformation, and for the surface to be no longer tacky. ***Deformation in mm is determined by applying a constant force of 150 N to the sample.
[0050] As is evident from Table 1, Examples 1 and 2 according to the invention display
1.) a better demolding behavior (i.e. a shorter demolding-time), 2.) a transparent optical property with a dry, tack-free, bubble-free surface, 3.) a clearly lower deformation and, associated therewith, lower absorption of energy,
and
4.) with almost constant degrees of hardness, selectively adjustable values of resilience.
[0055] Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
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The invention relates to sturdy, transparent, elastomeric polyurethane moldings, to a process for production thereof, and also the use of these moldings.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to calcitonin (CT). More particularly, the present invention relates to the expression of calcitonin in yeasts.
[0003] 2. Description of the Related Arts
[0004] Calcitonin was identified as a hormone factor for reducing the concentration of calcium ion in serum in 1962. It was also noted that calcitonin is secreted by C-cells from the thyroid gland. Busolati G et al. (1967) proposed that calcitonin is composed of 32 amino acids, the first and the seventh cysteines have a disulfide bond, and proline at the C-terminal end is amidated. Sexton, P. M. et al. (1999) reported that the amidation of proline at the C-terminal end is critical for the bioactivity of calcitonin. In vitro study by Sexton, P. M. et al. (1983) and in vivo study by Chamber, T. J. et al. (1983) have demonstrated that the adenylyl cyclase and cAMP dependent protein kinase can be activated by the binding of calcitonin and calcitonin receptor on cell membrane to decrease osteoclast activity thereby alleviating osteoporosis. It is known that calcitonin anticipates calcium ion metabolism and inhibits osteoporosis resulting from osteoclast activity; therefore, calcitonin is considered an effective agent for the treatment of osteoporosis.
[0005] Gennari, C. et al. (1999) and Avioli, L. V. (1997) reported that calcitonin provides both a treatment and a preventive effect. Calcitonin can be used clinically to treat bone disorders, such as Paget's disease, osteoporosis, hypercalcemia malignancy. At present, the clinically used calcitonin is derived from human, salmon, porcine, and eel. Sexton, P. M. et al. (1999) reported that the bioactivity of calcitonin derived from salmon is especially high compared to other sources. The present clinically used calcitonin is manufactured through chemical synthesis, which is costly and limited by the length of amino acids. With the development of molecular technology in the last decade, a trend of protein drug production using living organisms (Ivanov, I. 1987; Ishikawa, H. 1996; 1999) has been arisen.
[0006] The present technology using recombinant proteins to produce calcitonin can be classified as Escherichia coli production, animal cell production, and yeast production. The advantages and disadvantages of the three productions are discussed in the following.
[0007] U.S. Pat. No. 6,210,925B2 to Unigene Laboratories, Inc. discloses a method for calcitonin production by E. coli having the advantage of high production; however, the formation of inclusion bodies in E. coli decreases the solubility of calcitonin.
[0008] Takahashi K. I. et al. (Peptides, 1997; 18(3):439-444) disclose a method for calcitonin production by nonendocrine animal cell lines, such as COS-7 and CHO. The last amino acid of the precursor of recombinant calcitonin is glycine which can be amidated easily and the product is identical to naturally occurring calcitonin without any chemical modification. The disadvantages of this method include low production rate and high cost.
[0009] Micronova R. et al. (FEMS Microbiology Letter, 1991; 67(1):23-28) disclose a method for human calcitonin production by Saccharomyces cerevisiae . The product can be secreted to the medium and any purification process is unnecessary. The production rate in yeast is between the rates of animal cells and E. coli , however, an additional C terminal amidation is necessary.
[0010] The above mentioned methods have several disadvantage, hence there is still a need for calcitonin production with high production rate and simple purification process.
SUMMARY OF THE INVENTION
[0011] It is therefore a primary object of the present invention to provide an optimized calcitonin DNA sequence back-translated from a modified calcitonin amino acid sequence in accordance with the codon usage of Saccharomyces cerevisiae to obtain optimized calcitonin expression in yeasts.
[0012] Accordingly, one aspect of the present invention features a separate nucleic acid encoding recombinant salmon calcitonin, comprising a nucleotide sequence of SEQ ID No. 2.
[0013] The second aspect of the present invention features an expression vector of recombinant calcitonin, comprising a nucleotide sequence of recombinant salmon calcitonin as shown in SEQ ID No. 2.
[0014] In another aspect of the present invention, a method for the production of recombinant calcitonin is provided. The method includes the steps of introducing the above expression vector of recombinant calcitonin into a cell, culturing the cell under a condition suitable for the expression of the recombinant calcitonin, and collecting and purifying the recombinant calcitonin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The present invention will be more fully understood and further advantages will become apparent when reference is made to the following description of the invention and the accompanying drawings in which:
[0016] [0016]FIG. 1 is a diagram illustrating a one-copied expression vector (pYEUαSOAK) and the inserted fragment (sCT) in the example of the invention.
[0017] [0017]FIG. 2 is a photograph showing the sCT:::SOAMY fusion protein in the example of the invention. The left two lines are the expression in EJ758, and the right two lines are the expression in W303; 1 represents negative control, 2 and 3 represent arbitrarily selected two pYEUαSOAK-sCT.
[0018] [0018]FIG. 3 is a diagram illustrating a multiple-copied expression vector (pYEUUαSOAK) and the inserted fragment (2u circle DNA) in the example of the invention.
[0019] [0019]FIGS. 4A and 4B are photographs showing the comparison of CT-amylase fusion protein. FIG. 4A represents the electrophoresis result of the expression in DY150-1 and DY150-2; FIG. 4B represents the electrophoresis result of the expression in CK16-1 and CK16-2, and the block underneath represents the activity of the fusion protein. M represents molecular weight marker, the left arrow indicates 66KD and 55KD, and the right arrow indicates 57KD which is the molecular weight of the fusion protein in the invention.
[0020] [0020]FIG. 5 is a photograph showing the standard quantitative results of the fusion protein and amylase in CK16 after 86 hours. The left four lines are the comparative basis of a standard amylase in 0.5, 1.0, 2.0, and 5.0 μg; the right four lines are the fusion protein of the invention in 0.5, 1.0, 2.0, and 5.0 μg. The calculated production of the invention is about 0.5 μg/5 μg=0.1 g/L.
[0021] [0021]FIG. 6 is a diagram showing the map of pYEUαsCT in the invention.
[0022] [0022]FIG. 7 is a photograph showing the comparison of sCT5 secretion in 6 yeast strains. M represents molecular weight marker, + represents positive control, 1 represents CK16, 2 represents DY150, 3 represents AH109, 4 represents TL154, 5 represents Y187, and 6 represents BJ168.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Without intending to limit the invention in any way, the present invention will be further illustrated by the following description.
[0024] Calcitonin is a hormone protein with a short peptide composed of 32 amino acids. The molecular weight of calcitonin is too small to be analyzed by protein electrophoresis since it cannot be stained easily and may be mixed with small-molecular short-peptides in the bacterial broth. In addition, the bioactivity of calcitonin has to be demonstrated via complicated osteoblast cell culture or animal experiment. The invention provides a simple method for the preparation of calcitonin with a yeast expression vector ligated with an artificial calcitonin designed from naturally occurring salmon calcitonin.
[0025] The naturally occurring salmon calcitonin nucleotide sequence designated as S74353 in GENEBANK are shown as below:
(SEQ ID No. 1) TGC TCC AAC CTC AGC ACC TGT GTG CTG GGC Cys Ser Asn Leu Ser Thr Cys Val Leu Gly 10 AAA CTG TCC CAA GAG CTG CAC AAA TTG CAG Lys Leu Ser Gln Glu Leu His Lys Leu Gln 20 ACG TAC CCC CGC ACC AAC ACG GGA AGT GGC Thr Tyr Pro Arg Thr Asn Thr Gly Ser Gly 30 ACG CCT Thr Pro 32
[0026] In view of the amino acid sequence of calcitonin, it is noted that the sequence of salmon calcitonin has 6 high usage codons and 26 low usage codons in accordance with the codon usage table of Saccharomyces cerevisiae as shown in table 1.
TABLE 1 The codon usage of Saccharomyces cerevisiae Ala GCT 0.37 GCA 0.30 Pro CCA 0.41 CCT 0.31 GCC 0.22 GCG 0.11 CCC 0.16 CCG 0.12 Arg AGA 0.47 AGG 0.21 Leu TTG 0.28 TTA 0.28 CGT 0.14 CGA 0.07 CTA 0.14 CTT 0.13 CGC 0.06 CGG 0.04 CTG 0.11 CTC 0.06 Asn AAT 0.60 AAC 0.40 Lys AAA 0.58 AAG 0.42 Asp GAT 0.65 GAC 0.35 Met ATG 1.0 Cys TGT 0.62 TGC 0.38 Phe TTT 0.59 TTC 0.41 Gln CAA 0.68 CAG 0.32 Trp TGG 1.0 Glu GAA 0.70 GAG 0.30 Tyr TAT 0.57 TAC 0.43 Gly GGT 0.45 Ser TCT 0.26 TCA 0.21 GGA 0.23 GGC 0.20 TCC 0.16 AGT 0.16 GGG 0.12 TCG 0.10 AGC 0.11 His CAT 0.64 CAC 0.36 Thr ACT 0.34 ACA 0.31 ACC 0.21 ACG 0.14 Ile ATT 0.46 Val GTT 0.39 GTA 0.22 ATA 0.28 ATC 0.26 GTC 0.20 GTG 0.20
[0027] The salmon calcitonin nucleotide sequence was designed by modifying the codons with low usage rate to have a high usage rate, and the expression of calcitonin in yeasts was then optimized.
[0028] The resulting recombinant salmon calcitonin nucleotide sequence of the invention is shown as below:
(SEQ ID No. 2) TGT TCT AAT TTG TCT ACT TGT GTT CTA GGT Cys Ser Asn Leu Ser Thr Cys Val Leu Gly 10 AAA TTA TCA CAA GAA TTA CAT AAA TTG CAG Lys Leu Ser Gln Glu Leu His Lys Leu Gln 20 ACT TAT CCA AGA ACC AAT ACA GGT TCA GGA Thr Tyr Pro Arg Thr Asn Thr Gly Ser Gly 30 ACA CCT Thr Pro 32
[0029] In addition, a recombinant expression vector for the extracellular secretion of calcitonin fusion protein was constructed. It is noted that calcitonin has an amino acid sequence “Asn-x-Thr/Ser” which may be modified by glycosylation. The glycosylation of this sequence may change the molecular weight and antigenicity of calcitonin and the secreted calcitonin will then be undetectable and cannot be used. To avoid the possible glycosylation of this amino acid sequence during the yeast secretion process, mutant strains with low glycosylation is applied. Moreover, the detection of calcitonin produced from yeasts includes calcitonin antibody detection or the detection of the fusion protein activity. When a suitable expression vector and suitable transformed strains are selected, the expression vector can be constructed again to express calcitonin alone.
[0030] Therefore, the invention features an expression vector of a recombinant salmon calcitonin comprising a recombinant salmon calcitonin gene of SEQ ID No. 2. In a preferred embodiment, the expression vector is pYEUαSOAK-sCT.
[0031] Another aspect of the invention features a method of producing a recombinant calcitonin, comprising the steps of: introducing the expression vector of the recombinant salmon calcitonin into a cell, culturing the cell in a condition suitable for the expression of the recombinant calcitonin, and collecting and purifying the recombinant calcitonin.
[0032] Practical examples are described herein.
EXAMPLE
Example 1
Synthesis of a Full-Length Calcitonin by Gene combination
[0033] First, the full-length calcitonin was designed in accordance with the codon usage table of Saccharomyces cerevisiae to be shown as the sequence of SEQ ID No.2. Two primers of about 60 bp were also designed for the sequence. The two primers sharing 20 bp complementary nucleotides are shown as below.
TGT GGT AAT TTG TCT ACT TGT ATG TTA GGT ACA TAT ACC CAA (SEQ ID No. 3) GAT TTT AAT AAA TTC CAT AGG TGC GCC AAC TCC AAT AGC AGT TTG TGG AAA TGT ATG GAA (SEQ ID No. 4) TTT ATT AAA ATC TTG GGT
[0034] The full-length calcitonin was synthesized by PCR. The 50 μl of reaction solution includes 1 μl each of the two primers (0.1 μg/μl), 4 μl of 2.5 mM dNTPs, 5 μl of 10× Taq Plus buffer, 1 μl of 3U/μl Taq-Pfu and 38 μl of ddH 2 O. The reaction was performed in a Gene Amp PCR system 2400 (Perkin Elmer) under a condition of: 1 cycle of 98° C. for 5 min, 30 cycles of 98° C. for 2 min, 60° C. for 2 min, 72° C. for 2 min, and a final cycle of 72° C. for 5 min. The PCR product is the full-length calcitonin gene.
[0035] The PCR product was used as the template for the second PCR to synthesize calcitonin with restriction sites. Two primers were designed to include XhoI and SnaBI sites, as shown below:
TGT TCT AAT TTG TCT ACT TGT GTT CTA GGT AAA TTA TCA CAA (SEQ ID No. 5) GAA TTA CAT TTG CAG AGG TGT TCC TGA ACC TGT ATT GGT TCT TGG ATA AGT CTG CAA (SEQ ID No. 6) ATG TAA TTC TTG TGA
[0036] The 50 μl of reaction solution includes 2.4 μl of the first PCR product, 1 μl each of the two primers (0.5 μg/μl), 2 μl of 2.5 mM dNTPs, 5 μl of 10× Taq Plus buffer, 1 μl of 3U/μl Taq-Pfu enzyme and 27.6 μl of ddH 2 O. The reaction was performed in a Gene Amp PCR system 2400 (Perkin Elmer) under a condition of: 1 cycle of 98° C. for 5 min, 25 cycles of 98° C. for 1 min, 60° C. for 1 min, 72° C. for 1 min, and a final cycle of 72° C. for 5 min. The PCR product is the calcitonin gene with XhoI and SnaBI restriction sites.
Example 2
The construction of a expression vector for sCT:::SOAMY secretion
[0037] The vector named as pYEUαSOAK (Yeastern Biotech Co., Ltd., Taiwan) was constructed to include centromere (CEN4) and autonomous replicative sequence (ARS). The vector has a length of 9.4kb and includes an amylase gene SOAMY with a secretion signal αFL. The map of the vector is shown in FIG. 1. The vector is a circular molecule and can be simultaneously replicated with the yeast chromosome to maintain 1-3 vector molecules for each yeast cell. With this system, the physiology and metabolism of the host cell are not influenced by high intracellular molecules, and the exogenous protein produced in the host cell will not damage the entire host cell. The preferred host cell or vector can be then selected more objectively.
[0038] The detailed construction is shown in FIG. 1. The salmon calcitonin (sCT) was inserted into pYEUαSAOK to form a fusion gene of α-FL:::sCT:::SOAMY. The procedure is recited below. The calcitonin gene fragment with XhoI and SnaBI restriction sites obtained from EXAMPLE 1 and pYEUαSAOK were digested separately. The XhoI digestion was performed first. 50 μl of pYEUαSOAK(1 μg) was added with 2 μl of XhoI(20U), 0.6 μl of BSA(10 mg/ml), 6 μl of 10× buffer, and 1.4 μl of ddH 2 O to form a total volume of 60 μl. 35 μl of the calcitonin gene fragment obtained from EXAMPLE 1 was added with 2 μl of XhoI (20U), 0.45 μl of BSA(10 mg/ml), 6 μl of 10× buffer, and 3.05 μl of ddH 2 O to form a total volume of 45 μl. The two reactions were incubated at 37° C. for 16 hours, and SnaBI digestion was then performed. 60 μl of the digested pYEUαSOAK was added with 4 μl of SnaBI (20U), 0.1 μl of BSA (10 mg/ml), 1 μl of 10× buffer, and 4.9 μl of ddH 2 O to form a total volume of 70 μl. 45 μl of the digested calcitonin gene fragment was added with 4 μl of SnaBI (20U), 0.25 μl of BSA (10 mg/ml), 2.5 μl of 10× buffer, and 19.25 μl of ddH 2 O to form a total volume of 70 μl. The two reactions were incubated at 37° C. for 4 hours. The digested products were purified by a PCR clean-up kit.
[0039] Ten μl of the ligation reactants included 1 μl of sCT, 1 μl of pYEUαSOAK, 1 μl 10× ligase buffer, 1 μl of ligase, and 6 μl of ddH 2 O, and the ligation reaction was performed at 16° C. for 12-16 hours. The next step was transformation. 5 μl of ligated product was added into 100 μl of TOP10 competent cell (stratagene). After a 30 min ice bath, 37° C. incubation for 3 min, and a 10 min ice bath, the bacteria were applied onto an LB/Amp medium and incubated at 37° C. for 16 hours. 10-20 colonies on the LB/Amp medium were separately applied to 200 μl of LB/Amp broth and incubated at 37° C. for 1-2 hours. The colony PCR was performed with a total reaction of 25 μl including 1 μl of the culture broth, 0.5 μl each of primer 1 and 2 (20 μM), 1 μl of dNTPs(2.5 mM), 2.5 μl of 10× Taq buffer, 1 μl of Taq(3U/μl), and 19 μl of ddH 2 O. The colony PCR was performed in a Gene Amp PCR system 2400 (Perkin Elmer) under a condition of: 1 cycle of 98° C. for 5 min, 25 cycles of 98° C. for 1 min, 55° C. for 1 min, 72° C. for 1 min, and a final cycle of 72° C. for 5 min. The transformant can be confirmed quickly. After sequencing, pYEUαSOAK-sCT was obtained. The vector has GAL1/10 promoter for galactose induction; therefore, the detection of amylolysis acted by SOAMY represents sCT was successfully translated as a part of the fusion protein and secreted into the medium. In addition, the centromere and ARS of the vector provide simultaneously replication with the yeast chromosome and maintain the stability of the vector in the yeast. As shown in FIG. 2, it is confirmed that sCT:::SOAMY was secreted from the transformants cultured in a solid medium with starch. A negative control (1) and two arbitrary pYEUαSOAK-sCT (2 and 3) were transformed into yeasts EJ758 and W303, respectively, and cultured in YNBD medium (leu+Ura+His+Ala+Met) at 28° C. for 2 days. The results show that the α-amylase reaction did not appear in the negative control, but did appear in both transformants of pYEUαSOAK-sCT. In addition, the bacterial growth in the transformants was normal as in the control group. These results confirmed that the sCT:::SOAMY fusion protein from a one-copied expression vector can be secreted in transformants. Next, a multi-copied vector was constructed for better secretion, and suitable strains for large scale secretion were then screened.
[0040] As shown in FIG. 3, the expression vector with multiple copies was constructed by replacing CEN-ARS1 with 2μ-ori. The replacement was performed by the restriction sites of SpeI and SspBI. The digestion procedure is similar to the above mentioned steps. The obtained expression vector was designated as pYEUαSOAK2μ-sCT.
Example 3
Screening of Saccharomyces cerevisiae Strains for sCT:::SOAMY Fusion Protein and Quantification of the Fusion Protein
[0041] The pYEUαSOAK2μ-sCT obtained by EXAMPLE 2 was transformed into 8 strains of Saccharomyces cerevisiae (DY150-1 (Yeastern Biotech Co., Ltd., Taiwan), DY150-2 (Yeastern Biotech Co., Ltd., Taiwan), CK16-1 (Yeastern Biotech Co., Ltd., Taiwan), CK16-2 (Yeastern Biotech Co., Ltd., Taiwan), TL154 (ATCC 96030), AH109 (Clontech com), Y187 (ATCC 96399), and BJ168 (ATCC 4000168)), the strains were cultured in YNBD medium (leu+Ura+His+Ala+Met), and the yeasts were collected at 23, 38, 62, 86 hours. The results were confirmed with SDS-PAGE electrophoresis and coommassie blue staining. It was found that the secretion of the fusion protein in different strains is significantly different as shown in FIGS. 4A and 4B. FIG. 4A shows two mutant strains of a commercialized DY150 strain: DY150-1 and DY150-2, and FIG. 4B shows two mutant strains of CK16 strain which is commonly used for exogenous protein secretion: CK16-1 and CK16-2; the arrow indicates a molecular weight of 57kD which is the size of the fusion protein in the invention. The results shows that the product secreted by CK16 strains has cumulative ability and the activity of the fusion protein is also cumulative, as shown in the bottom of FIG. 4B.
[0042] To determine the quantity of the calcitonin fusion protein, the expression vector of calcitonin fusion protein was transformed to CK16, and the transformed CK16 was cultured for 86 hours and collected. The product was confirmed by SDS-electrophoresis and Coommassie blue staining. The comparative results of the product and standard Aspergillus α-amylase (Sigma) are shown as FIG. 5. Lines 1, 2, 3, and 4 represent the standard Aspergillus α-amylase diluted to 0.5 μg{grave over ()}1.0 μg{grave over ()}2.0 μg{grave over ()}5.0 μg; lines 5, 6, 7, and 8 represent 86-hour cultured transformed CK16 in 5.0 μl, 2.0 μl, 1.0 μl, and 0.5 μl. The productivity of sCT:::SOAMY fusion protein after 86 hours culturing can be estimated as more than 0.5 μg/5 μl. In the other words, 1 L of transformed yeast may produce more than 100 mg of sCT:::SOAMY fusion protein.
[0043] It was found that the influence of different strains on the production of sCT:::SOAMY fusion protein is significant. The commercialized strains such as DY50 have low production rate because the product that experienced over-glycosylation has different molecular weight or is hydrolyzed by protease. This indicates that the genetic influence of strains is important for sCT:::SOAMY fusion protein expression.
Example 4
Construction of YEUαsCT Including sCT Alone and Production of sCT with a Molecular Weight of 4 kd
[0044] The results of EXAMPLE 3 proved that sCT:::SOAMY fusion protein can be produced. To produce sCT alone, a sCT expression vector without SOAMY was constructed and designated as pYEUαsCT. The map of pYEUαsCT is shown in FIG. 6. The molecular weight of sCT produced from this expression vector is about 4kd.
[0045] The sCT of 4kd in pYEUαsCT transformants was determined by silver staining, as shown in FIG. 7. 6 pYEUαsCT transformants, including 1: CK16, 2: DY150, 3: AH109, 4: TL154, 5: Y187, and 6: BJ168, and one positive control (chemically synthesized sCT, “+”) are shown in FIG. 7. The results indicate that 1 and 5 produced the predicted product at 4kd consistent with the molecular weight of the positive control (+). Compared with the positive control, the production rate is about 5 mg/L. Note that the yeasts were not cultured in a fermentor
[0046] These examples show that the expression vector including the recombinant salmon calcitonin of the invention can be used in a specific saccharomyces cerevisiae such as CK16 to produce salmon calcitonin with a high production rate. In addition, the protein produced by Saccharomyces cerevisiae is safe. The present chemically synthetic protein has the disadvantages of high cost and is limited by the length of amino acids. The yeast production system of the invention reduces the cost and overcomes the length limitation of chemical synthesis.
[0047] While the invention has been particularly shown and described with the reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.
0
SEQUENCE LISTING
<160> NUMBER OF SEQ ID NOS: 7
<210> SEQ ID NO 1
<211> LENGTH: 96
<212> TYPE: DNA
<213> ORGANISM: Oncorhynchus gorbuscha
<300> PUBLICATION INFORMATION:
<301> AUTHORS: Martial, K., Maubras, L., Taboulet, J., Jullienne,
A., Milhaud,
G., Moukhtar, M.S. and Cressent, M
<302> TITLE: Production of salmon calcitonin I in Oncorhynchus
gorbuscha by
<303> JOURNAL: Gene
<304> VOLUME: 149
<305> ISSUE: 2
<306> PAGES: 277-281
<307> DATE: 1994-11-18
<313> RELEVANT RESIDUES: (16)..(111)
<400> SEQUENCE: 1
tgctccaacc tcagcacctg tgtgctgggc aaactgtccc aagagctgca caaattgcag 60
acgtaccccc gcaccaacac gggaagtggc acgcct 96
<210> SEQ ID NO 2
<211> LENGTH: 96
<212> TYPE: DNA
<213> ORGANISM: artificial
<220> FEATURE:
<223> OTHER INFORMATION: modified to be suitable for salmon calcitonin
expression in yeast
<400> SEQUENCE: 2
tgttctaatt tgtctacttg tgttctaggt aaattatcac aagaattaca taaattgcag 60
acttatccaa gaaccaatac aggttcagga acacct 96
<210> SEQ ID NO 3
<211> LENGTH: 60
<212> TYPE: DNA
<213> ORGANISM: artificial
<220> FEATURE:
<223> OTHER INFORMATION: primer
<400> SEQUENCE: 3
tgtggtaatt tgtctacttg tatgttaggt acatataccc aagattttaa taaattccat 60
<210> SEQ ID NO 4
<211> LENGTH: 60
<212> TYPE: DNA
<213> ORGANISM: artificial
<220> FEATURE:
<223> OTHER INFORMATION: primer
<400> SEQUENCE: 4
aggtgcgcca actccaatag cagtttgtgg aaatgtatgg aatttattaa aatcttgggt 60
<210> SEQ ID NO 5
<211> LENGTH: 60
<212> TYPE: DNA
<213> ORGANISM: artificial
<220> FEATURE:
<223> OTHER INFORMATION: primer
<400> SEQUENCE: 5
tgttctaatt tgtctacttg tgttctaggt aaattatcac aagaattaca taaattgcag 60
<210> SEQ ID NO 6
<211> LENGTH: 60
<212> TYPE: DNA
<213> ORGANISM: artificial
<220> FEATURE:
<223> OTHER INFORMATION: primer
<400> SEQUENCE: 6
aggtgttcct gaacctgtat tggttcttgg ataagtctgc aatttatgta attcttgtga 60
<210> SEQ ID NO 7
<211> LENGTH: 32
<212> TYPE: PRT
<213> ORGANISM: Oncorhynchus gorbuscha
<300> PUBLICATION INFORMATION:
<301> AUTHORS: Martial, K., Maubras, L., Taboulet, J., Jullienne,
A., Milhaud,
G., Moukhtar, M.S. and Cressent, M
<302> TITLE: Production of salmon calcitonin I in Oncorhynchus gorbuscha
by alternative polyadenylation of two RNA species
<303> JOURNAL: Gene
<304> VOLUME: 149
<305> ISSUE: 2
<306> PAGES: 277-81
<307> DATE: 1994-11-18
<313> RELEVANT RESIDUES: (6)..(37)
<400> SEQUENCE: 7
Cys Ser Asn Leu Ser Thr Cys Val Leu Gly Lys Leu Ser Gln Glu Leu
1 5 10 15
His Lys Leu Gln Thr Tyr Pro Arg Thr Asn Thr Gly Ser Gly Thr Pro
20 25 30
|
Nucleic acid encoding recombinant salmon calcitonin, expression vector thereof, and method for producing recombinant salmon calcitonin therewith. The nucleic acid encoding recombinant salmon calcitonin comprises the sequence of SEQ ID No. 2
| 2
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This amendment claims priority under 35 USC § 119(e)(1) of provisional application number 60/074,949, filed Feb. 17, 1998.
TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to computer memories, and more particularly to a content addressable memory with reduced size, power, and access time and increased floor planning flexibility.
BACKGROUND OF THE INVENTION
Random access memory (RAM) is the memory most often used in current electronic systems. In a RAM, the address of data is provided on an address bus and the corresponding data is then retrieved. The width of the address bus determines how many memory locations can be addressed and thus determines the size of the memory.
Another type of memory is content addressable memory (CAM). In a CAM, the data itself is provided in a special register. The CAM is then searched for the data by comparing each bit of the data with each bit of the information stored in the CAM. If a match is found, a match flag is set to indicate that the data was found. A priority encoder then prioritizes the matching locations (if more than one match was found) and generates the corresponding address of the highest priority matching location. One application for the CAM is in a memory cache system in which the matching process is used to determine whether the cache includes data needed elsewhere, such as data requested by a processor.
Since the CAM is searched based on the contents of the memory location rather than based on the data location in the memory, and further, since the same data content may be found in more than one location in the CAM, the CAM is also useful in applications in which it is desirable to retrieve multiple items from memory simultaneously. The highly parallel nature of content addressing is also an advantageous feature useful, for example, in processing high level algorithmic functions. Use of the CAM in these types of applications, however, also generally requires much larger CAMs than typically used in a cache. For smaller CAMs such as those used in cache applications, a primary concern is fast, efficient access and thus, the focus is on optimizing the access method to minimize latency. In larger CAMs, however, where the objective is to support a large number of entries, attention must be focused on maintaining an efficient layout shape and a reasonable bandwidth.
FIG. 1 shows an architectural diagram of a prior art CAM array 100 . The prior art CAM array 100 consists of 1024 words, each word having 56 bits. Each row in the CAM array 100 represents one of the 1024 words. Each of the 56 columns in the CAM array 100 represents one bit in each of the 1024 words. Thus, as shown in the prior art CAM array 100 , a long, narrow memory structure is typically used. In systems which include a CAM array such as that shown in FIG. 1, the CAM array may be extended to increase memory capacity by adding more rows. This long, narrow structure, however, not only becomes increasingly cumbersome as more capacity is added but also severely impacts the layout of the floor plan of any device in which it is used.
Other prior art CAM systems do little to alleviate these types of problems. Most, such as the systems described in U.S. Pat. Nos. 4,888,731, 4,928,260, and 5,388,066, simply provide more efficient methods of storing data and/or accessing data stored in the CAM array while still utilizing the conventional long, narrow architecture. Another such prior art CAM system such as described in the article entitled “Extending The CacheCAM™ Comparand Width” by Ray Parry, published by Music Semiconductor, AB-N6, concatenates adjacent entries of the typical long, narrow CAM array structure using validity bits to identify successive entries.
What is needed is a simple, easy to implement method and system for managing a CAM having a large number of entries while still maintaining an efficient layout shape and a reasonable bandwidth.
SUMMARY OF THE INVENTION
The present invention is a content addressable memory (CAM) system, having a CAM array operable to store a number of data words, each of the data words having a number of bits. The CAM is made up of rows and columns of CAM cells, each CAM cell operable to store one of the bits of one of the data words. Each row of the CAM system of the present invention stores the bits of at least two of the data words. The bits of the at least two data words on a single row are interleaved. Using a time multiplexing technique, the CAM system of the present invention accesses each of the data words on the row in turn during one of a number of cycles.
In another aspect of the present invention, a portion of the content of the data words is used to determine where on the row the data word is stored and, thus, reduces the number of cycles required to search for a particular data word.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a memory storage structure of a prior art content addressable memory (CAM);
FIG. 2 is a block diagram illustrating a CAM system in accordance with the present invention;
FIG. 3 illustrates in detail an exemplary CAM array in accordance with the present invention;
FIG. 4 shows a detailed diagram of a CAM cell in accordance with the present invention; and
FIG. 5 is a detailed block diagram of a portion of the CAM system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 illustrates a CAM system 50 in accordance with the present invention. The CAM system 50 shown in FIG. 2 includes a CAM array 52 which, although other similarly proportioned dimensions can be used as will be understood from the description hereinbelow, is comprised of 57,344 CAM cells arranged in 256 rows and 224 columns. The CAM array 52 is bi-directionally coupled to a bit line controller 54 by 224 bit line pairs, each bit line pair connecting one of the columns of CAM cells in the CAM array 52 . The 224 bit line pairs are selectively enabled by the bit line controller 54 in one embodiment of the present invention in accordance with a 2-bit ‘column address’ signal and a ‘mode control’ signal. The ‘column address’ signal being provided by a cycle counter, not shown. In another embodiment of the present invention, the 224 bit line pairs are selectively enabled by the bit line controller 54 in accordance with the ‘column address’ signal, the ‘mode control’ signal and a 56-bit ‘data in’ signal. The 56-bit ‘data in’ signal provides data to be stored in or matched to data stored in the CAM array 56 . A 56-bit ‘data out’ signal returns data retrieved from the CAM array 52 .
The CAM array 52 is also connected to an address decoder 53 by 256 row select lines and to a priority encoder 58 by 256 match lines. The 256 row select lines are each connected to one row of CAM cells in the CAM array 52 which are selectively enabled in accordance with a 8-bit ‘row address in’ signal decoded by the address decoder 53 . The priority encoder 58 generates an 8-bit ‘address out’ signal to indicate the location in the CAM array 52 of matching data in accordance with the 256 match lines. Operation of the CAM system 50 is discussed in more detail hereinbelow.
The CAM system 50 of the present invention has three modes of operation as shown hereinbelow in Table 1. The three modes of operation, as indicated by the mode control signal, are data write, data read, and match. In the data write mode, the bit line controller 54 is operable to cause data to be written into selected CAM cells in the CAM array 52 in accordance with a row address provided by the ‘row address in’ signal, and a column address provided by the ‘column address in’ signal. Since multiple data words can be stored in each row of the CAM array 52 , the column address is used to determine which of the data words on the selected row to use. The content of the data word to be stored in the CAM array 52 is provided by the ‘data in’ signal.
In the data read mode, data is read from selected CAM cells in the CAM array 52 in accordance with a row address provided by the ‘row address in’ signal and a column address provided by the ‘column address in’ signal. The corresponding stored data word is then retrieved, passed to the bit line controller 54 and is then provided as output by the ‘data out’ signal.
In the match mode, target data, provided on the ‘data in’ signal is searched for in the CAM array 52 . A column address is again provided by the ‘column address in’ signal. The match operation is performed sequentially across selectively enabled ones of the columns using a time multiplexing technique, discussed in more detail hereinbelow. Indication of the match or matches found are provided to the priority encoder 58 . The resultant address of the highest priority matching data word, since multiple matches may be found, is provided by the priority encoder 58 using the ‘address out’ signal.
TABLE 1
Mode
Row
Column
Address
Control
Address In
Address In
Data In
Data Out
Out
Write
X
X
X
X
Read
X
X
X
X
Match
X
X
X
X
FIG. 3 illustrates an exemplary structure of the CAM array 52 used in the CAM system 52 in accordance with the present invention. Instead of having one 56 bit data word per row in the CAM array 52 , the CAM array 52 , as shown in detail in FIG. 3, includes four data words per row. Each data word has 56 bits which are interleaved with the bits of the other data words on the same row. Thus, as illustrated in FIG. 3, bit 0 of data word 0 (W 0 0 ) is adjacent to bit 0 of data word 1 (W 1 0 ). Bit 0 of data word 1 (W 1 0 ) is adjacent to bit 0 of data word 2 (W 2 0 ). Bit 0 of data word 2 (W 2 0 ) is adjacent to bit 0 of data word 3 (W 3 0 ). Bit 0 of data word 3 (W 3 0 ), since only four data words are shown in FIG. 3 by way of example, is then adjacent to bit 1 of data word 0 (W 0 1 ). As will be discussed in more detail hereinbelow in connection with the discussion of FIG. 5, interleaving the bits of each data word stored on a row provides for an efficient floor plan layout of the CAM array 52 .
This pattern of interleaving the bits of each data word continues until all bits of all data words on that row are represented. Although only four 56-bit data words are shown on each row in the exemplary CAM array 52 shown in FIG. 3, it is contemplated that any number of data words of any desired bit width may be used. The time multiplexing technique, discussed in more detail hereinbelow, for accessing the data words may be adjusted accordingly.
FIG. 4 shows a detailed diagram of a CAM cell 40 in accordance with the present invention. The CAM cell 40 includes a bit storage circuit which is operable to store one bit of one data word. The bit storage circuit is comprised of a pair of inverters 43 forming a flip-flop, the upper inverter's output determining memory output. Each inverter 43 has an input which is coupled to the other's output and to a pair of bit lines 41 by a corresponding normally-open transistor switch 105 which is controlled by a gate coupled to a row select line 44 . To write a bit to the CAM cell 40 , i.e., during a data write operation, the bit and its complement (BIT and {overscore (BIT)}) are set on the bit lines 41 , and a logical ‘1’ signal is placed on the row select line 44 to close the switches 45 .
The CAM cell 40 also includes a bit compare circuit which is operable to perform a comparison of the bit stored in the CAM cell 40 with a corresponding bit of a target data word, i.e., during a data match operation. The bit compare circuit is comprised of a three transistor comparator formed by transistors switches 47 and 49 . Each switch 47 is controlled by a gate coupled to the output of a corresponding inverter 43 and a source coupled to a corresponding row select line 41 . Switch 49 couples the switches 47 to the match line 46 and to ground.
The match line 46 is initially pre-charged to logical ‘1’ or HIGH. To compare a bit of the target data word to the bit stored in the CAM cell 40 , the target data bit and its complement are set on the bit lines 41 of the CAM cell 40 . The bit compare circuit generates a cell output signal which indicates the result of the comparison. If there is a mismatch between the bit stored in the CAM cell 40 and the target data bit, the cell output signal causes the match line 46 to discharged to ground through switch 49 . Otherwise, the bit compare circuit of that CAM cell 40 has no effect on the charge of the match line 46 .
All of the CAM cells 40 on the same row in the CAM array 52 share a common match line 46 and thus, during a match operation, the bit lines 41 apply all of the bits of the target data word in parallel to the selectively enabled CAM cells 40 in each row of the CAM array 52 . If any enabled CAM cell 40 has a mismatch, it discharges that row's match line 46 to ground. If, however, all of the bits of the enabled CAM cells 40 on a row match their corresponding bit in the target data word, the match line 46 for that row remains at logical ‘1’ or HIGH.
By the same token, all of the CAM cells 40 in one column in the CAM array 52 share a common pair of bit lines 41 . Each of the bit line pairs connects a column of CAM cells and provides each bit of the data word and its inverse to selected columns of CAM cells in the CAM array 52 for storage during the data write operation and provides the corresponding bit of the target data word and its inverse to selected columns of CAM cells for comparison during the match operation and accepts the bits of a stored data word retrieved as a result of the data read operation.
Thus, during a match operation, the bit lines 41 simultaneously apply each of the bits of a target data word in parallel to the selectively enabled CAM cells 40 of all rows. Any CAM cell in a row having a mismatch discharges its corresponding matchline 46 to logical ‘0’ or LOW, but a row having all matching CAM cells 40 maintains its match line 46 at logical ‘1’ or HIGH. By inputting all of the match lines 46 to an OR gate, not shown, the output of the OR gate provides a global match indicator signal, not shown, is provided for the CAM array 52 .
Returning to FIG. 2, since the CAM array 52 has four interleaved data words stored on each row in a first embodiment of the present invention, the CAM system 50 of the present invention uses four cycles to perform the match operation. By way of example, a first cycle is indicated when the ‘column address in’ signal has a value of ‘00’. A second cycle is indicated when the ‘column address in’ signal has a value of ‘01’. A third cycle is indicated when the ‘column address in’ signal has a value of ‘10’. And, a fourth cycle is indicated when the ‘column address in’ signal has a value of ‘11’.
During one of the four cycles indicated by the ‘column address in’ signal, the CAM controller simultaneously activates the CAM cells corresponding to data word 0 on each row. During a second of the four cycles, the bit line controller 54 simultaneously activates the CAM cells corresponding to data word 1 on each row. During a third of the four cycles, bit line controller 54 simultaneously activates the CAM cells corresponding to data word 2 on each row. Finally, during a fourth of the four cycles, the bit line controller 54 simultaneously activates the CAM cells corresponding to data word 3 on each row.
Thus, at least four cycles are required during the match operation to ensure either finding the target data word or determining that the target data word is not present in the CAM array 52 in that the bit line controller 54 is time multiplexed to provide the target data to only one of the four data words on each row during each cycle. Thus, only one of the four possible bit line pairs for each bit position (since four interleaved data words are stored on each row in the CAM array 52 ) is active during any one match cycle. The other three pairs of bit lines (which represent the same bit for the other three data words on the same row) are held LOW, at ‘00’. With both bit lines in the bit line pair (BIT and {overscore (BIT)}) held LOW, the compare circuit in the CAM cell does not operate and thus will not cause the match line to discharge. The four cycles are thus required to sequentially allow each of the four bit line pairs corresponding to a bit position of each of the four data words stored on a single row to be active while the others are inactive.
In a second embodiment of the CAM system 50 of the present invention, no more than two lookup operations are required to ensure either finding the target data word or determining that the target data word is not present in the CAM array 52 . In the second embodiment of the present invention, during the match operation, the bit line controller 54 is operable to supply the target data word to more than one of the data words on each row during each cycle. Thus, in the second embodiment of the CAM system 50 of the present invention, the mux factor is not the same as the mux factor in the first embodiment of the present invention.
In the second embodiment of the CAM system 50 of the present invention, the bit line controller 54 is operable to use some property of the target data word, e.g., the least significant bit or any other bit or the parity of any combination of bits, to determine in which of the data words on the selected row to store the data. If, for example, the parity of the least significant bit is used, then even data could be stored in data word 0 or in data word 1 and odd data could be stored in data word 2 or in data word 3 . Thus, only two cycles are required to locate the data during a match operation. If the target data is even, data word 0 is searched during the first cycle and data word 1 is searched in the second cycle. If the target data is odd, then data word 2 is searched in the first cycle and data word 3 is searched during the second cycle.
If the bit line controller 54 uses two bits of the data to determine in which data word on a selected row to store the data during the data write operation, then only one cycle is needed to search for data during the match operation. As an example, if the two least significant bits of the data are used to determine in which data word to store the data, then if the two least significant bits of the data are ‘00’, the data is stored in data word 0 , if the two least significant bits of the data are ‘01’, the data is stored in data word 1 , if the two least significant bits of the data are ‘10’, the data is stored in data word 2 , and if the two least significant bits of the data are ‘11’, the data is stored in data word 3 . By the same token, during the match operation, the two least significant bits in the target data are used to determine which data word on each row to search in the CAM array 52 . Thus, only one lookup cycle is required to search for the target data in the CAM array 52 .
FIG. 5 is a block diagram illustrating in more detail the control flow between the CAM array 52 and the bit line controller 54 . Using the exemplary CAM array 52 shown in FIG. 3 which stores four interleaved 56-bit data words on each row, FIG. 5 shows four columns and four rows of the CAM array 52 . In other words, FIG. 5 shows the CAM cells 40 for bit 0 of the four data words stored on each of four rows in the CAM array 52 . Bits 1 - 55 of the four data words, not shown, would be similarly structured for each row.
Also shown in FIG. 5 is a detailed portion of the bit line controller 54 . Included in the bit line controller 54 is a number of CMOS transmission gates 62 , each of which couples each bit D n and its complement {overscore (D n +L )} of a target data word to bit n and its complement {overscore (n)}, respectively, of each data word stored on a row of the CAM array 52 . In FIG. 5, D 0 and {overscore (D 0 +L )}, generated using inverter 68 , are shown connected to their respective CMOS transmission gates 62 through sense amps 64 .
Each of the CMOS transmission gates 62 shown in FIG. 5 are comprised of parallel n-channel and p-channel CMOS transistors. The n-channel side of each of the CMOS transmission gates 62 is connected to an enable signal, EN. The p-channel side of each of the CMOS transistors 62 is connected to the complement of the associated enable signal, {overscore (EN)}. There is one enable signal, EN, for each data word stored on a row in the CAM array 52 . Thus, in the exemplary CAM array 52 which has four data words stored on each row, there are four enable signals, EN 0 , EN 1 , EN 2 , and EN 3 , each of which corresponds to a particular data word. Thus, in the first embodiment of the present invention, assuming that when the column address signal has a value of ‘00’data word 0 (W 0 ) is selected, the bit line controller 54 sets enable signal EN 0 to logical ‘1’, or HIGH which activates all bit positions of data word 0 (W 0 0 through W 55 ), while the other three enable signals, EN 1 , EN 2 , and EN 3 , are set to logical ‘0’or LOW. In the second embodiment of the present invention, where some property of the target data word is used to determine which data word column to write to, read from or match to, the column address signals are generated by the bit line controller 54 using the selected property.
As can be seen in FIG. 5, by interleaving the bits of the data words stored on each row, a more efficient floor plan layout is achieved. The bit lines which provide exemplary data bit D 0 of the target data word can be located closely with the same bit of all the data words stored in the CAM array 52 , even though multiple data words are stored on each row.
OTHER EMBODIMENTS
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the arts in which the invention pertains. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.
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A content addressable memory (CAM) system ( 50 ) is disclosed which includes a CAM array ( 52 ) for storing an array of data words. More than one data word is stored on each row with the bits of the data word columns interleaved with each other. The CAM array ( 52 ) is accessed during one of several modes of operation in accordance with signals from a bit line controller ( 54 ) which activate certain ones of a plurality of bit lines coupling the bit line controller ( 54 ) to the CAM array ( 52 ). The modes of operation, as indicated by a mode control signal, include a write mode, a read mode and a match mode. In first embodiment of the present invention, the bit line controller ( 54 ) sequentially accesses each of the columns of data words by selectively activating certain of the bit lines in accordance with a column address signal and the mode control signal.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 USC 119 to U.S. Provisional Application No. 60/894,144, entitled, “HIGH DENSITY MAPPING CATHETER,” filed on Mar. 9, 2007, the contents of which are incorporated herein as if set forth in full.
BACKGROUND OF THE INVENTION
[0002] a. Field of the Invention
[0003] The present invention relates to electrical mapping of a patient's heart and, in particular, to a catheter that can quickly gather data for high resolution cardiac mapping and associated methodology.
[0004] b. Background
[0005] A number of mapping and navigation options have been developed to enable electrical mapping of a patient's heart as well as navigation of an instrument, such as an electrode catheter, to a desired site for ablation or other treatment. For example, the EnSite NavX® utility is integrated into the Ensite® Advanced Mapping System by St. Jude Medical, Inc., and provides non-fluoroscopic navigation of conventional electrophysiology catheters. The navigation methodology is based on the principle that when electrical current is applied across two surface electrodes, a voltage gradient is created along the axis between the electrodes. Although any suitable number of electrodes may be utilized, typically six surface electrodes are placed on the body of the patient and in three pairs: anterior to posterior, left to right lateral, and superior (neck) to inferior (left leg). The three electrode pairs form three orthogonal axes (X-Y-Z), with the patient's heart being at least generally at the center.
[0006] The noted six surface electrodes are connected to the Ensite® Advanced Mapping System, which alternately sends an electrical signal through each pair of surface electrodes to create a voltage gradient along each of the three axes, forming a transthoracic electrical field, Conventional electrophysiology catheters may be connected to the Ensite® Advanced Mapping System and advanced to the patient's heart. As a catheter enters the transthoracic field, each catheter electrode senses voltage, timed to the creation of the gradient along each axis. Using the sensed voltages compared to the voltage gradient on all three axes, the EnSite NavX® utility calculates the three-dimensional position of each catheter electrode. The calculated position for the various electrodes occurs simultaneously and repeats many times per second (e.g., about 93 times per second).
[0007] The Ensite® Advanced Mapping System displays the located electrodes as catheter bodies with real-time navigation. By tracking the position of the various catheters, the EnSite NavX® utility provides non-fluoroscopic navigation, mapping, and creation of chamber models that are highly detailed and that have very accurate geometries. In the latter regard, the physician sweeps an appropriate catheter electrode across the heart chamber to outline the structures by relaying the signals to the computer system that then generates the 3-D model. This 3-D model may be utilized for any appropriate purpose, for instance to help the physician guide an ablation catheter to a heart location where treatment is desired/required.
[0008] In order to generate an accurate and highly detailed map of a patient's heart, a large amount of data is required. Accordingly, an electrode catheter may be swept across various surfaces of the heart while obtaining data as described above. In order to accelerate this mapping data acquisition and/or increase the volume of data available for mapping, a number of high-density electrode catheters have been developed or proposed. Generally, these include a number of electrodes in an array in relation to a catheter body so as to substantially simultaneously obtain many mapping data points for a corresponding surface of cardiac tissue proximate to the catheter body. For example, these electrodes may be deployed along the length of a section of the catheter body that has a coil or other three-dimensional configuration so as to provide the desired spatial distribution of the electrodes. Alternatively, the electrodes may be disposed on a number of structural elements extending from a catheter body, e.g., in the form of a basket or a number of fingers. Work continues towards developing a high density mapping electrode catheter that achieves the goal of rapidly gathering mapping information while being safe in operation and simple in construction.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention is directed to a high density mapping catheter including a number of shape memory electrode fibers and associated methods of construction and operation. The invention ensures good electrical contact between a large number of mapping electrodes and cardiac tissue in relation to a number of cardiac tissue approach angles, including head-on approaches. In addition, the invention allows for a reduced range of deflection angles in relation to deployment and retraction of the electrode fibers, thereby reducing resistance to retraction and reducing stress on the fibers and associated concerns regarding patient safety. The catheter of the present invention allows for rapid acquisition of a large amount of mapping data and allows for a variety of different geometries in relation to sweeping of the catheter across the cardiac tissue.
[0010] In accordance with one aspect of the present invention, a high density mapping catheter includes a plurality of thin forwardly extending electrode fibers. In this regard, the catheter includes a catheter body and a number of electrode filaments/fibers that extend from the catheter body. Free ends of these fibers extend forwardly towards the distal tip of the catheter body. Each electrode fiber supports at least one electrode thereon. In one arrangement, such electrodes are disposed on the distal ends of the fibers.
[0011] In one arrangement, each electrode fiber is formed as an elongated body. In such an arrangement, each filament has a proximal end that is attached to the catheter body and a free distal end. In one arrangement, the fibers comprise a substantially cylindrical body in an undeflected state. In such an arrangement, an angle between a long axis of the cylindrical body and the longitudinal axis of the catheter body may be an acute angle. In one arrangement, such an acute angle is between about 30° and about 60°.
[0012] In one arrangement, the distal ends of at least a portion of the electrode fibers extend to an axial location that is beyond the distal tip of the catheter body. In this regard, when the distal tip of the catheter is advanced axially forward, one or more of the distal ends of the electrode fibers may contact patient tissue prior to the distal tip of the catheter body contacting such tissue. In a further arrangement, all the distal ends of the fibers extend beyond the distal tip of the catheter body. Furthermore, in such an arrangement, all the distal ends may be disposed in a substantially common plane.
[0013] In one arrangement, the electrode fibers may be formed of a shape memory fiber having a remembered shape. In such an arrangement, such a shape memory fiber may further include a conductive core, which may function as an electrical pathway for one or more electrodes supported by the electrode fiber. In such an arrangement, the fiber may further include an insulative coating disposed over an outside surface of at least a portion of the conductive core. Furthermore, in such an arrangement, the electrode(s) may be integrally formed with the conductive core.
[0014] In one arrangement, the diameter of the catheter body is at least five times the diameter of each individual electrode fibers. In a further arrangement, the diameter of the catheter body is at least 10 times the diameter of such fibers. Correspondingly, each individual fiber may be no greater than about 0.006 inches in diameter or no greater than about 0.004 inches in diameter. In a further arrangement, an electrode disposed on the distal ends of the fibers may have a diameter that is greater than the diameter of the fiber supporting the electrode.
[0015] The fibers may be spaced about the circumference of the electrode body. In this regard, such spacing may be random or predetermined. In one arrangement, the plurality of fibers are disposed in at least three axial rows disposed around the circumference of the catheter. In any arrangement, the individual fibers may be staggered to reduce the likelihood of shorting when the fibers are deflected. Electrode fibers may in one arrangement each have a common length. In another arrangement, different electrode fibers attached to the catheter body may have different lengths.
[0016] In accordance with one aspect of the present invention, a high density mapping catheter is provided that utilizes thin electrode fibers. The catheter includes a catheter body and a number of fibers extending from the catheter body. The fibers have a width, along at least a portion of the length thereof that is no more than about 0.006 of an inch. In one implementation, fibers having a width of about 0.002 of an inch are utilized. At least one electrode is supported on each of the fibers for use in acquiring mapping information. For example, an electrode may be disposed at the tip of the fiber. In one embodiment, the fibers are formed from conductive core shape memory alloy wires. The electrode can be formed as a ball of the core material at the end of the fiber.
[0017] In accordance with another aspect of the present invention, high density mapping catheter includes a large number of electrode fibers. More specifically, the catheter includes a catheter body and at least about 16 electrode fibers extending from the catheter body. Each of the electrode fibers includes at least one electrode for use in acquiring mapping information. In this manner, a large amount of mapping information can be rapidly acquired, and mapping information can be acquired in connection with a variety of catheter/tissue geometries.
[0018] In accordance with yet another aspect of the present invention, different length electrode fibers are used in connection with a high density mapping catheter. The catheter includes a catheter body and a number of mapping electrode elements extending from the catheter body, where each of the elements is formed from a conductive core shape memory fiber. The elements include a first element and a second element where the first element has a length different than that of the second element. For example, such differing lengths may allow for a desired spatial configuration of the tip electrodes of the various fibers when unconstrained.
[0019] In accordance with another aspect of the present invention, a method is provided for use in constructing a high-density mapping catheter. The method involves providing a shape memory fiber with a conductive core. An end portion of the shape memory material of the fiber is then stripped back to expose the conductive core. The exposed portion of the conductive core can then be melted to form a generally spherical tip electrode. For example, the core may be melted by a laser or by exposure to another heat source. This allows for simple construction of electrode fibers having an enlarged rounded tip. Such a tip shape is desirable to avoid puncturing tissue and to enhance visibility of the tip electrodes in relation to various visualization modalities.
[0020] In accordance with a further aspect of the present invention, a method is provided for use in mapping cardiac tissue. The method includes the steps of: providing an electrode catheter, including a catheter body with a number of electrode elements extending therefrom, where each of the element is formed from a shape memory fiber having a conductive core, and the electrode catheter further includes a sheath; introducing the electrode catheter into a chamber of a patient's heart to be mapped; extending the catheter body from the sheath such that the mapping electrode elements extend from the catheter body in a mapping configuration; and sweeping the mapping electrode elements across a cardiac surface. The noted method allows for acquisition of a large volume of mapping information in a short time.
[0021] In accordance with another aspect of the present invention, a further method for use in mapping cardiac tissue is provided. The method involves providing an electrode catheter including a catheter body having a tip electrode disposed on a distal end thereof and a number of mapping electrode elements extending from the catheter body. Each of the mapping electrode elements is formed from a shape memory fiber having a conductive core. The method further involves operating a number of the mapping electrode elements, disposed circumferentially around the catheter tip electrode to obtain position information, and substantially simultaneously operating the catheter tip electrode to perform a desired medical procedure. For example, the catheter tip electrode may be a mapping electrode, and the medical procedure may involve mapping using the catheter tip electrode and the mapping electrode elements. Alternatively, the catheter tip electrode may be an ablation electrode, and the desired medical procedure may be an ablation procedure. In this regard, the mapping electrode elements may be used to guide the ablation electrode to the desired site or locus of ablation points.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a schematic diagram of a navigation and mapping system in accordance with the present invention.
[0023] FIG. 2 illustrates a catheter constructed in accordance with the present invention being introduced into a patient's heart.
[0024] FIG. 3 illustrates a display provided by a navigation and mapping system in accordance with the present invention.
[0025] FIGS. 4-6F illustrate various embodiments of a high density mapping catheter in accordance with the present invention.
[0026] FIGS. 7A-7C illustrate operation of a high density mapping catheter in accordance with the present invention.
[0027] FIGS. 8A-8C illustrate construction of an electrode fiber for use in a high density mapping catheter in accordance with the present invention.
[0028] FIGS. 9A-9C show a high density mapping catheter with curved electrode fibers in accordance with the present invention.
DETAILED DESCRIPTION
[0029] FIG. 1 presents a schematic of one embodiment of a medical navigation/visualization system 5 . The medical navigation/visualization system 5 will be briefly addressed herein, as it is one such system that may utilize the mapping electrode functionality that will be addressed in detail below. The medical navigation/visualization system 5 is also discussed in detail in U.S. Patent Application Publication No. US 2004/0254437, that is entitled “METHOD AND APPARATUS FOR CATHETER NAVIGATION AND LOCATION AND MAPPING IN THE HEART,” that published on Dec. 16, 2004, that is assigned to the assignee of this patent application, and the entire disclosure of which is incorporated by reference in its entirety herein.
[0030] The patient 11 is only schematically depicted as an oval for clarity. Three sets of surface or patch electrodes are shown as 18 , 19 along a Y-axis; as 12 , 14 along an X-axis; and 16 , 22 along a Z-axis, Patch electrode 16 is shown on the surface closest to the observer, and patch electrode 22 is shown in outline form to show its placement on the back of patient 11 . An additional patch electrode, which may be referred to as a “belly” patch, is also seen in the figure as patch electrode 21 . Each patch electrode 18 , 19 , 12 , 14 , 16 , 22 , 21 is independently connected to a multiplex switch 24 . The heart 10 of patient 11 lies between these various sets of patch electrodes 18 , 19 , 12 , 14 , 16 , 22 . Also seen in this figure is a representative catheter 13 having a number of electrodes 17 . The electrodes 17 may be referred to as the “roving electrodes” or “measurement electrodes” herein. In the embodiments described below, many electrodes on fiber elements are used for high-density mapping. It should be appreciated that in use the patient 11 will have most or all of the conventional 12 lead ECG system in place as well, and this ECG information is available to the system although not illustrated in the figure.
[0031] Each patch electrode 18 , 19 , 12 , 14 , 16 , 22 , 21 is coupled to the switch 24 , and pairs of electrodes 18 , 19 , 12 , 14 , 16 , 22 are selected by software running on computer system 20 , which couples these electrodes 18 , 19 , 12 , 14 , 16 , 22 to the signal generator 25 . A pair of electrodes, for example electrodes 18 and 19 , may be excited by the signal generator 25 and they generate a field in the body of the patient and the heart 10 . During the delivery of the current pulse, the remaining patch electrodes 12 , 14 , 16 , 22 are referenced to the belly patch electrode 21 , and the voltages impressed on these remaining electrodes 12 , 14 , 16 , 22 are measured by the analog-to-digital or A-to-D converter 26 . Suitable lowpass filtering of the digital data may be subsequently performed in software to remove electronic noise and cardiac motion artifact after suitable low pass filtering in filter 27 . In this fashion, the various patch electrodes 18 , 19 , 12 , 14 , 16 , 22 are divided into driven and non-driven electrode sets. While a pair of electrodes is driven by the signal generator 25 , the remaining non-driven electrodes are used as references to synthesize the orthogonal drive axes.
[0032] The belly patch electrode 21 is seen in the figure is an alternative to a fixed intra-cardiac electrode. In many instances, a coronary sinus electrode or other fixed electrode in the heart 10 can be used as a reference for measuring voltages and displacements. All of the raw patch voltage data is measured by the A-to-D converter 26 and stored in the computer system 20 under the direction of software. This electrode excitation process occurs rapidly and sequentially as alternate sets of patch electrodes 18 , 19 , 12 , 14 , 16 , 22 are selected, and the remaining members of the set are used to measure voltages. This collection of voltage measurements may be referred to herein as the “patch data set”. The software has access to each individual voltage measurement made at each individual patch electrode 18 , 19 , 12 , 14 , 16 , 22 during each excitation of each pair of electrodes 18 , 19 , 12 , 14 , 16 , 22 .
[0033] The raw patch data is used to determine the “raw” location in three spaces (X, Y, Z) of the electrodes inside the heart 10 , such as the roving electrodes 17 . The patch data set may also be used to create a respiration compensation value to improve the raw location data for the locations of the electrodes 18 , 19 , 12 , 14 , 16 , 22 .
[0034] If the roving electrodes 17 are swept around in the heart chamber while the heart 10 is beating, a large number of electrode locations are collected. These data points are taken at all stages of the heartbeat and without regard to the cardiac phase. Since the heart 10 changes shape during contraction, only a small number of the points represent the maximum heart volume. By selecting the most exterior points, it is possible to create a “shell” representing the shape of the heart 10 . The location attribute of the electrodes within the heart 10 are measured while the electric field is impressed on the heart 10 by the surface patch electrodes 18 , 19 , 12 , 14 , 16 , 22 .
[0035] FIG. 2 shows a catheter 13 , which may be a high-density mapping catheter, as described in more detail below, in the heart 10 . The catheter 13 has a tip electrode 51 and additional electrodes 52 . Since these electrodes 51 and 52 lie in the heart 10 , the location process detects their location in the heart 10 . While they lie on the surface and when the signal generator 25 is “off”, each patch electrode 18 , 19 , 12 , 14 , 16 , 22 ( FIG. 1 ) can be used to measure the voltage on the heart surface. The magnitude of this voltage, as well as the timing relationship of the signal with respect to the heartbeat events, may be measured and presented to the cardiologist through the display 23 . The peak-to-peak voltage measured at a particular location on the heart wall is capable of showing areas of diminished conductivity, and which may reflect an infracted region of the heart 10 . The timing relationship data are typically displayed as “isochrones”. In essence, regions that receive the depolarization waveform at the same time are shown in the same false color or gray scale.
[0036] FIG. 3 shows an illustrative computer display from the computer system 20 . The display 23 is used to show data to the physician user and to present certain options that allow the user to tailor the system configuration for a particular use. It should be noted that the contents on the display 23 can be easily modified and the specific data presented is only of a representative nature. An image panel 60 shows a geometry of the heart chamber 62 that shows “isochrones” in false color or grayscale together with guide bar 64 to assist in interpretation. In this hypothetical image, the noted mapping methodology has been used with a high-density catheter to create a chamber representation that is displayed as a contoured image.
[0037] The guide bar 64 is graduated in milliseconds and it shows the assignment of time relationship for the false color image in the geometry. The relationship between the false color on the geometry image 62 and the guide bar 64 is defined by interaction with the user in panel 66 . As shown, the display may also provide traces and other information related to the ECG electrodes, mapping electrodes and reference electrodes, as well as other information that may assist the physicians.
[0038] As noted above, a significant amount of data is required to generate a detailed image of the cardiac tissue of interest. In order to gather adequate data more quickly, it is desirable to provide a high density mapping electrode catheter having a plurality of electrodes. Once such catheter in accordance with the present invention is illustrated in FIGS. 5A and 5B . The illustrated catheter 500 includes a catheter body or shaft 502 having an electrode tip 508 disposed at a distal end thereof. The catheter 500 further includes a number of mapping electrode fibers 504 extending from the catheter shaft 502 . Each of the illustrated mapping electrode fibers 504 terminates in a tip electrode 506 . The electrodes 506 and 508 can be used to map cardiac tissue, as discussed above. More specifically, a physician can sweep the electrodes 506 and 508 across tissue to be mapped. In this regard, a large volume of mapping information can be obtained quickly due to the large number of electrodes 506 and 508 that can be maintained in contact with the tissue as the catheter 500 is swept across the tissue.
[0039] As will be described in more detail below, each of the mapping electrode fibers 504 may be formed from a shape memory fiber with a conductive core. For example, the fibers may be formed from a nickel titanium shaped memory fiber such as Nitinol with a conductive metallic core such as platinum. In addition, the fibers may be coated with an insulating material, e.g., Polyimide, to prevent shorts. The conductive core of the illustrated fibers 504 serves as the electrical pathway for the tip electrodes 506 . In addition, the tip electrodes 506 may be formed, as discussed below, by melting an exposed section of the conductive core. Alternatively, the tip electrodes may be formed separately and then tightly secured to the fibers.
[0040] Each of the electrode fibers 504 may be threaded through an inner lumen of the catheter shaft 502 . The fibers 504 then extend through holes formed in the catheter shaft 502 at the desired location. As is well known, shape memory materials such as Nitinol can be processed to remember a desired shape. When the shape memory materials are deflected from this remembered shape, the shape memory properties of the material tend to return the material to the remembered shape. In this case, the fibers 504 are processed to extend outwardly and forwardly from the catheter shift when unconstrained. The fibers may be bonded to the shaft 502 at the openings or may be maintained in a substantially fixed relationship with respect to the shaft 502 due to the configuration of the fibers 504 . In one construction implementation, platinum core Nitinol fibers with a Polyimide coating are threaded through the inner lumen of the catheter shaft 502 . The distal ends of the fibers are then pulled through openings in the catheter shaft, and a desired length of the fiber is pulled through the opening. The fibers are then processed to remember a particular configuration in relation to the angle formed between the catheter shaft 502 and the extending fibers 504 , as will be discussed in more detail below. Thereafter, a first length of the Polyimide coating and a second length of the Nitinol material are stripped from the end of the fibers to expose a portion of the platinum core. This platinum core is then melted to form a general spherical electrode tip 508 . It will be appreciated that other production sequences are possible. For example, the electrodes need not be integrally formed.
[0041] Generally, the catheter shaft 502 will have a diameter and stiffness that is significantly greater than the diameter and stiffness of the individual fibers 504 . For instance, the catheter shaft 502 may be a 5 or 7 French (i.e., 0.065 in. or 0.092 in.) catheter. In such embodiments, the catheter shaft may have a diameter that is at least five to ten times (or more) the diameter of the individual fibers. Such a difference in the relative sizes of the fibers 504 and the catheter shaft 502 may allow the fibers 504 to readily deflect when they are moved (e.g., brushed) over an internal tissue surface without significant deflection of the catheter shaft. For instance, each individual fiber may have a buckle strength (e.g., where bending is initiated) of no more than about 5 grams and more preferably no more than about 1-2 grams. Use of such low buckling strength allows the ends of the fibers 504 to readily conform to a tissue surface without significantly deflecting or otherwise penetrating the tissue surface. In contrast, when the catheter shaft contacts such an internal tissue surface, the stiffness of the shaft alerts an operator (e.g., physician) that the catheter shaft is in contact with patient tissue.
[0042] The inner lumen of the catheter shaft 502 may also be used to thread wiring for the tip electrode 508 . In addition, for certain procedures, it may be desired to irrigate the electrodes 506 and/or 508 with saline solution, for example, to prevent undesired heating or clotting. A lumen for such irrigation fluid may be formed within catheter shaft 502 (which can include openings to allow for flow of the irrigation fluid), or the irrigation fluid may be delivered via a separate lumen associated with other structure of the catheter.
[0043] The tip electrode 508 can be any of various types of electrode tips including an ablation tip or a mapping tip. The illustrated electrode tip 508 is a mapping tip, as best shown in FIG. 4 . The mapping tip 508 is divided into a number of electrically isolated sections 510 , in this case, defining four quadrants. Because the sections 510 are electrically isolated, independent positioning signals can be obtained with regard to each of the sections 510 . In this manner the signals from the sections 510 can be processed to define references, e.g., North, South, East and West, which are useful in guiding movement of the catheter during a medical procedure. It will be appreciated in this regard that it may be useful to press the catheter tip directly into cardiac tissue in a head-on configuration. In this regard, it is advantageous to configure the electrode fibers 504 in a forwardly extending configuration, as illustrated in FIGS. 5A and 5B , so as to obtain positioning data from a number of electrodes that are circumferentially disposed in relation to the tip electrode 508 . Similar advantages are obtained in relation to guidance of the tip electrode in ablation applications.
[0044] While the catheter 500 of FIGS. 4-5B thus represents an advantageous implementation of the present invention, it will be appreciated that many other implementations are possible. Some examples in this regard are illustrated in FIGS. 6B-6F . Referring first to FIG. 6A , the illustrated catheter 600 includes a catheter shaft 602 having an electrode tip 608 at a distal end thereof. In this case, the catheter 600 includes four mapping electrode fibers 604 formed from conductive core shape memory fibers, as described above. When unconstrained, each of the electrode fibers 604 extends outwardly and forwardly from the catheter shaft 602 so as to define an angle θ therebetween. A number of factors may be considered in determining a value of θ for a particular application. Some of these factors include the following:
[0045] 1. The angle θ may be selected to provide a desired lateral spacing of the electrode tips 606 for a given length of the electrode fibers 604 extending from the shaft 602 ;
[0046] 2. The angle θ is preferably greater than zero but less than 90 degrees in order to provide the desired forwardly extending configuration; and
[0047] 3. The angle θ may be selected to allow the fibers 604 to be retracted within a sheath and extended therefrom without undue resistance or stress on the fibers 604 .
[0048] It will be appreciated that other factors may be considered in this regard. In the illustrated embodiment, the angle θ is preferably between about 30 degrees and 60 degrees, for example, about 45 degrees. It will be appreciated that different angles may be used for different fibers if desired.
[0049] FIG. 6B shows an embodiment of a catheter 610 where a larger number of fibers 614 extend from the catheter shaft 612 . In addition, the illustrated fibers 614 are configured in a number of rows at different distances from the distal end of the shaft 612 . The fibers 614 in adjacent rows may be staggered so as to reduce the likelihood of shorts due to contact between electrode tips 616 S. In the embodiment of FIG. 6B (as well as that of FIG. 6A ), the tip electrodes 616 are arranged in a generally planar configuration slightly forward of the tip electrode 618 when unconstrained. It will thus be appreciated that the fibers 614 of different rows have different lengths. Such a configuration may be desirable in order to promote good contact by as many tip electrodes 616 as possible in relation to a head-on approach to cardiac tissue. That is, in connection with axial advancement of the shaft 612 towards cardiac tissue, it is expected that the tip electrodes 616 will first come into contact with the tissue. As advancement of the shaft 612 progresses, the fibers 616 deflect slightly to allow contact of the tip electrode with the tissue. Due to the shape memory properties of the fibers 614 , the tip electrode 616 will then be urged into good contact with the tissue and can accommodate a range of tissue contours. In addition, FIG. 6B also shows use of an optional webbing 613 that extends between adjacent fibers. Such webbing may be formed of a thin elastomeric material and provides a redundancy means for retaining an electrode fiber connected to the catheter shaft 612 in the event that the proximal end of the fiber 614 were to become disconnected from the catheter shaft 612 .
[0050] FIG. 6C shows a further alternative embodiment of a catheter 620 in accordance with the present invention. In this case, a number of electrode fibers 624 extend from the catheter shaft 622 at different positions along the length of the catheter shaft 622 . Again, fibers 624 of adjacent rows may be staggered, as discussed above. However, in this case, the tip electrodes 626 do not define a planar configuration. Rather, some of the tip electrodes 626 extend beyond the tip electrode 628 of the catheter shaft 622 , but others do not. Thus, the illustrated catheter 620 provides good mapping electrode contact for head-on approaches to cardiac tissue but also provides good contact in cases of dragging the catheter 620 across cardiac tissue with a side surface of the shaft 622 laying on the cardiac tissue as may be desired or otherwise occur. Moreover, in this configuration, there is a reduced likelihood of shorts due to contact between electrode tips 626 . It should be noted that any such shorts are not hazardous as the tip electrodes 626 are essentially receiving electrodes. Moreover, such shorts can be readily recognized and disregarded by the mapping processing logic. Nonetheless, avoiding such shorts enhances the amount of data that can be acquired.
[0051] In certain embodiments described above, the mapping tip electrodes were shown and described as defining a planar configuration when unconstrained. In some cases, a different special configuration may be desired. For example, when the catheter is expected to be deployed against a concave cardiac wall surface, a complementary spatial configuration (i.e., convex) of the tip electrodes may be desired. Conversely, when it is expected that the catheter will be deployed against a convex surface, a concave special configuration of the tip electrodes may be desired. FIGS. 6D and 6E illustrate concave and convex configurations of the tip electrodes 636 and 646 in this regard.
[0052] In connection with certain embodiments above, the mapping electrode fibers have been described as being configured in rows in relation to the length of the catheter shaft. It will be appreciated that it is unnecessary to deploy the electrode fibers in rows. This is illustrated in FIG. 6F . There, the illustrated catheter 650 includes a number of electrode fibers 654 terminating in fiber end 656 . The illustrated fibers 654 extend from the catheter shaft 652 at various locations along the shaft 652 , but they are not arranged in rows defined by a common location along the length of the shaft 652 . Similar to certain embodiments above, some of the tip electrodes 656 extend beyond the tip electrode 658 , but others do not. Moreover, different ones of the fibers 654 may extend different lengths from the shaft 652 .
[0053] As a further alternative, the electrode fibers may be cured rather than straight. This is generally shown in FIGS. 9A-9C . The illustrated catheter includes a core 900 with a number of curved electrode fibers 904 extending therefrom. Each of the electrode fibers 904 terminates in a tip electrode 9 - 6 as discussed above. The catheter is delivered to the procedure site in an introducer or sheath 902 .
[0054] In the illustrated embodiment, each of the electrode fibers 904 has a slightly convex curve. When the core 900 is retracted into the sheath 902 , as shown in section 9 B, the tip electrodes extend inwardly from the sheath 902 . This is best seen in the enlarged view of FIG. 9C . This reduces concerns about the enlarged tip electrode 906 snagging on the end of the sheath 902 .
[0055] As discussed above, the electrode fibers preferably extend outwardly and forwardly in relation to the catheter shaft. A number of advantages associated with this geometry were noted above. A further advantage is illustrated with reference to FIGS. 7A-7C , which also illustrate the operation of the mapping catheter. As shown in FIG. 7A , as the catheter 700 is threaded through a vessel of a patient to the patient's heart, the catheter shaft 702 and electrode fibers 704 may be in a retracted configuration in relation to a sheath 706 . It will be appreciated that this provides a compact profile, which facilitates passage of the catheter through the patient's vessel. Once the catheter has reached the desired site for medical procedure, the catheter shaft 702 can be advanced in relation to the sheath 706 , as shown in FIG. 7B .
[0056] Once the electrode fibers 704 extend beyond the end of the sheath 706 and are unconstrained, they spring into the deployed configuration due to the operation of the shape memory alloy. When the procedure is completed, the catheter shaft 702 can be retracted back into the sheath 706 , as shown in FIG. 7C . As this occurs, the electrode fibers 704 deflect and are constrained by the sheath 706 . It will be appreciated that the forwardly extending configuration of the fibers 704 facilitates the deployment and retraction of the catheter shaft 702 , as shown in FIGS. 7A-7C . In particular, the forwardly extending configuration reduces the resistance of the fibers to retraction of the shaft 702 . Moreover, the angular range of deflection associated with advancement and withdraw of the shaft 702 in relation to the sheath 706 is minimized. This reduces stress to the fibers 704 .
[0057] FIGS. 8A-8C illustrate a process for forming an electrode fiber as utilized in the various embodiments described above. In particular, it is desirable to provide an enlarged, generally spherical tip electrode in connection with the electrode fibers. This tip electrode configuration has a number of advantages. First, it is desirable to avoid puncturing of the cardiac tissue in connection with contact by the mapping electrodes. The enlarged and rounded configuration of the tip electrodes in this regard provides a larger surface contact area and reduces the pressure on and likelihood of puncturing any cardiac tissue contacted. In addition, it is desirable to enhance the visibility of the tip electrodes, both on the mapping display and in connection with any fluoroscopic images obtained in connection with the procedure. The enlarged tip electrode improves impedance and, therefore, visibility with respect to the electrical navigation system. The increased cross-section also improves visibility with respect to the fluoroscopic images.
[0058] Referring to FIGS. 8A-8C , the electrode fibers may be formed from commercially available conductive core shape memory fibers. For example, the electrode fibers may be formed from platinum core nickel titanium fibers. Such a commercially available fiber is illustrated in FIG. 8A . The fiber 800 includes a conductive core 802 that may be formed, for example, from a metallic conductor such as platinum. The core is surrounded by a tube of shape memory alloy material 804 such as a nickel-titanium material. An insulating coating 806 may be provided around the shape memory alloy 804 (which is also conductive).
[0059] To form the electrode fiber, the shape memory alloy material 804 and insulative coating 806 are stripped back from the distal end 808 of the fiber 800 . More specifically, the shape memory material is stripped back a distance L 1 , and the insulating coating 806 is striped back a distance L 2 that is greater than the distance L 1 . This leaves a length of L 3 where the shape memory material 804 is exposed. In one embodiment, the distance L 3 is between about 0.020 and 0.060 of an inch, for example, 0.040 of an inch.
[0060] The exposed core 802 is then melted to form a generally spherical tip electrode 810 , as shown in FIG. 8C . For example, a laser may be used to melt the core, or the core may be exposed to another heat source. The result is a tip electrode 8110 that has a diameter or width w 2 that is greater than the width w 1 of the fiber 800 . In this regard, the fiber preferably has a width w 1 of between about 0.002 to 0.006 of an inch, for example, 0.002 of an inch. The tip electrode 810 has a width w 2 of between about 0.003 and 0.012 of an inch, for example, 0.006 of an inch. This fiber, in combination with the geometries described above, provides a suitable stiffness or resistance to retraction of the catheter shaft into the sheath. That is, there is not undue resistance or stress on the electrode fibers.
[0061] The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. 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 various modifications required by the particular application(s) or use(s) of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.
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The present invention is directed to a high density mapping catheter including a number of shape memory electrode fibers and associated methods of construction ad operation. The invention ensures good electrical contact between a large number of mapping electrodes and cardiac tissue in relation to a number of cardiac tissue approach angles, including head-on approaches. In addition, the invention allows for a reduced range of deflection angles in relation to deployment and retraction of the electrode fibers, thereby reducing resistance to retraction and reducing stress on the fibers and associated concerns regarding patient safety. The catheter of the present invention allows for rapid acquisition of a large amount of mapping data and allows for a variety of different geometries in relation to sweeping of the catheter across the cardiac tissue.
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FIELD OF THE INVENTION
The invention relates to methods and apparatus for use with a tape cartridge associated with a printer to determine halt of tape feed from a supply reel to a take-up reel of the printer. More particularly, the invention relates to methods and apparatus for detecting tape breakage or end of tape feed.
BACKGROUND
In conventional tape cartridges for printers and typewriters and the like, the end of tape feed can be sensed by detecting the passage of a reflective element at the end of the tape past a sensor. At such time a reflective pulse is produced from a light source and the sensor acts to produce an electrical signal which halts the drive of the tape and carrier.
As disclosed in U.S. Pat. No. 4,115,013, a sensor can be fixed on the body of a carrier and the cartridge can be provided with an opening into which the sensor fits when the cartridge is mounted on the carrier. The position of the sensor is such that the light source projects a beam on the tape and at the end of tape feed, and a reflective element comes into a position where it reflects the light back to the sensor to generate a signal which halts the tape feed and printer.
This conventional system is effective and reliable and has found widespread usage. However, it has the deficiency that if the tape breaks, the tape drive continues and the printer operates without producing any printing due to the absence of a tape supply.
According to another known system, a mechanical flag is oscillated as the tape supply reel rotates and the flag is positioned between a light source and a sensor. Hence, as the supply reel continues to rotate, an intermittent pulse is produced by the sensor to indicate such continuous rotation. In the absence of a continuous train of pulses, the drive is halted.
This system has the advantage that if there is a break in the tape, the drives of the carrier and tape will be halted. However, the system has the disadvantage of using mechanical connections which are detrimental to the smooth rotation of the supply reel and can lead to breakdowns.
In another system, the opaque tape passes between a light source and a receiver to block passage of light therebetween and, at the end of the tape, a transparent portion is provided so that light can pass from the source to the receiver. Hence, at the end of the tape, a signal is produced to halt the tape feed and carrier drive. Should the tape break downstream of the light source and receiver, the carrier drive will continue to operate as will the tape feed despite the fact that no tape is being fed. If the tape breaks upstream of the light source and receiver, the loose length of tape will continue to be pulled by the tape feed until it passes through the light source and receiver whereupon the tape feed and carrier drive will be halted. This system lacks certainty in detecting tape breakage and unless breakage takes place precisely at the light source and receiver (a highly unlikely occurrence), either there will be no detection (downstream breakage) or there will be a lengthy delay in the detection (upstream breakage).
SUMMARY OF THE INVENTION
An object of the invention is to provide a method and apparatus by which continuous rotation of the supply reel can be detected without mechanical contact with the supply reel.
A further object of the invention is to utilize the sensed rotation of the supply reel to determine continuous feed of tape and, in the event of interruption of tape feed, to halt the printing operation.
In accordance with the above and further objects of the invention, there is provided apparatus for use with a tape cartridge for a printer to determine halt of tape feed from a supply reel to a take-up reel of the printer, said apparatus comprising first means on one of the reels for undergoing rotation therewith and second means fixed in position to face said first means to cooperate with said first means without mechanical contact therewith for producing electrical output pulses as said first means rotates with said one reel. A third means is coupled to the second means for determining halting of rotation of said one reel and consequent halting of tape feed upon cessation of said output pulses.
In accordance with a feature of the invention, the first means comprises alternate reflective and non-reflective portions and the second means is a sensor which produces a train of electrical output pulses in accordance with the periodic reflection to the sensor from the reflective portion as it passes the sensor.
In a preferred embodiment, the reflective and nonreflective portions are in the form of radial stripes directly applied to the bottom of the supply reel. This produces a train of pulses in the sensor which establishes that the supply reel is rotating and, hence, the tape is being fed. Upon tape breakage or when the tape stops its feed at the end of the tape, the train of pulses ceases and the drive is halted.
In order to avoid instability at the end of feed of tape from the supply reel, a further object of the invention is to positively lock the supply reel at the end of tape feed. This can be achieved advantageously by sensing increased tape tension at the end of feed of the tape.
The invention will be described in detail below with reference to specific embodiments thereof as illustrated in the attached drawing.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWING
FIG. 1 is a top plan view, partly broken away, of a tape cartridge for a printer according to one embodiment of the invention.
FIG. 2 is a bottom plan view, partly broken away, of the tape cartridge.
FIG. 3 is a front elevational view, partly broken away, of a portion of the cartridge installed on a carrier of the printer.
FIG. 4 is a schematic circuit diagram illustrating the operation of the apparatus of the invention.
FIG. 5 is an enlarged view of a detail of the cartridge of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawing there is seen a tape cartridge 1 generally made of molded plastic which contains a supply reel 2 and a take-up reel 3. The cartridge 1 is mounted on a carrier 4 of a printer which transports the cartridge 1 during the printing operation. The tape T is unwound from the supply reel 2 by driving a capstan C and the take-up reel 3 as the carrier 4 is transported during the printing operation. The drive of the carrier 4 and of capstan C and the take-up reel 3 is well-known in the art and requires no further explanation hereat since it does not form any part of the present invention.
Conventionally, in one known arrangement, when all of the tape has been unwound from the supply reel, a reflective element at the end of the tape travels past a sensor which receives reflected light from the reflective element and produces a signal to halt the drive of the carrier. A fresh cartridge is then placed on the carrier and printing is resumed.
Since the halting of the drive occurs only at the end of the tape when the sensor receives a reflected pulse from the reflective element, the system is unable to detect tape breakage and, in such case, the printing operation proceeds as if tape is being fed from the supply reel to the take-up reel. Accordingly, the machine keeps printing but no copy is made since tape feed is interrupted.
In another known embodiment, a transparent portion is provided at the end of the tape and the otherwise opaque tape passes between a light source and a receiver to block light passage therebetween. At the end of the tape, the transparent portion permits light to pass to the sensor to halt the drive of carrier. If the tape breaks downstream of the light source and receiver, the carrier drive and the drive of capstan will continue to operate despite the fact that no tape is being fed. If the tape breaks upstream of the light source and receiver, the loose length of tape will continue to be pulled by the tape feed until it passes through the light source and receiver whereupon the capstan C and carrier drive will be halted. This system lacks certainty in detecting tape breakage and unless breakage takes place precisely at the light source and receiver (a highly unlikely occurrence) either there will be no detection (downstream breakage) or there will be a lengthy delay in the detection (upstream breakage).
The invention provides for a system by which both end of tape and tape breakage are detected rapidly without any mechanical contact with the reels 2 and 3. In particular, as seen in FIG. 2, the bottom of the supply reel 2 is provided with a succession of alternate reflective and non-reflective portions 5 and 6 respectively. Mounted within a cavity 7 in the carrier 4 is an assembly 8 which comprises a light emitting diode 9 and a light sensor 10. Preferably, the light emitting diode 9 is a gallium arsenide infrared emitting diode and the sensor 10 is an N-P-N silicon photo-transistor. This is a conventional assembly and the diode 9 and photo-transistor 10 are typically mounted in a molded plastic housing.
The assembly 8 is fixed in the carrier 4 and faces the bottom of the supply reel 2 through openings 01 and 02 such that when the supply reel 2 rotates during feed of the tape T, the sensor 10 produces a train of electrical pulses due to the successive passage of the reflective and non-reflective portions 5,6 past the sensor 10. The pulses are fed to one input of a comparator 11 serving as a wave shaper, and a reference voltage is fed to its other input. The output of the comparator 11 is connected to a microprocessor 12 which controls the operation of carrier drive 13 and tape drive 14. When the train of pulses is interrupted due to stoppage of the rotation of the supply reel 2, the microprocessor 12 halts the carrier drive 13 and the tape drive 14.
From the above, it is seen that the train of spaced output pulses from the light sensor 10 are indicative of the continuous rotation of the supply reel 2 which, in turn, indicates a continuous feed of the tape T to the take-up reel 3.
In order to produce the train of pulses, the reflective and non-reflective portions 5 and 6 are in the form of radial stripes or bands which can be directly applied to the bottom of the supply reel 2 or applied to an element which is secured to the supply reel 2 for rotation therewith.
Although the invention has been described in relation to an embodiment which employs light reflection in order to generate the train of electrical pulses, other embodiments are equally applicable in which pulses are produced by periodic change of state of energy which is other than light. For example, magnetic pulses can be produced by a Hall effect sensor or reed switches utilizing magnetic elements.
When using the assembly illustrated in FIGS. 3 and 4, if, when the end of tape T is reached, the supply reel 2 should happen to be stopped at a position in which the sensor 10 is precisely at the transition between a reflective and non-reflective portion 5 and 6, shaking of the carrier 4 could produce an erroneous train of electrical pulses which could maintain the drive of the carrier 4 without feed of the tape T. In order to obviate this possibility, the comparator 11 is provided with high hysteresis by incorporation of a low value resistor R in a feedback circuit. This will insure halt of the carrier drive 13 only when the reflective and non-reflective portions 5 and 6 cease to travel past the sensor 10 in succession.
A further condition of instability can take place at the end of tape feed when the normally adhesively secured end of the tape T can peel off the supply reel 2. As the tape T peels off the supply reel 2, the supply reel 2 rotates and thus pulses are produced from the radial stripes 5 and 6 which give the semblance of normal operation instead of an end of tape condition.
In further accordance with the invention, there is provided a means for positively locking the supply reel 2 at the end of tape feed therefrom. The locking takes place in response to tension in the tape T which exceeds a given value as will become apparent hereafter.
Referring again to FIG. 1 and to the enlarged detail in FIG. 5, therein is seen a ratchet wheel 20 coaxially fixed to the supply reel 2 for rotation therewith. The periphery of the ratchet wheel 20 is formed with triangular ratchet teeth 21 equally spaced thereon. A ratchet lever 22 is supported adjacent to the ratchet wheel 21 by a pivot 23 around which the lever 22 can pivot in opposite directions. A spring 24 is attached to the lever 22 at one end to bias the lever 22 in clockwise direction. The lever 22 carries a pawl tooth 25 which faces the ratchet teeth 21 and is urged into engagement therewith under the force of the spring 24. The tape T passes from the supply reel 2 over a fixed guide roller 26 onto the free end 27 of the lever 22 in its passage to take-up reel 3. In normal operation, the supply reel 2 is prevented from rotating by the engagement of the pawl tooth 25 with a tooth 21 of the ratchet wheel 20. As tape T is pulled by the capstan C, tension in the tape T causes the ratchet lever 22 to rotate counterclockwise about pivot 23. This causes ratchet tooth 25 to disengage from the tooth 21 of the ratchet wheel 20, thus unlocking the ratchet wheel 20. Tension in the tape T now causes the ratchet wheel 20 to rotate clockwise which feeds out tape T from the supply reel 2 which is attached to the ratchet wheel 20. As the tape T is fed out, the lever 22 moves clockwise due to the tension in spring 24. This allows the ratchet tooth 25 to re-engage with a tooth 21 of ratchet wheel 20 thus locking the ratchet wheel 20 again. This process will be repeated until the end of the tape T is reached.
When the supply reel 2 is exhausted of tape T, in order to ensure that there is no motion of the supply reel 2, which would cause electrical pulses, the invention provides for a second pawl tooth 28 on lever 22 to engage ratchet teeth 21 to positively lock the supply reel 2 against rotation.
This is accomplished because as tape T is pulled by capstan C no tape T can be fed out from the supply reel 2 since it is empty and the end of tape T is secured to the supply reel 2 by means of an adhesive. Tension in the tape T increases causing the lever 22 to turn counterclockwise a greater amount than under normal operation. The second ratchet pawl tooth 28 now engages a tooth 21 of the ratchet wheel 20 to positively lock the supply reel 2. In this way, locking of the supply reel 2 takes place at the end of tape T and the sensor 10 can detect halting of the supply reel 2 and halt the carrier and tape drives 13, 14 without any shaking of the carrier 4 causing any false signals.
While the invention has been described in relation to specific embodiments thereof, it will become apparent to those skilled in the art that numerous modifications and variations can be made within the scope and spirit of the invention as defined by the attached claims.
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Apparatus and method for use with a tape cartridge of a printer to determine halt of tape feed from a supply reel to a take-up reel of the cartridge comprising reflective and non-reflective portions on the supply reel rotating therewith and an assembly including a light source and a sensor fixed in position to face the supply reel to cooperate with the reflective and non-reflective portions without mechanical contact therewith for producing a train of successive electrical output pulses as the supply reel rotates. Upon cessation of the output pulses the tape feed is halted. The system also provides a mechanical locking device for effecting positive locking of the supply reel at the end of tape feed.
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FIELD OF THE INVENTION
The present invention relates to systems and methods for quality improvement in an electrically reproduced speech signal. More particularly, the present invention relates to a system and method for babble noise detection.
BACKGROUND OF THE INVENTION
Telephones can be used in many different environments. There is always some background noise around the speaker (far end) as well as around the listener (near end). The type and the level of the background noise can vary from stationary office and car noise to more non-stationary street and cafeteria noise. Many speech processing algorithms try to emphasize the actual speech signal and on the other hand reduce the unwanted masking effect of background noise, in order to improve the perceived audio quality and intelligibility. For these speech enhancement algorithms it is useful to know what kind of noise is present at either end of the transmission link because different noise situations require different performance from the algorithms. It is difficult to classify noises exactly but usually it is enough to classify noise according to its level and degree of mobility.
Telephones are often used in noisy environments and there is always some background noise summed to the speech signal. Many of the speech enhancement algorithms try to improve the quality and intelligibility of the transmitted speech signal by amplifying the actual speech and attenuating the background noise. For detecting the time slots of the signal that really contain speech, algorithms called voice activity detection (VAD) have been developed. These voice activity detection algorithms often interpret speech-like noise, hum of voices, as speech as well, which leads to undesired situations where background noise is amplified. To prevent these situations, a babble noise detection procedure, which determines if the speech detected by VAD is actual speech or just background babble, is needed.
In addition to algorithms using VAD information, some other speech enhancement algorithms, such as artificial bandwidth expansion (ABE), benefit from the background noise classification information. This information about the background noise enables an optimal performance of the algorithm in different noise situations. Babble noise situations often contain other non-stationary noise as well, like for example tinkle of dishes in a cafeteria or rustling of papers. Depending on the case, these sounds can also be included in the concept of babble noise and in that kind of situations it would be desired that the babble noise detector would detect these sounds as well.
In “Noise Suppression with Synthesis Windowing and Pseudo Noise Injection,” A. Sugiyama, T. P. Hua, M. Kato, M. Serizawa, IEEE Proceedings of Acoustics, Speech, and Signal Processing, Volume: 1, 13-17 May 2002, babble noise was detected using zero-crossing information. The noise was considered babble noise if the average number of zero-crossings of a time domain signal exceeded a certain threshold.
Thus, there is a need for an improved technique for detecting babble noise. Further, there is a need to distinguish between speech and background noise. Even further, there is a need to combine results from separate detection algorithms for babble noise detection.
SUMMARY OF THE INVENTION
The present invention is directed to a method, device, system, and computer program product for detecting babble noise. Briefly, one exemplary embodiment relates to a method for detecting babble noise. The method includes receiving a frame of a communication signal including a speech signal; calculating a gradient index as a sum of magnitudes of gradients of speech signals from the received frame at each change of direction; and providing an indication that the frame contains babble noise if the gradient index, energy information, and background noise level exceed pre-determined thresholds.
Another exemplary embodiment relates to a device or module that detects babble noise in speech signals. The device include an interface that communicates with a wireless network and programmed instructions stored in a memory and configured to detect babble noise based on a spectral distribution of noise.
Another exemplary embodiment relates to a device or module that detects babble noise in speech signals. The device includes an interface that sends and receives speech signals and programmed instructions stored in a memory and configured to detect babble noise based on a voice activity detector algorithm.
Yet another exemplary embodiment relates to a system for detecting babble noise. The system includes means for receiving a frame of a communication signal including a speech signal; means for calculating a gradient index as a sum of magnitudes of gradients of speech signals from the received frame at each change of direction; and means for providing an indication that the frame contains babble noise if the gradient index, energy information, and background noise level exceed pre-determined thresholds.
Yet another exemplary embodiment relates to a computer program product that detects babble noise. The computer program product includes computer code to calculate a gradient index as a sum of magnitudes of gradients of speech signals from a received frame at each change of direction; and provide an indication that the frame contains babble noise if the gradient index, energy information, and background noise level exceed pre-determined thresholds or a voice activity detector algorithm and sound level indicate babble noise.
Other principle features and advantages of the invention will become apparent to those skilled in the art upon review of the following drawings, the detailed description, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments will hereafter be described with reference to the accompanying drawings.
FIGS. 1 and 2 are graphs depicting exemplary outputs of babble noise detection algorithms.
FIGS. 3 and 4 are graphs depicting exemplary outputs of babble noise detection algorithms.
FIGS. 5 and 6 are graphs depicting exemplary outputs of babble noise detection algorithms.
FIG. 7 is a flow diagram depicting operations performed in the combination of babble noise detection algorithms in accordance with an exemplary embodiment.
FIG. 8 is a flow diagram depicting operations performed by a spectral distribution based algorithm in accordance with an exemplary embodiment.
FIG. 9 is a flow diagram depicting operations performed by a voice activity detection based algorithm in accordance with an exemplary embodiment.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIGS. 1-2 illustrate graphs 10 and 20 depicting signal output for a VAD algorithm ( FIG. 1 ) and a spectral distribution algorithm ( FIG. 2 ) consisting of two sentences with babble background noise. The dashed line in graph 10 of FIG. 1 is the VAD decision where logical 1 corresponds to detected speech. The dotted line in graph 10 of FIG. 1 is the babble decision made by the VAD based babble noise detection algorithm. The dotted line in graph 20 of FIG. 2 is the babble decision made by the feature-based algorithm.
FIGS. 3-4 illustrate graphs 30 and 40 depicting signal output for a VAD algorithm ( FIG. 3 ) and a spectral distribution algorithm ( FIG. 4 ) consisting of two sentences. The graph 30 depicts the output for a VAD based detection algorithm. The graph 30 shows that the second sentence is incorrectly almost completely detected as babble noise because the level of the second sentence is lower than the first one. In contrast, the graph 40 depicts the output for babble noise detection based on spectral distribution of noise. The graph 40 shows no babble noise is detected.
FIGS. 5-6 illustrate graphs 50 and 60 depicting signal output for a VAD algorithm ( FIG. 5 ) and a spectral distribution algorithm ( FIG. 6 ) consisting of a sentence followed by quiet babble noise. The graph 50 depicts the output for a VAD based detection algorithm. The graph 50 shows that the babble noise is detected. In contrast, the graph 60 depicts the output for babble noise detection based on spectral distribution of noise. The graph 60 shows that the algorithm fails to detect babble noise because of its low-pass characteristics.
Accordingly, babble noise can be better detected when a VAD based algorithm and a spectral distribution algorithm are combined or used separately in the situations which fit best to the particular algorithm chosen. In an exemplary embodiment, both of the algorithms process the input signal in 10 ms frames.
In general, voice activity detection (VAD) algorithms often interpret speech-like noise, hum of voices as speech. The VAD based babble noise detection algorithm corrects those incorrect decisions made by VAD by monitoring the level of detected speech, since the level of hum is usually lower than the level of the actual speech. If the input signal level suddenly drops by more than a predetermined amount (such as 5 dB, 25 db<50 dB, ect.) from its long-term estimate, the assumption of the babble noise situation is made. The VAD based babble noise detection algorithm detects only babble noise that really is hum of voices.
The spectral distribution algorithm is based on a feature vector and it follows the longer-term background noise conditions. It monitors only the characteristics of noise without taking into account the decision of VAD, e.g. the information if the frame contains speech or not. The babble noise detection is based on features that reflect the spectral distribution of frequency components and, thus, make a difference between low frequency noise and babble noise that has more high frequency components. The spectral distribution based algorithm detects hum of voices as well as other non-stationary noise as babble noise.
Since these algorithms define and detect babble noise differently, in some cases it is advantageous to combine the information they can provide. How this is done depends on the definition of babble noise and the needed accuracy of babble noise detection. For example, the spectral distribution babble noise decision can be used to double-check the negative or positive babble noise decision made by the VAD based detection algorithm.
Babble noise detection based on spectral distribution of noise is based on three features: gradient index based feature, energy information based feature and background noise level estimate. The energy information, E i , is defined as:
E i = E [ s nb ′′ ( n ) ] E [ s nb ( n ) ] ,
where s(n) is the time domain signal, E[s′ nb ] is the energy of the second derivative of the signal and E[s nb ] is the energy of the signal. For babble noise detection, the essential information is not the exact value of E i , but how often the value of it is considerably high. Accordingly, the actual feature used in babble noise detection is not E i but how often it exceeds a certain threshold. In addition, because the longer-term trend is of interest, the information whether the value of E i is large or not is filtered. This is implemented so, that if the value of energy information is greater than a threshold value, then the input to the IIR filter is one, otherwise it is zero. The IIR filter is of form:
H ( z ) = 1 - a 1 - az - 1 ,
where a is the attack or release constant depending on the direction of change of the energy information.
The energy information has high values also when the current speech sound has high-pass characteristics, such as for example /s/. In order to exclude these cases from the IIR filter input, the IIR-filtered energy information feature is updated only when the frame is not considered as a possible sibilant (i.e., the gradient index is smaller than a predefined threshold).
Gradient index is another feature used in babble noise detection. In babble noise detection, the gradient index is IIR filtered with the same kind of filter as was used for energy information feature. The background noise level estimation can be based on, for example, a method called minimum statistics.
If all three features, (IIR-filtered energy information, IIR-filtered gradient index and background noise level estimate) exceed certain thresholds, then the frame is considered to contain babble noise. By requiring all there features to exceed certain thresholds, this embodiment of the invention can minimize the number of false positives (i.e. the number of times a frame is incorrectly considered to contain babble noise). In at least one embodiment, in order to make the babble noise detection algorithm more robust, fifteen consecutive stationary frames are used to make the final decision that the algorithm operates in stationary noise mode. The transition from stationary noise mode to babble noise mode on the other hand requires only one frame.
Voice activity detector (VAD) algorithms are used to interpret time instants when the signal contains speech instead of mere background noise. These algorithms often interpret speech-like noise also as speech. However, the level of this kind of hum of voices is usually lower than the level of the actual speech. Using this assumption it is possible to monitor the level of the input signal, interpreted as speech by the VAD, and compare it to its long-term estimate. If the input signal level suddenly drops by more than, for example, 15 dB from its long-term estimate, an assumption of the babble noise situation is made. During babble noise, the long-term speech estimate is kept intact.
If the level of the actual speech signal drops suddenly, the babble noise detection algorithm triggers falsely. This result would prevent the updating of the long-term speech level estimate. For these kind of situations, the algorithm has a safety control, which is performed after 20-30 seconds. This safety control forces the update of the long-term estimate, if short-term estimate has not reached the long-term estimate for a given number of samples. The time period of 20-30 seconds is justified because it is somewhat the typical maximum time a person keeps completely silent in a telephone conversation, and thus the long-term estimate should be updated more frequently than that.
These two separate babble noise detection algorithms both have their advantages and disadvantages. Fortunately, these algorithms usually fail in different situations. How the combining of the babble noise detection decisions of the algorithms should be done, depends on the situation since the definition of babble noise is not exact and speech processing algorithms need the babble noise detection information for different reasons.
FIG. 7 illustrates a flow diagram depicting exemplary operations performed in the combination of the VAD and spectral distribution algorithms to detect babble noise. Additional, fewer, or different operations may be performed, depending on the embodiment. In a block 72 , babble noise is detected if either of the algorithms gives a logical 1 (i.e., positive babble noise decision). Such a combination could be used in cases were it is vital to detect babble noise and the concept of babble noise is wide.
If the VAD based algorithm detects babble after a long non-babble period in block 74 , the decision of the spectral distribution algorithm is checked in block 76 before making the final babble decision. If the spectral distribution algorithm gives a logical 1 as well, babble is detected, if not, there is a wait period in block 78 of a control safety time (e.g., 20-30 seconds). The long-term estimate is then updated in block 79 and the babble decision is made after that. This combination could be used, for example, if faulty babble noise detections are a problem. Occasions where quiet speech is faulty detected as babble noise would be prevented.
FIG. 8 illustrates a flow diagram depicting exemplary operations performed in a spectral distribution based algorithm used to detect babble noise. Additional, fewer, or different operations may be performed, depending on the embodiment. In block 80 , an input signal is received and in block 82 , a gradient index is calculated, for example as described herein. In block 84 , the gradient index is compared to a predetermined gradient index threshold. If the gradient index does not exceed the threshold, the algorithm returns to block 80 and additional input signal is received. If the gradient index does exceed the threshold, the input signal energy is compared to a predetermined input signal energy threshold in block 86 . If the input signal energy does not exceed the predetermined threshold, the algorithm returns to block 80 and additional input signal is received. If the input signal energy does exceed the threshold, the background noise level is compared to a predetermined background noise level threshold in block 88 . If the background noise level does not exceed the threshold, the algorithm returns to block 80 and additional input signal is received. If the background noise level does exceed the threshold, an indication that the input signal includes babble noise is made in block 89 .
FIG. 9 illustrates a flow diagram depicting exemplary operations performed in a VAD based algorithm used to detect babble noise. Additional, fewer, or different operations may be performed, depending on the embodiment. In block 90 , an input signal is received and in block 92 the input signal is monitored by a VAD based algorithm. In block 94 , the VAD based algorithm compares the input signal to a predetermined input signal threshold and if the input signal level suddenly falls below the predetermined threshold, an indication that the input signal includes babble noise is made in block 96 . If the input signal level does not fall below the predetermined threshold, the algorithm returns to block 90 and additional input signal is received.
Advantageously, depending on the purpose of usage, only one of the algorithms or both of them can be used to detect babble noise. Further, combining the separate detection algorithms helps overcome their problems by using their strengths.
This detailed description outlines exemplary embodiments of a method, device, and system for babble noise detection. In the foregoing description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It is evident, however, to one skilled in the art that the exemplary embodiments may be practiced without these specific details. In other instances, structures and devices are shown in block diagram form in order to facilitate description of the exemplary embodiments.
While the exemplary embodiments illustrated in the Figures and described above are presently preferred, it should be understood that these embodiments are offered by way of example only. Other embodiments may include, for example, different techniques for performing the same operations. The invention is not limited to a particular embodiment, but extends to various modifications, combinations, and permutations that nevertheless fall within the scope and spirit of the appended claims.
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A method, device, system, and computer program product calculate a gradient index as a sum of magnitudes of gradients of speech signals from a received frame at each change of direction; and provide an indication that the frame contains babble noise if the gradient index, energy information, and background noise level exceed pre-determined thresholds or a voice activity detector algorithm and sound level indicate babble noise.
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BACKGROUND OF THE INVENTION
The present invention relates to a tool for measuring the pressure created in an oil well by the underground formation where the well is drilled, with the well being delimited by casing having production string installed therein, and with the string including a section that constitutes a sliding sleeve circulating valve or sliding side door (SSD), said valve being capable, on command, of putting the space inside the string into communication with the annular space lying between the string and the casing. This is done by bringing orifices through the wall of said section and through the sliding sleeve into register.
Pressure measurements in oil wells provide important information on the characteristics of the oil-bearing formations through which they are drilled. In wells where production is obtained by means of electric pumping, the pressure drop due to a sudden momentary increase in the flow rate at the surface can be used to calculate the production index, i.e. the production capacity of the well as a function of pressure drop. Given this index, which depends on the permeability and on the size of the reservoir constituted by the underground formation, it is possible to adjust the production flow rate to its optimum value.
It is also possible to set up an increase in pressure in a well by suddenly stopping pumping. The rate of this increase and its form as a function of time characterize the manner in which the reservoir responds and make it possible to evaluate its size and its porosity, to discover whether it is fractured, etc., thereby giving rise to a better description of the reservoir and to a more accurate understanding of its future capabilities and of the advisability of drilling other wells in its vicinity.
In a third application relating to wells which are exploited by electrical pumping, it is possible to evaluate the efficiency of the pump being used and to detect possible damage which may be shown up by abnormal variations in efficiency, by measuring the pressure created by the underground formation at a given depth, i.e. the pressure reigning in the above-mentioned annular space, while simultaneously measuring the pressure in the string at the same depth, which pressure depends on pumping characteristics.
The pressure created by the underground formation must be measured in the annular space lying between the casing and the production string. The height of the column of oil in said annular space is directly related to this pressure, and proposals have been made to measure this height from the go and return time of an acoustic wave emitted from the surface of the ground and reflected from the air-oil interface of the column. However, this procedure is not usable when the annular space is closed at the top by sealing means known as a packer.
Attempts have also been made to measure the pressure at the bottom of a well which is being exploited by electrical pumping by associating a pressure sensor with the pump. The results obtained in this way have been unsatisfactory since the pressure data provided by such a sensor (which must remain at the bottom of the well for as long as the pump remains at the bottom) falls off in quality over the years. In addition, the electrical signals delivered by the sensor are mixed with noise. As a result measuring accuracy is very mediocre.
Another proposal consists in placing a pressure gauge on the outside surface of the production string. However, the presence of said packer (i.e. sealing means) in the annular space interferes with passing an electrical cable connected to the pressure gauge since that cable must reach the surface by running up the annular space.
SUMMARY OF THE INVENTION
In order to solve the problem of measuring pressure in oil wells, the present invention provides a tool designed to be lowered inside the production string and locked at the level of the section which includes the circulating valve SSD with the valve in its open state. This tool includes means for putting the orifices of said valve (when brought into register) into sealed connection with a pressure sensor, - said connection being sealed against pressure reigning in the production string, - such that said sensor has the pressure reigning in the above-mentioned annular space level with said section applied thereto via said orifices and said sealed connection means.
Thus, by virtue of such a tool which takes advantage of the circulating valve already present in the production string, all of the equipment required for measuring pressure and including said tool, namely the pressure sensor and the associated members which enable the tool to be put into place, may be contained inside the production string so that the presence of a packer (sealing means) no longer constitutes an obstacle since nothing needs to be lowered or installed inside the annular space. Further, the tool can be removed at the end of a pressure measurement cycle by being raised up the production string in the same way as the tools which are conventionally used in oil drilling applications.
In an advantageous embodiment of the invention, the tool comprises two coaxial elements capable of sliding telescopically, namely a first tubular element whose outside diameter is slightly less than the inside diameter of the production string, and a second element capable of sliding over a limited stroke in an inside bearing of the first element and including a duct for providing sealed connection between the pressure sensor and said orifices. This disposition makes it possible to disengage the top of the first element by retracting the second element inside the first, thereby making it easier to grasp the first element by a lowering or raising tool, optionally via an anchoring mandrel fixed to the first element and maneuverable by means of a lowering or fishing tool, and which is lockable in the section constituting the circulating valve of the production string.
It is also advantageous for the second element to be able to take up, relative to the first element, firstly a low position determined by an end-of-stroke abutment in which the second element is entirely contained within the first element, and secondly a high position, likewise determined by an end-of-stroke abutment, in which said duct is put into communication with the orifices of the circulating valve. According to another characteristic of the invention, this duct opens out onto the outside surface of the second element at a position such that when said element is in its high position the opening of the duct is situated in the middle region of the internal bearing surface of the first element and is thus in communication with at least one channel passing through the wall of the first element and itself in communication, via an annular space lying between the outside surface of the first element and the inside surface of the sliding sleeve, with the orifices through the sleeve and through the wall of the section constituting the circulating valve. Further, in order to make it possible for the second element to take up any orientation about the longitudinal axis of the tool it is advantageous for the above duct to open out into an annular groove formed in the inside bearing of the first element and communicating with the or each channel passing through the wall thereof.
In an advantageous embodiment, the pressure sensor is carried by the tool and is preferably mounted on the tool in removable manner so that the tool and the pressure sensor may be maneuvered independently. To this end, according to another characteristic of the invention, the top of the second element of the tool includes a tubular junction end fitting with said connection duct ending in said end fitting and serving to connect the duct in sealed manner to the pressure sensor. Further, the pressure sensor is preferably coupled to the end fitting via separable connection including fingers which cooperate with a system of J-grooves and enabling the pressure sensor to be coupled with and then decoupled from the end fitting under control from the surface of the ground by means of a suspension cable.
In order to allow oil to pass through the tool when in place in the production string, it is advantageous for the second element of the tool to include a lower tubular portion having at least one orifice at the top thereof. Further, pressures within the production string may be equalized when the tool is removed by providing for the abutment defining the low position of the second element to be constituted by a ring which is fixed in non-final manner in the first element and which closes at least one orifice passing through the wall of the first element, with said ring being expelled at the end of tool use by means of a fishing tool designed to force the second element to move down relative to the first, thereby uncovering said orifice which then puts the spaces situated inside and outside the first element into communication.
Other characteristics and advantages of the invention appear more clearly from the following description of a non-limiting embodiment of the invention given with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic longitudinal section through an oil well fitted with production string including a section constituting a circulating valve;
FIGS. 2, 3, and 4 are diagrams in longitudinal section and to a larger scale showing a tool in accordance with the invention respectively while being lowered down the production string, after being put into place in the section constituting a circulating valve, and while in service for performing pressure measurements;
FIGS. 5A, 5B, and 5C which are interconnected along lines AB and CD shown a practical embodiment of an entire tool in longitudinal section;
FIG. 6 shows the tool of FIGS. 5A, 5B, and 5C ready for raising after a cycle of pressure measurements have been completed; and
FIG. 7 is a diagram in the form of a plane development of a portion of the peripheral surface of a J-groove drum included in the tool in order to connect and disconnect the pressure sensor.
DETAILED DESCRIPTION
FIG. 1 shows an oil well delimited by casing 10 and having production string 11 installed therein. The casing 10 includes perforations 12 in an oil-bearing formation 13 where the well is drilled, and via which oil penetrates into the well. By virtue of its pressure, the oil rises to a level N (situated beneath the ground surface 18) inside the annular space 15 between the casing 10 and the production string 11. A submerged pump 16 (fitted with a non-return valve) is mounted at the bottom of the production string and serves to deliver oil up said string to the surface where it is made available on a Christmas tree 17. Not far from the ground surface 18, the annular space 15 is closed by circular sealing means known as a packer 19, and a safety valve 20 may be disposed at that level. A short way above the pump 16, the production string 11 includes a circulating valve section SSD comprising a sliding sleeve 21 which can be operated to provide a communication path between the inside of the production string 11 and the annular space 15 (mainly for the purpose of killing the well by filling it with mud), by putting orifices 22 and 23 provided respectively through the wall of the section SSD extending the wall of the production string 11 and through the sliding sleeve 21 into communication with each other.
It is this communication path which is used by a tool in accordance with the invention as described below for the purpose of measuring the oil pressure in the annular space 15 not far from the formation 13.
As shown in diagrammatic and simplified form in FIG. 4, a tool in accordance with the invention essentially comprises two elements 1 and 2 which are generally tubular in shape and which are disposed coaxially about the axis A of the production string 11. The larger diameter element 1 is capable of sliding inside the production string 11 and the smaller diameter element 2 is capable of sliding inside the element 1. More precisely, the outside surface of the element 1 which is in the form of a circular cylinder has a diameter which is selected so as to enable it to be a sliding fit inside two internal sealing bearing surfaces 24 and 25 provided on the section SSD of the production string on either side of the moving sleeve 21, said bearing surfaces also limiting the sliding stroke thereof. The top bearing surface 24 includes an annular groove 26 (see FIG. 2) for receiving the locking keys 27 of an anchoring mandrel 28 which is fixed to the top end of the element 1. Near the bottom end of the element 1 there is a sealing ring 38 which co-operates with the bottom sealing bearing surface 24 of the section SSD when the element 21 is fixed in the section SSD by means of the anchoring mandrel 28 locking via its keys 27 (FIG. 4). As a result, the oil delivered by the pump 16 into the production string 11 can only flow along the inside volume of the element 1.
The sliding sleeve 21 is received in the annular space 29 delimited by the inside surface of the section SSD, its bearing surfaces 24 and 25, and the outside surface of the element 1. The outside diameter of the sleeve 21 corresponds to the inside diameter of the section SSD between said bearing surfaces. However, the inside diameter of the sleeve is greater than the outside diameter of the element 1 so that an annular space 30 appears between the element 1 and the sleeve 21. The orifices 22 through the section SSD are naturally situated between the bearing surfaces 24 and 25, whereas the lengthwise positions (relative to the sleeve) of the orifices 23 through the sleeve 21, and the length of the sleeve itself, are selected in such a manner that depending on the extreme longitudinal position occupied by the sleeve within the section SSD, these orifices either come face-to-face into register with the orifices 22 through the section SSD, thereby putting the space 30 into communication with the space 15 surrounding the section SSD, or else the orifices 22 are closed by the cylindrical wall 21a of the sleeve 21. Each end of the sleeve includes in inwardly directed annular rim 21b or 21c to provide engagement with an actuator member for sliding the sleeve upwardly or downwardly.
The element 2 is essentially constituted by a hollow cylindrical portion 2a together with an end fitting 2b which extends beyond the top end of the hollow cylindrical portion for the purpose of connection to a pressure sensor 31. The portion 2a whose outside diameter is slightly less than the inside diameter of the element 1 is capable of sliding longitudinally therein and of being guided by an internal bearing surface 1a which projects inwardly from the inside surface of the element 1. The upwards excursion of the element 2 is limited by an outwardly directed collar 2c on the portion 2a near the bottom end thereof coming into abutment against said inside bearing surface 1a of the part 1, and its downward excursion is limited by a ring 32 fixed inside the element 1 and against which the bottom end of the element 2 comes into abutment (FIG. 3). The top end of the portion 2a has orifices 33 passing therethrough to enable oil to flow through the tool, via the inside spaces of the element 1 and said portion 2a of the element 2.
The inside bearing surface 1a of the element 1 has an annular groove 1b formed therein which is open towards the inside of the element and which is connected to the space surrounding it via channels 1c passing radially through its cylindrical wall. The element 2 includes a duct 35 which is connected at one end to a channel 2d running axially through its end fitting 2b, and opens out at its other end through the cylindrical wall of its portion 2a into the above-mentioned annular groove 1b when the element 2 is in its high abutment position inside the part 1, as shown in FIG. 4. Under these conditions, the annular space 30 which communicates via the orifices 23 and 22 with a space 15 surrounding the section SSD is in connection with the axial channel 2d of the end fitting 2b, via the channels 1c, the groove 1b, and the duct 35, regardless of the orientation of the element 2 about the axis A. As to the end fitting 2c, it may be put into connection with the pressure sensor 31 by means of a junction sleeve 3 connected in sealed manner at its top end to said sensor and via an inside bearing surface 3a to the end fitting 2b.
In order to allow the pressure sensor 31 to be put into place and to be removed, the sleeve 3 may be fastened to the end fitting 2b or it may be removed therefrom at will simply by imparting axial displacement thereto by means of a suspension cable 36 to which it is attached, in a manner described below.
When pressure measurements are to be made in the well, the tool 1, 2 is lowered down the production string 11 to be put into position level with the circulating valve forming section SSD. The sliding sleeve 21 of this section which is normally in the closed position will have previously been put into its open position such that the orifices 22 and 23 are face-to-face. While the tool is being lowered (FIG. 2), its element 2 is in its low position inside the part 1 resting against the ring 32 fixed to the bottom thereof, thereby disengaging the anchoring mandrel 28 and enabling the mandrel to be coupled to a lowering tool 37 (see FIG. 3) attached to the suspension cable 36. Finally, the keys 27 of the anchoring mandrel 28 are engaged in the groove 26 of the top bearing surface 25 of the section SSD, thereby fixing the tool therein with the channels 1c of the part 1 opening outwardly into the annular space 30 lying between the rims 21b and 21c of the sleeve 21, and with the sealing ring 38 of the part 1 being face-to-face with the bottom bearing surface 24 of the section SSD to provide sealed contact at said location beneath the sleeve 21. Above the sleeve, sealing is likewise ensured by a sealing ring 39 belonging to the anchoring mandrel 28 and co-operating with the top bearing surface 25.
While the tool 1, 2 is being lowered, pressure is equalized in the production string 11 between the spaces situated above the tool and below the tool via the channels 1c.
After the tool 1, 2 has been put into place, the lowering tool 37 is detached and raised to the surface by means of the cable 36. Then, the same cable is used to lower the junction sleeve 3 carrying the pressure sensor 31. This sleeve fits in sealed manner via its inside bearing surface 3a fitted with a sealing ring 40 onto the end fitting 2b of the element 2 of the tool. Thus, the sensor 31 is put into communication with the duct 35 via the channel 2c through the end fitting 2b (FIG. 4). At the same time, a pair of fingers 3b with which the sleeve 3 is provided come into engagement with a system of grooves 41 which appear on the outside surface of a drum-shaped portion of the end fitting 2b and which constitute (see FIG. 7) a succession of J-shaped grooves which are so designed that by lowering and raising the sleeve 3 slightly, its fingers 3b move down vertical passages 41.1 and are then received in notches 41.2, with the parts 2 and 3 then being coupled together. Next time the sleeve 3 is lowered and then raised, the fingers 3b move down along sloping passages 41.3 and then rise up passages 41.4 so as to escape from the system of grooves 41, with the part 2 and 3 then being disconnected (and so on).
In the FIG. 4 configuration, the tool 1, 2 puts the associated pressure sensor 31 which is likewise immersed in the oil contained in the production string 11 into communication with the annular space 15 surrounding the production string so as to enable measurements to be made of the pressure of the oil contained therein. In parallel, throughout the time that the tool 1, 2 is in service in the production string 11, oil may rise under the delivery effect of the pump 12 along said string by passing through the tool with minimum interference, via a non-return valve constituted by a ball 42 and a conjugate circular seat 43 provided at the bottom of the element 1, followed by the inside space thereof, the inside space of the portion 2a of the element 2, and the orifices 33 thereof (FIG. 4). Said non-return valve is in addition to the nonreturn valve which is fitted to the pump 16 and takes over therefrom in the event of a leak.
The efficiency of the pump 16 may be determined by associating the pressure sensor 31 with a second pressure sensor (not shown) which measures the pressure inside the production string.
FIGS. 5A, 5B, and 5C show a concrete example of a tool embodying the invention in its FIG. 4 configuration. The various component parts of the well and the tool outlined in FIG. 4 can be recognized therein, namely:
the production string 11 which is coaxial with the casing 10, and including a circulating valve section SSD fitted with the sleeve 21 capable of sliding between the inside bearing surfaces 24 and 25, with the respective orifices 22 and 23 being shown, in this case, face-to-face;
element 1 of the tool (constituted by an assembly of several parts) which is screwed to the anchoring mandrel 28 and which is held fixed in the section SSD by locking keys 27 on the mandrel, with sealing on either side of the sliding sleeve 21 being provided by inside bearing surfaces 24 and 25 cooperating with sealing rings 38, 39;
element 2 of the tool (constituted by an assembly of several parts) sliding in the inside bearing 1a of element 1 by means of its tubular portion 2a, the top of which includes the through orifices 33 and terminates by end fitting 2b;
the duct 35 leaving end fitting 2b and going down inside the part 2a of element 2 and then passing through the wall thereof to open out into the annular groove 1b formed in the bearing surface 1a of element 1 between two groups of sealing rings 44a and 44b provided on this bearing surface, with the groove 1b communicating via channels 1c with the annular space 30 lying between the element 1 and the sliding sleeve 21;
the junction sleeve 3 coupled in sealed manner to the end of end fitting 2b via its internal bearing surface 3a which is provided with two sealing rings 40, and engaging the end fitting 2b via a pair of fingers 3b engaged with the J-grooves 41 of said end fitting, with the pressure sensor 31 being coupled in sealed manner to said junction sleeve;
the ring 32 fixed inside the element 1 and defining the bottom position of the sliding element 2, with its top position being defined by the valve in abutment of the flange 2c against the bearing surface 1a of element 1; and
the non-return valve 42, 43 disposed at the bottom end of the element 1, beneath the ring 32.
It can be deduced from the set of FIGS. 5A, 5B, and 5C that unlike the diagram of FIG. 3, the element 2 is completely contained inside the element 1 when in its bottom position pressed against the ring 32, with its end fitting 2a terminating beneath the bearing surface 1a of the element 1 and beneath the orifices 1c. Thus, in this situation, the anchoring mandrel 28 is completely free to enable the lowering tool 37 to be fastened thereto.
In addition, FIG. 5C shows the presence of an orifice 49 through the wall of the element 1 of the tool and suitable for putting the spaces situated on either side of said wall into communication. However, in the normal situation shown, this orifice is closed and rendered inoperative by the ring 32 which co-operates with an internal bearing 1d of the element 1 in sealed contact by virtue of a pair of sealing rings 51, with the orifice 49 being located therebetween. Thus, this orifice opens out on the inside of the element 1 into a narrow closed annular chamber which is delimited by the bearing surface 1d, the periphery of the ring 32, and the pair of sealing rings 51. As explained below, the orifice 49 may be put into operation by expelling the ring 32 since this is fixed in the bearing surface 1d by a pair of shearable pins 52. Naturally, instead of a single orifice 49, there could be a plurality of orifices 49 likewise located between the two sealing rings 51 while the ring 32 is in position in the bearing surface 1d of the element 1.
FIG. 6 shows the final stage once pressure measurements have been completed and before the tool is raised. By acting on the cable 36, the end fitting 2b of the junction sleeve 3 is uncoupled and raised to the surface together with the pressure sensor 31. A fishing tool 45 is then lowered and this fastens onto the anchoring mandrel 28. At the end of its downwards stroke, the fishing tool 45 thrusts the element 2 downwardly by means of an axial arm 46 belonging to the fishing tool, thereby releasing the ring 32 by shearing the pins 51 which used to fix it to the element 1, and causing the ring to move down as far as a transverse abutment rod 48. When this happens the orifice(s) 49 put the spaces inside and outside the element 1 into communication, thereby equalizing the pressures while the tool 1, 2 is raised, with the non-return valve 42, 43 being closed. During subsequent raising of the tool 1, 2, equalization of said pressures may also take place via the channels 1c of the element 1.
When a safety valve 20 is provided in the top portion of the production string 11, the valve must be removed in order to allow the tool 1, 2 to be lowered, after which it can be put back into place.
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The invention relates to a tool for measuring pressure in the annular space lying between casing and the production string of an oil well. The tool comprises two sliding elements, with the first element being temporarily locked in a section of the string constituting a circulating valve and with the second element carrying a pressure sensor which receives the pressure reigning in the annular space via a duct and orifices of the circulating valve after they have been brought into register.
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[0001] The present invention generally refers to probiotic and therapeutic formulations and, more in particular, it relates to compositions comprising lactic acid bacteria or bifidobacteria with low molecular weight non-proteinaceous iron chelators, useful for the treatment of infections of the human body cavities.
BACKGROUND OF THE INVENTION
[0002] Infections of human body cavities such as, for example, the female genital tract and the intestine, are widely spread pathological conditions known to affect, even recurrently, the majority of population.
[0003] Antibiotics are often used to combat these pathological conditions despite the fact that their prolonged use may contribute to the emergence of antibiotic-resistant pathogenic bacterial strains.
[0004] As this emergence may pose a serious risk to human beings, it is highly desirable to develop products for the therapy of infections of the body cavities that are not based on antibiotics and, hence, do not lead to the development of antibiotic resistance.
[0005] Body cavities including the vaginal tract, the male urethra, the intestine and the buccal cavity, are known to be naturally colonized by probiotic bacteria, for instance lactic acid bacteria and bifidobacteria. The normal flora of both the vagina and the gastrointestinal tract consists of a wide variety of genera and species, either anaerobic or aerobic, dominated by the facultative microaerophilic anaerobic genus Lactobacillus (Ref. 1, 2 and 8). These species are known to defend the mucosal surfaces from colonization by pathogenic microorganisms such as, e.g., toxigenic bacteria and yeasts.
[0006] In this respect, the so-called probiotic approach to health maintenance and therapy consists, essentially, in delivering the probiotic bacteria to the body cavities, which in healthy individuals are inhabited by commensal microorganisms, in order to fostering or reconstituting the natural environment.
[0007] To this extent, as commensal microorganisms are known to compete with pathogenic ones, they can have disease preventive properties or even curative properties.
[0008] Many commensal microorganisms have been studied so far and special attention has been given to various lactobacillus or bifidobacterium species as well as to Enterococcus faecium SF68 and the yeast Saccharomyces boulardii.
[0009] Among them, particularly promising appear to be lactobacillus and bifidobacterium species.
[0010] Lactic acid bacteria and bifidobacteria are natural hosts of the intestines and the vagina, where they protect the tissue from pathogenic organisms that, by adhering to the mucosa and tissues, may invade body cavities.
[0011] It has been shown that Lactobacillus paracasei strains CNCM I-1390 and CNCM I-1391 and Lactobacillus acidophilus strain CNCM I-1447, isolated from healthy babies, bind in large numbers to both buccal and intestinal epithelial cells (Ref. 29), thus demonstrating that they naturally adhere to the same mucosal cells as it may occur for pathogenic microorganisms.
[0012] As such, a competition for binding sites between pathogenic microbes and healthy lactic acid bacteria, within body cavities, has been demonstrated (Ref. 30 and Ref. 37).
[0013] Some lactic acid bacteria, in addition, proved to inhibit growth of pathogens. Among them are, for example, Lactobacillus paracasei strains CNCM I-1390 and CNCM I-1391 and Lactobacillus acidophilus strain CNCM I-1447 that are able to inhibit, in vitro, the growth of enterotoxigenic E. coli ATCC 35401 or Salmonella enteritidis IMM 2.
[0014] Moreover, a mixture of these lactobacillus strains resulted particularly effective in the inhibition, although weak, even of the Vibrio cholerae E1 Tor (Ref. 31).
[0015] Because of all the above, pharmaceutical products containing lactic acid bacteria or bifidobacteria, for the prevention or treatment of pathological infections, are known in the art and have been already described.
[0016] Among them are, just as an example, vaginal capsules comprising a strain of Lactobacillus gasseri; lactobacillus vaginal suppositories to prevent recurrence of urinary tract infections after antibiotic therapy (Ref. 3); vaginal medicaments based preferably on Lactobacillus crispatus CTV-05 effective against a variety of pathogens (Ref. 4).
[0017] Various other products also intended for oral administration and containing live lactic acid bacteria or bifidobacteria are also known in the art and recommended, for instance, in the treatment of diarrhea. These products may come either as pharmaceutical formulations or in the form of fermented milk products.
[0018] However, although disease prevention and/or therapy with commensal lactic acid bacteria and bifidobacteria have shown some efficacy (Ref. 5 to 12), the evidence was never sufficiently convincing to lead to a widely spread standard form of treatment. Presumably, this is because they are not yet as effective as one would expect, at least on theoretical basis.
[0019] It is known that iron is an essential growth factor, basically for every cell and microorganism. The unsatisfactory therapeutic results obtained with previous products comprising commensal microorganisms have been thus associated with too elevated concentrations of free iron (III) ions, which promote the growth of pathogens while disfavoring a number of lactic acid bacteria.
[0020] Lactoferrin (see The Merck Index, XIII Ed., 2001, No. 9647), a glycoprotein endogenously produced by neutrophils and also known to be a major component of secreted fluids, including saliva, gastric juices and bile, is a very important factor of the human milk bacteriostatic system.
[0021] Because of its iron chelating properties, the inclusion of lactoferrin, either per se or in combination with other organic components, is widely known in the art, particularly regarding the dietary supplements (Ref. 14).
[0022] Lactoferrin capsules may thus contain, for example, said protein with a degree of purity up to 95% and in amounts up to 480 mg.
[0023] However, in preliminary therapeutic trials with very small numbers of patients, only few indications of any antibacterial (Ref. 15) and antiviral efficacy (Ref. 16) of the lactoferrin based products were obtained, and the results were insufficient to fostering further studies on this approach.
[0024] Some combinations of lactic acid bacteria with lactoferrin are also commercially available (e.g., Colostrum with Lactoferrin Chewable Tablets, Peak Nutrition Inc., Syracuse N.Y.). In this product, however, the quantity of live bacteria (≦3.4×10 6 CFU) is orders of magnitude below the limit required for effective intestinal colonization.
[0025] Moreover, to the extent of our knowledge, there are no animal or clinical studies demonstrating the efficacy of the combination of lactic acid bacteria with lactoferrin over the bacteria alone.
[0026] Lactoferrin has also been suggested to have multiple biological roles including facilitating iron absorption, modulating the immune response, regulating embryonic development and influencing cell proliferation. In addition, it has also been demonstrated the role of the mentioned protein in regulating the release of tumor necrosis factor alpha and interleukin 6 (Ref. 17).
[0027] Oral lactoferrin may thus produce many different effects than simple sequestration of iron ions.
[0028] Remarkably, it has been demonstrated that certain pathogens can even utilize lactoferrin as an iron source (Ref. 18), thereby counteracting the intended purpose of withholding iron ions from bacteria. For these reasons, the possible therapeutic use of lactoferrin remains a very questionable choice if solely chelation or sequestration of iron ions is intended to be associated with probiotic bacteria.
[0029] A low molecular weight natural chelator for iron, namely deferoxamine (see The Merck Index, XIII Ed., 2001, No. 2879), has been used to study the mechanisms of bacterial iron transport and its participation in the competition of commensal lactic acid bacteria with the pathogen Neisseria gonorrhoeae, in the mouse genital tract (Ref. 19). It was observed that “the degree of lactobacillus grown on base agar with and without deferoxamine was similar” and it was therefore concluded that “commensal lactobacilli may increase the availability of iron to N. gonorrhoeae during infection of females, although the exact mechanism by which this occurs is not known”.
[0030] Furthermore, it is also known the ability of certain Bifidobacteria to produce a siderophore, particularly where said bifidocateria are grown on agar in the presence of an iron chelator moiety (Ref. 38).
[0031] Nevertheless, no suggestions regarding the possible use of a chelator in the formulation of therapeutic or probiotic products were ever made. In any case, it is known that certain bacteria actually possess a deferoxamine receptor (Ref. 20). Accordingly, being a natural siderophore, i.e., an iron uptake mediator, from Streptomyces pylosus, it can also act as siderophore for certain pathogenic bacteria, e.g., Yersinia enterocolitica and Yersinia pseudotuberculosis (Ref. 21), thus exerting the undesired feature of iron donor.
[0032] Low molecular weight non-proteinaceous iron chelators have been shown to possess antimicrobial activity on species that require iron.
[0033] In particular, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), trans-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid (CDTA) and triethylene-tetraaminehexaacetic acid (TTHA) have been shown to inhibit the growth of Staphylococcus epidermidis (Ref. 22). A number of chelators including R,S-ethylenediaminedisuccinic acid (R,S-EDDS), have been shown to inhibit growth of Corynebacterium xerosis ATCC 7711 (Ref. 23).
[0034] Low molecular weight non-proteinaceous iron chelators have also been proposed as additives in buccal disinfectants (Ref. 24), as additives in topical deodorant formulations (Ref. 22, 23 and 25), as components of bactericidal compositions for intestinal use (Ref. 26) and, apparently, for topical use (Ref. 27). A catamenial tampon carrying a chelator was also conceived (Ref. 25).
[0035] Chelators with selectivity for first transition series elements, which include iron, intended for use in several biomedical applications, including bacterial and fungal replication, are known in the art (Ref. 28).
[0036] However, as the aforementioned prior art documents disclose compositions including chelators being intended for their bactericidal or even sterilizing property, said compositions could not be used for the prevention and/or treatment of infections within human body cavities, as their effect would be detrimental also for the lactic acid bacteria and bifidobacteria actually present in the flora of healty individuals.
[0037] To our knowledge, no products combining lactic acid bacteria or bifidobacteria with low molecular weight non-proteinaceous iron chelators are described, or even theoretically suggested, in the prior art.
SUMMARY OF THE INVENTION
[0038] We have now found that selected iron chelating agents incorporated into pharmaceutical or probiotic formulations comprising live lactic acid bacteria or bifidobacteria permit, unexpectedly, the growth of probiotic bacteria while inhibiting the growth of pathogenic microorganisms.
[0039] Accordingly, the present invention relies on a product that combines:
[0040] (a) live bacteria belonging to the natural flora of the body cavity considered, preferably strains of lactobacillus or bifidobacterium species, even more preferably those species selected for their high tendency to bind to mucosal surfaces, and/or to co-aggregate with pathogens, with
[0041] (b) low molecular weight non-proteinaceous iron chelators able to decrease the iron concentration over the physiological pH-range of relevance, to levels that inhibit the growth of pathogens, whilst allowing the growth of the bacteria of the composition.
DETAILED DESCRIPTION OF THE INVENTION
[0042] It is therefore a first aspect of the present invention a pharmaceutical or probiotic composition comprising:
[0043] (a) at least one lactobacillus species and strain or at least one bifidobacterium species and strain, or any mixtures thereof; and
[0044] (b) at least one low molecular weight non-proteinaceous iron chelator.
[0045] The compositions of the invention are particularly advantageous as they may be used in the prevention and/or treatment of pathologies or pathological states due to infections of the human body cavities.
[0046] In the present description, and unless otherwise provided, with the term lactobacillus species and strain and bifidobacterium species and strain we intend those species and strains having a good tolerability in humans and a high affinity for human mucosa.
[0047] Preferably, the lactobacillus strain belongs to the species selected from Lactobacillus johnsonii, Lactobacillus reuterii, Lactobacillus paracasei, Lactobacillus casei, Lactobacillus animalis, Lactobacillus ruminis, Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus fermentum, and Lactobacillus delbrueckii subsp. Lactis.
[0048] Even more preferably, lactobacillus strains are those selected from the group consisting of Lactobacillus johnsonii La1 NCC 2461 (=CNCM I-2116), Lactobacillus reuterii strains 4000 and 4020 (from BioGaia Biologics Inc., Raleigh, N.C.), Lactobacillus paracasei strains CNCM I-1390, CNCM I-1391, CNCM I-1392, Lactobacillus casei strain Shirota, Lactobacillus acidophilus strain CNCM I-1447, Lactobacillus acidophilus Lat 11/83, Lactobacillus acidophilus NCC 2463 (=CNCM I-2623), Lactobacillus rhamnosus GG (ATCC 53103), Lactobacillus rhamnosus 271 (DSMZ 6594) and Lactobacillus rhamnosus VTT E-800.
[0049] As far as the bifidobacterium strain is concerned, it preferably belongs to the species selected from: Bifidobacterium spp., Bifidobacterium bifidum, Bifidobacterium longum, Bifidobacterium pseudolongum, Bifidobacterium infantis, Bifidobacterium adolescentis, and Bifidobacterium lactis.
[0050] Even more preferably, bifidobacterium strains are selected from the group consisting of: Bifidobacterium bifidum NCC 189 (=CNCM I-2333), Bifidobacterium adolescentis NCC 251 (=CNCM I-2168), Bifidobacterium lactis (ATCC 27536), Bifidobacterium breve CNCM I-1226, Bifidobacterium infantis CNCM I-1227, and Bifidobacterium longum CNCM I-1228.
[0051] All the mentioned lactobacilli and bifidobacteria are well known to the skilled person and they may be isolated according to known methods or, in case, they may be obtained directly from the referred bacterial collections.
[0052] Unless otherwise provided, the pharmaceutical or probiotic compositions of the invention may comprise one or more lactobacillus species and strain, or one or more bifidobacterium species and strain, or even any mixture thereof, selected from the aforementioned lactobacilli and bifidobacteria.
[0053] Preferably, however, the compositions comprise at least one lactobacillus species and strain or at least one bifidobacterium species and strain.
[0054] Even more preferably, the pharmaceutical or probiotic compositions of the invention comprise at least one lactobacillus species and strain.
[0055] In the present description, unless stated otherwise, with the term chelator we intend chemical moieties, agents, compounds or molecules, either as such or in the form of pharmaceutically acceptable salts, characterized by the presence of functional groups which are able to form a complex by more than one coordination bond with a transition metal or another metal entity.
[0056] In the specific case, the chelator, otherwise known as chelating agent, according to the invention, is a physiologically acceptable derivative enabling for the formation of an iron coordination complex, acting by that as an iron sequestring agent.
[0057] Most preferred iron chelators are those with a conditional formation constant for iron (III) ions over the pH range of 4.6 to 8.2, of at least 10 15 L/mol, and preferably above 10 17 L/mol.
[0058] With the term physiologically acceptable we intend any chelator suitable for the administration to humans for the intended therapeutic use, in combination with the above lactobacilli and/or bifidobacteria, in any suitable administration routes.
[0059] With the term non-proteinaceous chelator or chelating agent we intend any chelators not having the characterizing structures of proteins, being the definition of protein widely known to the skilled person.
[0060] Typically, the non-proteinaceous chelator of the invention has an average molecular weight (MW) lower than 10 kDa, more preferably lower than 5 kDa and even more preferably lower than 1 kDa, that is well below the average MW of the protein structures (e.g. lactoferrin MW=80 kDa).
[0061] Suitable chelating agents are, for instance, selected from the group consisting of: pyridinone derivatives such as Deferiprone (see The Merck Index, XIII Ed. 2001, No. 2878), hydroxamates such as Desferroxamine B or acetohydroxamic acid; cathecols such as 1,8-dihydroxynaphthalene-3,6-sulfonic acid, MECAMS, 4-LICAMS, 3,4-LICAMS, 8-hydroxyquinoline or disulfocathecol; polyaminopolycarboxylic acids and derivatives thereof comprising, inter alia, ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid) (EDDHA), N-(hydroxyethyl)-ethylenediaminetriacetic acid (HEDTA), N,N′-bis(2-hydroxybenzyl)-ethylenediamine-N,N′-diacetic acid (HBED), N,N′-ethylenebis-2-(O-hydroxyphenyl)glycine (EHPG), triethylene-tetraaminehexaacetic acid (TTHA), diethylenetriamine pentaacetic acid (DTPA), DTPA-bismethylamide, benzo-DTPA, dibenzo-DTPA, phenyl-DTPA, diphenyl-DTPA, benzyl-DTPA, dibenzyl-DTPA, N,N-bis[2-[(carboxymethyl)[(methylcarbamoyl)methyl]ethyl]-glycine (DTPA-BMA), N-[2-[bis(carboxymethyl)amino]-3-(4-ethoxyphenyl)propyl)]-N-[2-[bis(carboxymethyl)amino]ethyl]glycine (EOB-DTPA), 4-carboxy-5,8,11-tris(carboxymethyl)-1-phenyl-2-oxa-5,8,11-triazatridecan-13-oic acid (BOPTA), N,N-bis[2-[bis(carboxymethyl)amino]ethyl]L-glutamic acid (DTPA-GLU) and DTPA-Lys; ethylenediaminotetraacetic acid (EDTA), trans-1,2-diaminocyclohexane; N,N,N′,N′-tetraacetic acid (CDTA), NTA, PDTA, 1,4,7,10-teraazacyclododecane-1,4,7,-triacetic acid (DO3A) and derivatives thereof including, for example, [10-(2-hydroxypropyl)-1,4,7,10-teraazacyclododecane-1,4,7,-triacetic acid (HPDO3A) and corresponding [10-(2-hydroxypropyl)-1,4,7,10-tetraazado decane-1,4,7-triacetato(3-)-N 1 ,N 4 ,N 7 N 10 ,O 1 ,O 4 ,O 7 ,O 10 ]calcinate(1-), calcium (2:1), better known as calteridol or Ca 3 (HPDO3A) 2 , 1,4,7-triazacyclononane-N,N′,N″-triacetic acid (NOTA), 6-[bis(carboxymethyl)amino]tetrahydro-6-methyl-1H-1,4-diazepine-1,4(5H)-diacetic acid (AAZTA) and derivative thereof, 1,4,7,10-tetraazacyclotetradecane-1,4,7,10-tetraacetic acid (DOTA) and derivatives thereof including, among others, benzo-DOTA, dibenzo-DOTA, (α,α′,α″,α′″)-tetramethyl-1,4,7,10-tetraazacyclo-tetradecane-1,4,7,10-tetraacetic acid (DOTMA), and 1,4,8,11-tetraazacyclotetradecane-N,N′,N″,N′″-tetraacetic acid (TETA), or corresponding compounds wherein one or more carboxylic group is replaced by a phosphonic and/or phosphinic group including, for instance, N,N′-bis-(pyridoxal-5-phosphate)-ethylenediamine-N.N′-diacetic acid (DPDP), ethylenedinitrilotetrakis(methylphosphonic) acid (EDTP), 1,4,7,10-tetraazacyclotetradecane-1,4,7,10-tetra(methylenepho sphonic) acid (DOTP); as well as texaphyrins, porphyrins and phthalocyanines.
[0062] Preferred chelating agents according to the present invention include Deferiprone, HPDO3A and derivatives thereof such as, inter alia, calteridol, DTPA and derivatives thereof comprising, for instance, DTPA-Glu and DTPA-Lys; DOTA and derivatives thereof; BOPTA; AAZTA and derivatives thereof; EDTA and derivatives thereof; TETA and derivatives thereof.
[0063] The above listed chelating agents are widely known in the art and may be in case prepared according to known methods. For most of them, in addition, there already exists experience with human use.
[0064] For a general reference to iron chelators see, for instance, Zu D. Liu, Robert C. Hider; Design of iron chelators with therapeutic application; Coordination Chemistry Reviews Volume 232, Issues 1-2, October 2002, Pages 151-171.
[0065] As an example, the iron chelator DTPA in the form of calcium trisodium pentetate (Ditripentat®, Heyl & Co., Berlin, Germany) is used subcutaneously, at daily doses of 0.5 to 1 g for 5 days a week, for the treatment of thalassemia in patients with high-tone deafness caused by deferoxamine (Ref. 32).
[0066] Additionally, although in the form of a salified gadolinium complex, gadopentetate dimeglumine (Magnevist®, Schering AG, Berlin, Germany) is used as a contrast agent for magnetic resonance imaging. Its enteral form contains trisodium pentetate as excipient at a level of 455 mg/L of administrable drink.
[0067] As the maximal recommended dose is 1 L, an oral dose of 455 mg (0.99 mmol) of trisodium pentetate is already being used and proven to be safe, at least for a single administration. The acute oral semilethal dose (LD 50 ) of DTPA in mice is 3500 mg/kg. Thus, DTPA is a safe oral drug, representing a preferred iron chelator for the compositions of the present invention.
[0068] Likewise, the compound 4-carboxy-5,8,11-tris(carboxymethyl)-1-phenyl-2-oxa-5,8,11-triazatridecan-13-oic acid (BOPTA) has been found to have an acute oral LD 50 in mice of 8.4 mmol/kg. It is therefore a further preferred iron chelator for the compositions of the invention.
[0069] For the pharmaceutical use, these chelators may also be formulated as complexes in the form of a pharmaceutical acceptable salt, including neutral salts, such as in particular, calcium complexes. In this direction, in fact, the calcium binding affinity is weak enough to not substantially interfere with the iron binding of pharmacological interest.
[0070] In this respect, another preferred iron chelator in the form of a calcium complex, is calteridol also known as Ca 3 (HPDO3A) 2 and corresponding to [10-(2-hydroxypropyl)-1,4,7,10-tetraazadodecane-1,4,7-triacetato(3-)-N 1 ,N 4 ,N 7 ,N 10 ,O 1 ,O 4 ,O 7 ,O 10 ]calcinate(1-), calcium (2:1), which is used in the intravenous contrast agent formulations of Gadoteridol (see The Merck Index, XIII Ed., 2001, No. 4353).
[0071] The preferred therapeutic or probiotic compositions of the invention can be formulated in different ways, depending on the desired route of administration, according to methods adopted in the pharmaceutical field.
[0072] Preferably, the compositions of the invention may be administered either orally or topically, as reported in more details herein below.
[0073] As an example, said compositions can be formulated as a mixture of components or, alternatively, they can equally be offered as separate pharmaceutical formulations in a single kit, for example for the simultaneous or sequential oral or vaginal administration. Therefore, it is an additional embodiment of the invention a kit of parts wherein a first part comprises at least one lactobacillus species and strain or at least one bifidobacterium species and strain, or mixtures thereof, and a second part comprises at least one low molecular-weight non-proteinaceous iron chelator.
[0074] Non limitative examples of particularly preferred compositions of the invention are disclosed below.
[0075] Compositions for Intestinal Use
[0076] A first embodiment of the invention is represented by the compositions generally intended for gastrointestinal use, to be preferably administered as a drink, a capsule, an infant formula or a dairy product.
[0077] To this extent, the selected bacterial strains may be suitably employed so that the amount of bacteria available to the individual corresponds to about 10 3 to about 10 14 CFU per day, preferably from about 10 7 to about 10 12 CFU per day, and even more preferably from about 10 9 to about 10 12 CFU per day.
[0078] The corresponding amount of iron chelator may range from about 10 −3 to about 10 −9 mol, and preferably from 10 −4 to about 10 −7 mol.
[0079] In case the compositions of the invention should be intended in the form of an oral formulation, they might be offered in any proper form, such as, among others, a milk drink, a yoghurt-similar milk product, a cheese, an ice-cream, a fermented cereal-based product, a milk-based powder, an infant formula, a tablet, a capsule, a liquid suspension, a dried oral grit or powder, a wet oral paste or jelly, a grit or powder for dry tube feeding or a fluid for wet tube feeding.
[0080] Alternatively, the drink may be prepared before use from a dissolvable capsule containing the active ingredients.
[0081] Preferably, the drink may be prepared before use by reconstituting a dry powder containing the lyophilized bacteria and the iron chelator or, alternatively, by reconstituting a dry powder containing the lyophilized bacteria with a physiological solution already comprising the chelator.
[0082] The dry powder is preferably packaged in such a way that the stability of the solid may be retained along the time, such as for instance, into airtight and light-tight sachets, under air or nitrogen, under a noble gas or under vacuum.
[0083] As far as the capsules are concerned, they may be properly manufactured according to conventional methods.
[0084] From all of the above, it is clear to the skilled person that the compositions of the invention may further comprise any additional excipients among those commonly employed in pharmaceutical formulations, in order, for instance, to stabilize the compositions themselves, or to render them easily dispersible or to give them an agreeable taste.
[0085] Among said excipients inulin, fructose, starch, xylo-oligosaccharides, silicon oxide, buffering agents as well as flavors, are suitable examples.
[0086] Furthermore, optional active ingredients may be also present in the compositions of the invention such as, for instance, vitamins, amino acids, polypeptides and the like.
[0087] An example of an optional active ingredient may be represented by glutamine (Ref. 33) which may help intestinal cells to defend themselves under stress conditions due to pathogenic organisms (Ref. 34 and 35).
[0088] Alanyl-glutamine (Ref. 36) as well as a variety of vitamins may also represent additional ingredients within the compositions.
[0089] The presence of transition metals should be preferably avoided so to not impair the binding and/or sequestration of the naturally occurring iron ions by the chelator. However, by considering that the preferred chelators according to the invention bind iron ions much stronger than other physiological transition-metal ions, for instance zinc or copper, the presence of these latter substantially does not affect the efficacy of the present compositions.
[0090] Compositions for Vaginal Use
[0091] According to an additional embodiment, the present invention also provides for a composition intended for the vaginal use, for instance as a compressed vaginal suppository or insert, preferably as a rapidly dissolving type, such as a tampon or a douche.
[0092] Vaginal suppositories and capsules are well-known pharmaceutical formulations. During their manufacturing process, however, special cares should be taken to operate at temperature conditions at which the bacteria may survive, according to methods known in the art (Ref. 4).
[0093] Vaginal inserts are also known in the art and may be manufactured, for instance, by powder compression of maltodextrin beads including the components of the invention (Ref. 4).
[0094] Standard catameneal tampons, and their production methods, can be well adapted for obtaining vaginal tampons bearing the ingredients of the invention on their surface; preferably, the final tampon is packaged in a way suitable for the protection from moisture.
[0095] Vaginal douches are commercially known and generally consist of a product to be locally applied by a proper applicator, hence suitable for the vaginal delivery of the compositions of the invention.
[0096] Clearly, unlike otherwise provided, also the compositions intended for vaginal use may comprise additional excipients among those known in the art (e.g., buffering agents) and/or active ingredients known for formulations of this type.
[0097] The compositions of the invention resulted to be particularly effective in the colonization of the gastrointestinal tract or the vaginal tract and, hence, allow for the restoration of a well functioning microflora, particularly in the case of a previous use of antibiotics.
[0098] It will be self evident to the skilled person, that said compositions may find a wide range of applications either in the maintenance of probiotic bacteria adhering to healthy mucosal surfaces or in the treatment of the infections of the human body cavities such as, e.g., the vaginal tract, the male urethra, the intestine and the buccal cavity.
[0099] Vaginal infections wherein the compositions of the invention may be advantageously used may comprise, as non limiting examples, bacterial vaginosis, symptomatic yeast vaginitis, gonorrhea, chlamydia, trichomoniasis, human immunodeficiency virus infection, urinary tract infection or pelvic inflammatory disease.
[0100] Further, among the pathological conditions of the gastrointestinal tract, the compositions of the invention may be used for the treatment of acute diarrhea in adults and infants, rotavirus-related, travel's or antibiotic-associated diarrhea, and recurrent clostridium difficile colitis.
[0101] Experimental Section
[0102] With the aim of illustrating the present invention, without posing any limitation to it, the following examples are now given.
EXAMPLE 1
[0103] Drink Formulation
[0104] A powder containing lactobacilli and at least one small molecular weight non-proteinaceous iron chelator, suitable for preparing a drink, was formulated to have the following composition:
[0000]
Inulin
145.00
kg
Fructose
57.69
kg
L-glutamine
50.00
kg
Xylo-oligosacchrides
25.00
kg
Lactobacillus paracasei CNCM I-1390
11.13
kg
(3.85 × 10 11 CFU/g)
Orange aroma
10.50
kg
Silicon dioxide
0.40
kg
Pentetate calcium trisodium (DTPA CaNa 3 )
0.21
kg
Vitamin B6 hydrochloride
0.07
kg
Lot
300.00
kg
[0105] Portions of 7 g of this powder were filled into sachets under low humidity conditions and sealed. A single dose of the drink consisted in the content of a sachet suspended in a glass of water.
EXAMPLE 2
[0106] Drink Formulation
[0107] Analogously to Example 1, a powder containing the selected strain of lactobacilli and the small molecular weight non-proteinaceous iron chelator was formulated, wherein the chelator was calteridol, which is [10-(2-hydroxypropyl)-1,4,7,10-tetraazadodecane-1,4,7-triacetato(3-)-N 1,N 4 ,N 7 ,N 10 ,O 1 ,O 4 ,O 7 ,O 10 ]calcinate(1-), calcium (2:1), abbreviated Ca 3 (HP-DO3A) 2 , in the same amount.
EXAMPLE 3
[0108] Drink Formulation
[0109] A powder containing the selected lactobacilli strain and at least one small molecular weight non-proteinaceous iron chelator suitable for preparing a drink was formulated to have the following composition:
[0000]
Corn starch
86.24
kg
Fructose
120.00
kg
L-glutamine
42.87
kg
Xylo-oligosacchrides
30.00
kg
Lactobacillus paracasei CNCM I-1390
11.13
kg
(3.85 × 10 11 CFU/g)
Orange aroma Drycell 01142
9.00
kg
Silicon dioxide
0.33
kg
Deferiprone (1,2-dimethyl-3-hydroxypyrid-4-one)
0.43
kg
Lot
300.00
kg
[0110] Portions of 7 g of this powder were filled into sachets under low humidity conditions and sealed. A single dose of the drink consisted in the content of a sachet suspended in a glass of water.
EXAMPLE 4
[0111] Therapeutic Infant Formulation
[0112] A therapeutic infant formulation was obtained by mixing from 0.5% to 5%, preferably 2%, of polypeptides; from 0.2% to 10%, preferably 4%, of fat; from 1% to 25%, preferably 8%, of non-levan carbohydrates (including lactose 65%, maltodextrin 20% and starch 15%); a proper amount of an iron chelator, and at least 10 6 CFU/mL of the following strain: Lactobacillus acidophilus CNCM I-1447, in combination with traces of vitamins to meet the daily requirements; from 0.01% to 2%, preferably 0.3%, of minerals, and from 50% to 75% of water.
EXAMPLE 5
[0113] Therapeutic Dairy Product
[0114] A yoghurt-like milk product was prepared by the following procedure. One liter of a milk product containing 2.8% of fats and supplemented with 2% of skimmed milk powder and 6% of sucrose was prepared. Then, the product was pasteurized at 96° C. for 30 min according to known methods. A proper amount of calteridol was then added.
[0115] A preculture of Lactobacillus paracasei CNCM I-1390 was reactivated in a medium containing 10% of reconstituted milk powder and 0.1% of commercial yeast extract with 1% sucrose. The pasteurized milk product was then inoculated with 1% of the reactivated preculture and this milk product was then allowed to ferment until the pH reaches a value of 4.5. The resulting therapeutic yoghurt-like milk-product was stored at 4° C.
EXAMPLE 6
[0116] Vaginal Suppository
[0117] In a sterilized blender, 0.12 kg finely ground calteridol was blended with 1.33 kg of polyethylene glycol 1000 (PEG 1000) under nitrogen, during which the polyethylene glycol melts. Under continued mild mixing the calteridol-PEG 1000 mixture was cooled until returned to a semi-solid consistency.
[0118] By intensive mechanical mixing and under vacuum in a cooled container, the following ingredients were admixed:
[0000]
Polyethylene glycol 1000
72.43
kg
Polyethylene glycol 4000
24.48
kg
Lactobacillus paracasei CNCM I-1390
2.00
kg
(3.85 × 10 11 CFU/g)
Calteridol-PEG 1000 mixture
1.09
kg
Lot
100.00
kg
[0119] The resulting mixture was formed into 5 g suppositories by a cooled compression molding technique.
EXAMPLE 7
[0120] Vaginal Capsules
[0121] The procedure substantially follows the one of Example 3 of Ref. 4, with the difference that the maltodextrin beads was first sprayed with an aqueous solution of calteridol sodium and dried in a fluid bed drier, and then sprayed with the bacterial cell matrix suspension.
[0122] A preservation matrix was prepared as follow:
[0123] 2 parts gelatin (e.g., 137.5 g per 500 mL reagent water) and 4 parts skim milk (e.g., 15 g per 250 mL reagent water) were autoclaved at about 121° C. for about 15 min. 4 Parts xylitol (e.g., 59 g per 250 mL reagent water) and 4 parts dextrose (25 g per 250 mL reagent water) were mixed together, the mixture was adjusted to pH 7.2-7.4 and filter sterilized with a 0.22 μm filter. The sterile components were therefore combined into a single solution (gelatin base) and stored at 2-8° C. Ascorbic acid was prepared as a 5% (w/w) solution, filter-sterilized with a 0.22 μm filter and stored at −20° C. At the time of the production of the vaginal medicant, the gelatin base was melted and tempered to about 35° C. Then, the 5% (w/w) ascorbic acid was added to the gelatin base at a ratio of 1:10 to form the preservation matrix solution.
[0124] A solution of calteridol (462 mg/mL reagent water) was prepared and sterilized at 121° C. for 20 min.
[0125] Lactobacillus paracasei CNCM I-1390 is grown as described in Ref. 30 at a cell density of about 5×10 9 cells/mL and a cell pellet was prepared by centrifugation for 5 min at 1400-1600 rpm.
[0126] The cell pellet was resuspended in a phosphate-buffered saline and pelleted again by centrifugation. The cell pellet was resuspended in 1 part of phosphate-buffered saline and 10 parts of preservation matrix solution. The cell matrix suspension was gently mixed and maintained under continuous mixing at 35° C.
[0127] To form the complete vaginal medicant, a fluid bed dryer having sterilized components was assembled for use. Maltodextrin beads (Maltrin® QD M510, Grain Processing Corporation, Muscatine, Iowa) were placed into the fluid bed dryer and dried at 33° C. until a sufficient dryness was achieved. The air pressure was then set to 14 psi, and the solution of calteridol sodium [Ca 3 (HP-DO3A) 2 ] (50 mL per kg of maltodextrin beads) was sprayed onto the beads using a peristaltic pump. The beads were allowed to dry for 30 min at about 38° C. The temperature was decreased to 33° C. and the cell matrix suspension (50 mL per kg of maltodextrin beads) was sprayed onto the beads with the aid of the peristaltic pump. After 50% of the cell matrix suspension was sprayed onto the beads, the temperature was increased to 38° C. After all the cell matrix suspension was sprayed onto the beads, the coated beads were allowed to dry at about 38° C. for about 30 min. In case, the coated maltodextrin beads may be frozen and stored as a powder.
[0128] The powder was filled into gelatin capsules Type 00 to a level of about 500 mg per capsule. One capsule contains about 5×10 8 CFU of lactobacilli.
[0129] The capsules may be packaged, optionally under nitrogen or vacuum, into air and vapor-tight primary packaging material.
EXAMPLE 8
[0130] Vaginal Capsules
[0131] The procedure substantially follows the one of the preceding Example 7, with the difference that the phosphate-buffered saline used in the preparation of the cell matrix suspension was modified to contain 10 mM of a small molecular weight non-proteinaceous iron chelator, preferably calteridol sodium [Ca 3 (HP-DO3A) 2 ], under reduction of the sodium chloride concentration to achieve isotonicity, i.e., about 290 mOsmol/kg.
EXAMPLE 9
[0132] Vaginal Capsules
[0133] Vaginal capsules were prepared essentially as described in present Example 8, except that Lactobacullus paracasei CNCM I-1390 was replaced by the Lactobacullus crispatus CTV-05 described in Ref. 4.
EXAMPLE 10
[0134] Vaginal Insert
[0135] The maltodextrin beads coated with Lactobacullus paracasei CNCM I-1390 were prepared as described in Example 14. Vaginal inserts were prepared by compression.
EXAMPLE 11
[0136] Vaginal Tampon
[0137] A lyophilized powder containing lactic acid bacteria, the chelator and the excipients was prepared.
[0138] A vaginal tampon was prepared composed of an absorbent compressed, cylindrical core of tissue pulp and short rayon fibers. Maximal dryness of the core was assured by placing it in a high vacuum overnight and working in a low humidity environment. The tailing one-third was temporarily wrapped with plastic and the leading two-thirds were covered with the described powder by turning and rubbing it by hand on a flat glass surface. A non-woven cover was wrapped around the core and a withdrawal string was knotted around the core at its trailing end. The finished tampon was packaged under dry nitrogen into airtight and light-tight pharmaceutical sachet.
BIBLIOGRAPHY
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The present invention relates to probiotic compositions and kits thereof, comprising live bacteria belonging to the natural flora of the human body cavity such as intestine and vaginal tract, in particular, strains of lactobacillus or bifidobacterium species, and low molecular-weight non-proteinaceous iron chelators capable of lowering the iron concentration over the whole physiological pH-range of relevance to levels that inhibit growth of pathogens, but which allow for the growth of the bacteria of the composition.
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FIELD OF THE INVENTION
This invention relates to pseudo-random sequence generators.
BACKGROUND TO THE INVENTION
Pseudo-random sequences of integers find many applications, for example in the sampling and simulation technologies. Sampling is an important factor for example in the pharmaceutical, biotechnological, medical and social sciences, and simulation of random events is used in many methods of destruction testing and prototype development in mechanical and civil engineering. Pseudo-random sequence generators also find applications in electronics, computer and communication technologies.
A random sequence is one in which, for all integral values of n, however large, the (n+1)th term in the sequence cannot be determined from knowledge of all the previous terms from the first to the (n)th. For example, data collected from 1,000,000 throws of a conventional six-faced die is of no assistance in determining the result of the 1,000,001th throw.
A pseudo-random sequence is a sequence for which it is perceived to be impossible to determine the (n+1)th term solely from knowledge of all the n previous terms unless n exceeds a very large number. In the state of the art, such a number is of the order of 1×10 190 and there are statistical techniques available, such as the Berlekamp-Massey and the Sloane-Reeds tests which permit a formal judgement of the perception of impossibility. In this context the period of a sequence is the value of C such that, for all values of n, the (n+C) the term is identical to the (n)th term.
An object of the present invention is to make it possible to provide a pseudo-random generator wherein the period can be arranged to be very high while still retaining practical levels of speed and cost.
SUMMARY OF THE INVENTION
According to the present invention there is provided a pseudo-random sequence generator characterised by comprising a plurality of substantially similar elements adapted to operate in parallel, each said element including:
means for entering at least first and second different numbers into that element, and
means for processing said numbers including multiplier means for creating intermediate numbers of higher value than either of said first and second numbers and modulating means having a modulating number for subsequently reducing those intermediate numbers to values below the modulating number, whereby said processing means is adapted to generate a first sequence that has a period not less than half the number range of said first sequence; and
means for combining the first sequence number by number from all the parallel elements to permit generation of a pseudo-random sequence of higher period.
In preferred embodiments of the present invention the use of the combination of multiplying and pipelined modulating algorithms permits each parallel element to generate a pseudo-random sequence with a significantly high period, e.g. of the order of 30,000 in one embodiment when the modulus used for modulating is a prime number of the order of 60,000. This is a convenient level for 16 bit computer operation because 2 16 -1=65,535. The use of a number V of such similar elements operating in parallel permits the combined output pseudo-random sequence to have a period of the order of 30,000 to the power V. Thus the relationship between period and number of parallel elements is as follows:
______________________________________V approximate period______________________________________5 30,000.sup.5 = 2.4 × 10.sup.226 30,000.sup.6 = 7.3 × 10.sup.267 30,000.sup.7 = 2.2 × 10.sup.3120 30,000.sup.20 = 3.5 × 10.sup.8943 30,000.sup.43 = 3.3 × 10.sup.192______________________________________
The highest period currently required in the technological use of randomness is 5×10 189 , and thus 43 parallel elements can fulfil this requirement.
Advantageously there is provided a pseudo-random sequence generator of the type described above characterised by each said element including:
means for entering a third different number into that element,
the means modulating by the third number any number supplied thereto to provide a remainder number,
the multiplier means comprising: first means for multiplying the first number successively by powers of the second number, subjecting each product of this multiplication to said modulation, and storing the results of those successive modulations, and second means for multiplying each said stored result in succession by a predetermined number and subjecting each product of this multiplication to said modulation to create a sequence of numbers at an output of that element; and
the means for combining comprising means for sequentially combining together a different number from the sequence at each said parallel element output to provide a pseudo-random sequence of numbers.
The multiplier means preferably includes third means for multiplying the second number successively by that remainder number created as a result of said modulation of the immediately previous result of such multiplication, and means for storing the final result of those successive multiplications, said final result serving as said predetermined number utilised by said second multiplying means.
Said second means preferably includes means for feeding back each number in said sequences of numbers as it is created to replace a said stored result in said storing means, whereby said second means is provided at its input with an endless supply of numbers for multiplication by said predetermined number and subsequent modulation so that said second means can create an endless said sequence of numbers.
Said modulating means is preferably a pipelined modulator wherein the most significant bit is eliminated in successive stages in the pipeline to leave a said remainder of lower value than said modulating number.
Said combining means is suitably a hierarchy of adding means wherein the (n)th number in the sequences from the parallel element outputs are first added in pairs, then the results are added in pairs until a single number is produced to serve as a basis for the (n)th number in said pseudo-random sequence.
Each said parallel element preferably includes entering means for entering first, second and third different numbers, and preferably the first, second and third numbers of each one of said elements are different from the first, second and third numbers of all the other said elements.
More preferably the third numbers in each element are relatively prime with respect to each number. A series of numbers are `relatively prime` if there is no number, apart from 1, that is a common factor to all of the numbers in the series; e.g. 5,9 and 45. This improves the period of the generated sequence.
An embodiment of 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 schematic block diagram of a pseudo-random sequence generator according to the invention;
FIG. 2 is a schematic block diagram of a parallel element in the generator;
FIG. 3 is a schematic block diagram of a combinatorial system in the generator;
FIG. 4 is a schematic block diagram of a pipelined modulator in each parallel element; and
FIG. 5 is a schematic block diagram of a modulator element in each pipelined modulator.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a pseudo-random generator identified as device 1 comprising a plurality V of elements 2 (2(0), 2(1) up to 2 (2 N-1 )) connected and controlled to operate in parallel and with outputs 8 connected to a combinatorial system 3. A common control and data input 4 is connected to the inputs of all the elements 2 and a device output 5 supplies a pseudo-random sequence from the output of system 3.
FIG. 2 shows one of the V parallel elements 2, which are preferably identical to one another. An input terminal is connected through a register 11 to a pipelined modulator 12, in parallel through a multiplexer 13, register 14, gate 9 and multiplier 17 to the pipelined modulator 12, and in parallel through a register 15, multiplexer 16 and the multiplier 17 to the pipelined modulator 12. The pipelined modulator 12 has four output paths, a first feedback path to the input of multiplexer 16, a second feedback path through a register 20 to the multiplexer 16, a third path to a temporary register 18 having an output connected to the multiplexer 13, and a fourth output path through an output register 19 to one of the V inputs of the combinatorial system 3.
FIG. 3 shows a combinatorial system for an embodiment where the number of parallel elements V is eight. The eight parallel inputs, identified as from parallel elements numbered (0) to (7), are connected to a hierarchy of latched adders. The eight inputs are connected in pairs to four adders 30 whose outputs are connected through four latches 31 in pairs to two adders 32 whose outputs are connected through two latches 33 to a single adder 34 whose output is connected through a latch 35 to the device output 5.
FIG. 4 shows one of the pipelined modulators 12. An input 40 is connected from the multiplier 17 to feed a pipeline of W modulator elements 21, and an output 41 is taken from the end element 21 of the pipeline to the four described output paths from the pipeline. Each modulator element has a second input 42 from a common line 43 connected to the output of the register 11.
FIG. 5 shows one of the W identical modulator elements 21 in each pipeline modulator 12. Each has two parallel inputs 50, 51 and two parallel outputs 52, 53 for supplying respectively least and most significant parts of a data word along the pipeline as will be explained. An output register 25 is connected between the inputs and the outputs. A comparator 22 has inputs A and B from the element input 51 and the input 42 respectively, and an output connected to the first input of an AND gate array 23. The input 42 is connected to a second input of the AND gate array 23 and its output is connected to a first input B of a subtractor 24. The input 51 is connected to a second input A of the subtractor 24. The output of the subtractor is connected to the output register 25.
In operation of the generator, the V parallel elements are first primed, conveniently substantially simultaneously, by entering selected numbers at input 4 and processing the numbers with elements 2 in a priming mode as will be described. When all the elements 2 are primed, they are operated in a run mode in parallel to supply number sequences at their outputs 8 that have periods not less than half the number range of the sequences. The outputs are combined in parallel in any suitable manner, for example by system 3 shown in FIG. 3, to permit generation of a pseudo-random sequence of higher period.
Each parallel element 2 is primed by the following priming sequence described in relation to FIG. 2.
1. A modulating number X is entered at terminal 4 and stored in the register 11. This number X is used by the pipelined modulator 12 as an operator on any number passing along the pipeline and, as shown in FIG. 4, the register 11 is connected to the second input 42 of each modulator element 21 along the pipeline. The modulating number is preferably a prime number in the region of 60,000.
2. A multiplying number Y is entered at terminal 4 and stored both in the register 14, via the multiplexer 13, and in the register 15. The multiplying number can be any number greater than one and less than the modulating number.
3. The multiplying number Y in the register 15 is passed through the multiplexer 16 to the multiplier 17 which operates to multiply Y with the same number Y from the register 14, i.e. Y is squared.
4. The result of this multiplication, Y 2 , is passed through the pipelined modulator 12 and, in this priming mode, the output from terminal 41 is supplied only along the first feedback path to the input of multiplexer 16 and not to registers 18, 19 or 20. At this stage Y 2 is usually less than X and accordingly the output of the pipeline is Y 2 rather than the remainder of Y 2 ÷X.
5. The multiplying number Y in the register 15 is again passed through the multiplexer 16 to the multiplier 17 which operates to multiply Y with the result, at this stage Y 2 , of the first pass through the pipeline as fed back in step 4. This step 5 is repeated the same number of times in total as the number W of the modulator elements 21 along the pipeline.
6. The result of the W repetitions of step 5 is a number which is stored in the temporary register 18. This number will be Y W if that is less than X or a lesser number if Y W exceeds the modulating number X. None of the intermediate results are stored.
7. Register 15 is cleared and a running number Z is entered at terminal 4 and stored in the register 15 in place of the number Y. The running number Z is preferably different from Y and can also be any number greater than one and less than the modulating number.
8. The running number Z in the register 15 is passed through the multiplexer 16 to the multiplier 17 which operates in this step simply to pass the number Z unchanged to the pipelined modulator 12. In this step the gate 9 is put in a state such that the number supplied to the multiplier 17 is equal to the number one.
9. The output from terminal 41 of the pipelined modulator 21 is supplied only along the second feedback path to the register 20 which stores the result of the modulation, i.e. Z, because Z is less than the modulating number X.
10. The running number Z in the register 15 is again passed through the multiplexer 16 to the multiplier 17 which now operates to multiply Z with the number Y from the register 14.
11. The result of this multiplication, (Y×Z), is again passed through the pipelined modulator 12. The output from terminal 41 is again supplied to the register 20 and is also supplied to the multiplier 17 via the multiplexer 16 at which time the gate 9 is held in a state such that its output is the number one, rather than the number Y stored in register 14, thus allowing the number (Y×Z) to pass unchanged through the multiplier 17 and be stored within the registers 25 in the pipelined modulator 12. Steps 10 and 11 are repeated W times with all the previously generated values of (Y n ×Z) modulo X being passed unchanged to the modulator 12 and being stored therein, the resulting W numbers each being temporarily stored in sequence in the register 20.
12. The registers 25 in the successive modulator elements 21 from the bottom of the modulator 12 upwards now hold the sequence of W numbers (Y n ×Z) modulo X in the order of their generation.
13. The number stored in the temporary register 18 in step 6 is transferred via the multiplexer 13 into the register 14. The parallel element 2 is now primed in readiness for the run mode.
When all the parallel elements are primed, they operate in parallel in mutual synchronism in the run mode under the control of a master clock in a manner known to those skilled in the art.
In the run mode, the sequence of W numbers stored in the registers 25 of the W modulator elements 21 are indexed downwards in the pipeline step by step and subjected at each step to a respective step of modulation as shown in FIG. 5 and described below. As each remainder number leaves the bottom of the pipeline at the output 41 it is supplied, in this run mode, both along the first feedback path to the input of multiplexer 16 and also along the fourth output path through an output register 19 to one of the V inputs of the combinatorial system 3. The remainder number is passed through the multiplexer 16 to the multiplier 17 which operates to multiply the remainder number with the number stored in the register 14 from step 13 of the priming mode.
The output register 19 is thus supplied with an endless sequence of numbers, one for each downward indexing step of the pipelined modulator 12. This endless sequence is supplied to the combinatorial system 3 in synchronism with the endless sequence from all the other parallel elements 2. The system shown in FIG. 3 adds the numbers in the illustrated adder hierarchy to produce a pseudo-random sequence at the device output 5 as described above.
The operation of each modulator element 21 in the pipelined modulator 12 will now be described in relation to FIG. 5, which shows an intermediate stage modulator element.
The digital input from the previous stage has its bits split into two portions, the more significant portion D N to D M having the same number of bits as the modulating number X. This portion is compared with the modulating number X in the comparator 22. If it is larger than X then the comparator gives a first or true indication to the AND gate array 23, and if it is smaller than X then the comparator gives a second or false indication to the array 23.
The array 23 effectively multiplies the modulating number X either by one or by zero. The outputs of the array 23 are fed to input B of the subtractor 24 which operates to subtract B from A, i.e. the output of the subtractor 24 is equal to the more significant portion of the input less the modulating number X provided that the input is greater than X. The result of the subtraction is combined in the output register 25 with the unchanged less significant portion of the input and the number to be passed to the next stage modulating element 21 is re-portioned so that the more significant portion is now D N-1 to D M-1 . The number of stages W in the pipelined modulator 12 is always sufficient to reduce any possible output from the multiplier 17 to a value less than the value of the modulating number X, i.e. to complete the modulation down to a proper remainder.
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A pseudo-random sequence generator characterized by comprising a plurality of substantially similar elements adapted to operate in parallel, each said element including: means for entering at least first and second different numbers into that element, and means for processing said numbers including multiplier means for creating intermediate numbers of higher value than either of said first and second numbers and modulating means for subsequently reducing those intermediate numbers to values below the higher of said first and second numbers, whereby said processing means is adapted to generate a first sequence that has a period of not less than half the number range of said first sequence; and means for combining the first sequences, number by number, from all the parallel elements to permit generation of a pseudo-random sequence of higher period.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of the provisional application 62/337,114 filed May 16, 2016.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC OR AS A TEXT FILE VIA THE OFFICE ELECTRONIC FILING SYSTEM
[0004] Not Applicable
STATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR OR JOINT INVENTOR
[0005] Not Applicable
BACKGROUND OF THE INVENTION
(1) Field of the Invention
(2) Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
[0006] The disclosure and prior art relates to pump devices and more particularly pertains to a new pump device for drawing fluids efficiently out of a wall while preventing contaminants from entering the well.
BRIEF SUMMARY OF THE INVENTION
[0007] An embodiment of the disclosure meets the needs presented above by generally comprising a lower housing configured for being positioned within a well. The lower housing includes a bladder therein. The bladder expands to force water within the housing into an outlet of a valve apparatus and the bladder contracts to draw water into the housing. A cylinder and piston fluidly coupled to an inlet of the valve apparatus and the inlet is fluidly coupled to the bladder. A one way valve is positioned within the valve apparatus and fluidly connects an inlet chamber including the inlet to an outlet chamber including the outlet. The one way valve allows water to flow from the outlet chamber into the inlet chamber and restricts water from flowing from the inlet chamber into the outlet chamber. An outlet conduit is fluidly coupled to the outlet of the valve apparatus to carry the water where desired.
[0008] There has thus been outlined, rather broadly, the more important features of the disclosure in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the disclosure that will be described hereinafter and which will form the subject matter of the claims appended hereto.
[0009] The objects of the disclosure, along with the various features of novelty which characterize the disclosure, are pointed out with particularity in the claims annexed to and forming a part of this disclosure.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING(S)
[0010] The disclosure will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
[0011] FIG. 1 is a front view of a water pump assembly according to an embodiment of the disclosure.
[0012] FIG. 2 is a top view of a plate of a one way valve of an embodiment of the disclosure.
[0013] FIG. 3 is cross-sectional view taken along line 3 - 3 of FIG. 2 of an embodiment of the disclosure.
[0014] FIG. 4 is a top perspective of an embodiment of the disclosure of a valve apparatus.
[0015] FIG. 5 is a bottom view of an embodiment of the disclosure of a valve apparatus of an embodiment of the disclosure.
[0016] FIG. 6 is cross-sectional view taken along 6 - 6 of FIG. 5 of an embodiment of the disclosure.
[0017] FIG. 7 is a cross-sectional view of a lower housing of an embodiment of the disclosure of a valve apparatus.
[0018] FIG. 8 is an enlarged view of area “ 8 ” of FIG. 7 of an embodiment of the disclosure of a valve apparatus.
[0019] FIG. 9 is a cross-sectional view of the valve apparatus taken perpendicular to FIG. 8 and through ball valve 50 of an embodiment of the disclosure.
[0020] FIG. 10 is an enlarged view of area “ 10 ” of FIG. 7 of an embodiment of the disclosure.
[0021] FIG. 11 is a side view of an actuator of an embodiment of the disclosure.
[0022] FIG. 12 is a side view of an embodiment of the disclosure of a valve apparatus.
[0023] FIG. 13 is a cross-sectional view taken along line 13 - 13 of FIG. 12 of an embodiment of the disclosure.
[0024] FIG. 14 is a top perspective of an embodiment of the disclosure of an upper housing.
[0025] FIG. 15 is side view of the upper housing of an embodiment of the disclosure.
[0026] FIG. 16 is a front perspective view of a first plate of an embodiment of the disclosure.
[0027] FIG. 17 is a rear view of the first plate of an embodiment of the disclosure.
[0028] FIG. 18 is a front perspective view of a second plate of an embodiment of the disclosure.
[0029] FIG. 19 is rear view of the second plate of an embodiment of the disclosure.
[0030] FIG. 20 is a cross-section showing an outlet fitting of an embodiment of the disclosure.
[0031] FIG. 21 is a cross-section showing the actuator and a piston rod of an embodiment of the disclosure.
[0032] FIG. 22 is a broken cross-section of a cylinder of an embodiment of the disclosure.
[0033] FIG. 23 is a top perspective of a cage of an embodiment of the disclosure.
[0034] FIG. 24 is a top view of the cage of an embodiment of the disclosure.
[0035] FIG. 25 is a side view of the cage of an embodiment of the disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0036] With reference now to the drawings, and in particular to FIGS. 1 through 25 thereof, a new pump device embodying the principles and concepts of an embodiment of the disclosure and generally designated by the reference numeral 10 will be described.
[0037] As best illustrated in FIGS. 1 through 25 , the water pump assembly 10 generally comprises a lower housing 12 that is positionable into a well and which includes an upper end 13 , a lower end 14 and a perimeter wall 15 extending between the upper 13 and lower 14 ends. The lower end 14 includes a one way valve 16 for allowing water (or other fluid and hereafter fluid is being used to designate any fluid and in particular any liquid being moved with the assembly 10 ) into the lower housing 12 but restricting water from leaving through the lower end 14 . As can be seen in FIGS. 2, 3 and 10 , the one way valve 16 includes a plate 17 with a plurality of apertures 18 extending therethrough on top of which a gasket 19 is mounted so that as a vacuum is formed within the lower housing 12 , the edge of the gasket 19 lifts to allow water or other fluid to enter the lower housing 12 through the apertures 18 and around the flexible gasket 19 . However, not shown, a pump may be attached to the plate 17 without the gasket and used for powered movement of fluids into the lower housing 12 .
[0038] Within the lower housing 12 is a bladder 20 attached to the upper end which is filled and emptied during the operation of the assembly 10 . As the bladder 20 is filed it moves toward the lower end 14 to drive fluid within the lower housing 12 outwardly of the upper end 13 . As the bladder 20 retracts away from the lower end 14 , a vacuum is created within the lower housing 12 to pull fluid through the one way valve 16 . The bladder 20 comprises a structure which restricts stretching in any direction but longitudinally from the upper end 13 to the lower end 14 of the lower housing 12 .
[0039] A valve apparatus 22 shown in FIGS. 4-6, 8 and 9 and is attached to the upper end 13 of the lower housing and is in fluid communication with the lower housing 12 and bladder 20 . The valve apparatus 22 includes an inlet 23 fluidly coupled to the bladder 20 and an outlet 24 for receiving a fluid from the lower housing 12 . The valve apparatus 22 includes an inlet chamber 25 fluidly coupled to the inlet 23 and an outlet chamber 26 fluidly coupled to the outlet 24 . The inlet chamber 25 is in fluid communication with a cylinder 27 and piston 28 (shown in FIG. 6 ) for forcing fluid downwardly into the bladder 20 as well as pulling fluid outwardly of the bladder 20 . As can be seen in FIG. 8 , the inlet chamber 25 is fluidly coupled to a connector 29 which in turn is fluidly coupled to a supply line 30 at the bottom of the cylinder 27 which includes a threaded male connector as shown in FIG. 12 for attachment to the supply line 30 . The supply line 30 is in fluid communication with the cylinder 27 such that fluid is forced into the supply line 30 when the piston 28 is moved downwardly and then the fluid is then moved into the bladder 20 to expand the bladder 20 and drive water into the outlet 24 . When the piston 28 is moved upwardly a vacuum is created within the cylinder 27 to draw the fluid outwardly of the supply line 30 and the bladder 20 to retract the bladder 20 .
[0040] The cylinder 27 is mounted to a plate 31 , or plates 31 , 32 and covered with an upper housing 33 . The upper housing 33 includes an actuator 34 mounted thereto which is attached a piston rod 35 of the piston 28 . The actuator 34 may include conventional handle 36 as shown in FIG. 1 which is pivotally coupled to the upper housing 33 . However, FIG. 13 shows attachment points 37 for the actuator 34 so that the actuator 34 may be coupled to a motor or windmill to drive the piston 28 . Moreover, it should be understood that the upper housing 33 and the components directly attached thereto may be positioned up to several hundred feet from the valve apparatus 22 and lower housing 12 and may not be positioned directly over the lower housing 12 as shown in FIG. 1 . FIGS. 16-20 show that plates 31 and 32 may be used so that the upper housing 33 may be removed along with plate 32 while leaving the cylinder 27 in place.
[0041] As can be seen in FIG. 8 , a lumen 40 is formed between and fluidly couples the inlet chamber 25 and outlet chamber 26 . The lumen 40 is angled upwardly from the outlet chamber 26 to the inlet chamber 25 and includes a one way valve 41 , which may be formed by a ball, to prevent flow of fluid from the inlet chamber 25 to the outlet chamber 26 . When fluid pressure increases within the lower housing 12 , the fluid is driven upwardly into the outlet chamber 26 and a small amount of the fluid in the outlet chamber 26 is pushed through the lumen 40 and into the supply line 30 where it can be used for filling the cylinder 27 , supply line 30 and bladder 20 in a process of “priming” the assembly 10 .
[0042] As can be seen in FIG. 22 , which is a detail of a cross-section of a portion of the cylinder 27 , the cylinder 27 has an inner surface with a depression 42 therein which may have a depth of less than 0.02 inches and height of less than 1.0 inches, though the height is greater than a seal formed between the piston 28 and the cylinder 27 . The width of this depression is typically less than 0.1 inches. Since the depression 42 has a height greater than the seal between the piston 28 and cylinder 27 , when the piston 28 travels downwardly to drive fluid into the supply line 30 and cylinder 27 , fluid moves between the piston 28 and the cylinder 27 via the depression 42 . This fluid forms a pool on top of the piston 27 to retain pressure within the system and, importantly, prevents contaminated fluid and debris from moving around the piston 28 and back down into the well. The one way valve 41 further prevents contaminated fluid from entering the lower housing 12 . Thus, the piston 28 , cylinder 27 and supply line 30 are effectively sealed off from the outlet chamber 26 .
[0043] As can be seen in FIG. 8 , the outlet chamber 26 includes a ball valve 50 which prevents fluid from moving back into the lower housing 12 . Additionally, when the piston 28 is creating a vacuum in the cylinder 27 , any fluid positioned within the outlet chamber 26 between the ball valve 50 and an exit opening 51 will be drawn through the lumen 40 if there is sufficient negative pressure within the inlet chamber 25 . A cage 52 , shown in FIG. 9 is placed within the outlet chamber 26 to prevent the ball valve 50 from closing the exit opening 51 .
[0044] An outlet fitting 53 is fluidly coupled to the exit opening 51 and an outlet conduit 54 coupled to the outlet fitting 53 . The outlet conduit 54 may be directed where needed to deliver the fluid, though it may be fluidly coupled to a spigot 56 mounted on the upper housing 33 . As can been seen in FIGS. 13 and 20 , the outlet conduit 54 would be connected to an outlet fitting 55 which would remain with the plate 31 should plate 32 and upper housing 33 be removed. As fluid is forced outwardly of the lower housing 12 by the bladder 20 expanding, it moves through the outlet chamber 26 , around the ball valve 50 , into the outlet conduit 54 and finally outwardly of the spigot 56 .
[0045] With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of an embodiment enabled by the disclosure, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by an embodiment of the disclosure.
[0046] Therefore, the foregoing is considered as illustrative only of the principles of the disclosure. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the disclosure to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the disclosure. In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be only one of the elements.
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A water pump assembly includes a lower housing configured for being positioned within a well. The lower housing includes a bladder therein. The bladder expands to force water within the housing into an outlet of a valve apparatus and the bladder contracts to draw water into the housing. A cylinder and piston fluidly coupled to an inlet of the valve apparatus and the inlet is fluidly coupled to the bladder. A one way valve is positioned within the valve apparatus and fluidly connects an inlet chamber including the inlet to an outlet chamber including the outlet. The one way valve allows water to flow from the outlet chamber into the inlet chamber and restricts water from flowing from the inlet chamber into the outlet chamber. An outlet conduit is fluidly coupled to the outlet of the valve apparatus to carry the water where desired.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of utility application U.S. patent application Ser. No. 12/243,772 which claims priority to and the benefit of the filing of U.S. Provisional Patent Application Ser. No. 60/976,978, entitled “An ALPU with Reduced Internal Data Movement and Multiple Match Support”, filed on Oct. 2, 2007. Both of the aforementioned applications are incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was developed under Contract DE-AC04-94AL8500 between Sandia Corporation and the U.S. Department of Energy. The U.S. Government has certain rights in this invention.
INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not Applicable.
COPYRIGHTED MATERIAL
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention (Technical Field)
The present invention relates to associative list processing units (ALPUs), particularly those used in handling Message Passing Interface (MPI) data packets.
2. Description of Related Art
Note that the following discussion refers to a number of publications by author(s) and year of publication, and that due to recent publication dates certain publications are not to be considered as prior art vis-a-vis the present invention. Discussion of such publications herein is given for more complete background and is not to be construed as an admission that such publications are prior art for patentability determination purposes.
The present invention provides improvements to the associative list processing unit (ALPU) described in K. D. Underwood, et al., “A hardware acceleration unit for MPI queue processing”, 19th International Parallel and Distributed Processing Symposium (April 2005), which is incorporated herein by reference. One improvement optimizes the entry management scheme to minimize internal data movement. The second allows the unit to report all matches from a request in priority order, instead of providing only the highest priority match.
BRIEF SUMMARY OF THE INVENTION
The present invention is of an associative list processing unit and method comprising employing a plurality of prioritized cell blocks and permitting inserts to occur in a single clock cycle if all of the cell blocks are not full. In the preferred embodiment, each cell block employs a counter indicating the number of free lower priority cells. Each counter is initialized to the total number of cells with lower priority. The invention further comprises decrementing each counter for each insert to a lower priority cell block and incrementing each counter for each delete from a lower priority cell block.
The present invention is further of an associative list processing unit and method comprising employing a plurality of prioritized cell blocks and using a tree of prioritized multiplexers descending from the plurality of cell blocks. In the preferred embodiment, first-in first-out queues follow each multiplexer. Each multiplexer is an asynchronous, stateless circuit passing through the highest priority valid input. The invention can operate either in single-match mode or in multiple-match mode.
Further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more preferred embodiments of the invention and are not to be construed as limiting the invention. In the drawings:
FIG. 1 is a block diagram of the priority multiplexer of the invention;
FIG. 2 is a block diagram of the two-level priority multiplexer tree of the invention; and
FIG. 3 is a flow diagram of the entry management improvement of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is of an apparatus and method providing improvements to APLUs, particularly those used with MPI. A first improvement provides greatly improved entry management, while the second reports all matches in priority order.
The goals of the entry management improvement are minimizing the number of entry moves and maximizing the availability for new entry insertion. Another important aspect of the preferred implementation is the need to localize control in order to keep operating frequency high. In the original implementation described in the references cited above, control was localized by allowing each cell block to have information about only the lowest priority cell in the next higher priority cell block. The consequence of this was that an insert may have to stall while the entries are moved in order to make room in the lowest priority cell. In order to improve insert availability, the ALPU would compact (move entries to higher priority cells) when the unit was in insert mode and no matching or inserts were currently taking place. In addition, a delete would cause all cells lower than the deleted cell to move one entry up, leaving the lowest priority cell free. The result of this scheme was that inserts were only guaranteed to be able to complete every other clock cycle, although, under certain circumstances, inserts could complete every clock cycle. More importantly, the unit could potentially move much more data than was necessary.
The preferred management scheme of the invention provides the minimum number of moves for all combinations of inserts and deletes, and allows inserts to always happen without delay (as long as the unit is not full), while still maintaining locality in the control logic. Because the improved scheme uses the minimum number of moves, it will use the lowest possible power for managing the list entries. This is done by having each block maintain more information about the global state of the unit. In particular, each cell block maintains a counter (referred to hereafter as the free counter) which tracks the number of entries which are free in lower priority blocks (items enter the unit at the lowest priority block and proceed to higher priority blocks as more items are inserted). A flow diagram of the preferred apparatus and method of the invention is given in FIG. 3 .
The free counter is maintained using only the global insert and delete signals (which are registered as they are fanned out as described in the references above). On power-up or reset, the free counter in each block is initialized to the total number of cells in blocks with lower priority (e.g., if the block size is 8, then the free counter in block 0 is set to zero, block 1 to 8 , block 2 to 16 , etc.). Thereafter, the counter is decremented for each insert and incremented for each delete which occurs in a lower priority block. The counter “saturates” at zero so that it will never go negative, as one cannot have a negative amount of free space.
The entry management control is localized to the cell block and uses the block's free counter as well as the valid signals from all cells in the block. On a delete, the valid bit for the deleted entry is set to zero and the free counter is modified as explained above; thus, there is no longer any data movement on a delete. On an insert, all entries below the lowest priority free cell are moved up one entry to make room for the insert. The blocks handle this by dealing with three cases:
Case 1: When the free counter is greater than 0, there is room in lower priority block to “absorb” the insert, therefore the current block does nothing.
Case 2: When the free counter is equal to 0 and at least one of the cells in the block is empty, the block “absorbs” the insert by moving up all entries below the empty cell (including accepting the highest priority entry from the previous block to the lowest priority cell in the current block). Entries above the first empty cell in the block are not affected.
Case 3: When the free counter is equal to 0 and no cell in the block is empty, the insert must be “absorbed” in a higher priority cell. The current block simply moves all entries up one cell. This includes moving the top entry to the next higher block and accepting the top entry from the previous block into the lowest cell in the current block. There is guaranteed space in a higher priority cell because the ALPU maintains a count of the total number of entries in the unit and disallows inserts when the unit is full.
The preferred multiple match mode of the invention is important for providing flexibility. This mode can allow the ALPU to act as a filter to narrow potential matches when all the matching information cannot be stored in the ALPU. This case can arise for three main reasons: first, not all match information can be formulated as a ternary match; second, including all the necessary match bits would require too much area; and third, protocol changes after the hardware is produced create either of the first two cases.
In multiple match mode, auto-delete is turned off; the actual process of deletion remains the same (the cell to be deleted is specified by its cell address), but is initiated by an external source. This change requires a change only at the highest level control state machine. However, actually re-porting all the matches requires two other changes to the original structure. In the original implementation, simple muxes (multiplexers) were used to select the input with the highest priority at each level. The result was a single output which was the highest priority match. In the inventive mode, all valid matches must be reported in order from highest priority to lowest. This is accomplished by replacing the simple muxes and registers of the prioritization tree with priority muxes and fifos (first-in first-out queues). The second preferred change is a modification to the ternary cell valid bit. Since the priority mux requires the inputs to be stateful (the priority mux must be able to “read” from an input), the match bit logic in the ternary cell must be modified to allow a read (which causes the match bit to deassert). This allows the priority mux to pass each match once (and only once) in priority order.
The priority mux is an asynchronous, stateless circuit which passes through the highest priority valid input. A block diagram of the priority mux is shown in FIG. 1 . The priority mux can have any number of input ports (though in the ALPU, it is best to have a power of two in order to easily compute the address of each match). Each input port comprises three signals: data, valid and read. The valid signal is asserted by the input when valid data is available and the read signal is asserted by the priority mux when the data from that port is passed through to the output and there is space available in the output fifo. The output port also consists of three signals: data out, space available and write. Space available is asserted by the output target when it can accept data and the write signal is asserted when the priority mux writes to the output (this occurs when there is valid data on any of the inputs and there is space available in the output fifo). In addition, the priority mux provides the selected input number as an output to facilitate the generation of the address of each match.
For small ALPUs, a single level of priority muxing may be enough to create the outputs and still maintain the desired operational frequency. For larger sizes which cannot do this, multiple levels of muxing will be necessary to produce the results. In this case, the priority muxes are connected in a tree structure. The first level muxes will select outputs directly from the ternary cells. All succeeding levels will pull their inputs from the previous level of muxes. The output of each level of muxing is fed into a fifo. The fifos allow lower priority paths to block while waiting to be transmitted by the priority mux and needs two entries in order to ensure no “bubbles” in the output of the tree. Because of the fifos used between stages, each stage requires a clock cycle to complete. Thus, the size of the muxes can be adjusted to balance operational frequency and latency (bigger muxes mean lower latency, but also lower operational frequency). A block diagram of a two level priority mux tree is shown in FIG. 2 . Note that the tree can be configured with any number of levels, two is shown for simplicity.
The priority mux tree provides all matches in priority order. The first result arrives at the output after a latency in clock cycles equal to the number of levels in the tree. Thereafter, a new result arrives each clock cycle until all results are reported. For convenience, an “end of list” entry is sent after all valid matches (or in the case of no valid matches, it is the only result returned). This value is denoted by adding an extra bit to the data (e.g., tag) width which is set to one for the end of list and to zero otherwise. This result is generated by adding a phantom cell (i.e., there is no corresponding physical cell) which has a logical lower priority than the lowest priority cell. This is done by adding an extra input to the mux which selects from the lowest priority cells in the unit. This new input is considered to be the lowest priority input, but is not considered when generating the address of the matching cell (i.e., the other inputs are still labeled 0 through N). Having the lowest logical priority, this end of list entry will always be the last result passed to the output.
It is desirable to allow the unit to clear current matches without having to flush all the results through the output fifo. This makes it possible to complete a match operation early when an early entry is found to be the desired match. This in turn reduces the time before the next match can be initiated. This can be done by adding a flush signal to the ternary cells and to the fifos in the mux tree. When asserted, the fifos will go back to their empty state and the ternary cells will deassert all their match signals.
A single associative list processing unit can support both the original single match mode and the new multiple match mode; a mode bit is used to determine which mode is active at any given time. Multiple match mode acts as described (in particular, auto-deletion would be turned off). Single match mode returns only the first match and then uses the flush signal to remove all other matches from the mux tree. Single match mode also has the option of initiating an auto-delete on the matched item. The auto-delete behavior could be controlled by a mode bit or could be enabled automatically whenever single match mode was active, depending on the implementation.
Another way to minimize data movement is to relax the requirement that relative position in the ALPU determines priority. This may be done for multiple reasons: first, it may reduce the overall power requirements of the unit (with the caveat that it may increase silicon area). Second, it may be desirable to use existing TCAM (ternary content addressable memory) IP, which would not include the required ordering semantics of the ALPU, as a basis for the design. The main difference with this type of design is that an ALPU entry would be allowed to be inserted at any position in the unit, and would never move from that position. The consequences of this are described below.
In this scenario, the core of the ALPU is a traditional TCAM structure. The match and mask information are stored in the TCAM, and the ternary match operation is computed in the TCAM. The output of the TCAM is a single bit for each entry identifying which entries matched the request. Auxiliary memory elements (likely registers, but possibly SRAMs) would store the other required information: tag, valid and priority. The tag serves the identical purpose as in a traditional ALPU structure. The valid bit is used both during a match and an insert. During a match, the valid bits indicate which cells hold valid data and positive match results on invalid cells are ignored, thus, a cell can be deleted simply be setting the valid bit to invalid (of course, it is also possible to delete the entry out of the TCAM). During an insert, the ALPU uses the valid bit information to determine which address to load the new data into. The priority of each cell is used to determine the highest priority cell in the case of multiple matches in the TCAM. The highest priority match is found by pair wise comparison of the match results (ignoring those results with the valid bit set to invalid). At each stage, the higher priority match is selected and passed through the mux to the next stage. The result of the muxing is a single result which is the highest priority match.
The priority of each cell must be tracked through insertions and deletions. There are two main ways to track priorities. The first is to keep a simple counter to track the priority of inserted elements; inserted elements are assigned the current value of the priority counter, and the counter is incremented in preparation for the next insert. In this case, priority is given to smaller numbers (of course, priority could be given to larger numbers, in which case the priority counter would be decremented with each insert). This would require a priority field that has many more possible values than there are cells in the ALPU. While this method is straightforward, it has two disadvantages. First, the bit-width of the comparisons to determine priority is larger than strictly necessary. Second, at some point, the counter will need to wrap from maximum value back to zero (or zero back to maximum value in the case of larger numbers having priority), at which point the existing priorities would need to be adjusted appropriately. This operation is non-trivial and could consuming a lot of time, so is likely to have performance implications.
The second method is to set each cell's priority at insertion time based on the number of current valid entries in the ALPU. In this case, each cells priority is updated with each delete that takes place. The priority counter in this case would be updated for both inserts and deletes and would only need to have enough bits to represent values up to the number of cells in the ALPU. Individual cells update their priority whenever a cell with higher priority is deleted; this is done by setting its priority to the next highest value. This results in an increment or a decrement depending on whether high or low values have priority; either of these schemes can be used, depending on the physical implementation of the unit. The advantages of this scheme is that the priority field need only have as many possible values as the number of cells in the unit (thus, minimizing bit width) and it avoids the issues of wrap around. The disadvantage is that each cell now requires a comparator to detect when a higher priority cell is deleted, and an incrementor or decrementor to adjust the priority of the cell. This will have impact on the silicon area of the unit. This area increase can be mitigated by having multiple cells share these structures; of course, this will have some impact on the performance of deletes as it will now take multiple cycles in order to adjust the priorities for all the cells (this is probably tolerable as long as only a small number of cells share these structures).
The idea of sharing resources can also be extended to the muxing logic used to find the highest priority. In this instance, the ALPU is broken into blocks, where each block shares the logic for adjusting priorities, as well as for comparing priorities after a match. There are positive and negative aspects to this type of arrangement. On the positive side, this arrangement allows the priorities and tags to be stored in SRAM cells at the block level, instead of registers, as only one value is needed at a time, resulting in dramatic area savings. The negative side, of course, is that it now takes more time to complete a match operation since some of the parallelism has been removed.
Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference.
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An associative list processing unit and method comprising employing a plurality of prioritized cell blocks and permitting inserts to occur in a single clock cycle if all of the cell blocks are not full.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The disclosed invention generally relates to the Internet architecture and specifically to many interconnected Software Defined Network (SDN) domains, each domain spanning a different administratively-managed network or Autonomous System (AS) which is comprised of at least one controller and many forwarders. Provisioning of an end-to-end path with specific service levels over the Internet requires establishing a, so called, service-enabled flow-path traversing multiple SDN domains. According to an aspect of this invention, in order to enable an SDN controller to determine such a flow-path autonomously, each SDN controller must periodically advertise its service-enabled paths to other SDN controllers. In particular, this invention relates to a system and method for dynamically constructing a service-enabled flow-path, wherein said service can be Quality of Service (QoS) enabled path, a highly reliable path or a highly secure path service, that traverses many such domains between sender(s) and receiver(s), and requires a transport path with certain quantitative or qualitative service level requirements (e.g., low price, high throughput, low packet loss, high availability and/or low packet delay). More specifically, the invention relates to how SDN controllers of different domains share summarized topology information on service-enabled paths in their respective networks with other SDN controllers so as to enabling an autonomous decision-making for an end to end flow-path in real-time by each SDN controller (in contrast to a per-hop path determination of the current public Internet). Doing so, an SDN controller is presented with several service-enabled path alternatives via another SDN domain (or domains) to choose from or to negotiate with other SDN controllers. The invention also describes a system and method for computation of an optimal path for a flow using such advertised summarized topology information. It also covers possible protocols by which an SDN controller can share summarized topology information with other SDN controllers, and reserve and release an end to end flow traversing other SDN controllers' networks.
[0003] 2. Discussion of Related Art
[0004] U.S. Patent Application 2008/026187 teaches a method for providing Virtual Private Network (VPN) services across Autonomous Systems using MPLS protocol. It does not, however, address SDN networks or dynamic flow path determination by using a network graph.
[0005] U.S. Pat. No. 8,724,514 teaches a novel method for controlling the advertisement of routing data to neighbor routers to enhance BGP. A router can receive and propagate reachability data (prefixes) learnt from its neighbor routers' neighbors, and hence enable construction of a full or partial network graph. However, this patent does not address how such data will be used to construct flow paths.
[0006] U.S. Patent Application US 2014/0307556 describes a control plane functionality to configure data plane in SDN networks using a logical topology representation, and a mapping from the logical (abstracted) topology to actual SDN nodes. The logical topology can be determined by a customer, whereas the mapping from that topology to physical SDN nodes is determined using a control plane functionality.
[0007] However, such prior art fails to teach various aspects of Applicants' invention as: (i) there is no need to use an orchestrator or an equivalent higher-level authority then the SDN controllers; (ii) that is all negotiations between multiple operators are carried out with machine-to-machine between SDN controllers.
[0008] Embodiments of the present invention are an improvement over prior art systems and methods.
SUMMARY OF THE INVENTION
[0009] This invention relates to dynamically setting up and tearing down service-enabled flow-paths across multiple SDN domains. An SDN controller of a domain periodically shares with other SDN controllers (of other domains) availability of service-enabled paths (aka, a summarized topology) of its respective network as well as associated service parameters of each path segment using a global nomenclature (aka, a dictionary) with other SDN controllers so as to enable each controller to understand and interpret the shared data in the same manner. Doing so, each SDN controller can autonomously construct a complete network graph of available service-enabled paths across a wide-area network of many domains. This feature is unique to SDN networks since the current public Internet has only knowledge of next-hop's (a ‘hop’ is a ‘domain’ in the inter-domain SDN routing case) network resource availability. Another unique aspect of this invention is the use of summarized (internal) topology of each domain as opposed to just using the peering-link related service information to compute desirable path alternatives. An SDN controller can stitch summarized topology links and peering links to produce a graph with many flow-paths across the Internet, and determine the best path amongst them. The invention describes how this information is shared, how the best path is computed, and how that path is reserved and released across many domains through communications between SDN controllers.
[0010] When an application, such as video streaming, requires a QoS enabled path across multiple domains between the source and destination (where source is, for example, a computer sending a video and destination is another computer receiving that video), the destination network's SDN controller can calculate the best possible QoS-enabled flow path towards the source, based on the most recent service-topology information communicated to it by all other SDN controllers in the network. Similarly, an application may require a highly secure or a highly reliable path (or both) for a top-secret military application. The SDN controller can determine such a flow path based on information shared by other controllers. Said communication can be performed periodically or even on a per-event basis (i.e., when changes occur in the network conditions). Once such a determination is made, the destination network's SDN controller sends a sequence of signaling messages using Internet Protocol (IP) to SDN controllers along the determined path to reserve the resources on that calculated best path. The signaling may also be used to renegotiate service parameters during the lifetime of the flow or just to it tear down.
[0011] In one embodiment, the present invention provided an Internet protocol (IP) based network system with inter-domain topology sharing comprising: (a) a first software defined network (SDN) domain comprising a first controller, a first set of forwarders, and a first storage; (b) a second SDN domain comprising a second controller, a second set of forwarders, and a second storage; (c) the first storage storing first domain topology information associated with the first SDN and second domain topology information associated with the second SDN and advertised by the second controller, (d) the second storage the storing second domain topology information associated with the second SDN and first domain topology information associated with the first SDN advertised by the first controller, and (e) wherein each of the first and second controllers autonomously determining an end-to-end flow path for traversal between the first and second SDN domains based on stored topology information.
[0012] In another embodiment, the present invention discloses a method as implemented in a first controller in a first software defined network (SDN) comprising: storing first domain topology information associated with the first SDN in a first database; transmitting a first advertisement message to a second SDN controller in a second SDN domain, the first advertisement message comprising the first domain topology information associated with the first SDN, and receiving a second advertisement message from a second SDN domain controller in the second SDN domain, the second advertisement message comprising second domain topology information associated with the second SDN; storing the received second domain topology information associated with the second SDN in the first database, and wherein the first controller autonomously determining an end-to-end flow path for traversal between the first and second SDN domains based on stored topology information in the first database.
[0013] In yet another embodiment, the present invention discloses a first software defined network (SDN) controller that is part of a first SDN domain and operable on an Internet protocol (IP) based network system comprising: (a) a service topology information base sub-system storing data of available service enabled paths and associated service metrics between end points in the first SDN domain and a second SDN domain constructed based on service topology information gathered by the first SDN controller and service topology messages advertised by a second SDN controller associated with the second SDN domain; (b) a flow path constructor sub-system determining an end-to-end flow path between the end points based on both multiple service path topology alternatives stored in the service topology information base sub-system and a pre-determined algorithm (e.g., heuristic algorithm, approximation algorithm, and Lagrangian relaxation based aggregated cost (LARAC) algorithm); and (c) a resource reservation sub-system communicating with the second controller in the second SDN domain to reserve, negotiate or release the end-to-end flow path. The SDN controller may also have any of the following features: a flow tracker sub-system to monitor and track the end-to-end flow path once activated, a topology summarizer sub-system to determine a summarized service-enabled topology/graph of the first SDN domain to be communicated to the second controller in the second SDN domain, and/or a topology communicator sub-system to advertise summarized service-enabled topology/graph of the first SDN domain to the second controller in the second SDN domain.
[0014] The present invention also discloses a non-transitory computer-readable medium containing instructions that, when executed by a processor in a first controller in a first software defined network (SDN), cause the first controller to: store first domain topology information associated with the first SDN in a first database; transmit a first advertisement message to a second SDN controller in a second SDN domain, the first advertisement message comprising the first domain topology information associated with the first SDN, and receive a second advertisement message from a second SDN domain controller in the second SDN domain, the second advertisement message comprising second domain topology information associated with the second SDN; store the received second domain topology information associated with the second SDN in the first database, and autonomously determine an end-to-end flow path for traversal between the first and second SDN domains based on stored topology information in the first database.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The present disclosure, in accordance with one or more various examples, is described in detail with reference to the following figures. The drawings are provided for purposes of illustration only and merely depict examples of the disclosure. These drawings are provided to facilitate the reader's understanding of the disclosure and should not be considered limiting of the breadth, scope, or applicability of the disclosure. It should be noted that for clarity and ease of illustration these drawings are not necessarily made to scale.
[0016] FIG. 1 illustrates a high level diagram of a prior art network comprised of two interconnected SDN domains.
[0017] FIG. 2 illustrates an exemplifying connectivity of control and data planes of four prior art interconnected SDN domains.
[0018] FIG. 3 illustrates an exemplifying topology of four interconnected prior art SDN domains.
[0019] FIG. 4 illustrates an exemplifying summarized topology of four interconnected SDN domains as perceived by Domain G 1 according to this invention.
[0020] FIG. 5 illustrates a block diagram of an SDN Controller's software subcomponents according to this invention, enabling an end-to-end service-enabled flow path establishment across multiple domains.
[0021] FIG. 6 illustrates an example flowchart outlining the steps of one SDN controller collecting summarized topology information from other SDN controllers.
[0022] FIG. 7 illustrates an example flowchart outlining the steps of calculating, reserving, tracking and finally releasing a flow-path across multiple SDN domains.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] While this invention is illustrated and described in a preferred embodiment, the invention may be produced in many different configurations. There is depicted in the drawings, and will herein be described in detail, a preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and the associated functional specifications for its construction and is not intended to limit the invention to the embodiment illustrated. Those skilled in the art will envision many other possible variations within the scope of the present invention.
[0024] Note that in this description, references to “one embodiment” or “an embodiment” mean that the feature being referred to is included in at least one embodiment of the invention. Further, separate references to “one embodiment” in this description do not necessarily refer to the same embodiment; however, neither are such embodiments mutually exclusive, unless so stated and except as will be readily apparent to those of ordinary skill in the art. Thus, the present invention can include any variety of combinations and/or integrations of the embodiments described herein.
[0025] SDN is a new approach for IP networking that allows decoupling of control and data planes. Decisions about traffic routing are performed at the control plane, while traffic forwarding according to the rules determined by the control plane is performed at the data plane. An SDN Controller is the software where control plane decisions are performed. It nay reside in a single computer or may be distributed to many computers,
[0026] SDN applications are written in or on the SDN controller, which enable management of data plane routes differently based on specific application needs.
[0027] SDN controller is a logically centralized entity in charge of (i) translating the requirements from the SDN application down to the data path and providing applications with a summarized view of the network (which may include statistics and events). It is mainly comprised of a control Logic, a control to data-plane interface, and an API set for applications to use or program SDN controller. Definition as a logically centralized entity neither prescribes nor precludes implementation details such as the federation of multiple controllers, the hierarchical connection of controllers, communication interfaces between controllers, nor virtualization or slicing of network resources. A possible control-to-data-Plane interface is OpenFlow defined by the Open Networking Foundation, ONF.
[0028] The SDN data plane is where forwarding and data processing is performed. A data plane entity s a so called forwarder, which contains one or more traffic forwarding engines with traffic processing functions, an interface to the SDN controller to receive control decisions and to send measurement on data plane.
[0029] The SDN control-to-data is the interface defined between an SDN controller and a forwarder, which provides at least (i) programmatic control of all forwarding operations, (ii) capabilities advertisement, (iii) statistics reporting, and (iv) event notification. SDN requires a method for the control plane to communicate with the data plane. One such mechanism is the OpenFlow, which is often misunderstood to be equivalent to SDN, but other mechanisms/protocols could also fit into the concept. Therefore, this patent application is not reliant on the OpenFlow protocol.
[0030] SDN controller also has a north-bound interface towards SDN applications and typically provides abstract network views and enable direct expression of network behavior and requirements.
[0031] For the purposes of this invention, a prior art SDN domain is comprised of a controller, and many forwarders controlled by said controller. Illustrated in FIG. 1 is a simple exemplifying network with two SDN domains A and B, where domain A is controlled by controller A 101 and domain B is controlled by controller B 102 .
[0032] The network of SDN A's data plane is comprised of forwarders F 1 , F 2 , F 3 and GF 1 where F 1 , F 2 and F 3 are so called internal forwarders (i.e., has only connectivity to other forwarders within the same domain), while GF 1 is a gateway forwarder (i.e., has at least one connectivity to at least one forwarder in another SDN's domain; SDN B in this specific case). Note that, similarly, SDN B′s data plane is comprised of internal forwarders F 6 , F 7 and F 8 , and gateway forwarders GF 2 and GF 3 , both of which connects to GF 1 of SDN domain A with interconnection links 107 and 108 , respectively. These two links are called inter-SDN links (also known in the public Internet as peering-links), while links such as those between F 1 and F 2 , are called intra-SDN links.
[0033] SDN controller 101 attaches to F 1 , F 2 , F 3 and GF 1 with links labeled 106 a - d with a control-to-data plane interface running a control-to-data plane protocol such as OpenFlow. Similarly, controller 102 attaches to forwarders of SDN Domain B, communicating with a protocol such as OpenFlow. Meanwhile, controllers 101 and 102 are attached to each other with link 103 to exchange control plane information regarding their respective domains.
[0034] Inter-Domain Topology Sharing
[0035] The interconnectivity between SDN controllers of different domains may form a physically separate ‘inter-domain control plane network’ that runs on a separate set of facilities than those of the data plane facilities of SDN domains. Alternatively, said interconnectivity may share the same physical facilities with the inter-domain data plane networks. In this scenario, the inter-domain control plane traffic is put on a path on the inter-domain data network on a so called ‘inter-domain control plane flow’, where the end points of the flow are essentially the two SDN controllers. From the perspective of this invention, these two networking scenarios are indifferent since the same or highly similar system and methods can be applied.
[0036] FIG. 2 shows a prior art SDN network comprised of four different SDN domains, illustrated as clouds G 1 , G 2 , G 3 and G 4 , which are controlled by SDN controllers C 1 , C 2 , C 3 and C 4 , respectively. Note that the links 271 a through 271 e form the ‘inter-domain data plane’ network (or peering network). These links are between the said gateway forwarders of each domain (such as GF 1 , GF 2 and GF 3 of FIG. 1 ). The ‘internal data plane’ connectivity within each domain is not illustrated for the sake of simplicity. Links 371 a, 371 b, 371 d and 371 e form the ‘inter-domain control plane’ network. A close look at the diagram clearly shows that the inter-domain data plane and inter-domain control plane networks may have different network graphs. For example, while C 1 is directly connected to C 2 , C 3 and C 4 , G 1 is only connected to G 2 and G 4 .
[0037] The internal topologies of FIG. 2 's SDN networks are illustrated in FIG. 3 . Note that a distinction is made between an ‘actual’ and ‘a ‘summarized’ internal topology since an SDN domain may share only the graph of summarized internal topology with other SDN controllers.
[0038] The summarized topology definition is fairly broad. It may have, for example, just those links with a specific service-level requirement. This topology is either a subset of the actual network topology, or simply a completely virtual topology of the internal network represented by a grid of links between gateway forwarders of a domain (a star or a mesh, for example). Only the SDN domain controller of each domain can perform the mapping from the summarized topology links to actual topology links of the network.
[0039] Note that the cloud G 1 is the SDN domain 201 , where there are four internal forwarders (hallow circles) and three gateway forwarders (dark circles), 281 a, 281 b and 281 c. Similarly, SDN domain 204 , illustrated as cloud G 4 , has four internal forwarders, and two gateway forwarders labeled as 261 a and 261 b. For example, said link 271 e of FIG. 1 runs between the gateway forwarders 281 b and 291 b. Note that not all the links and forwarders are labeled and explained in detail for the sake of simplicity.
[0040] The future Internet topology according to this invention can be represented as an interconnected set of SDN domains, each domain controlled by a controller (or possibly a federation of controllers which are either mirror image of each other—e.g., primary, secondary configuration, or contain partial distributed control data associated with parts of the SDN domain—e.g., master-slave configuration) and comprised of a topology/graph of interconnected internal and gateway forwarders. Such a network may also dictate a different ‘control plane inter-domain topology’ and ‘data plane inter-domain topology’, as clearly illustrated in FIG. 2 . From the perspective of this invention, different controller distribution mechanisms as stated above within an SDN domain are irrelevant to the invention.
[0041] Note that an SDN controller does not necessarily need to know the actual internal data plane topology of another SDN domain, nor that domain may want to share its internal domain details with other domains. All it needs to know is a data plane topology between the gateway forwarders to determine how to route a flow from a source SDN domain to a destination SDN domain (possibly via other SDN domains) in such a way that certain service level requirements are met. That said, each SDN controller will need to know more about the service capabilities of each SDN domain along the path of the service enabled flow. Such a requirement does not exist for best effort traffic.
[0042] FIG. 4 illustrates an example topology corresponding to the network of FIG. 3 with four SDN domains, as seen by G 1 . SDN domains G 2 , G 3 and G 4 provide a summarized topology of their respective networks to G 1 . It has virtual links between pairs of gateway forwarders (internal to that SDN domain) and associated service-related metrics (aka feature vector), such as
1. High Bandwidth (e.g., 120 Gbps) 2. High Security (e.g., encrypted) 3. High Reliability (e.g., 99.999% reliable) 4. Non-preemptive (e.g., no traffic can bump traffic on this link) 5. Low Packet loss (<0.01%) 6. Low Packet delay and delay variation (by time of day, etc.) 7. Price schedule associated with bandwidth segments (e.g., $2/Km/hour/2 Mbps)
[0050] One or more of the above metrics can be associated with a link. While domain G 4 announces a single service-enabled path, 304 , between 261 a and 261 b, G 2 announces three service-enabled paths, namely, 302 a, 302 b and 302 c to other controllers.
[0051] In an example of G 1 's controller determining for a service-enabled flow path towards G 3 , it has the following service-enabled path options to consider:
1. Flow Path 1 : G 1 -G 2 (via 271 a and 302 b and 271 e )-G 3 2. Flow Path 2 : G 1 -G 2 (via 271 a and 302 c and 302 a and 271 e )-G 3 3. Flow Path 3 : G 1 -G 4 (via 261 a and 304 )-G 3 (via 271 c ) 4. Flow Path 4 : G 1 -G 4 (via 261 a and 304 )-G 3 (via 271 d )
[0056] Of course, there may be other service parameters not defined here, but the general concept is the same. Each of these flow paths has a feature vector of 7 tuples (as defined above) and a different cumulative service grade comprised of its constituent link's properties and may also have a different physical length. Once G 1 makes a determination of which of these flow paths to use for the service-enabled traffic, it has to signal the controllers along the flow path. For example, if G 1 selects Flow Path 4 , then it has to send a so-called resource reservation message to controllers of both G 4 and G 3 to reserve the bandwidth during the life of the flow.
[0057] According to an aspect of this invention, each SDN controller communicates with another SDN controller (over the inter-domain control links) the following:
1. Intra-domain summarized topology update: send/update its domain's summarized topology (periodically or on a per event-basis). This topology may include the peering links attached to said domain; 2. Resource reporting: send/update feature vector associated with each link of the summarized topology (periodically or on a per event-basis. A link, for example, can be a flow path with a specific bandwidth on a set of facility. It may include the feature vector of the peering links attached to said domain; 3. Resource reservation request: request to reserve a specific link(s) and service-level(s); 4. Resource negotiation: negotiate a specific service-level of a flow with another controller; 5. Resource release notification: release a specific link reserved for a flow; 6. Control-plane topology update: send/update its inter-domain control-plane topology. This knowledge enables each SDN controller to construct the actual inter-domain control plane topology between controllers of different domains. Such an update may be required when (i) an SDN controller discovers a new SDN controller come to life; (ii) an SDN controller discovers an existing SDN controller's shut down; a new facility is added between a pair of existing SDN controllers, etc.
[0064] To summarize, according to an aspect of this invention, each SDN controller must have knowledge the following key topologies to make a determination for routing of a service-enabled flow:
1. Intra-domain actual topology: actual connectivity between forwarders (both internal and gateway) of a controller's own SDN domain, and associated service parameters. This is an actual topology, not summarized; 2. Inter-domain peering topology: actual connectivity between it's gateway forwarders and the gateway forwarders of different SDN domains, and associated service parameters; 3. Intra-domain summarized topology: an equivalent topology of each SDN domain communicated by their respective SDN controller to SDN controllers of other domains, and associated service parameters. This communication takes place on the inter-domain control links between SDN controllers. Each SDN controller periodically (or on an event-driven basis) obtains the intra-domain summarized topology from all other SDN domains' controllers as described above. Note that for each feature within the feature vector, the intra-domain summarized topology may yield a different topological layout. 4. Inter-domain control plane topology: Actual connectivity between the SDN controllers of different domains where the signaling communications take place to: (i) share summarized topology information; (ii) reserve a service-enabled flow path; (iii) negotiate service capabilities with other domains' SDN controllers; (iv) release a service-enabled flow path; (v) share inter-domain control-plane related information.
[0069] Once an SDN controller makes a determination of a flow's path across multiple domains, it must start the process of resource reservation to ensure that the determined path is available and reserved for the duration of that flow.
[0070] Resource Reservation
[0071] The most well-known protocol for resource-reservation for QoS enabled paths in the Internet is RSVP protocol. This protocol has not been widely popular in the public Internet due to scalability issues when number of routers increases along the path. However, in the context of this invention, it can be conveniently used since the number of SDN controllers along the path on the inter-domain control network is many orders smaller in number than the routers in the Internet (e.g., 8-10 SDN controllers along the path as opposed to hundreds of routers).
[0072] System Description
[0073] The software system of this invention is most conveniently located either within the SDN controller or as an adjunct capability attached to the SDN controller. It is comprised of several key subcomponents as illustrated in FIG. 5 .
[0074] Although we have described the key functions below, there may be other auxiliary components that complement or augment these key functions that are not described here. The key subcomponents are as follows:
Global Service Topology Information Base (GSTIB)—This is a database, which contains most up to date service-enabled summarized topology information periodically collected from all other SDN controllers. This information is required to construct an inter-domain end-to-end flow path with certain service capabilities. Each database entry can be a link (virtual or real) and all associated service parameters, and possibly other relevant information (such as an aging timer). Updated virtual topology information becomes available through periodic updates or as network events occur. The database entries are updated by each SDN controller in real-time. Active Service-Enabled Flow Information Base (ASEFIB)—This is a database of all active flows that originate, terminate and simply traverse that SDN domain. It contains associated flow-path information, service parameters, timers and other related information. Topology Summarizer—It is essential that each controller advertised to other SDN domain controllers an accurate estimate of service parameters for virtual links between its own border gateways, since the performance of inter-domain routing will depend on these parameters. This module determines a summarized topology of the corresponding domain to share with other domains' SDN controllers. This module uses data contained in the ASEFIB and GSTIB. Topology Communicator—This subsystem periodically communicates with other SDN controllers the summarized topology. Topology Communicator is also where the topology information from other SDN controllers is received and processed. The resultant information is sent to the database. Resource Reservation—This is a subsystem that originates a resource reservation on a path computed by Flow Path Constructor. It generates appropriate messages to send to other SDN controllers along the computed flow path. It also receives resource reservation messages from other SDN controllers. It parses messages, and interprets and replies to such messages. Flow Tracker—This is an application that tracks a live flow to ensure the requested service-level is delivered. It collects appropriate measurements to assess the quality of the link. It can also activate renegotiation of the path for the flow by communicating with the Resource Reservation Module. Flow Path Constructor—This is a subsystem computes best path(s) for a service-enabled flow across multiple SDN domains using optimization algorithms of this invention. The request for a new flow path construction comes from the SDN controller when an application (such as video) starts. This application that terminates at the SDN network may make a specific request for QoS or there may be a provisioned default application type-to-QoS mapping in the Controller that triggers the process of Flow Path construction.
[0082] Each SDN domain controller has a complete control of its own intra-domain routing and cooperates with other domain controllers for inter-domain routing. For inter-domain routing, controller of the source domain: i) initially computes a number of likely paths from A (in its domain) to B (in another domain) based on its current aggregated network map (stitched from intra-domain data network and summarized topology of other domains) and associated service parameters, ii) optionally, sends messages to controllers along the likely routes to request bids (price) for the requested service parameters that vary depending on flow type: for standard flows, best effort routing is requested; for service-enabled flows, there may be different levels of service at different price ranges, iii) compares received bids and calculates the optimum virtual path fixing only the entry and exit border gateways for each domain, and notifies the controllers of each domain along the chosen path, iv) controllers of each domain along the chosen path then decide the actual physical routes to be followed in their respective domains given the entry and exit gateways. The final physical route is a concatenation of these routes.
[0083] The proposed end-to-end flow management across multiple SDN domains is the first complete architecture that enables inter-domain network information collection, route negotiation and dynamic inter-domain path allocation, while maintaining autonomy of each domain to have full control of its own domain routing.
[0084] Given the desired service level and the aggregated network model with costs and service quality variation of virtual links, the controller in the source (or destination) domain will decide for a short list of “best” inter-domain flow paths. Although there may be many ways to tackle the problem, such as using a brute-force approach to choose the best solution, it can be posed as a Constrained Least Cost (CLC) problem and algorithmically solved. The CLC problem is known to be NP-complete, so it can be solved by heuristic and approximation algorithms. A Lagrangian relaxation based aggregated cost (LARAC) algorithm can be used since it finds a good path in a short time. This problem can be easily solved over the aggregated graph (which has the full topology of the ‘self’ SDN domain, and the summarized topology of other domains). It provides a full (global) view of the simplified network with relatively small number of nodes and links. Furthermore, given the Controller of the SDN domain making the flow-path determination has a complete/full view of possible flow paths, it can apply specific constraint mask(s) (such as black listed SDN domains) to eliminate certain flow-paths before applying LARAC.
[0085] LARAC also provides a theoretical lower bound solution, which helps to evaluate quality of the result. It offers flexibility to achieve a tradeoff between optimality of the result and runtime so that it can be run in real-time. By randomly removing some links on previously calculated paths from the network, to most preferred inter-domain path candidates can be estimated.
[0086] There are two possible models for inter-controller service level negotiations. The controller of the source (or destination) domain may send messages to controllers along the path directly or may start a recursive messaging process. In recursive messaging, if controller for domain G 1 wishes to send messages to controllers of domains G 2 , G 3 and G 4 for a desired route G 1 -G 2 -G 3 -G 4 , then controller G 1 sends a message to only controller G 2 . If controller G 2 cannot respond positively, then it sends a negative reply to controller G 1 and no further messages are exchanged. Otherwise, controller G 2 sends a request message to controller G 3 . The messaging process continues until a message reaches the final controller G 4 . If the final controller replies positively, then positive reply messages back track from G 4 to G 3 to G 2 to G 1 ; hence all controllers along the path have reached an agreement. The proposed recursive messaging scheme is efficient in terms of total messages exchanged between controllers to reach an SLA agreement. However, other types of messaging schemes can be implemented.
[0087] We focus on two such functionalities: end-to-end flow routing and end-to-end service provisioning. In the proposed inter-domain flow management model, each domain controller has complete control of its own intra-domain routing and cooperates with other domain controllers for inter-domain routing. For inter-domain routing, controller of the source domain: i) initially computes a number of likely paths from A (in its domain) to B (in another domain) based on its current aggregated global network map, ii) sends messages to controllers along the likely routes to request bids (price) for the requested SLA parameters that vary depending on flow type: for standard flows, best effort routing is requested; for service flows, there are levels ranging from priority queue management to virtual slice reservation, iii) compares received bids (price vs. SLA parameters), calculates the optimum virtual path fixing only the entry and exit border gateways for each domain, and notifies the controllers of each domain along the chosen path, iv) The controllers of each domain along the chosen path then decides for the actual physical routes to be followed in their respective domains given the entry and exit gateways. The final physical route is a concatenation of these routes. The proposed end-to-end flow management across multiple admin domains is the first complete architecture that enables inter-domain network information collection, route negotiation and dynamic inter-domain virtual path allocation, while maintaining autonomy of each domain to have full control of its own domain routing.
[0088] FIG. 6 illustrates an exemplifying flow chart of constructing a database of topology information collected by an SDN controller. In step 701 , SDN controller receives from another SDN controller that controller's summarized network topology information and associated feature vector of each path in the topology. In step 702 , it checks to determine if such information is received from all SDN controllers. If yes, in step 703 the database is updated with the received complete information as well as the most current topology information an SDN controller collects from its own network according to step 704 . In step 706 , the system checks to determine if it is time to refresh the topology. If so, it loops back to step 701 to collect fresh topology information. Even when the refresh timer may not have expired, there may be network events that cause outages or network performance degradation in which case the topology or associated service-levels must be updated. Step 707 checks to determine if there is an event that may drive a topology update. If so, it loops back to step 701 to collect refreshed topology information. Doing so, the topology database and features associated with flow paths are kept as current as possible.
[0089] FIG. 7 illustrates an exemplifying flow-chart showing all steps of constructing a service-enabled flow path and releasing that path once the flow is over. At step 801 , a request for a service-enabled flow arrives at the SDN controller. This service request may arrive through a number of ways. For example, a north-bound API of the SDN controller may be utilized to send such a request in real time. Alternatively, a web-based reservation system can be used for system administrators to enter service-enable flow requests with associated features and start-stop times on a provisioning basis. Alternatively, an application (such as video streaming) may invoke the controller for a QoS enabled flow activation. Other methods (not discussed here) may also invoke step 801 . The Flow Path Constructor 407 accesses the topology database 403 in step 802 , and calculates possible paths in step 803 . Starting from the chosen best flow-path, the system sends resource reservation messages to SDN controllers along the path of the flow in step 804 . If resource reservation does not succeed, the system loops back to the next best path in step 803 until a viable path is found, in which case Active Service Flow database (ASEFIB) 401 is updated with the new active flow information in step 805 . At this stage the flow is active according to step 806 . A refresh timer is simultaneously initiated to monitor the performance of the flow path. Flow Tracker 413 accesses the data network to collect performance indicators of the path in step 811 . If there is a change in the network conditions causing the service-level not to be met, according to step 809 , the system loops back to 802 to reconstruct the flow path. If the traffic flow is over or its timer expires according to step 813 , then system sends ‘resource release message’ to other associated SDN controllers to release the path though Resource Reservation 411 . Once the release is successful, it also updates ASEFIB 401 by deleting the released flow according to step 812 .
[0090] The present invention also discloses a non-transitory computer-readable medium containing instructions that, when executed by a processor in a first controller in a first software defined network (SDN), cause the first controller to: store first domain topology information associated with the first SDN in a first database; transmit a first advertisement message to a second SDN controller in a second SDN domain, the first advertisement message comprising the first domain topology information associated with the first SDN, and receive a second advertisement message from a second SDN domain controller in the second SDN domain, the second advertisement message comprising second domain topology information associated with the second SDN; store the received second domain topology information associated with the second SDN in the first database, and autonomously determine an end-to-end flow path for traversal between the first and second SDN domains based on stored topology information in the first database.
[0091] It is understood that any specific order or hierarchy of steps in the processes disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged, or that all illustrated steps be performed. Some of the steps may be performed simultaneously.
[0092] The various embodiments described above are provided by way of illustration only and should not be construed to limit the scope of the disclosure. Those skilled in the art will readily recognize various modifications and changes that may be made to the principles described herein without following the example embodiments and applications illustrated and described herein, and without departing from the spirit and scope of the disclosure.
[0093] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.
[0094] As noted above, particular embodiments of the subject matter have been described, but other embodiments are within the scope of the following claims. For example, the actions recited in the claims can be performed in a different order and still achieve desirable results. As one example, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous.
CONCLUSION
[0095] A system and method has been shown in the above embodiments for the effective implementation of a method and system for delivering service-enabled flow paths across multiple domains in SDN networks. While various preferred embodiments have been shown and described, it will be understood that there is no intent to limit the invention by such disclosure, but rather, it is intended to cover all modifications falling within the spirit and scope of the invention, as defined in the appended claims.
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Systems and methods are described to dynamically set up and tear down service-enabled flow-paths across multiple SDN domains. An SDN controller of a domain periodically shares with other SDN controllers (of other domains) availability of service-enabled paths (aka, a summarized topology) of its respective network as well as associated service parameters of each path segment using a global nomenclature (aka, a dictionary) with other SDN controllers so as to enable each controller to understand and interpret the shared data in the same manner. Hence, each SDN controller can autonomously construct a complete network graph of available service-enabled paths across many domains. Another feature is the use of summarized (internal) topology of each domain as opposed to just using the peering-link related service information to compute desirable path alternatives.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to Provisional Application Ser. No. 61/040,853 filed on Mar. 31, 2008.
BACKGROUND OF THE INVENTION
Conventionally, removal of surface coverings such as shingles from a roof required intense physical labor with manual implements. Several attempts have been made to automate the process. However, such attempts were heavy and cumbersome machines that are not user friendly. The prior art machines commonly were cumbersome and would exert a backward force on the operator and require the operator to apply a force to hold the prior art machines in position.
The present invention provides an automated surface covering removal machine comprising a handle, housing, lever member, reciprocating cylinder and tooth bar that provides vertical or near vertical movement of the tooth bar relative to the surface covering and fasteners that are to be removed. With such vertical movement, there is no backward force exerted on a user when the tooth bar moves from an upper to a lower position. The automated surface covering removal machine of the present application also is lightweight and, therefore, not cumbersome to a user. The reciprocating cylinder of the automated surface covering removal machine of the present application has variable, proportional, stroke height and a removable tooth bar, along with an adjustable handle with ergonomics. The automated surface covering removal machine of the present application is constructed with a replaceable bottom pan on the housing for easy and economical change of parts due to wear and tear after use.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a perspective view of the automated surface covering removal machine of the present application demonstrating the adjustable handle;
FIG. 2 is a sectional side view of the automated surface covering removal machine of the present application taken along line 2 - 2 of FIG. 1 , with the lever member in a lowered position;
FIG. 3 is a sectional side view of the automated shingle removal machine of the present application showing the lever member in a raised position;
FIG. 4 is a perspective view of the automated surface covering removal machine of the present application in a ready to use position;
FIG. 5 is a side view of the automated surface covering removal machine of the present application with the handle in a first position;
FIG. 6 is a side view of the tooth bar and front portion of the automated surface covering removal machine of the present application with the handle in a second position;
FIG. 7 is a sectional, perspective view of the housing and internal components of the automated surface covering removal machine of the present application; and
FIG. 8 is a sectional perspective view of the housing of the automated surface covering removal machine of the present application, with the lever member in a raised position;
FIG. 9 is a sectional perspective view of the surface covering removal machine of the present application showing the lever member in a raised position;
FIG. 10 is a top view of the housing, lever member and an embodiment of the removable edge means of the present application;
FIG. 11 is a top view of the housing, lever member and another embodiment of the removable edge means of the present application;
FIG. 12 is a perspective schematic view of the cylinder and lever assembly of the present application.
DETAILED DESCRIPTION OF THE INVENTION
The surface covering removal machine 2 comprises a handle 4 , a housing 6 , a lever member 12 , a removable edge means 14 and a reciprocating cylinder 18 . The surface covering removal machine 2 may be used in diverse environments, from outdoor removal of roofing shingles to indoor removal of linoleum or carpeted floors. The detailed description that follows is directed to a shingle removal embodiment, but one of ordinary skill in the art will understand that the illustrated exemplary embodiment will be applicable to other contemplated embodiments that may benefit from the upwardly thrusting movement principles disclosed in this application.
Referring to FIG. 1 , the handle 4 is attached to the housing 6 , and includes a handle grip 8 and a trigger 10 . The handle 4 of the automated surface covering removal machine 2 is adjustable in height to be ergonomic. Mechanical fasteners 36 A, 36 B attach the handle to the housing 6 . The operator selects an appropriate mounting hole (e.g., 37 A, 37 B; see, FIGS. 4-6 ) to insert the mechanical fasteners 36 A, 36 B for adjusting the height of the handle 4 . Alternatively, the handle 4 may be positioned within a slot, giving the operator and infinitely adjustable range of heights from a minimum to a maximum position.
The handle grip 8 is designed to be ergonomic allowing the operator to place his or her hands in a comfortable position. Trigger 10 requires very little effort to activate. Trigger 10 is connected to reciprocating cylinder 18 , pneumatically in one embodiment, electrically or hydraulically in other embodiments, to raise and lower lever member 12 and removable edge means 14 from an upper to a lower position. Conduits or hoses 15 may be used to connect the trigger 10 to the reciprocating cylinder 18 , as further demonstrated in FIG. 2 .
Turning now to FIGS. 7-9 , as mentioned, edge means 14 is removable and is attached to lever member 12 through mechanical fasteners 28 . Mechanical fasteners 28 may be any type of mechanical fastener and preferably allow the user to easily remove the edge means 14 for replacement after wear.
Reciprocating cylinder 18 may be attached to the top portion of the housing 6 . The reciprocating cylinder 18 may be mounted to the housing in different manner as well. As shown in FIGS. 2 , 3 , 8 , 9 and 12 , reciprocating cylinder 18 includes a piston rod 24 attached to a lever member attachment shaft 22 . Lever member attachment shaft 22 connects the reciprocating cylinder 18 to the lever member 12 as shown in FIG. 12 , for one embodiment. Lever member 12 is attached to the housing through pivot shaft 20 . By activating reciprocating cylinder 18 , piston shaft 24 depresses lever member attachment shaft 22 downwardly, in turn, raising the front portion of the lever member 12 and removable edge means 14 upwardly, as demonstrated in a comparison between FIGS. 2 and 3 .
Reciprocating cylinder 18 is, in one embodiment, a pneumatic reciprocating cylinder. In another embodiment, the reciprocating cylinder 18 is an electric reciprocating cylinder. In yet another embodiment, the reciprocating cylinder 18 is a hydraulic reciprocating cylinder. In all respects, the reciprocating cylinder 18 has a variable stroke height. When an operator actuates trigger 10 , the lever member 12 will raise upwardly and remain in the up position until the trigger 10 is released. If the trigger 10 is released before the lever member 12 is completely in the up position, the reciprocating cylinder will release and return the lever member to the down position. This proportional, variable stroke feature allows the operator to raise the edge means 14 only the necessary amount to loosen or remove, for example, shingle nails, resulting in less time required to remove and prepare a roof for new shingles.
The interaction between reciprocating cylinder 18 and lever member 12 permits the edge means 14 to be raised to a maximum height of 4 to 8 inches above the lowered position. This height allows the automated surface covering removal machine 2 to pull, for example, adjacent shingles loose from a greater distance, resulting in faster shingle removal. Moreover, the edge means 14 is raised upwardly and downwardly in a vertical or nearly vertical fashion because of the location of pivot shaft 20 . The benefit of this vertical movement is that no backward force is exerted on the operator when the edge means moves from the upper to the lower position. Accordingly, the design is less fatiguing than prior art designs which exerted backward force on the operator.
Referring to FIGS. 5-9 , housing 6 includes a bottom pan 16 . Bottom pan 16 is readily replaceable due to excessive wear and tear that the bottom pan encounters during use of the automated shingle removal machine 2 . The bottom pan 16 of housing 6 includes at least one embossment 26 on the surface that engages the roof. The at least one embossment 26 is, in one embodiment, located near the front portion of the bottom pan 16 . The at least one embossment 26 reduces the surface area that is in contact with the roof and provides a ramp effect, making it easier to slide the automated shingle removal machine 2 on, around and over surfaces that are not always flush with one another. The bottom pan 26 also includes flange 30 that aids in negotiating uneven surface that have a significant change in height.
Referring now to FIGS. 10 and 11 , the edge means 14 is removable from the lever member 12 to permit different designs of edge means 14 to suit particular roofing conditions. For example, the edge means of FIG. 10 has more widely spaced teeth 32 than the edge means of FIG. 11 . As a further example, the edge means may comprise a multi-tooth edge, a serrated edge, a flat edge, a bladed edge, a chisel edge or other similar edge designs to facilitate surface covering removal.
In one embodiment of the automated surface covering removal machine 2 of the present application, as demonstrated in FIG. 2 , the reciprocating cylinder 18 is a pneumatic cylinder powered by a conventional air compressor. Hoses 15 may be connected through handle grip 8 and run through trigger 10 downwardly into the housing 6 and connect to the pneumatic reciprocating cylinder 18 . Quick exhaust check valves 17 A, 17 B provide the connection between the hosing and the reciprocating cylinder 18 . The quick exhaust valves 17 A, 17 B allow the lever member 12 to be raised and lowered quickly, and also exhaust into the housing 6 to assist in keeping the interior of housing 6 clean from dust and debris. As mentioned, when the trigger 10 is compressed, air will flow into the cylinder extending reciprocating cylinder piston 24 downwardly. However, the pneumatic reciprocating cylinder need not be fully extended before retracting; therefore, allowing for variable stroke lengths, proportional with trigger actuation.
Finally, referring back to FIGS. 1 and 4 , the automated surface covering removal machine 2 may include wheels 34 for aid in transporting the machine 2 . The wheels 34 may be attached to the housing at points 34 A, or at other points, if desired.
It is apparent to those skilled in the art that the present invention as described herein contains several features, and that variations to the embodiments as disclosed herein may be made that embody only some of the features disclosed herein. From the foregoing description, certain terms have been used for brevity, clearness and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. The different configurations described herein may be used alone or in combination with other configurations. Various other combinations and modifications or alternatives may also be apparent to those skilled in the art. Such various alternatives and other embodiments are contemplated as being within the scope of the present disclosure.
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An automated surface covering removal machine having a handle, a housing, a lever member, a reciprocating cylinder and edge means for providing vertical or near vertical movement of the edge means relative to the surface covering to facilitate removal of the surface covering is disclosed. The surface covering may be shingles, carpeting, linoleum, or any other type of surface covering. The automated surface covering removal machine is lightweight and easy to use and does not exert a debilitating backwards force on the user. The reciprocating cylinder allows for a variable stroke height of the tooth bar allowing for more rapid removal of a surface covering.
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This application is a continuation-in-part of U.S. patent application Ser. No. 07/944,741 filed Sep. 14, 1992, which is a continuation of U.S. patent application Ser. No. 07/751,718 filed Aug. 29, 1991, now abandoned.
BACKGROUND OF THE INVENTION
I. Technical Field
This invention relates to bring up zones for paint baking ovens. More particularly, the invention relates to a method and apparatus for distributing infrared radiation within this bring up zone of a camel-back paint baking oven to increase the temperature of components passing therethrough.
II. Discussion
Paint baking ovens are used throughout the manufacturing industry to bake the paint or coating applied to various articles such as automobile components. Such paint baking ovens often have conveyors or similar devices for bringing the component to be baked into the paint baking oven and then carrying the component through the various sections or zones of the paint baking oven. Generally, the first section or zone of a paint baking oven is known as a bring up zone. In a camel back paint baking oven this bring up zone has traditionally been positioned in the "hump" of such an oven, or, as shown in U.S. Pat. No. 5,155,335 to Habaki et al., in the oblique ramp connecting the oven entrance to the hump portion. While the component being baked is contained in this bring up zone, a heat source is activated which brings the component's body temperature to a desired level. It is well known in the industry that providing a relatively even body temperature over the entire component gives rise to a more consistent baking which, in turn, results in a more desirable finish.
Traditionally, dark radiation panels contained within the hump portion of the oven have been used as the heat source within paint baking oven bring up zones to obtain a relatively even temperature over the component body. The purpose of the radiant heat bring-up zone is to "skin" the paint coating prior to subjecting it to convection heating in a subsequent holding zone--i.e. to remove any stickiness at the outermost layer of the coating. By the time the painted object leaves such a bring-up zone, most of any solvents in the coating have been driven off by radiant heat. Although some success has been achieved through the use of dark radiation panels as a means of increasing the component's body temperature, it is difficult to control the amount of heat generated over specific areas of the component through the use of dark radiation panels. For example, if the component to be paint baked is an automobile component, it has been discovered that dark radiation panels are a less effective way of heating certain parts such as the roof, bonnet, side doors, wheel houses and other heavy parts because they contain inaccessible hidden surfaces.
Another drawback in using dark radiation panels within the bring up zone is the excessive amount of time necessary to increase the temperature of larger components to the desired level.
Until recently, none of the art known to the Applicant utilized infrared lamps within the bring up zone of a camel back oven to quickly increase the component's temperature to a desired level. U.S. Pat. No. 5,155,335 which issued Oct. 13, 1992 to Habaki discloses an infrared heater disposed within the oblique portion of the oven adjacent the elevated horizontal heating chamber. A severe drawback in disposing the infrared heat source within the oblique section of the oven is the likelihood of damage to the infrared heating source from exposure to the excessive heat generated by the elevated horizontal heating chamber. Typically, the convection heating which occurs within the elevated horizontal portion of a camel back oven is carried out at extremely high temperatures, much higher than the infrared lamps are capable of withstanding. Although Habaki discusses the use of a infrared heating source within the oblique portion of a camel back oven, there is no teaching, either express or implied of disposing a heating source such as infrared lamps within the lower horizontal portion of a camel-back oven to thereby function as a bring up zone. Further, none of the art presently known to the Applicant utilize any type of heating source within the lower horizontal portion of a camel-back oven.
SUMMARY OF THE INVENTION
Accordingly, the invention provides a paint baking oven having a camel back design, wherein a first bring up zone is located below the adjoining convection air paint baking oven section. The first bring up zone includes a lower substantially horizontal portion positioned below the elevated hump portion of the oven which houses the convection air heating section. The components to be baked enter the paint baking oven on a conveyor and are led through the first bring up zone. The component's body temperature is increased while within the lower substantially horizontal portion of this bring up zone by a heat source to begin the paint baking process. Preferably the heat source is a radiant heat sources, although other sources are contemplated. After the component's body temperature has been increased to the desired level, the conveyor transfers the component into the oblique portion of the oven and on to the elevated convection air drying section of the oven where the component is baked, with the paint coating undergoing a chemical reaction.
Heating means are provided within the lower substantially horizontal portion of the bring up zone which are operative to increase the temperature of the component contained therein. The heating means generally comprise a plurality of centrally directed infrared lamps extending from a frame member which selectively projects radiation onto the component as it passes through the leading end of the bring up zone. One of the key features associated with using infrared lamps is that each lamp can be controlled to emit radiation at a selected efficiency between 0-100%. By controlling the efficiency of each lamp, compensation for differences such as size, shape and the amounts and types of coatings used on the component can be effected.
A feature of the invention is to provide a radiation source which evaporates solvents from inside a paint layer. This internal heating eliminates bubbling and/or pops from occurring in the paint or coating as the component temperature is increased.
A further feature of the invention is the relative ease by which the painted object's surface temperature is evenly regulated over certain irregularly shaped portions thereof, due to the use of individually controlled infrared lamps.
Yet another feature of the present invention is to extend the useful life of the infrared lamps by protecting them from the excessive heat generated within the elevated convection air heating portion of the paint baking oven.
BRIEF DESCRIPTIONS OF THE DRAWINGS
The objects and features of the invention will become apparent from a reading of a detailed description taken in conjunction with the drawings, in which:
FIG. 1 is a cross-sectional side view of a first bring up zone arranged in accordance with the principles of the invention.
FIG. 2 is a lateral-sectional view taken at line 2--2 of FIG. 1 showing the bring up zone incorporating infrared lamps.
FIG. 3 is a cross-sectional side view of a camel-back paint baking oven having exhaust means located between a bring up zone and a convection air holding zone.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIGS. 1, 2 and 3, a paint baking oven 10 includes an outer ceiling 12 and a floor 18 interconnected by two side walls 14 and 16. The paint baking oven 10 is a elongated tunnel having first and second end sections 36 and 37 which are separated approximately at the middle point of the paint baking oven 10 by a parallel hump 60 having a bottom surface or floor 50 located at least 0.5 meters above the ceiling 12 of the two end portions. This height differential of at least 0.5 meters between the first end section and the contiguous raised middle section of the camel-back paint baking oven 10 is essential to the proper operation of the present invention. The height differential is designated as in h FIG. 1.
The articles to be baked move along a conveyor 24 from the sealed entrance end 36 to the sealed exit end 37 throughout the elongated tunnel along a path of travel parallel to the longitudinal axis of the zone or section through which the article is passing. The paint baking oven 10 is used to bake articles which are generally designated by the numeral 22. Although an automobile component has been chosen for demonstrative purposes, it will be understood by those skilled in the art that the present invention may be used for other types of articles in addition to automobile components 22.
The component 22 initially enters the camel-back paint baking oven 10 on a conveyor 24 through an air sealed silhouette located at the entrance end 36 of the paint baking oven 10. Component 22 advances within the paint baking oven 10 upon the conveyor 24 through a first bring up zone 30. This first bring up zone 30 lies within a first substantially horizontal portion located along a first end of the oven. As noted, the camel back oven according to the teachings of the present invention is designed such that the floor 50 of the hump portion 60 is located at least 0.5 meters above the ceiling 12 of the horizontal bring up zone 30, as designated by reference letter h in FIG. 1.
Bring up zone 30 includes a heating system disposed therewithin for increasing the temperature of the component 22 to a desired level. The heating system preferably comprises a combination of short wave infrared lamps 25 and medium wave infrared lamps 26, both of which are contained within reflective lamp housings 27 which assist in directing the infrared radiation waves at the component 22. Each of the lamp housings 27 extend inwardly toward the component 22 as it passes through the bring up zone 30 from a frame member 20. Short wave infrared lamps 25 are generally operational over a range of approximately 0.8-2.0 microns and middle wave lamps 26 are generally operational over a range of approximately 2.0-4.0 microns. Ideally, the infrared lamps are operated in a range of between 1.2 and 2.4 microns.
Located between the infrared lamps 25 and 26 and the component 22 passing through the bring up zone 30 is an air tight quartz glass wall 28 which protects the lamps from dust, solvents and resins which might be present in the paint baking oven 10. Quartz glass wall 28 also assists in isolating the infrared lamps 25 and 26 from the hot air surrounding the painted object in the paint baking oven 10.
The infrared lamps are controlled through time pulsing or TRIAC'S by a computer 40 which make it possible to light specific lamps at specific intensities to accommodate for the variances in the painted surface of the component 22 as it passes through bring up zone 30.
The bring up zone 30 also includes an air inlet system for bringing air into the interior of bring up zone 30. The inlet air flows into the trailing end 34 of the bring up zone 30 as designated by arrows 39 through horseshoe or U-shaped inlets 33 where the air is directed downward towards the entrance end 36 of the bring up zone 30. The inlet air serves to cool the infrared lamps 25 and 26 which are susceptible to overheating. Once the inlet air approaches the entrance end 36 of the bring up zone 30 it is circulated back into the zone 30 by a draft of air designated by arrows 30 introduced by blower 46 by entering the leading end 36 of the bring up zone 30 where it can be used to assist in the paint baking process. The air drawn through filtration system 44 to remove dust and evaporated solvents can then be reintroduced into the oven by blower 46 to provide a synergistic effect with the air entering the leading end of the oven 10.
The height differential h between the floor 50 of the hump portion 60 and the ceiling 12 of the first bring up zone 30 also assists in keeping the infrared lamps cool. As a result of this height differential h the excessively hot convection air contained within the hump portion 60 is precluded from contacting the infrared lamps, thus prolonging the useful life of the infrared lamps. The heating convection air from the hump portion 60 is almost entirely maintained within the hump portion 60 and the top half of the oblique portion of the oven. Any minor amounts of heated air generated by convection heating within the hump portion 60 which may seep into the bottom half of the oblique portion would be dissipated by the air entering at inlets 33.
With further reference to FIGS. 1 and 2, the bring up zone 30 operates in the following manner. Component 22 initially enters the paint baking oven 10 on conveyor 24 through an air sealed silhouette (not shown) located at the entrance end 36 of the paint baking oven 10. Once inside the paint baking oven 10 the component 22 advances along the conveyor 24 at a rate of approximately 10-20 ft./minute along a longitudinal path of travel parallel to the longitudinal axis of the particular bring up zone portion.
The heating requirements for the particular component are programmed into a computer 40 which is used to individually control the intensity and efficiency of the infrared lamps 25 and 26 used to bring the component's temperature to the desired level. The computer 40 is programmed to take into account various factors such as the size, shape and the material make up of the component 22 being heated. The computer program also accounts for the absorption factor of the paint which is applied to the component 22. For example, top coat lines of silver metallic paint have the lowest absorption factor and black solids have the highest absorption factor. The computer 40 is, therefore, programmed to operate the infrared lamps 25 and 26 on high power at 100% efficiency when the component 22 is coated with silver metallic paint and to reduce the power and/or the efficiency of the infrared lamps 25 and 26 through time pulsing or TRIAC'S for component 22 coated with paints possessing a higher absorption factor.
As the components 22 pass through the lower substantially horizontal portion of the bring up zone 30, the infrared lamps 26 are activated by the computer 40, according to the control specifications entered therein, to heat the component 22 to the desired level prior to a more intense baking within the convection air holding zones such as zone 38 of FIG. 3. The radiation emitted by the infrared lamps passes through the quartz wall 28 and is directed upon component 22 until the desired component temperature is attained.
Once the component has passed through the bring up zone, the component advances through the remaining oven sections.
One advantage is using infrared lamps 25 and 26 is that the radiant heat penetrates the outer paint surface and bakes the coating from the inside out, heating the innermost layers progressively outwardly toward the skin dried outermost layer. It should be noted however that heat sources other than infrared lamps or panels are contemplated.
The invention has been described with reference to a detailed description of a preferred embodiment given for the sake of example only. The scope and spirit of the invention are to be determined by the appended claims.
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A first bring up zone of a camel-back oven utilizes a plurality of short and/or medium wave infrared lamps to raise the component temperature up to a desired level. Once within the paint baking oven, the component enters into the bring up zone where a computer activates the requisite number of infrared lamps at the proper intensity to achieve the desired component temperature. While the infrared lamps are activated, inlet air is directed over the lamps to prevent them from overheating. The invention allows for smoother car finishes by preventing bubbling and pops and raises the component temperature more quickly than conventional dark radiation panels.
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BACKGROUND OF THE INVENTION
High energy x-ray tubes are used in medical device applications to provide an x-ray source. The materials in the x-ray tube are subject to high temperatures during the operation of the x-ray tube. The x-rays generated by the x-ray tube are directed out of a window toward a target such as portion of a patient. The x-ray tube is subject to high temperatures when the x-ray tube is generating x-rays and then cools. A heat shield may be secured to a portion of the x-ray tube to shield the window from backscattered electrons.
SUMMARY OF THE INVENTION
A fastening assembly includes a fastener having a head with an underside and an elongated shaft extending therefrom. The fastener constructed of at least one of a refractory metal and a superalloy. A washer includes a body with an upper surface and an opposing lower surface which defines opening portion for receiving the elongated shaft of the fastener therethrough. The upper surface of the washer forms diffusion bonds with the underside of the head of the fastener when the washer and the fastener are held in contact at temperatures in excess of 500° C.
In another embodiment, an assembled structure suitable for use at high temperatures includes at least two bolts. Each bolt includes a head with an underside and an elongated shaft extending from the underside. Each bolt is constructed of at least one of a refractory metal and a superalloy. A washer includes a body with an upper surface and an opposing lower surface defining at least a first aperture and a second aperture respectively receiving the shaft of at least the first bolt and the shaft of the second bolt. The assembled structure also includes a first high temperature material into which the at least two bolts have been threaded and a second high temperature material which has been secured to the first high temperature material by the at least two bolts. The underside of the head of each bolt has mechanically measurably diffusion bonded to the upper surface of the washer.
In yet another embodiment a process for securing a heat shield for the insert window of a high energy X-ray tube to a collector for back scattered electrons includes providing a fastener having a head with a member extending therefrom, the member comprising at least one of a refractory metal and a superalloy. The process also includes providing a washer having a body with an upper surface and an opposing lower surface which defines at least a first opening for receiving the member of the fastener therethrough. The process further includes passing the fastener through the first opening of the washer and securing the member to a threading the fastener into a first member. The process also includes subjecting the assembled structure to a high temperature to cause the fastener to diffusion bond to the washer to a mechanically detectable degree.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of the internal structure of the insert of a high energy X-ray tube with a rotating anode target.
FIG. 2 is a perspective view of a backscatter electron collector with a heat shield bolted to it across the X-ray exit path.
FIG. 3 is a front elevation view of a backscatter electron collector with a heat shield bolted to it.
FIG. 4 is a cross section of a backscatter electron collector with a heat shield bolted to it.
FIG. 5 is a cross section of the portion of a backscatter electron collector where a heat shield has been bolted to it.
FIG. 6 is a front elevation of a heat shield in position to be bolted to a collector.
FIG. 7 is a photomicrograph of a cross section of the joint between the underside of a bolt head and a washer after diffusion bonding.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 , the internal structure 10 of the insert of a high energy X-ray tube has a rotating anode target 40 mounted on a bearing 30 that is supported by a frame 20 . A cathode 100 in a housing 90 supplies electrons which are accelerated by a high electrical potential and strike a focus area on the target 40 causing the generation of X-rays. These X-rays are directed out of a window 60 constructed of a material translucent to X-rays such as beryllium. However, not all of the accelerated electrons are absorbed by the target 40 and a collector 80 is provided to absorb many of these backscattered electrons. Some of these backscattered electrons follow the path of the exiting X-rays and strike the window 60 . This subjects the window 60 to thermal stresses that can reduce the operating life of the insert. The window 60 is sealed to the envelope of the insert to maintain an effective vacuum inside the insert. However, the heating and cooling of the window 60 , as the X-ray tube is cycled through a duty cycle of generating X-rays and then being off until the next exposure is called for, causes the window to expand and contract. This expansion and contraction is not precisely matched to that of the wall of the envelope for various reasons and the mismatch causes stress upon the seal that over time can cause it to fail. The heating of the window 60 is ameliorated by interposing a heat shield 50 in the path of backscattered electrons to absorb some of them that would otherwise strike the window 60 . The heat shield is constructed of a material, such as graphite, beryllium, or titanium, which can absorb these backscattered electrons without unduly interfering with the transmission of X-rays. This material, for instance graphite, may lack the ability to undergo much elastic compression and, in fact, may be subject to crushing upon tightening of the bolts 70 , 72 . Heat shield 50 is constructed of a material that is capable of operating in a high temperature environment such as over 500° C. and has high heat conduction. Heat shield 50 absorbs heat and radiates it out. Heat shield 50 is made with graphite or another material that permits x-rays to be transmitted therethrough minimizing effects on image quality as compared to a heat shield made of metals that deflect and/or absorb x-rays compromising image quality. The heat shield is secured in place by bolts 70 and 72 that are threaded in to the collector 80 . The bolts 70 and 72 and the collector 80 are constructed of a material, such as a molybdenum alloy like TZM (A well known and commonly used alloy of titanium, zirconium and molybdenum), or other refractory metals that are used at operating temperatures in excess of about 500° C. and in a temperature region between 500° C. and 1500° C. Other materials for the bolts that have similar operating characteristics to the refractory metals as noted herein are also contemplated. For example, austenitic nickel-chromium based superalloys or other high temperature superalloys are contemplated as well. Superalloys may include certain nickel alloys. Of course other temperature ranges are also contemplated. In one embodiment the operating temperatures will be excess of about 400° C., and in another embodiment the operating temperatures will be in excess of about 300° C. In a further embodiment the operating temperature will be between 300° C. and 1500° C. and in another embodiment the operating temperature will be between 400° C. and 1500° C. In still another embodiment, the operating temperature range will be between 600° C. and 1200° C. In another embodiment the operating temperature range will include the range of 700° C. and 900° C. All of the temperature notations used herein are in degrees Celsius.
Referring to FIG. 2 , the heat shield 50 has been bolted to an appropriate place on the collector 80 with bolts 70 and 72 . The bolts 70 and 72 have been passed through a common washer 110 that has an aperture for the elongated shaft of each bolt. However other types of washer designs are also contemplated, such as a washer that has a region with a first opening and a second opening, where the openings are connected to one another, separated from one another and/or are completely surrounded by the washer body or only partially surrounded by the washer body. The head of each bolt has been snugged against the washer 110 by threading the bolt into the collector 80 such that the underside of the head is in firm contact with the top surface of the washer 110 . The bottom surface of the washer 110 then abuts the top surface of the heat shield 50 . The bottom surface of the heat shield 50 in turn abuts the collector 80 . The washer 110 is constructed of a material, such as nickel, cobalt or iron or alloys thereof, that provide diffusion bonds to the underside of the heads of the bolts 70 and 72 under appropriate conditions of time and temperature such as temperatures in excess of about 500° C. and times in excess of thirty minutes. Of course other temperature and time combinations that provide diffusion bonds are contemplated. In one embodiment the washer material is different than the bolt material. However, the washer material may be the same as the bolt material if diffusion bonds are created as described herein. In an alternative embodiment an intermediate material may be placed between the washer and the bolt to assist in the creation of a diffusion bond. In yet another embodiment, a material may be provided on the threaded portion of the bolts and/or within the threaded region of the collector to provide a diffusion bond between the threaded region of the bolts and the threaded region of the collector. In one embodiment nickel is the intermediate material applied to the threads of the bolts and/or the collector. Other materials that would provide for diffusion bonds between the bolts and collector are contemplated in this alternative embodiment. The inclusion of diffusion bonds between the bolt threads and the threads of the collector provide for additional torque retention between the bolts and collector and make removing the bolts from the collector more difficult if there is a need to repair the x-ray tube structure that requires removal of the bolts. In another embodiment described herein no diffusion bonds are created between the threaded portion of the bolt and the threaded portion of the collector to make removal of the bolts from the collector easier.
Referring to FIG. 3 , the heat shield 50 is bolted to the collector 80 by bolts 70 and 72 whose elongated shafts pass through apertures in washer 110 that has an area of weakness 112 in the region between the two apertures. When the undersides of the heads of the two bolts 70 and 72 have become bonded to the upper surface of the washer 110 , this allows one of the bolts to be retracted by fracturing the washer 110 through this area of weakness 112 . The area of weakness 110 is shown as the mere elimination of some of the web of the washer 110 but other means of enhancing frangibility such as scoring could also be used. In the absence of this area of weakness 112 , the retraction of either bolt 70 or 72 is only possible if that bolt's diffusion bond with the washer 110 is broken. It is mechanically not possible to rotate a single bolt so as to retract it so long as both bolts are attached to the washer 110 and washer is unfractured. The washer is not free to rotate with the bolt being retracted because the other bolt has been passed through it and is still engaged in the threads of the collector 80 .
Referring to FIG. 4 , the heat shield 50 is held in position across the channel 120 through which X-rays pass after being generated by the collision of accelerated electrons with the rotating anode target 40 shown in FIG. 1 . It is held in position by bolt 70 that is threaded into the collector 80 . Neither the washer 110 nor the other bolt 72 is shown in this view.
Referring to FIG. 5 , the elongated shaft 73 of the bolt 70 passes through an aperture in the washer 110 and through the heat shield 50 . The threads 77 of the bolt 70 engage the threads 82 of the collector 80 . The bolt 70 is tightened by threading its threads 77 into the threads 82 of the collector 80 until the underside 75 of its head 71 come in contact with the top surface 111 of the washer 110 . If the heat shield 50 is constructed of a material, like graphite, that does not undergo much elastic compression, it is difficult to secure the bolt 70 against loosening by tightening it so far as to cause elastic compression on the washer. Heat shield 50 may be formed of other materials that provide similar x-ray transmission, electron absorption and high surface temperature to graphite. In other environments washers are adjacent to rigid materials that resist compression and so tightening of the bolt causes elastic compression forces that press against the head of the bolt and providing resistance to its retraction. The bolts 70 and 72 are subject to being loosened by vibration and thermal stresses such as not seeing precisely the same temperature profile as the portion of the collector into which they are threaded and not experiencing the same expansion and contraction as the heat shield 50 through which they are passed. However, at the service temperatures typically seen by the collector 80 and the bolts 70 and 72 , the typical materials of construction, such as molybdenum or molybdenum alloys, do not appreciably diffusion bond across their respective threads 82 and 77 . To address this situation special steps are taken so that the undersides of the heads of theses bolts, such as the underside 75 of the head 71 of bolt 70 , become diffusion bonded to the upper surface 111 of the washer 110 . In particular, the material of the washer 110 is selected so that it will readily diffusion bond to the underside of the bolt head and temperatures are used in manufacture to cause such diffusion bonding. As is readily apparent from FIG. 2 and FIG. 3 , this means that these bolts can only be loosened by fracture of the washer 110 through its region of weakness 112 or fracture of the diffusion bonds to one of the bolts 70 and 72 . In one embodiment the region of weakness 112 will break before the diffusion bonds break between the bolts and washer.
Referring to FIG. 6 , the washer 110 has a region of weakness 112 between its two apertures 113 for bolts that secure the heat shield 50 to the collector 80 . A substantial amount of the material of the washer has been removed to facilitate its fracture upon the application of a reverse torque to a bolt which has diffusion bonded to the washer 110 .
Referring to FIG. 7 , diffusion bonding has occurred between the top surface 111 of the washer 110 and the underside 75 of the head 71 of a bolt after they were placed adjacent to each other and subjected to 1100° C. for 30 minutes.
Diffusion bonding of the bolts to the washer may be done as an independent operation or as a part of the manufacturing of the overall structure. In either case the bolts are passed through apertures in the same washer and threaded into a first high temperature material in such a way as to secure a second high temperature material to the first. One embodiment is when bolts are threaded into the collector of an X-ray tube constructed of a first high temperature material to secure a heat shield constructed of a second high temperature material to the collector. Typically the bolts pass through the second high temperature material after first passing through the washer and before being threaded into the first high temperature material. The bolts are threaded into the first high temperature material until the undersides of their heads contact the top surface of the washers. Then the bolts and washer are subjected to an elevated temperature for a sufficient time to cause mechanically detectable diffusion bonding between the bolts and the washer, i.e. diffusion bonding which can sustain a measurable mechanical load. The mechanically detectable diffusion can be detected and measured with a torque wrench. A typical bonding process for a nickel washer and molybdenum alloy bolts is about 1100° C. for about 30 minutes. This bonding process may be done as part of the procedure for the manufacture of an X-ray tube. The insert portion of an X-ray tube is built up. As part of this build up a collector is installed which has tapped holes. A heat shield is attached using bolts which pass through a common washer which has a separate through aperture for each bolt. The bolts are passed through the heat shield and into the tapped holes in the collector. The bolts are then drawn at least snug-tight against the washer. The vacuum envelope which is typically the outer boundary of the insert is then completed. Processing of the insert results in the collector being exposed to elevated temperatures, resulting in the diffusion bonding between the washer and bolt. The diffusion bonding provides a structure that is suitable for use in a vacuum environment and will not be the source of outgassing which would contaminate the vacuum. The diffusion bonding provides both adequate torque retention to ensure the bolts remain secured within the structure at the high temperature environment as well as ensuring that the means used to provide a secondary torque retention over the use of the threads do not contaminate the vacuum environment when the structure is at temperatures at or above 500° C. or as otherwise noted above herein. The diffusion bonding of the bolts and washer as described herein does not introduce chemicals into the vacuum environment at operating temperature above 500° C. or as otherwise noted above herein.
The diffusion bonding may be weak enough to allow the removal of the bolts by fracture of these bonds but alternatively the washer may be provided with a region of weakness between adjacent apertures that allows the removal of a bolt by applying a reverse torque to the bolt head which causes a fracture of the of the washer through this region. This alternative provides fairly reproducible control of the force necessary to remove a bolt, particularly if the weakness is provided by eliminating some of the material of the washer.
It may be of value to be able to readily remove bolts that have diffusion bonded to a washer. This facilitates to ability to do rework in the construction of an X-ray tube. If needed rework were to require the removal of the heat shield from the collector the ability to remove its securing bolts by fracturing the retaining washer through its area of weakness would be of value. It would allow one to remove the heat shield with less chance of damage. The bolts as described herein at the operating temperature retain their structural integrity in such a manner that the shape of the bolts are not compromised to the extent that the torque between the bolts and collector is not completely degraded. The bolt material provides for resistance to creep at temperatures over 500° C.; good surface stability; and/or corrosion and oxidation resistance. The materials of the bolts being selected to maintain sufficient pretension of the bolt and collector of a predetermined value.
Although the present disclosure has been described with reference to example embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the claimed subject matter. For example, although different example embodiments may have been described as including one or more features providing one or more benefits, it is contemplated that the described features may be interchanged with one another or alternatively be combined with one another in the described example embodiments or in other alternative embodiments. The term metal or metals as used herein with contemplates and includes alloys of the same metal. In another embodiment washer may include a member extending therefrom that is prohibits rotation of the washer by engaging a feature of a surface of the member that the washer is adjacent to. In this manner, the washer may only be removed by fracturing the washer body and or completely removing the bolt or other fastener from the opening of the washer. Because the technology of the present disclosure is relatively complex, not all changes in the technology are foreseeable. The present disclosure described with reference to the example embodiments and set forth in the following claims is manifestly intended to be as broad as possible. For example, unless specifically otherwise noted, the claims reciting a single particular element also encompass a plurality of such particular elements.
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A fastening assembly includes a fastener having a head with an underside and an elongated shaft extending therefrom. The fastener constructed of at least one of a refractory metal and a superalloy. A washer includes a body with an upper surface and an opposing lower surface which defines opening portion for receiving the elongated shaft of the fastener therethrough. The upper surface of the washer forms diffusion bonds with the underside of the head of the fastener when the washer and the fastener are held in contact at temperatures in excess of 500° C.
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FEDERALLY SPONSORED RESEARCH
The United States Government has rights in this invention pursuant to Department of Energy Contract No. DE-AC04-94AL85000 with Sandia Corporation.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to a co-pending application “Method of Fabricating a Microelectronic Device Package with an Integral Window”, by Kenneth A. Peterson and Robert D. Watson.
BACKGROUND OF THE INVENTION
The present invention relates generally to the field of microelectronics, and more specifically to packaging of microelectronic devices in a package having an integral window.
Many different types of microelectronic devices require a window to provide optical access and protection from the environment. Examples of optically-interactive semiconductor devices include charge-coupled devices (CCD), photo-sensitive cells (photocells), solid-state imaging devices, and UV-light sensitive Erasable Programmable Read-Only Memory (EPROM) chips. All of these devices use microelectronic devices that are sensitive to light over a range of wavelengths, including ultraviolet, infrared, and visible. Other types of semiconductor photonic devices emit light, such as laser diodes and Vertical Cavity Surface-Emitting Laser (VCSELS), which also need to pass light through a protective window.
Microelectromechanical systems (MEMS) and Integrated MEMS (IMEMS) devices (e.g. MEMS devices combined with Integrated Circuit (IC) devices) can also require a window for optical access. Examples of MEMS devices include airbag accelerometers, microengines, microlocks, optical switches, tiltable mirrors, miniature gyroscopes, sensors, and actuators. All of these MEMS devices use active mechanical and/or optical elements. Some examples of active MEMS structures include gears, hinges, levers, slides, tilting mirrors, and optical sensors. These active structures must be free to move or rotate. Optical access through a window is required for MEMS devices that have mirrors and optical elements. Optical access to non-optically active MEMS devices can also be required for inspection, observation, and performance characterization of the moving elements.
Additionally, radiation detectors which detect alpha, beta, and gamma radiation, use “windows” of varying thickness and materials to either transmit, block, or filter these energetic particles. These devices also have a need for windows that transmit or filter radiation to and from the device, while at the same time providing physical and environmental protection.
The word “transparent” is broadly defined herein to include transmission of radiation (e.g. photons and energetic particles) covering a wide range of wavelengths and energies, not just UV, IR, and visible light. Likewise, the word “window” is broadly defined herein to include materials other than optically transparent glass, ceramic, or plastic, such as thin sheets of metal, which can transmit energetic particles (e.g. alpha, beta, gamma, and light or heavy ions).
There is a continuing need in the semiconductor fabrication industry to reduce costs and improve reliability by reducing the number of fabrication steps, while increasing the density of components. One approach is to shrink the size of packaging. Another is to combine as many steps into one by integrating operations. A good example is the use of cofired multilayer ceramic packages. Unfortunately, adding windows to these packages typically increases the complexity and costs.
Hermetically sealed packages are used to satisfy more demanding environmental requirements, such as for military and space applications. The schematic shown in FIG. 1 illustrates a conventional ceramic package for a MEMS device, a CCD chip, or other optically active microelectronic device. The device or chip is die-attached face-up to a ceramic package and then wirebonded to interconnect inside of the package. Metallized circuit traces carry the electrical signal through the ceramic package to electrical leads mounted outside. A glass window is attached as the last step with a frit glass or solder seal. Examples of conventional ceramic packages include Ceramic Dual In-Line Package (CERDIP), EPROM and Ceramic Flatpack designs.
Although stronger, ceramic packages are typically heavier, bulkier, and more expensive to fabricate than plastic molded packages. Problems with using wirebonding include the fragility of very thin wires; wire sweep detachment and breakage during transfer molding; additional space required to accommodate the arched wire shape and toolpath motion of the wirebond toolhead; and the constraint that the window (or cover lid) be attached after the wirebonding step. Also, attachment of the window as the last step can limit the temperature of bonding the window to the package.
FIG. 2 illustrates schematically a conventional molded plastic (e.g. encapsulated) microelectronic package. The chip is attached to a lead frame, and a polymer dam prevents the plastic encapsulant from flowing onto the light-sensitive area of the chip during plastic transfer molding. The window is generally attached with a polymer adhesive. Problems with this approach include the use of fragile wirebonded interconnections; and plastic encapsulation, which does not provide hermetic sealing against moisture intrusion.
Flip-chip mounting of semiconductor chips is a commonly used alternative to wirebonding. In flip-chip mounting the chip is mounted face-down and then reflow soldered using small solder balls or “bumps” to a substrate having a matching pattern of circuit traces (such as a printed wiring board). All of the solder joints are made simultaneously. Excess spreading of the molten solder ball is prevented by the use of specially-designed bonding pads. Flip-chip mounting has been successfully used in fabricating Multi-Chip Modules (MCM's), Chip-on-Board, Silicon-on-Silicon, and Ball Grid Array packaging designs.
Flip-chip mounting has many benefits over traditional wirebonding, including increased packaging density, lower lead inductance, shorter circuit traces, thinner package height, no thin wires to break, and simultaneous mechanical die-attach and electrical circuit interconnection. Another advantage is that the chips are naturally self-aligning due to surface tension when using molten solder balls. It is also possible to replace the metallic solder bumps with bumps, or dollops, of an electrically-conductive polymer or epoxy (e.g. silver-filled epoxy). Flip-chip mounting avoids potential problems associated with ultrasonic bonding techniques that can impart stressful vibrations to a fragile (e.g. released) MEMS structure.
Despite the well-known advantages of flip-chip mounting, this technique has not been widely practiced for packaging of MEMS devices, Integrated MEMS (IMEMS), or CCD chips because attaching the chip face-down to a solid, opaque substrate prevents optical access to the optically-active, light-sensitive surface.
The cost of fabricating ceramic packages can be reduced by using cofired ceramic multilayer packages. Multilayer packages are presently used in many product categories, including leadless chip carriers, pin-grid arrays (PGA's), side-brazed dual-in-line packages (DIP's), flatpacks, and leaded chip carriers. Depending on the application, 5-40 layers of dielectric layers can be used, each having printed signal traces, ground planes, and power planes. Each signal layer can be connected to adjacent layers above and below by conductive vias passing through the dielectric layers.
Electrically conducting metallized traces, thick-film resistors, and solder-filled vias or Z-interconnects are conventionally made by thick-film metallization techniques, including screen-printing. Multiple layers are printed, vias-created, stacked, collated, and registered. The layers are then joined together (e.g. laminated) by a process of burnout, followed by firing at elevated temperatures. Burnout at 350-600 C. first removes the organic binders and plasticizers from the substrate layers and conductor/resistor pastes. After burnout, these parts are fired at much higher temperatures, which sinters and densifies the glass-ceramic substrate to form a dense and rigid insulating structure. Glass-forming constituents in the layers can flow and fill-in voids, corners, etc.
Two different cofired ceramic systems are conventionally used, depending on the choice of materials: high-temperature cofired ceramic (HTCC), and low-temperature cofired ceramic (LTCC). HTCC systems typically use alumina substrates; are printed with molybdenum-manganese or tungsten conducting traces; and are fired at high temperatures, from 1300 C. to 1800 C. LTCC systems use a wide variety of glass-ceramic substrates; are printed with Au, Ag, or Cu metallizations; and are fired at lower temperatures, from 600 C. to 1300 C. After firing, the semiconductor die is attached to the fired HTCC (or LTCC) body; followed by wirebonding. Finally, the package is lidded and sealed by attaching a metallic, ceramic, or glass cover lid with a braze, a frit glass, or a solder seal, depending on the hierarchy of thermal processing and on performance specifications.
Use of cofired multilayer ceramic structures for semiconductor packages advantageously permits a wide choice of geometrical designs and processing conditions, as compared to previous use of bulk ceramic pieces (which typically had to be cut and ground from solid blocks or bars). Ceramic packages with high-temperature seals are generally stronger and have improved hermeticity, compared to plastic encapsulated packages. It is well known to those skilled in the art that damaging moisture can penetrate polymer-based seals over time. Also, metallized conductive traces are more durable than freestanding wire bond segments, especially when the traces are embedded and protected within a layer of insulating material.
In summary, conventional methods and designs for packaging of light-sensitive microelectronic devices attach the window (or cover lid containing a window) after completing the steps of die attachment and wirebonding of the chip or MEMS device to the package. Many processing steps are used, which can expose the fragile MEMS structures to particulate contamination and mechanical damage during packaging.
What is needed is a packaging process that minimizes the number of times that a MEMS device is handled and exposed to temperature cycles and different environments, which can possibly lead to contamination of the device. This can be accomplished by performing as many of the package fabrication steps as possible before mounting the MEMS device. What is needed, then, is a packaging process that attaches the window to the package before mounting the chip to the package. It is also desired that the window be attached to the package body at a high temperature to provide a strong, hermetic bond between the window and the body. What also is needed is a method where the MEMS device faces away from the cover lid, so that contamination is reduced when the cover lid is attached last.
Electrical interconnections from the chip to the package are needed that are stronger and less fragile than conventional wirebonds. What also is needed is a package having a high degree of strength and hermeticity. In some cases, it is also desired to stack back-to-back multiple chips, of different types (e.g. CMOS, MEMS, etc.) inside of a single, windowed-package.
Use of the phrase “MEMS devices” is broadly defined herein to include “IMEMS” devices, unless specifically stated otherwise. The word “plastic” is broadly defined herein to include any type of flowable, dielectric composition, including polymer compounds and spin-on glass-polymer compositions. The phrases “released MEMS structures”, “released MEMS elements”, and “active MEMS elements” and “active MEMS structures” are used interchangeably to refer to a device having freely-movable structural elements, such as gears, pivots, hinges, sliders, tilting mirrors; and also to exposed active elements such as chemical sensors, flexible membranes, and beams with thin-film strain gauges, which are used in accelerometers and pressure sensors.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form part of the specification, illustrate various examples of the present invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 shows a schematic cross-section view of a conventional ceramic microelectronic package, where the window or cover lid is attached last, after the microelectronic device has been joined (face-up) to the base and wirebonded.
FIG. 2 shows a schematic cross-section view of a conventional plastic molded microelectronic package, where the microelectronic device, lead frame, and window are encapsulated in a plastic body by a transfer molding process.
FIG. 3A shows a schematic cross-section view of a first example of a microelectronic package according to the present invention, with the package having an integral window attached to a ceramic body including an first (lower) plate, a second (upper) plate, and an attached cover lid.
FIG. 3B shows a schematic cross-section view of the second example of a microelectronic package according to the present invention, with the package having an integral window cofired with a cofired multilayered assembly of twelve individual layers, and an attached cover lid.
FIG. 4A shows a schematic cross-section view of a third example of a microelectronic package according to the present invention that is similar to the second example of FIG. 3B, but with a cofired window substantially filling up the aperture through the first plate.
FIG. 4B shows a schematic cross-section view of a fourth example of a microelectronic package according to the present invention that is similar to the second example of FIG. 3B, but with a cofired window mounted to a recessed lip located inside of the first plate, recessed from the second surface of the first plate.
FIG. 4C shows a schematic cross-section view of a fifth example of a microelectronic package according to the present invention that is similar to the second example of FIG. 3B, but with a window mounted flush to the bottom surface of the first plate.
FIG. 5 shows a schematic cross-section view of a sixth example of a microelectronic package according to the present invention, with the package having an integral window cofired to a cofired multilayered assembly including an first (bottom) plate, a second (middle) plate, a third (top) plate, and an attached cover lid, for packaging a pair of stacked chips, including a MEMS chip flip-chip mounted to the first plate, and a second chip attached to the backside of the MEMS chip, wirebonded to the second plate.
FIG. 6A shows a schematic cross-section view of a seventh example of a microelectronic package according to the present invention that is similar to the first example of FIG. 3A, but with the cover plate removed, and also having a second package, substantially identical to the first example of FIG. 3A (also without a cover plate), where the second package has been inverted and joined to the first package, thereby forming a substantially symmetric package.
FIG. 6B shows a schematic cross-section view of an eighth example of a microelectronic package according to the present invention that is similar to the first example of FIG. 3A, but with the cover plate removed, and also having a second package, substantially identical to the first example of FIG. 3A (also without a cover plate), where the second package has been stacked above the first package and joined to the first package, thereby forming a stacked, double-package.
FIG. 6C shows a schematic cross-section view of a ninth example of a microelectronic package according to the present invention that is similar to the sixth example of FIG. 5, but with the cover plate removed, and also having a second package, substantially identical to the first example of FIG. 5 (also without a cover plate), where the second package has been inverted and joined to the first package, thereby forming a substantially symmetric package.
FIG. 6D shows a schematic cross-section view of a tenth example of a microelectronic package according to the present invention that is similar to the first example of FIG. 5, but with the cover plate removed, and also having a second package, substantially identical to the first example of FIG. 5 (also without a cover plate), where the second package has been stacked above the first package and joined to the first package, thereby forming a stacked, double-package.
FIG. 7 shows a schematic top view along line 1 — 1 of FIG. 3A of a sixteenth example of a microelectronic package for housing at least one microelectronic device according to the present invention, illustrating examples of the electrically conducting metallized traces located on the upper surface of the first plate, including interconnect bumps, interior bond pads, exterior bond pads, and a conductive via.
FIG. 8 shows a schematic top view of a seventeenth example of a microelectronic package for housing at least one microelectronic device according to the present invention, wherein the package can be a multi-chip module (MCM), including multiple integral windows and multiple microelectronic devices in a two-dimensional array.
FIG. 9 shows a schematic side view of a eighteenth example of a microelectronic package for housing at least one microelectronic device according to the present invention, wherein the window further comprises a lens for optically transforming light passing through the window.
FIG. 10A shows a schematic side view of an example of a microelectronic package for housing a microelectronic device, according to the present invention.
FIG. 10B shows a schematic side view of an example of a microelectronic package for housing a microelectronic device, according to the present invention.
FIG. 10C shows a schematic side view of an example of a microelectronic package for housing a microelectronic device, according to the present invention.
FIG. 11 shows a schematic side view of an example of a microelectronic package for housing a microelectronic device, according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a package for housing at least one microelectronic device, comprising a hollow assembly of stacked, electrically insulating plates and an integral window.
It should be noted that the examples of the present invention shown in the figures are sometimes illustrated with the window facing down, which is the preferred orientation during flip-chip bonding. However, those skilled in the art will understand that the completed package can be oriented for use with the window facing upwards. It should also be noted that all of the figures show only a single microelectronic device, illustrated as a microelectronic device or pair of chips. It is intended that the method and apparatus of the present invention should be understood by those skilled in the art as applying equally to a plurality of chips or devices packaged in a one-dimensional or a two-dimensional array, as in a multi-chip module (MCM), including multiple windowed-compartments, and including having a window on either side of the package.
FIG. 3A shows a schematic cross-section view of a first example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention, comprising a hollow assembly 10 of stacked, electrically insulating plates. The assembly 10 of FIG. 3A has an interior interconnect location 12 disposed on an interior surface of hollow assembly 10 , and an exterior interconnect location 14 disposed on an exterior surface of assembly 10 . Assembly 10 further comprises a first plate 16 . Plate 16 has a first surface 20 , an opposing second surface 18 , and a first aperture 22 through plate 16 . Plate 16 also has an electrically conductive metallized trace 24 disposed on surface 18 , for conducting an electrical signal between interior interconnect location 12 and exterior interconnect location 14 . Plate 16 further comprises a first window 26 bonded to plate 16 , for providing optical access to a microelectronic device 100 that could be disposed within assembly 10 .
In FIG. 3A, assembly 10 further comprises a second plate 30 , which has a third surface 34 , an opposing fourth surface 32 , and a second aperture 36 through plate 30 for providing physical access to insert device 100 into package 8 . Surface 18 of plate 16 is bonded to the surface 34 of plate 30 to form assembly 10 . At least one lateral dimension of aperture 36 is slightly larger than the corresponding lateral dimension of aperture 22 . Aperture 22 is substantially aligned with aperture 36 . The lateral dimensions of aperture 36 are slightly larger than the lateral dimensions of chip or device 100 , so that chip or device 100 can fit inside of aperture 36 .
In FIG. 3A, window 26 is attached flush to plate 16 . The attachment can comprise a first seal 38 . Other mounting arrangements will be disclosed later. The shape of aperture 22 and aperture 36 can be polygonal (e.g. square or rectangular) or circular. Aperture 22 can have a different shape than aperture 36 . The horizontal surfaces of device 100 , plate 16 , plate 18 , and window 26 all can be substantially coplaner. Microelectronic device 100 can comprise a microelectronic device 100 .
In FIG. 3A, microelectronic device 100 can be flip-chip mounted (e.g. flipped facedown, with optically active area 109 of chip or device 100 facing towards window 26 ) to surface 18 of plate 16 . The method of flip-chip mounting is well-known to those skilled in the art. Surface 18 can comprise a bond pad 44 electrically connected to metallized trace 24 at interior interconnect location 12 . Microelectronic device 100 can include interconnect bumps pre-attached to chip or device 100 . Alternatively, surface 18 can comprise an interconnect bump 46 , connected either to metallized trace 24 or to bond pad 44 at interior interconnect location 12 . Interconnect bump 46 can comprise an electrically conductive material (e.g. gold, gold alloy, aluminum, solder, and silver-filled epoxy) for electrically connecting chip or device 100 to metallized trace 24 or bond pad 44 . Alternatively, bump 46 can comprise a non-conducting, adhesive material (e.g. epoxy resin, polyimide, silicone, or urethane) for providing mechanical attachment of chip or device 100 to surface 18 .
In FIG. 3A, package 8 can include a bond pad 28 attached to assembly 10 at exterior interconnect location 14 . Bond pad 28 can be electrically connected to metallized trace 24 . Package 8 can also include an electrical lead 40 attached to assembly 10 at exterior interconnect location 14 . Lead 40 can be electrically connected to metallized trace 24 . Optionally, lead 40 can be attached to bond pad 28 . Assembly 10 can also comprise an electrically conductive via 54 , which can be in electrical communication with metallized trace 24 . Via 54 can be oriented perpendicular to surface 18 , and can be disposed from surface 18 to surface 16 . Via 54 can be made electrically conducting by filling hole 54 with solder or other flowable, electrically conducting material.
In FIG. 3A, assembly 10 can include a cover lid 42 attached to surface 32 of plate 30 . Attachment of cover lid 42 can complete the packaging of semiconductor chip or device 100 inside of a sealed package 8 . Cover lid 42 can include a second window (not shown in FIG. 3 A), for providing optical access through aperture 36 . Optionally, the ambient air inside of sealed package 8 can be substantially removed before attaching cover lid 42 , and replaced with at least one gas other than air. This other gas can include an inert gas (e.g. argon, nitrogen, or helium). Helium can be easily detected by a conventional helium leak detector, thereby providing information on the hermetic quality of the joints and seals in package 8 . The level of humidity can also be adjusted prior to sealing package 8 with cover lid 42 .
In FIG. 3A, plate 16 is attached to plate 18 . This attachment can comprise a second seal 48 disposed in-between surface 18 and surface 34 . Seal 48 can have an annular shape. Likewise, the attachment between cover lid 42 and plate 30 can comprise a third seal 50 . Seal 50 can also have an annular shape. The bonding material used for either seals 38 , 48 or 50 can comprise a hermetic sealant (e.g. a braze alloy, a frit glass compound, a glass-ceramic composite, a glass-polymer compound, a ceramic-polymer compound, or a solder alloy) or an adhesive material (e.g. an epoxy resin, a polyimide adhesive, a silicone adhesive, or a urethane adhesive). Selection of a particular material for seal 38 , 48 or 50 should take into consideration the hierarchy of thermal processing for the entire packaging process. Here, “thermal hierarchy” means that the highest temperature processes (e.g. sintering, joining, etc.) are performed first, followed by progressively lower temperature processes, with the lowest temperature process being performed last in the sequence of fabrication steps.
Window 26 can comprise an optically transparent material (e.g. a borosilicate glass, a quartz glass (i.e. fused silica), a low-iron, a leaded glass, a tempered glass, a low thermal-expansion glass, or a transparent ceramic, such as sapphire). Alternatively, a transparent plastic or polymer-based material can be used (e.g. PMMA). Some plastics are transparent in the UV spectrum. Silicon can be used for windows that are transparent in the IR spectrum. Preferably, the window's coefficient of thermal expansion (CTE) is about equal to the CTE of plate 16 . Alternatively, the mismatch in CTE between window 26 and plate 16 can be chosen avantageously so that window 26 is placed in compression. Window 26 can optionally comprise optical quality properties (e.g. purity, flatness, and smoothness).
Window 26 can comprise means for filtering selected wavelengths of light. Coloring dyes, or other elements, can be added to the glass or plastic formulations to form windows that can filter light, as is well-known to the art. Anti-reflection coatings can be applied to the surface or surfaces of window 26 to reduce reflection and/or increase transmission. Also, surface treatments (e.g. thin-film coatings or controlled surface roughness) can be applied to the periphery of window 26 in order to improve the wettability of molten solders and brazes, and to improve the adhesion of window 26 to plate 16 . The same surface treatments can also be applied to the mating surfaces of other pairs of surfaces to be joined, including plates 16 and 30 , and cover lid 42 . Window 26 can also be made of a metal or metal alloy, for use in packaging of a microelectronic device used for detecting energetic particles.
In FIG. 3A, assembly 10 includes plates comprising an electrically insulating material (e.g. a ceramic, a polymer, a plastic, a glass, a glass-ceramic composite, a glass-polymer composite, a resin material, a fiber-reinforced composite, a glass-coated metal, or a printed wiring board composition) well-known to the art. The ceramic material can comprise alumina, beryllium oxide, silicon nitride, aluminum nitride, titanium nitride, titanium carbide, or silicon carbide. Fabrication of ceramic parts can be performed by processes well-known to the art (e.g. slip casting, machining in the green state, cold-isostatic pressing (CIP) followed by hot-isostatic pressing (HIP) or sintering, and uniaxially hot/cold pressing, or rapid forging). Fabrication of plastic and polymer parts can be performed by processes well-known to the art (e.g. transfer molding, injection molding, and machining of printed wiring board (PWB) sheets).
For severe environments, ceramic packages are generally stronger and more hermetic than plastic encapsulated packages. The preferred construction of a microelectronic package with an integral window can use cofired ceramic multilayers. The multiple, stacked ceramic layers are formed by casting a blend of ceramic and glass powders, organic binders, plasticizers, and solvents into sheets or tapes. The organic components provide strength and flexibility to the green (unfired) sheets during substrate personalization and fabrication. Burnout at a relatively low temperature (e.g. 350-600 C.) removes the organic binders and plasticizers from the substrate layers and conductor/resistor pastes. After burnout, these parts are fired at much higher temperatures, which sinters and densities the glass-ceramic substrate to form a dense, rigid, insulating structure. Glass-forming constituents in the layers can flow and avantageously fill-in voids, corners, etc.
Two different cofired ceramic systems are conventionally used, depending on the choice of materials: high-temperature cofired ceramic (HTCC), and low-temperature cofired ceramic (LTCC). If the ratio of ceramic to glass is high (9/1, or greater), the green substrate layer can only be sintered (e.g. densified) at high firing temperatures (e.g. 1300 to 1800 C.). Consequently, the thick-film pastes (e.g. to form metallized trace 24 ) that are typically cofired with the substrate also have to withstand these high temperatures, such as tungsten, or alloys of molybdenum and manganese. The dielectric consists of glass fillers in a ceramic matrix. This system is referred to as HTCC. Alternatively, the dielectric can be a ceramic-filled glass matrix, which can be sintered at much lower firing temperatures (e.g. 600 C. to 1300 C.). Thick-film metallization can comprise high-conductivity metals, such as gold, silver, copper, silver-palladium, and platinum-gold. This system is referred to as LTCC.
If hermetic packaging is not required, then polymer-based materials can be used. Multilayer printed wiring board (PWB) materials can be used for constructing assembly 10 . In this system, metallized trace 24 is fabricated by using an etched-foil process, well-known to those skilled in the art. Similar to cofired ceramic multilayers, the multiple layers of PWB composition are stacked and laminated under pressure and temperature in a single bonding step (e.g. co-bonded) to form a multilayered assembly 10 .
FIG. 3B shows a schematic cross-section view of a second example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention, comprising a hollow assembly 10 of stacked, electrically insulating plates comprising multiple layers of ceramic tape stacked and laminated under simultaneous pressure and temperature (e.g. cofiring) to form a multi-layered cofired ceramic assembly 10 . Such a construction technique readily accommodates the preferred stepped interior-surface profile, as required to hold window 26 and chip or device 100 , since the individual layers are easily punched-out or cut (e.g. via a laser, water-jet, or mechanical press) into shapes of varying sizes that can be stacked and cofired to form multi-layered cofired ceramic assembly 10 . For example, FIG. 3B shows an arrangement for integrating window 26 into first plate 16 comprising an encased joint geometry 39 (where the edges of window 26 are embedded inside plate 16 ). If a bulk ceramic plate were used, it would be very difficult to manufacture such a reentrant, recessed feature for housing window 26 therein. However, by using a laminated, multilayered construction, this is relatively easy to do.
In FIG. 3B, assembly 10 comprises twelve individual layers of ceramic tape stacked and laminated to form a monolithic, unitized body having an integral window 26 . The part of assembly 10 grouped as plate 16 ′ comprises six individual layers (e.g. sheets) of glass-ceramic tape (e.g. layers 61 , 62 , 63 , 64 , 65 , and 66 ). Likewise, the part of assembly 10 grouped as plate 30 ′ comprises six additional individual layers (e.g. layers 67 , 68 , 69 , 70 , 71 , and 72 ). Each layer can be individually personalized with the appropriate inside and outside dimensions. Metallized trace 24 can be deposited on the upper surface of layer 66 (corresponding to surface 18 of FIG. 3A) prior to stacking of the individual layers. Window 26 can be inserted into the stack of layers after the surrounding layers 61 , 62 , 63 , and 64 have been stacked and registered. The remaining eight layers (e.g. 65 - 72 ) can be stacked and registered after window 26 has been inserted. Then, the entire stack of twelve layers (e.g. 61 - 72 ) can be clamped and fired at the appropriate temperature and pressure for the required time to form a unitized, monolithic body including an integral window 26 .
In FIG. 3B, it is not necessary to join plate 16 ′ to plate 30 ′ with a separate seal 48 because this joint is made simultaneously with all of the other layers during the cofiring or co-bonding process.
Those skilled in the art will understand that other thicknesses for plates 16 ′ and 30 ′ can be formed by laminating a different number of layers of the cofired ceramic multilayered material (or co-bonded PWB material). For example, the third example shown in FIG. 4A of the present invention illustrates an example where plate 16 ′ comprises a fewer number of layers (e.g. two layers: 63 and 64 ). In this case, aperture 22 is substantially filled up by window 26 . In this case, window 26 can be fabricated integrally with plate 16 ′ by casting molten glass, or by molding a liquid polymer, directly into aperture 22 .
In the example shown in FIG. 4A, the size of aperture 22 (and, hence, window 26 ) is much smaller than the size of chip or device 100 . It is not required that the size of window 26 be similar to the size of aperture 22 . Also, the example of FIG. 4A shows that the centerline of aperture 22 does not align with the centerline of aperture 36 , e.g. aperture 22 is offset from aperture 36 . It is not required that aperture 22 be aligned with aperture 36 . However, aperture 22 can be substantially aligned with aperture 36 . Those skilled in the art will understand that more than one small aperture 22 can be included in plate 16 ′, for providing multiple locations for providing optical access to chip or device 100 .
FIG. 4B shows a schematic cross-section view of a fourth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention, that is similar to the second example of FIG. 3B, but with window 26 attached to recessed lip 58 formed inside of plate 16 ′, wherein the lip can be recessed away from second surface 20 of first plate 16 ′. Recessed lip 58 can be easily formed by using a cofired multilayered construction, as described previously. FIG. 4B also illustrates that plates 16 ′ and 30 ′ can extend laterally an unlimited distance beyond the immediate material surrounding apertures 22 and 36 .
Alternatively, the width of plates 16 ′ and 30 ′ can be limited to extending only a short distance beyond the apertures 22 and 36 , as illustrated in FIG. 4 A. In this example, plates 16 ′ and 30 ′ can be considered to be a frame for a package that might be housing a single device or chip.
FIG. 4C shows a schematic cross-section view of a fifth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention that is similar to the second example of FIG. 3B, but with window 26 attached flush to second surface 20 of first plate 16 ′. Window 26 can be attached to plate 16 ′ with seal 38 . Seal 38 can comprise a hermetic sealant material or an adhesive material, as described previously. Alternatively, window 26 can be cofired integrally with plates 16 ′ and 30 ′.
FIG. 5 shows a schematic cross-section view of a sixth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention, that is similar to the first example of FIG. 3A; wherein assembly 10 further comprises a second electrically conductive metallized trace 82 disposed on third surface 34 of plate 30 ; and a third plate 80 bonded to third surface 34 , wherein plate 80 includes a third aperture 84 through plate 80 ; and further wherein at least one lateral dimension of aperture 84 is slightly larger than the corresponding lateral dimension of aperture 36 ; and wherein aperture 84 is substantially aligned with aperture 36 . Assembly 10 can further comprise a second bond pad 86 or second electrical lead 88 attached to metallized trace 82 . Assembly 10 can further comprise a second solder-filled via 90 , vertically disposed inside plate 30 . Those skilled in the art will understand that additional plates having apertures and metallized traces can be stacked on top of previous plates, to construct as many levels as is needed.
FIG. 6A shows a schematic cross-section view of a seventh example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention; further comprising a second package 9 that is substantially identical to the first example of package 8 in FIG. 3A, wherein second package 9 can be inverted and bonded with seal 60 to package 8 to form a sealed, symmetric package capable of housing at least two microelectronic devices. In this example, second package 9 serves the function of cover lid 42 (e.g. to cover and seal package 8 ).
FIG. 6B shows a schematic cross-section view of an eighth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention; further comprising a second package 9 that is substantially identical to the first example of package 8 in FIG. 3A, wherein second package 9 can be stacked and bonded with seal 60 to package 8 to form a stacked double-package capable of housing at least two microelectronic devices.
FIG. 6C shows a schematic cross-section view of a ninth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention; further comprising a second package 9 that is substantially identical to the sixth example of package 8 in FIG. 5, wherein second package 9 can be inverted and bonded with seal 60 to package 8 to form a sealed, symmetric package capable of housing at least four microelectronic devices. In this example, second package 9 serves the function of cover lid 42 (e.g. to cover and seal package 8 ).
FIG. 6D shows a schematic cross-section view of a tenth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention; further comprising a second package 9 that is substantially identical to the sixth example of package 8 in FIG. 5, wherein second package 9 can be stacked and bonded with seal 60 to package 8 to form a stacked double-package capable of housing at least four microelectronic devices.
In an eleventh example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention, that is similar to the first example of FIG. 3A; package 8 further comprises a microelectronic device 100 mounted within assembly 10 . Chip or device 100 can be attached to surface 18 . Chip or device 100 can be flip-chip mounted via interconnect bump 46 to metallized trace 24 . Chip or device 100 can comprise a light-sensitive chip or device (e.g. CCD chip, photocell, laser diode, optical-MEMS, or optical-IMEMS device). Light-sensitive chip or device 100 can be mounted with a light-sensitive side 109 facing towards window 26 . An optional seal 52 can be made between chip or device 100 and first surface 18 of plate 16 , after flip-chip bonding has been performed. Seal 52 can have an annular shape. Seal 52 can provide protection from particulate contamination of the optically active face of chip or device 100 (e.g. active MEMS structures), as well as a second layer of environmental protection in addition to third seal 50 .
In a twelfth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention, that is similar to the sixth example of FIG. 5; package 8 further comprises a pair of microelectronic devices, 100 and 102 , mounted within assembly 10 . Chip or device 100 can be attached to surface 18 . Chip or device 100 can be flip-chip mounted via interconnect bump 46 to metallized trace 24 . Second chip or device or device 102 can be bonded to the backside of chip or device 100 with bond 104 . Methods for bonding chips or devices back-to-back include anodic bonding, gold-silicon eutectic bonding, brazing, soldering, and polymer-adhesive attachment. Assembly 10 can further comprise a wirebonded electrical lead 106 , electrically attached to metallized trace 82 and to chip or device 102 . Chip or device 102 can include a second light-sensitive side 110 mounted face-up, e.g. facing towards cover lid 42 . Although not illustrated, cover lid 42 can be attached to assembly 10 using a recessed lip similar to the recessed lip 58 shown in FIG. 4 B. Cover lid 42 can be made of a transparent material. Cover lid 42 can also comprise a cofired ceramic multilayered material, which includes a cofired integral window.
In a thirteenth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention, that is similar to the sixth example of FIG. 5; package 8 further comprises a pair of microelectronic devices, 100 and 102 , mounted within assembly 10 . Second chip or device 102 can be flip-chip mounted to metallized trace 82 disposed on surface 32 .
In a fourteenth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention, that is similar to the ninth example of FIG. 6A; package 8 further comprises a pair of microelectronic devices, 100 and 102 , mounted within assembly 10 . In this example, cover lid 42 includes a second window 108 for providing optical access to light-sensitive side 110 of chip or device 102 .
Optional exterior electrical connections 112 can easily be made on the exterior surface of assembly 10 , to provide means for conducting electrical signals between chip or device 100 and chip or device 102 , as needed.
In a fifteenth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention, that is similar to the ninth example of FIG. 6C; package 8 further comprises a first pair of chips or devices, joined to each other back-to-back, and mounted to a first package 8 , and a second pair of chips or devices, joined to each other back-to-back, and mounted to a second package 9 , wherein the second package 9 is inverted and bonded to the first package 8 (as in FIG. 6 C). In this example, a combination of flip-chip and wirebonded interconnects can be used for interconnecting the chips or devices to the four different levels of metallized circuit traces. Also, each of the four chips or devices can comprise optically-active elements, including MEMS structures, thereby providing the possibility of passing an optical signal through both apertures by direct transmission, or by conversion of optical signals to electrical, and back to optical via the optically-active chips or devices. This can be accomplished, in part, by using exterior connections in-between the four different levels of traces 24 .
FIG. 7 shows a schematic top view along line 1 — 1 of FIG. 3A of a sixteenth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention. Multiple metallized traces can fan out from a smaller pitch to a larger pitch on the periphery of plate 16 . Seals 48 and 52 can have the shape of an annular ring.
FIG. 8 shows a schematic top view of a seventeenth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention, wherein package 8 can be a multi-chip module (MCM) having a two-dimension array of microelectronic devices. In this example, package 8 includes three compartments having an integral window 26 . These windows can be LTCC or HTCC cofired simultaneously along with the rest of the package. Additional microelectronic devices 116 and microelectronic components 118 (e.g. capacitors, resistors, IC's) can be surface mounted to package 8 by conventional techniques, including flip-chip bonding and wirebonding. Cofired windows 26 and/or cover lids 42 can be placed on either side, or both, of the MCM package 8 . Multiple light-sensitive chips or devices can be mounted inside of the multiple windowed compartments.
FIG. 9 shows a schematic side view of a eighteenth example of a microelectronic package 8 for housing at least one microelectronic device according to the present invention, wherein window 26 further comprises a lens 96 for optically transforming light passing through the window. Lens 96 can be used for focusing or concentrating light onto a smaller, or specified, area on chip or device 100 . Lens 96 can be formed integrally into window 26 , or can be attached separately to the surface of window 26 , as in lens 98 . More than one lens 96 could be integrated with window 26 , with each lens having different optical properties. Alternatively, a divergent lens 96 can be used to spread the light.
Alternatively, the example of FIG. 9 can comprise an array of binary optic lenslets made integral with the window 26 . Binary optics technology is the application of semiconductor manufacturing methods to the fabrication of optics. A lens or lens array is laid out on a computer CAD program and transferred to a photo-mask using an e-beam or other writing process. A series of photo-masks are used, in conjunction with various etch steps, to build up the structures of interest. This fabrication technique can be used to make arrays of lenses with 1 micron features in completely arbitrary patterns. Lenslet arrays are straightforward to make with these methods, and can be extremely high quality with no dead space between elements. The advantage of binary optics is that the optical fabrication is not limited to spheres and simple surfaces. Lenslet arrays can be effectively used to performing optical remapping, such as transforming a round aperture into a square pupil. More details on the utility and methods for fabricating binary optic lenslet arrays can be found in U.S. Pat. No. 5,493,391 to Neal and Michie; as well as U.S. Pat. No. 5,864,381 by Neal and Mansell. Both of these referenced U.S. Patents are commonly assigned to the present assignee, Sandia Corporation of Albuquerque, N. Mex.
The present invention can also comprise an electrically-switched optical modulator attached to the package. Alternatively, electrically-switched optical modulator can replace window 26 , such as a lithium niobate window. In the example of a lithium niobate window, application of voltages around 5-6 V can switch the material from being transparent to being opaque, at a frequency of a few billion times per second. Such an active window can be used as a very fast shutter to control the amount of light being transmitted through window 26 . More details about use of lithium niobate as a light modulation device can be found in U.S. Pat. No. 5,745,282 to Negi.
FIG. 10A shows a schematic side view of an example of a package 8 for housing a microelectronic device 100 , according to the present invention. Package 8 comprises an electrically insulating plate 16 having a first surface 20 , an opposing second surface 18 , and an aperture 22 disposed through the plate; an electrical conductor 24 disposed on second surface 18 ; and an integral window 26 covering aperture 22 . Window 26 is directly bonded to plate 16 without using a separate adhesion layer (e.g., polymer adhesive) disposed in-between window 26 and plate 16 . Plate 16 can comprise a multilayered material, such as low-temperature cofired ceramic (LTCC) multilayer or printed wiring board (PWB) composition. Window 26 is mounted flush with first surface 20 of plate 16 , on a recessed lip. Microelectronic device 100 is flip-chip mounted to conductor 24 . Conductor 24 can comprise a metallized trace or electrical lead.
FIG. 10B shows a schematic side view of an example of a package 8 for housing a microelectronic device 100 , according to the present invention. Package 8 comprises an electrically insulating plate 16 having a first surface 20 , an opposing second surface 18 , and an aperture 22 disposed through the plate; an electrical conductor 24 disposed on second surface 18 ; and an integral window 26 covering aperture 22 . Window 26 is directly bonded to plate 16 without using a separate adhesion layer (e.g., polymer adhesive) disposed in-between window 26 and plate 16 . Plate 16 can comprise a multilayered material, such as low-temperature cofired ceramic (LTCC) multilayer or printed wiring board (PWB) composition. The joint between window 26 and plate 16 comprises an encased joint geometry (as previously defined with reference to FIG. 3 B). Microelectronic device 100 is flip-chip mounted to conductor 24 . Conductor 24 can comprise a metallized trace or electrical lead.
FIG. 10C shows a schematic side view of an example of a package 8 for housing a microelectronic device 100 , according to the present invention. Package 8 comprises an electrically insulating plate 16 having a first surface 20 , an opposing second surface 18 , and an aperture 22 disposed through the plate; an electrical conductor 24 disposed on second surface 18 ; and an integral window 26 covering aperture 22 . Window 26 is directly bonded to plate 16 without using a separate adhesion layer (e.g., polymer adhesive) disposed in-between window 26 and plate 16 . Window 26 is mounted to the first surface 20 of plate 16 . Microelectronic device 100 is flip-chip mounted to conductor 24 . Conductor 24 can comprise a metallized trace or electrical lead.
FIG. 11 shows a schematic side view of an example of a package 8 for housing a microelectronic device 100 , according to the present invention. Package 8 comprises an electrically insulating plate 16 having a first surface 20 , an opposing second surface 18 , and an aperture 22 disposed through the plate; an electrical conductor 24 disposed on the second surface; and an integral window 26 substantially filling up aperture 22 . Window 26 is directly bonded to plate 16 without using a separate adhesion layer (e.g., polymer adhesive) disposed in-between window 26 and plate 16 . Window 26 can be fabricated by casting molten glass, or by molding a liquid polymer, directly into aperture 22 , thereby substantially filling up the space defined by aperture 22 . Microelectronic device 100 is flip-chip mounted to conductor 24 . Conductor 24 can comprise a metallized trace or electrical lead.
|
An apparatus for packaging of microelectronic devices, including an integral window. The microelectronic device can be a semiconductor chip, a CCD chip, a CMOS chip, a VCSEL chip, a laser diode, a MEMS device, or a IMEMS device. The package can include a cofired ceramic frame or body. The package can have an internal stepped structure made of one or more plates, with apertures, which are patterned with metallized conductive circuit traces. The microelectronic device can be flip-chip bonded on the plate to these traces, and oriented so that the light-sensitive side is optically accessible through the window. A cover lid can be attached to the opposite side of the package. The result is a compact, low-profile package, having an integral window that can be hermetically-sealed. The package body can be formed by low-temperature cofired ceramic (LTCC) or high-temperature cofired ceramic (HTCC) multilayer processes with the window being simultaneously joined (e.g. cofired) to the package body during LTCC or HTCC processing. Multiple chips can be located within a single package. The cover lid can include a window. The apparatus is particularly suited for packaging of MEMS devices, since the number of handling steps is greatly reduced, thereby reducing the potential for contamination.
| 7
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of U.S. patent application Ser. No. 12/819,602 entitled “Method and System for LIDAR Utilizing Quantum Properties,” filed Jun. 21, 2010 (ARL 09-35) which in turn claim priority of application Ser. No. 12/330,401 (U.S. Pat. No. 7,812,303; ARL07-33) entitled “Method and System for Creating an Image Using Quantum Properties of Light Based Upon Spatial Information From a Second Light Beam Which Does not Illuminate the Subject,” filed Dec. 8, 2008, which claims priority to U.S. Provisional Patent Application Ser. No. 60/993,792 filed Dec. 6, 2007. This application claims priority to U.S. patent application Ser. No. 12/837,668 (ARL 07-33D) entitled “Method and System for Creating an Image Using The Quantum Properties of Sound or Quantum Particles,” filed Jul. 16, 2010, which is a divisional application of U.S. Pat. No. 7,812,303, all of which are incorporated by reference herein. The present application and U.S. patent application Ser. No. 12/819,602 also claim priority of U.S. patent application Ser. No. 12/343,384 filed Dec. 23, 2008, entitled “Method and System for Quantum Imaging Using Entangled Photons Pairs,” now U.S. Pat. No. 7,847,234, issued Dec. 7, 2010 (ALR 09-15), and U.S. patent application Ser. No. 10/900,351, filed on Jul. 28, 2004, now U.S. Pat. No. 7,536,012 (ALR 03-92), which in turn claims priority to U.S. Provisional Application No. 60/493,107, filed Aug. 6, 2003, all of which are incorporated herein by reference.
GOVERNMENT INTEREST
[0002] The invention described herein may be manufactured, used, and/or licensed by or for the United States Government.
BACKGROUND OF THE INVENTION
[0003] One surprising consequence of quantum mechanics is the nonlocal correlation of a multi-particle system measured by joint-detection of distant particle detectors. In two publications by R. Meyers, K. S. Deacon, Y. H. Shih, entitled “Ghost Imaging Experiment by Measuring Reflected Photons,” Phys. Rev. A, Rapid Comm., Vol. 77, 041801 (R) (2008) and “A new Two-photon Ghost Imaging Experiment with Distortion Study,” J. Mod. Opt., 54: 16, 2381-2392 (2007), both of which are hereby incorporated by reference, “ghost imaging” of remote objects by measuring reflected photons is reported.
[0004] “Ghost imaging” is a technique that allows a camera or image capture device to produce an image of an object which the camera or device does not directly receive; hence the terminology “ghost.” Early demonstrations of ghost imaging were based on the quantum nature of light; using quantum correlations between photon pairs to build an image of the unseen object. Generally speaking, “ghost imaging” comprises the characteristics of nonlocal multiphoton interference and imaging resolution that differs from that of classical imaging. Using correlated photons from photon pairs, a camera constructs an image using recorded pixels from photons that hit simultaneously at the object and the camera's image plane.
[0005] Two types of “ghost imaging” has been used experimentally since 1995; Type I uses entangled photon pairs as the light source and Type II uses a chaotic thermal light. Klyshko diagrams are shown for Type I and II sources are shown in FIGS. 2 and 3 respectfully.
[0006] Conventional line-of-sight imaging (graphically depicted in FIG. 1 ) lacks the ability to image target objects hidden by obstacles such as terrain, vegetation, buildings, and caves that place limitations on sensor positioning and field of view. Experiments have been performed proving that Ghost Imaging has abilities beyond those of classical imaging; including imaging through obscurants and turbulence.
[0007] FIG. 4 is a schematic diagram of an experimental optical device by Pittman, et al., as described in Pittman, et al. “Optical Imaging by Means of Two-photon Quantum Entanglement: Physical Review A, Vol. 52, No. 5, November 1995, hereby incorporated by reference, and hereinafter referred to as Pittman, et al. As described in Pittman, et al., signal and idler beams emerging from the SPDC crystal are sent in different directions so that coincidence detections may be performed between two distant photon counting detectors. An aperture placed in front of one of the detectors, for example, the letters UMBC, is illuminated by the signal beam through a convex lens. By placing the other detector at a distance prescribed by a “two-photon Gaussian thin lens equation” and scanning it in the transverse plane of the idler beam, a sharp magnified image of this aperture is observed in the coincidence counting rate, even though both detector's single counting rates remain constant.
[0008] The Pittman, et al. experimental setup is shown in FIG. 4 . In the experiment a 2-mm-diameter beam from the 351.1-nm line of an argon ion laser is used to pump a nonlinear beta barium borate (BBO) (β-BaB 2 0 4 ) crystal that is cut at a degenerate type-II phase-matching angle to produce pairs of orthogonally polarized signal (e-ray plane of the BBO) and idler (o-ray plane of the BBO) photons. The pairs emerge from the crystal nearly collinearly, with ω s =ω i =ω p/2 . The pump is then separated from the slowly expanding down-conversion beam by a UV grade fused silica dispersion prism and the remaining signal and idler beams are sent in different directions by a polarization beam-splitting Thompson prism. The reflected signal beam passes through a convex lens with a 400-mm focal length and illuminates the (UMBC) aperture. Behind the aperture is the detector package D 1 , which consists of a 25-mm focal length collection lens in whose focal spot is a 0.8-mm-diam dry ice cooled avalanche photodiode. The transmitted idler beam is met by detector package D 2 , which consists of a 0.5-mm-diameter multimode fiber whose output is mated with another dry ice cooled avalanche photodiode. Both detectors are preceded by 83-nm-bandwidth spectral filters centered at the degenerate wavelength 702.2 nm. The input tip of the fiber is scanned in the transverse plane by two orthogonal encoder drivers, and the output pulses of each detector, which are operating in the Geiger mode, are sent to a coincidence counting circuit with a 1.8-ns acceptance window. By recording the coincident counts as a function of the fiber tip's transverse plane coordinate, an image of the UMBC aperture is seen as described further in Pittman, et al. The aperture containing the UMBC that was inserted in the signal beam (about 3.5×7 mm) is shown in the upper right, and the observed image (reportedly measured 7×14 mm) is shown beneath the aperture. Pittman, et al. demonstrated the viability of ghost imaging, it did not provide a viable solution for non-line-of-sight imaging, Current Ghost Imaging methods are based on having the object being imaged in the line-of-sight or field of view of the bucket detector.
SUMMARY OF PRESENT INVENTION
[0009] The present invention is directed to obtaining an image of an object that is not in the direct line of sight or field of view of the viewer, which may be for example, a bucket detector. When a photon detector is aimed nearby the object but not at the object then a Ghost Image of part or the entirety of the object is generated. The photon detector detects photons from a first area which have been scattered by a process such as multiple scattering into a second area such that the detector measures photons while aimed at the second area. In addition, photons from the target area may scatter and induce fluorescence in the second area such that a ghost image can also be formed from the fluorescent photons.
[0010] A preferred embodiment of the present invention enables imaging of an object or subject area when without the object or subject area being in the field of view of the bucket detector. This creates the possibility of imaging around corners; imaging of concealed objects, imaging of objects not in the line-of-sight to the detector, remote sensing, microscopic sensing, spectroscopy, identification of hidden or concealed objects, remote biometrics, design of new sensors and image processing methods, design of new types of stealth technology, design of new types of communications devices.
[0011] The present invention demonstrates the ability to obtain an image of an object using a detector that is not in the direct line of sight or field of view of the image. By aiming a detector at a point nearby the object but not at the object then an image of part or the entirety of the object is generated. Thus, an image of object may be generated even in the presence of turbulence which might otherwise be disruptive to image generation or when a direct view of the object is not possible.
[0012] Scattering of quantum particles such as photons off an object carries information of the object shape even when the quantum particles such as photons of light do not go directly to the receiver/detector, but may in turn be rescattered. The receiver/detector picks up quantum information on the object shape and its temporal relations to separately reference fields. The reference fields are recorded by an imager (CCD, digital cameras, video cameras, scanner, or camera, etc.) that looks at the light source but not the object. This technique may be utilized even when the detector was aimed at a region to the side of the object that was coplanar with the object. Experiments performed determined that Ghost Imaging has abilities beyond those of classical imaging, including imaging through obscurants and turbulence. Experiments have confirmed the potential to generate ghost images of objects when the “bucket” detector used in ghost imaging is significantly occluded.
[0013] A preferred method comprises obtaining an image of an object out of line of sight comprising directing a chaotic light beam at a first area containing the object; measuring the light from the chaotic light beam at a plurality of instances in time; using a photon detector, detecting light from a second area over a plurality of instances in time; the photon detector not being in the line of sight with the first area but in line-of-sight with a second area; using a processor, correlating the information received by the photon detector with the measurement of light from the chaotic light beam at specific instances in time; and producing an image of the object.
[0014] A preferred embodiment comprises a system for imaging information comprising a spatial receiver, a chaotic photon light source for producing light; the light comprising a first beam adapted to be directed at a first predetermined area containing an object, and a second beam which is received by the spatial receiver and measured at specific intervals in time; at least one processor operatively connected to the spatial receiver, the spatial receiver operating to transmit spatial information correlated to specific intervals of time to the processor; a first receiver operatively connected to the at least one processor and operative to detect the influence of the object on the first portion of the light beam; the first receiver not being in the line of sight with the first predetermined area and adapted to detect light from a second predetermined area spaced from and coplanar with the first predetermined area, and the at least one processor operating to correlate the outputs of the first receiver with spatial information derived from the spatial receiver at correlating intervals of time to create an image of the object.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The present invention can best be understood when reading the following specification with reference to the accompanying drawings, which are incorporated in and form a part of the specification, illustrate alternate embodiments of the present invention, and together with the description, serve to explain the principles of the invention. In the drawings:
[0016] FIG. 1 is a graphical illustration of “Classical Imaging.”
[0017] FIG. 2 is a Klyshko diagram for Type-I Ghost Imaging.
[0018] FIG. 3 is a Klyshko diagram for Type-II Ghost Imaging.
[0019] FIG. 4 is a schematic diagram of an optical device by Pittman, et al., as described in “Optical Imaging by Means of Two-photon Quantum Entanglement: Physical Review A, Vol. 52, No. 5, November 1995.
[0020] FIG. 5A is a schematic illustration of a quantum ghost imaging system comprising an arbitrary random, spatially correlated light source 12 in an air medium as the source of the illuminating light.
[0021] FIG. 5B is an illustration of the actual ghost image display on a monitor using the system of FIG. 5A .
[0022] FIGS. 6A through 6F are a set of images depicting the results of a reflection ghost imaging experiment wherein the light path to the bucket detector passes through an obscuring medium. In this example the location of the obscuring medium is in the vicinity of position 15 of FIG. 5A .
[0023] FIG. 6A is an instantaneous image of the spatially varying intensity of light source 12 collected on the detector 22 (using the target ARL) of FIG. 5A .
[0024] FIG. 6B is an averaged image of the light source 12 obtained from detector 22 on averaging of 100 such images according to FIG. 6A .
[0025] FIG. 6C is a G (2) image of the object obtained by correlation to photon ghost imaging from signals 17 and 23 of FIG. 5A .
[0026] FIG. 6D is an instantaneous image of the light source; object reflection.
[0027] FIG. 6E is an averaged image of the source.
[0028] FIG. 6F is the G (2) image of object reflection.
[0029] FIG. 7 is an illustrative schematic indicating that a quantum ghost image can be generated if there are phase aberrations in a path, using either transmitted or reflected photons.
[0030] FIG. 8 is a perspective schematic view of quantum ghost imaging according to FIG. 7 with a partially transparent mask encoding the letters “ARL.”
[0031] FIG. 9 is a perspective schematic view of quantum ghost imaging generated with a correlated photons of a light emitting diode (LED) incoherent light source.
[0032] FIG. 10 is schematic depiction of an experimental set-up for quantum imaging “absent-line-of-sight.”
[0033] FIG. 11 is an illustration of an “ARL” target of FIG. 10 printed in white and illustrating the approximate location 31 where the bucket detector 16 was aimed.
[0034] FIG. 12 is an illustration of a ghost image computed using only the per frame photon counts integrated insider of the white box 31 (shown in FIGS. 10 and 11 ) using 10,000 frames and the G (2) ghost image was computed using compressive imaging methods.
[0035] FIG. 13 is an illustration of result of ensemble integration of all the reference field measurements for 10,000 frames.
[0036] A more complete appreciation of the invention will be readily obtained by reference to the following Description of the Preferred Embodiments and the accompanying drawings in which like numerals in different figures represent the same structures or elements. The representations in each of the figures are diagrammatic and no attempt is made to indicate actual scales or precise ratios. Proportional relationships are shown as approximates.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. However, this invention should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions may be exaggerated for clarity. Like numbers refer to like elements throughout. As used herein the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0038] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0039] It will also be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.
[0040] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. For example, when referring first and second locations, these terms are only used to distinguish one location, element, component, region, layer or section from another location, elements, component, region, layer or section. Thus, a first location, element, component, region, layer or section discussed below could be termed a second location, element, component, region, layer or section without departing from the teachings of the present invention.
[0041] As used herein the terminology target path, object path, target beam, or object beam refers to the beam or path directed to the target or object space and or area. The terminology reference path or beam relates to the photon path or beam which is detected and/or measured by the CCD, camera, etc. (e.g. element 22 ). The terminology is not intended to limit the scope of the invention inasmuch as other terminology could be used to similarly describe similar operating systems.
[0042] Embodiments of the present invention are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments of the present invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the present invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. The regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region of a device and are not intended to limit the scope of the present invention.
[0043] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0044] A ghost image is the result of a convolution between the aperture function (amplitude distribution function) of the object A({right arrow over (ρ)} o ) and a δ-function like second-order correlation function G (2) ({right arrow over (ρ)} o ,{right arrow over (ρ)} i )
[0000] F ({right arrow over (ρ)} i )=∫ obj d{right arrow over (ρ)} o A ({right arrow over (ρ)} o ) G (2) ({right arrow over (ρ)} o ,{right arrow over (ρ)} i ). (1)
[0000] where G (2) ({right arrow over (ρ)} o ,{right arrow over (ρ)} i )≅δ({right arrow over (ρ)} o − −{right arrow over (ρ)} i /m), {right arrow over (ρ)} o and {right arrow over (ρ)} i are 2D vectors of the transverse coordinate in the object plane and the image plane, respectively, and m is the magnification factor. The term δ function as used herein relates to the Dirac delta function which is a mathematical construct representing an infinitely sharp peak bounding unit area expressed as δ(x), that has the value zero everywhere except at x=0 where its value is infinitely large in such a way that its total integral is 1. The δ function characterizes the perfect point-to-point relationship between the object plane and the image plane. If the image comes with a constant background, as in this experiment, the second-order correlation function G (2) ({right arrow over (ρ)} o ,{right arrow over (ρ)} i ) in Eq. (1) must be composed of two parts
[0000] G (2) ({right arrow over (ρ)} o ,{right arrow over (ρ)} i )= G 0 +δ({right arrow over (ρ)} o −{right arrow over (ρ)} i /m ). (2)
[0000] where G 0 is a constant. The value of G 0 determines the visibility of the image. One may immediately connect Eq. (2) with the G (2) function of thermal radiation
[0000] G (2) =G 11 (1) G 22 (1) +|G 12 (1) | 2 . (3)
[0000] where G 11 (1) G 22 (1) ˜G o is a constant, and |G 12 (1) | 2 ˜δ({right arrow over (ρ)} 1 −{right arrow over (ρ)} 2 ) represents a nonlocal position-to-position correlation. Although the second-order correlation function G (2) is formally written in terms of G (1) s as shown in equation (3), the physics are completely different. As we know, G 12 (1) is usually measured by one photodetector representing the first-order coherence of the field, i.e., the ability of observing first-order interference. Here, in Eq. (3), G 12 (1) is measured by two independent photodetectors at distant space-time points and represents a nonlocal EPR correlation.
[0045] Differing from the phenomenological classical theory of intensity-intensity correlation, the quantum theory of joint photodetection, known conventionally as Glauber's theory and published in Glauber, R. J., “The Quantum Theory of Optical Coherence,” Phys. Rev. 130, 2529-2539 (1963) (hereby incorporated by reference); and Glauber, R. J. “Coherent and Incoherent States of the Radiation Field,” Phys. Rev. 131, 2766 (1963) (hereby incorporated by reference) dips into the physical origin of the phenomenon. The theory gives the probability of a specified joint photodetection event
[0000] G (2) =Tr[{circumflex over (ρ)}E (−) ({right arrow over (ρ)} 1 ) E (−) ({right arrow over (ρ)} 2 ) E (+) ({right arrow over (ρ)} 2 ) E (+) ({right arrow over (ρ)} 1 )] (4)
[0000] and leaves room for us to identify the superposed probability amplitudes. In Eq. (4), E (−) and E (+) are the negative and positive-frequency field operators at space-time coordinates of the photodetection event and {circumflex over (ρ)} represents the density operator describing the radiation. In Eq. (4), we have simplified the calculation to 2D.
[0046] In the photon counting regime, it is reasonable to model the thermal light in terms of single photon states for joint detection,
[0000]
ρ
^
≃
0
〉
〈
0
+
ε
4
∑
κ
→
∑
κ
→
′
a
^
†
(
κ
→
)
a
^
†
(
κ
→
′
)
0
〉
〈
0
a
^
(
κ
→
′
)
a
^
(
κ
→
)
,
(
5
)
[0000] where |ε|<<1. Basically, one models the state of thermal radiation, which results in a joint-detection event, as a statistical mixture of two photons with equal probability of having any transverse momentum {right arrow over (κ)} and {right arrow over (κ)}′.
[0047] Assuming a large number of atoms that are ready for two-level atomic transition. At most times, the atoms are in their ground state. There is, however, a small chance for each atom to be excited to a higher energy level and later release a photon during an atomic transition from the higher energy level E 2 (ΔE 2 ≠0) back to the ground state E 1 . It is reasonable to assume that each atomic transition excites the field into the following state:
[0000]
Ψ
〉
≃
0
〉
+
ε
∑
k
,
s
f
(
k
,
s
)
a
^
k
,
s
†
0
〉
,
[0000] where |ε|<<1 is the probability amplitude for the atomic transition. Within the atomic transition, f(k, s)= ψ k,s |ψ is the probability amplitude for the radiation field to be in the single-photon state of wave number k and polarization s:|ψ k,s † =|1 k,s ={circumflex over (α)} k,s |0>.
[0048] For this simplified two-level system, the density matrix that characterizes the state of the radiation field excited by a large number of possible atomic transitions is thus
[0000]
ρ
^
=
∏
t
0
j
{
0
〉
+
ε
∑
k
,
s
f
(
k
,
s
)
-
ω
t
0
j
a
^
k
,
s
†
0
〉
}
×
∏
t
0
k
{
〈
0
+
ε
*
∑
k
′
,
s
′
f
(
k
′
,
s
′
)
ω
′
t
0
k
〈
0
a
^
k
′
,
s
′
}
≃
{
0
〉
+
ε
[
∑
t
0
j
∑
k
,
s
f
(
k
,
s
)
-
ω
t
0
j
a
^
k
,
s
†
0
〉
]
+
ε
2
[
…
]
}
+
ε
*
2
[
…
]
}
.
×
{
0
〉
+
ε
*
⌈
∑
t
0
k
∑
k
′
,
s
′
f
(
k
′
,
s
′
)
ω
t
0
k
〈
0
a
^
k
′
,
s
′
⌉
[0000] where e −iωt 0j is a random phase factor associated with the state |ψ of the jth atomic transition. Summing over t 0j and t 0k by taking all possible values, we find the approximation to the fourth order of |ε|,
[0000]
ρ
^
≃
0
〉
〈
0
+
ε
2
∑
k
,
s
f
(
k
,
s
)
2
l
k
,
s
〉
〈
l
k
,
s
+
ε
4
∑
k
,
s
∑
k
′
,
s
′
f
(
k
,
s
)
2
f
(
k
′
,
s
′
)
2
l
k
,
s
l
k
′
,
s
′
〉
〈
l
k
,
s
l
k
′
,
s
′
.
[0000] The second-order transverse spatial correlation function is thus
[0000]
G
(
2
)
(
ρ
→
1
,
ρ
→
2
)
=
∑
κ
→
,
κ
→
′
〈
0
E
2
(
+
)
(
ρ
→
2
)
E
1
(
+
)
(
ρ
→
1
)
l
κ
→
l
κ
→
′
〉
2
.
(
6
)
[0049] The electric field operator, in terms of the transverse mode and coordinates, can be written as follows:
[0000]
E
j
(
+
)
(
ρ
→
j
)
∝
∑
κ
→
g
j
(
κ
→
;
ρ
→
j
)
a
^
(
κ
→
)
,
(
7
)
[0000] where â{right arrow over (κ)} is the annihilation operator for the mode corresponding to {right arrow over (κ)} and g j ({right arrow over (ρ)} j ; {right arrow over (κ)}) is the Green's function associated with the propagation of the field from the source to the jth detector. Substituting the field operators into Eq. (6), we obtain
[0000]
G
(
2
)
(
ρ
→
1
,
ρ
→
2
)
=
∑
κ
→
,
κ
→
′
g
2
(
κ
→
;
ρ
→
2
)
g
1
(
κ
→
′
;
ρ
→
1
)
+
g
2
(
κ
→
′
;
ρ
→
2
)
g
1
(
κ
→
;
ρ
→
1
)
2
.
(
8
)
[0000] Eq. (8) indicates a two-photon superposition. The superposition happens between two different yet indistinguishable Feynman alternatives that lead to a joint photodetection: (1) photon {right arrow over (κ)} and photon {right arrow over (κ)}′ are annihilated at {right arrow over (ρ)} 2 and {right arrow over (ρ)} 1 , respectively, and (2) photon {right arrow over (κ)}′ and photon {right arrow over (κ)} are annihilated at {right arrow over (ρ)} 2 and {right arrow over (ρ)} 1 , respectively. The interference phenomenon is not, as in classical optics, due to the superposition of electromagnetic fields at a local point of space time. It is due to the superposition of g 2 ({right arrow over (κ)}; {right arrow over (ρ)} 2 )g 1 ({right arrow over (κ)}′; {right arrow over (ρ)} 1 ) and g 2 ({right arrow over (κ)}′; {right arrow over (ρ)} 2 )g 1 ({right arrow over (κ)}; {right arrow over (ρ)} 1 ) the so-called two-photon amplitudes.
[0050] Completing the normal square of Eq. (8), it is easy to find that the sum of the normal square terms corresponding to the constant of G 0 in Eq. (2): Σ {right arrow over (κ)} |g 1 ({right arrow over (κ)}; {right arrow over (ρ)} 1 )| 2 Σ {right arrow over (κ)}′ |g 2 ({right arrow over (κ)}′; {right arrow over (ρ)} 2 )| 2 =G 11 (1) G 22 (1) , and the cross term |Σ {right arrow over (κ)} g 1 *({right arrow over (κ)}; {right arrow over (ρ)} 1 )g 2 ({right arrow over (κ)}; {right arrow over (ρ)} 2 )| 2 =|G 12 (1) ({right arrow over (ρ)} 1 , {right arrow over (ρ)} 2 )| 2 gives the δ function of position-position correlation
[0000]
∫
κ
→
g
1
*
(
κ
→
;
ρ
→
1
)
g
2
(
κ
→
;
ρ
→
2
)
2
≃
δ
(
ρ
→
o
+
ρ
→
i
)
2
,
(
9
)
g
1
(
κ
→
;
ρ
→
o
)
∝
Ψ
(
κ
→
,
-
c
ω
d
A
)
κ
→
·
ρ
→
o
,
g
2
(
κ
→
;
ρ
→
i
)
∝
Ψ
(
κ
→
,
-
c
ω
d
B
)
κ
→
·
ρ
→
i
,
where
(
10
)
[0000] are the Green's functions propagated from the radiation source to the transverse planes of d A and d B =d A . In Eq. (10), ψ(ωd/c) is a phase factor representing the optical transfer function of the linear system under the Fresnel near-field paraxial approximation, ω is the frequency of the radiation field, and c is the speed of light.
[0051] Substituting this δ function together with the constant G 0 into Eq. (1), an equal sized lensless image of A({right arrow over (ρ)} 0 ) is observed in the joint detection between the CCD array and the photon counting detector D 1 . The visibility of the image is determined by the value of G 0 .
[0052] The ghost images are thus successfully interpreted as the result of two-photon interference. The two-photon interference results in a point-point correlation between the object plane and the image plane and yields a ghost image of the object by means of joint photodetection.
[0053] As shown in FIG. 5A , and disclosed in more detail in U.S. Pat. No. 7,812,303, a quantum ghost imaging system comprising an arbitrary random, spatially correlated light source 12 in an air medium as the source of the illuminating light. Radiation from a chaotic pseudothermal source 12 is divided into two paths by a nonpolarizing beam splitter 28 , which divides the light into paths 13 and 21 . In path A, an object 14 is illuminated by the light source at a distance of d A . The object 14 receives a light source output 13 and reflects light along 15. The reflected light output 15 , reflected from the surface of the object, is collected by a “bucket” detector 16 and integrated for some exposure time. The bucket detector 16 is simulated by using a large area silicon photodiode for collecting the randomly scattered and reflected photons from the object 14 . The integrated values of the intensity are transmitted via interconnection 17 to the two-photon correlation computation subsystem 18 . In path B, a second spatially addressable detector 22 is deployed. Output 21 is collected by a spatially addressable detector 22 that is observing the source 12 for the same exposure time at 16 . The detector 22 includes a two-dimensional (2D) photon counting CCD array, cooled for single-photon detection, and may optionally include a lens. A triggering pulse from a computer is used to synchronize the measurements at 16 and 22 for two-photon joint detection. The time window is preferably chosen to match the coherent time of the radiation to simplify computation. The light intensity is also preferably chosen for each element of the detector 22 working at a single-photon level within the period of detector element response time. The chaotic light 12 is simulated by transmitting a laser beam first through a lens to widen the beam and then through a phase screen made from rotating ground glass. The detector 22 is placed at any given distance d B . As shown in FIG. 5A , d A =d B . It can be appreciated, however, that the present invention is operative when d B does not equal d A . The detector 22 faces the light source instead of facing the object 14 . The spatially addressable intensity values are transmitted via interconnection 23 to the two-photon correlation computation subsystem 18 . The two-photon correlation computation subsystem 18 comprises a voltage output recorder, coincidence circuit and CDCD output recorder. Subsystem 18 computes the two-photon correlation quantum ghost image in accordance with Eq. 3 utilizing the input values from interconnections 17 and 23 .
[0054] Additionally, electronic circuitry components of the computer relative to the detectors 16 and 22 comprise a coincidence circuit which provides detection coordination between detectors 16 and 22 . A photon registration history for detector 16 is also provided, which provides a temporal log for the integrated values 17 transmitted to the computer 18 A. The second spatially addressable detector 22 is provided with spatially addressable output that is subsequently fed to the computer and onto a display (not shown). For the optical bench schematic of FIG. 5 A, the actual ghost image display on a monitor is provided in FIG. 5B and is discernable as the original toy figure. It can be appreciated that the image quality shown in FIG. 5B is improved by increasing photon flux along path 15 .
[0055] To confirm the ability to generate a ghost image of an object through an obscuring medium, an obscuring medium of frosted glass is inserted along the optical path 15 of FIG. 5A . FIG. 6A is an instantaneous image of the light source 12 collected on the detector 22 (using the target ARL). FIG. 6B is an averaged image of the light source 12 obtained from detector 22 on averaging of 100 such images according to FIG. 6A . FIG. 6C is a G (2) image of the object obtained by correlation to photon ghost imaging from signals 17 and 23 . The instantaneous image of the obscured reflection object 14 is provided in FIG. 6D while the averaged image of the obscured reflection object 14 is provided in FIG. 6E .
[0056] FIGS. 7 and 8 depict an inventive ghost imaging system in which the object is a semi-opaque mask 14 ′ providing a transmissive photon output 46 to reach the bucket detector 16 . In FIG. 8 , the mask 14 ′ is a stencil of the letters “ARL”. The detector 22 in this regime of FIGS. 7 and 8 is a two-dimensional charge couple device array that provides two-dimensional speckle data as the spatially addressable intensity values 23 to the computer 18 A with gated electrical values being communicated to the computer 18 A with gated exposure start and stop triggers being communicated to the detectors 16 and 22 . The object 14 ′ is located a distance d′ A from the bucket detector 16 .
[0057] In accordance with a preferred embodiment, as depicted in FIG. 8 , the laser source 12 in conjunction with the rotating phase screen diffuser 40 , emits light uncorrelated in space and time. Thus, the speckle images 23 are random distributions in space and time. The beam splitter 28 essentially “halves” the intensity of the initial speckle image from diffuser 40 and splits it into two different paths ( 21 and 13 ) as shown in FIG. 8 . Spatially correlated means that correlations are present at any given instant of time between the two paths 13 , 21 . There will be a point to point correlation between the speckle images on each path, although paths are spatially distinct. The coincidence detection by the processor 18 is temporal; i.e. correlated at specific time intervals. “Correlation” or “Correlated,” as used in the present application, means a logical or natural association between two or more paths; i.e., an interdependence, relationship, interrelationship, correspondence, or linkage. For example, the present invention may be used in conjunction with sunlight, an incoherent light source, whereby a first and second plurality of photons are emitted from the sun at the same time. If the first detector is located on the earth (ground) receives the first plurality of photons, and the second detector located in space (such as in a satellite orbiting the earth) receives a second plurality of photons, the time intervals need to be synchronized; i.e., a first plurality of photons which strikes the ground object is correlated with a second plurality of photons detected in space at synchronized timing intervals. It can be readily appreciated by those skilled in the art that if the detected samples from the first and second plurality of photons are not part of the correlation, it will not contribute to the G (2) image as mathematically described in the above equations. Further, coincidence has to do with two measurements at the same or approximately the same time. For example, when a coincidence occurs, one must compensate for the media involved to take into account the variation in particle velocity between different media.
[0058] In FIG. 8 , the mask 14 ′ is a stencil of the letters “ARL”. The detector 22 in this regime of FIGS. 7 and 8 is a two-dimensional charge couple device array that provides two-dimensional speckle data as the spatially addressable intensity values 23 to the computer 18 A with gated electrical values being communicated to the computer 18 A with gated exposure start and stop triggers being communicated to the detectors 16 and 22 . The object 14 ′ is located a distance d′ A from the bucket detector 16 .
[0059] In accordance with the embodiment depicted in FIG. 8 , the laser source 12 in conjunction with the rotating phase screen diffuser 40 , emits light uncorrelated in space and time. Thus, the speckle images 23 are random distributions in space and time. The beam splitter 28 essentially “halves” the intensity of the initial speckle image from diffuser 40 and splits it into two different paths ( 21 and 13 ) as shown in FIG. 8 . Spatially correlated means that correlations are present at any given instant of time between the two paths 13 , 21 . There will be a point to point correlation between the speckle images on each path, although paths are spatially distinct. The coincidence detection by the processor 18 is temporal; i.e. correlated at specific time intervals. “Correlation” or “Correlated,” as used in the present application, means a logical or natural association between two or more paths; i.e., an interdependence, relationship, interrelationship, correspondence, or linkage. For example, the present invention may be used in conjunction with sunlight, an incoherent light source, whereby a first and second plurality of photons are emitted from the sun at the same time. If the first detector is located on the earth (ground) receives the first plurality of photons, and the second detector located in space (such as in a satellite orbiting the earth) receives a second plurality of photons, the time intervals need to be synchronized; i.e., a first plurality of photons which strikes the ground object is correlated with a second plurality of photons detected in space at synchronized timing intervals. It can be readily appreciated by those skilled in the art that if the detected samples from the first and second plurality of photons are not part of the correlation, it will not contribute to the G (2) image as mathematically described in the above equations. Further, coincidence has to do with two measurements at the same or approximately the same time. For example, when a coincidence occurs, one must compensate for the media involved to take into account the variation in particle velocity between different media.
[0060] FIG. 9 is a perspective schematic of a reflective ghost imaging scheme according to the present invention using light emitting diodes as a representative incoherent light source in a field setting and insensitive to transmission through obscuring medium. Similarly, solar radiation as a light source, as described in further detail in U.S. Pat. No. 7,812,303, hereby incorporated by reference.
[0061] A preferred embodiment of the present invention may utilize a light source emitting radiation that is one of an entangled, thermal, or chaotic light source. The photons from the light source may be divided into two paths: one path for the object to be imaged, and the other path in which images of the entangled, thermal, or chaotic light are measured independent of interaction with the objects. Any or all paths may pass through an obscuring medium. The measurements of the entangled, thermal, or chaotic light may then stored for future processing. In U.S. Pat. No. 7,812,303, the light in the object path is collected into a bucket detector and measured. The measurements of the bucket detector are then stored for future processing. A process for solving for the G (2) Glauber coherence between the two paths is provided to reconstruct the image. The G (2) Glauber coherence between the two paths is used to generate a correlation two-photon ghost image.
Non-Line-of-Sight-Ghost-Imaging
[0062] FIG. 10 is schematic depiction of an experimental set-up for quantum imaging “absent-line-of-sight,” including photon probability paths from the illuminated target. During this experiment, only the photons that were measured in the white outlined area 31 were used. The white outlined area contained no spatial patterns about the “ARL” target because only photon counts were measured by a non-resolving single pixel bucket detector 16 . The “ARL was not in the line-of-sight of the bucket detector 16 . The photon counts inside the white outlined area 31 were used as the “bucket” measurements. Computing the G (2) correlations using the bucket measurements and the coincidentally measured reference frames produced the Ghost image of ARL in FIG. 12 . This experiment was conducted under conditions of extreme turbulence in all of the paths for both the reference and the target (as shown in FIG. 10 ). However, the technique can be utilized with or without turbulence. Compressive Imaging (CI) methods were used to compute the G (2) ghost image; however, similar images could be produced using direct Glauber G (2) computations. As explained in detail above, the G (2) image of the object is obtained by correlation to photon ghost imaging from signals produced by bucket detector 16 and imager 22 . The imager 22 may be a CCD, digital camera, video camera, scanner, or the like. Similarly, the detector 16 may comprise a bucket detector or CCD, digital camera, video camera, scanner, or the like which is configured to count photons (i.e., record energy imparted by photons). The two-photon correlation computation subsystem 18 comprises a voltage output recorder, coincidence circuit and CDCD output recorder. Subsystem 18 computes the two-photon correlation quantum ghost image in accordance with Eq. 3 utilizing the input values from elements 16 and 22 .
[0063] In the preferred embodiment depicted schematically in FIG. 10 , a “Ghost Image” an object is obtained that is not in the direct line of sight or field of view of the viewer, which may be for example, a bucket detector 16 . When a bucket detector is aimed nearby the object at location 31 , then a “Ghost Image” of part or the entirety of the object is generated, even in the presence of turbulence which might otherwise be disruptive to image generation. Scattering of quantum particles such as photons off the object, such as the location depicted in the oval 31 , carries information of the object shape even when the quantum particles such as photons of light do not go directly to the bucket detector 16 . The bucket detector 16 picks up quantum information on the object shape and its temporal relations to separate reference fields. The reference fields are recorded by an imager 22 (CCD, or camera, etc.) that looks at the light source 12 but not the object. FIG. 13 is the result of ensemble integration of all the reference field measurements for 10,000 frames. The embodiment of FIG. 10 comprises the computer 18 A which functions in a manner described with respect to FIG. 8 above. However, in FIG. 8 the target 14 is a mask. In the embodiment of FIG. 10 , the target 14 ′ appears on a piece of paper on which the letters ARL are printed. The paper was approximately 1.7 m from the detector 16 .
[0064] FIG. 11 is a low resolution average image “ARL” bucket target area for 10,000 frames. The non-line-of-sight “bucketing” area 31 was located within the box outlined in white. All of the frames were imaged through high levels of turbulence. As depicted in FIG. 11 , the invention was observed to work even when the bucket detector 16 was aimed at a region to the side of the ARL (shown as area 31 in FIG. 11 ) that was coplanar with the object, i.e., the ARL appeared on a piece of paper and the bucket detector was directed to the paper at the location labeled 31 in FIG. 11 .
[0065] In connection with FIG. 11 , the ARL target was produced using a 10 point bold Arial font colored white, with black background, actual printed size. The ARL target was printed in white using an Arial 10 point font bold capital letters. To obtain a perspective as to scale, given that a single font is 0.3527 mm, the height was approximately 3.527 mm. The measured distance from the beginning of the A to the end of the letter “L” is approximately 9 mm. The width of the rectangle 31 was approximately 1.25 mm and the height was approximately 1.75 mm. The rectangle 31 was approximately 2 mm from the upright portion of the “L.”
[0066] The paper 14 ′ in FIG. 11 is translucent with an approximate weight of 20 pounds per 500 basis ream with a brightness value of 92 on a TAPPI Brightness scale of 1 to 100. The paper in FIG. 11 was mounted on white cardboard backing. The paper 14 ′ was semi-shiny to visible light laser illumination and had a thickness of 0.097 mm.
[0067] Translucent objects allow the light to enter the material, where it is scattered around in a manner that depends on the physical properties of the material like the absorption coefficient (a) and the scattering coefficient (s), as described further in “Acquisition of Subsurface Scattering Objects,” a Diploma Thesis by Christian Fuchs, Max-Planck-Institut für Informatik, Saarbrücken, Germany (date appearing on thesis is Feb. 9, 2006). Accordingly light may enter the material for subsurface scattering, including single scattering as described further in “Acquisition of Subsurface Scattering Objects,” hereby incorporated by reference. Moreover, concepts relating to a general bidirectional surface scattering distribution function (BSSRDF), relating to light transport, is described further in “A Practical Model for Subsurface Light Transport,” hereby incorporated by reference.
[0068] The image of ARL, like any other object, may be generated even in the presence of turbulence which might otherwise be disruptive to image generation. A description of the effect of turbulence and compression of images may be found in Meyers, et al, “Ghost Imaging Experiments at ARL,” Quantum Communications and Quantum Imaging VIII, Proc. Of SPIE Vol. 7815, 781501 (2010), and R. Meyers, K. Deacon, and Y. Shih, “Turbulence-free ghost imaging,” App. Phys. Lett, 98, 111115 (2011), both of which are hereby incorporated by reference. Scattering of quantum particles such as photons off the object (in this case “ARL”) carries information of the object shape even when the quantum particles such as photons of light do not go directly to the bucket detector 16 . The bucket detector 16 picks up quantum information on the object shape and its temporal relations to separate reference fields. The reference fields are recorded by an imager 22 (CCD, or camera, etc.) that looks at the light source but not the object. The preferred embodiment depicted in FIG. 10 was observed to work when the bucket detector was aimed at the region 31 in FIG. 11 , which is to the side of the object (ARL) that was coplanar with the object (ARL).
[0069] It is noted that where the bucket detector 16 is referenced herein, a camera may be used the output of which can be converted to nonspatial output in a manner similar to a bucket detector without departing from the scope of the present invention.
[0070] When a detector 16 is aimed nearby the object but not at the object then a Ghost Image of part or the entirety of the object is generated. The object is generated even in the presence of turbulence which might otherwise be disruptive to image generation. Scattering of quantum particles such as photons off the object carries information of the object shape even when the quantum particles such as photons of light do not go directly to the bucket detector. The detector 16 picks up quantum information on the object shape and its temporal relations to separately referenced fields are recorded by an imager 22 (CCD, or camera, etc.) that “looks” at the light source but not the object. The invention was observed to work even when the bucket detector was aimed at a region to the side of the object that was coplanar with the object.
[0071] Patent documents and publications mentioned in the specification are indicative of the levels of those skilled in the art to which the invention pertains. These documents and publications are incorporated herein by reference to the same extent as if each individual document or publication was specifically and individually incorporated herein by reference.
[0072] The preferred embodiments of the present invention may be used for active and passive illumination and determination of 3D structure from single views to mitigate enemy cover, concealment, and camouflage. Further potential applications include persistent surveillance applications, stealthier, and more robust situational awareness for urban warfare, UAV and robotic surveillance, persistent surveillance, and IED surveillance. Improved medical imaging will result since bone will be less effective in shielding soft tissue from imaging detectors.
[0073] As used herein the terminology processor includes a computer, microprocessor, multiprocessor, central processing unit, CPU, controller, mainframe, signal processing circuitry, or a plurality of computers, processors, microprocessors, multiprocessors, controller, CPUs, or mainframes or combinations thereof and/or equivalents thereof.
[0074] As used herein, the terminology “object” may include visual information, an image, printed matter, subject, a plurality of objects, material, surface, wall, poster, paper, picture, or anything similar.
[0075] As used herein the terminology “diffuse reflection” means reflection of light, sound, or radio waves from a surface in all directions. Diffuse reflection is the reflection of light from a surface such that an incident ray is reflected at many different angles, rather than at one precise angle, as is the case for specular reflection. If a surface is completely nonspecular, the reflected light will be evenly spread over the hemisphere surrounding the surface (2×π steradians).
[0076] As used herein the terminology “CCD” means charge-coupled device, a high-speed semiconductor used chiefly in image detection. Digital cameras, video cameras, and optical scanners all use CCD arrays.
[0077] As used herein the terminology “nonspatial photon detector” means a detector (such as a bucket detector) of photons that has no spatial resolution.
[0078] As used herein the terminology “spatial light detector” or “spatial receiver” means a detector or receiver capable of resolving spatial information from the light or quantum particles received.
[0079] Although various preferred embodiments of the present invention have been described herein in detail to provide for complete and clear disclosure, it will be appreciated by those skilled in the art that variations may be made thereto without departing from the spirit of the invention.
[0080] It should be emphasized that the above-described embodiments are merely possible examples of implementations. Many variations and modifications may be made to the above-described embodiments. All such modifications and variations are intended to be included herein within the scope of the disclosure and protected by the following claims.
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A system and method for obtaining an image of an object out of line of sight, the method comprising directing a chaotic light beam at a first area containing the object; measuring the light from the chaotic light beam at a plurality of instances in time; using a photon detector, detecting light from a second area over a plurality of instances in time; the photon detector not being in the line of sight with the first area but in line-of-sight with a second area; using a processor, correlating the information received by the photon detector with the measurement of light from the chaotic light beam at specific instances in time; and producing an image of the object. The system for imaging information comprising a spatial receiver, a chaotic photon light source for producing light; the light comprising a first beam adapted to be directed at a first predetermined area containing an object, and a second beam which is received by the spatial receiver and measured at specific intervals in time; at least one processor operatively connected to the spatial receiver, the spatial receiver operating to transmit spatial information correlated to specific intervals of time to the processor; and a first receiver operatively connected to the at least one processor and operative to detect the influence of the object on the first portion of the light beam; the first receiver not being in the line of sight with the first predetermined area and adapted to detect light from a second predetermined area spaced from and coplanar with the first predetermined area, the at least one processor operating to correlate the outputs of the first receiver with spatial information derived from the spatial receiver at correlating intervals of time to create an image of the object.
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BACKGROUND OF THE INVENTION
This invention relates to a vehicle with a fuel cell system and more particularly to an improved fuel cell powered vehicle.
With the concern for the environment and the dwindling sources of petroleum based fuels, there has been considerable emphasis on alternative power sources for many applications including vehicles. The fuel cell is one such alternative source which is receiving a considerable amount of attention. However, present vehicles powered by fuel cells have tended toward large vehicles such as buses wherein the fuel cells are located in a relatively exposed position and can be subject to damage.
There is, however, a need for a smaller type of vehicle that can be powered by a fuel cell and in which the fuel cell will be adequately protected. In addition, with such small vehcles, it is desirable to insure that the stability of the vehicle be maintained.
It is, therefore, a principal object of this invention to provide an improved fuel cell powered wheeled vehicle.
It is a further object of this invention to provide a fuel cell powered wheeled vehicle wherein the fuel cell is located in such a manner so as to maintain stability of the vehicle.
It is a further object of this invention to provide a fuel cell powered vehicle wherein the fuel cell is located in an appropriate condition to maintain stability.
It is a further object of this invention to provide a fuel cell powered vehicle wherein the fuel cell is located in such a way that it will be inherently protected from damage.
In connection with the use of fuel cells for powering small vehicles, the placement of the fuel cell presents certain difficulties, as aforenoted. In addition to maintaining good stability for the vehicle, the fuel cell which may be somewhat bulky, should be positioned in such a location that it will not interfere with the useful space of the vehicle.
It is, therefore, a further object of this invention to provide an improved arrangement for a small vehicle powered by a fuel cell wherein the fuel cell will be positioned in an out of the way place and which will not encroach upon the useful space of the vehicle.
As is well known, fuel cells normally employ a number of closely spaced plates, such as plates of carbon composition that coooperate to generate electrical power. However, in addition to the normal vibrations encountered in a vehicle, most vehicles generally are designed so as to operate up and down inclines and also in such a way that the vehicle will be displaced or lean relative to the horizontal. Of course, such motion can adversely affect fuel cells and specifically the plates thereof.
It is, therefore, a still further ofject of this invention to provide a fuel cell powered vehicle wherein the fuel cell is located in such an orientation so as to minimize the likelihood of damage to the fuel cell due to vehicle operation.
SUMMARY OF THE INVENTION
This invention is adapted to be embodied in a fuel cell lowered vehicle that has a body assembly which defines at least one passenger seat, a pair of wheels suspended by the body at one end thereof in transversely spaced apart relation and at least one wheel suspended by the body assembly at the other end thereof. Means are provided for steering at least one of the wheels. A fuel cell is carried by the body assembly and generates electrical power for driving at least one of the wheels.
In accordance with a first feature of the invention, the fuel cell is supported contiguous to the center of gravity of the vehicle.
In accordance with another feature of the invention, the fuel cell is positioned inwardly from the vehicle wheels toward the center when the vehicle is viewed in a horizontal plane so as to protect the fuel cell.
In accordance with another feature of the invention, the fuel cell is positioned beneath the seat of the vehicle so as to not encroach upon the usable space of the vehicle.
In accordance with yet another feature of the invention, the fuel cell is positioned in the vehicle with its plates extending in a horizontal direction so as to minimize the likelihood of damage due to vehicle operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view, with a portion broken away, of a small fuel cell powered vehicle constructed in accordance with an embodiment of the invention.
FIG. 2 is a side elevational view thereof.
FIG. 3 is an enlarged top plan view showing the fuel cell and the mounting arrangement therefor.
FIG. 4 is a side elevational view of the fuel cell.
FIG. 5 is a further enlarged top plan view of the area encompassed by the circle 5 in FIG. 3.
FIG. 6 is a cross-sectional view taken along the line 6--6 of FIG. 5.
FIG. 7 is a side elevational view, in part similar to FIG. 2, showing another embodiment of the invention.
FIG. 8 is a top plan view, in part similar to FIG. 1, with portions broken away, of this embodiment.
FIG. 9 is a top plan view, in part similar to FIGS. 1 and 8, with a portion broken away, showing yet another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to the embodiment of FIGS. 1 through 6 and initially to FIGS. 1 and 2, a small fuel cell powered vehicle constructed in accordance with this embodiment of the invention is identified generally by the reference numeral 11. As will be noted, the vehicle 11 is designed to accommodate a pair of riders and may be, for example, a golf cart. However, the vehicle 11 will, as should be readily apparent to those skilled in the art, permit itself to be employed as a commuter type vehicle in addition to such utilization as a golf cart.
The vehicle 11 includes a body assembly, indicated generally by the reference numeral 12, which may be fabricated in any known manner and which may include a separate or integral frame assembly. A pair of dirigible front wheels 13 are supported at the forward end of the body assembly 12 by means of a suitable suspension and steering mechanism. A pair of rear wheels 14 are journaled at the rear of the body assembly 12, also in an appropriate manner. The rear wheels 14 are driven through a differential by means of an electric motor (not shown). This electric motor may be mounted in any suitable location and conveniently can be located immediately adjacent the axle of the rear wheels 14. The vehicle 11 is adapted to operate along the ground, the line of which is shown at 15, and which may be of any type of terrain including uphill and downhill and inclined sections.
The body assembly 12 defines an internal passenger compartment 16 that has a forwardly mounted steering wheel 17 for steering the front wheels 13 as aforenoted. In addition, other appropriate controls such as speed control and brake are positioned appropriately within the passenger compartment 16. An operator seat 18 and passenger seat 19 are mounted on a raised plateform 21 formed in the passenger compartment 16 to the rear of the steering wheel 17. An operator and passenger may be accommodated on the seats 18 and 19.
For safety purposes, the vehicle is provided with a front bumper 22 and a rear bumper 23 which bumpers may be affixed to the body 12 in a suitable manner including shock absorbing or impact absorbing assemblies.
The vehicle 11 and specifically its driving electric motor is adapted to be powered by a fuel cell assembly, indicated generally by the reference numeral 24, and which is positioned beneath the raised platform 21 and specifically beneath the operator's seat 18. The fuel cell assembly 24 is located so that it will be spaced inwardly from the wheels 13 and 14 toward the center of the vehicle and specifically adjacent its center of gravity W. This will insure good stability for the vehicle as well as protection for the fuel cell assembly 24.
Referring now in detail primarily to FIGS. 3 through 6, the fuel cell assembly 24 includes a fuel cell 25 which may be of any known type but which is disposed in the body assembly 12 so that its internal plates extend in a horizontal direction. Because of this orientation, the fuel cell 25 will be protected against damage due to vibrations and change of grade which effect either up or down movement or leaning to the right or to the left.
The fuel cell 25 is mounted on a mounting plate 26 in a somewhat inclined direction to the fore and aft longitudinal center line of the vehicle 11 as may be best seen in FIGS. 1 and 3. This mounting plate 26 is, in turn, mounted on a subframe assembly, indicated generally by the reference numeral 27, by means of four spaced elastic isolators 28. The isolators 28 include elastomeric rings which are interposed around threaded fasteners that extend between the mounting plate 26 and the subframe 27. It should be noted that the fuel cell 25 is disposed to one side of the subframe 27.
The fuel cell assembly 24 also includes a reformer 29 which is mounted appropriately on the subframe 27 and which receives fuel to be reformed, such as a mixture of methanol and water from a fuel storage tank 31 that is positioned within the body assembly 11 to the rear of the passenger compartment 16. This fuel is delivered to the reformer 29 in an appropriate manner so as to be converted into a hydrogen rich fuel for the fuel cell 25.
As is well known, the reformer includes a catalyst bed and a lower heater unit or burner 32 which burns the methanol fuel and which receives air from a blower 33 which is also mounted upon the frame assembly 27 in an appropriate manner. The exhaust gases from the reformer 29 are delivered to the atmosphere through an exhaust pipe 34 which exits at the rear of the vehicle 12 in proximity to the rear bumper 23.
Also mounted on the subframe 27 is a blower 35 for forcing air into the fuel cell 25 for its reaction operation. The exhaust gases from the fuel cell 25 are also discharged to the atmosphere through an exhaust pipe 36 that extends rearwardly and which terminates adjacent the rear bumper 23.
The subframe 27 is mounted at its forward end on the floor 37 of the vehicle body assembly 12 by means of a pair of elastic isolators 38 which are attached to the front of the subframe 27 and to a pair of upstanding arms 39 of the body assembly floor pan 37. A pair of similar isolator assemblies 41 and having a construction as shown in FIGS. 5 and 6 are interposed between the rear of the subframe 27 and the floor pan 37. These isolator assemblies 38 and 41 comprise elastomeric rings 42 that have plates bonded to their ends from which studs 43 extend so as to permit the elastic isolator 41 to be attached to the subframe 27 and floor pan 37 in a known manner.
There are times when the fuel cell assembly 24 may not generate adequate electrical power for motivation of the vehicle 11. There are also times when the fuel cell assembly 24 generates excess electric power. Therefore, there are provided a series of batteries 44 that are positioned beneath the raised body portion 21 and specifically beneath the passenger seat 19. These batteries 44 are selectively charged or discharged through a controller assembly 45 so that during times when the fuel cell assembly 24 is generating excess electrical power, the batteries 44 will be charged and during times when insufficient electrical power is being generated, the batteries 44 can supply additional electrical power for the driving motor.
The subframe assembly 27 further includes a reinforcing member 46 that is affixed to the rear end thereof and which extends upwardly so as to protect the rear portion of the fuel cell assembly 24.
In the embodiment of the invention as thus far described, the vehicle 11 has been described as a golf cart or smaller utility vehicle. FIGS. 7 and 8 show a further embodiment of the invention which is generally the same as the embodiment thus far described but which is primarily designed for use as a golf cart. In this embodiment, the vehicle, indicated generaly by the reference numeral 51, has all of the major components the same as the vehicle as thus far described. Where that is the case, these components have been identified by the same reference numeral and further description is believed to be unnecessary.
In connection with this vehicle, the passenger compartment 16 is moved forwardly although the fuel cell assembly 24 is still positioned close to the center of gravity of the vehicle and beneath the driver's seat 18. In this embodiment, the batteries 44 are disposed beneath the passenger seat 19. A golf club rack 52 is carried at the rear of the passenger compartment and is designed to accommodate a plurality of golf bags shown in phantom and identified by the reference numeral 53.
FIG. 9 shows another embodiment of the invention which is basically the same as the embodiment of FIGS. 1 through 6. For that reason, components of the vehicle which are the same have been identified by the same reference numeral. In this embodiment, however, the vehicle, indicated generally by the reference numeral 101, is laid out in its passenger compartment so that the fuel cell assembly 24 lies along a longitudinal center line 102 of the vehicle and hence is positioned between the driver's seat 18 and passenger seat 19 rather than under the driver's seat 18 as in the previously described embodiment. However, it is to be understood that the invention can be utilized in conjunction with vehicles have bench type seats and then the fuel cell assembly 24 would be positioned under this seat. Because of this location for the fuel cell assembly 24, which is still closely adjacent the center of gravity W as well as being on the longitudinal center line 102. Because of this positioning, the storage batteries 44 are nested around the fuel cell assembly 24 rather than on one side of it. In all other regards, this embodiment is the same as the embodiment of FIGS. 1 through 6.
It should be readily apparent from the foregoing description that the described embodiments provide very compact vehicles powered by fuel cell assemblies and in which the fuel cells are disposed closely adjacent the center of gravity of the vehicle and inwardly of the wheels to be protected. In addition, the fuel cell is disposed so that its plates extend longitudinally in horizontal planes so as to avoid damage. In this regard, the invention has been described in conjunction with arrangements with a single fuel cell 24. It is to be understood, however, that the invention can be utilized in conjunction with multiple fuel cells, one stacked upon the other in a vertical orientation. Of course, other orientations can be utilized so long as the aforenoted principles are employed.
In addition to those embodiments illustrated and described, which are the preferred embodiments, various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims.
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A number of embodiments of fuel cell powered wheeled vehicles wherein the fuel cell assembly is positioned contiguous to the center of gravity of the vehicle and inwardly from the wheels for protection and to make a compact assembly. Various vehicle arrangements are shown and in all of them the fuel cell assembly including the fuel cell and a reformer are supported resiliently on the body beneath the seats thereof.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a chain drum locking mechanism for a manual rolling door operator, such that when a force is exerted on a chain to rotate the chain drum, a curtain of rolling door can be lifted up or lowered down; but when the exerting of the force is stopped, the rolling door can be locked immediately.
[0003] 2. Brief Description of Prior Arts
[0004] For a conventional rolling door operator, it is always provided with a preloading mechanism according to the weight of a curtain of slats, to balance partial weight of the door slats. For example, the weight of the preloading weight is controlled between +35 and −35 lbs. Within this range, when manually pushing the door curtain upward or drawing the door curtain downward, manual operation of the rolling door is very easy to conduct.
[0005] Furthermore, the conventional door operator is often provided with a brake device. It is true that the brake device can stop free dropping of the curtain of door slats when manual force exertion is stopped. However a clutch mechanism is needed to release the brake device from locking when the curtain of door slats is to start to operate. As such, this kind of the mechanism of the door operator not only is complicated, bulky and inconvenience in change-over of operation, but also its cost is high and failure rate is high.
[0006] For example, a Taiwanese Patent Application No. 100134526 (corresponding to U.S. patent application Ser. No. 13/354,368) entitled “Door machine having chain disk locking mechanism” and filed by the inventor of the present invention, discloses an electric door operator, comprising an electric motor, having a drive shaft; and a chain drum locking mechanism, mainly comprising a chain drum, a wedge wheel, a stationary shaft and a plurality of moving rollers. The chain drum comprises a chain wheel, a wall drum, a central recessed socket and a plurality of fixed rods. The wall drum is fixed at one side of the chain wheel and has a central axial aperture. The chain wheel includes a hollow cavity in which the central recessed socket is freely to be received, and the central recessed socket is fixed on an outer case body and defines a central circular bore. The plural fixed rods are axially located within the central circular bore and are fixed on the wall drum. The wedge wheel is received within the central circular bore, and includes a plurality of axial open slots corresponding to the plurality of fixed rods, each axial open slot including one first end face and two second end faces, in which the two second end faces are respectively provided at two sides of the first end face. The first end face is spaced from the inner wall of the central circular bore by a first pitch, and the second end faces are spaced from the inner wall of the central circular bore by a second pitch respectively, in which the first pitch is smaller than the second pitch. Further, one end of a stationary shaft is pivotally connected to the drive shaft of the electric motor, and the other end of the stationary shaft passes freely through the central axial bore of the chain drum and is fixed to the wedge wheel. The plurality of moving rollers are respectively received in the plurality of axial open slots of the wedge wheel, and are interposed between the second end faces within the inner walls of the central circular bore. The diameter of each moving roller is larger than the first pitch and is smaller than the second pitch. The diameter of each fixed rods is smaller than the first pitch. When the chain drum is rotated, the plurality of fixed rods push against the moving rollers so as to move the wedge wheel and simultaneously to rotate the drive shaft; when the stationary shaft is to be rotated, the first end face of the wedge wheel and the inner wall of the central circular bore lock the plurality of moving rollers, so that the stationary shaft is unable to rotate.
[0007] Under a manual operation mode of the electric door operator, when the chain drum is manually pulled, the rolling door is lifted up or lowered down; when the pulling is stopped, the brake is in action and is locked so that the rolling door is unable to be lifted up or lowered down. Hence, there is no need to use a conventional clutch for change-over. Therefore, not only the clutch mechanism can be omitted to reduce cost but also the elements of the mechanism can be simplified and assembly as well as maintenance is easier. Thus, the lifetime can be prolonged.
[0008] Furthermore, the inventor contemplates to allow the chain drum locking mechanism to combine with a planetary reduction mechanism, so that a simple manual rolling door operator is formed with the component parts fewer and the volume smaller.
SUMMARY OF THE INVENTION
[0009] The main object of this invention is to provide a chain drum locking mechanism for manual rolling door operator, whereby, when the chain drum is pulled, the curtain of slats of the rolling door is lifted up or lowered down; and when the pulling of a chain is stopped, the curtain of slats of rolling door stops immediately at desired position without free dropping. Hence, there is no need to use conventional clutch for change-over.
[0010] Another object of the present invention is to provide a chain drum locking mechanism for manual rolling door operator, whereby a conventional clutch mechanism can be omitted, the structure thereof can be simplified, the assembly as well as the maintenance thereof is more easier, and the lifetime can be prolonged.
[0011] Still another object of the present invention is to provide a chain drum locking mechanism for manual rolling door operator, in which the chain drum locking mechanism is received in a central circular bore to cooperate the planetary reduction mechanism. Hence, the size of the rolling door operator can be made to be flattened and compact to be enable to be received in a limited space.
[0012] In order to achieve the above and the other objects, the chain drum locking mechanism for manual rolling door operator according to the present invention is provided, which comprises a stationary base plate, a chain drum locking mechanism, and a reduction mechanism. The reduction mechanism has an output shaft. The chain drum locking mechanism comprises a chain drum, a central recessed socket, a ring socket, a drive shaft, a wedge wheel, a plurality of fixed rods and a plurality of moving rollers. The central recessed socket is fixed on one side of the chain drum, and the central recessed socket has a central axial bore and an accommodation cavity. The ring socket is freely received within said accommodation cavity and is fixed to the stationary base plate, and the ring socket defines a central circular bore with the central recessed socket. The drive shaft has one end pivotally provided in the central axial bore of the central recessed socket, and the other end coupled to the output shaft of the reduction mechanism. The wedge wheel is fixed on the drive shaft and is received within the central circular bore. The wedge wheel includes a plurality of axial slots each of which includes two end portions and a protrusion interposed between the intersection of the two end portions, each end face having one side proximate to the protrusion having a first distance spaced from the inner wall of the central circular bore, and the other side far from the protrusion having a second distance spaced from the inner wall of the central circular bore, the first distance being smaller than the second distance. The stationary socket is received freely within the central circular bore and is located at the opposite side of the central recessed socket. A plurality of fixed rods are located in the plurality of axial slots. Each fixed rod is interposed between the protrusion and the inner wall of the central circular bore, and is fixed on the end face of the stationary socket opposite to the central recessed socket. A plurality of moving rollers are respectively received within the plurality of axial slots. Each moving roller is interposed between one of the end portions and the inner wall of the central circular bore.
[0013] Furthermore, the diameter of each moving roller is larger than the first distance and is smaller than the second distance, while the diameter of each fixed rod is smaller than the first pitch. When the chain drum is rotated, the plurality of fixed rods push the moving rollers so as to move the wedge wheel and simultaneously to rotate the drive shaft. When the rotation of chain drum stops, the end face portions of the wedge wheel and the inner wall of the central circular bore lock the plurality of moving rollers so that the driving shaft is unable to rotate.
[0014] Preferably, each of the axial slots includes two side walls respectively, and is provided with two liners respectively provided with a face having two end portions thereof; one end portion being vertically spaced from a corresponding point on the inner wall of the central circular bore by a first distance, the other end portion being vertically spaced from another corresponding point on the inner wall of the central circular bore by a second distance, and the first distance being smaller than the second distance. Each of the side walls has a compression spring assembled thereon to push the plurality of moving rollers away from the side walls. In this manner, the plurality of compression springs can push the plurality of moving rollers closely to the protrusion between the two end portions, so that the plurality of moving rollers can be locked in the first distance so as to lock the drive shaft. Therefore, the drive shaft is unable to rotate freely with respect to the chain drum.
[0015] Furthermore, the present invention comprises a planetary reduction mechanism. The stationary base plate has an annular gear. The reduction mechanism comprises: a first end drum located at one side of the annular gear and fixed to the stationary base plate; a second end drum located at the other side of the annular gear and fixed to the first end drum with each other, which defines a hollow accommodation cavity; a first wheel drum having a through aperture at its center, which is received within the accommodation cavity and located at one side of the annular gear; an output shaft having its first end extending in the accommodation cavity and having a second wheel drum integrally provided therewith; the second wheel drum and the first wheel drum being installed at the other side of the annular gear, and the second wheel drum and the first wheel drum being fixed together by a plurality of fixing pins, the output shaft having its second end extending along the outside of the second end drum and fixed with an output wheel; moreover, a plurality of planetary gears, via a plurality of pivot pins, pivotally disposed equiangularly on the opposite end faces of the first wheel drum and the second wheel drum and being meshed with the annular gear; and a drive shaft being pivotally installed in the through aperture of the first wheel drum, a sun gear correspondingly provided at the center of the annular gear being connected fixedly on the second end of the drive shaft, and the sun gear being meshed with the plurality of planetary gears. In this manner, the plurality of planetary gears rotating on the annular gear in spin and revolution. The implementation of planetary reduction mechanism not only has the advantages of small volume, light weight, high transmission efficiency, large loading capacity and compact size, but also controls the winding speed of lift-up or lower-down of the curtain of door slats.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
[0016] The present invention will be better understood by the detailed description of a preferred embodiment with reference to the accompanying drawings, in which:
[0017] FIG. 1 is a perspective exploded view of a manual rolling door operator relevant to the chain drum locking mechanism of the present invention.
[0018] FIG. 2 is a perspective view of the manual rolling door operator of FIG. 1 of the present invention in assembled state.
[0019] FIG. 3 is a perspective view of the manual rolling door operator of FIG. 2 viewed from another direction, in which it is partially sectioned and a chain runs along the chain drum.
[0020] FIG. 4 is a schematic view showing the application of the chain drum locking mechanism of the present invention in the manual rolling door operator.
[0021] FIG. 5 is a longitudinally sectional view taken along line 5 - 5 of FIG. 4 .
[0022] FIG. 6 is a sectional view taken along line 6 - 6 of FIG. 5 , in which the drive shaft in locking state is shown.
[0023] FIG. 6 a is a view showing that the drive shaft of FIG. 6 is in non-locking state, in which the arrow direction indicates the direction of force application on the chain drum.
[0024] FIG. 7 is a sectional view taken along line 7 - 7 of FIG. 5 , in which a schematic view of a planetary reduction mechanism is shown.
[0025] FIG. 8 is a schematic view showing the state of use of the manual rolling door operator in which the chain drum locking mechanism of the present invention is applied.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] Firstly, referring to FIGS. 1 to 3 , a preferred embodiment of a chain drum locking mechanism for manual rolling door operator of the present invention is shown. As shown, the rolling door operator 1 mainly comprises a stationary base plate 2 , a chain drum locking mechanism 3 , and a reduction mechanism 4 . The chain drum locking mechanism 3 is fixed on one side of the stationary base plate 2 , and the reduction mechanism 4 is installed on the other side of the stationary base plate 2 . An output shaft 41 is extended from the reduction mechanism 4 , and an output wheel 42 is provided on the output shaft 41 . The output wheel 42 is usually connected with a winding barrel Ds (as shown in FIG. 8 ) for a curtain of slats of rolling door through a chain, in which the reduction mechanism 4 is usually used to reduce the speed of lift-up and lower-down of the curtain of door slats (as shown in FIG. 8 ) driven by the output wheel 42 .
[0027] Referring to FIGS. 2 to 6 and 6 a , the chain drum locking mechanism 3 mainly comprises a chain drum 31 , a central recessed socket 33 , and a ring socket 34 . The chain drum 31 has a central aperture 311 . The central recessed socket 33 is fixed on the right side of the chain drum 31 (as seen from FIG. 1 ), and has a central axial bore 331 and an accommodation cavity 332 . The ring socket 34 has one end passing through the central aperture 311 and is loose fitted within the accommodation cavity 332 , and the other end of the ring socket 34 is fixed to the stationary base plate 2 . The ring socket 34 defines a central circular bore 341 . Although the chain drum 31 and the central recessed socket 33 are shown separately for the purpose of illustration, they can be integrally formed together if desired. A drive shaft 37 has its right end passing through the central circular bore 341 of the ring socket 34 and is pivotally provided in the central axial bore 331 of the central recessed socket 33 , and the left end of the drive shaft 37 is coupled to the output shaft 41 of the reduction mechanism 4 .
[0028] A wedge wheel 36 is fixed on the drive shaft 37 and is received within the central circular bore 341 . The wedge wheel 36 includes a plurality of axial slots 361 , and as shown in the embodiment, the number of the axial slots 361 is set three, for example. The three axial slots 361 are equidistantly spaced, each of the axial slots 361 including two bottom surfaces 362 separated by a central protrusion 363 . Preferably, liners 367 are respectively provided on the two bottom surfaces 362 , each liner 367 having a face Sf, the opposite sides of the face Sf being formed respectively as a first end portion P1 and a second end portion P2. The first portion P1 is proximate to the central protrusion 363 of the axial slot 361 and the second end portion P2 is far from the central 363 of the axial slot 361 . The first end portion P1 is vertically spaced from a corresponding point on the inner wall of the central circular bore 341 by a first distance D1, and the second end portion P2 is vertically spaced from another corresponding point on the inner wall of the central circular bore 341 by a second distance D2, the first distance D1 being smaller than the second distance D2.
[0029] A stationary socket 35 with three fixed rods 351 extending axially is received within the central circular bore 341 . The three fixed rods 351 pass through the three axial slots 361 of the wedge wheel 36 and are fixed on the bottom surfaces of the accommodation cavity 332 of the central recessed socket 33 . Further, six moving rollers 365 in pairs, are received within the three axial slots 361 of the wedge wheel 36 , each moving roller 365 being interposed in a space between the bottom surface 362 and the inner wall of the central circular bore 341 . The diameter of each moving roller 365 is larger than the first distance D1 and is smaller than the second distance D2, while the diameter of each fixed rod 351 is smaller than the first distance D1. As such, each fixed rod 351 can be moved freely in the whole axial slot 361 , each moving roller 365 is limited and locked by the first distance D1 but only can be slided in the direction of the second distance D2. Further, each of the axial slots 361 includes two side walls 364 respectively located at two sides of the axial slot 361 and adjacent to the second end portion P2 of the two bottom surfaces 362 respectively. Each of the side walls 364 has a compression spring 366 assembled thereon to push the pair of moving rollers 365 away from the side walls 364 .
[0030] Furthermore, referring to FIG. 7 , a planetary reduction mechanism 4 is shown for the chain drum locking mechanism 3 of the present invention. Referring to FIG. 1 , the stationary base plate 2 includes a through hole 20 provided with an annular gear 21 . The reduction mechanism 4 comprises a first end drum 43 located at the right side of the stationary base plate 2 , on which the ring socket 34 of the chain drum locking mechanism 3 is fixed; and a second end drum 44 located at the left side of the stationary base plate 2 . The second end drum 44 is fixed to the first end drum 43 with each other with the stationary base plate 2 fixed between the second end drum 44 and the first end drum 43 . The first end drum 43 , the second end drum 44 and the through hole 20 of the stationary base plate 2 define a hollow accommodation cavity 45 , as shown in FIG. 7 . A first wheel drum 46 having a through aperture 461 at the center, is received within the accommodation cavity 45 . The second end of the drive shaft 37 passes through the aperture 461 . A second wheel drum 47 is received within the accommodation cavity 45 . The output shaft 41 is extended from one side of the second wheel drum 47 . The other side of the second wheel drum 47 is fixed to the first wheel drum 46 by a plurality of fixing pins 471 . The output shaft 41 extends from the second end drum 44 and is fixed with the output wheel 42 which is coupled to the barrel Ds for the curtain of slats of the rolling door D, as shown in FIG. 8 . Three planetary gears 48 are disposed equidistantly on the second wheel drum 47 and pivot on pivot pins 49 within a space defined by the first wheel drum 46 and the second wheel drum 47 , and are meshed with the annular gear 21 of the stationary base plate 2 . A sun gear 38 is fixed on the left side of the driving shaft 37 and is disposed among the three planetary gears 48 and are engaged therewith. In this manner, the three planetary gears 48 revolve on the annular gear 21 , and hence the rotational speed of output wheel 42 from the sun gear 38 is reduced by spin or revolution of the planetary gears 48 .
[0031] An operation of the chain drum locking mechanism of the present embodiment is shown in FIG. 6 a . When the chain drum 31 is rotated in the clockwise direction as indicated by the black arrow, the three fixed rods 351 of the station socket 35 can push the three moving rollers 365 so that the three moving rollers 365 resist against the compression springs 366 disposed on the end walls 364 and slide in the direction of the larger second distance D2 at the second end portion P2 of the bottom surfaces 362 of slots. Hence, the moving rollers 365 rotate the wedge wheel 36 on the drive shaft 37 in the clockwise direction. On the contrary, when the chain drum 31 is rotated in counterclockwise direction as indicated by the white arrow, the three fixed rods 351 push the three moving rollers 365 to resist against the compression springs 366 disposed on the end walls 364 and slide in the direction of the smaller distance D1 at the second end portion P2 of the bottom surfaces 362 of slots. Hence, the moving rollers 365 rotate the wedge wheel 36 on the drive shaft 37 in the counterclockwise direction. However, when the chain drum 31 stops rotation either in the clockwise direction or the counter clockwise direction, the three moving rollers 365 are again moved by the corresponding compression springs 366 away from the side end walls 364 so as to slide and to be locked on the smaller first distance D1. Hence, the drive shaft 37 is locked without further ring rotation.
[0032] As such, according to this invention, a chain drum is integrated with a locking mechanism to omit a conventional clutch mechanism for a rolling door operator, and hence this invention can lock the door of slats from self dropping when a manual power is not exerted on the rolling door. Further, a planetary reduction mechanism for deceleration cooperates to control the winding or dewinding speed of lift-up or lower-down of the curtain of door slats. Therefore, the volume of the rolling door operator of the present invention can be made to be flattened and compact in such a manner as to be received in a limited space as shown in FIG. 8 . Moreover, as the construction of the structure is simple, the lifetime is significantly prolonged as high as over three hundred thousands times in switching-on and switching-off operation, and this is verified by experiment.
[0033] While the present invention has been described by preferred embodiments in conjunction with accompanying drawings, it should be understood the embodiments and the drawings are merely for descriptive and illustrative purpose, not intended for restriction of the scope of the present invention. Equivalent variations and modifications conducted by person skilled in the art without departing from the spirit and scope of the present invention should be considered to be still within the scope of the present invention.
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A stationary base plate, a chain drum locking mechanism and a reducer mechanism are provided for a manual rolling door operator, in which the reducer mechanism has an output shaft and the chain drum locking mechanism has a chain drum, a wedge wheel, a drive shaft, a plurality of moving rollers, and fixed rods. If the chain drum is rotated in any direction by a force pulling a chain run around the chain drum, the fixed rods push against the moving rollers to release a wedging action from the wedge wheel which simultaneously renders the drive shaft to be rotated. However, if the force stop to pull the chain, the wedge wheel locks the moving roller by the wedging action due to the weight of a curtain of slats so as to stop the rotation of the drive shaft.
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RELATED APPLICATION
[0001] This application is a continuation-in-part of and claims the benefit of and priority from U.S. patent application Ser. No. 11/766,643, filed Jun. 21, 2007, entitled MULTIPURPOSE AQUEOUS PARTS WASHER, which is a continuation-in-part of and claims the benefit of and priority from U.S. patent application Ser. No. 11/681,652, filed Mar. 2, 2007, entitled MULTIPURPOSE AQUEOUS PARTS WASHER, which applications are expressly incorporated herein by reference.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates generally to a multipurpose aqueous parts washer used to wash grease, oil, dirt, or other debris from mechanical parts, and more particularly, to a parts washer having a housing with an automatic spray-washing portion, a soak-agitated portion, and a manual sink washing portion for cleaning parts.
BACKGROUND
[0003] The present disclosure relates to an apparatus for washing mechanical parts using a multipurpose aqueous parts washer. Mechanical parts collect dirt, abrasion residue, used grease, or other debris during normal operation. During periodic maintenance, extraordinary maintenance, repairs, or even scheduled upgrades, mechanics disassemble parts from a larger mechanical element, such as a car engine. Individual parts and subassemblies must be washed before they are either thrown away, diagnosed, or eventually reinstalled in the mechanical device or before they are reconditioned for further use.
[0004] A parts washer is an apparatus that cleans parts, either individually or in groups of parts, including but not limited to machinery and machine parts. Parts washers can also clean elements such as chains, tools, or other elements susceptible to contact with greased or oiled parts. These cabinet-size devices are an essential tool for any mechanic or other worker having to clean parts in a workshop. For example, automobile mechanics place parts washers alongside tools or next to their work area.
[0005] The core technology associated with parts washers is not unlike the technology associated with the cleaning of kitchen utensils and other food preparation accessories, the significant difference being that mechanical parts washer residue must be controlled before the effluents are released into the environment. Therefore, a different cleaning solutions must often be used, parts are generally washed infrequently once dirt is dried, oil-based effluents must be collected and confined, insoluble debris must be collected and filtered as sludge, and cleaning solutions are regenerated. The workshop environment in which the parts washers are used also differs. Some parts washers use an aqueous cleaning solution to dissolve and remove grease, carbon, resins, tar, inks, and other debris. These parts washers use water, soap, and/or detergents, common or proprietary. Other more aggressive parts washers use hydrocarbon-based solvents or other solvents to degrease and wash parts. This disclosure contemplates a parts washer using any type of cleaning solution, but more preferably, a parts washer using an aqueous-based cleaning solution.
[0006] Parts washers are generally stored where parts are removed or processed for convenient use. Confined spaces and other constraints associated with workshops warrant compact and portable devices. Parts washers must also be robust and durable under strenuous environments. Four different technologies are know in the industry: manual parts washing, automatic parts washing, spray spray-under immersion cleaning, and soaked parts washing. Manual parts washers generally resemble a sink positioned over a reservoir holding a cleaning fluid. An operator of the manual parts washer may push a pedal or take another action to activate a pump and heating element located within the reservoir to circulate cleaning fluid. The advantages of manual parts washers are numerous. For instance, they allow for tactile recognition of fine layers of dirt, the focus of cleaning efforts at a specific location, and cleaning conducted immediately by the operator.
[0007] Automatic parts washers normally consist of a housing holding some basket for storage and removal of parts within the housing. Automatic devices have large access doors, a control apparatus for programming spraying cycles, and pumps/heaters for activating the cleaning solution within the device. The advantages of automatic parts washers over manual parts washers includes time saving, the capacity to store dirty parts within the enclosure between washes, parts washing during off-hours, the capacity to utilize pressures and temperatures outside of the human comfort zones, and most importantly, the reduction of the need for the operator to dirty his hands during the washing operation. Other technologies used to wash parts include soaking and agitating, where parts are immersed in a volume placed within a constant, regenerated flow of cleaning solution or with a series of immersed sprays within the regenerated flow or placed in a cross flow of cleaning solution. These washers allow for the slow removal of attached dirt by using a relatively low quantity of cleaning fluid.
[0008] Each of these different technologies has distinct advantages and disadvantages. Different washers are currently needed if different advantages are desired since the management of parts, cleaning solutions, debris, and sludge differs greatly between these devices. What is needed is a device capable of offering the advantages associated with each of these technologies within a single apparatus capable of handling the constraints associated with these types of washers. What is also needed is a series of operative and functional improvements associated with the use of a single device with multiple washing solutions.
SUMMARY
[0009] One aspect of the present disclosure relates generally to a multipurpose parts washer used to remove grease, oil, and dirt from mechanical parts, and more particularly, to an apparatus for washing parts within a single housing having an automatic cleaning portion, with a first cleaning chamber for spraying parts, a second cleaning chamber for soaking or agitating parts, and a manual cleaning portion. The multipurpose parts washer may include three cleaning portions, all portions provided cleaning solution by a single pump, a reservoir portion to collect and store an important volume of cleaning solution and debris from the washing process, a single controller interface operated from a display, and a thermal energy source for healing the cleaning solution. The multipurpose design may also include other novel features such as the use of a submerged pump within the reservoir, easy-access panels for the pump motor, the controller, and the display, an integrated sink serving as a safety lid of the automatic portion to collect the cleaning solution of the manual cleaning portion and to enclose the automatic cleaning portion, and the use of a timer and a multicolor display for easy operation of each of the cleaning portions. The design may also include a concurrent multifunction cleaning feature, a thermally activated safety lid, an immersion agitation tank, and a removable flat or V-shaped debris pan.
[0010] The multipurpose design may also include a dynamic spray bar in the agitation tank for improved cleaning during agitation, and a spay distribution system and associated spray bars capable of rotational adjustment and pivot to direct the sprays to a desired portion of the first cleaning chamber and allowing better access to the reservoir portion and other cleaning equipment located within the automatic cleaning portion of the apparatus for washing parts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The following disclosure as a whole may be best understood by reference to the provided detailed description when read in conjunction with the accompanying drawings, drawing description, summary, abstract, background of the disclosure, field of the disclosure, and associated headings. Identical reference numerals when found on different figures identify the same elements or a functionally equivalent element. The elements listed in the summary and abstract are not referenced but nevertheless refer by association to the elements of the detailed description and associated disclosure.
[0012] FIG. 1 is a partly exploded perspective view of the multipurpose aqueous parts washer in accordance with an embodiment of the present disclosure with the manual cleaning portion in an open configuration and where the pull-out rack is shown partially removed.
[0013] FIG. 2 is a perspective view of the multipurpose aqueous parts washer of FIG. 1 without the pull-out rack with internal portions shown by transparency and with cleaning solution within the agitation tank.
[0014] FIG. 3 is a perspective view of the multipurpose aqueous parts washer of FIG. 1 with the manual cleaning portion in a closed configuration.
[0015] FIG. 4 is a side elevation of the multipurpose aqueous parts washer of FIG. 1 in the configuration and as shown in FIG. 2 along line 4 - 4 .
[0016] FIG. 5 is a side elevation of the multipurpose aqueous parts washer of FIG. 1 in the configuration and as shown in FIG. 2 along line 5 - 5 .
[0017] FIG. 6 is a top view of the multipurpose aqueous parts washer of FIG. 1 in an open configuration.
[0018] FIG. 7 is a schematic representation of the different elements within the multipurpose aqueous parts washer of FIG. 1 in the closed configuration.
[0019] FIG. 8 is a back perspective view of the multipurpose aqueous parts washer as shown in FIG. 1 in an open configuration with the safety lid closed with shadow view of the elements located within the basin.
[0020] FIG. 9 is a back perspective view of the multipurpose aqueous parts washer of FIG. 8 without the shadow view.
[0021] FIG. 10 is a side elevation of the multipurpose aqueous parts washer of FIG. 1 in the configuration and as shown in FIG. 3 along line 4 - 4 with a V-shaped debris pan.
[0022] FIG. 11 is a schematic representation of the different elements within the multipurpose aqueous parts washer of FIG. 1 in the closed configuration equipped with a V-shaped pan.
[0023] FIG. 12 is a top view of another embodiment of the multipurpose aqueous parts washer of FIG. 1 in an open configuration with spray bars rotatably connected to the distribution bar.
[0024] FIG. 13 is a side elevation of the multipurpose aqueous parts washer shown in FIG. 4 with spray bars rotatably connected to the distribution bar.
[0025] FIG. 14 is a schematic representation of the different elements within the multipurpose aqueous parts washer of FIG. 4 in the closed configuration.
[0026] FIG. 15 is a schematic representation of the spray portion of the first cleaning chamber where the sprays are directed to the center of the spray portion according to another embodiment of the present disclosure.
[0027] FIG. 16 is a schematic representation of the spray portion of the first cleaning chamber where the sprays are directed to the bottom of the spray portion according to another embodiment of the present disclosure.
[0028] FIG. 17 is a schematic representation of a possible flexible collar and clips for the rotatable connection of a spray bar to a distribution bar according to another embodiment of the present disclosure.
[0029] FIG. 18 is a perspective view of the multipurpose aqueous parts washer of FIG. 1 without the pull-out rack with internal portions shown by transparency with a pivoting spray bar according to another embodiment of the present invention.
[0030] FIG. 19 is a side elevation of the multipurpose aqueous parts washer of FIG. 1 in the configuration and as shown in FIG. 18 along line 19 - 19 .
[0031] FIG. 20 is a side elevation of the multipurpose aqueous parts washer of FIG. 1 in the configuration and as shown in FIG. 18 along line 20 - 20 .
[0032] FIG. 21 is a top view of the multipurpose aqueous parts washer of FIG. 1 in the configuration and as shown in FIG. 18 in an open configuration.
[0033] FIG. 22 is a schematic representation of the different elements within the multipurpose aqueous parts washer of FIG. 1 in the configuration and as shown in FIG. 18 in the closed configuration.
DETAILED DESCRIPTION
[0034] FIG. 1 is a partly exploded perspective view of the multipurpose aqueous parts washer in accordance with one embodiment of the present disclosure with a manual cleaning portion in an open configuration and where a pull-out rack is shown partially removed. FIG. 1 shows an apparatus for washing parts 1 having an automatic cleaning portion 2 defined by a first cleaning chamber 102 and a second cleaning chamber 101 . The apparatus for washing parts 1 in one embodiment includes a manual cleaning portion 103 movably connected to the automatic cleaning portion 2 by a series of pivoting points 23 .
[0035] The apparatus for washing parts 1 in one embodiment includes two different washing chambers 101 , 102 and a cleaning portion 103 that can each be operated by an operator when faced with different washing needs. Each chamber or portion 101 , 102 , and 103 preferably shares a cleaning solution 100 common to each chamber or portion 101 , 102 , and 103 and collected in a single reservoir portion 36 . It is understood by one of ordinary skill in the art that while three distinct chambers or portions 101 , 102 , 103 are shown in a certain spatial distribution, chambers and portions may be arranged in any spatial configuration. For example, one of ordinary skill in the art recognizes that while the apparatus for washing parts 1 is shown as a vertically stacked cabinet in a shape close to that of a shop tool box, the apparatus for washing parts 1 can be placed in numerous other locations having different spatial constraints, including but not limited to the need to attach the device to a ceiling, a top ledge, a bottom ledge, or installed in a countertop or work benches, or inserted in a portion of a vehicle, inside a sliding or rotating door, on a tool storage device, or even outside of a maintenance vehicle. For each of these and other uses, the displacement and reorientation of the chambers and portion 101 , 102 , and 103 may be used in a wide variety of possible configurations that do not alter this disclosure.
[0036] Users can use the apparatus for washing parts 1 to wash a single piece or numerous pieces in one of the portions 101 , 102 , 103 . In another embodiment, numerous parts can be washed simultaneously in the different portions 101 , 102 , 103 . A method is contemplated for washing a plurality of parts using an apparatus for washing parts 1 where in a first step, a first part to be washed is placed inside an automatic cleaning portion 2 , a second part is then placed inside an agitation tank such as the second cleaning chamber 101 . The cleaning portion 103 is then closed before placing a third part to be washed in the manual cleaning portion 103 . Finally, in the method, a pump 79 is activated as described hereafter to wash the first, second, and third parts placed in different cleaning portions 101 , 102 , 103 . In another embodiment, the pump 79 is activated only after at least two parts are placed in at least two different cleaning portions 101 , 102 , 103 .
[0037] Use of different sizes and geometries of each chamber or portion 101 , 102 , and 103 based on the different needs in the marketplace associated with a particular model of apparatus for washing parts 1 is also contemplated. As an example related to the embodiment shown in FIGS. 1-8 , if this disclosure is adapted to the undercarriage of a moving maintenance vehicle of a speed car crew having specific needs for soaked washing of large parts, a larger second chamber 101 may be placed along the side the first chamber 102 of equivalent size and shape as the first chamber, and the manual cleaning portion 103 can be located above one or both of the chambers 101 , 102 .
[0038] In one embodiment shown in FIG. 1 , the manual cleaning portion 103 is defined by a basin 104 shown in FIG. 7 preferably made of a folded or bent sheet of metal 106 , which is best illustrated in FIG. 5 , having a resistant polymer or vinyl coating 105 placed above the sheet of metal 106 . In one embodiment, for easy removal and replacement, the polymer coating 105 is not attached to the sheet of metal 106 but is held in place around the edges and drain 46 . It is understood by one of ordinary skill in the art is that the coating 105 above the sheet of metal 106 serves as a mechanical protector and chemical protector, the coating 105 can be removed or replaced by any other suitable laminated protector, including but not limited to paint, surface coating, or even the removal of the polymer coating 105 and replaced by a sheet of metal 106 having a surface like polished glass. It is also understood by one of ordinary skill in the art is the use of any other type of protector designed to withstand the shocks associated from placing parts to be washed within the basin 104 and capable of chemically withstanding any abrasion, corrosion, or degradation associated with the cleaning solution 100 used in the apparatus 1 .
[0039] In one embodiment, the sheet of metal 106 may be made of a plate 47 folded in an open U shape or a V shape with gently sloping side walls placed in opposition to V-shaped end walls 45 to collect the effluents by gravity within the basin 104 . The basin 104 may also include a series of inwardly rolled lips 129 placed on the external periphery of the basin 104 to limit and control splashing. While inwardly rolled lips 129 are shown, any geometry on the outer periphery of the basin 104 or the use of a guard, splashguard, or protection locked into place to offer any similar protection to the operator may be used. Mats, tissues, or other materials at the bottom of the sink 104 that are designed to prevent splashing may also be used.
[0040] FIG. 3 illustrates a bottom drain 46 on the bottom part of the sheet of metal 106 . The drain 46 allows for the transfer of a cleaning solution 100 sprayed within the basin 104 and collection through the drain 46 down into the first cleaning chamber 102 . A cleaning fluid 100 used in the apparatus 1 is released by a fluid distribution device 49 manually operated directly or with the help of tools and gloves by an operator. FIGS. 3 and 8 show a bottom drain 46 having a first possible center strain 110 . FIGS. 1-2 and 4 - 5 show the lower side of the bottom drain 46 . A anti-backsplash plate 17 shown in one disclosed embodiment as a plate attached by a vertical pole at a small distance from the bottom section of the drain 46 . The anti-backsplash plate 17 serves to prevent the cleaning fluid 100 from passing from the first cleaning chamber 102 to the basin 104 . While one type of device is shown having an anti-backsplash plate 17 , the use of any flow displacement system capable of preventing the cleaning fluid 100 from moving up back to the basin 104 during operation of the first cleaning chamber 101 is contemplated.
[0041] In another embodiment, the bottom surface of the basin 104 forms a lid 106 to close the first cleaning chamber 102 when the lid 106 is disposed in a closed position as shown in FIG. 3 . The lid 106 can also rotate via a pivoting point 23 to an open position as shown in FIG. 1 to allow access into the first cleaning chamber 102 . In one embodiment, the basin 104 may be held in the open configuration by two lateral pistons 31 made of two interconnected sections attached on the external surface of the automatic cleaning area 2 and the basin 104 . FIG. 1 shows the pistons 31 in an extended position, whereas FIG. 3 shows the pistons 31 in a retracted position. One of ordinary skill in the art understands that while one type of holding device is shown, any locking or nonlocking holding device capable of operating the basin 104 between an open position and a closed position shown in FIGS. 1 and 3 , respectively, may be used.
[0042] FIG. 1 also shows a locking device 13 on the automatic cleaning area 2 operating in tandem with element 30 as shown on FIG. 1 to lock the basin 104 serving as a lid 106 into the closed configuration as shown in FIG. 3 . A mechanical proximity detector (not shown) operating with or without a counterpart surface allows the control system (described fully hereinafter) to recognize if the lid 106 is open, closed, or ajar. In one embodiment, the detector is part of the locking device 13 . In one contemplated embodiment, the control system turns off any operating cycle or flow from the pump 79 to prevent any spraying or splashing of the operator with cleaning solution 100 if the lid 106 is in the open position. One of ordinary skill in the art recognizes that while one type of proximity detector is placed within the locking device 13 , any type of proximity sensor is contemplated, including but not limited to a bending detector placed within the hinges 23 in the back of the lid 106 , a laser detector, a surface detector placed on the top of the automatic cleaning portion 2 , a mechanical detector where an insert on the bottom surface of the lid 106 enters the first cleaning chamber 102 , or the like. The use of any other type of locking mechanism 13 , 30 designed to secure the basin 104 onto the automatic cleaning area 2 in any potential configuration of basin 104 , lid 106 , or automatic cleaning area 2 is also contemplated, including but not limited to a locking mechanism within the two lateral pistons 31 .
[0043] In one embodiment, FIG. 1 shows an apparatus having a wall protection plate 4 designed to house the basin 104 when in open configuration but also to hold different tools and useful items when the operator is washing parts in the manual cleaning portion 103 . Use of a series of hooks 21 , 22 , lamps 20 , board holders 19 , or net holders 128 placed on the front face 24 of the wall protection plate 4 is contemplated. The object of the different components placed upon the wall protection plate 4 is to provide ease of use and operation to an operator of the apparatus 1 during the different phases of operation. FIG. 1 shows a wall protection plate 4 attached 15 on both sides of the automatic cleaning area 2 . In another embodiment shown in FIGS. 3-4 , the wall protection plate 4 includes locking mechanism 416 such as a hole capable of receiving a second end or in one embodiment a hook 415 or a latch 414 . The latch 414 is also attached at a first end to a safety lid 412 as shown in FIGS. 5 and 9 . The safety lid 412 is pivotally attached 413 to a top section of the manual cleaning portion 103 . The safety lid can be placed an open configuration for access to the work area as shown in FIG. 5 and a closed configuration for restricting access to the work area as shown in FIG. 8 . In FIG. 5 , the safety lid is held in the open configuration by a latch 414 where a thermally activated fusible link 411 is capable of releasing the safety lid 412 from the open configuration to the closed configuration when the fusible link 411 is thermally activated. One of ordinary skill recognizes that the safety system is designed to function when in the presence of fire or heat located within the apparatus 1 , to allow for the heat to rise to the fusible link 411 calibrated in such a way and at such a melting point to close the safety lid 412 on the manual cleaning portion 103 . The safety lid as shown is capable of limiting the supply of oxygen to fuel combustion within the apparatus 1 . This described feature is called an active safety device, which improves safety conditions of the apparatus 1 in the event of unsafe operating conditions. The active safety device uses gravity as the motor force to move the safety lid 412 from the open configuration to the closed configuration. Use of any active safety device implemented in conjunction with apparatus is contemplated, such as the use of other devices or systems that modify the configuration of the apparatus 1 , including but not limited to a foaming system or a chemical release system capable of changing the conditions and returning the device to safe conditions. FIG. 5 shows a fire-activated fusible link 411 connected to one end of the latch and to an inside surface of the safety lid 412 . The use of any locking mechanism to be used in conjunction with the second end of the latch 414 is also contemplated, such as a magnet, a clamp, a tab, or a spring.
[0044] FIG. 5 also shows the use of rollers 11 or wheels placed under the automatic cleaning area 2 to provide the apparatus 1 with horizontal mobility. Use of manually locking wheels or coasters to stabilize the apparatus 1 at a specific location is contemplated but not shown. Use of stabilizing weights for counter-balance or to reduce any ensuing waves created within the reservoir portion 36 in the cleaning solution 100 by moving elements placed within the automatic cleaning area 2 is also contemplated but not shown. Other vibration-reducing techniques, such as the use of ballasts (not shown) within the reservoir portion 36 , are equally contemplated and disclosed herein to reduce movement caused within the reservoir portion 36 due to moving elements or pumping effects 79 during the rotation of an internal moving element.
[0045] Holding and storage surfaces 111 as shown in FIG. 4 are use within the basin 104 to aid an operator and allow for flow of cleaning solution 100 from the parts once the parts washed and placed on the storage surfaces 111 . In one embodiment, the storage surface 111 is made of perforated metal and is attached to the V-shaped end walls 45 . While one possible type of storage surface 111 is shown, any type of ledge, ridge, pole, axis, support, or the like capable of serving as a resting place for parts washed in the basin 104 may be used. The basin 104 further comprises a handle 18 or a grasping mechanism designed to allow the operator to move the basin 104 from a first configuration to a second configuration (both configurations shown in FIGS. 1 and 3 ). The basin 104 as shown on the left and right side elevation views of FIGS. 4-5 has a front angle 50 forming a higher back wall than a front wall where the handle 18 is located in the front of the basin 104 . One of ordinary skill in the art recognizes that such geometric constructions, such as those shown in the disclosed possible embodiments, are functionally useful but in no way limit the scope of what is contemplated and can be adapted based on functional requirements of any specific type of apparatus for washing parts 1 .
[0046] In one possible embodiment, the fluid distribution device 49 located in the basin 104 is supported on the bottom side of the basin 104 by a U-shaped connector 25 on a hose as shown in FIG. 1 . The hose is, in one embodiment, split into two parallel sections 54 , 107 , each including a manual control valve 51 , 52 upstream of the sections 54 , 107 , respectively, each having downstream a manual cleaning tool such as a quick-connect hose 48 or a flow-thru brush 43 designed with a brush ending 42 . The manual cleaning portion 103 is operated by an operator by placing a mechanical part to be washed inside of the basin 104 and then holding with a hand either one of the sections 54 , 107 and the associated manual cleaning tool and opening the manual control valve 51 , 52 associated with the section 54 , 107 held by the operator to direct the flow of cleaning solution 100 onto the part. The manual control valve 51 , 52 as shown is a manually activated flow regulator. While manual control valves 51 , 52 are shown, any flow control device, either manual or electronically controlled to maintain the flow at appropriate speeds and pressures for parts washing, may be used. The use of pulsating flow is also contemplated.
[0047] FIG. 2 shows in partially transparent view the first cleaning chamber 102 having a spray portion 108 located above a reservoir portion 36 . The reservoir portion 36 is configured to store and collect a cleaning solution 100 and collect debris. The spray portion includes a parts support 41 shown in FIG. 7 and a spray bar 38 shown with at least one orifice 37 for distributing the cleaning solution 100 on the parts (not shown). The spray bar 38 as shown in FIG. 2 is shaped with a top level 26 and a bottom level 40 each having orifices 37 oriented toward the central portion of the spray portion 108 to spray any parts placed within the portion. The spray bar 38 also includes a vertical section situated between the top level 26 and the bottom level 40 .
[0048] A secondary bar is shown in FIG. 2 as a possible configuration of orifice 37 distribution. FIG. 7 shows small jets of cleaning solution 100 as dashed lines emanating from both the bottom level 40 and the top level 26 onto the spray portion 108 . FIG. 7 illustrates the pull-out rack 7 shown in perspective view in FIG. 1 in the form of a rack 3 with handles 16 with edges 35 placed in the spray portion 108 and having a center grid-like mesh 34 . A part placed within the spray portion 108 is sprayed by cleaning solution 100 from the top and the bottom. The spray bar 38 includes a first portion disposed adjacent to the parts support and the bottom level 40 and a second portion disposed adjacent to a top end and the top level 26 of the spray portion 108 .
[0049] In an alternate embodiment shown in FIGS. 12-17 , the spray bar 38 is a spray bar system 304 with at least one spray bar either on the top level 26 or the bottom level 40 where at least one spray bar is rotatably connected to a distribution bar 305 . The distribution bar 305 includes a top portion connected to the spray bar of the top level 26 , and a bottom portion connected to at least one spray bar of the bottom level 40 . FIG. 17 shows a close-up view of a flexible collar 95 and two clips 98 each made in the preferred embodiment of metal strips 96 with openings where a screw is rotated 99 to tighten the strip from the position shown by the left clip to the position shown in the right clip. The flexible collar 95 can be made of any semi-rigid material such as high pressure hose or thick sheeting capable of withstanding internal pressure within the spray bar system 304 and any corrosion from the cleaning solution 100 .
[0050] FIG. 15 shows a possible configuration where the two top level spray bars 26 and the two bottom level spray bars 40 are each directed and attached via a section of flexible collar 95 as shown on FIG. 17 to spray the center of the figure identified by reference letter A. For example, if a large piece is placed within the rack 3 , on a parts support 41 , the configuration shown in FIG. 15 allows the top level spray bars 26 to direct the cleaning solution 100 on the upper portion of the part. FIG. 16 shows how each of the four bars 26 , 40 , can be rotated to create a spray 94 that is more directed to the bottom portion of the figure identified by reference letter B. The second configuration can be used for example if only small chains are placed in the rack 3 . The distribution bar 305 can include as shown a top portion and a bottom portion, each connected to the top level spray bars 26 and the bottom level spray bars 40 respectively. As shown by the dashed lines, each of the spray bars 26 , 40 can include at least one orifice 37 for distributing the cleaning solution 100 onto the parts.
[0051] In a preferred embodiment, spay bars 26 , 40 are rotatably connected to the distribution bar 305 either by an union (not shown) or a flexible collar as shown on FIG. 17 . An union is a mechanical connector, generally with threads that locks into place either by screwing a pipe in place or other attachment mechanism. Any connection that may be secured in place by an operator during periodic changes or maintenance may be used.
[0052] In another embodiment shown in FIGS. 18 to 22 , instead of using flexible collars 95 , the bottom level spray bars 40 as shown in dashed lines pivot 342 around a bottom portion pivotally connected to the first spray bar 40 for lifting the spray bar from an operating position to the top position as illustrated by the arrow. The pump 79 can also be connected directly to the distribution bar 305 via a connector 341 .
[0053] The advantages of these different embodiments where either part of the distribution system is moved as shown in FIGS. 18-22 , or redirected as shown on FIGS. 12-17 , include the capacity to provide better access to the inside second cleaning chamber 102 , reduce the pressure drop associated with the different elements within the system in order to increase the exit pressure at the different orifices 37 , and help with the access to the different internal elements such as the rack 3 .
[0054] In one embodiment shown in FIG. 7 , the first cleaning chamber 102 includes a debris collection pan 420 disposed between the spray portion 108 and the reservoir portion 36 . The debris collection pan 420 includes a bottom panel with a plurality of apertures. In one embodiment, the pan 420 is made of metal and has a flat bottom plate. In another embodiment shown in FIGS. 10-11 , the debris collection pan 420 has a V-shaped bottom plate and is equipped with handles 421 . In a preferred embodiment, the bottom is made of 1/16″ thick perforated sheet of metal punched into a V shape at its center. Perforation may be used to provide visual guidance to operators when filling the reservoir portion 36 with cleaning solution 100 . An operator would fill the reservoir portion 36 until cleaning solution 100 can be seen at the low end of the pan 420 indicating that the entire volume under the pan 420 is filled with cleaning fluid. In another embodiment, an operator is guided through the steps of filling the reservoir portion 36 by a visual mark made on the internal surface of the reservoir portion 36 . While two different configurations of debris pans 420 are shown in FIGS. 4 , 7 , and 10 - 11 , different debris collection volumes made of any material capable of storing debris within the environment of the first cleaning chamber 102 are contemplated.
[0055] In yet another embodiment, the perforated plate and side edges are in removable contact with the first cleaning chamber 102 as shown in FIG. 7 . One of ordinary skill in the art recognizes that debris collection below the first cleaning chamber 102 can be made in a plurality of ways using pans of a plurality of techniques in a plurality of shapes with different meshes, materials, and fixation methods. The debris collection pan 420 must be capable of allowing for the cleaning solution 100 to pass unobstructed from the spray portion 108 to the reservoir portion 36 even if debris is positioned on the bottom panel of the pan 420 . Cleaning the pan 420 can be done using a plurality of techniques and methods, such as manual removal of the pan 420 when the device is open from the top and insertion of a sliding door on the external shell of the cleaning chamber 102 to allow for lateral evacuation of the pan 420 . Handles to hold and remove the pan 420 are also contemplated.
[0056] Orifices, pipes, and supports of different sizes, configurations, and orientations enable parts to be adequately washed based on the washing conditions, such as but not limited to temperature, pressure, flow, and diluting capacity of the cleaning solution 100 . Grates may also be fixed directly to the side walls within the spray portion 108 to for horizontal support and to hold parts in the apparatus 1 . One of ordinary skill in the recognizes that while a rectangular geometry of the spray portion 108 is shown, the spray portion 108 may be of any geometry. Hooks, cables, rails, edges, or plates may also be used to hold parts within the apparatus 1 or to hold other parts or racks.
[0057] The second cleaning chamber 101 in one embodiment may be an agitation tank of rectangular geometry designed to hold mechanical parts to be washed in an agitated flow of cleaning solution 100 . In one contemplated embodiment, a series of sprays operating in the cleaning solution 100 can be added to provide additional washing within the agitation tank as shown at FIG. 22 . In one embodiment, the spray the agitation tank 101 is configured to store and collect a portion of the cleaning solution 100 and includes a agitation bar 343 connected to the pump 341 with at least one orifice for distributing the cleaning solution dynamically within the agitation tank. A valve 342 can be connected inline between the agitation tank 101 and the pump 341 to control the flow of the cleaning solution through the agitation bar 343 into the agitation tank 101 . What is shown is one possible way to use the cleaning solution 100 to provide dynamic washing to any part (not shown) placed within the agitation tank 101 without having the need for manual cleaning.
[0058] A connector 39 shown in FIG. 2 is in fluid communication with the spray bar 38 and allows for a flow of cleaning solution 100 to the bottom of the agitation tank. The agitation tank includes a top opening and a bottom inlet 427 for circulation of the cleaning solution 100 from the bottom inlet 427 of the agitation tank up to the top of the agitation tank and through the top opening. In one embodiment, a notch is shown to guide the flow through the top opening, but one of ordinary skill understands that overflow over the top opening is also contemplated. A three-way valve with a first opening is connected to the bottom inlet 427 , a second opening is connected to the spray bar, and a third opening is in communication with the first cleaning chamber 102 . The three-way valve can also include a manual selector having a first orientation where the first and second openings are in fluidic communication to circulate the cleaning solution in the agitation tank and a second orientation where the first and third openings are in fluidic communication to drain the cleaning solution 100 from the agitation tank into the first cleaning chamber 102 .
[0059] In one embodiment, the flow is continuous and allows for surface regeneration of the cleaning solution 100 within the agitation tank by creating a constant overflow of the cleaning solution 100 back into the reservoir portion 36 in order to dilute any suspended particles of debris in the cleaning solution 100 . One of ordinary skill in the art will recognize that other methods are contemplated to conduct flow regeneration within the second cleaning chamber 101 such as a drain valve at the bottom of the agitation tank, a pressure-sensitive control flow valve acting as a bottom drain calibrated to maintain the level of cleaning fluid 100 within the agitation tank, the use of a removable container such as a basket or the like for pouring the cleaning solution back into the reservoir portion 36 . A notch 247 as shown on FIG. 2 can be used to facilitate the flow from the second cleaning chamber 101 to the first cleaning chamber 102 .
[0060] The second cleaning chamber 101 as shown is placed adjacent to the first cleaning chamber 102 with a top opening in communication with the top surface of the automatic cleaning portion 2 . This allows easy access by an operator simply by placing the lid 106 in the open configuration by holding the handle 18 and accessing both the first cleaning chamber 102 and the second cleaning chamber 101 . While one possible method of access is shown, placement of the second cleaning chamber 101 may be at any judicious position within the automatic cleaning portion 2 , including but not limited to the placement within a rack, a protuberance, an enclosure, or other bodies that may be placed in fluid communication with the first cleaning chamber 102 . Use of baskets, slow-acting brushes, or other moving parts to improve the cleaning capacity of the agitation tank is also contemplated. Other means of cleaning within the second cleaning chamber are contemplated, including but not limited to ultrasonic cleaning. FIG. 1 also discloses the use of a bottom drain 12 used to drain the reservoir section 36 during maintenance.
[0061] The apparatus for washing parts 1 further includes a thermal energy source 120 having an element section 56 and a control section 121 disposed in the reservoir portion 36 contiguous with the cleaning solution 100 for controlling the temperature of the cleaning solution 100 . Because a single cleaning solution 100 is used throughout the apparatus for washing parts 1 , the cleaning solution 100 is heated to operating temperatures by a single element section 56 located in the reservoir portion 36 . In one embodiment, the fluid is heated to a range of 120° F. to 125° F. FIG. 8 shows the use of a back door 9 attached using a fixation means 10 such as screws or bolts to provide access to the control section 121 of the thermal energy source 120 . FIG. 6 shows the compartment 80 created to house the control section 121 of the thermal energy source 120 . In yet another embodiment, a thermal energy source 120 made of a single block can be placed within the reservoir portion 36 to heat the cleaning solution 100 locally or in a close proximity to the inlet of the pump 79 . In this embodiment, the reservoir portion 36 can be increased in size by removing the compartment 80 . The use of a thermal junction having leak-proof seals between the compartment 80 and the reservoir portion 36 is not disclosed but is known by one of ordinary skill in the art. In one embodiment, heat is activated and controlled by placing the surface temperature of the element section 56 in close proximity to the equilibrium temperature of the cleaning solution 100 .
[0062] A thermal sensor (not shown) placed in communication with the cleaning solution 100 is used to regulate the temperature of the cleaning solution 100 by alternatively energizing and turning off the thermal energy source 120 . In yet another embodiment, the regulation of the temperature is selected the operator on the display 6 using a temperature selection knob (not shown). While one possible temperature control device is shown, any method of thermal regulation of the cleaning solution 100 either in a single source, a diffuse source, or a plurality of sources may be used. Calibration of the heating source 120 to other operating and equilibrium temperatures based on the optimal temperature of the cleaning solution 100 is also contemplated. Two different energy sources may also be used, the first to heat the cleaning solution 100 to a first operating temperature based on the optimal operating temperature during a manual washing operation and a second to heat the cleaning solution locally before it is sprayed onto parts located within the spray portion 108 . In one embodiment, an inclined wall is placed on the separation wall between the compartment 80 and the reservoir portion 36 .
[0063] The apparatus for washing parts 1 also includes a pump 79 placed in fluid communication with the cleaning fluid 100 in the reservoir portion 36 . FIG. 5 shows the pump 79 as having a fixation plate 71 and a motor 70 for energizing the pump 79 . In one embodiment, the pump 79 is disposed in the reservoir portion 36 and is in fluid communication with the spray bar 38 , the agitation tank 101 , and the fluid distribution device 49 for circulating the cleaning solution 100 from the reservoir portion 36 to at least one of the agitation tank 101 , the fluid distribution device 49 , or the spray bar 38 . The pump motor 70 is placed in an enclosure 125 protected by a side door 124 as shown in FIG. 8 . The pump 79 pushes cleaning fluid 100 to the other sections of the apparatus for washing parts 1 . In one embodiment, the reservoir portion 36 has a capacity of up to 20 gallons.
[0064] The apparatus for washing parts 1 also includes a control system 200 for controlling the device described above, and more specifically, an automatic cleaning portion 2 defined by a first cleaning chamber 102 including a spray portion 108 and a reservoir portion 36 , the spray portion 38 having a parts support 41 , and a spray bar 38 with at least one orifice for distributing a cleaning solution 100 onto the parts (not shown), the reservoir portion 36 configured to store and collect the cleaning solution 100 . The manual cleaning portion 103 is movably connected via a pivoting point 23 to the automatic cleaning portion 2 and is defined by a basin 104 including a drain 46 and a fluid distribution device 49 , wherein the fluid distribution device 49 discharges the cleaning solution 100 into the basin 104 for collection through the drain 46 into the first cleaning chamber 102 , and a plug 5 adapted for electrical connection 27 to an external power supply for energizing a controller 201 for selectively activating at least a timer 7 in the automatic cleaning portion 2 , a proximity detector (not shown) between the automatic cleaning portion 2 and the manual cleaning portion 103 , a thermal energy source 56 in contact with the cleaning fluid 100 in the reservoir portion 36 , a pump 79 disposed in the reservoir portion 36 in fluidic communication with the spray bar 38 and the fluid distribution device 49 for circulating the cleaning solution 100 from the reservoir portion 36 to at least one of the fluid distribution device 49 or the spray bar 38 . The controller 201 further energizes a first display 32 when the pump 79 is energized, energizes a second display 124 when the cleaning fluid falls below a fixed level in the reservoir portion 36 , and a third display 123 when the thermal energy source 56 energizes the cleaning solution 100 .
[0065] A control system 200 energized by an energy input device is disclosed having a plug 5 having an electrical connection 27 of with a ground wire (three-ended plug). Grounding of the device and the use of a plug 5 having an electrical connection 27 without a ground wire is also contemplated. The plug 5 can be rolled up around a support 130 , shown in FIG. 8 . In one embodiment, a water level detector 77 having a water detector 78 is connected to the control system 200 . The level detector 77 serves to prevent the pump 79 from being damaged by overheating when running in air rather than submerged within cleaning solution 100 . In one alternate embodiment, the level detector as shown is connected directly to the pump 79 .
[0066] In one embodiment, the control system 200 is operated by the operator via a display 6 where a green light is the first display 127 with a rotating on/off switch, the second display 32 is an orange light for monitoring the heating element, and the third display 123 is a red light for monitoring the water level. In one embodiment, the user turns the timer 7 clockwise for a desired duration of time. In another embodiment, the timer 7 is set to one-quarter hour. The use of a Ground Fault Circuit Interrupter (GFCI) breaker 8 placed under a protection plate and within the display 6 is also shown. This breaker allows users to reset the device in case of interruption of the process, such as, but not limited to the malfunction of a component or the failure of the level detector 77 to detect cleaning solution 100 in the reservoir portion 36 or a short circuit.
[0067] Persons of ordinary skill in the art appreciate that although the teachings of the disclosure have been illustrated in connection with certain embodiments, there is no intent to limit the invention to such embodiments. On the contrary, the intention of this application is to cover all modifications and embodiments falling fairly within the scope of the teachings of the disclosure.
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The present disclosure relates generally to a multipurpose parts washer used to remove grease, oil, and dirt from mechanical parts, and more particularly, to an apparatus for washing parts within a single housing having an automatic cleaning portion, with a first cleaning chamber for spraying parts, a second cleaning chamber for soaking and agitating parts, and a manual cleaning portion. The multipurpose design also includes novel features such as the use of a submerged pump within the reservoir, easy-access panels for the pump motor, the controller, and the display, an integrated sink serving as a safety lid of the automatic portion to collect the cleaning solution of the manual cleaning portion and to enclose the automatic cleaning portion, and the use of a timer and a multicolor display for easy operation of each of the cleaning portions. The design may also include a concurrent multifunction cleaning feature, a thermally activated safety lid, an immersion agitation tank, and a removable flat or V-shaped debris pan. The multipurpose design may also include a dynamic spray bar in the agitation tank for improved cleaning during agitation, and a spay distribution system and associated spray bars capable of rotational adjustment and pivot to direct the sprays to a desired portion of the first cleaning chamber and allowing better access to the reservoir portion and other cleaning equipment located within the automatic cleaning portion of the apparatus for washing parts.
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PRIORITY CLAIM
[0001] The present Application claim priority of U.S. provisional application No. 60/323,399 filed Sep. 19, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to suppression of fire by extremely fine droplet water mist and more particularly, but not by way of limitation, to an improved method and apparatus for producing an extremely fine sub-micron size water mist using an electronic ultrasonic device that produces the mist at ambient-pressure and delivering the mist for application in suppressing fire.
[0004] 2. Description of the Prior Art
[0005] Water based fire suppression systems have been in existence for many years. However, such systems were mostly replaced and the technology forgotten because of the advent of halon gas systems in the 1960's. In recent years, it has been discovered that halon gas is not environmentally safe, and its continued use has been banned due to its alleged potential to deplete ozone in the atmosphere. Thus, there is an urgent need for an alternative fire suppression system, which is effective and environmentally friendly and safe to use.
[0006] Because of several favorable properties, water mist has been reconsidered as a potential agent to replace halon gas. Water is environmentally friendly with no known toxic properties. Water has a specific heat of 4.18 J/g, and a high latent heat of vaporization of 2260 J/g that assist in cooling a flame. Finally, water is readily available and cost efficient.
[0007] Water mist suppresses fire through different mechanisms. Each mechanism exhibits a different degree of influence on the overall suppression efficiency of a water mist. The four important operating mechanisms are heat extraction, oxygen displacement, radiant heat attenuation, and dilution of the vapor/air mixture. Heat extraction and cooling of the flame has the maximum effect on the efficiency of fire suppression and the other mechanisms usually supplement the heat extraction mechanism. The inventors have found through computer simulation and experimentation that the success of water mist in its application to fire suppression depends on the ability to produce nearly nanometer-scale and sub-micron size droplets of water mist and deliver the mist to various fire scenarios. Extremely small droplets vaporize instantaneously and absorb energy to extract heat from the flame. Water mist droplets of larger diameters vaporize more slowly and are not as efficient in suppressing fires. Also, larger droplets are not as easily entrained into the fire and need additional momentum if the mist has to be introduced away from the firebase.
[0008] An extremely small amount of water is needed for suppressing a fire using extremely small sub-micron droplet mist because of considerable volume expansion accompanied by the transition from liquid state to mist (about 1700 times). This water expansion is based on the ratio of the density of liquid water and the gas-like nanoscale mist.
[0009] An extremely fine mist of sub-micron size water droplets avoids several of the disadvantages normally associated with the conventional water mist fire suppression technology. For instance, typical water mist applications having larger droplet size may cause a kinetic effect on flames causing flare-up from the water droplets striking the fuel surface. Further, because of slower vaporization and greater momentum needed, larger droplets wet surfaces within the area of application, conduct electricity and often damage items. Thus, a key to the success of water mist technology is the use of very fine nanometer-scale sub-micron water mist produced using a cost-effective and ambient-pressure method.
[0010] Previously, fine water mist production for fire suppression has been an expensive technology in terms of installation and maintenance. These prior art systems have included one or more expensive components such as high pressure storage of fluids, conduit pipes often under high pressure, and pumps providing pressurized fluid to specialized atomizer nozzles. Besides the expense of the components these components and conduit piping require valuable space for installation. Space may be limited for certain applications such as marine vessels, machine space, and computer data centers.
[0011] In addition to the expense of installing known water mist fire suppression systems, these systems present safety and mechanical concerns. In particular, pressurized systems are subject to leaks and hazards of bursting posed by retaining fluids under pressure. These systems require nozzles that are subject to clogging because of the small nozzle diameters and are also expensive and difficult to construct because of their precise specifications.
[0012] Even with state-of-the-art mechanical atomizers, the droplet size obtainable in these prior art systems is on the order of 50-200 microns. For many applications, these droplets are effective in cooling the flame. However, the water mist droplets may still wet surfaces and cause electrical conductance. This limits the ability to use water mist fire suppression in computer and data center applications or in precious item preservation rooms in libraries and museums. Moreover, the mechanical atomization technology required by conventional fine water mist fire suppression systems is still very expensive.
[0013] The prior art mist generation methods for fire suppression involve well-documented methods such as pressurized water or twin-fluid atomizers. Single fluid pressure based atomizers use water stored or pumped at high pressure (40 to 200 bar) and spray nozzles with relatively small orifice sizes. Twin-fluid systems use air, nitrogen, or other gases to atomize water at a nozzle. Although rare, there are some references to utilization of extremely high (hypersonic velocity) gas streams to generate ultrasonic waves to generate mist for suppressing fires and explosions. For instance, U.S. Pat. No. 4,378,851 to Egbert deVries describes ultrasonic nozzles of a general type in which a gas orifice penetrates a liquid filming surface. The method uses a high velocity gas stream to shear the thin layer of liquid and atomizing it. Others, U.S. Pat. Nos. 5,211,336 and 5,323,861, teach a method of producing a mist using a compressed air stream, and U.S. Pat. No. 5,597,044 teaches using a carrier gas having supersonic velocity. All the prior methods use either pressurized water or compressed gas as means of atomizing water to produce a water mist. As a result, these prior technologies produce atomized water mist using mechanical means that are not user friendly and are not very economical for generating water mist for fire suppression.
[0014] Thus, an objective of this invention is to provide a water mist fire suppression method using an electronic ultrasonic device to produce a water mist having sub-micron diameter water droplets.
[0015] Another objective of the invention is to provide a fire suppression device using an electronic ultrasonic device to produce a water mist and optionally powered by line fed electric power or a portable power source such as a battery.
[0016] Another objective of the invention is to provide a fire suppression method using a mist generation method that does not need pressurized water or gas.
[0017] Another objective of the invention is to use a method of generating mist for fire suppression that does not use an atomizing nozzle and is free from nozzle clogging and flow blockage.
[0018] Another objective is to provide a device and method to deliver a sub-micron diameter mist to a fire such that the mist that is entrained by the fire.
[0019] Another objective is to provide a mist for fire suppression without mechanically imparting excessive momentum to the mist.
[0020] Another objective is to provide a mist for fire suppression in which the mist is introduced from the base of the fire.
[0021] Another objective is to minimize water usage and the quantity of mist needed to suppress a fire by delivering the mist to the most reactive zone in the fire base using very low injection velocity.
[0022] Another objective is to reduce the quantity of water needed for suppressing a fire by several orders of magnitude compared to conventional mists by using water mist having submicron diameter droplets.
[0023] Another objective is to deliver a sub-micron mist to a fire such that the mist will vaporize before impact with surface areas and not wet surface areas or equipment.
[0024] Another objective is to provide a tangential flow of air or gas for carrying the mist out of the mist generator without affecting the centerline mist producing water fountain.
SUMMARY OF THE INVENTION
[0025] This invention relates to a fire suppression method based on water mist generated by an electronic high frequency ultrasonic device and differs from prior methods of producing water mist using high-pressure elements or high velocity gas streams. More specifically, the present invention discloses the application of a mist generation method that does not use nozzles to create an ultra fine mist, and, thus, is free of nozzle clogging and does not require water at elevated pressure or compressed gas. The advantageous features of the invention positively enhance the safety and economics of fire protection and suppression, while improving effectiveness.
[0026] In the present method, a water-bed at ambient pressure is subjected to ultrasonic waves driven by a piezoelectric transducer. The oscillating frequency of the transducer provides the ultrasonic waves that atomize the water to produce droplets less than 1 micron in diameter, for instance 500 nanometers. Typical transducers available commercially are used in medical applications, cleaning, and humidifying and operate with oscillating frequencies up to 2.4 MHz. These transducers produce extremely small droplets, which could measure less than 1 micron with some modification of the design. For generating largely sub-micron size mist, as required in the present invention, these transducers may be modified and adapted to provide still higher oscillating frequencies.
[0027] In addition to increasing the frequency of the transducer, there are other factors that can be varied to decrease the droplet size of the resulting water mist, such as by reducing the surface tension of the water and increasing the water-bath temperature or both. The sensible enthalpy increase due to elevated water-bath temperature is not significant compared to the large magnitude of latent heat of vaporization of water. Based on this, increasing the bath temperature is an efficient way of reducing the mist droplet size. In fact, the natural heating taking place during the oscillator functioning helps to achieve this beneficial property.
[0028] The sub-micron diameter water mist droplets created by the invention are created at ambient pressure. Therefore, the mist is created cost effectively because no expensive technology is required, and the mist also is created very safely and quietly. Instead of using noisy and dangerous high-pressure equipment, the water mist is produced by ultrasonic oscillations provided by electronic means without need for pressurized fluids or sophisticated nozzles.
[0029] The very fine mist generated by the ultrasonic waves is transported and delivered to a fire by gravity, a carrier gas comprised of inert gas, or air. Using air, the mist could also be pulled out of the generator using a fan at the outlet without using any additional carrier fluids. Each of the preferred delivery methods avoid the problems associated with excess momentum that exist in prior art mist delivery systems using high velocity nozzles and the like.
[0030] The specific embodiments of the apparatus and delivery method utilized in the invention may vary in accordance with the particular fire suppression application chosen. Proposed application areas include computer data storage areas, machinery space, ground vehicles, aircrafts, ships and submarines, a variety of indoor fires, and a variety of outdoor fires. Special cases may involve application for wildfires, such as in forests, where mist curtains may be installed at calculated distances to absorb the heat energy and diffuse the thermal wave propagation. These various application areas may be treated using fixed systems, hand-held portable devices, or indoor-outdoor portable units. Regardless, each specific system should be designed utilizing the present method of generating a water mist and having a suitable delivery setup for the specific fire scenario.
[0031] Because the sub-micron diameter droplets are so fine, the droplets do not wet surface areas when applied to a fire. Instead, the droplets rapidly vaporize to cool and suppress the fire. Likewise, the droplets will not come to rest on items and cause electrical conduction or damage precious items. With these advantages of the invention in mind, the method and apparatus for generation of a sub-micron droplet mist for application in fire suppression has the potential to replace halon and other chemicals presently used in place of halons for fire suppression.
[0032] Ultrasonic atomizers consisting of an oscillator and atomization needle, or probe, combination are alternatives to demonstrate the concept of producing mist and are commercially available. However, these atomizers are not cost-effective and would be prohibitively expensive for use in fire suppression. The oscillator and needle combination uses similar principles as described herein, but these available atomizers have low throughput and are specifically designed for low momentum coating or spraying applications. In these, the liquid travels through a probe through a narrow bore and spreads out as a thin film on the atomizing surface. The oscillations at the tip of the probe discharge the liquid into micro-droplets, and then eject them to form a gentle, low viscosity mist. The liquid viscosity may be a limiting factor, and the commercial ultrasonic atomizers of this type are expensive and cannot be widely used for large-scale applications such as fire suppression or protection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in conjunction with the accompanying drawings in which:
[0034] [0034]FIG. 1 is a schematic elevation view of an exemplary water mist generator for fire suppression showing the ultrasonic device generated nanometer-size water mist system of the present invention.
[0035] [0035]FIG. 2 is a schematic elevation view of a fire suppression device using an electronic ultrasonic device to generate a nanometer-size water mist.
[0036] [0036]FIG. 3 is a schematic of top view of flow velocity vectors at the fan or gas ingress and mist egress planes.
DETAILED DESCRIPTION OF THE INVENTION
[0037] Referring to the figures, the present invention is shown in alternative embodiments. In particular the figures illustrate two embodiments of a device having a mist generator 8 for producing an ultra fine mist having sub-micron droplets. The embodiments disclose various ways of delivering the mist to a fire consistent with application of the present invention to various fire scenarios.
[0038] As shown in FIG. 1, a piezoelectric transducer 10 connected to a suitable power source via connections 12 is submerged in a bath of water or arranged in physical communication with water 14 . The piezoelectric transducer 10 receives an electrical signal and converts electrical oscillations into high frequency mechanical vibrations, which facilitate atomization of fluids by producing ultrasonic pressure or sound waves with rarefaction and compression cycles. The required high frequency pressure waves may be provided by a high frequency wave generating laser device also. Above a certain limit, rarefaction produces cavitations resulting in bubbles that expand during the negative pressure excursion and implode violently during the positive excursion. The cavitations cause the imploding bubbles to surface out as small droplets during compression and form a fog-like mist. Therefore, the ultrasonic waves produced by the high frequency vibration cause atomization of the water into a cloud of droplets.
[0039] Above the oscillating disc of the transducer 10 , a water fountain plume 16 is formed with heights varying from a few inches to a foot depending on the oscillator size and frequency. Extremely small droplets of water 18 or mist originate and come out of this fountain 16 . Attempts to suppress this fountain 16 or block the flow results in either the termination or reduction of mist 18 throughput. As a result, if a fan is used to push the mist out of the generator container 8 , the air-flow will have the tendency to disturb the fountain flow. Flow behaviors at the entrance into the flow ingress 20 of the mist generator 8 and leaving at the mist egress 22 should be well organized as shown in FIG. 3. To optimize the function of the invention, well-organized flow behavior will typically be a feature of the invention discussed further herein.
[0040] The water droplet 18 size produced by the atomization process depends on the surface tension of the water 14 , the density of the water, and the frequency of oscillation of the transducer 10 . The droplet 18 diameter decreases with decreasing surface tension of the liquid 14 . The droplet 18 size also decreases with increasing liquid 14 temperature. Also, droplet 18 diameter decreases with increasing density of liquid 14 and frequency of oscillation of transducer 10 . In order to produce a mist 18 having a significant proportion of droplets having droplet diameters less than one micron as recommended by the invention, the frequency produced by the piezoelectric transducer 10 herein may be greater than usual. The approximately 1 to 2 MHz frequencies used in prior functions is adequate for producing mists having 1-10 micron particles useful in humidifiers, foggers, cleaning, and other functions. However, frequencies greater than 2.5 MHz may be necessary in certain cases to produce the sub-micron particle mists 18 useful in the fire suppression method taught by the invention, and some modification to present commercial transducers may be required unless other methods are used as suggested above to decrease the mist droplet 18 diameter produced. A variable frequency oscillator may be utilized to obtain a broader spectrum of droplet 18 size.
[0041] As indicated before, smaller diameter droplets 18 can be produced by decreasing the surface tension of the water 14 , which may be accomplished by adding surfactants or surface-active agents or by some other means. In addition, the temperature of the water 14 may be elevated to decrease the droplet 18 diameter produced. During the process of oscillations and sound wave propagation some heating takes place, which promotes the further reduction of droplet 18 size.
[0042] The cloud-like collection of extremely small droplets 18 forming the mist created by the atomizing process hang in the air like a dense gas and slowly succumb to the forces of gravity without any other impetus provided. The impetus provided and, therefore, the mist delivery method used in the invention is an important factor in the effectiveness of the mist 18 in fire suppression because the mist 18 should be supplied to the firebase. Therefore, the delivery method used by the invention is customized according to the particular fire suppression application, such as open fires, room fires, machinery space, or other scenarios. The delivery of the mist 18 may vary with respect to direction, throughput, momentum imparted to the mist 18 , the composition of carrier gas that may be used, and the mist concentration in the mass flow. The mist generating devices 8 in the figures show representative delivery outlets 22 and 24 .
[0043] The delivery direction of the mist 18 may be manipulated by the location of outlets 22 and 24 and the application of a fan or other device to direct the exiting mist 18 . In some fire suppression applications, the mist 18 will exit the generator 8 and be gravity fed to a fire and self-entrained. While in other applications, the mist 18 will need to be transported to a fire by a propellant carrier inert gas, such as nitrogen or carbon dioxide. Or, the mist 18 may be transported by air using a fan to push the mist 18 toward the firebase and create a suitable flow using the optimum velocity of the diverging airjet. The proportion of mist 18 to carrier gas or air has to be properly manipulated for sufficient mist ratio to successfully suppress the fire, and the throughput of the mist 18 must be sufficient to suppress a fire.
[0044] Balancing the momentum of the mist delivery is an important feature of the present method. The mist momentum should be low enough that a fire can self-entrain the mist 18 as the mist 18 is delivered to an area surrounding the application. The injection momentum of the mist 18 should be just enough to reach the firebase. If the mist momentum is too high, the cold mist 18 will not be entrained by the fire's buoyancy force and will not be effective in suppression. If the mist momentum is insufficient, the mist 18 may not reach the vicinity of fire and be entrained into the firebase.
[0045] A schematic of an embodiment of the mist generation unit 8 illustrating the invention is shown in FIG. 2 customized to provide a suitable flow of mist 18 for some fire suppression applications. A first bottom section of the unit 8 provides a power supply section 26 . This section contains a power-utility box 28 including 48 V step-down transformer. The power box 28 and transformer is operably connected to a transducer 10 contained within an second section, referred to herein as the mist generation section 30 .
[0046] In the embodiment shown in FIG. 2, the transducer 10 is submerged in a water bath 14 . The mist generation section 30 may include an ingress inlet 32 and egress outlet 34 to provide water to create a water reservoir 14 . In some applications, a sensor 36 may be provided as shown in this second section 30 to monitor the level of the water reservoir 14 , and a system may be provided for controlling the inlet 32 and outlet 34 of the water reservoir 14 to adjust the water level accordingly.
[0047] A mist egress or mist outlet section 40 is situated above or near the mist generation section 30 , and an air or carrier gas flow ingress section 38 is situated above or near the mist egress section 40 . Alternatively, the relative positions of mist egress section 40 and gas flow ingress section 38 can be interchanged, namely, the mist egress section 40 can be above the gas flow ingress section 38 . The mist 18 either flows out of the unit as a result of gravity or may be pushed by a secondary force. A fan may be provided to communicate with the mist outlet section 40 via the flow ingress section 38 and direct the mist 18 through the egress spout 22 at the desire momentum and proper air to mist mix. Alternatively, a compressed inert gas or compressed air may be arranged to communicate with the mist egress section 40 via a conduit of the flow ingress section 38 such as the inlet spout, represented by the ingress inlet 20 .
[0048] Whether a fan or compressed air or any gas is used to direct the mist 18 to the firebase in the present invention, the flow 42 of carrier medium through the mist generator 8 has to be well organized to avoid disturbing the water fountain 16 extending upward from the water bath or reservoir 14 as discussed above. One way to avoid flow 42 disturbing the fountain 16 is to keep the ingress inlet 20 and egress outlet 22 for gas and fluid flow 42 tangential to the container 8 as shown in FIG. 3. In the embodiment shown, the flow 42 of gas and fluid circulates peripherally of the water fountain 16 , while the center of the mist generator 8 where the water fountain 16 exists is relatively quiet. Assuming the fountain 16 is at the center of the water bath 14 , the flow 42 of gas and fluid will not affect the flow of the water fountain 16 producing the mist 18 . FIG. 3 shows the flow vectors 42 along the side of the cylindrical container 8 and finally pushing the mist 18 out of the container 8 at the selected outlet 22 location.
[0049] A rectangular geometry does not accommodate well the type of tangential wall-side flow 42 shown in FIG. 3. Therefore, the generator unit 8 should preferably have a cylindrical geometry as shown in FIG. 3 rather than rectangular. However, other variations may be beneficial under certain applications with proper care to ensure the water fountain flow 16 is not disturbed by the flow of mist carrier medium. For instance in FIG. 1, a water flow is provided in through an inlet 48 and outlet 50 that communicates with the transducer 10 to produce the mist 18 . The mist 18 flows up from the water fountain 16 and is provide impetus for direction to the firebase by the flow 52 of carrier medium through the flow inlet 54 , which is situated above the water fountain plume 16 so as not to disturb it.
[0050] Some existing high-throughput humidifier designs use a fan to directly push the mist upwards out of the container. As a result of direct air current impinging on the water fountain in these high-throughput humidifiers, the mist coming out of the humidifier contains large proportions of coarse water droplets. This mist containing coarse droplets is not efficient for fire suppression application. Moreover, the fan speed of these commercial humidifiers is not calibrated to transport at least 0.8 to 0.9 mass fraction of mist, and the momentum of mist coming out of commercial humidifier units is not controlled to match a specific fire application. Thus, the commercially available high-throughput humidifiers do not possess the mist throughput and delivery strategies discussed herein and would not be well suited or contemplated for use in fire suppression.
[0051] While a preferred embodiment of the invention is disclosed, various alternatives for configuring the device will be found through development within the scope of the present invention. In particular, the locations of the mist outlet section 40 and carrier gas inlet section 38 may be switched. For example, the carrier gas inlet 38 may be below the mist outlet section 40 .
[0052] The power supply section 26 , mist generation section 30 , and mist outlet section 40 of the mist generation unit 8 are arranged vertically in FIG. 2 and provided a top 44 having a handle 46 . The unit 8 could be arranged having predominately horizontal or vertical construction. An independent portable power source may be added to the mist generation unit 8 configuration in desirable applications. For example, a rechargeable battery may be provided for a portable mist generation unit 8 , such as a hand-held unit, to be used as indoor or outdoor portable fire extinguishers or like those sometimes used in open room fires.
[0053] Adding water-soluble chemical additives to the water bath 14 may enhance the effectiveness of water mist 18 generated by the fire suppression unit. Also, water immiscible liquid additives may be added to the water bath 14 to enhance fire suppression because the cavitations and atomization process will cause the additives to uniformly mix with the water mist 18 generated. Some examples include the formation of macro-emulsions or micro-emulsions containing water and other water immiscible fire extinguishing chemical liquids mixed during ultrasonic oscillations. These mechanical micro-emulsions do not need surfactant chemicals to hold the droplets inside the microstructure, which offers the unique advantage of a hybrid micro-emulsion of a chemical suppression liquid and water to be used as a fluid. The resultant hybrid fluid system provides opportunities such as to reduce the effective weight of water to be carried in aircrafts for in-flight fire situations.
[0054] There are many fire suppression scenarios in which the present method and apparatus may be used effectively. In lieu of an exhaustive list of applications, several exemplary embodiments and scenarios are presented for consideration without intending to exclude other fire suppression applications in which the invention would be useful. First, the invention may be used in portable hand-held fire extinguishers. In these portable hand-held units, the desired water mist 18 may be produced at ambient pressure without storing fluids under pressure. Refilling portable unit could be accomplished using a closable opening to receive tap water from a faucet. Further, the portable unit may be battery operated.
[0055] In a second embodiment, the invention may be used in computer/electronic data storage rooms and electronically sensitive areas. The ultra fine sub-micron water mist 18 generated by the invention is especially advantageous to this application because the water mist 18 will not deposit or accumulate on sensitive electronic equipment. In this embodiment, the water mist 18 may be produced in a container, such as the mist generation unit 8 , and the mist 18 flowing out of the container could be dispersed using a fan or an induced inert gas flow. In fact, for many computer data center rooms, the raised bottom floor structure therein provides a good opportunity to implement the present mist delivery system. Because the air-ducts in these type data centers are in the floor and the flow of air is always upwards, a water mist 18 using the present system can be easily dispersed from the bottom floor. Optionally, a system based upon the invention designed for this environment may be situated in the ceiling work of a room for selective distribution by gravity to be self-entrained by the fire.
[0056] In a third embodiment, the invention may be used in machinery space such as large machinery areas, hangers, turbines, machine shops, or switch rooms. The water mist may be produced by the mist generation unit 8 and delivered to the fire location by fan or induced inert gas flow. Optionally, mist generators could be installed on a floor below the machine area to be self-entrained by a fire easily from below.
[0057] In a fourth embodiment, the invention may be used in ground vehicles, aircraft, ships and submarines. In all of these applications the mist 18 generated may be re-distributed by fans or induced inert gas flow depending upon space designed for. If the area may be totally flooded with the mist 18 and ventilation is secured, then the mist 18 may be gravity fed and entrained by the fire flow field.
[0058] In a fifth embodiment, the invention may be used to suppress open fires. In this scenario, the mist 18 is delivered to the firebase by a directed very low velocityjet having a mist concentration of at least 75-80% of the total mass flow.
[0059] In a sixth embodiment, the present invention may be used to block the propagation of forest fires. A mist curtain of desired thickness or several meters could be created in the direct path of propagation of the fire. The mist curtain would absorb energy from the leading edge of the fire and slows down the fire. By installing several layers of water mist curtains, the fire propagation rate could be considerably decelerated and finally brought to the complete stop.
[0060] In addition to fires, the fine water mist of this invention may be used to mitigate blasts and explosion processes or in humidification. Because of the extremely small droplet size, the mist 18 will absorb considerable energy and, therefore, reduce excessive over-pressures developed during a blast within a blast or explosion area. With regard to humidification, the extremely small droplets vaporize fast and provide cooling as well as the required humidity level in intended areas.
[0061] While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention as defined by the claims.
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An improved method and apparatus for producing an extremely fine micron and sub-micron size water mist using an electronic ultrasonic device that produces the mist at ambient-pressure and delivering the mist for application in suppressing fire. A piezoelectric transducer is arranged to produce a water mist having at least a portion of sub-micron size droplets. The water mist is produced by high frequency pressure waves or ultrasonic waves of predetermined or variable frequency, including frequencies which may exceed 2.5 MHz. The water mist is directed to a firebase to be self-entrained by the fire's flame. The momentum provided the water mist in directing the mist is minimized to enhance the ability of the fire to entrain the mist, and the flow of the carrier medium is usually directed tangentially about the water fountain creating the mist. Further, the throughput and concentration of the mist is controlled to ensure that the entrained mist will be sufficient to cool and suppress the fire. The water mist may be effectively utilized for mitigating blast and reducing over pressures. The fine water mist may also be utilized for humidification because of its fast vaporization and efficient cooling behavior. The apparatus may be modified in its physical design and direction of output, and the method may be modified by adjusting the throughput of mist, composition of mist, concentration of mist, and momentum of mist, whereby fire may be suppressed under many different scenarios.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of and claims benefit under 35 USC §120 to co-pending U.S. patent application Ser. No. 11/172,230 entitled “Fire Resistant Insulator Pad” filed Jun. 30, 2005; and this application is also a Continuation-in-Part of and claims benefit under 35 USC § 120 to co-pending U.S. patent application Ser. No. 11/778,523 entitled “Fire Combustion Modified Batt” filed Jul. 16, 2007, which in turn is a Continuation-in-Part of and claims benefit under 35 USC §120 to U.S. Pat. No. 7,244,322 entitled “Method for Forming Fire Combustion Modified Batt” filed Oct. 18, 2004, which is a Continuation of and claims benefit under 35 USC §120 to U.S. Pat. No. 7,147,734 entitled “Method for Forming Fire Combustion Modified Batt” filed Jan. 7, 2003, which is a national stage (continuation) of and claims benefit under 35 USC 371 to International Patent Application PCT/US01/07831 entitled “Method for Forming Fire Combustion Modified Batt” filed Mar. 13, 2001, which is related to and claims benefit under 35 USC §119 to U.S. Provisional Patent Application Ser. No. 60/188,979 entitled “Bi-lofted Fire Combustion Modified Batt” filed Mar. 13, 2000; all of which are assigned to the Assignee of the present application and hereby incorporated by reference as if reproduced in their entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not applicable.
BACKGROUND
[0004] A mattress typically comprises a mattress core encased in a decorative ticking. The mattress core contains various components such as foam, high-loft and densified nonwoven fiber batts, and springs. The foam and high-loft fiber batts provide softness and comfort for a person sleeping on the mattress, while the springs and densified fiber batts provide firmness and support for the person sleeping on the mattress. In order to keep the springs from penetrating the other layers of the mattress core, a densified fiber batt, known as an insulator pad, is positioned between the springs and the other mattress core components. The insulator pad is sufficiently dense such that it cannot be penetrated by the wire that makes up the mattress springs.
[0005] In recognition of the dangers associated with mattress fires, mattress manufacturers have recently begun designing fire resistant (FR) mattresses. Mattress fires are dangerous because the combustible mattress core components (i.e. the foam and fiber batts) burn rapidly when ignited. The heat from the fire also heats the compressed mattress springs, causing them to expand. As the mattress fire consumes the insulator pad, the insulator pad weakens and is unable to maintain the separation between the springs and the other combustible mattress core components. Consequently, the springs penetrate the insulator pad and push the mattress core components into the fire, infusing the fire with fresh fuel. Because the springs are wound in a helical pattern with air in the center, when the springs expand into the fire, they also infuse the fire with fresh oxygen. The combination of flammable fabrics, foams, and compressed mattress springs make mattress fires one of the most dangerous types of household fires. Realizing the magnitude of the danger associated with mattress fires, almost every mattress manufacturer in the United States has developed, or is developing, mattresses incorporating FR materials.
[0006] An important part of an FR mattress design is the location of the layer of FR material (the FR layer) within the mattress. Existing FR mattress designs locate the FR layer at or near the surface of the mattress. For example, some products incorporate the FR layer into the mattress ticking, while other products position the FR layer directly underneath the mattress ticking. The fundamental concept behind these products is the creation of a FR layer between the fire and most or all of the combustible mattress components, thereby separating the fire from a potential fuel source.
[0007] Locating the FR layer at or near the surface of the mattress limits the effectiveness of the FR layer. Being located at or near the surface of the mattress, the FR layer is limited to soft and flexible materials because the use of hard or rigid materials at or near the surface of the mattress makes the mattress uncomfortable to sleep on. In order for the FR layer to be soft and flexible, however, the structural integrity of the FR layer must be decreased. The decrease in structural integrity makes the FR layer susceptible to fracture or breakage, particularly during a fire. If the FR layer fractures or breaks during a fire, the FR layer is no longer able to maintain the separation between the fire and the combustible mattress core components. Without this separation, the fire consumes the insulator pad and other combustible mattress core components and heats the compressed mattress springs causing them to expand and penetrate the insulator pad, the mattress core components, and the FR layer, further propagating the mattress fire. Thus, the failure of any part of the FR layer eventually leads to propagation of the mattress fire as if there were no FR layer. The FR characteristics of the mattress would be improved if there were a secondary FR layer within the mattress such that failure of a part of the primary surface FR layer would not allow the springs to propagate the fire. Consequently, a need exists for an apparatus that maintains the separation of the mattress springs and the flammable mattress core components during a fire.
SUMMARY OF THE INVENTION
[0008] In one aspect, in invention is an apparatus comprising a core; and a ticking surround the core; the core comprising a spring assembly; a flammable core component positioned above the spring assembly; and a fire resistant (FR) insulator pad positioned between the spring assembly and the flammable core component. In embodiments, the FR insulator pad comprises a plurality of inherently FR fibers, the FR fibers are oxidized polyacrylonitrile, the FR fibers are modacrylic fibers, and/or the FR fibers are non-inherently FR fibers treated with an FR chemical compound. Variously, the weight per unit area in ounces per square foot of the FR insulator pad is greater than twice the thickness in inches of the FR insulator pad and/or the FR insulator pad is comprised of a blend of a plurality of inherently FR fibers and a plurality of shoddy fibers which are not inherently FR. In another embodiment, the invention includes a mattress comprising the aforementioned apparatus.
[0009] In another aspect, the invention is a mattress core comprising a spring assembly having an upper surface; a fire resistant (FR) insulator pad having an upper surface and a lower surface, the lower surface of the FR Insulator pad positioned adjacent to the upper surface of the spring assembly; and a cushioning layer having a lower surface positioned adjacent to the upper surface of the FR Insulator pad; wherein the FR Insulator pad protects the cushioning layer by delaying the penetration of the cushioning layer by the spring assembly during a partial or complete consumption of the core by a fire. In an embodiment, the weight per unit area in ounces per square foot of the FR insulator pad is greater than twice the thickness in inches of the FR insulator pad. Variously, the FR Insulator pad comprises a plurality of inherently FR fibers, the FR insulator pad is comprised of a blend of a plurality of inherently FR fibers and a plurality of shoddy fibers which are not inherently FR, the FR fibers are oxidized polyacrylonitrile, the FR fibers are modacrylic fibers, and/or the FR fibers are fibers treated with an FR chemical compound. In another embodiment, the invention includes a mattress comprising the aforementioned apparatus.
[0010] In yet another aspect, the invention is a bedding product comprising a core; a ticking enclosing the core; the core comprising a first core component located within the ticking; a second core component located within the ticking, the second core component capable of penetrating the first core component in the absence of an insulator pad therebetween; a fire resistant (FR) barrier located within the ticking, the FR barrier physically isolating the first core component from the second core component by preventing the second core component from penetrating the first core component; wherein the FR barrier delays penetration of the first core component by the second core component during a partial or complete consumption of the bedding product by a fire. In embodiments, the barrier comprises a plurality of inherently FR fibers, the FR fibers are oxidized polyacrylonitrile, the FR fibers are modacrylic fibers, and/or the FR fibers are fibers treated with an FR chemical compound. In embodiments, the barrier is comprised of a blend of a plurality of inherently FR fibers and a plurality of shoddy fibers which are not inherently FR, and/or the invention includes a mattress comprising the aforementioned apparatus. In another mattress embodiment, the weight per unit area in ounces per square foot of the FR barrier is greater than twice the thickness in inches of the FR barrier.
[0011] In a final aspect, the invention is a densified nonwoven fiber batt comprising a plurality of shoddy fibers; a plurality of FR fibers blended with the shoddy fibers to form a homogenous fiber blend; and a resin intermixed with the homogenous fiber blend, the resin bonding the shoddy fibers to other shoddy fibers and to the FR fibers, the resin also bonding the FR fibers to other FR fibers and the shoddy fibers; wherein the weight per unit area in ounces per square foot of the nonwoven fiber batt is greater than twice the thickness in inches of the nonwoven fiber batt. In an embodiment, the FR fibers are selected from the group consisting of: oxidized polyacrylonitrile fibers, modacrylic fibers, and fibers treated with an FR chemical compound. In another embodiment, the invention includes a mattress comprising the aforementioned nonwoven fiber batt.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a more complete understanding of the present invention, and for further details and advantages thereof, reference is now made to the accompanying drawings, in which:
[0013] FIG. 1 is a perspective view of an embodiment of the FR Insulator Pad;
[0014] FIG. 2 is a section view of an example of a mattress incorporating the FR Insulator Pad;
[0015] FIG. 3 is a section view of an example of a mattress foundation incorporating the FR Insulator Pad;
[0016] FIG. 4 is a block diagram of one method for manufacturing the fiber batt embodiment of the FR Insulator Pad;
[0017] FIG. 5 is a plan view of an embodiment of an apparatus for manufacturing the fiber batt embodiment of the FR Insulator Pad in accordance with the method of FIG. 4 ;
[0018] FIG. 6A is a side view of an embodiment of a thermal bonding apparatus used in forming the shoddy batt embodiment of the FR Insulator Pad in accordance with the method of FIG. 4 ; and
[0019] FIG. 6B is a side view of an alternative embodiment of a thermal bonding apparatus used in forming the shoddy batt embodiment of the FR Insulator Pad in accordance with the method of FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
[0020] The FR Insulator Pad will now be described in greater detail. As seen in FIG. 1 , one embodiment of the FR Insulator Pad 40 is a densified nonwoven fiber batt comprising a plurality of carrier fibers and a plurality of FR fibers. The carrier fibers and the FR fibers are blended together into a homogeneous fiber blend prior to being formed into the FR Insulator Pad 40 . While the fiber blend can be any of a number of suitable blends, in one embodiment, the carrier fibers can be anywhere in the range of about 5 percent to about 95 percent by volume of the blend with the FR fibers representing the remaining about 95 percent to about 5 percent by volume of the fiber blend. In a preferred embodiment, the fiber blend comprises about 50 percent by volume carrier fibers and about 50 percent by volume of FR fibers. However, the FR Insulator Pad 40 includes numerous possible fiber blend compositions and should not be limited by the specific embodiments discussed herein.
[0021] The carrier fibers are fibers that are not inherently FR nor have been treated to become FR. The carrier fibers may be natural fibers, such as cotton, silk, or wool, synthetic fibers, such as rayon, polyester, polypropylene, polyethylene, and other polymer fibers, recycled fibers, such as shoddy fibers, or combinations thereof. Preferably, the carrier fibers are shoddy fibers, which are fibers recycled from clothing, bedding, fabric, and other natural and synthetic materials. Alternatively, the shoddy materials may be a specific type of recycled fiber, such as polyester or polypropylene from the manufacturing of bedding components or cotton waste from the yarn spinning process. The shoddy material is generally cleaned and shredded to form a homogeneous fiber blend prior to being blended with the FR fibers.
[0022] The FR fibers are fibers that resist burning, impede the propagation of a fire, reduce the ignitability of the volatile gases produced during burning, and/or help to extinguish the fire. The FR fibers may be fibers that are inherently FR, such as charring fibers, or fibers that have been chemically treated to become FR, such as fibers treated with a FR chemical compound. Examples of FR fibers are fully or partially oxidized polyacrylonitriles (O-PAN) such as PYRON® available from Zoltek, FORTAFIL® available from Fortafil Fibers, AVOX™ available from Textron, PANOX available from SGL Technik, THORNEL® available from Amoco Performance Products, and PYROMEX® available from Toho Texax; meta-aramids, such as NOMEX® available from DuPont, TEUINCONEX™ available from Teijin Limited, and FENYLENE™ available from Russian State Complex, including poly(m-phenylene isophthalamide); para-aramids such as KEVLAR® available from DuPont, TECHNORA® available from Teijin Limited, TWARON® available from Teijin Twaron, and FENYLENE™ available from the Russian State Complex, including poly(p-phenylene terephthalamide) and poly(diphenylether para-aramid); melamines such as BASOFIL® available from Basofil Fibers; polybenzimidazole; poly (p-phenylene benzobisoxazoles); polyctherimides; polybenzimidazole such as PBI® by Hoechst Celanese; polyimides such as P-84™ by Inspec Fibers and KAPTON® by DuPont; polyamideimides such as KERMEL® by Kermel; novoloids such as phenol-formaldehyde novolac and KYNOL™ available from Gun Ei Chemical Industry; poly (p-phenylene benzobisoxazole) (PBO) such as ZYLON® available from Toyobo; poly (p-phenylene benzothiazoles) (PBT); polyphenylene sulfide (PPS) such as RYTO® available from Chevron Phillips Chemical, TORAY PPS available from Toray Industries, FORTRON® available from Hoechst Celanese, and PROCON™ available from Toyobo; flame retardant viscose rayons, such as LENZING® FR by Lenzing and VISIL® by Steri Oy; polyetheretherketones (PEEK) such as ZYEX® available from Zyex Ltd.; polyketones (PEK) such as ULTRAPEK™ available from BASF; polyetherimides (PEI) such as ULTEM® available from General Electric; and combinations thereof.
[0023] FR fibers may also be fibers that release oxygen depleting gasses to substantially reduce or eliminate the ignitability of the volatile gases produced during burning and help to extinguish the fire. Examples of these FR fibers are: chloropolymeric fibers, such as those containing polyvinyl chloride (PVC) or polyvinylidene homopolymers and copolymers, such as THERMOVYL™, FIBRAVYL™, RETRACTYL™, and ISOVYL™ available from Rhovyl; PIVIACID™ available from Thueringische; VICLON™ available from Kureha Chemical Industry, TEVIRON® available from Teijin Ltd., ENVILON® available from Toyo Chemical, and VICRON™ made in Korea; SARAN™ available from Pittsfield Weaving, KREHALON™ available from Kureha Chemical Industry, and OMNI-SARAN™ available from Fibrasomni; and modacrylics which are vinyl chloride or vinylidene chloride copolymer variants of acrylonitrile fibers, such as PROTEX® available from Kanegafuchi Chemical and SEF® available from Solutia; and combinations thereof. Further examples of these FR fibers are Fluoropolymeric fibers such as polytetrafluoroethylene (PTFE), such as TEFLON® available from DuPont, LENZING™ available from Lenzing, RASTEX® available from W. R. Gore and Associates, GORE-TEX™ available from W. R. Gore and Associates, PROFILEN® available from Lenzing, and TOYOFLON® available from Toray Industries; poly(ethylene-chlorotrifluoroethylene) (E-CTFE) such as HALAR® available from Ausimont and TOYOFLON® available from Toray Industries, polyvinylidene fluoride (PVDF) such as KYNAR® available from Arkema, and FLORLON™ available from Russian State Complex; polyperfluoroalkoxy (PFA) such as TEFLON® available from DuPont and TOYOFLON® available from Toray Industries, polyfluorinated ethylene-propylene (FEP) such as TEFLON® FEP available from DuPont; and combinations thereof.
[0024] An example of a mattress incorporating the FR Insulator Pad 40 is shown in FIG. 2 . The design and construction of individual mattresses may vary from the example shown in FIG. 2 . The mattress 50 comprises a ticking 51 that surrounds a mattress core made up of a pillow top 52 , comfort layers 54 and 56 , the FR Insulator Pad 40 , spring assembly 58 , and stabilizing layer 59 . The ticking 51 is a decorative fabric that surrounds the mattress core. The pillow top 52 is low density foam or a high-loft nonwoven fiber batt. The comfort layers 54 and 56 are foam or nonwoven fiber batts of various densities. The stabilizing layer 59 is high density foam or a densified nonwoven fiber batt. The spring assembly 58 includes at least one coiled metal wire, most commonly, a compression spring, although other types of springs may be suitable for the purposes contemplated herein, which support the weight of a person sleeping on the mattress. Variously, the plural springs may be unconnected springs residing in a common space and configured for independent movement relative to one another, coupled to another by an interconnecting frame (not shown) and configured for independent movement relative to one another, or coupled to one another by the interconnecting frame and configured for common movement. It is further contemplated that the common space of the spring assembly may be filled with air, loose fibers (also known as fiberfill), fiber batts, or other materials. If material is used to fill the common space, such material may either be flammable or FR. The FR Insulator Pad 40 is positioned adjacent to the upper surface of the spring assembly 58 , between the spring assembly 58 and the combustible mattress core components, which in the example provided herein are comprised of the pillow top 52 and the comfort layers 54 and 56 . If desired, a second FR Insulator Pad 40 may be positioned adjacent to the lower surface of the spring assembly 58 , between the spring assembly 58 and the stabilizing layer 59 . The incorporation of the second FR insulator pad would be advantageous in a mattress design that includes additional combustible mattress core components on the lower side of the spring assembly 58 such that mattress has a mirrored configuration from top to bottom. Such mattresses are considered “flipable” in that they provide the same amount of support to the user regardless of the side of the mattress that the user sleeps on. In either case, the FR Insulator Pad 40 is sufficiently dense to prevent a wire from a spring forming part of the spring assembly 58 from penetrating the FR Insulator Pad 40 and one or more of the combustible mattress core components 52 , 54 , and 56 , all of which are more susceptible to penetration that the FR Insulator Pad 40 .
[0025] An example of a mattress foundation incorporating the FR Insulator Pad 40 is shown in FIG. 3 . The design and construction of individual mattress foundations may vary from the example shown in FIG. 3 . In a typical configuration, the mattress 50 sits atop the mattress foundation 60 . The mattress foundation 60 comprises a ticking 61 that surrounds a mattress foundation core made up of the FR Insulator Pad 40 , spring assembly 62 , and a frame 64 . The ticking 61 is a decorative fabric that surrounds the mattress foundation core. All or part of the mattress foundation 60 may contain mesh netting in lieu of the ticking 61 . The spring assembly 62 includes one or more coiled metal wires, most commonly, compression springs that support the weight of the mattress. The frame 64 is a supporting structure for the spring assembly 62 and is typically made of wood. The FR Insulator Pad 40 is positioned adjacent to the upper surface of the spring assembly 62 between the spring assembly 62 and the ticking 61 . The FR Insulator Pad 40 is sufficiently dense to prevent a wire from a spring forming part of the spring assembly 62 from penetrating the FR Insulator Pad 40 .
[0026] The advantageous properties of the FR Insulator Pad 40 are evident when the mattress 50 or mattress foundation 60 ignites. The function served by conventionally configured insulator pads is to prevent the springs of the spring assembly located on one side of the insulator pad from penetrating through the foam, non-woven fiber batt and/or quilted fiber layers positioned on the other side of the insulator pad. Under normal conditions, a conventionally configured insulator pad would have a sufficient level of mechanical integrity to prevent various components of the spring assembly from penetrating the other layers of the mattress. However, the mechanical integrity of the insulator pad seriously degrades upon the application of flame thereto. Upon loss of mechanical integrity resulting from the combustion of the insulator pad, various components of the spring assembly penetrate through the other layers of the mattress, thereby directly exposing both additional portions of the foam, non-woven fiber batt and/or quilted fiber layers, as well as any combustibles located within the combustible mattress core components 52 , 54 , and 56 , to the flame. In contrast, by using, in accordance with the technology of the present invention, a highly densified FR nonwoven fiber batt to form the FR Insulator Pad 40 , the FR characteristic of the FR Insulator Pad 40 is enhanced relative to that of a conventionally configured insulator pads. As a result, the mechanical integrity of the FR Insulator Pad 40 produced by the use of a highly densified FR nonwoven fiber batt resists weakening upon the application of a flame thereto, thereby preventing or, at a minimum, significantly delaying penetration of the spring assembly through the flammable layers of the mattress which overlie the FR Insulator Pad 40 .
[0027] One method for making the FR Insulator Pad will now be described in greater detail. As seen in FIG. 4 , a method 70 for making the nonwoven fiber batt embodiment of the FR Insulator Pad commences at step 72 when the carrier fibers and FR fibers are blended to form a homogeneous fiber blend. Proceeding on to step 74 , a web is formed from the fibers of the homogeneous fiber blend. At step 76 , the web is coated with a resin, and then the web is subsequently needle punched at step 78 . The web is then compressed in step 80 and heated in step 82 to form a nonwoven fiber batt. The nonwoven fiber batt is subsequently cooled at step 84 and trimmed at step 86 , thereby forming the FR Insulator Pad 40 shown in FIG. 1 . Each of these steps is described in greater detail below.
[0028] Referring now to FIG. 5 , a schematic top plan view of the general processing line 110 for constructing an FR Insulator Pad 40 in accordance with the teachings of the present invention will now be described in greater detail. The general processing line performs steps 72 through 86 of method 70 . As may now be seen, the carrier fibers and FR fibers are blended together per step 72 of method 70 in a fiber blender 112 and conveyed by conveyor pipes 114 to a web forming machine or, in this example, three machines 116 , 117 , and 118 . The fibers are preferably a blend of charring fibers, such as O-PAN, and shoddy fibers but may be a blend of any FR fiber and any carrier fiber. A suitable web forming apparatus is a garnett machine. An air laying machine, known in the trade as a Rando webber, or any other suitable apparatus can also be used to form a web structure. Garnett machines 116 , 117 , and 118 card the blended fibers into a web per step 74 of method 70 , and deliver the web to cross-lappers 116 ′, 117 ′, and 118 ′ to cross-lap the web onto a slat conveyor 120 moving in the machine direction. Cross-lappers 116 ′, 117 ′, and 118 ′ reciprocate back and forth in the cross direction from one side of conveyor 120 to the other side to form a web having multiple thicknesses in a progressive overlapping relationship. The number of layers that make up the web is determined by the speed of the conveyor 120 in relation to the speed at which successive layers of the web are layered on top of each other and the number of cross-lappers 116 ′, 117 ′, and 118 ′. Thus, the number of single layers which make up the web can be increased by slowing the relative speed of the conveyor 120 in relation to the speed at which cross layers are layered, by increasing the number of cross-lappers 116 ′, 117 ′, and 118 ′, or both. Conversely, a fewer number of single layers can be achieved by increasing the relative speed of conveyor 120 to the speed of laying the cross layers, by decreasing the number of cross-lappers 116 ′, 117 ′, and 118 ′, or both. In the present invention, the number of single layers which make up the web of fibers vary depending on the desired fire resistance, density, and thickness of the FR Insulator Pad 40 of the present invention. As a result, the relative speed of the conveyor 120 to the speed at which cross layers are layered and the number of cross-lappers 116 ′, 117 ′, and 118 ′ for forming the web may vary accordingly.
[0029] A heat curable resin is then applied to the web by resin applicator 122 per step 76 of method 70 . There are a variety of techniques suitable for applying resins onto the web. For example, liquid resin may be sprayed or froth resin extruded onto the web. Resins suitable for the present invention are curable by heat and can be any of a variety of compositions. Generally, the resin is comprised of polyvinyl acetate but may also be a polymeric composition such as vinylidene chloride copolymer, latex, acrylic, or any other chemical compound. An example of a suitable resin is the SARAN™ 506 resin available from the Dow Chemical Company. Additionally, the resin can contain antimicrobial, antifungal, or hydrophobic additives that further enhance the properties of the FR Insulator Pad 40 .
[0030] Further describing the application of liquid resin, as the web moves along a conveyor in the machine direction, the resin is sprayed onto the web from one or more spray heads that move in a transverse or cross direction to substantially coat the web. Alternatively, froth resin can be extruded onto the web using a knife or other means. The web can also be fed through or dipped into a resin bath. The applied resin is crushed into the web for saturation therethrough by nip rollers disposed along the transverse direction of the conveyor to apply pressure to the surface of the batt. Alternatively, the resin is crushed into the web by vacuum pressure applied through the batt.
[0031] The web then moves to a needle loom 124 where the web is needle-punched per step 78 of method 70 to increase the density of the web. The needle loom 124 is a device that bonds a nonwoven web by mechanically entangling the fibers within the web. The needle loom 124 contains a needle board (not shown) that contains a plurality of downwardly-facing barbed needles arranged in a non-aligned pattern. The barbs on the needles are arranged such that they capture fibers when the needle is pressed into the web, but do not capture any fibers when the needle is removed from the web. A variety of suitable needles are available from the Foster Needle Company. The use of the needle loom in the present invention provides mechanical compression of the web prior to the application of heat in combination with either vacuum and/or mechanical compression within housing 130 . Of course, it is within the scope of the invention to forego the needle punching step described herein if adequate compression can be obtained by vacuum and/or mechanical compression. Likewise, it is within the scope of the invention to forego the vacuum and/or mechanical compression steps if adequate compression can be obtained by needle punching.
[0032] The conveyor 120 then transports the web to housing 130 for mechanical and/or vacuum compression per step 80 of method 70 and heating per step 82 of method 70 . While there are a variety of resin bonding methods which are suitable for the purposes contemplated herein, one such method the application of vacuum pressure through perforations (not shown) in first and second counter rotating drums 140 and 142 positioned in a central portion of the housing 130 . The first and second counter rotating drums 140 and 142 heat the web to the extent necessary to cure the resin in the web. For example, heating the web to a temperature of 225-275° F. for a period of three to five minutes is suitable for the purposes contemplated herein. Alternatively, the web may instead move through an oven by substantially parallel perforated or mesh wire aprons that mechanically compress the batt and simultaneously cure the resin.
[0033] As the web exits the housing 130 , the web is compressed and cooled per step 84 of method 70 using a pair of substantially parallel wire mesh aprons 170 , only one of which is visible in FIG. 5 . The aprons 170 are mounted for parallel movement relative to each other to facilitate adjustment for a wide range of web thicknesses. The web can be cooled slowly through exposure to ambient temperature air or, in the alternative, ambient temperature air can be forced through the perforations of one apron 170 , through the web and through the perforations of the other apron 172 from FIG. 6A to cool the web and set it in its compressed state. The web is maintained in its compressed form upon cooling since the solidification of the resin bonds the fibers together in that state.
[0034] While there are a variety of resin bonding methods which are suitable for the present invention, one such method, illustrated in FIG. 6A , comprises holding the web by vacuum pressure applied through perforations of first and second counter-rotating drums and heating the web so that the resin in the batt cures to the extent necessary to fuse together the fibers in the web. Alternatively, the web moves through an oven by substantially parallel perforated or mesh wire aprons to cure the resin.
[0035] As may be seen in FIG. 6A , the aforementioned vacuum pressure method may be implemented using counter-rotating drums 140 , 142 having perforations 141 , 143 , respectively, which are positioned in a central portion of a housing 130 . The housing 130 also comprises an air circulation chamber 132 and a furnace 134 in an upper portion and a lower portion, respectively, thereof. The drum 140 is positioned adjacent an inlet 144 though which the web is fed. The web is delivered from the blending and web-forming processes described herein by means of an infeed apron 146 . A suction fan 150 is positioned in communication with the interior of the drum 140 . The lower portion of the circumference of the drum 140 is shielded by a baffle 151 positioned inside the drum 140 such that the suction-creating air flow is forced to enter the drum 140 through the perforations 141 , which are proximate the upper portion of the drum 140 , as the drum 140 rotates.
[0036] The drum 142 is downstream from the drum 140 in the housing 130 . The drums 140 , 142 can be mounted for lateral sliding movement relative to one another to facilitate adjustment for a wide range of batt thicknesses (not shown). The drum 142 includes a suction fan 152 that is positioned in communication with the interior of the drum 142 . The upper portion of the circumference of the drum 142 is shielded by a baffle 153 positioned inside the drum 142 so that the suction-creating air flow is forced to enter the drum 142 through the perforations 143 , which are proximate the lower portion of drum 142 , as the drum 142 rotates.
[0037] The nonwoven web is held in vacuum pressure as it moves from the upper portion of the rotating drum 140 to the lower portion of the counter rotating drum 142 . The furnace 134 heats the air in the housing 130 as it flows from the perforations 141 , 143 to the interior of the drums 140 , 142 , respectively, to cure the resin in the web to the extent necessary to bind together the fibers in the web.
[0038] Referring to FIG. 6B , in an alternative resin bonding process, the web enters housing 130 ′ by a pair of substantially parallel perforated or mesh wire aprons 160 , 162 . The housing 130 ′ comprises an oven 134 ′ that heats the web to cure the resin to the extent necessary to bind the fibers in the web together.
[0039] Collectively referring back to FIGS. 4 , 5 , 6 A and 6 B, the web is compressed and cooled per step 84 of method 70 as it exits from the housing 130 or 130 ′ by a pair of substantially parallel first and second perforated or wire mesh aprons 170 and 172 or 160 and 162 . The aprons 170 and 172 or 160 and 162 are mounted for parallel movement relative to each other to facilitate adjustment for a wide range of web thicknesses (not shown). The web can be cooled slowly through exposure to ambient temperature air or, alternatively, ambient temperature air can be forced through the perforations of one apron, through the web and through the perforations of the other apron to cool the web and set it in its compressed state. The web is maintained in its compressed form upon cooling since the resin bonds the fibers together in the compressed state. The cooled web (which, after completion of the bonding, compression and cooling steps, is referred to as a batt) moves into cutting zone 180 where the lateral edges of the batt are trimmed per step 86 of method 70 to a finished width. The batt is then cut transversely to a desired length to form the FR Insulator Pad 40 .
[0040] It is contemplated that other bonding methods, such as mechanical bonding and thermal bonding, may be used to bond the batt together in lieu of the resin bonding method described herein. Mechanical bonding is the process of bonding the nonwoven batt together without the use of resins, adhesives, or heat. Examples of mechanical bonding methods are needle punching and hydro entanglement. Needle punching is the previously described method of entangling fibers using barbed needles. Hydro entanglement uses streams of high pressure water to entangle the fibers of the nonwoven web. Thermal bonding uses low-melt binder fibers to bind the fibers together. Low-melt binding fibers do not actually melt as the term is generally understood; instead, the low-melt binder fibers become sticky or tacky when heated to a certain temperature. If the fiber batt is to be thermally bonded, the low-melt binder fibers are blended with the carrier fibers and FR fibers to make a homogeneous fiber blend of carrier fibers, FR fibers, and low-melt binder fibers. The fiber blend is then carded into a web as described above. There is no need to apply a resin to the web if the web is to be thermally bonded. The web is then needle punched, if a compression step is desired prior to simultaneous heat and compression. The web is then sent to a compression and heating apparatus, such as those illustrated in FIGS. 6A and 6B , where the heat melts the low-melt binder fibers rather than curing the resin. The batt is then cooled and trimmed in the same way that the resin embodiment of the batt was cooled and trimmed. The FR Insulator Pad 40 includes nonwoven production methods other than the nonwoven production methods described herein and should not be limited to the nonwoven production methods described herein.
[0041] In the embodiment utilizing a nonwoven fiber batt as the FR Insulator Pad 40 , the weight, density, and thickness of the FR Insulator Pad are determined by, among other factors, the process of compressing the batt as it is cooled. The ratio of batt density to batt thickness generally dictates whether the FR Insulator Pad 40 is a high loft batt or a densified batt. For purposes herein, a densified energy absorbing layer has a ratio of weight (in ounces) per square foot to thickness (in inches) greater than about 2 to 1. For example, a fiber batt that is one foot wide, one foot long, one inch thick and has a weight of three ounces is defined herein as a densified fiber batt. In an embodiment, such densified FR Insulator Pads 40 has a density greater than about 1.5 pounds per cubic foot (pcf). Conversely, an FR Insulator Pad 40 having a ratio of weight to thickness of less than about 2 to 1 and/or a density less than about 1.5 pcf are defined herein as high loft batts. For example, a fiber batt that is one foot wide, one foot long, one inch thick and has a weight of one ounce is defined herein as a high loft fiber batt.
[0042] The FR Insulator Pad 40 may also be used for may other applications. For example, the FR Insulator Pad 40 may be incorporated into residential or commercial furniture to maintain the separation between the furniture spring assembly and the other furniture components. The FR Insulator Pad 40 may also be incorporated into vehicle or aircraft seats to maintain the separation between the seat spring assembly and the other seat components.
[0043] While a number of preferred embodiments of the invention have been shown and described herein, modifications thereof may be made by one skilled in the art without departing from the spirit and the teachings of the invention. The embodiments described herein are exemplary only, and are not intended to be limiting. Many variations, combinations, and modifications of the invention disclosed herein are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited by the description set out above, but is defined by the claims which follow, that scope including all equivalents of the subject matter of the claims.
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A mattress or mattress foundation comprising a core and a ticking surrounding the core, the core comprising a spring assembly, a flammable core component positioned above the spring assembly, and a fire resistant (FR) insulator pad positioned between a spring assembly and the flammable core component, wherein the FR Insulator pads protects the flammable core component by delaying the penetration of the flammable core component by the spring assembly during a partial or complete consumption of the mattress or mattress foundation by a fire. The FR insulation pad may be a nonwoven fiber batt comprising a homogeneous blend of shoddy fibers and oxidized polyacrylonitrile fibers. If the mattress or mattress foundation further comprises a surface FR layer, the surface FR layer is the primary FR layer for the mattress or mattress foundation and the FR Insulator pad is the secondary FR layer for the mattress or mattress foundation.
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PRIORITY CLAIM
[0001] This application claims priority of U.S. Provisional Patent Application No. 61/441,107, filed Feb. 9, 2011, the complete disclosure of which is hereby incorporated by reference.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates in general to apparatus for laser-assisted cladding (laser-cladding) of metal surfaces. The invention relates in particular to apparatus for delivering powdered cladding-material onto a surface in the presence of a high-power laser-beam.
DISCUSSION OF BACKGROUND ART
[0003] Laser-cladding has been developed by the laser industry to solve a multitude of industrial applications. Laser-cladding involves directing a high power laser-beam, for example a beam having a total power of several kilowatts (kW) on to a surface to be clad while directing cladding-material in the form of powder into the laser-beam on the surface. The powder melts and hardens to form the cladding. Laser-cladding can be used to repair a worn surface using an identical material; build a layer of different properties onto a base material; or construct an entire near net-shape object directly from powder with specific properties. The powder can be delivered simply by gravity through a suitable nozzle, or entrained in a pressure-fed inert gas. The pressurized gas method lends itself to cladding in other attitudes than the horizontal plane and can even be used to generate three-dimensional shapes.
[0004] A preferred laser-beam source is a two-dimensional array of diode-lasers made by stacking one directional arrays of diode-lasers known in the art as diode-laser bars. Such two dimensional arrays are commercially available with a total delivered power of over 1 kW. Several stacks may be used to provide extra power. FIG. 1 schematically illustrates a modular laser-head assembly 10 arranged for projecting a laser-beam having a rectangular cross-section. Such a unit is available as a HighLight™ D-Series Unit, from Coherent Inc., of Santa Clara, California. Unit 10 includes a bar-stack module 12 which can hold two or more diode-laser bar stacks depending on power required. Attached to module 12 is a collimator optics module 14 including a plurality of inverse Galilean cylindrical lens pairs, arranged to collimate the output of the plurality of diode-laser bar stacks in module 12 in one axis (here the fast-axis) of the diode-laser bars. A condenser optics module 16 includes one or more elements arranged to project the one-axis collimated output into an elongated rectangular beam projection 18 on a working plane at a specified working distance from the condenser optics module. A surface to be clad would be placed in the working plane with provisions for relative motion between the surface and beam-projection 18 to deposit powdered cladding-material onto the surface. The slow-axis and fast-axis of the diode-laser bars are designated arbitrarily herein as the x-axis and y-axis respectively of a Cartesian set, with the beam propagation axis designated as the z-axis.
[0005] In unit 10 , module 12 can be interchanged for a similar module having more or less diode-laser bar stacks for selecting, respectively, more or less total power. Inverse Galilean pairs in module 14 are cartridge-mounted and correspondingly interchangeable to adapt to a particular configuration of module 12 . Elements in module 16 are mounted on a sliding tray 20 , and accordingly are also interchangeable. This interchangeability of modules provides that laser-beam projection 18 can have a wide range of length and width to adapt to various cladding tasks. Powder delivery (cladding) apparatus can be attached to unit 10 via a flange 22 on module 16 . Only sufficient description of unit 10 is provided here for illustrating a laser-beam source which can be used with inventive cladding apparatus described herein. A detailed description of laser-head assembly 10 is provided in U.S. patent application Ser. No. 13/082,171, filed Apr. 7, 2011, assigned to the assignee of the present invention, and the complete disclosure of which is hereby incorporated herein by reference. FIG. 2 schematically illustrates a prior-art powder-delivery (cladding-head) apparatus 30 , suitable for use with a laser-beam-source of which beam source 10 of FIG. 1 is merely one particular example. Such a source is referred to hereinafter as a laser-head. Cladding-head 30 includes a mounting flange 32 having a fixed member 33 attachable to a corresponding flange on a laser head, for example, flange 20 of laser head 10 of FIG. 1 . Flange 32 includes a movable member 34 attached to fixed member 33 and is adjustable in x and y with respect to member 32 by adjusting screws 38 and 40 .
[0006] A four-sided hollow body 36 , open at both ends is suspended from movable member 34 of flange 32 . Attached to opposite sides of body 36 are powder-delivery plates 42 A and 42 B, seen in side-elevation in FIG. 2 . Such plates typically include an internal manifold connection a plurality of channels terminating in a corresponding plurality of orifices at the delivery end of the plates. This detail is not shown in FIG. 2 but is discussed in descriptions of embodiments of the present invention presented further hereinbelow. Powder from a reservoir thereof (not shown) is fed into plates 42 A and 42 B via fixtures 44 A and 44 B, respectively and delivered from the orifices into the vicinity of the laser-beam projection 18 in the working plane. In the drawing of FIG. 2 , the delivery orifices of the delivery plates would be aligned parallel to the x-axis of the laser-beam. The powder is typically entrained in an inert delivery gas, such as nitrogen, at high pressure. The x-y position of the delivery orifices with respect to laser-beam projection 18 is adjustable by adjusting screws 38 or 40 .
[0007] Controlled application of a suitable powder to a interaction point of the laser-beam with substrate material being clad is fundamental to laser-cladding technology. The powder must be precisely placed with respect to the laser energy and the substrate material in order for the process to be successful in producing a high quality, well bonded layer of the desired thickness and shape. The powder delivery nozzle (orifice) configuration has great impact on the clad deposit produced by the process. There are several different configurations of nozzles currently in use. The most common are: arrays of holes (or slots) in a plate for square or line shaped cladding, concentric cones with the powder ejecting from between the gap between the cones, or discrete nozzles singularly or in combination ejecting the powder simultaneously to the laser-beam interaction point for thin line clad deposition.
[0008] In prior-art cladding apparatus the powder distribution shape in these configurations is not able to be changed without removing and replacing the emitting nozzle at best, or completely changing the cladding head at worst. Similarly, the overall size of the deposit is not currently capable of being physically adjusted at the nozzle output other than by injecting more or less powder into the delivery gas stream or using higher or lower delivery gas volume or pressure. Line-shaped clad deposits are desirable for depositing a large amount of material over a large area, be it on flat shapes or round shafts. Square-shaped claddings are desirable for building up thicker layers and controlling the net shape better; and circular shapes are desirable for producing thin lines for the greatest control in applying clad deposits over small features or making 3D near-net shapes. There is a need for a cladding-head that can accommodate the above-discussed variations.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to apparatus for delivering powdered cladding-material into the vicinity of a laser-beam spot defined by a laser-beam projected into a working plane. In one aspect, apparatus in accordance with the present invention comprises a hollow body through which the laser beam is projected onto the working plane. At least a first powder-delivery module removable attached to the hollow body and arranged to receive the powdered cladding-material to be delivered. The powder-delivery module includes one or more nozzles for delivering the received powdered cladding-material into the vicinity of the laser-beam projection in the working plane. The position of the one or more nozzles of the powder delivery module with respect to the laser-beam projection on the working plane is adjustable in x, y, and z Cartesian axes.
[0010] In a preferred embodiment of the inventive apparatus, the powder-delivery module includes a plurality of nozzles for delivering the received powdered cladding-material. The powder delivery module further includes an arrangement for blocking a selected one or more of the nozzles such that only unblocked nozzles deliver the received powdered cladding-material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying drawings, which are incorporated in and constitute a part of the specification, schematically illustrate a preferred embodiment of the present invention, and together with the general description given above and the detailed description of the preferred embodiment given below, serve to explain principles of the present invention.
[0012] FIG. 1 schematically illustrates a prior-art laser head for producing a high power laser-beam suitable for laser-cladding.
[0013] FIG. 2 schematically illustrates a prior-art cladding head for delivering powdered cladding-material into the vicinity of a laser-beam on a surface to be laser-clad.
[0014] FIG. 3 schematically illustrates a preferred embodiment of a cladding head in accordance with the present invention including replaceable powder-delivery plates having an aligned plurality of powder-delivery nozzles with means to adjust the number of nozzles in the aligned plurality thereof through which powdered cladding-material is delivered.
[0015] FIG. 3A schematically illustrates detail of one configuration of the cladding-head of FIG. 3 having two pairs of powder-delivery plates the plurality of nozzles in each pair thereof aligned parallel to each other, with nozzles in one pair aligned parallel to the x-axis and nozzles in the other pair aligned parallel to the y-axis of a laser-beam similar to that delivered by the laser-head of FIG. 1 , with the number of nozzles in each plate through which powder is delivered being selectively adjustable.
[0016] FIG. 3B schematically illustrates detail of another configuration of the cladding-head of FIG. 3 similar to the configuration of FIG. 3A but having only the x-axis aligned powder-delivery plates.
[0017] FIG. 4A and FIG. 4B schematically illustrates detail of a powder delivery plate in the cladding-head of 3 B including a manifold having adjustment plugs adjustable to selectively isolate powder delivery nozzles from a powder supply.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Continuing with reference to the drawings, wherein like components are designated by like reference numerals, FIG. 3 schematically illustrates a preferred embodiment 50 of a laser-cladding-head in accordance with the present invention. Cladding-head 50 includes a flange 52 for attaching the cladding head to a laser-head similar to that of FIG. 1 .
[0019] An arrangement 56 is provided for providing x-y adjustment of the cladding head with respect to a laser-beam delivered by the laser-head and propagating through the laser head. A fixed member 58 of arrangement 56 is attached to flange 52 via a cylindrical extension 54 . A movable member 60 of arrangement 56 is movably attached to fixed member 58 . The x-position and y-position of member 56 with respect to member 58 are adjustable by knobs 62 and 64 , respectively. The relative x-y position of members 58 and 60 can be locked by a cam lever 57 .
[0020] The x-y adjustment method described above is but one suitable mechanism for achieving the adjustment. Those skilled in the art will recognize that other mechanisms could be used without departing from the spirit and scope of the present invention. Such mechanisms include jacking screws, cams, sliding wedges, sliding shims or any mechanism capable of providing linear motion in either two axes independently or simultaneously. In addition the x-y locking mechanism could take any number of forms including locking screws, jacking screws with locknuts, locking clamps, locking wedges or other devices used to restrain motion between moving objects.
[0021] A z-axis adjustment assembly 65 is attached to movable member 60 of the x-y adjustment via a threaded cylinder 68 A attached to the movable member. A complimentary threaded cylinder 68 B is attached to a mounting flange 74 . A rotatable threaded collar 70 connects cylinders 68 A and 68 B. Rotation of collar 70 is accomplished via an adjustment ring 64 having protruding pegs 66 to facilitate rotation of the collar as indicated by arrow A. Rotation of adjustment ring 64 translates into Z axis motion of the collar with respect to the sleeve, by moving cylinders 68 A and 68 B toward or away from each other, depending on the direction of rotation of collar 70 . The rotation position of the collar can be locked by a locking-ring 72 . Here again, this mechanism is only one of a number of possible mechanisms.
[0022] Continuing with reference to FIG. 3 , and with reference, in addition, to FIG. 3A , a powder delivery assembly 76 is attached, via a flange 78 thereof, to flange 74 of the z-axis adjustment assembly. Powder-delivery assembly 76 includes a hollow four-sided body 79 to which are attached one pair of powder-delivery modules (plates) 80 A and 80 B, and another pair of powder-delivery modules 80 C and 80 D (module 80 D is not visible in FIG. 3 ). Each powder-delivery module includes a plurality of nozzles 86 with orifices thereof arranged in-line. Cladding-powder from a source thereof (not shown) is fed into the modules entrained in an inert-gas under pressure via fixtures 82 A-D. A manifold within each module distributes the powder among the nozzles. Each, module here, also includes plugs 84 , which can be inserted or withdrawn, here, by screw-action, into or out of the manifold to select a number of nozzles through which powder can flow. This nozzle-selection process is described in detail further hereinbelow.
[0023] In powder-delivery assembly 76 , lines of nozzles in modules 80 A and 80 B are parallel to each other and parallel to the x-axis of the laser-beam passing through the assembly via aperture 88 therein. Lines of nozzles in modules 80 C and 80 D are parallel to each other and parallel to the y-axis of the laser-beam. This arrangement is suitable for square-shaped claddings discussed above as being suitable for building up thick cladding-layers. The x-y adjustment assembly 56 and the z-axis adjustment assembly 65 provide that the nozzle positions of modules 80 A-D are, collectively, independently adjustable in three axes with respect to laser-beam spot 18 in the working plane.
[0024] FIG. 3B schematically illustrates another possible configuration 76 A of powder-delivery assembly 76 . Here modules 80 C and 80 D of FIG. 3A have been removed and replaced with passive blocking plates 94 . Plates 94 have downward-extending portions 96 thereof arranged to minimize migration of powder in the x-axis direction out of the laser-beam spot. This configuration of powder modules is for above-discussed line-shaped clad-deposits suitable for depositing a large amount of cladding-material over a large area.
[0025] FIG. 4A and FIG. 4A schematically illustrate details of plug-arrangements described above for limiting the amount of active nozzles in a powder delivery module 80 . The shape of the modules is depicted, here, in simplified form. Powder is injected via a conduit 88 into a manifold 90 from which nozzles 86 extend. In FIG. 4A plugs 84 are shown sufficiently withdrawn from manifold 90 such that all, here ten, nozzles can transmit the injected powder. In FIG. 4B plugs 80 are inserted into manifold 90 such that only a central four of nozzles 86 can transmit powder. The examples of FIGS. 4A and 4B are for symmetrical arrangement of active nozzles. Clearly with the manifold-plug mechanism depicted, asymmetrical arrangements are also possible. Other mechanisms are possible for selecting active nozzles. One very simple mechanism would be selectively disabling any nozzle by inserting a pin or the like in the delivery-end of the nozzle. This could be used for example to change the spacing between active nozzles.
[0026] In summary the present invention is described above with reference to a preferred embodiment and certain specific examples. The invention, however, is not limited to this embodiment and examples. Rather, the invention is defined by the claims appended hereto.
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Powder-delivery apparatus for delivering powdered cladding-material into the vicinity of a laser-beam spot includes a plurality of powder-delivery modules. Each of the modules is arranged to receive the cladding-material and deliver the cladding-material through a plurality of nozzles. The position of the nozzles in the modules with respect to the laser-beam spot is adjustable in three Cartesian axes. The modules are selectively removable from, and attachable to the apparatus. Nozzles in any one of the modules can be selectively prevented from delivering cladding-material.
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FIELD OF THE INVENTION
[0001] The present invention relates to implantable hemodynamic monitors (IHMs). Specifically, the invention relates to systems that interface with various hospital monitoring systems to transfer data from the IHMs to doctors and other data processing centers. More specifically, the invention pertains to heart failure data management systems that provide a concise and reliable summary view of information in a manner that is useful for clinicians and health care personnel to monitor, assess, evaluate and treat heart failure conditions in patients. Further, the invention pertains to a system of a bi-directional communication system that is network, Internet, intranet and worldwide web compatible to enable chronic monitoring based on data obtained from the IHMs.
BACKGROUND OF THE INVENTION
[0002] The need to monitor, on a frequent and continuous basis, the vital signs associated with hospitalized patients particularly those who are seriously ill is an important aspect of health care. Virtually every hospitalized patient requires periodic measurement in logging of blood pressure, temperature, pulse rate, etc. Such monitoring has typically been performed by having a health care worker periodically visit the bedside of the patient and measuring and/or observing the patient's vital signs using dedicated equipment that is either hooked up to the patient or brought into the patient's room. Such a monitoring procedure is not ideally cost-effective because of its being highly labor intensive.
[0003] A great many implantable medical devices (IMDs) for cardiac monitoring and/or therapy whose sensors are located in a blood vessel or heart chamber and coupled to an implantable monitor or therapy delivery device are used for diagnosis and therapy. Such systems include, for example, implantable heart monitors, therapy delivery devices, and drug delivery devices. All these systems include electrodes for sensing and sense amplifiers for recording and/or deriving sense event signals from the intracardiac electrogram (EGM). In current cardiac IMDs that provide a therapy, sensed event signals are used to control the delivery of the therapy in accordance with an operating algorithm. Selected EGM signal segments and sensed event histogram data or the like are stored in an internal RAM for telemetry to be transmitted to an external programmer at a later time. Efforts have also been underway for many years to develop implantable physiologic signal transducers and sensors for temporary or chronic use in a body organ or vessel usable with such IHMs for monitoring a physiologic condition other than, or in addition to, the disease state that is to be controlled by a therapy delivered by the IMD.
[0004] A comprehensive listing of implantable therapy devices are disclosed in conjunction with implantable sensors for sensing a wide variety of cardiac physiologic signals in U.S. Pat. No. 5,330,505, incorporated herein in its entirety by this reference.
[0005] Typically, an IHM measures blood pressure and temperature signal values which stem from changes in cardiac output that may be caused by cardiac failure, ventricular tachycardia, flutter or fibrillation. These variations may reflect a change in the body's need for oxygenated blood. For example, monitoring of a substantial drop in blood pressure in a heart chamber, particularly the right ventricle, along or in conjunction with an accelerated or chaotic EGM, was proposed as an indicator of a fibrillation or tachycardia sufficient to trigger automatic delivery of defibrillation or cardioversion shock. More recently, it has been proposed to monitor the changes in blood pressure by comparing those values that accompany the normal heart contraction and relaxation to those that occur during high-rate tachycardia, flutter or fibrillation.
[0006] A number of cardiac pacing systems and algorithms for processing monitored mean blood pressure or monitored dp/dt have been proposed and in some instances employed clinically for treating bradycardia. Such systems and algorithms are designed to sense and respond to mean or dp/dt changes in blood pressure to change the cardiac pacing rate between an upper and a lower pacing rate limit in order to control cardiac output. Examples of IHMs blood pressure and temperature sensors that derive absolute blood pressure signals and temperature signals are disclosed in commonly assigned U.S. Pat. Nos. 5,368,040, 5,535,752 and 5,564,434, and in U.S. Pat. No. 4,791,931, all incorporated by reference herein.
[0007] The Medtronic® Chronicle™ Implantable Hemodynamic Monitor (IUM) disclosed in U.S. Pat. Nos. 6,024,704 and 6,152,885, both incorporated herein by reference in their totality, employ the leads and circuitry disclosed in the above-incorporated commonly assigned U.S Pat. No. 5,535,752 and U.S. Pat. No. 5,564,434 patents to record absolute blood pressure values for certain intervals. The recorded data is transmitted to a programmer under the control of a physician in an uplink telemetry transmission from the IHM during a telemetry session initiated by downlink telemetry transmission from the programmer's radio frequency (RF) head and receipt of an integration command by the IHM. Thus, in accordance to the '704 and '885 patents, a method is disclosed in which an IHM is used for deriving reference and absolute pressure signal values using implantable physiologic sensors to detect relative cardiac pressure signal values for storage and transmission.
[0008] Further, in accordance with the '704 and '885 patents, calibration of the reference pressure and/or temperature sensors in relation to an external calibrated barometric pressure and/or body temperature sensors could be accomplished. In addition, the same system may be used to interlace digital signal values related to pulmonary artery diastolic pressures with the primary cardiac pressure signal values derived from the right ventricle as disclosed in U.S. Pat. No. 6,155,267, incorporated herein by reference.
[0009] Heart failure is a progressive disease. While treatment slows the progression of the disease, current technology does not provide a cure. The best treatment regimen available to date is a combination of continuous diagnosis and drug therapy. Once a heart failure patient is in the hospital, current technology does not provide a continuous means of monitoring the patient during their stay in the hospital. Current practice is based on a dedicated programmer that is used to gain access to the pressure waveforms. Only trained physicians can currently uplink the data, and this is available only when such a trained physician is present, and is therefore not available on a continuous basis.
[0010] The present invention enables continuous remote monitoring of patients. In sharp contrast, prior heart failure management involves taking measurements of a few variables in the clinic with accurate catheterization pressures taken only occasionally because of the difficulty of obtaining them.
[0011] Accordingly, there is a need to provide continuous and reliable measurements over sustained long period of time. Further, emerging trends in health care including remote patient management systems require that the IMD/IHM be compatible with communication systems, including the Internet, the worldwide web, and similar systems to provide real-time communications and data exchange between the IHM in a patient and a remote center where physicians and other experts reside.
SUMMARY OF THE INVENTION
[0012] The present invention relates to chronic data management for cardiac systems. Specifically, the invention pertains to IHMs that monitor heart failure. In its broader aspect, the invention relates to patient management that enables the collection of chronic data for remote patient management, including remote delivery of clinical diagnosis and therapy.
[0013] Yet another aspect of the invention includes a user-friendly screen-displayable data management system that presents clinically relevant measurements. Another aspect of the invention provides a software system that enables the translation and transposition of IHM collected data to be presented to a clinician in a manner to enable efficient and reliable evaluation of patient conditions remotely.
[0014] The invention further relates to data reduction in a monitoring system as generally disclosed in co-pending application entitled “Implantable Medical Devices Monitoring Method and System Regarding Same” filed on Dec. 15, 1999, U.S. application Ser. No. 09/992,978, incorporated herein by reference in its entirety.
[0015] The present invention, inter alia, enables the transfer of a patient's medical data to one or more monitoring stations staffed by expert personnel to have access to the data in real time. Although the IHM device implemented in the present invention relates to the measurement of cardiac pressure, other IHM devices that detect and transmit additional physiological signals such as oxygen saturation, pulmonary artery diastolic and systolic pressure, temperature and related data may be used as the originating device or data source. Transferring real-time signals from IHMs to various physician portals and locations provides a highly accentuated medical service and effective chronic monitoring of patients.
[0016] In one aspect of the present invention an IHM device determines the hemodynamic status of a patient from measurement of pulmonary pressure and right atrial pressure obtained from a single absolute pressure sensor implanted in the right ventricle. Both of these values have been shown to correlate to the degree and extent of cardiac failure of a patient. The IHM continually monitors the right ventricular pressure using an absolute pressure sensor and marks the right ventricular pressure at the moment of specific events.
[0017] One aspect of the present invention is to provide a means by which physicians could view data available via real-time telemetry other than using a local data retrieving system, such as a programmer. Currently, physicians use the programmer to view the real-time pressure wave along with the EGM tracing. Using the present invention, the IHM device would be able to telemeter real time signals to a system via a programmer or other instrument to a remote location.
[0018] Another aspect of the present invention relates to the presentation of data from IHMs in a summary view that's useful and familiar to clinicians and patients. Yet another aspect of the present invention includes a process by which data is collected by IHMs, which data includes but is not limited to heart rate patient activity and pressure data, to establish that the patient is in a state of repeatable data routine on a daily basis. For example, this might mean application of a magnet when the patient is lying down, or using devices such as time-of-day counters, activity sensors, posture sensors, etc. Such data is retrieved for analysis via home monitors, programmers or similar devices, and the data sent over an Internet/intranet, worldwide web or a similar network to a remote location for analysis by clinicians or for storage and archiving at a Medtronic server.
[0019] The data is processed for collection with past pull-up records to compose a continuous patient record. Specifically, clinically relevant measurements are pulled out of the data. This would mean observing the average values measured during a daily test, including, for example, the patient reclining for 5 minutes. These values and the deviation or change are compared against clinical norms and flagged for the user if they are abnormal. For example, color plus footnote designations may be used to identify or flag abnormal data. Other variations such as italics, specialized fonts, bigger fonts, email reports, faxed reports may be used to identify deviations from normal clinical data or established chronological data for the patient. The clinical norms can optionally be modified for each patient by the clinician and then serve as a clinical baseline for the particular patient.
[0020] One other aspect of the present invention is the display of data which without limitation, includes the most recent daily test data along with data from the previously interrogated data. A comparative value between the two and a previous interrogation date to compare collected data with chronological data are used.
[0021] Yet another aspect of the present invention includes a single page view of chronic heart failure status, translation of raw data into clinical indicators of heart failure status, analysis of changes in indicators over a user-selectable time period, flags and indicators to identify changes that are outside of clinical norms, tailoring of graphical displays and data management to a patient's clinical norms, means to determine if the patient is in a state of repeatable condition from day to day, and automated data analysis triaging which provides a foundation for further data analysis and automation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1A shows a diagram illustrating an implantable medical device that incorporates an absolute cardiac blood pressure sensor and an IHM device in accordance with the present invention.
[0023] [0023]FIG. 1B is a block diagram illustrating various data communication systems from the IMD.
[0024] [0024]FIG. 1C is a block diagram illustrating signal transmission from the IMD to a remote station.
[0025] [0025]FIG. 2 is a block diagram illustrating the remote communication system within which the present invention is incorporated.
[0026] [0026]FIG. 3 is a block diagram representing a web browser and portal interface for the present invention.
[0027] [0027]FIG. 4A is a block diagram representation illustrating a Medtronic home page at the Medtronic server in which data may be archived in accordance with the present invention.
[0028] [0028]FIG. 4B is a logic flowchart representing high level quick look summary in accordance with the present invention.
[0029] [0029]FIG. 5A is a representative sample of a welcome screen.
[0030] [0030]FIG. 5B is a representative hemodynamic variables display screen.
[0031] [0031]FIGS. 6& 7 is a quick look summary in accordance with the present invention.
[0032] [0032]FIG. 8 is a representative screen for a trends report.
[0033] [0033]FIG. 9 is a representative screen for a trends report similar to FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] [0034]FIG. 1A represents a patient with implanted medical device incorporating an absolute cardiac blood pressure sensor such as the IHM discussed hereinabove. Specifically, IHM/IMD 100 is coupled to an absolute cardiac blood pressure sensor 120 in a patient's heart 10 for recording absolute blood pressure values. IMD 100 is depicted implanted subcutaneously in the patient's chest region and it is coupled at its connector module 180 to a lead 112 extending through blood vessels into the right ventricle of the patient's heart 10 . The blood pressure sensor 120 is located on lead 112 just proximal to the lead's distal tip 130 for passively fixing it in position to accommodate continuous movement of the heart 10 . In this structure lead 112 and blood pressure sensor 120 correspond to those disclosed in detail in the above-incorporated commonly assigned '434 and '752 patents for deriving absolute blood pressure. The IMD 100 that monitors the physiological condition or state is programmable and/or can be interrogated by an external instrument such as a programmer through the use of bidirectional or RF telemetry that exchanges data and commands via uplink and downlink RF telemetry transmissions through the patient's skin.
[0035] In the context of an implantable blood pressure monitor a series of absolute blood pressure signal values are sensed periodically or in response to a signal provided by hospital personnel for example, a telemetry downlink signal to initiate real time data transmission. The absolute blood pressure value signals are continuously transmitted so that physicians, clinicians, nurses or other medical experts can determine the status of the patient's cardiac pressures and associated episodes recorded within the required time of day. The physician uses an external programmer to generate and transmit an interrogation command via a downlink telemetry transmission to the IMD 100 . IMD 100 recognizes the command and initiates a continuous uplink telemetry transmission of the absolute pressure data in response. The uplink telemetry continues until the IMD system fails to detect further commands.
[0036] [0036]FIG. 1B illustrates a general scheme by which patient data could be transmitted to a remote clinician's station. The communication scheme enables continuous monitoring of patients either in a hospital setting or in a home environment. Pressure signals are acquired from the IMD via telemetry head 22 or equivalent device and uplinked to instrument 24 . Instrument 24 may represent a programmer or an in-home monitor adapted to communicate with IMD 20 . Instrument 24 maintains wireless communication 27 to transfer data to clinician's station 28 . Alternatively, instrument 24 may be adapted to transfer data via network 30 representing Internet, extranet, worldwide web or a similar network. The data is then transferred to clinician's station via modem, cable or equivalent data transfer system.
[0037] [0037]FIG. 2 represents a detailed aspect of network 30 that is accessible to patients and physicians within which search engine 40 enables access to various zones 42 , including a dedicated public zone 44 , confidential zone 46 and private zone 48 . These zones represent various data management centers that are either interconnected or segregated based on privacy and security requirements. For example, public zone 44 is accessible to all patients, physicians and the public to provide general information about medical devices and related medical information and services. In sharp contract, confidential database 46 and private information 48 are accessible to patients and physicians based on strict security and encryption systems for access on a need-to-know basis.
[0038] Referring now to FIG. 3, web browser and portal interface 50 representing patient portal 52 , physician portal 54 and Medtronic (MDT) portal 56 are shown. These portals share a common database with additional secure database 58 and encryption system 60 interconnected therewith.
[0039] [0039]FIG. 4A is a general representation of a Medtronic home page 70 in accordance with the present invention. The home page is segregated between public and private/secure pages. Specifically, a physician section, patient section and a general public information section are depicted. The physician's section is highly scalable and operates both on the public and private secure sections. Similarly, the patient section relates to information on various medical devices including related therapy and diagnosis. Further, similar to the physician's site, the patient site includes private/confidential segments.
[0040] [0040]FIG. 4B represents a general logic flow diagram for a quick look summary in accordance with the present invention. Specifically, the system is initiated under logic step 80 where long-term data is collected via IMD 100 . The long-term data is refined to determine if the patient is in a repeatable state under logic step 82 . Subsequently, the data is retrieved and processed under logic step 84 . Thereafter, under decision step 86 the values of the processed data are reviewed to see if they are abnormal. If these values prove to be abnormal, they are flagged as abnormal values under logic step 88 and the results are displayed under logic step 90 . In the alternate, if the values are found to be normal, they are displayed under logic step 90 . One of the significant aspects of the present invention is the presentation of highly user-friendly quick look summary of data collected by IMD/IHM 100 to clinicians, patients and other health providers.
[0041] Referring now to FIG. 5A, a representative screen encountered by a doctor using the Internet site provided in accordance with the present invention is shown. Specifically, the screen includes various tabs, one of which is to welcome the user. The welcome screen identifies the doctor and updates him or her on how many home monitoring records have been reviewed and how many abnormal events have been detected. The doctor is also informed of the number of patients who may require review. The doctor is also given various information regarding his or her practice and is also informed on what is new in the art vis a vis specific devices and medical conditions. The screen is highly interactive and based on past site use behavior of the doctor, the software is able to understand and retain the doctor's interests and highlight unused features.
[0042] In the “What is New” section, for instance, the screen interactively provides the doctor with the latest information regarding clinical studies including the devices that are released in the user's countries. The “Links” section provides links to related medical sites. The list of links is maintained by Medtronic, so only approved sites will appear. The list of potential links is narrowed by the user's areas of interest. Clinicians can also provide recommended links to their patients. This will appear in the patient portal and are customized by the recommended links, the type of devices the patient has implanted, the local language to be used and a track record of previous links that have been used.
[0043] Further, patient records of device and recorded data will be available for viewing and entry. This data may have been collected by home monitors, programmers, extenders, registration database or imported from clinic databases. Users can arrange the view of records, listable to their liking by date, name, ID and status. Specifically, status indicators are used for home monitoring data yet to be viewed or with errors. The records may include in-office follow-up test results, interrogated diagnostic data settings and measurements, data imported from pacing databases such as EKG indication, medications including control of compliance, monitoring functions, key physiologic data such as indications for implant, links to other online components of a patient's chart such as lab results, notes entered, data integrated across patient sessions such as episode logs and trends, patient demographics and patient diary entries.
[0044] The system may also be customized based on whether the portal is used to store in-home or programmer records for the particular patient. All parts of the patient's records that are attributable to the patient are clearly patient private data. Encryption and adequate authentication must be used for access. Attribution of who enters and edits changes is also supported by the system software.
[0045] Appointment scheduling provides an automatic means for scheduling home-monitoring sessions so home monitoring could be conducted without additional burden on the clinic scheduling staff. Physicians may enter their prescribed follow-up intervals and then the system can schedule the follow-up days. Patients can customize their schedule without the help of the clinical staff. The scheduling may also integrate with the clinic's in-office scheduling enabling doctor appointments to be made online.
[0046] Accounts billing are automated. Automation of the filling out of billing statements is also provided. Medical device follow-up regiments can often automatically be determined from session data. The data is forwarded to the clinician's billing system or a third party billing clearing house. Medtronic device registration forms will be web-enabled. Direct entry on the web or import from un-tethered data entry applications will be supported. Entry on the web will enable access by customers rather than field representatives without the high distribution and support cost encountered today with PC applications.
[0047] Clinical study content will be available to clinical study investigators. This could include entry of clinical data forms, discussion groups, newsletter and results reports. The site is customized based on which studies the user is a part of and the local language used. Physicians can compare their practice by comparing their practice data to data aggregated from other practices and practice guidelines. Specific comparison and points can be offered with custom filters. Eventually data mining may be offered. This will include and expand on the current capabilities of the CV views extranet applications. This part of the site could be customized based on collected user's data that is also made available for comparisons. Further, information about the user's practice to derive comparison definitions, for example with other practitioners in the area of expertise may be provided.
[0048] The site also includes reports for tracking product performance and will maintain tags on the referring physician. The distribution of reports is greatly enhanced through web-enabled features. Specifically, the content is tailored to each practice. For example, product performance can be incorporated with web devices such as a palm device which may be on the person of the patient or the physician. Similarly, the accuracy of reports can be enhanced by joining data. For example, closer monitoring reports may contain more accurate battery projections derived from follow-up and continuous monitoring of actual device data.
[0049] The system enables remote viewing. Specifically, users can remotely view patient stations through instruments connected to the Internet 30 . Sessions with programmers, extenders, acute monitors and home monitors will be viewed through web browsers or a PC. Users will have access to a switchboard of available instruments they have rights to connect to and access the contents thereof. The connection is supported in any order whether it is browser or instrument first. Preferably, the site is customized by identifying which instruments the user has access rights to. Rights are assigned to physicians and clinical personnel as needed.
[0050] In the same manner, the link for patient portal 52 is a secure website for patients already implanted with Medtronic devices and their families. It includes the web content that requires secure access not available in the Medtronic public website 56 . Patient portal 52 provides personalization, automatically providing only the information pertinent to the patient's device and disease. This is combined with a consistent user interface for the diverse applications being provided for a highly distributed user-friendly web experience.
[0051] Welcome screen 155 of FIG. 5A highlights important information with more detailed features. The site is customized by patient's names, what devices the patient has implanted, marketing preferences of what news or new products are of interest, physician control of what the patient has access to, past portal use to understand interests and highlight unused features, and what local language the patient uses.
[0052] One of the significant aspects of this site includes a home monitoring section which closes the loop for home-monitored patients. These patients can view whether sessions were successful or trouble-shoot errors. They can gain reassurance by viewing high-level results. Clearly this will reduce the burden of phone calls on clinicians. The site is customized by results of home monitoring sessions. The type of implanted device and home monitor that are proper to a patient are generally decisions made by the patient's physician. For security reasons home monitoring results may be considered patient private data and will require encryption and user authentication. The site also provides appointment scheduling in which an automated means for scheduling home-monitoring sessions is implemented without additional burden on clinic scheduling staff. Physicians can enter their prescribed follow-up intervals and the system is intelligent to schedule the follow-up days. Patients can customize their schedule without the help of the clinical staff. The scheduling may also integrate with a clinic's in-office scheduling enabling doctor appointments to be made online.
[0053] Patient portal 52 also includes a diary section where daily medical journal entries can be captured. Voice or text can be captured either on the diary screen or potentially on a home monitor. Regardless of where it is entered, the diary screens would provide options to review and edit the contents of a diary. By putting the diary online, it is instantly available to all medical caregivers. Further, the diary does not need transcription or transfers to become part of a medical chart because of automatic entry.
[0054] Yet another significant aspect of the screen display at patient portal 52 includes the management of patient ID cards. Requests for replacements and validation of patient's information is automated on patient portal 52 . Patients can also print out replacement ID cards for use while the processing of a permanent card is in progress. Patient portal 52 also enables patients to control the rights to their records. Specifically, patients will have rights to grant control and access rights to their records as they may deem necessary.
[0055] Referring to FIG. 5B, a quick look summary of hemodynamic variables 125 is represented. The screen provides one-week trends for hemodynamic variables RV pressure waves. For example, triggered episodes could be selected under a tachy-, brady- or patient-triggered events. A tachy-triggered event, for example, would inform the user if the patient has tachy-triggered events. Similarly, a brady-triggered event informs the user if the patient has brady-triggered events. Further, patient-triggered events relate to information indicating patient-triggered events.
[0056] Referring to FIG. 6, quick look summary screen 140 represents various parameters useful to determine a tachy or brady trigger. A tachy-trigger notification informs the user if the patient has tachy-triggered events. If there are tachy-triggered events the device information network for example, IHM 100 , will notify the designated person, for instance a nurse, doctor or health provider electronically that events have occurred by email, pager or other means. Similarly, a brady-triggered notification would be dispatched in the event there are brady-triggered events. IHM 100 will notify the designated person about the event. Patient-triggered notification is also dispatched in the same manner.
[0057] Referring to FIG. 7, under display screen 150 , the software system enables analysis of comparative values based on a comparison of recent values to values interrogated on a prior time period. Patient portal 52 and physician portal 54 provide various ways of presenting clinical information. Specifically, daily minimums of heart rate for quick look, RV systolic pressure, daily minimums of RV diastolic pressure, daily minimums of estimated pulmonary artery pressure, daily minimums of RV pulse pressure, daily minimums of RV dp/dt, highlighting out-of-range heart rate, highlighting out-of-range RV systolic pressure, highlighting out-of-range RV diastolic pressure, highlighting out-of-range ePAD pressure, highlighting out-of-range RV pulse pressure, highlighting out-of-range RV dp/dt, notification of heart rate out-of-range, notification of RV systolic pressure out-of range, notification of RV diastolic pressure, notification of ePAD pressure, notification of RV pulse pressure, notification of RV dp/dt out-of-range, highlighting changes in heart rate. Specifically, the quick look will determine and report changes in heart rate which have occurred in a patient between the daily minimum values contained in the file selected for examination and the daily minimum values from a previous file. More specifically, values are compared to determine if the differences lie outside a user-defined threshold is defined in the quick look setup and can be tailored on a patient-by-patient basis. This feature allows the user to define differences either based on actual values or percentages. Highlighting changes in RV systolic pressure relates to pressures which have occurred in a patient between the daily minimum values contained in the file selected for examination and the daily minimum values from a previous file.
[0058] Highlighting changes in RV diastolic pressure enables the quick look to determine and report changes in RV diastolic pressure which have occurred in a patient between the daily minimum values contained in the file selected for examination and the daily minimum values from a previous file. Similarly, the quick look will determine and report changes in RV pulse pressure which have occurred in a patient between the daily minimum values contained in the file selected for examination and the daily minimum values from a previous file. Highlighting changes in RV dp/dt includes determination and reporting of changes in RV dp/dt which have occurred in the patient between the daily minimum values contained in the file selected for examination and the daily minimum values from a previous file. Notification of large heart rate change is implemented by enabling IHM 100 information network to notify a designated person electronically that changes in heart rate greater than set targets have occurred. A notification may be sent by e-mail, pager and an equivalent medium.
[0059] Similar notification of large RV systolic pressure changes, large RV diastolic pressure changes, large ePAD pressure changes, large RV pulse pressure change, and RV dp/dt changes may be made. The quick look allows the user to select from a list of previous files. A specific file may be selected for data against which the current file is compared to determine if hemodynamic values have changed. Accordingly, quick look compares the daily minimum values from the selected file set of previous files to show the user variation that may have occurred. Additionally, while the quick look page allows the user to examine a selected file, its comparison to threshold values and comparison to a previous file, it also provides the daily minimum plots to enable the user to see a time/trend plot of all daily minimum values for all variables. Further, a daily minimum list may be used to examine a selected file, its comparison to threshold values and its comparison to a previous file to see a listing of all daily minimum values for all variables.
[0060] Referring now to FIGS. 8 and 9, trends report 160 and 170 are represented. Specifically, heart rate, patient activity, systolic and diastolic pressures and similar cardiac/physiologic parameters collected over a period of several weeks. Trend reports for night heart rate, +dp/dt and dp/dt including pre-ejection systolic time intervals may be displayed. Trend directions for 12 months to 1 hour may be selected for review.
[0061] The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood, therefore, that other expedients known to those of skill in the art or disclosed herein may be employed without departing from the invention or the scope of the appended claim. It is therefore to be understood that the invention may be practiced otherwise than is specifically described, without departing from the scope of the present invention. As to every element, it may be replaced by any one of infinite equivalent alternatives, only some of which are disclosed in the specification.
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Continuous remote monitoring of patients based on data obtained from an implantable hemodynamic monitor provides an interactive patient management system. Using network systems, patients are remotely monitored to continuously diagnose and treat heart-failure conditions. A screen displayable summary provides continuous feedback and information to physicians, patients and authorized third parties. The quick look summary includes various sites and presentation tailored to match the patients' and physicians' needs. The quick look summary further includes intelligent features that understand and retain the user's interests, preferences and use patterns. Patients, physicians and other caregivers are seamlessly connected to monitor and serve the chronic needs of heart-failure patients in a reliable and economic manner.
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TECHNICAL FIELD
[0001] The present invention relates to the control of an internal combustion engine. More specifically, the present invention relates to controlling an internal combustion engine upon the failure of a crankshaft position sensor.
BACKGROUND OF THE INVENTION
[0002] Presently, automotive companies manufacture data or target wheels for use with speed sensors to detect the speed, timing, and position of an engine crankshaft and/or a camshaft. As is known in the art of four-cycle internal combustion engines (ICEs), position and timing information for a crankshaft and a camshaft is very important to the application and synchronization of spark and fuel. The crankshaft is actuated by combustion in the pistons, and the camshaft actuates the intake and exhaust valves of the pistons. A camshaft may be used in an overhead valve (OHV) configuration where the valves are actuated via pushrods, or in an overhead cam (OHC) configuration where the valves are acted on directly by the camshaft. The camshaft is driven by the crankshaft through a 1:2 reduction (i.e., two rotations of the crankshaft equal one rotation of the camshaft) and the camshaft speed is one-half that of the crankshaft. The crankshaft and camshaft position, for engine control purposes, are measured at a small number of fixed points, and the number of such measurements may be determined by the number of cylinders in the ICE.
[0003] In today's engine control systems, crankshaft speed supplied by a crankshaft sensor provides position, timing, and/or speed information to an electronic controller for controlling the application of spark and fuel to the cylinders of an ICE. The position and timing (phase) of a first camshaft controlling exhaust valves for a cylinder and/or a second camshaft controlling intake valves for a cylinder in an OHC engine may be controlled relative to the crankshaft (piston position) to reduce emissions and improve fuel economy. Several cam-phasing devices exist in today's automotive market that require accurate position and timing information provided by a camshaft position sensor.
[0004] A crankshaft or camshaft position sensing system typically includes a variable reluctance or Hall effect sensor positioned to sense the passage of a tooth, tab, and/or slot on a target or data wheel coupled to the crankshaft or camshaft. In a four-cycle ICE, the electronic controller must further differentiate the intake, compression, power, and exhaust strokes since the cylinders will be approaching top dead center (TDC) position during the compression and exhaust phases and approaching bottom dead center (BDC) position during the intake and power phases. Accordingly, the application of fuel and spark in a typical ICE will not be applied until enough position information has been obtained from the crank position sensing systems. Thus, the engine controller must not only determine the TDC and BDC positions of the cylinder but also the state of the engine cycle to control fuel and spark. In the event of a failure of the crankshaft position sensor or system, engine timing must somehow be determined to allow a vehicle to function well enough to travel to a destination where the failure can be fixed.
SUMMARY OF THE INVENTION
[0005] The present invention comprises a method and apparatus to allow a vehicle engine to operate in the event of a crankshaft sensor failure used in sensing systems common to four cycle ICEs, including but not limited to four-, five-, six- and eight-cylinder engines. The camshaft position sensing system of the present invention, specifically the sensor and target wheel used to provide position information for the camshaft and phasing of the camshaft, may be used to provide timing signals for control of fuel and spark in the event of a crankshaft sensor failure.
[0006] The present invention utilizes a 4× target wheel cam with four. binary (state encoded) base periods for engine cam timing functions. Each semi-period or state is bounded by a rising and falling edge that are a fixed angle before TDC for one or more cylinders of all four, five, six, and eight cylinder engine configurations. For five- or six-cylinder engine configurations, a 4× target wheel used in a camshaft sensing system may not provide accurate information on the position of a particular cylinder/piston. If spark is applied too early to a cylinder (the cylinder is over-advanced by 20-30 degrees), a negative torque spike may occur. The negative torque spike can create stress on the crankshaft and be transmitted through the crankshaft to a starter motor. Starter motors are typically mounted by a flange to an engine block and are connected to the crankshaft through a coupling such as a gear box or belt. The negative torque spike created by the mis-timing of fuel and spark to an engine may destroy the starter motor coupling or fracture the engine block.
[0007] The present invention utilizes the 4× target wheel of the camshaft positioning system to provide backup or redundant information to an engine controller for engine timing. Furthermore, for certain engine types such as five-cylinder or six-cylinder engines, the application of spark and fuel for certain cylinders may be prevented to eliminate a negative torque spike. Fuel and spark are supplied to the engine sequentially, one cylinder at a time. When a position within a 720 degree engine cycle is reached where a fuel injector or ignition event for a cylinder can create an over-advance condition, ignition in that cylinder is prevented by turning off the fuel injector and/or spark ignition device. The absence of fuel and spark to that individual cylinder ensures that the cylinder does not produce any torque, positive or negative. All cylinders that cannot generate the over-advance condition are operated with normal fuel injection and spark events.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The various advantages of the present invention will become apparent to one skilled in the art upon reading the following specification and by reference to the drawings in which:
[0009] [0009]FIG. 1 is a diagrammatic drawing of the engine and cam sensing system of the present invention;
[0010] [0010]FIG. 2 is a diagrammatic drawing of a 4× target wheel used for camshaft position sensing in the present invention; and
[0011] [0011]FIGS. 3A, 3B and 3 C are timing diagrams illustrating the signals generated by the position sensing systems of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] [0012]FIG. 1 illustrates an internal combustion engine 10 having a crankshaft 12 . The speed of the crankshaft 12 is communicated in the form of periodic signals generated by the rotation of a target wheel 15 on the crankshaft 12 by a conventional wheel speed sensor 16 . The wheel speed sensor 16 may comprise any known wheel speed-sensing device including, but not limited to, variable reluctance sensors, Hall effect sensors, optical switches and proximity switches. The purpose of the wheel speed sensor 16 is to detect the teeth on the target wheel 15 and provide a pulse train to an electronic controller 22 . The electronic controller 22 , in conjunction with other sensors, will determine the speed and position of the crankshaft 12 using the periodic signals generated by the speed sensor 16 .
[0013] The vehicle controller 22 may be any known microprocessor or controller used in the art of engine control. In the preferred embodiment, the controller 22 is a microprocessor, having nonvolatile memory NVM 26 such as ROM, EEPROM, or flash memory, random access memory RAM 28 , and a central processing unit CPU 24 . The CPU 24 executes a series of programs to read, condition, and store inputs from vehicle sensors. The controller 22 uses various sensor inputs to control the application of fuel and spark to each cylinder through conventional spark and fuel injector signals 30 . In the preferred embodiment of the present invention, the fuel injectors are configured as port injectors where each cylinder is supplied with fuel from a fuel injector. The controller 22 further includes calibration constants and software stored in NVM 26 that may be applied to control numerous engine types.
[0014] In the preferred embodiment of the present invention, as shown in FIG. 1, the engine 10 is shown with exhaust camshaft 14 and intake camshaft 19 . The exhaust camshaft 14 and intake camshaft 19 are coupled to the crankshaft 12 via sprockets and a timing chain 25 . The exhaust camshaft 14 actuates exhaust valves for the cylinders, and the intake camshaft 19 actuates intake valves for the cylinders, as is commonly known in the art. A target wheel 23 coupled to the exhaust camshaft 14 generates periodic signals using wheel position sensor 18 to provide speed and position information for the exhaust camshaft 14 . The wheel position sensor 18 may be similar in functionality to wheel speed sensor 16 .
[0015] The present invention may further be equipped with a continuously variable cam phaser 32 , as is known in the art. The cam phaser 32 in the preferred embodiment may be coupled to the exhaust camshaft 14 . In alternate embodiments of the present invention, a cam phaser 32 may be coupled to the intake camshaft 19 or to both the exhaust and intake camshafts 14 , 19 , depending on the desired performance and emission requirements of the engine 10 . The cam phaser 32 is hydraulically modulated to create a variable rotational offset between the exhaust camshaft 14 and the intake camshaft 19 . The degrees of rotational offset generated by the cam phaser 32 enables the ICE 10 to be tuned for specific performance requirements by varying valve overlap, i.e., overlap between the exhaust and intake valves of the engine 10 .
[0016] [0016]FIG. 2 is a diagram of the target wheel 23 of the preferred embodiment of the present invention that will be described in conjunction with a timing diagrams of FIGS. 3A, 3B and 3 C. The target wheel 23 includes an irregular surface having teeth, slots, or tabs 40 . The teeth 40 have edges E 1 -E 8 for generating a pulse train for the wheel position sensor 18 .
[0017] Referring to FIGS. 3A, 3B and 3 C, a timing diagram is shown with a series of exhaust, intake and ignition events, a pulse train 52 generated by the target wheel 15 and target wheel sensor 16 , and pulse trains 54 generated by the target wheel 23 and target wheel position sensor 18 . Plot 54 a corresponds to timing events for a four-cylinder engine, plot 54 b corresponds to timing events for a five-cylinder engine, plot 54 c corresponds to timing events for a six-cylinder engine, and plot 54 d corresponds to timing events for an eight-cylinder engine. The pulse train 54 includes edges E 1 -E 8 that correspond to the physical layout of the teeth 40 on target wheel 23 . The edges E 1 -E 8 signal the controller 22 the position and speed of the exhaust camshaft 14 and the state of the crankshaft 12 (i.e., is it in the compression or exhaust phase) and corresponding cylinders to allow the application of spark and fuel by the controller 22 in the case of a failure of target wheel sensor 16 for the crankshaft 12 .
[0018] During the operation of an engine such as a five- or six-cylinder engine, the crankshaft target wheel sensor 16 may fail or other failures may occur that prevent timing information to be recorded from the target wheel sensor 16 . In such cases, the vehicle may operate using the camshaft target wheel 23 and position sensor 18 . The position information provided by the position sensor 18 can be used to determine the application of fuel and spark to the engine 10 . A 4× target wheel such as target wheel 23 in certain situation may not provide reliable position and timing information for the engine 10 . Referring to FIGS. 3A, 3B and 3 C, plot 54 b and edges E 6 , E 8 , El, E 2 and E 5 will be used to provide crankshaft position information. Cylinders A, B, C, D and E for a five-cylinder engine can be referenced in plot 54 b for a five-cylinder engine.
[0019] In the preferred embodiment of the present invention, the edges E 6 , E 8 , El, E 2 , and E 5 for a five-cylinder engine produce a signal thirty-six degrees from the TDC position for cylinder A, zero degrees from the TDC position for cylinder B, twelve degrees after the TDC position for cylinder C, one hundred-eight degrees from the TDC position for cylinder D, and forty-eight degrees from the TDC position for cylinder E. If the speed can be predicted correctly, accurate firing of spark and the application of fuel can be done with reference to the edges E 6 , E 8 , E 1 , E 2 , and E 5 . In certain operating conditions for the cylinder D, the engine 10 may slow down, as shown by the plot 52 in FIG. 3C. The predicted position 50 and actual position 52 of the piston may be inaccurate. The piston could be in an over-advanced position where negative torque will be generated by spark and fuel. In such a situation, spark and/or fuel may be cut off to that particular cylinder to prevent the negative torque spike.
[0020] When E 2 is reached, this would be the normal event to turn on a fuel injector or set up a ignition event for cylinder D. However, since ignition at this event can cause an over-advance condition, cylinder D ignition is prevented by turning off the fuel injector and/or spark ignition device. The absence of fuel and spark to cylinder D ensures it does not produce any torque, positive or negative
[0021] While this invention has been described in terms of some specific embodiments, it will be appreciated that other forms can readily be adapted by one skilled in the art. Accordingly, the scope of this invention is to be considered limited only by the following claims.
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A method of providing engine timing information for an engine having a plurality of cylinders including detecting a fault for a crankshaft sensor generating engine timing information with a camshaft sensor, providing spark and fuel with the engine timing information generated by the camshaft sensor, and shutting off fuel to at least one of the cylinders.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a novel optically active compound and a liquid crystal composition containing the same. More particularly, it relates to an optically active compound useful as a component of a ferroelectric liquid crystal composition and a ferroelectric liquid crystal composition containing the same.
2. Description of the Prior Art
Although the practical use of a liquid crystal element has started with the application thereof to the display of a watch or an electronic calculator, it is now applied to a wider field including pocketable televisions, various displays and optoelectronic elements. Most of the liquid crystal display elements now in use are of TN display type wherein nematic liquid crystal materials are used. Since this type of display is of photoreception type, it has disadvantages in that the speed of response is low and that the displayed images cannot be seen at some angles of vision, though it has advantages in that the eyes get little tired and that the power consumption is very low. In order to overcome these disadvantages, a display system using a ferroelectric liquid crystal has recently been proposed. Even in a display element of this type, like in the case of the above mentioned TN liquid crystal display element, a ferroelectric liquid crystal must be practically used in a state mixed with several liquid crystal or non-liquid-crystal compounds, i.e., as a so-called ferroelectric liquid crystal composition, in order to satisfy various characteristics.
On the basis of this idea, Japanese Patent Laid-Open No. 44548/1988 proposed the use of an optically active 2-methyl-1,3-propanediol compound as a component of a ferroelectric liquid crystal composition. However, such a ferroelectric liquid crystal composition is not sufficiently improved in the speed of response, if any. Accordingly, a further improvement in the speed of response of a ferroelectric liquid crystal composition has been expected in order to put the composition to practical use.
SUMMARY OF THE INVENTION
Under these circumstances, the inventors of the present invention have intensively studied to find out an optically active compound which can give a ferroelectric liquid crystal composition excellent in the speed of response and have found that a novel optically active compound represented by the following general formula (I) is very suitable for this object: ##STR3## wherein R stands for a C 1 ˜18 alkyl group;
R'stands for a C 1 ˜18 alkyl group which may be
substituted or an aryl group; X stands for ##STR4## or --O-- and an asterisk refers to an optically active carbon atom.
The compound represented by the general formula (I) does not exhibit any liquid crystal phase near room temperature. However, when the compound is added to a matrix liquid crystal having an SmC or SmC* phase, it imparts a large spontaneous polarization to the SmC or SmC* phase while scarcely lowering the phase transition temperature of the matrix liquid crystal between SmA and SmC or SmC* to form a chiral smectic phase exhibiting a high-speed electric field response.
Accordingly, the compound of the present invention is useful as a component of a ferroelectric liquid crystal composition. Further, a ferroelectric liquid crystal composition containing the compound according to the present invention is also extremely useful in practical use.
DETAILED DESCRIPTION OF THE INVENTION
The compound represented by the general formula (I) will be described in more detail.
The C 1 ˜18 alkyl group defined with respect to R includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, lauryl, myristyl, palmityl and stearyl groups.
The C 1 ˜18 alkyl group defined with respect to R', which may be substituted, includes those listed above with respect to R.
Although the optically active compound of the present invention represented by the general formula (I) does not always exhibit properties as a ferroelectric liquid crystal by itself, it may be mixed with other liquid crystal or non-liquid-crystal compounds to give a practically usable liquid crystal composition. Representative examples of the compound to be mixed include the following compounds, though not limited to them: ##STR5##
These compounds may also be used as a mixture of two or more of them in an arbitrary ratio depending upon the object of the use.
In the liquid crystal composition of the present invention, the optically active compound of the present invention is preferably used in an amount of 1 to 50 parts by weight, still preferably 5 to 40 parts by weight, per 100 parts by weight of a matrix liquid crystal (other liquid crystal or nonliquid-crystal compound).
The present invention will now be described by referring to the following Examples, though it is not limited by them.
EXAMPLE 1 (SYNTHESIS EXAMPLE 1)
Synthesis of (1"R,3"R)-2-(4'-n-octylphenyl)-5-[4'-(1"-methyl-3"-butanoyloxybutyloxy)phenyl]-pyrimidine (Compound No. 1) ##STR6##
0.62 g of (S,S)-2,4-pentanediol, 1.80 g of 2-(4'-n-octylphenyl)-5-(4"-hydroxyphenyl)pyrimidine, 1.57 g of triphenylphosphine and 1.21 g of diisopropyl azodicarboxylate were dissolved in 25 ml of ethyl ether to obtain a solution. This solution was stirred at a room temperature for 2.5 hours. The triphenylphosphine oxide thus precipitated was filtered off and the filtrate was freed from the solvent. The solvent-free residue was purified by silica gel column chromatography using a n-hexane/ethyl acetate (7 : 3) mixture as a developing solvent to obtain 1.62 g of (1"R,3"S)-2-(4'-octylphenyl)-5-[4'-(1"-methyl-3"-hydroxybutyloxy)phenyl]pyrimidine.
Then, 0.90 g of the pyrimidine compound, 0.18 g of butyric acid, 1.31 g of triphenylphosphine and 1.01 g of diisopropyl azodicarboxylate were dissolved in 5 ml of ethyl ether. The obtained solution was stirred at a room temperature for 2 hours. The triphenylphosphine oxide thus formed was filtered off and the filtrate was freed from the solvent. The residue was purified by silica gel column chromatography using a n-hexane/ethyl acetate (80:20) mixture as a developing solvent to obtain 0.77 g of a colorless oil.
The infrared spectroscopic analysis of the oil revealed that the oil had the following characteristic absorptions and it was thus identified with the objective compound:
______________________________________2950 cm.sup.-1 (s), 2890 cm.sup.-1 (w), 1735 cm.sup.-1 (s),1615 cm.sup.-1 (m), 1585 cm.sup.-1 (m), 1520 cm.sup.-1 (m),1435 cm.sup.-1 (s), 1380 cm.sup.-1 (m), 1290 cm.sup.-1 (m),1250 cm.sup.-1 (s), 1190 cm.sup.-1 (m), 1155 cm.sup.-1 (w),1110 cm.sup.-1 (w), 840 cm.sup.-1 (m), 800 cm.sup.-1 (w),______________________________________
EXAMPLE 2 (SYNTHESIS EXAMPLE 2)
Synthesis of (1"S,3"S)-2-(4'-n-octylphenyl)-5-[4'-(1"-methyl-3"-butanoyloxybutyloxy)phenyl]-pyrimidine (Compound No. 2) ##STR7##
The same procedure as that of Example 1 was repeated except that (R,R)-2,4-pentanediol was used instead of the (S,S)-2,4-pentanediol to obtain a product.
The infrared spectroscopic analysis of the produce revealed that the product had the following characteristic absorptions and it was thus identified with the objective compound:
______________________________________2950 cm.sup.-1 (s), 2890 cm.sup.-1 (w), 1735 cm.sup.-1 (s),1615 cm.sup.-1 (m), 1585 cm.sup.-1 (m), 1520 cm.sup.-1 (m),1435 cm.sup.-1 (s), 1380 cm.sup.-1 (m), 1290 cm.sup.-1 (m),1250 cm.sup.-1 (s), 1190 cm.sup.-1 (m), 1155 cm.sup.-1 (w),1110 cm.sup.-1 (w), 840 cm.sup.-1 (m), 800 cm.sup.-1 (w)______________________________________
EXAMPLE 3 (SYNTHESIS EXAMPLE 3)
Synthesis of (1"R,3"S)-2-(4'-n-octylphenyl)-5-[4'-(1"-methyl-3"-methoxybutyloxy)phenyl]pyrimidine (Compound No. 3) ##STR8##
0.07 g of 55% sodium hydride was dispersed in 2 ml of dimethylformamide (DMF) to obtain a dispersion. A solution of 0.45 g of (1"R,3"R)-2-(4'-n-octylphenyl)-5-[4'-(1"-methyl-3"-hydroxybutyloxy)phenyl]pyrimidine in 2 ml of DMF was dropwise added to the dispersion. The obtained mixture was stirred at a room temperature for one hour, followed by the dropwise addition thereto of a solution of 0.23 g of methyl iodide in 2 ml of DMF. The obtained mixture was further stirred at a room temperature for 2 hours, followed by the addition of water. The mixture was extracted with ethyl ether and the extract was purified by silica gel column chromatography using a n-hexane/ethyl acetate (85:15) mixture as a developing solvent to obtain 0.37 g of a white solid.
The infrared spectroscopic analysis of the solid revealed that the solid had the following characteristic absorptions and it was thus identified with the objective compound.
______________________________________2920 cm.sup.-1 (s), 2850 cm.sup.-1 (w), 1610 cm.sup.-1 (s),1580 cm.sup.-1 (w), 1530 cm.sup.-1 (w), 1510 cm.sup.-1 (m),1430 cm.sup.-1 (s), 1375 cm.sup.-1 (m), 1280 cm.sup.-1 (m),1245 cm.sup.-1 (s), 1180 cm.sup.-1 (m), 1090 cm.sup.-1 (m), 835 cm.sup.-1 (m), 795 cm.sup.-1 (w)______________________________________
The obtained compound was sandwitched between two glass plates and the phase of the compound was observed with a polarization microscope to ascertain the following phase transition: ##STR9##
EXAMPLE 4 (SYNTHESIS EXAMPLE 4)
Synthesis of (1"S,3"R)-2-(4'-n-octylphenyl)-5-[4'-(1"-methyl-3"-methoxybutyloxy)phenyl]pyrimidine (Compound No. 4) ##STR10##
The same procedure as that of Example 3 was repeated except that (1"S,3"R)-2-(4'-n-octylphenyl)-5-[4'-(1"-methyl-3"-hydroxybutyloxy)phenyl]pyrimidine was used to obtain a product.
The infrared spectroscopic analysis of the product revealed that the product had the following characteristic absorptions and it was thus identified with the objective compound:
______________________________________2920 cm.sup.-1 (s), 2850 cm.sup.-1 (w), 1610 cm.sup.-1 (s),1580 cm.sup.-1 (w), 1530 cm.sup.-1 (w), 1510 cm.sup.-1 (m),1430 cm.sup.-1 (s), 1375 cm.sup.-1 (m), 1280 cm.sup.-1 (m),1245 cm.sup.-1 (s), 1180 cm.sup.-1 (m), 1090 cm.sup.-1 (m), 835 cm.sup.-1 (m), 795 cm.sup.-1 (w)______________________________________
EXAMPLE 5 (SYNTHESIS EXAMPLE 5)
Synthesis of (1"R,3"S)-2-(4'-n-octylphenyl)-(1"-methyl-3"-hexyloxybutyloxy)phenyl]pyrimidine (Compound No. 5) ##STR11## 0.07 g of 55% sodium hydride was dispersed in 2ml of dimethylformamide (DMF) to obtain a dispersion. A solution of 0.45 g of (1"R,3"S)-2-(4'-n-octylphenyl)-(1"-methyl-3"-hydroxybutyloxy)phenyl]pyrimidine in 2 ml of DMF was dropwise added to the dispersion. The obtained mixture was stirred at a room temperature for one hour, followed by the dropwise addition thereto of a solution of 0.26 g of n-hexyl bromide in 2 ml of DMF. The obtained mixture was further stirred at 90° C. for 2 hours, followed by the addition of water. The obtained mixture was extracted with ethyl ether and the extract was dried and freed from the solvent. The residue was purified by silica gel column chromatography using a n-hexane/ethyl acetate (90:10) mixture as a developing solvent to obtain 0.14 g of a colorless viscous liquid.
The infrared spectroscopic analysis of the liquid revealed that the liquid had the following characteristic absorptions and it was thus identified with the objective compound:
______________________________________2925 cm.sup.-1 (s), 2860 cm.sup.-1 (m), 1650 cm.sup.-1 (m),1585 cm.sup.-1 (w), 1515 cm.sup.-1 (w), 1430 cm.sup.-1 (s),1375 cm.sup.-1 (w), 1285 cm.sup.-1 (w), 1250 cm.sup.-1 (s),1185 cm.sup.-1 (w), 1130 cm.sup.-1 (w), 1110 cm.sup.-1 (w), 835 cm.sup.-1 (w), 795 cm.sup.-1 (w)______________________________________
EXAMPLE 6 (SYNTHESIS EXAMPLE 6)
Synthesis of (1"R,3"R)-2-(4'-n-octylphenyl)-5-[4'-(1"-methyl-3"-phenoxybutyloxy)phenyl]pyrimidine (Compound No. 6) ##STR12##
0.45 g of (1"R,3"S)-2-(4'-n-octylphenyl)-5[4'-(1"-methyl-3"-hydroxybutyloxy)phenyl]pyrimidine, 0.11 g of phenol, 0.31 g of triphenylphosphine and 0.24 g of diisopropyl azodicarboxylate were dissolved in 5 ml of ethyl ether. The obtained solution was stirred at a room temperature for 3 hours. The triphenylphosphine oxide thus precipitated was filtered off and the filtrate was freed from the solvent. The residue was purified by silica gel column chromatography using a n-hexane/ethyl acetate (90:10) mixture as a developing solvent to obtain 0.20 g of a colorless liquid.
The infrared spectroscopic analysis of the liquid revealed that the liquid had the following characteristic absorptions and it was thus identified with the objective compound:
______________________________________2920 cm.sup.-1 (s), 2850 cm.sup.-1 (w), 1610 cm.sup.-1 (s),1585 cm.sup.-1 (m), 1515 cm.sup.-1 (m), 1495 cm.sup.-1 (m),1430 cm.sup.-1 (s), 1375 cm.sup.-1 (m), 1280 cm.sup.-1 (m),1240 cm.sup.-1 (s), 1180 cm.sup.-1 (m), 1110 cm.sup.-1 (m), 830 cm.sup.-1 (m), 790 cm.sup.-1 (w), 755 cm.sup.-1 (m), 695 cm.sup.-1 (w)______________________________________
EXAMPLE 7 (APPLICATION EXAMPLE 1)
In order to evaluate the effect the liquid crystal composition according to the present invention, the following four compounds were mixed with each other to obtain a matrix liquid crystal composition: ##STR13##
The above matrix liquid crystal composition was sandwitched between two glass plates and the phase of the composition was observed with a polarization microscope to ascertain the following phase transition: ##STR14##
90% by weight of the matrix liquid crystal composition was mixed with 10% by weight of each of the compounds of the present invention prepared in Examples 1 to 6 to obtain liquid crystal compositions. The phase transition temperatures of the liquid crystal compositions were determined by the use of a polarization microscope in a similar manner to that described above with respect to the matrix liquid crystal composition. Further, the liquid crystal compositions were each injected into a glass cell of 2-μm thickness which was fitted with a transparent electrode and the surface of which was coated with a polyimide orientation film subjected to the parallel orientation treatment by rubbing to obtain a liquid crystal display element. The liquid crystal display elements thus prepared were examined for the speed of response (Ps) at 30° C. by applying an electric field of ±15 V (60 Hz rectangular alternating current) thereto. Further, the spontaneous polarizations thereof were determined by the triangular wave method. The results are shown in Table 1.
TABLE 1__________________________________________________________________________ 30° C. τ PsNo. SmC* SmA N* Iso (μsec) (nC/cm.sup.2)__________________________________________________________________________Compound No. 1 • 45.6 • 53.5 • 63.0 • 110 +8.9Compound No. 2 • 45.6 • 53.5 • 63.0 • 110 -8.9Compound No. 3 • 48.4 • 55.8 • 64.5 • 125 +6.1Compound No. 4 • 48.4 • 55.8 • 64.5 • 125 -6.1Compound No. 5 • 47.7 • 56.5 • 63.4 • 172 +0.87Compound No. 6 • 41.3 • 51.7 • 62.2 • 308 +0.36__________________________________________________________________________
Conditions: The phase transition temperatures were each determined by polarization microscopy.
polyimide orientation film, cell thickness: 2 μm, application of ±15 V (60 Hz), Ps was determined by the triangular wave method.
It can be understood from the results shown in Table 1 that the optically active compound of the present invention induces an SmC* phase to bring about an extremely short response time and a large spontaneous polarization even when it is added to a matrix liquid crystal composition only in an amount of 10%.
EXAMPLE 8 (APPLICATION EXAMPLE 2)
Compositions obtained by adding 10 to 30% of a compound of the present invention represented by the formula which will be described below to the same matrix liquid crystal composition as that used in Example 7 were each examined for phase transition temperature, speed of response and change in spontaneous polarization. The results are shown in Table 2.
TABLE 2__________________________________________________________________________ ##STR15## 30° C. τ PsAmount SmC* SmA N* Iso (μsec) (nC/cm.sup.2)__________________________________________________________________________10% . 46 . 54 . 63 . 110 -8.920% . 43 . 47 . 60 . 80 -10.930% . 36 . -- . 56 . 80 -26.3__________________________________________________________________________
Conditions: The phase transition temperatures were each determined by polarization microscopy.
polyimide orientation film, cell thickness: 2 μm, application of ±15 V (60 Hz), Ps was determined by the triangular wave method.
Example 9 (APPLICATION EXAMPLE 3)
The same matrix liquid crystal composition (A) as that used in Example 7 was mixed with a chlorinated pyrimidine compound (B) represented by the formula which will be described below and the Compound No. 1 (C) prepared in Example 1 at a ratio as specified below to obtain a liquid crystal composition. The liquid crystal compositions thus prepared were each examined for phase transition temperatures, speed of response and change in spontaneous polarization. The results are shown in Table 3.
__________________________________________________________________________[Chlorinated pyrimidine compound] ##STR16##[Formulation]Compound A B C__________________________________________________________________________Ex. 9-1 60 parts 20 parts 20 parts 9-2 70 15 15 9-3 70 20 10 9-4 79 14 7Ref. Ex. 9-1 80 20 -- 9-2 90 10 --__________________________________________________________________________
TABLE 3______________________________________ 30° C. τ PsNo. SmC* SmA N* Iso (μsec) (nC/cm.sup.2)______________________________________Ex.9-1 • 55 • 66 • 70 • 79 +24.59-2 • 53 • 64 • 69 • 83 +11.59-3 • 58 • -- • 75 • 90 +21.89-4 • 53 • 67 • 70 • 78 +8.0Ref. Ex.9-1 • 58 • 75 • -- • 108 +5.29-2 • 52 • 68 • 71 • 165 +1.5______________________________________
Conditions: The phase transition temperatures were each determined by polarization microscopy.
polyimide orientation film, cell thickness: 2 μm, application of ±15 V (60 Hz), Ps was determined by the triangular wave method.
EXAMPLE 10 (APPLICATION EXAMPLE 4)
A liquid crystal composition comprising 70 parts of the same matrix liquid crystal composition as that used in Example 7, 15 parts of the same chlorinated pyrimidine compound as that used in Example 9 and 15 parts of the Compound No. 3 prepared in Example 3 exhibited the following phase transition temperatures: ##STR17##
The above liquid crystal composition was injected into a glass cell of 2-μm thickness which is fitted with a transparent electrode and the surface of which was coated with a polyimide orientation film subjected to the parallel orientation treatment by rubbing to obtain a liquid crystal display element. This liquid crystal display element was examined for speed of response (Ps) at 30° C. by applying an electric field of ±15 V (60 Hz rectangular alternating current) thereto. Further, the spontaneous polarization (τ) thereof was determined by the triangular wave method. The speed of response (Ps) was -11.1 nC/cm 2 and the spontaneous polarization (τ) was 106 μsec.
As shown in the foregoing Examples 7 to 10, when the compound of the present invention is added to a matrix liquid crystal having an SmC or SmC* phase, the compound imparts a large spontaneous polarization to the SmC or SmC* phase while scarcely lowering the transition temperature of the matrix crystal between SmA and SmC or SmC*, thus forming a chiral smectic C phase exhibiting a high-speed electric field response, though the compound does not exhibit any liquid crystal phase near room temperature.
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An optically active compound useful as a component of a ferroelectric liquid crystal composition represented by the following general formula (I) and a ferroelectric liquid crystal composition containing the same: ##STR1## wherein R stands for a C 1 ˜18 alkyl group; R' stands for a C 1 ˜18 alkyl group which may be substituted or an aryl group; X stands for ##STR2## or --O-- and an asterisk refers to an optically active carbon atom.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2014-145589 filed in Japan on Jul. 16, 2014, the entire contents of which are hereby incorporated by reference.
FIELD
[0002] The present invention relates to a lenticular lens sheet used in a display apparatus capable of displaying different images from a plurality of viewpoints, a display apparatus including the lenticular lens sheet and an electronic equipment including the display apparatus. In particular, the present invention relates to an alignment mark of a lenticular lens sheet.
BACKGROUND
[0003] A stereoscopic display apparatus using a display panel such as a liquid crystal panel having a plurality of pixels based on a glass substrate, an organic electroluminescence (EL) panel, plasma display panel (PDP), or the like, and a lenticular lens sheet has been proposed. In order to obtain high stereoscopic display characteristics in the stereoscopic display apparatus using a lenticular lens sheet, when bonding the lenticular lens sheet to a display panel, it is necessary to align the pixel of the display panel with the lens of the lenticular lens sheet with high accuracy. In order to align the display panel with the lenticular lens sheet with high accuracy, it is necessary to dispose alignment marks on at least two regions, with no mark similar to the alignment mark in the vicinity of each of the alignment marks, and more high visibility of the alignment mark is required.
[0004] In Japanese Patent Application Laid-Open No. 2008-070760 (hereinafter, referred to as Patent Document 1), as illustrated in FIG. 1 , a lenticular lens sheet 100 includes cylindrical lenses 101 and non-periodic flat parts 102 introduced parallel to an extending direction of the cylindrical lenses 101 , and the non-periodic flat parts 102 are made to serve as an alignment mark for an X-axis direction. Herein, X and Y arrows on a right side of FIG. 1 illustrate the X-axis direction and a Y-axis direction, respectively. FIG. 2 is an enlarged front view illustrating the alignment mark of the lenticular lens sheet 100 . The dot hatching regions of FIG. 2 represent portions having the surface formed in a curved surface.
[0005] When aligning the display panel with the lenticular lens sheet with high accuracy, generally, the alignment marks of the lenticular lens sheet 100 are observed by a charge coupled device (CCD) camera. In particular, when observing the alignment marks by epi-illumination light, since there is a difference in brightness or color enough to allow recognition of the non-periodic flat parts 102 and the cylindrical lens 101 , it is possible to recognize a boundary between the non-periodic flat part 102 and the cylindrical lens 101 by a simple image recognition device in a short time with high accuracy. The reason is that a lot of epi-illumination lights are reflected toward the CCD camera on a flat part, but the epi-illumination light reflected toward the CCD camera on the curved surface is decreased compared to the flat part.
[0006] Further, when observing the non-periodic flat part 102 , and a line of intersection between a surface of the non-periodic flat part 102 and a surface of the cylindrical lens 101 , it is possible to easily focus to the line of intersection between the non-periodic flat part 102 and the cylindrical lens 101 by the CCD camera using transmitted light and the epi-illumination light.
[0007] Japanese Patent Application Laid-Open No. 2011-232446 (hereinafter, referred to as Patent Document 2) discloses three methods relating to the alignment mark, which will be respectively described as Method A, Method B and Method C below.
[0008] In Method A of Patent Document 2, as illustrated in FIG. 3 , an X-direction cylindrical lens 104 having an extending direction perpendicular to the extending direction of Y-direction cylindrical lens 103 is introduced to a lenticular lens sheet 100 a including the Y-direction cylindrical lens 103 , and the X-direction cylindrical lens 104 is made to serve as an alignment mark. The X-direction cylindrical lens 104 has a smaller pitch and a smaller height of a lens than the Y-direction cylindrical lens 103 . The dot hatching regions of FIG. 3 represent portions having the surface formed in a curved surface. FIG. 4 is an enlarged perspective view illustrating the alignment mark of the lenticular lens sheet 100 a . FIG. 5 is a cross-sectional view illustrating the lenticular lens sheet 100 a taken on line A-A′ illustrated in FIG. 3 .
[0009] In Method B of Patent Document 2, as illustrated in FIG. 6 , an X-direction flat part 105 having an extending direction perpendicular to the extending direction of Y-direction cylindrical lens 103 is introduced to a lenticular lens sheet 100 b including the Y-direction cylindrical lens 103 , and the X-direction flat part 105 is made to serve as an alignment mark. The dot hatching regions of FIG. 6 represent portions having the surface formed in a curved surface. FIG. 7 is an enlarged perspective view illustrating the alignment mark of the lenticular lens sheet 100 b . FIG. 8 is a cross-sectional view illustrating the lenticular lens sheet 100 b taken on line B-B′ illustrated in FIG. 6 .
[0010] In Method C of Patent Document 2, as illustrated in FIG. 9 , an X-direction cylindrical lens 104 having an extending direction perpendicular to the extending direction of Y-direction cylindrical lens 103 is introduced to a lenticular lens sheet 100 c including the Y-direction cylindrical lens 103 . Further, a Y-direction cylindrical lens 103 a having an extending direction parallel to the extending direction of the Y-direction cylindrical lens 103 are introduced thereto. The X-direction cylindrical lens 104 and the Y-direction cylindrical lens 103 a have a smaller pitch and a smaller height of a lens than the Y-direction cylindrical lens 103 , respectively. The X-direction cylindrical lens 104 and the Y-direction cylindrical lens 103 a are made to serve as an alignment mark. The dot hatching regions of FIG. 9 represent portions having the surface formed in a curved surface. FIG. 10 is an enlarged perspective view illustrating a region in which the X-direction cylindrical lens 104 and the Y-direction cylindrical lens 103 a of the lenticular lens sheet 100 c are crossed with each other.
[0011] In a method disclosed in Japanese Patent Application Laid-Open No. 2009-115920 (hereinafter, referred to as Patent Document 3), as illustrated in FIG. 11 , a flat part 106 is introduced to a lenticular lens sheet 100 d including Y-direction cylindrical lens 103 . The flat part 106 is, unlike Patent Document 1, only partially formed, and is made to serve as an alignment mark. The dot hatching regions of FIG. 11 represent portions having the surface formed in a curved surface. FIG. 12 is an enlarged perspective view illustrating the alignment mark of the lenticular lens sheet 100 d.
[0012] In the respective Patent Documents 1 to 3, the alignment is performed using the alignment mark of the display panel and the alignment mark introduced to the lenticular lens sheet.
[0013] In Patent Documents 1 and 2, the lenticular lens sheets made of a resin having excellent cost performance are used in the stereoscopic display apparatus. However, in the lenticular lens sheet made of a resin, when the temperature of the display apparatus is increased, thermal expansion coefficients of the resin and the glass are different from each other by 10 times or more. Therefore, a pitch or a positional relationship between display pixels on the glass substrate and the lenses of the lenticular lens sheet is deviated from a design value, thereby causing a problem that the stereoscopic display fails. Therefore, a lenticular lens sheet having patterns of an ultraviolet curing resin prepared on one surface of the glass substrate has been considered. Since thermal expansion of the lenticular lens sheet using the glass substrate is suppressed to an extent equal to the glass substrate, the considered lenticular lens sheet becomes an effective countermeasure means with respect to the above-described problems.
[0014] In the lenticular lens sheet 100 of Patent Document 1, by observing the alignment mark by the CCD camera using epi-illumination light, it is possible to simply recognize the boundary between the non-periodic flat part 102 and the cylindrical lens 101 as illustrated in FIG. 2 , and perform the alignment in an X direction with high accuracy. However, the method of Patent Document 1 is effective in the X direction, but since there is no mark to be a reference of the Y direction, it is not possible to perform the alignment in the Y direction. Therefore, when the lenticular lens sheet 100 is adhered, in particular, to the display panel with a narrow frame, the lenticular lens sheet 100 may protrude from the display panel with respect to the Y-direction, which becomes a factor in terms of decreasing yields.
[0015] FIG. 13 is an enlarged front view illustrating the alignment mark of the lenticular lens sheet 100 a of Method A of Patent Document 2. The dot hatching regions of FIG. 13 represent portions having the surface formed in a curved surface. In the lenticular lens sheet 100 a of Method A of Patent Document 2, the surfaces of the Y-direction cylindrical lens 103 and the X-direction cylindrical lens 104 are curved surfaces. Accordingly, even when observing the alignment marks of the lenticular lens sheet 100 a by the CCD camera using the epi-illumination light, as illustrated in FIG. 13 , the Y-direction cylindrical lens 103 and the X-direction cylindrical lens 104 are seen at the same brightness and color as each other. Therefore, it is difficult to recognize the boundary between the Y-direction cylindrical lens 103 and the X-direction cylindrical lens 104 by a simple image recognition device in a short time with high accuracy. Also, it is difficult to focus to the line of intersection (for example, the line of intersection with the adjacent Y-direction cylindrical lens 103 ) between the curved surfaces by the CCD camera, compared to the case of focusing to the line of intersection between the flat part and the curved surface using the transmitted light and the epi-illumination light. That is, in the case of the line of intersection between the flat part and the curved surface, the flat part and the line of intersection are present on the same focus position as each other, such that it is possible to focus thereto using both thereof. Meanwhile, in the case of the line of intersection between the curved surfaces, it is necessary to focus only using the line of intersection. Further, since there are many boundaries between the Y-direction cylindrical lens 103 and the X-direction cylindrical lens 104 having the same shape as each other close thereto (boundaries having a similar boundary close thereto are surrounded by a triangle), it is difficult to determine a position of the boundary to which the observed boundary belongs. Accordingly, Method A of Patent Document 2 is insufficient as the alignment mark.
[0016] FIG. 14 is an enlarged front view illustrating the alignment mark of the lenticular lens sheet 100 b of Method B of Patent Document 2. The dot hatching regions of FIG. 14 represent portions having the surface formed in a curved surface. In the lenticular lens sheet 100 b of Method B of Patent Document 2, when observing the alignment mark by the CCD camera using the epi-illumination light, as illustrated in FIG. 14 , it is possible to recognize the boundary between the Y-direction cylindrical lens 103 and the X-direction flat part 105 by a simple image recognition device in a short time with high accuracy. However, since there are many boundaries between the Y-direction cylindrical lens 103 and the X-direction flat part 105 having the same shape as each other close thereto (boundaries having a similar boundary close thereto are surrounded by a triangle, similar to FIG. 13 ), it is difficult to determine a position of the boundary to which the observed boundary belongs. Accordingly, Method B of Patent Document 2 is also insufficient as the alignment mark.
[0017] FIG. 15 is an enlarged front view illustrating the alignment mark of the lenticular lens sheet 100 c of Method C of Patent Document 2. The dot hatching regions of FIG. 15 represent portions having the surface formed in a curved surface. In the lenticular lens sheet 100 c of Method C of Patent Document 2, as illustrated in FIG. 15 , since the boundaries between the Y-direction cylindrical lenses 103 and 103 a and the X-direction cylindrical lens 104 having boundaries with no similar boundary close thereto are present (portions surrounded by a circle in FIG. 15 ), it is possible to determine a position of the boundary to which the observed boundary belongs. However, as the surfaces of the Y-direction cylindrical lenses 103 and 103 a and the X-direction cylindrical lens 104 are the curved surfaces, it is difficult to recognize the boundary by a simple image recognition device in a short time. Further, it is difficult to focus to the line of intersection between the curved surfaces using the transmitted light and the epi-illumination light, compared to the case of focusing to the line of intersection between the flat part and the curved surface. Accordingly, Method C of Patent Document 2 is also insufficient as the alignment mark.
[0018] FIG. 16 is an enlarged front view illustrating the alignment mark of the lenticular lens sheet 100 d of Patent Document 3. The dot hatching regions of FIG. 16 represent portions having the surface formed in a curved surface. With the lenticular lens sheet 100 d of Patent Document 3, as illustrated in FIG. 16 , since the boundaries between the Y-direction cylindrical lens 103 and the flat part 106 having different shapes from each other are present (portions surrounded by a circle in FIG. 16 ), it is possible to determine a position of the boundary to which the observed boundary belongs. Further, when observing the alignment mark by the CCD camera using the epi-illumination light, as illustrated in FIG. 16 , it is possible to recognize the boundary between the Y-direction cylindrical lens 103 and the flat part 106 by a simple image recognition device in a short time with high accuracy. However, it is generally difficult to process the boundary between the Y-direction cylindrical lens 103 and the flat part 106 in the Y direction in a shape so as to be abruptly changed from the cylindrical lens to the flat part, as the lenticular lens sheet 100 d of Patent Document 3. Reasons therefor will be described below.
[0019] In general, when preparing a lenticular lens sheet at a low cost, a method of transferring the shape of a mold to a resin is used. In order to prepare the lenticular lens sheet 100 d , a mold having a shape in which the lenticular lens sheet 100 d is inverted is required.
[0020] FIGS. 17 and 18 illustrate perspective views illustrating molds necessary for preparing the lenticular lens sheet 100 d of Patent Document 3. FIG. 17 is a perspective view illustrating a mold having an ideal shape, but difficult to process at a low cost, and FIG. 18 is a perspective view illustrating a mold capable of being processed at a low cost, but having a practical shape (also referred to as a non-ideal shape). Herein, the mold of FIG. 17 corresponds to FIG. 12 . FIG. 19 is a cross-sectional view taken on line C-C′ illustrating a fabrication process of the mold of FIG. 18 , and the dot hatching region of FIG. 19 represents a portion having the surface formed in a curved surface.
[0021] As illustrated in FIG. 19 , in order to form a prescribed lens pattern on the mold, a concave cylindrical lens forming part 103 b is cut out in the mold by a tool bit (cutting tool) 107 having a cross-section formed in a U shape in the X direction. In order to protect the tool bit 107 , it is necessary to move the tool bit 107 up and down at a gentle angle with respect to a processing surface, while not allowing the tool bit to vertically move up and down from the mold at the beginning and ending of the cutting of the cylindrical lens forming part 103 b . Thereby, the boundary between the Y-direction cylindrical lens forming part 103 b and a flat-part forming part 106 b in the Y direction is gradually changed from the cylindrical lens to the flat part, as illustrated in FIG. 18 . In FIGS. 17 and 18 , to highlight this change, a side wall surface is illustrated by a slant-hatching. Further, the line of intersection between the flat-part forming part 106 b and a curved surface which can be formed during removing the tool bit 107 is formed in a curved line (i.e., the external form of the flat-part forming part 106 b is not formed in a rectangular shape).
[0022] A process of forming the curved line will be described with reference to FIG. 19 , which is a cross-sectional view illustrating the mold 108 during processing along line C-C′ of FIG. 18 . FIG. 19 illustrates a state in which cutting of the Y-direction cylindrical lens forming part 103 b in the mold 108 by the tool bit 107 begins, and is a view illustrating a process in which the tool bit 107 is inserted into the mold 108 to a processing position of the Y-direction cylindrical lens forming part 103 b . The Y-direction cylindrical lens forming part 103 b illustrated in FIG. 19 represents before processing, and a dotted line represents a trajectory of a cutting edge of the tool bit 107 to be processed. As illustrated in FIG. 19 , in order to protect the tool bit 107 , the tool bit 107 moves in a processing direction while gradually descending, and the tool bit 107 is inserted into the mold 108 at a gentle angle. When ending the cutting of the mold 108 by the tool bit 107 , the operation is performed in a reverse procedure to at the time of insertion. By beginning and ending of the cutting, a processing area due to the up and down movement of the tool bit 107 is formed in a curved line as illustrated in FIG. 18 . In addition, since accuracy of the mold processing may be decreased during ascending and descending of the tool bit 107 , the shape of the curved line as illustrated in FIG. 18 prepared by this process becomes unstable.
[0023] Moreover, in the case of a shape in which the boundary between the Y-direction cylindrical lens forming part 103 b and the flat-part forming part 106 b in the Y direction is rapidly changed such as an ideal mold illustrated in FIG. 17 , there is a need to replace the tool bit depending on the shape, maintain the tool bit with high accuracy during replacing, and cope with a high load of the tool bit, and thereby it is difficult to process the mold at a low cost.
[0024] FIG. 20 is a perspective view illustrating the lenticular lens sheet prepared by the mold of FIG. 18 having a practical shape capable of being processed at a low cost based on Patent Document 3. FIG. 21 is a front view illustrating the lenticular lens sheet of FIG. 20 . A slant-hatching region of FIG. 20 represents a portion corresponding to a side wall surface of the mold, and dot hatching regions of FIG. 21 represent portions having the surface formed in a curved surface. As illustrated in FIG. 21 , the boundaries between the Y-direction cylindrical lens 103 and the flat part 106 a having different shapes from each other are present, however, since curved lines 109 have an unstable shape due to the processing during an ascending and descending of the tool bit as described above, there is a case in which the boundary present therebetween cannot be recognized by a simple image recognition device in a short time with high accuracy. Accordingly, Patent Document 3 is also insufficient as the alignment mark.
[0025] In addition, an intersecting part between the Y-direction cylindrical lens 103 and the X-direction cylindrical lens 104 in FIG. 4 of Patent Document 2, an intersecting part between the Y-direction cylindrical lens 103 and the X-direction flat part 105 in FIG. 7 , an intersecting part between the Y-direction cylindrical lens 103 and the X-direction cylindrical lens 104 in FIG. 10 , and an intersecting part between the Y-direction cylindrical lens 103 a and the X-direction cylindrical lens 104 are also difficult to be processed by the mold at a low cost as similar to Patent Document 3.
[0026] In the conventional method illustrated in Patent Documents 1 to 3, it is difficult to align the lenticular lens sheet with the display panel at a low cost with high accuracy, and bond to each other.
[0027] Further, in the lenticular lens sheet having patterns of an ultraviolet curing resin prepared on one surface of the glass substrate, since a hard lenticular lens sheet is bonded to a hard display panel, an alignment mark capable of allowing recognition in a short time with high accuracy is required, compared to the case in which the lenticular lens sheet made of a soft resin is bonded to the hard display panel.
[0028] More specifically, when bonding the lenticular lens sheet made of a soft resin to the hard display panel, the display panel is fixed on a stage, and the lenticular lens sheet is bent and gradually bonded to the display panel from one side thereof, while aligning the alignment mark of the lenticular lens sheet with the alignment mark of the display panel. Thereby, it is possible to bond the lenticular lens sheet to the display panel without forming a bubble even in the atmosphere.
[0029] Meanwhile, when bonding the hard lenticular lens sheet to the hard display panel, since it is not possible to bend the lenticular lens sheet as the lenticular lens sheet made of a resin, the lenticular lens sheet is also fixed to a different stage, in addition to fixing of the display panel to the stage. Next, in order to measure the position of the display panel on the stage and the position of the lenticular lens sheet, the position of the alignment mark is measured. Then, by using the alignment marks, the lenticular lens sheet and the display panel are bonded to each other by aligning the same with high accuracy in a vacuum. In this case, since it is necessary to align the alignment mark in the Y direction in addition to the X direction, the lenticular lens sheet requires the alignment marks capable of allowing recognition of the positions thereof in the X and Y directions by a simple image recognition device in a short time with high accuracy.
SUMMARY
[0030] In consideration of the above-mentioned circumstances, it is a major object of the present invention to provide a lenticular lens sheet capable of simultaneously achieving an improvement in visibility due to improving bonding accuracy, and low cost due to shape stabilization during processing the lens, a display apparatus and an electronic equipment including the same.
[0031] More specifically, another object of the present invention is to provide a lenticular lens sheet capable of being aligned in a Y direction with high accuracy, in addition to the highly accurate alignment in an X direction. Another object of the present invention is to provide a lenticular lens sheet capable of allowing recognition of an alignment mark by a simple image recognition device in a short time with high accuracy. Further, another object of the present invention is to provide a lenticular lens sheet allowing a simple determination of a position at which the observed alignment mark is disposed. Further, another object of the present invention is to provide a lenticular lens sheet which is able to be prepared by a mold having a practical shape capable of being processed at a low cost. Furthermore, another object of the present invention is to provide a lenticular lens sheet which is able to be, even when an optical member is made of a glass substrate, bonded to the display panel by aligning with the same.
[0032] According to one aspect of the present invention, there is provided a lenticular lens sheet, including: a plurality of cylindrical lenses which extend in a direction parallel to each other; and an alignment mark which has two cylindrical lenses among the plurality of cylindrical lenses, a flat part disposed between the two cylindrical lenses, and a structure which is disposed on the flat part and extends between the two cylindrical lenses.
[0033] According to the present invention, since the boundaries, which are formed by two cylindrical lenses having the extending direction parallel to each other, the flat part disposed between the two cylindrical lenses, and the structure extending between the two cylindrical lenses on the flat part, and have different shapes from each other, are present, it is possible to determine a position of the boundary to which the observed boundary belongs. In addition, the surfaces of the two cylindrical lenses are curved surfaces, and at least a surface contacting the flat part of the structure connecting the two cylindrical lenses is also the curved surface or inclined surface. Therefore, the flat part has a difference in brightness or color enough to allow recognition of the surface contacting the two cylindrical lenses and the structure, such that the boundaries between the flat part and the two cylindrical lenses can be recognized by a simple image recognition device in a short time with high accuracy.
[0034] In the lenticular lens sheet according to the present invention, the structure may be any one of the cylindrical lens, a hexahedron, and a prism.
[0035] According to the present invention, it is possible to easily process the alignment mark in the mold for preparing the lenticular lens sheet at a low cost.
[0036] In the lenticular lens sheet according to the present invention, the structure may intersect the flat part in two straight lines, and the two straight lines may be parallel to each other.
[0037] The configurational characteristic in which the structure intersects the flat part in two straight lines, and the two straight lines are parallel to each other means that the structure of the region on the flat part is processed in the preparing step of the mold for preparing the lenticular lens sheet without ascending and descending the tool bit. Briefly, the processed shape such as the curved line of Method C of Patent Document 2 is unstable, whereas the shape of the structure of the present invention is stable.
[0038] In the lenticular lens sheet according to the present invention, the flat part may extend in the extending direction of the cylindrical lens. In the lenticular lens sheet according to the present invention, the flat part may be present only near the structure.
[0039] According to the present invention, the flat part is present in the extending direction of the cylindrical lens, and further, the flat part forms the alignment mark of the present invention. According to the present invention, the flat part is present only near the structure, and further, the flat part forms the alignment mark of the present invention. Since the flat part is formed on only a region requiring the alignment mark, and the other regions can be formed as the cylindrical lens, there is an effect of widening the area of the cylindrical lens.
[0040] In the lenticular lens sheet according to the present invention, one alignment mark may be provided on the same flat part.
[0041] According to the present invention, even when only one alignment mark is provided on the same flat part, the alignment can be performed with high accuracy.
[0042] In the lenticular lens sheet according to the present invention, the extending direction of the cylindrical lens may be inclined with respect to sides forming an external form of the lenticular lens sheet.
[0043] The cylindrical lens whose extending direction is inclined is referred to as an oblique cylindrical lens. The present invention may also be applied to the alignment mark on the lenticular lens sheet of the oblique cylindrical lens.
[0044] In the lenticular lens sheet according to the present invention, the cylindrical lens may have a lower surface formed in a flat surface and an upper surface formed in a convex surface, and the structure has a lower height than the height of the cylindrical lens based on the lower surface.
[0045] According to the present invention, when two alignment marks are provided on the same flat part, even if a protection film is bonded to the surface of the lenticular lens sheet for preventing scratches or contamination, a gap can be maintained between the structure and the protection film. Accordingly, even when the pressure in an environment is reduced while the protection film is bonded to the lenticular lens sheet, air can escape through a leakage path, and peeling-off of the protection film can be prevented due to the pressure of the air trapped therein.
[0046] In the lenticular lens sheet according to the present invention, two or more alignment marks may be provided on the lenticular lens sheet.
[0047] According to the present invention, by using the two or more alignment marks provided on the lenticular lens sheet, it is possible to align the X and Y directions with high accuracy.
[0048] In the lenticular lens sheet according to the present invention, the cylindrical lens may be provided on a glass substrate.
[0049] According to the present invention, since it is possible to cope with the highly accurate alignment of the hard lens with the hard display panel, the present invention can be used for the lenticular lens sheet having patterns of a resin prepared on one surface of the glass substrate.
[0050] According to another aspect of the present invention, there is provided a display apparatus, including: a display panel; and the lenticular lens sheet according to the present invention, which is attached to the display panel. The display apparatus according to the present invention may further include a protection film which is attached to an upper surface of the lenticular lens sheet.
[0051] According to another aspect of the present invention, there is provided an electronic equipment, including: the display apparatus according to the present invention.
[0052] The alignment mark on the lenticular lens sheet of the present invention can be recognized by a simple image recognition device in a short time with high accuracy. Accordingly, when bonding the lenticular lens sheet on the display panel, by using the two or more alignment marks provided on the lenticular lens sheet, the X and Y directions, as well as θ rotation can be aligned in a short time with high accuracy, thereby improving productivity.
[0053] Furthermore, since the alignment mark of the present invention can be stably processed without increasing costs, the alignment mark is read during aligning at a high speed with high accuracy.
[0054] Furthermore, according to the present invention, since the flat part is formed on only a region requiring the alignment mark, and the other regions are the lens, an area that can be set in the display area is not greatly reduced. In particular, this effect is significantly large in the lenticular lens sheet of the oblique lens, and the present invention may also be applied to the lenticular lens sheet of the oblique lens.
[0055] Furthermore, according to the present invention, since the leakage path is formed even when the protection film is bonded by reducing the height of the structure, the protection film is not swollen or peeled off even under a reduced pressure. Accordingly, since the bonding process of the lenticular lens sheet to the display panel is performed while the protection film is bonded to the lenticular lens sheet, it is possible to prevent the lens from being scratched or stained in this process, and thereby improving the yield.
[0056] Furthermore, since the present invention may also be applied to the lenticular lens sheet having patterns of a resin prepared on one surface of the glass substrate, it is possible to supply a stereoscopic display apparatus which has almost no dependency on a temperature such that stereoscopic display can be performed even when the temperature of the display apparatus is increased.
[0057] The above and further objects and features of the invention will be more fully apparent from the following detailed description with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0058] FIG. 1 is a perspective view illustrating a lenticular lens sheet of Patent Document 1;
[0059] FIG. 2 is an enlarged front view illustrating an alignment mark on the lenticular lens sheet of Patent Document 1;
[0060] FIG. 3 is a front view illustrating a lenticular lens sheet in Method A of Patent Document 2;
[0061] FIG. 4 is an enlarged perspective view illustrating an alignment mark of the lenticular lens sheet in Method A of Patent Document 2;
[0062] FIG. 5 is a cross-sectional view illustrating the lenticular lens sheet in Method A of Patent Document 2 taken on line A-A′ illustrated in FIG. 3 ;
[0063] FIG. 6 is a front view illustrating the lenticular lens sheet in Method B of Patent Document 2;
[0064] FIG. 7 is an enlarged perspective view illustrating the alignment mark of the lenticular lens sheet in Method B of Patent Document 2;
[0065] FIG. 8 is a cross-sectional view illustrating the lenticular lens sheet in Method B of Patent Document 2 taken on line B-B′ illustrated in FIG. 6 ;
[0066] FIG. 9 is a front view illustrating the lenticular lens sheet in Method C of Patent Document 2;
[0067] FIG. 10 is an enlarged perspective view illustrating the alignment mark of the lenticular lens sheet in Method C of Patent Document 2;
[0068] FIG. 11 is a front view illustrating a lenticular lens sheet of Patent Document 3;
[0069] FIG. 12 is an enlarged perspective view illustrating an alignment mark on the lenticular lens sheet of Patent Document 3;
[0070] FIG. 13 is an enlarged front view illustrating the alignment mark of the lenticular lens sheet in Method A of Patent Document 2;
[0071] FIG. 14 is an enlarged front view illustrating the alignment mark of the lenticular lens sheet in Method B of Patent Document 2;
[0072] FIG. 15 is an enlarged front view illustrating the alignment mark of the lenticular lens sheet in Method C of Patent Document 2;
[0073] FIG. 16 is an enlarged front view illustrating the alignment mark on the lenticular lens sheet of Patent Document 3;
[0074] FIG. 17 is a perspective view illustrating a mold (mold having an ideal shape but difficult to process at a low cost) used for preparing the lenticular lens sheet of Patent Document 3;
[0075] FIG. 18 is a perspective view illustrating a mold (mold having a practical shape capable of being processed at a low cost) used for preparing the lenticular lens sheet of Patent Document 3;
[0076] FIG. 19 is a cross-sectional view illustrating a fabrication process of the mold taken on line C-C′ of FIG. 18 ;
[0077] FIG. 20 is a perspective view illustrating the lenticular lens sheet prepared by the mold having a practical shape capable of being processed at a low cost of FIG. 18 based on Patent Document 3;
[0078] FIG. 21 is a front view illustrating the lenticular lens sheet of FIG. 20 ;
[0079] FIG. 22 is a front view illustrating a lenticular lens sheet of a first embodiment;
[0080] FIG. 23A is an enlarged front view illustrating an alignment mark on the lenticular lens sheet of the first embodiment;
[0081] FIG. 23B is an enlarged perspective view illustrating the alignment mark on the lenticular lens sheet of the first embodiment;
[0082] FIG. 24A is a front view illustrating another lenticular lens sheet of the first embodiment;
[0083] FIG. 24B is a front view illustrating another lenticular lens sheet of the first embodiment;
[0084] FIG. 24C is a front view illustrating another lenticular lens sheet of the first embodiment;
[0085] FIG. 24D is a front view illustrating another lenticular lens sheet of the first embodiment;
[0086] FIG. 25A is a perspective view illustrating a method of manufacturing a mold required to prepare the lenticular lens sheet of the first embodiment;
[0087] FIG. 25B is a perspective view illustrating a method of manufacturing the mold required to prepare the lenticular lens sheet of the first embodiment;
[0088] FIG. 26 is a cross-sectional view illustrating the mold taken on line D-D′ of FIG. 25B ;
[0089] FIG. 27A is perspective views illustrating a structure of the lenticular lens sheet of the first embodiment;
[0090] FIG. 27B is perspective views illustrating a structure of the lenticular lens sheet of the first embodiment;
[0091] FIG. 27C is perspective views illustrating a structure of the lenticular lens sheet of the first embodiment;
[0092] FIG. 28 is an enlarged perspective view illustrating an alignment mark of another lenticular lens sheet of the first embodiment;
[0093] FIG. 29 is a perspective view illustrating another alignment method of the lenticular lens sheet with a display panel;
[0094] FIG. 30 is a front view illustrating a lenticular lens sheet of a second embodiment;
[0095] FIG. 31 is a view in which an area that can be set in a display area is added to the front view illustrating the lenticular lens sheet of FIG. 30 ;
[0096] FIG. 32 is a front view illustrating the lenticular lens sheet of an oblique lens of the second embodiment;
[0097] FIG. 33A is a view in which the area that can be set in the display area is added to the front view illustrating the oblique lenticular lens sheet;
[0098] FIG. 33B is a view in which the area that can be set in the display area is added to the front view illustrating the oblique lenticular lens sheet;
[0099] FIG. 34 is a front view illustrating the lenticular lens sheet using an oblique cylindrical lens applied with the configuration of the first embodiment;
[0100] FIG. 35A is a perspective view illustrating a method of manufacturing a mold required to prepare the lenticular lens sheet of the second embodiment;
[0101] FIG. 35B is a perspective view illustrating a method of manufacturing the mold required to prepare the lenticular lens sheet of the second embodiment;
[0102] FIG. 36 is a front view illustrating a lenticular lens sheet of a third embodiment;
[0103] FIG. 37 is a cross-sectional view illustrating the lenticular lens sheet of the third embodiment taken on line of D-D′ illustrated in FIG. 36 ;
[0104] FIG. 38 is an enlarged front view illustrating the alignment mark on the lenticular lens sheet of the third embodiment;
[0105] FIG. 39 is a cross-sectional view illustrating the lenticular lens sheet of the third embodiment after a protection film sheet is bonded to the lenticular lens sheet taken on line E-E′ illustrated in FIG. 38 ;
[0106] FIG. 40 is an enlarged view illustrating the alignment mark when the height of the structure and the height of the Y-direction cylindrical lens are substantially the same as each other;
[0107] FIG. 41 is a cross-sectional view illustrating the alignment mark after the protection film sheet is bonded to the lenticular lens sheet taken on line F-F′ illustrated in FIG. 40 ;
[0108] FIG. 42 is a cross-sectional view illustrating a stereoscopic display apparatus of a fourth embodiment;
[0109] FIG. 43 is a cross-sectional view illustrating another stereoscopic display apparatus of the fourth embodiment;
[0110] FIG. 44A is a perspective view illustrating a first example of an electronic equipment to which the stereoscopic display apparatus of the fourth embodiment may be applied;
[0111] FIG. 44B is a perspective view illustrating a second example of the electronic equipment to which the stereoscopic display apparatus of the fourth embodiment may be applied; and
[0112] FIG. 44C is a perspective view illustrating a third example of the electronic equipment to which the stereoscopic display apparatus of the fourth embodiment may be applied.
DETAILED DESCRIPTION
[0113] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
First Embodiment
[0114] First, a first embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 22 is a front view illustrating a lenticular lens sheet 8 of a first embodiment. In addition, FIGS. 23A and 23B illustrate alignment marks of the lenticular lens sheet 8 of the first embodiment, wherein FIG. 23A is an enlarged front view, and FIG. 23B is an enlarged perspective view. Dot hatching regions of FIGS. 22 and 23A represent portions having the surface formed in a curved surface.
[0115] In the first embodiment, as illustrated in FIG. 22 , the lenticular lens sheet 8 having a plurality of Y-direction cylindrical lenses 1 substantially parallel to each other in the Y direction has alignment marks 29 a to 29 d including two Y-direction cylindrical lenses 1 among the plurality of Y-direction cylindrical lenses, flat parts 2 disposed between the two Y-direction cylindrical lenses 1 , and structures 3 which are provided on the flat parts 2 and extend between the two Y-direction cylindrical lenses 1 (i.e., connect the two Y-direction cylindrical lenses 1 ). In FIGS. 22 , 23 A and 23 B, the structures 3 are X-direction cylindrical lenses substantially parallel to each other in an X-direction.
[0116] As illustrated in FIG. 23B , in the first embodiment, the surfaces of the Y-direction cylindrical lens 1 and the structure 3 are curved surfaces. Accordingly, when observing an alignment mark of the lenticular lens sheet 8 by a CCD camera using epi-illumination light, the Y-direction cylindrical lens 1 and the structure 3 are seen at the same brightness and color as each other, but the flat part 2 is seen at brightness and color enough to be recognized. Therefore, the boundaries between the Y-direction cylindrical lens 1 and the flat part 2 , and between the structure 3 and the flat part 2 can be recognized by a simple image recognition device in a short time with high accuracy. For example, results of experiments by the inventors, when the Y-direction cylindrical lens 1 and the structure 3 having RGB values of 100, 100 and 93, the flat part 2 had RGB values of 152, 153 and 145. Herein, the respective RGB values range from 0 to 255. In a CCD camera observation using the transmitted light and the epi-illumination light, since the flat part, and a line of intersection between the flat part and the curved surface are present on the same focus position, and focusing can be performed using both thereof, it is easy to perform the focusing. Further, in the CCD camera observation using the transmitted light and the epi-illumination light, the boundaries between the Y-direction cylindrical lens 1 and the flat part 2 , and between the structure 3 and the flat part 2 have no boundary (similar boundary) having the same shape as each other close thereto, thereby only a boundary region aimed at can be recognized by a simple image recognition device in a short time with high accuracy.
[0117] In addition, when the coordinates of two or more, preferably three or more alignment marks among the alignment marks 29 a to 29 d at four corners of the lenticular lens sheet 8 in FIG. 22 may be identified, high accurate alignment can be achieved.
[0118] First, an example of using two alignment marks will be described. For example, as illustrated in FIG. 24A , the highly accurate alignment in X direction and the highly accurate alignment in Y direction can be achieved by coordinates of the alignment marks 29 a and 29 b . Similarly, the highly accurate alignment using the alignment marks 29 c and 29 d which are disposed at an interval in the X direction can be achieved. Also, a combination of the alignment marks 29 a and 29 d which are disposed at intervals in the X and Y directions (see FIG. 24B ), or a combination of the alignment marks 29 b and 29 c also enable the highly accurate alignment. Further, preparation of the alignment mark which is not used for the alignment may be omitted, as illustrated in FIGS. 24A and 24B .
[0119] When the dimensions of the lenticular lens sheet 8 are made according to a design value, a combination of the alignment marks 29 a and 29 c which are disposed at an interval in the Y direction (see FIG. 24C ), or a combination of the alignment marks 29 b and 29 d also enable the highly accurate alignment. However, since there is no means for correcting the misalignment in the X direction, when the dimensions of the lenticular lens sheet 8 in the X direction are contracted or expanded from the design value, the magnitude of a shift is different from each other depending on the location. For example, when the position in the X direction is aligned at the position of the alignment mark 29 a without shift, the shift may be increased as separated from the position of the alignment mark 29 a in the X direction. Meanwhile, in the combination of the alignment marks 29 a and 29 b (see FIG. 24A ), even when the dimensions of the lenticular lens sheet 8 in the X direction are contracted or expended from the design value, it is possible to align so that the misalignment in the X direction at the alignment mark 29 a and the misalignment in the X direction at the alignment mark 29 b are minimized.
[0120] In the example using four alignment marks ( 29 a , 29 b , 29 c and 29 d ) ( FIG. 22 ), even when the dimensions of the lenticular lens sheet 8 are contracted and expanded not only in the X direction but also in the Y direction, it is possible to align so that misalignments in the X and Y directions at the positions of the four alignment marks are minimized. Therefore, when using the four alignment marks, it is possible to align with high accuracy, regardless of the dimensional accuracy of the lenticular lens sheet. In the case of aligning using three alignment marks, alignment accuracy may be decreased compared to the case of using the four alignment marks, but it is possible to align with a higher accuracy than the case of using the two alignment marks.
[0121] At the time of identifying the coordinates of the alignment marks, the coordinate of at least one boundary among four boundaries surrounded by a circle in FIG. 23A may be established per one alignment mark. In addition, when aligning using the two alignment marks, instead of the alignment marks at four corners, alignment marks 29 e and 29 f , which are disposed in the center of the flat part 2 in the Y direction as illustrated in FIG. 24D , may be used.
[0122] By using the alignment mark on the lenticular lens sheet 8 of the first embodiment, in a method of fixing the lenticular lens sheet on a stage, it is possible to be bonded to the display panel by aligning with high accuracy. In particular, when observing the alignment mark by the CCD camera using the epi-illumination light, even when using an opaque material such as stainless steel for the stage, unlike the CCD camera observation using the transmitted light, there is no need to make a hole for lighting in the stage, such that the alignment mark can be easily observed. Meanwhile, when observing using the transmitted light, if the size of the lenticular lens sheet is changed, it is necessary to align the holes for lighting formed in the stage, and there may be a case of requiring replacement of the stage. In this case, the replacement of the stage takes time due to the attachment accuracy being important, and this becomes a factor of decreasing productivity. However, when observing the alignment mark by the CCD camera using the epi-illumination light, such problems may not occur.
[0123] The lenticular lens sheet 8 of the first embodiment may be manufactured, for example, by transferring the shape of a mold 27 illustrated in FIGS. 25A and 25B to a resin. A method of manufacturing the mold 27 will be described using FIGS. 25A and 25B . As illustrated in FIG. 25A , leaving a flat-part forming part 2 a , cylindrical lens forming parts 1 a are formed in the mold 27 . Then, as illustrated in FIG. 25B , a structure forming part 3 a is formed from one cylindrical lens forming part 1 a to the other cylindrical lens forming part 1 a which face to each other with the flat-part forming part 2 a interposed therebetween by penetrating the flat-part forming part 2 a . Further, for clarity of the processed shape, slant-hatchings are added to the cut portions of the cylindrical lens forming part 1 a in FIG. 25B .
[0124] FIG. 26 illustrates a cross-sectional view taken on line D-D′ of FIG. 25B . As illustrated in FIG. 26 , the area of the flat-part forming part 2 a may be processed without the ascending and descending processes of a tool bit 25 , thereby the processed shape is stabilized. The processing accompanying the ascending and descending processes of the tool bit 25 which may cause an unstable processed shape, that is, the movement of the tool bit 25 up and down is performed in the area of the cylindrical lens forming part 1 a , such that the shapes of the boundaries between the Y-direction cylindrical lens 1 and the flat part 2 , and between the structure 3 and the flat part 2 are not affected. That is, since the mold required for preparing the lenticular lens sheet of the first embodiment does not need a special processing, the fabrication cost of the mold 27 is not substantially changed, compared to the case of not making the structure 3 . Further, a trajectory 26 of a cutting edge of the tool bit 25 is illustrated in FIG. 26 .
[0125] In addition, the processing is performed in the area of the flat-part forming part 2 a while not ascending and descending the tool bit 25 , the structure 3 intersects the flat part 2 in two straight lines, and the two straight lines are parallel to each other.
[0126] As the structure 3 , in addition to the cylindrical lens 3 c as illustrated in FIG. 27A , a hexahedron 3 d as illustrated in FIG. 27B , a prism 3 e as illustrated in FIG. 27C , or the like may be used. In the case of the hexahedron 3 d , sides in contact with the flat part 2 are formed in an inclined surface having a taper. The surfaces of the prism 3 e are formed in an inclined surface. Accordingly, when observing by the CCD camera using the epi-illumination light, since the inclined surfaces of the flat part 2 and the structure 3 have different brightness and color enough to be recognized from each other, the boundaries between the Y-direction cylindrical lens 1 and the flat part 2 , and between the structure 3 and the flat part 2 can be recognized by a simple image recognition device in a short time with high accuracy.
[0127] In the first embodiment of the present invention, in order to simplify the description, the lenticular lens sheet 8 including the Y-direction cylindrical lens 1 is exemplified, but the lenticular lens sheet including the X-direction cylindrical lens may also be employed. In this case, the structure 3 may be a cylindrical lens extending in the Y direction, the hexahedron, the prism or the like.
[0128] Moreover, the lenticular lens sheet 8 of the first embodiment is formed in an integral type in which the Y-direction cylindrical lenses 1 , the structures 3 and the sheet are made of the same material as each other as illustrated in FIG. 24 , but the lenticular lens sheet 8 a may be formed by disposing the Y-direction cylindrical lens 1 made of a resin 13 and the structure 3 on the substrate such as a glass substrate 12 as illustrated in FIG. 28 .
[0129] A method of manufacturing the lenticular lens sheet 8 a illustrated in FIG. 28 will be described. First, a resin 13 is applied on the glass substrate 12 in an appropriate amount. Then, a pre-processed shape of the mold 27 is transferred to the applied resin 13 . When using an ultraviolet curable resin, the resin 13 is cured by irradiating with ultraviolet rays. Thereafter, the mold 27 is removed, and the cured resin is cut into a predetermined size to complete the lenticular lens sheet 8 a.
[0130] In addition, as illustrated in FIG. 29 , the shape of the alignment mark on the lenticular lens sheet 8 a of the first embodiment and the shape of the alignment mark 9 a on a display panel 9 are simultaneously observed by the CCD camera to align the same with high accuracy, such that the lenticular lens sheet 8 a may be bonded to the display panel 9 . In FIG. 29 , the lenticular lens sheet 8 a in which the cylindrical lens is prepared of the resin 13 on the glass substrate 12 of FIG. 28 is described as an example, but it may be applied to the integral lenticular lens sheet 8 as illustrated in FIG. 24 .
Second Embodiment
[0131] In the first embodiment, as illustrated in FIG. 22 , only the structures 3 forming the alignment marks are present in the direction parallel to the extending direction of the Y-direction cylindrical lenses 1 of the flat parts 2 . The second embodiment is different from the first embodiment in that, as illustrated in FIG. 30 , the structure 3 and the Y-direction cylindrical lenses 1 forming the alignment marks are present in a direction parallel to the extending direction of the Y-direction cylindrical lenses 1 of the flat parts 2 , in other words, the flat parts 2 are present only near the structures 3 . Except this difference, the second embodiment can obtain the same effects as the first embodiment.
[0132] In the second embodiment, similar to the first embodiment, two or more, and preferably, three or more alignment marks among the alignment marks at four corners of the lenticular lens sheet are prepared, thereby the high accurate alignment can be achieved. FIG. 30 illustrates an example in which the alignment marks are prepared at the four corners of the lenticular lens sheet 8 b.
[0133] FIG. 30 illustrates an example in which the alignment mark 29 a and alignment mark 29 c are provided on the extending direction of the Y-direction cylindrical lenses 1 adjacent to each other, but the alignment mark 29 a and the alignment mark 29 c may be provided on the extending direction of the Y-direction cylindrical lenses 1 further separated from each other. In these cases, one alignment mark is provided on the extension of the same flat part 2 . Alternately, the alignment mark 29 a and the alignment mark 29 c may be provided on the extending direction of the same Y-direction cylindrical lens 1 . In all the cases, by comparing the practical coordinates of the alignment marks with the design coordinates of the alignment marks, high accurate alignment can be achieved. By the configuration of the second embodiment, it is possible to reduce the flat part 2 which does not contribute to the stereoscopic image display, such that, as compared to the first embodiment, as illustrated in FIG. 31 , an area 4 a that can be set in a display area may be expanded.
[0134] In addition, in the second embodiment, as illustrated in FIG. 32 , the present invention may also be applied to a lenticular lens sheet 8 c including oblique cylindrical lenses 28 whose extending direction is inclined from a Y-axis direction. In this case, the structures 3 and the oblique cylindrical lenses 28 forming the alignment marks are present in a direction parallel to the extending direction of the oblique cylindrical lenses 28 of the flat part 2 . That is, except the flat parts 2 required for the alignment marks, by making as the oblique cylindrical lenses 28 , as illustrated in FIG. 33A , an area 4 b that can be set in the display area may be expanded.
[0135] The oblique cylindrical lenses 28 has, as illustrated in FIG. 32 , an extending direction inclined with respect to sides forming an external form of the lenticular lens sheet 8 c . Herein, the inclined state means that the lenses are not parallel or perpendicular to the sides. In FIG. 32 , the extending direction of the cylindrical lens is inclined with respect to the four sides forming the external form, and the alignment marks 29 g and 29 i ( 29 h and 29 j ) are provided on the extending direction of the oblique cylindrical lenses 28 separated from each other, such that the alignment marks 29 g and 29 i ( 29 h and 29 j ) may be disposed at the corners of the lenticular lens sheet 8 c . FIG. 34 , illustrates a lenticular lens sheet using the oblique cylindrical lenses 28 to which the configuration of the first embodiment is applied. In this case, the alignment marks 29 n and 29 o among four alignment marks 29 m , 29 n , 29 o and 29 p are disposed at positions which are not the corners of the lenticular lens sheet, such that the area represented by 4 c becomes an area that can be set in the display area, which is significantly smaller than the area 4 b illustrated in FIG. 33A of the second embodiment.
[0136] The lenticular lens sheet of the second embodiment may be manufactured, for example, by transferring the shape of a mold 27 a as illustrated in FIGS. 35A and 35B to a resin. A method of manufacturing the mold 27 a will be described using FIGS. 35A and 35B . As illustrated in FIG. 35A , leaving a flat-part forming part 2 a , a cylindrical lens forming part 1 a is formed in the mold 27 a . In this case, by changing the tool bit from a descended state (cutting state) to an ascended state (non-cutting state) with respect to the extending direction of the lens, the flat-part forming part 2 a may be formed. This point is largely different from the case of FIG. 25A of the first embodiment.
[0137] Further, in the formation of the flat-part forming part 2 a , because the tool bit is gradually ascended (pulled out) as a processing considering a tool bit load, as illustrated in FIG. 35A , a pull-out trace 14 (slant-hatching portion in FIG. 35A ) occurs. The mold is also processed by beginning of the cutting of the cylindrical lens forming part 1 a while the tool bit is gradually descended, thereby a trace having a shape similar to the pull-out trace may be formed.
[0138] Next, in FIG. 35B , as similar to FIG. 25B , a structure forming part 3 a is formed by making the tool bit in the descended state from one cylindrical lens forming part 1 a to the other cylindrical lens forming part 1 a which face to each other with the flat-part forming part 2 a interposed therebetween by penetrating the flat-part forming part 2 a . Further, for clarity of the processed shape, slant-hatchings are added to the cut portions of the cylindrical lens forming part 1 a in FIG. 35B . In addition, the structure 3 may use the cylindrical lens extending in the Y direction, the hexahedron, the prism or the like. When the pull-out trace 14 of the tool bit and the alignment mark are separated from each other at some distance, the boundaries between the Y-direction cylindrical lens 1 and the flat part 2 , and between the structure 3 and the flat part 2 can be recognized by a simple image recognition device in a short time with high accuracy.
[0139] FIG. 33B illustrates another oblique cylindrical lens of the second embodiment. As illustrated in FIG. 33B , except the flat parts 2 required for the alignment marks 29 k and 29 l , it is possible to make both sides of the flat parts 2 in the extending direction thereof as the oblique cylindrical lenses 28 . In addition, similar to the case of the Y-direction cylindrical lenses 1 as illustrated in FIG. 30 , except the flat parts 2 required for the alignment marks, it is possible to make the both sides of the flat parts 2 in the extending direction thereof as the Y-direction cylindrical lenses 1 .
Third Embodiment
[0140] The third embodiment, which will be described below, may be applied to the first and second embodiments, but, in particular, the case of being applied to the first embodiment with a large effect will be described. In the third embodiment, the structure 3 will be described as an example of the X-direction cylindrical lens, but the hexahedron, the prism, or the like may also be applied thereto.
[0141] In FIG. 23B , the height of the structure 3 is defined by setting the flat part 2 (or the lower flat surface of the cylindrical lens) as a reference surface. Similarly, the height of the Y-direction cylindrical lens 1 is also defined by setting the flat part 2 (or the lower flat surface of the cylindrical lens) as the reference surface. In the first embodiment, as illustrated in FIG. 23B , the height of the structure 3 and the height of the Y-direction cylindrical lens 1 are substantially the same as each other, but in the third embodiment, the height of the structure 3 is configured to be shorter than the height of the Y-direction cylindrical lens 1 . Except this difference, the third embodiment uses the same structure as the first and second embodiments.
[0142] FIG. 36 is a front view illustrating a lenticular lens sheet 8 d of the third embodiment. FIG. 37 is a cross-sectional view taken on line D-D′ of FIG. 36 . The structure of the third embodiment is suitable in the case of performing the bonding process of the lenticular lens sheet with the display panel under a reduced pressure, while the protection film is bonded to the lens surface side of the lenticular lens sheet 8 d , which will be described in detail below. Further, the protection film serves to prevent damage to the lens, or adhering of foreign matter.
[0143] FIG. 38 is an enlarged front view illustrating the alignment mark of the third embodiment. In addition to the front view illustrating FIG. 36 , FIG. 38 illustrates a contact part 5 of the protection film with the lens. When the protection film is bonded to the lens surface of the lenticular lens sheet, an adhesive of the protection film is firmly adhered to high regions of the Y-direction cylindrical lens 1 . Meanwhile, by making the height of the structure 3 b to a level which does not allow the adhesive of the protection film to be firmly adhered thereto, the protection film and the structure 3 b are not in directly contact with each other. FIG. 39 is a cross-sectional view taken on line E-E′ of FIG. 38 , after a protection film 6 is bonded to the lenticular lens sheet 8 d . The structure 3 b is not firmly adhered to an adhesive 10 of the protection film 6 , such that a leakage path 7 may be formed on the structure 3 b . This leakage path 7 is favorably operated in the bonding process of the lenticular lens sheet with the display panel under a reduced pressure.
[0144] The structure and the Y-direction cylindrical lens will be described by comparison with the case that the heights thereof are substantially the same as each other. FIG. 40 is an enlarged front view illustrating the alignment mark, when the height of structure 3 and the height of the Y-direction cylindrical lens 1 are substantially the same as each other. When the protection film 6 is bonded to the display surface of the lenticular lens sheet, the structure 3 is also firmly adhered to the adhesive 10 of the protection film 6 . FIG. 41 is a cross-sectional view taken on line F-F′ of FIG. 40 , after the protection film 6 is bonded to the lenticular lens sheet. In this state, when the lenticular lens sheet is made to be in a reduced pressure environment, a relative pressure of air in a space closed by the Y-direction cylindrical lens 1 , the structures 3 , the protection film 6 and the flat part 2 becomes higher than outdoor air. As a result, the protection film 6 of this region is swollen, it is difficult to see the alignment mark due to an influence by the influx of a gas, or the protection film 6 is peeled off. Meanwhile, in the third embodiment, there is no closed space since the leakage path 7 is provided therein as illustrated in FIG. 39 , and thereby problems such as swelling or peeling of the protection film 6 even under a reduced pressure may not occur.
[0145] Further, when the protection film is bonded to the lens surface of the lenticular lens sheet of the second embodiment, since only one alignment mark is provided on the extension of the same flat part, the closed space as illustrated in FIG. 40 may not be formed therein. However, by applying the third embodiment to the second embodiment, the leakage path is increased, such that it is possible to more efficiently pull out the air between the lens surface and the protection film under a reduced pressure environment, and more easily execute the bonding process of the lenticular lens sheet with the display panel under a reduced pressure.
Fourth Embodiment
[0146] In the fourth embodiment, the lenticular lens sheets according to the first, second and third embodiments are combined with the display panel such as a liquid crystal or organic electroluminescence (EL) or plasma display panel (PDP), to make a stereoscopic display.
[0147] As illustrated in FIGS. 42 and 43 , the lenticular lens sheets 8 and 8 a are bonded to the display panel 9 through the adhesive 10 a . FIG. 42 is a cross-sectional view illustrating the stereoscopic display apparatus in which the integral lenticular lens sheet 8 as illustrated in FIG. 24 is bonded to the display panel 9 . FIG. 43 is a cross-sectional view illustrating the stereoscopic display apparatus in which the lenticular lens sheet 8 a using the glass substrate 12 is bonded to the display panel 9 . The adhesive 10 a may be a liquid adhesive, or film-shaped adhesive. In this case, the cylindrical lenses of the lenticular lens sheets 8 and 8 a are installed astride at least two pixels (two columns) of a right-eye pixel and a left-eye pixel. Thus, a stereoscopic display apparatus 11 capable of displaying a stereoscopic image is completed. That is, the stereoscopic display apparatus 11 of the fourth embodiment is provided with the lenticular lens sheet of the first embodiment. In addition, the stereoscopic display apparatus including the lenticular lens sheets of the second and third embodiments may be similarly configured. Further, as described in the third embodiment, the protection film may be attached to the upper surfaces of these lenticular lens sheets.
[0148] In the stereoscopic display apparatus of FIGS. 42 and 43 , a distance between the lenticular lens sheets 8 and 8 a and the pixels of the display panel 9 (referred to as a lens-to-pixel distance) is important to achieve the stereoscopic display. A lens pitch, a pixel pitch, a distance that can allow the easiest viewing of the stereoscopic display (optimum 3D viewing distance), the number of viewpoints, and the like determine the lens-to-pixel distance. The number of viewpoints is the number of different viewpoint images projected in a space for the stereoscopic display. For example, when one lens is installed astride the two pixels of the right-eye pixel and the left-eye pixel, an image of each one viewpoint for the right-eye and left-eye, that is, two viewpoints are projected. Also, for example, when one lens is installed astride the four pixels, an image of four viewpoints is projected, and the number of viewpoints may be changed depending on a relation between the pixel and the lens. In the case of the same optimum 3D viewing distance and the same number of viewpoints, since there is a proportional relationship between the pixel pitch and the lens-to-pixel distance, when the pixel pitch is reduced, it is necessary to reduce the lens-to-pixel distance. In recent years, the display panel has increased in definition, and the lens-to-pixel distance has tended to decrease.
[0149] FIGS. 44A to 44C are perspective views illustrating an electronic equipment in which the stereoscopic display apparatus 11 of the fourth embodiment may be applied, wherein FIG. 44A illustrates a personal computer 22 as a first example, FIG. 44B illustrates a television 23 as a second example, and FIG. 44C illustrates a Pachinko machine 24 as a third example.
[0150] The stereoscopic display apparatus 11 of the fourth embodiment is not limited thereto, and in addition, may be applied to various electronic equipment such as a mobile phone, a smart phone, a personal digital assistant, a game console, a digital camera, a digital video camera, a car navigation system, a system monitor, a vehicle-mounted monitor and the like. When using the lenticular lens sheet according to the first, second or third embodiment, since it is easy to align the lenticular lens sheet with the display apparatus with high accuracy, productivity is improved. In addition, as compared to the prior art, it is possible to supply the lenticular lens sheet at a low cost. By the above-described fourth embodiment, it is possible to provide the electronic equipment which has excellent visual characteristics and display quality, and is capable of displaying different images from a plurality of viewpoints, at a low cost.
[0151] Further, it should be noted that the present invention is not intended to be limited to the description of the above-described respective embodiments, and the configuration thereof may be appropriately modified, without departing from the spirit of the present invention.
[0152] The present invention can be used in the lenticular lens sheet, and the display apparatus and the electronic equipment including the lenticular lens sheet.
[0153] As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims.
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Provided are a lenticular lens sheet capable of simultaneously achieving an improvement in visibility due to improving bonding accuracy, and low cost due to shape stabilization during processing the lens, a display apparatus and an electronic equipment including the same. The lenticular lens sheet includes a plurality of cylindrical lenses which extend in a direction parallel to each other; and an alignment mark which has two cylindrical lenses among the plurality of cylindrical lenses, a flat part disposed between the two cylindrical lenses, and a structure which is disposed on the flat part and extends between the two cylindrical lenses.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to the commonly owned U.S. patent application Ser. No. 10/910,607, filed Aug. 4, 2004, which issued as U.S. Pat. No. 7,496,563; U.S. patent application Ser. No. 10/910,606, filed Aug. 4, 2004, abandoned; U.S. patent application Ser. No. 10/910,568, filed, Aug. 4, 2004, which issued as U.S. Pat. No. 7,421,421; U.S. patent application Ser. No. 10/910,641, filed Aug. 4, 2004, abandoned; U.S. patent application Ser. No. 10/910,617, filed Aug. 4, 2004, which issued as U.S. Pat. No. 7,385,260; U.S. patent application Ser. No. 10/910,577, filed Aug. 4, 2004, which issued as U.S. Pat. No. 7,634,461; co-pending U.S. patent application Ser. No. 10/910,603, filed Aug. 4, 2004; and U.S. patent application Ser. No. 10/910,640, filed Aug. 4, 2004, which issued as U.S. Pat. No. 7,493,303, each filed herewith and incorporated by reference in its entirety.
FIELD OF THE INVENTION
The invention relates to an application for searching a document that a user has previously viewed on user terminal device.
BACKGROUND OF THE INVENTION
Many programs enable a user to search for documents located on the computer device. For example, a user may be able to search for a document by entering search terms believed to reflect the document's title or by entering search terms believed to be included in the document text. However, conventional document management tools are limited in the amount of search criteria that a user may use to locate a particular desired document.
Often, users only remember, or have access to, small bits of information related to the document for which they are searching, such as, for example, the day and/or approximate time the document was accessed, a broad overview of what the document was about, and/or other details. Users are generally not good at creating search criteria, particularly based on such limited information, and would be better at modifying a search if they were give clues to form a more effective search.
It is an aspect of the invention to assist a user with searching specifically for documents the user has previously accessed by providing criteria that might enable the user to more easily locate a particular desired document.
It is another aspect of the invention to provide a graphical user interface with various features and functions to facilitate the user with locating the document once the search has been performed.
SUMMARY OF THE INVENTION
These and other objects are addressed through various embodiments of the invention. According to one aspect of the invention, a system and method are provided for quickly and efficiently searching for and selectively retrieving one or more documents that a user has previously accessed. The previously accessed documents may or may not be located at the user's local workstation. As used herein, the term documents may refer to files such as, for example, Microsoft Word or Excel documents, email messages, web pages, media files, folders, and/or other files.
The system may include a desktop integration module, an index module, a graphical user interface module, and/or other modules. The desktop integration module may monitor documents with which the user interacts for predetermined events and obtain content data and metadata from the monitored documents. The index module may index the content data and metadata received from the desktop integration module. The graphical user interface module may then permit a user to utilize the index module by allowing a user to search for documents.
The desktop integration module may monitor documents that the user views, edits, creates, or otherwise accesses for predetermined events. For example, the desktop integration module may track each time a user opens a document and each time the user closes the same document, enabling the duration of document interaction to be determined. The desktop integration module may obtain content data, such as keywords, title of the document, author of the document, and/or other control data and metadata determined from the predetermined events for the monitored documents, and transfer the content data and metadata to the index module.
The index module may index parameters that enable the user to search and filter the monitored documents. For each document monitored by the desktop integration module, the index may include parameters such as, for example, the date created, the date opened, the date closed, the date modified, the amount of time spent on a document, the date printed, the date sent, the number of times of document was accessed, and/or other parameters. The index module may also store keywords from the document, the title of the document, and/or the author of the document. These parameters in the index module may be determined from the content data and metadata collected by the desktop integration module. A filter may be provided, enabling user to specify documents that are not to be indexed, such as a default home page or personal email.
The graphical user interface module may enable a user to perform searches of the index created by the index module and therefore locate a document which has been previously accessed by the user. The results reflect documents considered relevant in content based on the search terms and other parameters entered by the user such as, for example, dates and selected applications. The user may browse the search results and/or sort the result set by various criteria for ease of viewing.
According to one aspect of the invention, desktop integration module may include one or more subsystems, such as, for example, application plug-ins, a communications module, a user interaction module, a document filter module, and/or other modules. The desktop integration module may track each instance in which a user enters a URL to access a web page. In some embodiments, the desktop integration module may track web pages that a user visits by accessing a link on a page for which a URL was entered. In other embodiments, the desktop integration module may track an instance where the user opens a Word document or reads an email.
A document filter module may be provided to enable a user to specify documents that should not be monitored or indexed. For example, documents that a user commonly accesses or documents that contain private information such as, for example, online bank account statements or webpages with the “https” protocol may be filtered and not indexed.
Application plugins may extract information from documents such as, for example, document type, content, and/or author. Communications module may be used to queue documents being retrieved from application plugins to the index module. Communications module may also convert documents from their native format, such as, for example, .DOC or .XLS, to a common XML format. User interaction module may interact with application plugins to track the amount of time a user spends interacting with a document.
According to another aspect of the invention, the graphical user interface module may present a graphical user interface having multiple graphical visualizations of a search results set. A calendar may be displayed indicating when a user has accessed a document in the search results set. A document usage histogram may be displayed illustrating all documents that the user has accessed compared to those documents matching the search query.
According to another aspect of the invention, a histogram displayed on a graphical user interface may allow a user to see the context of the result set against their own document usage. Vertical lines may be presented indicating documents that match the search query. The vertical lines may be of varying heights, indicating the relevance of the document to the search query.
According to another aspect of the invention, multiple related histograms may be provided. The histograms may represent the relevance of the search results, as well as the number of documents matching the search criteria for a given day. The histogram may have one axis displaying, for example, dates and times, and another axis displaying, for example, the amount of time spent on a particular document.
According to another aspect of the invention, better search results for specific users may be returned by enhancing the result set rankings according to a specific user's interest in the document. User metrics may be collected during a user's interaction with other documents to enhance keyword relevance rankings. User metrics may include the time spent on a document, frequency with which the document was viewed, whether the document is printed, and/or other metrics. The amount of time a user has spent on a document may be measured if one or more criteria such as, for example, whether the document is in focus and/or whether some type of input has been received relative to the document within a particular time interval, are met.
According to another aspect of the invention, historical data related to a user's interaction with a document may be provided with a search results set. This may allow a user to more readily distinguish between documents in the results set.
A user may view metrics obtained by the desktop integration module by performing a triggering action, for example, by right-clicking on a document in the results set or other triggering action. Performing the triggering action may cause the calendar and histogram views to change, reflecting the additional information.
According to one aspect of the invention, the search system may be embedded into a user's calendar and/or email application. The user may then generate search queries by performing a triggering action on a selected calendar or email entry. The search query may include, for example, the title of a meeting, meeting attendees, dates, keywords in the body of the calendar or email entry, and/or other query options.
According to another aspect of the invention, a system and method may be provided, enabling users to search a local workstation from an enterprise portal. This may enable the user to search their local workstation as well as other document management systems simultaneously. An index control program and a web responder may be downloaded to a user's workstation. Documents may then be indexed at the user workstation and inbound query requests by an enterprise portal server may be accepted.
A user may perform a search of their workstation through an enterprise portal. The search query may be processed at the local workstation and results may be returned in a format compatible with the enterprise server.
Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings. The drawings are designed for purposes of illustration only and the invention is not limited to the particulars shown therein. Various alternatives and modifications within the scope of the invention will be apparent from the description contained herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating a system for searching for previously accessed documents, according to an embodiment of the invention.
FIG. 2 illustrates a graphical user interface, according to an embodiment of the invention.
FIG. 3 illustrates a web portal having an embedded search field, according to an embodiment of the invention.
FIG. 4 is a flowchart illustrating an operation of a desktop integration module, according to an embodiment of the invention.
FIG. 5 illustrates a graphical user interface, according to one embodiment of the invention.
FIG. 6 illustrates a chronology histogram, according to an embodiment of the invention.
FIG. 7 illustrates another chronology histogram, according to an embodiment of the invention.
FIG. 8 illustrates a graphical user interface, according to an embodiment of the invention.
FIG. 9 illustrates a graphical user interface, according to an embodiment of the invention.
FIG. 10 illustrates a results set listing, according to an embodiment of the invention.
FIG. 11 illustrates a calendar view from an email program, according to an embodiment of the invention.
FIG. 12 is a block diagram of a system for searching from a remote portal, according to an embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to one embodiment of the invention, a system 100 may be provided enabling a user to search for and/or selectively retrieve documents that the user has previously accessed. FIG. 1 is a block diagram of system 100 , according to an embodiment of the invention. A search agent 102 may be provided. Search agent 102 may include one or more modules such as, for example, a desktop integration module 104 , an index module 106 , a graphical user interface module 108 , and/or other modules. Search agent 102 may be located at a user terminal 110 . In some embodiments, certain modules such as, for example, index module 104 may be implemented at user terminal 110 , while other modules may be implemented at user terminal 110 or remotely. Other variations may be used, as would be apparent.
User terminal 110 may include any one or more of for example, a desktop computer, a laptop or other portable computer, a hand-held computer device such as a Blackberry, a Personal Digital Assistant (PDA), and/or any other terminal device. User terminal device 110 may be connected to an enterprise portal server 112 over a network 114 via a communications link 116 .
Server 112 may enable a user to remotely search for documents the user has accessed, even if these documents are stored at the user's terminal device. Server 112 may be or include, for example, a workstation running Microsoft Windows™ NT™, Unix, Linux, Novell Netware™, and/or other operating systems. Network 114 may include any one or more networks, such as, for example, the Internet, an intranet, a Local Area Network (LAN), and/or other networks. Communications link 116 may include any one or more communications links such as, for example, a copper telephone line, a Digital Subscriber Line (DSL) connection, an Ethernet connection, an Integrated Services Digital Network (ISDN) line, a wireless connection, or other communications link.
Desktop integration module 104 may be provided to monitor documents accessed by a user for predetermined events. Desktop integration module 104 may monitor any document that the user views, edits, creates, prints, downloads, or otherwise accesses. These predetermined events may be or include, for example, opening a document, closing a document, printing a document, emailing a document, and/or other predetermined events.
Index module 106 may receive data from desktop integration module 104 and put the data into a format that may be searched by a user using a graphical user interface. Index module 106 may enable a user to filter search results by, for example, a date or date range, a document type, and/or other parameters. A user may specify certain documents that should not be indexed, such as, for example, a default homepage or a search index. Graphical user interface module 108 may provide a graphical user interface (GUI) that enables a user to search for a previously accessed document.
A user may initiate a query from a search portlet located on the user's portal page by using a traditional keyword search terms. The portal software may then direct the query to index module 106 and search results may be presented to the user in a new graphical user interface. A graphical user interface for displaying search results and modifying a search is described in detail hereinafter.
FIG. 2 illustrates an example of a portal page 200 having a search portlet 202 embedded therein. If a user enters a keyword search into search portlet 202 and does not have the system software for searching the local index stores on their workstation, the software may automatically be downloaded from server 112 . The user may be presented with a dialog box where the user may be asked if they would like to install the system. Once the user has consented to install the components, the index and a control program are downloaded and installed. Once installed, the program may begin to create an index of documents the user has accessed by searching well known browser caches for web documents and/or intercepting calls to known productivity applications.
A desktop integration module may monitor predetermined events by retrieving content data and metadata from the applications used to access the documents. Metadata may refer to data describing an action taken by the user such as, for example, choosing a “document open” or a “document close” action. Metadata may also indicate the date and/or time a document was accessed. Content data may include data such as, for example, words found in the document, keywords stored with the document, a name of the document, an author of the document, and/or other content data. In some embodiments, keywords may be specified by the user when creating or modifying a document. In some embodiments, keywords may be determined by desktop integration module 104 based on the frequency of occurrence of certain words in the document.
According to one embodiment of the invention, desktop integration module may include one or more subsystems. FIG. 3 illustrates desktop integration module 300 , according to an embodiment of the invention. Desktop integration module 300 may include one or more modules such as, for example, an applications plugin module 302 , a communications module 304 , a user interaction module 306 , a document filter module 308 , and/or other modules.
Application plugin module 302 may include one or more stand alone modules which may be instantiated when an application matching a specified type is started by the user or an operating system at the user's terminal. Application plugin module 302 may extract information from documents such as, for example, the document type, content as text, author, size, creation date, and/or other document information. Application module 302 may also collect information related to a user's access of or interaction with a document, such as, for example, whether a user forwards an email or other document, edits a document, prints a document, and/or other user access.
Application plugin module 302 may be connected to communications module 304 through a standard plugin interface. Communications module 304 may submit documents being retrieved from application plugin module 302 to index module 106 , enabling the documents to later be searched. Communications module 304 may convert documents into a format that can be readily indexed, such as, for example, from a binary .DOC format to a XML format.
User interaction module 306 may monitor an amount of time a document is accessed by the user. In some embodiments of the invention, user interaction module 306 may be integrated with the operating system used at the user's terminal to track the duration of a user's access of a document. For example, in a Microsoft Windows operating environment, Windows application programming interfaces, which may register file open and close operation, may be used to track the duration of a user's access of a document.
In some embodiments of the invention, some documents need not be tracked and indexed by the system. Document filters module 308 may be used to filter out documents that should not be tracked by the system. A user may define filters based on a number of factors such as, for example, document type, uniform resource identifiers (URIs), and/or other factors. For example, documents in the Microsoft Money application format may have personal financial information, so a user may wish to define a filter for excluding these documents from the index. Documents having URIs known to contain personal information such as, for example, “c:Document Settings\User\Personal”, or documents having URIs beginning with “https:\\” may be omitted. A user may also define filters for documents that are commonly accessed, such as a default browser homepage, or a search engine such as Google. Plugin specific filters may also be defined for omitting documents, such as emails from certain addresses, from being indexed.
FIG. 4 illustrates an example of the operation of desktop integration module 300 . At an operation 402 , an application, such as, for example, Internet Explorer, may be started by a user. The user may click on the Internet Explorer icon to start up the browser. At an operation 404 , an application plugin specific for Internet Explorer may start up. The application plugin may search for a communications module, or start a new singleton process, at an operation 406 . At an operation 408 , the browser may open up to a default homepage. The application plugin would then perform a filter check on the homepage URI to determine if the homepage is one that should not be indexed, as illustrated at an operation 410 . As illustrated at an operation 412 , if a filter has been set up for the current URI, no information is gathered, and no index entry is created. If no filter has been set up for the URI, an application plugin session may be created to track user activity, as illustrated at an operation 414 . At an operation 416 , user activity information may be collected and submitted to an index module.
According to one embodiment of the invention, graphical user interface module 108 may provide a graphical user interface for displaying search results and enabling a user to enter additional search criteria. FIG. 5 illustrates a graphical user interface 500 , according to one embodiment of the invention. Following an initial keyword search execution via portlet 202 , GUI 500 may be presented having results set 502 . Results displayed in results set 502 may be sorted in various ways such as, for example, by relevance, document type, alphabetically, chronologically, and/or other sorting methods. Sorting menu 504 may be provided, enabling a user to select a desired sorting method.
A user may choose to view only documents of a certain type by selecting one or more document type filters 506 . Additional keywords may be entered or a new search may be executed by entering search terms into query box 508 . Selecting recall button 510 may enable a search to be performed of all documents the user has previously accessed matching the search criteria.
In addition to standard search results displayed in search results box 502 , various graphical visualizations may be provided. A calendar 512 may be provided. Calendar 512 may include indicia 514 indicating days on which documents from the search result set have been accessed. Indicia 514 may indicate the first time a user has accessed a document, or in other embodiments may indicate each access by the user. As illustrated in FIG. 5 , indicia 514 may include highlighting a particular calendar day or days. Other visual indicators may be used, as would be apparent. A user may restrict results displayed in search results box 502 by selecting one or more dates from calendar 512 . Results box 502 entries may then be limited to documents which have been accessed on the selected dates.
A histogram 516 may be provided for controlling the result set in a similar manner to calendar 512 . A user may select either end of bounding box 518 to dynamically revise the result set, showing only those results within the selected date range. Histogram 516 may illustrate documents matching the search query in addition to all documents accessed by the user, allowing the user to see which documents were used within which sequence. For example, dark colored vertical lines 520 a may indicate documents that match the search criteria, while light colored vertical lines 520 b may indicate all other documents the user has accessed. Other visual indications may be used, as would be apparent.
According to an embodiment of the invention, a user may retrieve a chronological display of document usage. FIG. 6 illustrates a chronology histogram 600 , according to this embodiment of the invention. Chronology histogram 600 may be provided wherein both results set documents and other used documents are shown as vertical bars on a horizontal timeline. Horizontal timeline 602 provides a date range for which chronology information may be obtained. This date range may be extended by selecting and dragging the ends of bounding box 604 outward. The date range may also be contracted by dragging the ends of bounding box 604 inward.
In addition to the timeline on the horizontal axis, the height of each bar may provide additional information to the user about a document. The height of vertical lines may indicate the relevance of each document to the search query. In an alternative embodiment, the height of the vertical lines may indicate a specific usage pattern such as, for example, the amount of time spent working in a specific document. A user's usage activity may be recorded by Desktop Integration Module (shown in FIG. 1 ) and this information may be normalized to display a usage summary on chronology histogram 600 .
Selecting a vertical line may open the selected document directly. In other embodiments, selecting a vertical line may cause a popup window 606 to be displayed. Pop-up window 606 may display a result set summary for the selected document. Summary information displayed in popup window 606 may include, for example, the document name, document location, document type, a summary of the document content, and/or other document related information.
According to one aspect of the invention, multiple variables may be characterized on the vertical axis of a chronology histogram. FIG. 7 illustrates a chronology histogram 700 , according to this embodiment of the invention. Displaying multiple variables may enable a user to quickly and efficiently locate a desire document. As illustrated, chronology histogram 700 displays both relevance of search results documents to the entered keywords as well as the amount of time spent accessing or interacting with the document. Other document characteristics may be displayed such as, for example, the number of hits.
Vertical axis 701 may provide multiple variables such as, for example, a relevance variable 702 and a duration variable 703 . White boxes 704 may be provided to illustrate the time a user has spent on a document. This time may be illustrated for all documents a user has accessed, whether or not a particular document matches the search criteria. Shaded boxes 706 may indicate the relevance of one or more documents matching the criteria. Horizontal axis 708 may indicate one or more dates a document was accessed. Horizontal axis 708 may also indicate, chronologically, the order in which a document was accessed. In some embodiments of the invention, horizontal axis 708 may provide a time display, indicating the time interval in which a document was accessed.
According to one aspect of the invention, relevance calculations for search results are enhanced for a specific user by collecting user metrics during the user's interaction with the document. In addition to ranking documents based on the frequency and location of keyword hits and the proximity of query keyword hits to each other, the invention may collect metadata using desktop integration module 104 (illustrated in FIG. 1 ). Collected metadata may include, for example, the amount of time spent on a document, how often a document has been viewed, or otherwise accessed, whether or not the document was printed or emailed, and/or other document related actions.
Certain criteria may be required in order to determine the amount of time a user has spent interacting with a document. For example, it may be a requirement that the user has the document open and in focus. In focus may refer to having the selected document as the active window when multiple documents and/or applications are open. A user may be required to perform some type of input/output operation within a predetermined time interval in order for time calculation to continue. For example, the input/output operation may be a keystroke or mouse movement.
Once the criteria have been satisfied, the collected metadata may be entered into the index using index module 106 (illustrated in FIG. 1 ). Opening a document multiple times may cause metadata to be obtained for both frequency and duration of use. For example, a document that has been opened three times may show a frequency of three, and the total amount of time spent among the three accesses may be combined to calculate the amount of time the user has spent on the document.
According to another aspect of the invention, metrics regarding a user's interaction with one or more documents may be presented to the user on a graphical user interface. Presenting user metrics to the user may enable the user to more readily distinguish between documents in the result set and simplify the process of finding the desired document.
In some embodiments of the invention, a user may trigger the user interface to present user metrics by performing an action such as, for example, right-clicking on the document in the result set. A pop-up window 802 may be provided, as illustrated in FIG. 8 . Pop-up window 802 may display, for example, document name, document location, the number of times the document has been opened by the user, the total amount of time the user has spent on the document, and/or other user metrics.
In some embodiments of the invention, user metrics may be displayed when a user hovers over a document in the result set. Hovering over a document may cause a change in the calendar and/or histogram graphical representations. For example, as illustrated in FIG. 9 , calendar 902 may highlight days on which the selected document has been accessed. Histogram 904 may provide additional user metrics. For example, the x-axis of histogram 904 may display the dates in which the user accessed the selected document, while the y-axis illustrates the amount of time the user spent on the document. Small icons, such as icons 906 , may be presented on histogram 904 , indicating the amount of time the user spent on the document. Other icons may also be presented, for example, a printer icon, book icon, and/or envelope icon may be presented to indicate that the user has printed, read, and/or emailed the document, respectively. Other icons may be presented indicating editing of a document, forwarding, replying, and/or other document related actions, as would be apparent.
While certain actions have been described above, other actions may be used to present user metrics to the user. For example, a user may single click on a document to change the views of the histogram and calendar, or the user may double click on a document to open a new window providing user statistics.
According to an embodiment of the invention, user metrics may be provided directly in the results set without requiring additional actions to be performed. FIG. 10 illustrates a result set 1000 which provides user metrics. User metrics illustrated in result set 1000 may include, for example, the total viewing time for each document, the amount of time the document was viewed, and the date the document was last accessed. Other user metrics may be provided, as would be apparent.
According to another aspect of the invention, the system may be integrated into a user's email and calendar application. A user may quickly obtain documents relevant to a particular email message or calendar entry. A user interface for searching based on a user's email and calendar entries may be integrated with the email applications in some embodiments, or may be a standalone application.
FIG. 11 illustrates an example of a calendar view 1100 associated with an email program such as, for example, Lotus Notes. As illustrated, several meetings 1110 are listed on calendar 1100 . A user wishing to view documents related to a scheduled meeting may do so by selecting the meeting and choosing an option to search for related documents. Options may be provided by various ways, such as, for example, “right-clicking” on a meeting to bring up a pop-up menu, choosing an option from Actions menu 1112 , or other methods as would be apparent. Search criteria may also be created from an email message. Search criteria may include, for example, the title of the meeting, subject of the email message, keywords from the body of an email message, names of meeting invitees, and/or other criteria.
Desktop integration module 102 may obtain content and metadata from calendar 1100 regarding the selected meeting. Indexing module 104 may use the retrieved metadata and content data and compare it to the indexed data for all stored documents. Documents having matching content data and/or metadata may be returned as being related to the selected meeting. In other embodiments, authors of documents may associate the document with certain meetings. In some embodiments of the invention, only documents accessed on the day of the meeting are retrieved while in other embodiments, all accessed documents related to the meeting are returned.
Once the user has been presented with search results, the user may modify the search to more quickly find desired documents. For example, the user may input additional keywords, use document type filters to return only documents of certain types, restrict the search to one or more dates, and/or other search modifications.
According to another aspect of the invention, a system may be provided, enabling a user to search a local workstation from a remote portal location. As used herein, local workstation may refer to the workstation that is assigned to a particular user and from which the user typically works. A user may have access to documents stored on their local device and may be able to integrate these documents into a portal integration environment.
As described above, in some embodiments of the invention, an index and control program may be downloaded to a user's workstation the first time a query is made using the portlet. In addition to the index and control programs, a web responder may also be installed. FIG. 12 illustrates a block diagram 1200 of the system including web responder 1202 . In some embodiments of the invention, web responder 1202 listens for inbound queries from Enterprise Portal Server 1204 over network 1206 . Once web responder 1202 has been installed, queries from Enterprise Portal Server 1204 may be accepted at user terminal 1210 .
A user may perform a search from Enterprise Portal Server 1204 in a manner similar to performing a local search. The user may enter a search query into a portal page, such as the portal illustrated in FIG. 2 . The query may then be sent to the local workstation where the web responder has been installed. An index at user terminal 1210 may then process the query and return the results in a format supported by Enterprise Portal Server 1204 , such as, for example, the XML format. Results may then be formatted and presented to the user.
According to one embodiment of the invention, searching a local workstation index may be performed as a part of a search from another application. For example, a single search may be used to search a user's workstation, email documents, and/or a corporate document management system using a search engine integrated with the document management system. Search results may be combined into one display. In an alternative embodiment, only the user's own documents are searched using the index at the user's workstation.
While particular embodiments of the invention have been described, it is to be understood that modifications will be apparent to those skilled in the art without departing from the spirit of the invention. The scope of the invention is not limited to the specific embodiments described herein. Other embodiments, uses and advantages of the invention will be apparent to those skilled in art from consideration of the specification and practice of the invention disclosed herein. The specification should be considered exemplary only, and the scope of the invention is accordingly intended to be limited by the following claims.
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A method is provided for enabling a user to search for documents that the user has previously viewed on its local machine. The method may rely upon three main system components: the desktop integration module, the index module, and the graphical user interface module. The desktop integration module is an application which monitors documents with which the user interacts for predetermined events, and obtains content data and metadata from the monitored documents. The index module indexes the content data and metadata received from the desktop integration module. The graphical user interface module then permits a user to utilize the desktop integration module and index module by allowing a user to search for a document.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 09/598,795, filed Jun. 21, 2000, the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a corner guard for protecting the corners of walls in institutional facilities, and relates in particular to a multi-colored, co-extruded corner guard.
[0004] 2. Discussion of the Related Art
[0005] In institutional facilities such as hospitals, elderly care centers, and other public buildings, the corner of building walls are exposed to damage from impact resulting from forceful contact with various kinds of wheeled vehicles, such as stretchers, wheelchairs, dining carts and the like. For this reason, the corners of the building wall are commonly provided with a corner guard that will protect the wall surfaces from damage resulting from the impact.
[0006] Conventional corner guards are normally comprised of an elongated plastic member that is angled to fit over the corner formed by the intersection of two walls. The corner guard may be fastened to the wall with an adhesive, such as double-sided adhesive tape. Alternatively, the corner guard may be comprised of an assembly that includes a base plate which overlays the wall surfaces at the corner, and further includes a cover member that is attached over the base plate. For both the adhesive and mounted types of corner guards, the outer plastic corner guard member from damage due to impacts by wheeled carts and that like that occasionally hit the walls and corners of hallways.
[0007] Examples of conventional corner guard assemblies include the devices disclosed in U.S. Pat. No. 3,717,968 issued to Robert W. Olsen, et al, U.S. Pat. No. 4,430,883 issued to Claude P. Balzer et al, and U.S. Pat. No. 5,363,617 issued to Donald W. Miller.
[0008] Conventional corner guards and corner guard assemblies are typically manufactured by extruding a plastic resin into long pieces of a desired shape and color. Thus, conventional corner guards are comprised of a single grade and color of plastic material. Such single color corner guards are commonly considered bland and aesthetically undesirable. There is of course a continual demand to improve upon the aesthetic features and interior design of living and work spaces. Additionally, in hospitals and other large institutional facilities, the hallways are often color-coded to designate particular departments and locations within the building. The color-coding of hallways also provides a means of directional marking to assist users and visitors traversing through the building. Single-color corner guards, however, conform to the color scheme of one hallway or the other, but normally not both.
[0009] Accordingly, a corner guard that has improved aesthetic qualities and that will enhance the color-coding schemes of large institutional facilities is desired.
SUMMARY OF THE INVENTION
[0010] An improved corner guard designed especially for use in institutional type facilities is presented. The corner guard of the present invention includes an elongated vinyl corner member angled to fit over the corner formed by the intersection of two wall surfaces, the corner member being comprised of two different colors of vinyl plastic material that have been co-extruded to form a single, integrated product. The corner guard of the present invention provides an aesthetically improved corner guard that may be used in a much wider range of interior designs. Additionally, the improved corner guard disclosed herein may be used a part of a system of color-coding the hallways of a large hospital or other institutional facility. The corner guard of the present invention may be constructed as either a tape-on corner guard that is mounted by an adhesive directly to the wall surfaces, or constructed as an assembly comprised of a base plate and cover guard.
[0011] The present invention protects the corner of intersecting hallways from impacts and collisions, provides a visual enhancement to the interior design of buildings, and provides a multi-colored component for use in the color-coding of hallways and passageways in buildings. Other objects and advantages of the invention will become apparent from the following detailed description, which, together with the accompanying drawings, sets forth by way of illustration and example certain preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The drawings, which constitute a part of this specification and include an exemplary embodiment of the present invention, include the following.
[0013] [0013]FIG. 1 is a perspective view illustrating the corner guard of the present invention assembled to the corner of a building wall.
[0014] [0014]FIG. 2 is an exploded view illustrating the corner guard of the present invention and the manner in which it is assembled to the corner of a building wall.
[0015] [0015]FIG. 3 is a cross section view of the corner guard of the present invention, shown assembled to the corner of a building wall.
[0016] [0016]FIG. 4 is an end view of the corner guard of the present invention.
[0017] [0017]FIG. 5 is a perspective view illustrating the inner surfaces of the corner guard that are applied the surface of the building walls.
[0018] [0018]FIG. 6 is a perspective view illustrating a second embodiment of the corner guard of the present invention and the method that it is assembled to the corner of a building wall.
[0019] [0019]FIG. 7 is an end view of a third embodiment of the corner guard of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Referring to FIGS. 1, 2 and 3 , a corner 10 of a building wall is defined by the intersection of two wall surfaces. The corner may be formed by assembling at right angles a first panel 11 and a second panel 12 of drywall, sheetrock, or the like. The walls define hallways and corridors for directing pedestrians and wheeled vehicles such as carts, mobile tables, wheelchairs and the like through the building. Thus the corner is subject to impact from such vehicles occasionally striking the corner of the wall with various degrees of force. Accordingly, a corner guard 20 is applied to the corner of the building wall.
[0021] The present invention of a multi-colored co-extruded corner guard 20 is comprised of a corner guard member 21 and a means for fastening the corner guard member 21 to the corner 10 of the building wall. The corner guard member 21 is an elongated member that is comprised of a first flat planar portion 25 and a second flat planar portion 26 . The two flat planar portions, which intersect each other at an apex 22 , extend the entire length of the corner guard member 21 . The first flat planar portion 25 is applied over the first wall surface 11 , and the second flat planar portion 26 is applied over the second wall surface 12 . The apex 22 abuts directly against the sharp corner 10 of the intersecting wall surfaces 11 and 12 . The apex 22 preferably has small radius to provide a smoother finish to the corner of the wall.
[0022] The first flat planar portion 25 intersects the second flat planar portion 26 preferably at an angle that corresponds to the angle of intersection of the first and second wall surfaces 11 and 12 , which normally should be about 90°. The corner guard member 21 is made preferably of a thermoplastic material, preferably an extruded polyvinyl chloride plastic material (PVC). In the construction of building walls, the two intersecting wall surfaces 11 and 12 that form the corner 10 are occasional assembled together in a manner that does not form a precise right angle. In that event, the thermoplastic corner guard member 21 may be flexed a slight amount in order to properly fit over the corner of the building wall to which the corner guard 20 is being applied.
[0023] As mentioned, the corner guard member 21 is fabricated preferably from a rigid PVC material. Rigid polyvinyl chlorides normally have little or no plasticizer added to the material. One particular grade of material that is known to work satisfactorily is Synergistics Polycor D1015 Natural. The material comes in pellets that are melted and extruded through a die to form the retainer member. The properties of this material include a Shore D hardness scale according to ASTM Standard D2240 of about 80, and a tensile strength according to ASTM Standard D638 of about 6800 psi. This particular material is also available in a variety of colors. Other comparable materials having similar characteristics may be available in the market.
[0024] The corner guard member 21 is further comprised of at least two colors of thermoplastic material that are simultaneously co-extruded and bonded together in order to form a single integrated product. The corner guard member 21 of the present invention may be fabricated by thermo-bonding one layer of one color thermoplastic material to a second layer of a second color of thermoplastic material in such a manner that both layers are exposed to the outer surface 27 of the corner guard and thus visible from the hallways. Additionally, the layers are bonded to each other so that the final product has a constant thickness across its entire width.
[0025] Specifically, the first flat planar portion 25 includes a first outer portion 31 adjacent the edge 35 of the corner guard member 21 , and the first flat planar portion 25 further includes a first inner portion 33 adjacent the apex 22 of the corner guard member 21 . Additionally, the second flat planar portion 26 includes a second outer portion 32 adjacent the other edge 36 of the corner guard member 21 , and the second flat planar portion 26 further includes a second inner portion 34 also adjacent the apex 22 of the corner guard member 21 . A first layer 23 of thermoplastic material forms a main substratum of the corner guard member 21 . In the areas of the first and second outer portions 31 and 32 , the first layer 23 has a primary thickness, herein designated a first thickness. In the areas of the first and second inner portions 33 and 34 , the first layer 23 has a reduced thickness, herein designated a second thickness. A second layer 24 of thermoplastic material is applied onto the areas of reduced thickness of the first layer 23 of thermoplastic material and thereby forms the first and second inner portions 33 and 34 of the corner guard member 21 . The second layer 24 of material has a thickness designated herein as a third thickness. When the second layer 24 is applied to the area of reduced thickness of the first layer, the total thickness of the corner guard member 21 in that area is equal to the primary thickness of the first layer of thermoplastic material. In other words, the first thickness of the first layer of thermoplastic material is equal to the second thickness of the first layer plus the third thickness of the second layer. The corner guard member 21 thereby has a constant thickness throughout its entire width.
[0026] The reduced thickness of the first layer is preferably, thought not necessarily, greater than one half of the primary thickness of the first layer. In other words, the second thickness is preferably greater that one half of the first thickness. The thickness of the second layer is preferably, though not necessarily, less than one half of the primary thickness of the first layer. In other words, the third thickness is preferably less than one half the first thickness. Thus, in a corner guard that has a primary thickness of, for example, 0.080 inches thick, the reduced thickness of the first layer of thermoplastic material, i.e., the second thickness, is preferably about 0.045 inches thick, and the thickness of the second layer of thermoplastic material, i.e., the third thickness, is preferably about 0.035 inches thick. Of course, the actual thickness of the materials may be modified depending on the particular material used and its application.
[0027] The first and second layers of thermoplastic material are comprised of two different colors of material. Furthermore, the second layer 24 is applied over the first layer 23 in a manner that will expose both layers of material, and thus both colors to view from the hallways. In reference to FIG. 3, the corner guard member 23 has an outer surface 27 and an inner surface 28 . On the inner surface 28 , the first layer 23 extends completely from one side edge 35 of the corner guard to the other side edge 36 . The second layer 24 is applied onto outer surface of the first layer. Consequently, the first layer 23 of the first color of thermoplastic material is exposed to the outer surface 27 of the corner guard member 21 in the area of the first outer portion 31 of the first flat planar portion 25 and it is exposed in the area of the second outer portion 32 of the second flat planar portion 26 . Additionally, the second layer 24 of the second color of thermoplastic material is exposed to the outer surface 27 of the corner guard member 21 in the area of the first inner portion 33 of the first flat planar portion 25 and it is exposed in the area of the second inner portion 34 of the second flat planar portion 26 .
[0028] The relative widths of the inner and outer portions of the corner guard member, which are composed of the first and second colors of thermoplastic material, are preferably proportioned to provide a visual balance between the two colors. The relative widths are actually visually balanced better when the width of the inner portions is slightly less than the width of the adjacent outer portion. In a corner guard member that is, for example, three inches wide, meaning that the distance from the corner apex to the edge of the corner guard member measures three inches, the width of the inner portion is preferably about one-and-three-eighths inches wide (1⅜ inches), and the width of the outer portion is preferably about one-and-five-eighths inches wide (1⅝ inches). Because the inner portions are adjacent to each other, together they appear to be proportionally equal to the combined widths of the two outer portions of the corner guard member. The actual widths can of course be modified depending on the particular application of materials and the particular colors used.
[0029] The multi-colored corner guard of the present invention may be fastened to the corner of the building wall with conventional double-sided, pressure sensitive adhesive tape. Referring to FIG. 5 in particular, the inner surface 28 of the corner guard member 21 is provided with two strips of adhesive tape. Specifically, a first strip 41 of adhesive tape is applied onto the inner surface 28 of the first flat planar portion 25 of the corner guard member 21 , and a second strip 42 of adhesive tape is applied onto the inner surface 28 of the second flat planar portion 26 of the corner guard member. The corner guard is applied to the corner of a building wall by removing the liner on the adhesive and pressing the apex 22 of the corner guard member 21 tightly against the corner 10 of the building wall and thereby bonding the first flat planar portion 25 to the first wall surface 11 and further bonding the second flat planar portion 26 to the second wall surface 12 .
[0030] A second embodiment of the corner guard of the present invention is illustrated on FIG. 6. In FIG. 6, a corner guard assembly 120 is comprised of a retainer member 121 , a plurality of fasteners 122 for fastening the retainer member to the corner 110 of the building wall, a corresponding cover member 123 assembled over the retainer member, and end caps 124 assembled to the upper and lower ends of the assembly.
[0031] The retainer member 121 is an elongated member including a first flat planar portion 125 and a second flat planar portion 126 , the two flat planar portions each extending the entire length of the retainer member. The first flat planar portion 125 is applied over the first wall surface 111 , and the second flat planar portion 126 is applied over the second wall surface 112 . The first flat planar portion 125 intersects the second flat planar portion 126 preferably at an angle that corresponds to the angle of intersection of the first and second wall surfaces 111 and 112 , which normally should be about 90°. The retainer member 121 may be made from a metallic material, which is typically aluminum, or it may be made of a thermoplastic material, preferably an extruded polyvinyl chloride plastic material (PVC). In the construction of building walls, the two intersecting wall surfaces 111 and 112 that form the corner 110 are occasional assembled together in a manner that does not form a precise right angle. In that event, a retainer member 121 made from a thermoplastic material may be flexed a slight amount in order to properly fit over the corner 110 of the building wall to which the corner guard assembly 120 is being applied.
[0032] On the retainer member 121 , the first flat planar portion 125 has an offset edge portion 127 and the second flat planar portion 126 has a similar second offset edge portion 128 . When the retainer member 121 is applied to the corner 110 of the wall, the first offset edge portion 127 is raised a slight distance from the surface of the first wall surface 111 of the building wall. Likewise, the second offset edge portion 128 is raised a slight distance away from the second wall surface 112 . The first and second raised edge portions 127 and 128 form edges around which the cover member 123 is assembled. The retainer member 121 is fastened to the corner 110 of the building wall as illustrated in FIG. 6 with a plurality of fasteners 122 , preferably self-tapping screws
[0033] The cover member 123 is comprised of a first flat portion 131 and a second flat portion 132 , the first and second flat portions intersecting at a rounded corner portion 130 . The cover members 123 further includes a first inwardly turned, hooked shaped end portion 133 on the edge of the first flat surface 131 , which hooks around for engagement to the first raised edge portion 127 of the retainer member 121 . Likewise, a second inwardly turned, hooked shaped end portion 134 on the edge of the second flat surface 132 of the cover member 123 hooks around for engagement over the second raised edge portion 128 of the retainer member 121 . Being vinyl, the cover member 123 is capable of deforming a slight amount to bend the two hook shaped end portions 133 and 134 apart from each other to fit over the opposing edges 127 and 128 of the retainer member 121 , and then return to its original shape. Accordingly, the cover member 123 snaps in place and fits snugly over the retainer member 121 . End caps 124 are applied to the upper and lower ends of the corner guard assembly.
[0034] Aside from the structural differences that make the cover member 123 capable of attachment to the retainer member 121 , the cover member 123 illustrated in FIG. 6 is constructed in substantially the same manner as the corner guard member 20 discussed above and illustrated in FIGS. 1 - 5 . That is, the first flat portion 131 of the cover member 123 illustrated in FIG. 6 is likewise comprised of a first outer portion 135 adjacent the edge of the cover member 123 , and further comprised of a first inner portion 137 adjacent the rounded corner portion of the cover member 123 . The second flat portion 132 is similarly comprised of a second outer portion 136 adjacent the other edge of the cover member 123 , and further comprised of a second inner portion 138 also adjacent the rounded corner portion of the cover member 123 . The cover member 123 is further comprised of a first layer of thermoplastic material that forms a main substratum, and a second layer of thermoplastic material of a different color applied over the first layer in a manner that will expose both layers of material, and thus both colors to view from the hallways.
[0035] A third embodiment of the corner guard 220 of the present invention is illustrated in FIG. 7. The corner guard member 221 has a first flat planar portion 225 and a second flat planar portion 226 , which intersect each other at an apex 222 . The corner guard member 221 is identical to the first preferred embodiment of the corner guard member 21 except that a second layer 224 is applied to a first layer 223 at only one of the first flat planar portion 225 and the second flat planar portion 226 . Elements of the corner guard 220 of FIG. 7 corresponding to elements of the corner guard 20 of FIGS. 1 - 5 are, accordingly incremented by 200. In a preferred embodiment, the second thermoplastic layer is applied to the entire length of one of the planar portions 225 , 226 . This results in the first color being present on one side of the corner guard member 221 and the second color being present on the other side of the corner guard member 221 . An advantage of this is that one hallway can be color coded with a first color and an intersecting hallway can be color coded with another color. This is particularly useful in situations where hallways are color coded to indicate, for example, a route or a wing designation within a building.
[0036] The at least two colors of thermoplastic material of the corner guard member 221 are simultaneously co-extruded and bonded together in order to form a single integrated product. The corner guard member 221 of the present invention may be fabricated by thermo-bonding the first layer 223 of a first color thermoplastic material to the second layer 224 of a second color of thermoplastic material. Additionally, the layers are bonded to each other so that the final product has a constant thickness across its entire width.
[0037] A fourth embodiment of the corner guard of the present invention is a corner guard assembly and is like that illustrated on FIG. 6. However, in the fourth embodiment, the cover member is comprised of a first layer of thermoplastic material that forms a main substratum, and a second layer of thermoplastic material of a different color applied over the first layer in a manner that will expose a first layer of material on one side of the cover member and a second layer of material on the other side of the cover member.
[0038] The corner guards 20 and 220 and corner guard assemblies 120 disclosed herein may used as individual elements of a wall protection system, or used as components of a wall protection and color-coded marking system for both protecting the wall surfaces from damage and also for making specified locations within the building. Referring to FIG. 1, a wall protection and color-coded marking system may be comprised of color coordinated handrails, wall cove base and corner guards. The system may be comprised, for example, of a first handrail 14 and a first wall cove base 15 of a first color in a first hallway, a second handrail 16 and second wall cove base 17 of a second color in a second hallway, and a corner guard 20 of the present invention wherein the outer portions of the corner guard are of the first color, which matches the color of the first handrail and first wall cove base, and the inner portions of the corner guard are of the second color, which matches the color of the second handrail and second wall cove base. The colors of the walls 11 and 12 may also be coordinated to match the colors of the various components.
[0039] The multi-colored, co-extruded corner guard disclosed herein has a very desirable aesthetic appearance. Additionally, it may be used as part of a comprehensive system for designating and marking portions of buildings with color-coded components that also serve to protect the walls from damage. Of course, specific structural details disclosed above are not to be interpreted as limiting the scope of the invention, but represented merely as a basis for the claims and for teaching one skilled in the art to employ the present invention in any appropriately detailed structure. Changes may be made in the specific structural details of the particular embodiment disclosed above without departing from the spirit of the invention, especially as defined in the following claims.
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A corner guard assembly for protecting the corner of a building wall particularly in institutional type facilities from damage due to impacts with wheeled vehicles includes an elongated vinyl corner guard member angled to fit over the corner formed by the intersection of two wall surfaces, the corner member being comprised of two different colors of vinyl plastic material that have been co-extruded to form a single, integrated product. The multi-colored corner guard provides an aesthetically improved corner guard that may be used in a wide range of interior designs. Additionally, the improved corner guard disclosed herein may be used a part of a system of color-coding the hallways of a large hospital or other institutional facility. The corner guard of the present invention may be constructed as either a tape-on corner guard that is mounted by an adhesive directly to the wall surfaces, or constructed as an assembly comprised of a base plate and cover guard.
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This application is a continuation-in-part of application Ser. No. 231,217 filed Aug. 11, 1988 now abandoned.
BACKGROUND OF THE INVENTION
Several invasive and noninvasive techniques are used to assess patients with known or suspected coronary artery disease. Included among the noninvasive methodologies are electrocardiography, radionuclide angiography (first pass and equilibrium studies utilizing, for example, technecium 99 m labeled red blood cells), myocardial perfusion scintigraphy (utilizing positron emitting radiopharmaceuticals, for example, thallium-201, rubidium-82, nitrogen-13), and echocardiography (M mode and two dimensional). The manifestations of coronary artery disease are a function of the balance between myocardial oxygen supply and demand. Although these noninvasive procedures may be performed in a resting subject, there may not be sufficient imbalance between supply and demand to detect abnormalities at rest. Therefore, provocative studies are frequently performed to improve the predictive accuracy of these diagnostic procedures. The most commonly employed provocative (stress) technique utilizes a standard exercise protocol. Under conditions of exercise myocardial oxygen demand is increased to exceed supply. This form of stress testing is commonly employed in conjunction with electrocardiography, radionuclide angiography, myocardial perfusion scintigraphy, echocardiography, and contrast ventriculography.
Recently, provocative studies have been developed utilizing pharmacological techniques designed to increase myocardial oxygen supply. Specifically, coronary vasodialators (e.g. nitrates, papavarine, dipyridamole, etc.) have been used for this purpose, although none have been approved by the FDA for this specific indication. While the mechanism is not clear, these agents may dilate normal vessels to a greater extent than diseased vessels, establishing a shunt or "myocardial steal". Pharmacological provocation may be particularly useful in patients who are unable to exercise, and may be equal to or superior to exercise provocation in patients capable of exercising. Furthermore, since exercise increases demand and coronary vasodilators increase supply, it is possible that the highest diagnostic yield will accrue when they are used in conjunction with one another.
Coronary arteriography is an invasive procedure which currently represents the "gold standard" for confirming the diagnosis of coronary artery disease. However, this procedure only establishes the anatomical severity of the disease and provides little information concerning the functional significance of visible lesions. Furthermore, small vessel disease may be present and beyond the resolution of currently available equipment. Recently, in an attempt to establish the functional significance of coronary lesions, coronary vasodilators have been administered by intracoronary injection or intravenous infusion and coronary blood flow is measured by one of several techniques, such as doppler flow catheters, videodensitometry, coronary sinus thermodilution, and radionuclide clearance of inert gases. These techniques are becoming more widely used to measure coronary flow reserve (i.e. reserve capacity) which provides important information concerning the functional significance of stenotic vessels. Although nitrates, papavarine, and dipyridamole have been used by some physicians for this purpose, no vasodilator has been approved by the FDA for this specific indication. The use of adenosine, 1-methyl-2-phenylethyl-adenosine, 5-ethyl carboxamide adenosine, cyclopentyl adenosine 2-chloro adenosine, adenine, inosine, adenosine monophosphate, adenosine diphosphate, or adenosine triphosphate, in conjunction with the above stated techniques to measure coronary flow reserve and assess the functional severity of stenotic vessels represents a novel application (indication) of our compound.
SUMMARY OF THE INVENTION
Briefly, the present invention comprises a method of detecting the presence or assessing the severity of vascular disease which includes the administration to the human host of an effective dilating amount of adenosine; functional adenosine receptor agonists (e.g., 1-methyl-2-phenylethyladenosine, 5-ethyl carboxamide adenosine, cyclopentyl adenosine or 2-chloro adenosine); metabolic precursors or byproducts of adenosine (e.g., adenine and inosine); and phosphorylated derivatives of adenosine (e.g., adenosine monophosphate, adenosine diphosphate, or adenosine triphosphate), in conjunction with invasive or noninvasive techniques.
It is an object of this invention to provide a new diagnostic method to aid in the determination of the extent and severity of heart disease.
It is a further object of this invention to provide a new radioimaging technique for the coronary arteries.
More particularly, it is one object of this invention to provide an improved method of radioimaging the coronary arteries.
It is one significant object of this invention to provide wash out times for the radiolabeled agents used in stress-free cardiac imaging which are comparable to the wash out times presently attainable only in stress or exercise radioimaging tests.
These and other objects and advantages will be apparent from the more detailed description which follows.
DETAILED DESCRIPTION OF THE INVENTION
Adenosine is chemically designated as 9-β-D- ribofuranosyl-9H-purine-6-amine; 6-amino-9-β-D-ribofuranosyl-9H-purine; 9-β-D-ribofuranosidoadenine; adenine riboside.
Adenosine is a nucleoside widely distributed in nature. factured from yeast nucleic acid. It is practically insoluble in alcohol. Crystals form from water, mp 234°-235°. [α] 11 -61.7° (c=0.706 in water; [α] 9 -58.2° (c=658 in water). uv max: 260 nm (ε15,100).
The structural formula is as follows: ##STR1##
This invention utilized adenosine administration as a pharmacological stressor in conjunction with any one of several noninvasive diagnostic procedures available. For example, intravenous adenosine may be used in conjunction with thallium-201 myocardial perfusion imaging to assess the severity of myocardial ischemia. In this case, anyone of several different radiopharmaceuticals may be substituted for thallium-201 (e.g. rubidium-82, technitium 99m, derivatives of technitium 99m, nitrogen-13, iodine 123, etc.). Similarly, adenosine may be administered as a pharmacological stressor in conjunction with radionuclide angiography to assess the severity of myocardial dysfunction. In this case, radionuclide angiographic studies may be first pass or gated equilibrium studies of the right and/or left ventricle. Similarly, adenosine may be administered as a pharmacological stressor in conjunction with echocardiography to assess the presence of regional wall motion abnormalities. Similarly, adenosine may be administered as a pharmacological stressor in conjunction with invasive measurements of coronary blood flow such as by intracardiac catheter to assess the functional significance of stenotic coronary vessels.
This invention typically involves the administration of adenosine by intravenous infusion in doses which are effective to provide coronary artery dilation (approximately 20-200 mcg/kg/min). However, its use in the invasive setting may involve the intracoronary administration of the drug in bolus doses of 2-20 mcg. The adenosine used in this invention is normally admixed with any pharmaceutically suitable carrier or carriers such as saline, dextrose, water, or any other carrier customarily used for the type of administration intended. The solution may contain the active ingredient in a widely varying amount, for example, from about 1 mg/ml to about 12 mg/ml.
These doses increase coronary flow approximately 4-5 times resting values. Unlike papavarine which in this setting frequently causes QT interval prolongation, significant electrocardiographic or systemic hemodynamic abnormalities have not been observed. Adenosine is a superior vasodilator for this purpose.
The practice of this invention is applicable to radiopharmaceuticals generally, and specifically to those mentioned hereinabove.
Contemplated as equivalents of adenosine in the practice of this invention are analogues, derivatives, metabolic precursors or by-products or conjugates intended to function as agonists of the adenosine receptor responsible for mediating vasodilation. This appears to be the A 2 receptor subtype. Several analogues of adenosine have been developed which appear to have greater affinity or specificity for the A 2 receptor. These include primarily the N 6 substituted derivatives and the 2-carbon derivatives such as 1-methyl-2-phenylethyl-adenosine, 5-ethyl carboxamide adenosine, cyclopentyl adenosine, 2-chloro adenosine, etc.
The following methods are preferred embodiments of our invention.
The method comprising the use of an agent which is adenosine, functional adenosine receptor agonists, metabolic precursors or by-products of adenosine, or phosphorylated derivatives of adenosine as a substitute for exercise in conjunction with myocardial perfusion imaging to detect the presence and/or assess the severity of coronary arter disease in humans wherein myocardial perfusion imaging is performed by any one of several techniques including radiopharmaceutical myocardial perfusion imaging, planar (conventional) scintigraphy, single photon emission computed tomography (SPECT), positron emission tomography (PET), nuclear magnetic resonance (NMR)imaging, perfusion contrast echocardiography, digital subtraction angiography (DSA), or ultrafast x-ray computed tomography (CINE CT).
The method comprising the use of an agent which is adenosine, functional adenosine receptor agonists, metabolic precursors or by-products of adenosine, or phosphorylated derivatives of adenosine as a substitute for exercise in conjunction with imaging to detect the presence and/or assess the severity of ischemic ventricular dysfunction in humans wherein ischemic ventricular dysfunction is measured by any one of several imaging techniques including echocardiography, contrast ventriculography, or radionuclide angiography.
The method comprising the use of an agent which is adenosine, functional adenosine receptor agonists, metabolic precursors or by-products of adenosine, or phosphorylated derivatives of adenosine as a coronary hyperemic agent in conjunction with means for measuring coronary blood flow velocity to assess the vasodilatory capacity (reserve capacity) of coronary arteries in humans wherein coronary blood flow velocity is measured by any one of several techniques including Doppler flow catheter, digital subtraction angiography or other radiopharmaceutical imaging technique.
The following Examples are to illustrate the invention, and are not intended to limit the invention.
EXAMPLE I
As set forth in this example, the effects of intravenous adenosine as a pharmacological stressor in conjunction with thallium 201 scintigraphy were evaluated. In the first set of experiments, adenosine was compared to exercise in a crossover study design using planar (conventional) thallium 201 scintigraphy in a population of 20 healthy normal volunteers. In the second set of studies, adenosine was compared to dipyridamole in a crossover study design using planar (conventional) thallium 201 scintigraphy in a population of 26 subjects (12 healthy volunteers and 14 patients with angiographically documented coronary artery disease). In the third set of experiments, adenosine was evaluated using thallium 201 single-photon emission computed tomography (SPECT) in a population of 33 patients (18 normal subjects and 15 patients with angiographically documented coronary artery disease).
In the first set of experiments, 20 healthy normal volunteers (age 19-39 years) underwent planar (conventional) stress/redistribution thallium 201 scintigraphy twice (in a random crossover design). One study employed maximum treadmill exercise (Bruce protocol) as the method of stress and the other study employed an intravenous infusion of adenosine as the method of stress. Heart rate, blood pressure and a 12-lead electrocardiogram were monitored throughout the study. The exercise stress test was conducted in standard fashion. The adenosine stress test employed a constant infusion of adenosine initiated at 20 mcg/kg/min. The infusion was doubled at intervals to a maximum dose of 140 mcg/kg/min. The maximum tolerable dose was administered for at least 5 minutes prior to a single bolus injection of thallium 201 (approximately 2.0 mCi). Early (stress) imaging was performed 5-10 minutes after the thallium injection and delayed (redistribution) imaging was performed 3-4 hours after thallium injection. The adenosine infusion was continued to the end of early imaging. Early and delayed imaging each consisted of 3 sets of images (left arterior oblique, anterior and left lateral projections). The images were acquired and reconstructed in standard fashion. The adenosine infusion was well tolerated in all subjects. The exercise stress images and the adenosine stress images were interpreted as normal (i.e., no perfusion defect detected) in all subjects. This experiment indicates that adenosine compares favorably to exercise in detecting normalcy by planar thallium 201 scintigraphy.
In the second set of experiments, 12 healthy normal volunteers and 14 patients with angiographically documented coronary artery disease underwent planar (conventional) stress/redistribution thallium 201 scintigraphy twice (in a random crossover design). One study employed oral dipyridamole (300 mg) as the method of stress and the other study employed an intravenous infusion of adenosine as the method of stress. Dipyridamole stress imaging was performed in standard fashion and adenosine stress imaging was performed as described above. Again, the adenosine infusion was well tolerated in all subjects. The sensitivity, specificity and overall predictive accuracy for detection of coronary artery disease was 88.8%, 87.5% and 88.0%, respectively, with adenosine imaging, and 77.7%, 82.6% and 80.5%, respectively, with dipyridamole imaging. The positive predictive value of adenosine and dipyridamole imaging was 84.2% and 77.7% respectively. This study indicates that adenosine imaging is safe and may be superior to dipyridamole imaging for the accurate detection of angiographically significant coronary artery disease.
In the third set of experiments, 15 patients with angiographically documented coronary artery disease and 18 subjects with either angiographically normal coronary arteries (n=8) or healthy normal volunteers (n=10) underwent thallium 201 myocardial perfusion imaging using single photon emission computed tomography (SPECT). In all subjects, only an infusion of adenosine was employed as a method of stress. The adenosine infusion was initiated at 50 mcg/kg/min and titrated at 1 minute intervals by increments of 25 mcg/kg/min to a maximum dose of 140 mcg/kg/min. The maximum tolerable dose was maintained for at least 1 minute prior to and 3 minutes subsequent to a single bolus injection of thallium 201 (approximately 3.0 mCi). Early (stress) imaging was performed 5-10 minutes post-thallium and delayed (redistribution) imaging was performed 3-4 hours post-thallium. The SPECT images were acquired and reconstructed in standard fashion. Side effects occurred in 76% of the subjects, but were usually mild, did not require therapy and ceased instantly after discontinuing the adenosiene infusion. Chest pain occurred in 53%, headache in 34% and cutaneous flushing in 15%. Dose-dependent decreases is systolic blood pressure (hypotension) and reflex increases in heart rate were common. Perfusion defects were detected during adenosine stress imaging in all 15 patients with known coronary artery disease and these defects were reversible in 9 (sensitivity =100%). The adenosine stress images were interpreted as normal in 16 of 18 presumed healthy subjects (specificity =89%). This study indicates that adenosine-induced coronary vasodilation is a safe, convenient, and potent intervention to uncover perfusion defects during SPECT thallium scintigraphy in patients with coronary artery disease.
EXAMPLE II
As set forth in this example, the effects of intravenous adenosine as a pharmacological stressor in conjunction with echocardiography were evaluated.
Fifteen patients with a positive exercise (stress) SPECT thallium 201 tomogram were selected for this study. The tomographic perfusion defect was fixed (irreversible) in 6 subjects and reversible in 9 subjects. Subsequently, these patients underwent standard 2-dimensional echocardiographic studies under conditions of rest (baseline) and during an intravenous infusion of adenosine as previously described (Example I, 3rd set of experiments). Echocardiographic studies were performed over a 1 minute period prior to the adenosine infusion (baseline), during maximum adenosine infusion (140 mcg/kg/min), and 3 minutes after the cessation of the adenosine infusion. All echocardiographic studies included parasternal views (long axis and short axis at the level of the mitral valve, papillary muscles and apex) and apical views (4-chamber, 2-chamber and apical long axis). All echocardiogrpahic images were interpreted by standard qualitative and quantitative techniques. The echocardiographic images obtained at rest were interpreted as normal in all subjects. However, left ventricular wall motion abnormalities were detected during adenosine (stress) studies in all 6 patients with fixed thallium perfusion defects. Left ventricular wall motion remained normal during the adenosine infusion in all patients with reversible thallium perfusion defects. This study indicates that adenosine may be a useful pharmacological stressor for the detection if ischemic ventricular dysfunction as assessed by echocardiography.
EXAMPLE III
As set forth in this example, the effects of intravenous and intracoronary adenosine as a pharmacological stressor in conjunction with measurements of coronary blood flow reserve (CBFR) were evaluated at the time of coronary arteriography using a Doppler flow catheter.
Ten patients with an angiographically normal left coronary artery were studied at the time of diagnostic coronary arteriography. A 3F Doppler catheter was positioned in the left coronary artery to measure coronary blood flow velocity (CBFV), and mean arterial pressure, heart rate and the ECG were simultaneously recorded. Following repeated measures of baseline CBFV, incremental doses of intracoronary papaverine (8-12 mg boluses), intracoronary adenosine (4-14 mcg boluses) and intravenous adenosine (70-140 mcg/kg/min infusions) were administered in crossover fashion. Each drug was titrated to the maximum coronary hyperemic response. While the ECG intervals were unchanged during adenosine administration, papaverine routinely prolonged the QT interval (mean 96±18 msec). Relative to papaverine, maximum coronary hyperemic responses (4-5 fold increases in CBFV) were achieved with 14 mcg intracoronary bolus doses of adenosine, as well as 140 mcg/kg/min intravenous infusions of adenosine. Compared to papaverine, maximal coronary hyperemia occurred sooner with adenosine (10 vs 20 seconds) and resolved sooner with adenosine (37 vs 118 seconds), consistent with its ultrashort half-life. This study indicates that maximal coronary hyperemia can be achieved with either intracoronary or intravenous adenosine and may be a useful technique to assess the vasodilatory reserve capacity (i.e., functional significance) of stenotic coronary vessels.
ADVANTAGES OF THIS INVENTION OVER CONVENTIONAL TECHNIQUES
Certainly, adenosine and the other analogs mentioned hereinabove as a pharmacological stressor have the advantage over exercise as a stressor in patients who are unable or are unwilling to exercise at a work load appropriate for the noninvasive assessment of coronary artery disease. It remains to be determined whether these compounds as a pharmacological stressor are superior to exercise as a stressor in the assessment of coronary artery disease among patients capable of exercising. Although no coronary vasodilators have been approved by the Food and Drug Administration for this indication, adenosine and the related compounds identified above possess several advantages over the other conventional agents such as, nitrates, papavarine, and dipyridamole. First, adenosine has an ultra short half-life (less than 20 seconds). As a result, its onset of action and clearance from the body are rapid and the time required to perform the procedure is shortened. Furthermore, side effects when they occur are rapidly controlled by reducing the infusion rate and rarely require discontinuing the infusion or treating with theophylline. Second, adenosine is an endogenous substance in humans and should not result in allergic reactions.
Having fully described the invention it is intended that it be limited solely by the lawful scope of the appended claims.
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The parenteral use of adenosine, functional adenosine receptor agonists which include 1-methyl-2-phenylethyladenosine, 5-ethyl carboxamide adenosine, cyclopentyl adenosine and 2-chloro adenosine; metabolic precursors or by-products of adenosine which include adenine and inosine; and phosphorylated derivatives of adenosine including adenosine monophosphate, adenosine diphosphate and adenosine triphosphate in conjunction with various invasive and noninvasive diagnostic techniques to detect the presence or assess the severity of vascular disease is a novel application (indication) for these compounds and forms the basis of this patent application.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This patent application claims priority to and is a continuation application of U.S. application Ser. No. 10/978,961, filed on Nov. 1, 2004, which is a continuation in part application of U.S. application Ser. No. 10/331,407, filed on Dec. 30, 2002, which is a continuation in part application of U.S. application Ser. No. 09/736,598, filed on Dec. 13, 2000, and of which the entire contents of each are hereby incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to a retaining wall block that is resistant to damage and wear caused by the environment it is placed into. The deterioration resistant block is generally a hollowed frame or shell of a deterioration resistant material that is light-weight and is configured to accept and retain any type of filling material. The filling material provides weight and stability to the retaining wall block and also provides weight, stability and security to a retaining wall constructed of such blocks.
BACKGROUND OF THE INVENTION
[0003] The use of retaining walls to protect and beatify property in all types of environmental settings is a common practice in the landscaping, construction and environmental protection fields. Walls constructed from various materials are used to outline sections of property for particular uses, such as gardens or flower beds, fencing in property lines, reduction of erosion, and to simply beautify areas of a property.
[0004] Numerous methods and materials exist for the construction of retaining walls. Such methods include the use of natural stone, poured in place concrete, masonry, landscape timbers or railroad ties. In recent years, segmental concrete retaining wall units, sometimes known as keystones, which are dry stacked (i.e., built without the use of mortar), have become a widely accepted product for the construction of retaining walls. Examples of such units are described in U.S. Pat. No. RE 34,314 (Forsberg) and in U.S. Pat. No. 5,294,216 (Sievert).
[0005] However, many of the materials utilized in the construction of retaining walls are susceptible to deterioration and/or are not very aesthetically appealing. The ability of these retaining walls to withstand sunlight, wind, water, general erosion and other environmental elements is a problem with most retaining wall products.
[0006] A particular concern is the utilization of erosion protection materials in water shorelines. Leaving the shoreline natural can lead to erosion, cause an unmanageable and unusable shoreline, create high maintenance, and inhibit an aesthetically pleasing property. Many materials utilized in retention of shorelines are subject to immediate deterioration and/or are not as aesthetically appealing as one would desire. Furthermore, many materials utilized on shoreline structures are difficult to maintain due to the awkward location in the water and also the prevalent growth and presence of organic materials that can get caught and flourish in such a structure. For example, many lakeshore or ocean side properties utilize riprap as a retention device for prevention of erosion. Riprap is a configuration of large to medium size stones placed along the shoreline. A problem with waterfront properties that use a continuous wall of typical riprap is the shoreline will retain some organic material or will accumulate additional organic material brought in by the water. This usually leads to an unmanageable and aesthetically displeasing shoreline or higher maintenance. Furthermore, the riprap is never uniform in color and size and therefore does not as provide the most aesthetically pleasing shoreline or complete coverage of the shoreline. The lack of uniform shoreline coverage allows for some erosion, collection of various materials and the growth of weeds.
[0007] Another problem with materials normally utilized in the construction of retaining walls, such as poured in place concrete, masonry, landscape timbers, railroad ties or keystones is that regulations in most states and counties prohibit their use in or near bodies of water because of the crumbling or deterioration of the material into the body of water over time. Many of these retaining wall materials dissolve, crumble, break apart and/or float into the body of water for which they line causing problems with the shoreline and pollution of the water. For example, the average life of a concrete block or keystone in water is approximately a couple of years. A need exists for a retaining wall, which would be resistant to such deterioration.
[0008] An additional concern that exists in the construction of retaining walls is the weight of the materials. Concrete blocks, large stones, timbers or keystones can be heavy to move into the wall location and maneuver when constructing the wall. Many locations for which retaining walls are constructed are positioned in awkward terrain. Heavy building materials are difficult to move into the location and furthermore are difficult to position when constructing the retaining wall thereby adding additional cost and labor for installation. However, the heavy materials are needed once the wall is constructed to provide stability and security to the structure. Therefore, the easy to install light-weight units used for the construction of a retaining wall, which can be weighted once placed into position thus retaining the block in position and stabilizing the completed retaining wall, would be beneficial to construction of such structures.
SUMMARY OF THE INVENTION
[0009] As previously mentioned the present invention relates to a retaining wall block that is resistant to damage and wear caused by the environment it is placed into. The deterioration resistant block is generally a hollowed frame or shell of a deterioration resistant material that is light-weight and is configured to accept and retain any type of filling material. The filling material provides weight and stability to the retaining wall block and also ultimately provides stability and security to the retaining wall constructed of such blocks. More specifically, the deterioration resistant block comprises a top panel, a bottom panel, a wall assembly and an optional anchoring device. One or more chambers are created by adjoining the top panel, bottom panel and wall assembly. The chambers are adapted for receiving and retaining fill materials. such as sand, dirt, gravel, pea rock, crushed rock, concrete or any other similar material, which provides the permanent weighting and stability of the retaining wall block.
[0010] Embodiments of the present invention are comprised of a deterioration resistant retaining block for use in constructing retaining walls on a number of property terrains, such as along waterfront properties. The deterioration resistant blocks are particularly useful for terrains near water or underwater due to their resistance to degradation. However, the deterioration resistant blocks could also be used for land applications for those that want a light-weight retaining wall block that can be filled on-site to add weight and stability and doesn't require heavy equipment for moving. Therefore, the deterioration resistant retaining wall block could be utilized to construct any form of wall or fence structure.
[0011] One unique feature of the present invention is the lightweight characteristic of the block before it is filled. As previously mentioned, embodiments of the present invention can be waterproof and may be filled with any type of fill material located at the site, such as rocks, sand, gravel, soil, pea rock, crushed rock or similar materials. The filling characteristic of the deterioration resistant block means that when the block is not filled it is very light-weight. The light-weight feature provides individuals constructing such walls the advantage of easily moving large numbers of the blocks to the site of construction with relative ease. Furthermore, the lightweight characteristic of the blocks allows for easy maneuvering of the blocks into final position when constructing the wall and still allows for the stability of a heavy block after it is filled. These characteristics are met by the block being made of a lightweight material and also configured to receive a heavy fill material once it is about to be placed or has been placed in its final position on the retaining wall.
[0012] Embodiments of the present invention further fills an unmet landscaping need for shorelines in that the deterioration resistant blocks are easily manufactured. Examples of possible manufacturing methods include but are not limited to injection-molding, thermoforming, compression molding and blow-molding. Also any high volume application for production may be utilized in manufacturing the present invention. The individual units are light-weight, attractive, easy to install, prevent shoreline and other terrain erosion and compliment existing retaining wall block. The deterioration resistant blocks are also waterproof, can withstand ice damage due to their flexible nature and are easily replaced in case of damage. Furthermore, they are rugged and very low maintenance. Additionally, embodiments of the present invention are easily transportable and storable due to their light-weight and possible stacking features.
[0013] Individuals would be more inclined to install block made of a deterioration resistant material themselves rather than cement block, timbers, keystones and the like, because of the ease of installation, due to the lightweight material and also the longevity of the block. The minimum weight of most regular garden block is approximately 30-50 lbs, whereas embodiments of the present invention may be approximately 0.1-10 lbs, in various embodiments 1-2 lbs. Of course, weight may vary depending on the size and materials utilized in manufacturing embodiments of the present invention. Also, as previously mentioned the blocks of the present invention retain the final stability and weight by filling the block with an appropriate fill material either prior to or after it has been permanently installed.
[0014] As previously suggested, embodiments of the present invention are also resistant to deterioration, such as wear, crumbling and breaking, therefore, the deterioration resistant block does not have to be replaced as often and/or increases the lifespan of the retaining wall. The block has approximately the lifespan of at least 5-10 times the life of a regular cement block made by the dry cement process such as the Keystone® style retaining wall block. The increased lifespan of the block translates to fewer or no occurrences of replacement of individual blocks or the potential complete reconstruction of the entire wall. Furthermore, retaining wall materials, such as concrete block, timbers and dry cement process block, are typically not used in water applications because they dissolve, crumble and/or break down over time and exposure. The durability and resistant characteristics of the present invention reduce and prevent this deterioration, therefore making it very beneficial for all applications that come in contact with water.
[0015] Another consideration relating to the water application of embodiments of the retaining wall block of the present invention is the block's resistance to ice damage when installed around a body of water when it freezes. When ice expands and/or moves it shifts, tears and damages various types materials utilized for shoreline retention, such as keystone, concrete block, rip rap, landscape timbers or anything rigid. Embodiments of the present invention can be manufactured with a material that has flexibility and would flex in a similar way as a Rubbermaid® trash can flexes. Considering that the deterioration resistant block would be filled with a fill material, the deformation would be minimal, but still enough to prevent damage to the retaining wall block and/or the entire wall. Furthermore, upon melting or shifting of the ice the deterioration resistant block would return to its original configuration.
[0016] Another advantage of embodiments of the present invention relates to the high cost of waterfront property and people's inclination to improve their property to keep it well-maintained and aesthetically pleasing. As previously mentioned riprap, is commonly stacked along property shorelines to prevent erosion. The trouble with this shoreline preservation application is that the rock leaves many crevices for organic material to reside and, since it is close to water, the crevices are prominent areas for the growth of vegetation. The advantage of embodiments of the present invention is that they fit next to each other and prevent organic material from getting in-between the blocks, therefore preventing vegetation from growing in such structures.
[0017] In addition, many waterfront properties suffer water damage when water levels rise above the shoreline. The retaining wall block of the present invention is a solution to water retention and erosion problems in such areas of threatening high or rising water levels. Furthermore, the retaining wall block poses a solution in locations where there is a flood plane or areas that are washed out by any type of water movement. Sandbags have been a solution to such problems, but are not a permanent or aesthetically pleasing solution. The retaining wall block can replace sand bags in an area for which a more permanent and aesthetically pleasing alternative is desired.
[0018] As previously suggested, the deterioration resistant retaining wall block can comprise any type of shape, configuration, color and design. In addition the retaining wall block may include any design or color located anywhere on any panel or wall of the block. Furthermore, the utilization of conventional type materials for retaining walls, such as concrete blocks, timbers or concrete retaining wall blocks, are heavy to install and may not provide long term or permanent solutions, due to the previously mentioned deterioration problems. Therefore, the present invention provides an aesthetically pleasing solution and replacement for materials, including sandbags, presently utilized in retaining wall construction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 depicts a perspective view of one embodiment of a deterioration resistant retaining wall block.
[0020] FIG. 2A depicts a perspective view of one embodiment of a deterioration resistant retaining wall block that includes a split top panel having teeth.
[0021] FIG. 2B depicts a perspective view of one embodiment of a deterioration resistant retaining wall block that includes a split top panel having intertwining fingers.
[0022] FIG. 3 depicts a side view of a deterioration resistant retaining wall block, which includes a retaining flange.
[0023] FIG. 4 depicts a perspective view of one embodiment of a deterioration resistant retaining wall block that includes a wall reinforcement fastener in the form of rivets.
[0024] FIG. 4A depicts a side view of one embodiment of a deterioration resistant retaining wall block that includes a wall reinforcement fastener in the form of rivets on the top panel and flange.
[0025] FIG. 4B depicts a perspective view of one embodiment of a deterioration resistant retaining wall block that includes a wall reinforcement fastener in the form of tack strips.
[0026] FIG. 4C depicts a perspective view of one embodiment of a deterioration resistant retaining wall block that includes a wall reinforcement fastener in the form of a grid retention rod system.
[0027] FIG. 4D depicts a perspective view of one embodiment of a deterioration resistant retaining wall block that includes a geogrid fabric adjoined to the block.
[0028] FIG. 5A depicts a front view of a deterioration resistant retaining wall block, which includes insertable pegs.
[0029] FIG. 5B depicts a perspective view of deterioration resistant retaining wall blocks, which includes an aperture in the form of a trough for receiving lockable insertable pegs.
[0030] FIG. 6 depicts a perspective view of the bottom panel of a deterioration resistant retaining wall block, which includes insertable pegs.
[0031] FIG. 6A depicts a perspective view of the bottom panel of a deterioration resistant retaining wall block, which includes conduit insertable pegs that include protrusions.
[0032] FIG. 7 depicts a perspective view of the bottom panel of a deterioration resistant retaining wall block, which includes insertable pegs that slide within a mounting tray.
[0033] FIG. 8 depicts a perspective view of deterioration resistant retaining wall that depicts the pegs of one embodiment of a block being lowered into the apertures of two blocks positioned below.
[0034] FIG. 9A depicts a perspective view of deterioration resistant retaining wall that includes staggered rows and a stabilizing rod and geogrid system adjoined to the wall.
[0035] FIG. 9B depicts a perspective view of deterioration resistant retaining wall that includes staggered rows and molded designs on the front panel.
[0036] FIG. 10 depicts a perspective view of a deterioration resistant retaining wall block containing multiple chambers.
[0037] FIG. 11 depicts a top view of a multiple chamber deterioration resistant retaining wall block that includes a top panel with multiple apertures.
[0038] FIG. 12A depicts a perspective view of a cover of a deterioration resistant retaining wall block.
[0039] FIG. 12B depicts a perspective view of a cover with extended overlapping panels form fitted over a deterioration resistant retaining wall block.
[0040] FIG. 12C depicts a perspective view of a cover with an extended overlapping panel having a front face with an apron form fitted over a deterioration resistant retaining wall block.
[0041] FIG. 13A depicts a side view of a deterioration resistant retaining wall block including a hingedly attached cover.
[0042] FIG. 13B depicts a perspective view of a deterioration resistant retaining wall block including recessions for receiving tabs of a cover.
[0043] FIG. 13C depicts a side view of a deterioration resistant retaining wall block including a hingedly attached cover.
[0044] FIG. 13D depicts a side view of a deterioration resistant retaining wall block including a hingedly attached split cover.
[0045] FIG. 14 depicts a top view of a partial section of a deterioration resistant retaining wall block.
[0046] FIG. 14A depicts a perspective view of a block end cap.
[0047] FIG. 14B depicts a perspective view of one embodiment of a block including cap hooking devices.
[0048] FIG. 15 depicts a top view of a multi-unit deterioration resistant retaining wall block, which includes disengaging tabs.
[0049] FIG. 16 depicts a front view of a multi-unit deterioration resistant retaining wall block.
[0050] FIG. 17 depicts a top view of a multi-unit deterioration resistant retaining wall block with disengaged tabs.
[0051] FIG. 18 depicts a top view of a deterioration resistant retaining wall block that includes interlocking clips and pockets.
[0052] FIG. 19 depicts a perspective view of more than one stackable deterioration resistant retaining wall blocks.
[0053] FIG. 20 depicts a perspective view of one embodiment of a partial row of deterioration resistant capping blocks.
DETAILED DESCRIPTION OF THE INVENTION
[0054] FIG. 1 depicts one embodiment of the deterioration resistant retaining wall block 10 comprising a top panel 12 , a bottom panel 14 and a wall assembly 16 . FIG. 1 illustrates one embodiment of the present invention that includes a top split panel 12 , which includes a first section 18 and a second section 20 . It is noted that a number of embodiments included in the present invention may include a top panel 12 that is not split. The top split panel 12 may also include one or more apertures 22 . The apertures 22 may be of any size and shape suitable for receiving one or more anchoring devices as will be described below. The bottom panel 14 includes a relatively flat surface or contoured to rest uniformly with the top panel 12 of one or more blocks 10 positioned below. In other embodiments of the present invention the top panel 12 and bottom panel 14 may include apertures 22 that align with apertures positioned on the top panel and bottom panel of adjacent blocks above and below. Such alignment of apertures 22 allow for the intermingling of fill material that may add additional friction between the blocks and may provide a potential securing feature for geogrid fabric positioned between rows of blocks.
[0055] As previously mentioned, the deterioration resistant retaining block 10 also includes a wall assembly 16 , which is also depicted in FIG. 1 . The wall assembly 16 comprises one or more outside wall panels 24 . Many embodiments of the present invention include wall assemblies 16 that are adjoined to the top panel 12 and bottom panel 14 . The adjoinment of the wall assembly 16 to the top panel 12 and bottom panel 14 creates a chamber 26 located within the retaining block 10 . The chamber 26 is normally filled with materials such as sand, gravel, dirt, concrete, crushed rock, pea rock or other like materials to provide weight and structure stability to the retaining block 10 and the entire retaining wall.
[0056] Additionally, the wall assembly 16 will generally include a front face 17 that is visible to an observer when a wall is constructed from the blocks 10 of the present invention. In various embodiments of the present invention the front face 17 will have a natural earthen appearance simulating the color and texture of earth environments. For example, the front face may be colored and textured to have the appearance of rock, stone, sand, soil, clay, trees and foliage, water, or any other natural environment type look. Additionally, in additional embodiments the front face 17 may further include one or more designs (e.g. symbols, company names, logos, images) that may be positioned in the natural earthen appearance (e.g. the NTR logo embedded in a stone color and texture).
[0057] FIGS. 2A and 2B depict various embodiments of a top split panel 12 . As depicted in FIG. 2A , one embodiment of a top split panel 12 of the present invention comprises a second section 20 having a plurality of teeth 28 . The teeth 28 may extend downward from the second section 20 when in a closed position and may be utilized to engage one or more wall stabilization devices (not shown), such as geogrid or geowebbing. It is noted that the teeth 28 may be considered a wall reinforcement fastener (a further explanation of wall reinforcement fasteners will be described below). The second section 20 may abut flush to the front edge of the first section 18 of the top split panel 12 as illustrated in FIG. 1 or may overlap and/or engage the first section 18 . One embodiment of the engagement of the top panel section is depicted in FIG. 2 a . As depicted in FIG. 2 a , the first section 18 may include a plurality of notches 30 , which receive and engage the teeth 28 of the second section 20 when the split top panel 12 is in the closed position.
[0058] FIG. 2B illustrates another embodiment of the present invention wherein the top split panel 12 includes a first section 18 and a second section 20 with intertwining fingers 32 that alternate with each other when the top split panel 12 is in the closed position.
[0059] In various embodiments of the present invention, the bottom panel 14 may optionally include or be adjoined to a flange 34 . FIG. 3 depicts the side view of an embodiment of the present invention, which includes a retaining flange 34 adjoined to the bottom surface 14 of the block 10 . On a constructed wall, each retaining flange 34 is a wall retention device that operates to align the block being placed with the row below and generally inhibits outward movement of the wall. Normally, the retaining flange 34 extends downward from the back of the bottom panel 14 and rests against the back of the retaining block 10 located below the bottom panel 14 . The retaining flange 34 may be a unitary piece extending downward from the back of the retaining block 10 or may be a series of fingers (not shown) extending downward from the back of the retaining block 10 .
[0060] The retaining block 10 of the present invention may also include a means for attaching wall stabilization devices, such as geogrid. FIG. 4 depicts one embodiment of a wall reinforcement retention device 38 comprising a plurality of rivets 40 operably adjoined to the front section 20 of the top panel 12 of a retaining wall block. FIG. 4A depicts an embodiment of the block including the rivets 40 positioned on the top panel 12 and flange 34 . However, it is noted that the rivets 40 may be positioned anywhere on the block, which is optimum to hook and retain the webbing of a geogrid or other device that extends back from the wall into the slope being protected. The rivets may be of any size and shape, which optimize the attachment of the geogrid or other devices reinforcing the wall structure.
[0061] FIG. 4B depicts another embodiment of a wall reinforcement retention device 38 in the form of tack strips 42 . Tack strips 42 generally include a series of projections 44 that angle away from the force exerted by the geogrid. The geogrid is normally hooked by the projections 44 and extends back into the slope. It is noted that in embodiments that include a top split panel 12 the projections are generally attached to the second section 20 , which tend to pull the front of the block 10 back towards the slope.
[0062] Yet another embodiment of a block 10 of the present invention which includes a wall reinforcement device 38 is depicted in FIG. 4C . FIG. 4C depicts a top panel 12 that includes a front panel 20 having an elongated member 46 . In this embodiment the elongated member 46 extends the width of an edge of the second section 20 of the top panel 12 . The elongated member 46 may be a section of textured environment resistant material, such as a plastic rod, that may be integral with the second section 20 . The second section 20 in this embodiment may further include a ridge 48 positioned a distance from and running parallel with the elongated member 46 , which thereby forms a groove 50 sized to receive and retain a grid retention rod 52 . The ridge 48 may be a continuous structure of polymeric material or may be a series of pegs spaced apart from each other, but spanning the length of the second section 20 .
[0063] In operation, the wall reinforcement fastener 38 depicted in FIG. 4 functions by extending a section of geogrid fabric 54 over the first section 18 of a block 10 and under and around the rod 52 . Once around the rod 52 , the geogrid fabric 54 extends back towards the slope and the rod 52 is positioned in groove 50 . The wall reinforcement retention device 38 depicted in FIG. 4 generally holds the geogrid 54 in place by positioning the elongated member 46 , ridge 48 and rod 52 within a channel 56 positioned on a lower panel 14 of a block when the block is lowered onto the top panel 12 of a block below.
[0064] Finally, another embodiment of a wall reinforcement retention device 38 that may be utilized with blocks 10 of the present invention may be to integrate the geogrid fabric 54 with the block 10 . Integration of the geogrid 54 to the block 10 may be done by utilizing a fastener or means to fasten the geogrid fabric to the block or by molding the geogrid 54 directly into the block 10 . This may be done by utilizing any fastening means know in the art, such as adhesives, staples, solvent welding, clips, rivets and any other fastening means, which would retain the fabric 54 to the block 10 . FIG. 4D depicts an embodiment of the present invention wherein the geogrid 54 is integrated into the top panel 12 the block 10 . Alternatively, it is noted that the geogrid may be integrated into the bottom panel 14 or wall assembly 16 , such as the back wall panel.
[0065] The retaining wall block 10 of the present invention may further include one or more anchoring devices that interlock the blocks and rows of the constructed retaining walls utilizing such blocks 10 . FIG. 5A depicts one embodiment of the present invention wherein the anchoring devices include one or more insertable pegs 58 . The pegs 58 may be inserted into apertures 22 shaped similar to the pegs 58 or in a slightly oblong configuration to accommodate adjacent block fitting issues that may arise during construction of a wall. Alternatively, the insertable pegs 58 may also be received by a block 10 position below that includes a single aperture 22 that is in the shape of a trough 59 that extends across the width of the top panel 12 as depicted in FIG. 5B . In one embodiment of the present invention, the trough may be positioned between the first section 18 and second section 20 of the top panel 12 . In various embodiments the pegs 58 may be closed structures or, alternatively, open conduits that allow for the flow of fill material from one block to the blocks positioned below.
[0066] In FIG. 5A the insertable pegs 58 are positioned on the bottom panel 14 and are configured to be securely receivable in the apertures 22 of one or two top panels 12 of one or two adjacent retaining blocks 10 positioned below. The insertable pegs 58 can be made of any shape and size, which can be securely fit into the apertures 18 of the top panel 12 and optionally penetrate into the fill material of the block below. For example the pegs may be shaped as a cone or rod, wherein the bottom of the peg is pointed to better penetrate the fill material inserted in the block below. The insertable pegs 58 may also function to seal the interior of the below adjacent retaining block 10 from outside elements.
[0067] FIGS. 6 and 7 depict other types of peg configuration. FIG. 6 illustrates a bottom panel 14 of one embodiment of the present invention wherein the insertable pegs 58 are aperture inserts. Each insertable peg 58 of this embodiment includes a peg extension 60 which extends down from a sealing panel 62 . In operation, the peg extensions 60 are placed into an aperture 22 , which is position on the bottom panel 14 of a block. The aperture 22 may be oblong to accommodate lateral movement of the insertable peg 58 so that it may line up with a corresponding aperture on the top panel of a block positioned below. The sealing panel 62 will be generally larger than the aperture 22 positioned on the bottom panel 14 to properly seal the aperture 22 when the insertable pegs 58 adjoined to a block are locked into position on the wall. The insertable pegs 58 will be set into position upon entry into the aperture and fill material of the block below and with the weight of the fill material upon filling the block of which the insertable pegs are placed. The insertable pegs 56 may be solid in structure or may be an open conduit for the intermingling of fill material from one block to the next. Such intermingling of fill material may be beneficial in adding extra friction between blocks and thereby increase their connectivity.
[0068] In an alternative embodiment, wherein the insertable pegs 56 include an open conduit as depicted in FIG. 6A , the peg extensions 60 may comprise a plurality of protrusions 64 extending from the sealing panel 62 . The protrusions 64 may be pointed to better penetrate the fill material of the block positioned below and together may form the general shape of the aperture they project from.
[0069] In an alternate embodiment, as depicted in FIG. 7 , the insertable pegs 58 may slide within a mounting tray 66 positioned on the bottom panel 14 . The sealing panel 62 is generally sized to fit within the mounting tray 66 so that the panel 62 is retained within the upper tray edges 68 and slides freely in a lateral movement within the tray 66 . The lateral movement of the peg 58 will be available until the peg 58 is placed in an aperture 22 of a top panel 12 of a block positioned below.
[0070] In operation a block 10 is maneuvered so that the pegs 58 of one block 10 are inserted into the apertures 22 of one or more blocks. FIG. 8 illustrates a block 10 , which includes insertable pegs being lowered into the apertures 22 of two blocks 10 positioned below. This application is beneficial if the blocks of adjacent rows are staggered in positioning. See FIGS. 9A and 9B for an illustration of a staggered retaining wall. The interlocking of the blocks assists in vertical and horizontal connectivity of a constructed wall.
[0071] FIG. 9A depicts another embodiment of the present invention wherein a plurality of stabilizing rods 70 are extended through the apertures 22 of the blocks 10 to further interlock the blocks 10 and rows of block into position on the wall. Additionally, the stabilizing rods may further be utilized to retain geogrid fabric 54 that is positioned between the rows of block and extends back into the slope adjacent to the wall.
[0072] Another embodiment of the present invention is depicted in FIGS. 10-11 . The embodiment shown in FIG. 10 comprises a deterioration resistant retaining block 10 with the top panel removed, wherein the wall assembly 16 defines more than one chamber 26 within the retaining block 10 . The multiple chambers 26 are defined by interior partitions 28 . The interior partitions 72 may also be utilized to add additional support to the retaining block 10 to prevent any possible crushing of the block 10 . The interior partitions 72 may also act as wall panels if the block is cut to accommodate partial blocks for properly fitting a wall. FIG. 11 depicts one embodiment of the top panel 12 of a partitioned retaining block 10 . The interior partitions 72 are within the interior of the retaining block 10 and are depicted by dashed lines. The top panel 12 in this embodiment is permanently fixed to the wall assembly 16 and includes one or more apertures 18 or a trough (not shown) that may accommodate filling of each individual chamber 26 with appropriate fill material, such as sand, gravel, soil, cement or any other suitable material or may be utilized to receive pegs for anchoring the other blocks of a wall into position.
[0073] FIG. 12A depicts another possible embodiment of the top panel 12 , which is configured in a cover formation that may be adapted to securely fit over the retaining wall block 10 illustrated in FIG. 1 or 10 . The top panel 12 of this embodiment comprises a closed section 74 that includes overlapping panels 76 , which overlap securely over the outside walls of a wall assembly 16 , but does not include apertures. However, the top panel may also secure to the wall assembly 16 in other ways, such as locking tabs, twist locks, clamps, clips, adhesives or any other fastener. The top panel may further include optional top partitions 78 to fit over wall panels if a block 10 is cut to form partial blocks.
[0074] The top panel 12 may also be manufactured so that the overlapping panels 76 are sized to completely cover the wall assembly 16 and/or the front panel 80 of the block 10 . FIG. 12B depicts an embodiment of a block 10 wherein the top panel 12 includes overlapping panels 76 that extend over the wall assembly 16 of the block 10 . In various embodiments, the overlapping panels 76 or front face 82 may also include designs or textures that provide a rock or stone appearance. As in other embodiments the overlapping panels 76 and/or front face 82 may include any design or color that may be molded or blended into the polymeric material. The block 10 may further include a ridge 82 that extends around the base of the block 10 to receive the edges of the overlapping panels 76 of the top panel 12 after filling of the block 12 and closing with the top panel 12 .
[0075] An alternative embodiment of a block 10 of the present invention that includes overlapping panels is depicted in FIG. 12C . The embodiment in FIG. 12C includes a top panel 12 having an overlapping panel in the form of a front face 82 that extends substantially over the front of the block 10 and may include a design or texture, such as a rock or stone appearance. The front face 18 may also include an apron 91 that extends back from the front face 82 and is received and surrounds the front of the block 10 when the top panel is placed over the block 10 . The top panel 12 may further include a wrap around latching device 93 that extends around the back of the block 10 and hooks or secures the top panel 12 in position when the top block 10 is closed or sealed. The top panel 12 may further include overlapping tabs 89 that may extend from the side edges of the top panel and are received by recesses 87 positioned on the side panels of the block 10 . Furthermore, the production of such a block with an overlapping front face may allow for the block portion to be prepared from a lower grade material (e.g. recycled plastic) and/or without additives, such as color or UV light stabilizers and the top panel 12 with an overlapping front face to be made with such additives. However, it is noted that in various embodiments the entire block, including top panel and overlapping front face, may be made of recycled plastic.
[0076] In other embodiments of the present invention, the top panel 12 may optionally be hingedly secured to the retaining block 10 by any type of hinge device 86 , thereby providing a unitary configuration of the retaining wall block 10 . For example the hinge device 86 may be a living hinge wherein the hinge is a section of scored plastic that provides a folding point for the top panel 12 . However, it is noted that any type of hinge may be utilized. FIG. 13A depicts one embodiment of the present invention including a top panel 12 hingedly adjoined to a front panel of the retaining wall block 10 . It is noted that the top panel 12 may be hingedly attached from any wall panel 24 of the block including the back, sides or front. The hinging of the top panel 12 to the front or side panels of a block 10 may provide filling benefits by allowing greater ease in filling the blocks 10 during the backfilling of fill material behind the wall being constructed. It is also noted that in various embodiments the top panel 12 may be stationary or fixed to the block 10 and other panels of the block may be hingedly attached so that these panels may be opened to accommodate the filling of the block 10 . For example, the back panel or a side panel may be hingedly attached to the top or bottom panel so as to allow the back of the block or the side of the block to receive fill material before closing and placing into position.
[0077] In another embodiment of the present invention the block 10 may include one or more recesses 87 for receiving overlapping tabs 89 that fit over and within the recesses 87 . FIG. 13B depicts one embodiment of a block 10 that includes recesses 87 . The recesses 87 may be of any shape or size, but are generally of a depth so that the overlapping tabs 89 , when received to no expand the width of the upper portion of the block 10 . FIGS. 13C and 13D depict two embodiments of top panels 12 that include overlapping tabs 89 . FIG. 13C depicts a one piece top panel that may include a hinge 86 , such as a living hinge that is an integrated plastic hinge, and the overlapping tabs 89 . It is noted that in various embodiments the top panel 12 may be disengaged or separated from the block, but still include tabs 89 on any of the edges of the panel 12 for engaging the recesses of the block 10 . FIG. 13D includes a top panel 12 that includes a first section 18 and second section 20 . Each section 18 , 20 include hinge devices 86 and tabs 89 that hold the position of the split top panel 12 within the recesses. It is noted that the overlapping tabs 89 may provide additional structural support for a filled block by inhibiting the top portion of the block from bulging after filling with a fill material.
[0078] As previously mentioned, multiple chambers 26 allow for the retaining block 10 to be cut, either at installation or during manufacture, into various shapes and still maintain a chamber that can receive and retain fill materials. FIG. 14 depicts a section of the retaining block 10 as shown in FIG. 10 wherein the corners have been removed and the block 10 has been cut in half. However, a block may be configured to be cut into any size block (e.g. quarter block, half block, three quarter block . . . ). The ability to cut the retaining block 10 and still retain the same features is particularly useful in preparing ends and awkward segments of retaining walls. Dashed lines depicted in FIG. 12 illustrate one embodiment of alternate cover configurations to conform to the various shapes of a retaining block 10 or portions thereof.
[0079] In an alternate embodiment, a block 10 may be cut and sealed with an end cap 77 . The end cap 77 will generally include a sealing section 79 and a block hooking device 81 for securing the sealing section 79 to the block. In one embodiment of the present invention, as depicted in FIG. 14A , the wall hooking device 81 is in the form of a wall section. A wall section normally traverses around or partially around the perimeter of the sealing section 79 and either may extend over the top panel, bottom panel, front face and back panel of a block or may extend within the block and contact the interior of one or more of these panels. The end cap 77 , as depicted in FIG. 14A , depicts an end cap 77 that includes a wall section that extends within the interior of the block 10 and further includes a hooking crest 85 that may engage one or more hook receiving devices 83 positioned within a block. The hooking crest 85 may be a crest that extends around the entire interior edge of the end cap 77 or may be a plurality of tabs positioned around the periphery of the interior edge of the end cap 77 . FIG. 14A depicts the embodiment with a plurality of tabs as the hooking crest 85 . An example of a block 10 that includes one or more hook receiving devices 83 is depicted in FIG. 14B , wherein a series of ridges are present within the interior of the block 10 .
[0080] In operation utilizing one embodiment of the present invention, a block 10 may be cut in a straight line alone one of the hook receiving devices 83 , such as a ridge. Next the cap 77 is inserted into the side of the cut end of the block 10 and the hooking device 81 , such as a wall section with a crest 85 , is allowed to hook a hook receiving device 83 , such as a ridge, adjacent to the cut line. Caps 77 may be manufactured to properly fit either side of the block depending upon which side requires cutting. It is noted that the cap 77 may include other alternative hooking devices 83 , such as recesses and tabs, or hook and piles, to secure the sealing section 79 into a secure position and maintain the fill material within the chamber 26 .
[0081] An additional embodiment of the present invention is depicted in FIGS. 15 and 16 . FIG. 15 illustrates a top view of a multi-unit retaining wall block 88 wherein multiple units 90 are incorporated into a single block 88 . A single multi-unit block 88 provides the appearance of multiple retaining blocks present in a single structure. The top panel 12 may be a single sheet or multiple sheets of material which may be adapted to cover each unit 90 and optionally may include apertures 22 . The interior of the retaining block 88 of this embodiment includes one or more interior partitions 72 . Removable tabs 92 may be positioned between the partitions to properly space the blocks and hold the individual units 90 together. The tabs 92 may be a simple piece of plastic or other polymeric material that may be removed by cutting or breaking to free the individual units 90 or maneuvering them if a rounded wall is desired.
[0082] FIG. 16 depicts the front view of the multi-unit retaining block 88 , which has the appearance of multiple separate units or blocks 90 . These multiple separate units 90 provide the appearance similar to the partial assembly of a retaining wall comprising a plurality of individual blocks, such as depicted in the walls of FIGS. 9A and 9B . The multi-unit retaining block 88 may include a top panel 12 that is a unitary structure or may include multiple covers, such as a multi-unit block 88 including multiple separate top panels similar to the top panel depicted in FIG. 12 or a hinged panels similar to that depicted in FIG. 13 .
[0083] FIG. 17 depicts another embodiment of a multi-unit retaining wall block 88 , wherein a few of the tabs 92 in the back have been collapsed inward on pivot points on the tabs and the multiunit block has been rounded. It is noted that in other embodiments the tabs may be removed by cutting to also perform the rounding function. In this embodiment of the present invention, tabs 92 may be positioned between each individual unit 90 on the front, middle and/or back of the multi-unit block 88 . If a curved wall is desired, the tabs 92 may be disengaged, collapsed or extended, thereby allowing one or more multi-unit blocks 88 to be maneuvered into a curved position. It is noted that the tabs 92 may include one or more hinges to allow for the rotation of each unit 90 while maintaining their connection or the hinges may be disengaged to allow for separation of the units 90 .
[0084] FIG. 18 depicts an additional embodiment of the present invention, similar to hook and pile attachments, wherein the retaining wall block 10 includes an interlocking feature that comprises a clip 94 and optional pocket 96 . In such an embodiment one or more clips 94 may extend from one side of a retaining wall block 10 over another side of an adjacent retaining wall block into a trough or one or more corresponding pockets 96 . Such interlocking mechanisms provides for a overall secure retaining wall structure by reducing the amount of lateral movement that may occur with unsecured stacking of individual blocks.
[0085] In various embodiments of the present invention the blocks may be nestable for stacking. Various embodiments of the present invention, such as those depicted in FIG. 19 , also provide for ease in transport and storage of large numbers of these blocks due to stackable features. An additional example of a stackable retaining block 10 may be similar to that as shown in FIG. 1 , wherein the top panel 12 is removable or hinged and allows for the retaining block 10 to be inserted within the chamber 26 of another block 10 . Generally the slight sloping of the wall assembly allows for the nesting of such blocks. Angles of the wall assembly may vary, but generally include a 1° to 15° angle, preferably 2° to 5°. The top panel 12 for such a retaining block 10 may include a cover similar to any of the top panels 12 shown in the Figures herein.
[0086] As previously mentioned, the present invention may be manufactured from a deterioration resistant, substantially rigid composite or polymeric material including, but not limited to, plastic, a rubber composition, fiberglass, or any other similar material or a combination thereof. Preferable materials are light-weight and slightly flexible. In various embodiments of the present invention plastics, such as high density or low density polyethylene, polypropylene or plastic polymer blends may be utilized. Furthermore, plastics that include additives such as wood fibers or clay may be used in the process to form the blocks of the present invention. Generally, the embodiments of the present invention may comprise any type of material that would have the similar characteristics to plastic, vinyl, silicone, fiberglass, rubber or a combination of these materials. However, it is noted that the material utilized in the present invention should be rigid enough to hold its form upon addition of filling material and also when placed in contact with other objects. Another preferable material may be comprised of a material similar to that utilized in the production of some types of garbage cans or the utilization of recycled rubber from objects such as tires. Such materials would be capable of holding rigidity and still offer flexibility when placed in contact with other objects, such as other retaining wall blocks or ice. Also, such materials have the ability to regain its original form when the object or material has been removed.
[0087] Embodiments of the present invention may also vary in appearance. Since embodiments of the present invention may be manufactured by a process such as injection molding, the molds may include any type of design, texture or shape. For example, the front face and top panel of blocks may be textured and colored to take on the appearance of stone or rock formations. Furthermore, the front panels of the retaining wall block 10 could be molded in almost any type of configuration. Examples of designs are depicted in FIGS. 8 and 9A . In one embodiment, multiple retaining wall blocks could be molded to include designs that, when positioned on a retaining wall, would complete a larger single design, such as the spelling of a company or school name in large letters or the completion of a large image. Also, since the present invention may be manufactured from a number of different products, such as plastic, a rubber composition or fiberglass, the retaining wall block may comprise any color or a multitude of colors. For example, a retaining wall installed in a beach setting may be manufactured of a plastic or rubber product and be colored in so that organic matter wash up on it would not show up as readily.
[0088] As previously suggested the environment resistant retaining wall block is utilized in the construction of any type of wall or border. In application, a foundation is first created in the area that the wall or border is to be constructed. The foundation preferably is flat and or level, firmly packed to reduce settling and can accommodate one or more retaining blocks 10 . Once a foundation is completed, a first row is laid by filling each individual retaining block 10 with a fill material and placing each individual or multi-unit block, side by side until the row is completed. It is noted that individual rows or partial rows of blocks may be placed into position and then filled to create ease in wall construction. Such action would allow for filling of the block during the backfilling behind the block. The filling of the retaining wall block gives it the added weight that it needs to retain its structure and hold it in place. A funneling device may be utilized, which fits securely into the openings or apertures of the retaining wall block to guide fill into the chamber of the block. The first row may be straight or rounded. An example of a rounded first row is depicted in FIG. 17 . Upon completion of the first row, additional rows are constructed by performing the same filling process and placing the retaining wall block 10 in the proper position until a continuous retaining wall is completed. Generally, a continuous retaining wall may include stacked rows wherein individual retaining blocks are placed adjacently to one another thereby eliminating or minimizing cracks or gaps in the wall. Retaining wall blocks 10 may be positioned directly over other retaining wall blocks 10 in lower rows or may be staggered. It is noted that each retaining wall block placed in the retaining wall may be configured to retain and seal the contents of the fill material. This is accomplished by either one or more plugs or covers that seals each open aperture or by enclosing or covering an open aperture with a portion of an adjacent block. Furthermore, the retaining wall blocks 10 of the upper rows may overlap the back of retaining wall blocks 10 of lower rows if a retaining flange 24 is included on the block or in some embodiments when the blocks include anchoring devices. In the alternative or additionally, each individual retaining block 10 may be locked into position with adjacent blocks if pegs 24 and apertures 18 or clips 94 are present on the retaining block 10 .
[0089] Upon completion of the top row of the retaining wall, a cover or capping block 98 may be placed over the top row to close the apertures 18 of the top panels 12 or to provide a finishing border to the top of the retaining wall. An example of a capping block 98 , as depicted in FIG. 20 , may be polygonal in shape and include textured faces on both the front panels 80 and back panels 100 of the block 98 . The capping blocks 98 may further include pegs (not shown), similar to those depicted in the previous block embodiments, that may be utilized to secure the capping block to the blocks positioned below. Alternatively, the capping blocks may be secured to the blocks below by any means known in the art, such as clips, tacks, adhesives or the like. The capping blocks may be filled with a fill material, similar to the other embodiments of the present invention, or may be a simple thinner block that may include a plurality of reinforcing partitions 72 as disclosed in FIG. 20 .
[0090] Embodiments of the present invention may also be used in conjunction with regular dry cement process blocks, bricks or stones, such as those produced by Keystone® or Anchor Wall Systems. A retaining wall constructed in water or along a waterfront property may utilize the retaining wall block of the present invention at water level and below and then the regular keystone or retaining wall materials can be used on top of the retaining wall block of the present invention. The utilization of the retaining wall block of the present invention would be easy to match colors with the conventional retaining wall building materials because the materials utilized to manufacture the present invention can be colored and designed to match virtually any type of retaining wall construction material.
[0091] Furthermore, the retaining wall block may be manufactured in a multitude of different sizes, shapes and configurations. For example, an embankment or steep shoreline could support a retaining wall configured in a step like arrangement or design. Such a structure, may be utilized as a retaining wall and/or a stairway down to the beach or to the water.
[0092] While the invention has been illustrated and described in detail in the drawings and foregoing description, such an illustration and description is to be considered as exemplary and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
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The present invention relates to a retaining wall block that is resistant to damage and wear caused by the environment it is placed into. The deterioration resistant block is generally a hollowed frame or shell of a deterioration resistant material that is lightweight and is configured to accept and retain any type of filling material. The filling material provides weight and stability to the retaining wall block and also provides weight, stability and security to a retaining wall constructed of such blocks.
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BACKGROUND
[0001] The invention relates to a vehicle coupling comprising a coupling body and at least one structural element arranged thereon, and a method for manufacturing a vehicle coupling.
[0002] The coupling body and the components interacting therewith are usually manufactured in a casting process from cast steel or nodular cast iron or are welded together from sheet metal parts. The resulting robust construction is necessary for the high operational forces to be expected so as to avoid deformations and to ensure a maximum wear protection. However, said previously used constructions have the disadvantage that the component weights and the operating expenses for processing, in particular performing the welding on sheet metal parts, are high.
[0003] Thus, the invention was based on the object to provide a vehicle coupling that is optimally dimensioned for the reduction of weight and cost in particular areas with respect to the expected mechanical load.
[0004] Another part of the object was to develop a corresponding manufacturing method for vehicle couplings.
SUMMARY
[0005] The object is solved according to the invention with a vehicle coupling for which the structural element is force fit to the coupling body by means of a bulk plastic material. The composite coupling produced in this manner has the advantage that the manufacturing costs are considerably reduced due to the minimal efforts for joining the individual parts. Moreover, the vehicle coupling according to the invention can be formed with complex geometries which otherwise can be implemented only with considerable additional expenses. This includes, for example, attaching holders for fastening additional components on the vehicle coupling.
[0006] Another advantage of the vehicle coupling according to the invention is the possibility to work, in mechanically low loaded areas, with thinner metal sheets and wall thicknesses as this is the case in the traditional construction. Known manufacturing methods need certain minimum wall thicknesses for welding or casting-related reasons, even if only low loads are to be expected.
[0007] Moreover, the vehicle coupling according to the invention has advantages in case of high dynamic loads, in particular in comparison to welding constructions in which the weld seams form a weak spot.
[0008] Preferably, the coupling body comprises a coupling plate of a fifth wheel coupling. As an alternative, the coupling body can be formed from a coupling jaw of a trailer coupling or bolt coupling.
[0009] It was found to be advantageous if the coupling plate or coupling jaw is made of metal. In particular the upper side of the coupling plate of a fifth wheel coupling should have a metallic upper side. This is of advantage because of the high mechanical load of the upper side but also because of the visual appearance.
[0010] The structural element can preferably be formed from at least one reinforcement rib and/or holder and/or bearing point. A reinforcement rib is to be understood as a wall or stiffening structure for increasing the bending strength which is arranged in the assembled state of the fifth wheel coupling underneath the coupling plate. Holders on a vehicle coupling can be, for example, threaded insert parts. On a fifth wheel coupling, the bearing points are arranged on opposite lateral positions on bearing blocks arranged below the coupling plate for supporting the coupling plate. In particular reinforcement ribs and bearing points lie in the force flow of the operational forces.
[0011] Advantageously, a plurality of structural elements are provided on the vehicle coupling which are interconnected by means of a force-fit bulk plastic material. Thereby, a stabilizing framework structure can be obtained.
[0012] According to a particularly advantageous embodiment, the structural element is made of metal and/or carbon fiber and/or fiber glass. In consideration of the load expected in the respective area, the vehicle coupling according to the invention allows the use of different materials for the structural elements which lie within the force flow. By using carbon fiber elements and/or fiber glass elements, particularly significant reductions of the weight of the vehicle coupling can be achieved.
[0013] Particularly high strengths, in particular of the structural element, can be achieved with so-called metal foams. The metal foam is made from a foaming agent and a metal powder added thereto, wherein the metal powder consists in most cases of aluminum or steel. After foaming agent and metal powder are brought together and mixed, a first forming process and a subsequent foaming takes place. The foam structure results in very low volume density while the strength of the metal foam is only insignificantly reduced.
[0014] Advantageously, the structural element is in contact with the bulk plastic material with at least one side. This is achieved, for example, in that the structural element is completely or partially molded-in in the bulk plastic material or is foam-encapsulated by the same. A partially molded-in or foam-encapsulated structural element is visible with at least one side also in the assembled state. This has the advantage that a machinable and robust surface of the structural element is provided. Here, in particular in the area of the reinforcement ribs, a sandwich-like structure consisting of coupling element, bulk plastic material and structural element is obtained. A structural element that is completely molded-in in the bulk plastic material or is completely encapsulated in foam is not accessible from outside and provides a particularly effective corrosion protection.
[0015] Besides the structural element, also the vehicle coupling can be completely enclosed by the bulk plastic material. Provided that the vehicle coupling is a fifth wheel coupling, there is the possibility to manufacture a coupling plate which, for example at the contact points to the semitrailer or the bearing blocks, needs less or no lubricant.
[0016] A particularly high strength can be achieved if the bulk plastic material is fiber- reinforced.
[0017] Suitable as materials for the bulk plastic material are thermoplastics and thermosetting plastics. A thermoplastic resin deforms by heat and maintains its shape when cooling down. The best known thermoplastics are polypropylene, polyethylene, polyester, polyvinylchloride, and polyamide. Thermosetting plastics, also called duromers, are plastics which can not be deformed any more after their curing. Thermosetting plastics are hard, glass-like polymeric materials which are three-dimensionally cross-linked via chemical primary valence bonds. The cross-linking takes place during mixing of precursors with branch points and is either chemically activated at room temperature by means of catalysts or thermally activated at high temperatures.
[0018] In particular a plastic foam can be used as bulk plastic material. Also, the use of a metal foam as bulk plastic material is particularly suitable. Since the foaming agent of the metal foam comprises a plastic material, the metal foam is understood in a broader sense as bulk plastic material.
[0019] The object is also solved by a manufacturing method in which the structural element is aligned on the coupling body according to its subsequent arrangement and is force-fit to the same by means of a bulk plastic material. Here, it was found to be advantageous to put the coupling body and the structural element in a molding tool. After curing of the bulk plastic material, the vehicle coupling formed from coupling body and structural element can be removed from the molding tool.
[0020] Advantageously, the coupling body comprises a coupling plate, onto which the structural elements are placed.
[0021] Preferably, the coupling plate according to the invention is placed on its side provided as upper side in the assembled state, and the at least one structural element is placed on its side provided as lower side in the assembled state. In this alignment, the structural elements can be fixed in their designated position in a particularly comfortable manner.
[0022] In a particularly advantageous method step, the structural element is completely or partially molded-in by the bulk plastic material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] For a better understanding, the invention is illustrated hereinafter by means of a total of seven figures. In the figures:
[0024] FIG. 1 shows a top view of a portion of the horizontally cut coupling plate according to a first embodiment;
[0025] FIG. 2 shows a cross-section along the sectional plane A-A in FIG. 1 ;
[0026] FIG. 3 shows a cross-section along the sectional plane B-B in FIG. 1 ;
[0027] FIG. 4 shows a top view on a portion of a horizontally cut coupling plate according to a second embodiment;
[0028] FIG. 5 shows a cross-section along the sectional plane A-A in FIG. 4 ;
[0029] FIG. 6 shows a cross-section along the sectional plane B-B in FIG. 4 and
[0030] FIG. 7 shows a cross-section through a coupling plate according to a third embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] FIG. 1 shows a top view on a horizontally cut coupling plate 4 as coupling body 1 of a fifth wheel coupling according to a first embodiment. On its rear side 11 , the coupling plate 4 has an insertion opening 9 into which a non-shown king pin of a semitrailer can be inserted in a usual manner in the fifth wheel coupling. The insertion opening 9 is bordered on both sides by a coupling horn 10 , wherein the illustration of FIG. 1 shows only the coupling horn 10 on the right side as viewed in driving direction.
[0032] In driving operation, the lower side of the semitrailer, which is not shown, is supported on the bearing area 12 (see FIG. 2 ) of the coupling plate 4 . Thus, in this bearing area 12 , considerable forces are transmitted into the coupling plate 4 . To avoid dimensioning the entire coupling plate 4 with a large material thickness and a correspondingly high weight, a structural element 2 in the form of a reinforcement rib 5 is arranged on the lower side 8 (see FIG. 2 ) of the coupling plate 4 .
[0033] The reinforcement rib 5 comprises a substantially horizontally extending base plate 14 on which vertically positioned wall sections 15 a, 15 b are formed. According to the first embodiment illustrated in the FIGS. 1 to 3 , the reinforcement rib 5 is a forging or metal stamping part with comparatively sharp-edged transitions between the base plate 14 and the wall sections 15 a, 15 b.
[0034] As is particularly well illustrated in FIG. 2 , the reinforcement rib 5 is glued by means of a bulk plastic material 3 underneath the coupling plate 4 . Here, the coupling plate 4 is continuously filled up to its edge region 16 with the bulk plastic material 3 . Also arranged between the coupling plate 4 and the reinforcement rib 5 is a sheet-like spacer horizon 13 made of the bulk plastic material 3 . Furthermore, the shown first embodiment has a reinforcement rib 5 which is completely surrounded by the bulk plastic material 3 .
[0035] In addition, the structural elements 2 comprise holders 6 which are stationarily fixed below the coupling plate 4 . The holder 6 illustrated in FIG. 2 is a threaded insert part which is also inserted in the bulk plastic material 3 and is partially surrounded by the same.
[0036] FIG. 3 shows a cross-section through the closure area of the fifth wheel coupling, wherein the cut line in the assembled state of the coupling plate 4 corresponds to the longitudinal axis of the vehicle. In this area, between the upper side 7 of the coupling plate 4 and the reinforcement rib 5 , a free installation space is provided which serves for inserting or fixing the king pin. Also in this area, the reinforcement rib 5 is completely surrounded by the bulk plastic material 3 .
[0037] FIG. 4 illustrates an alternative embodiment according to the invention in which the reinforcement rib 5 is manufactured as a pressed sheet metal part. Pressed sheet metal parts have comparatively round bending lines as is particularly well illustrated in the cross-sections of the FIGS. 5 and 6 . The pressed sheet metal part used as reinforcement rib 5 is also completely glued into the bulk plastic material 3 .
[0038] FIG. 7 shows a third embodiment in which the profiled reinforcement rib 5 is glued to the lower side 8 of the coupling plate 4 only via the spacer horizon 13 . Provided that the reinforcement rib 5 is made of metal, conventional metal working methods can be used in further manufacturing steps on the lower side of the reinforcement rib 5 .
REFERENCE NUMBER LIST
[0000]
1 Coupling body
2 Structural element
3 Bulk plastic material
4 Coupling plate
5 Reinforcement rib
6 Holder
7 Upper side of coupling plate
8 Lower side of coupling plate
9 Insertion opening
10 Coupling horn
11 Rear side
12 Bearing area
13 Spacer horizon
14 Base plate
15 a,b Wall section
16 Edge region of coupling plate
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A vehicle coupling, and a method for the manufacture thereof, having a coupling body ( 1 ) and at least one structural element ( 2 ) placed thereon wherein the structural element ( 2 ) is force fit to the coupling body ( 1 ) using a bulk plastic material ( 3 ).
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a hydraulic control system for an internal combustion engine, which has two hydraulic operating mechanisms operated independently by oil pressure of a common oil pressure source. The present invention further relates to a hydraulic control system for an internal combustion engine, which has two variable valve timing control mechanisms capable of varying lift characteristics of at least one of an intake valve and an exhaust valve.
[0002] In the field of internal combustion engines, it is a common practice to actuate various kinds of hydraulic operating mechanisms by using an oil pump for circulation of lubrication oil as an oil pressure source. Examples of such hydraulic operating mechanism are a variable valve timing control mechanism for varying the opening and closing timings and the lift of the intake and exhaust valves in accordance with the operating condition of the engine and a variable compression ratio control mechanism for varying the piston stroke of each cylinder and thereby varying the compression ratio in accordance with the operation condition of the engine.
[0003] An example of a hydraulic variable valve timing control mechanism is disclosed in Japanese Patent Provisional Publication No. 5-248217. This variable valve timing control mechanism is capable of varying the opening and closing timings of the intake and exhaust valves in two steps by switching from one of a low-speed rocker arm and a high-speed rocker arm to another. Other variable valve timing control mechanisms are a variable phase control mechanism for varying the operation angle phase (i.e., maxim lift phase) of the intake and exhaust valves, an operation angle varying mechanism for varying the operation angles and valve lifts of the intake and exhaust valves and a valve stop mechanism for temporarily stopping the intake and exhaust valves of some of the cylinders.
SUMMARY OF THE INVENTION
[0004] In this connection, in case two hydraulic operating mechanisms which are operated independently by oil pressure of a common oil pressure source e used in an internal combustion engine, there is a possibility of causing the following problems. Namely, In case the operating conditions of both of the hydraulic operating mechanisms are changed simultaneously, particularly at a low-speed engine operating condition where the oil pressure produced by the oil pump is low, there is a possibility that the hydraulic operating mechanisms become poor in responsiveness due to a lack of the oil pressure supplied thereto. To prevent such deterioration of the responsiveness, it is considered to use an oil pump, accumulator or the like for the hydraulic operating mechanisms' exclusive use. However, in this instance, a hydraulic circuit of the hydraulic control system becomes complicated in structure, thus causing a possibility of increasing the weight and the cost.
[0005] Particularly, in case the two hydraulic operating mechanisms are variable valve timing control mechanisms for varying the lift characteristics of the intake and exhaust valves, it is highly necessitated to change the operating conditions of the variable valve timing control mechanisms at the same timing so as to attain the required lifts which vary largely in accordance with the operating conditions of the engine at idling or at full-throttle operation.
[0006] For example, in case a variable phase control mechanism for varying the operation angle phase of an intake valve and a valve stop mechanism for temporarily stopping the intake and exhaust valves of some of the cylinders are used, it is desirable, when the valve stop mechanism is operated to stop the intake and exhaust valves of some of the cylinders, to advance the operation angle phase of the intake valve by the variable phase control mechanism so that a predetermined torque can be attained by the remaining cylinders. In this instance, the delay of the responsiveness of the valve stop mechanism becomes a particularly large problem. Namely, in the cylinders where the intake and exhaust valves are stopped, it is necessitated to inhibit injection of fuel. If there is a difference between the period during which the intake and exhaust valves are actually stopped and the period during which injection of fuel is actually inhibited, it is possible that fuel is injected during the time of the valves being stopped. This is particularly not desirable.
[0007] It is accordingly an object of the present invention to provide a hydraulic control system for an internal combustion engine, which has two hydraulic operating mechanisms operated independently by oil pressure of a common oil pressure source and which is simple in structure and has an improved responsiveness.
[0008] To accomplish the above object, there is provided according to an aspect of the present invention a hydraulic control system for an internal combustion engine comprising a first hydraulic operating mechanism, a second hydraulic operating mechanism, the first hydraulic operating mechanism and the second hydraulic operating mechanism being operated independently by oil pressure of a common oil pressure source, and a circulation line that supplies pressure oil discharged from the first hydraulic operating mechanism to the second hydraulic operating mechanism.
[0009] According to another aspect of the present invention, there is provided a hydraulic control system for an internal combustion engine comprising an oil pressure source, an oil sump, a first hydraulic operating mechanism, a second hydraulic operating mechanism, a first hydraulic control valve for selectively communicating the first hydraulic operating mechanism with one of the oil pressure source and the oil sump thereby controlling an operation of the first hydraulic operating mechanism, a second hydraulic control valve for selectively communicating the second hydraulic operating mechanism with one of the oil pressure source and the oil sump, a control line fluidly connecting between the second hydraulic control valve and the second hydraulic operating mechanism for conducting pressure oil supplied to and discharged from the second hydraulic operating mechanism, and a circulation line connecting between the first hydraulic control valve and the control line for supplying pressure oil discharged from the first hydraulic operating mechanism to the second hydraulic operating mechanism.
[0010] According to a further aspect of the present invention, there is provided a hydraulic control system for an internal combustion engine comprising a phase control mechanism for varying a phase of an intake valve, a valve stop mechanism for temporarily stopping intake and exhaust valves of some of cylinders, the phase control mechanism and the valve stop mechanism being operated by oil pressure of a common oil pressure source, and means for supplying pressure oil discharged from the phase control mechanism to the valve stop mechanism in addition to pressure oil supplied from the oil pressure source to the valve stop mechanism when the phase of the intake valve is advanced by the phase control mechanism and the intake and exhaust valves of some of the cylinders are stopped by the valve stop mechanism.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a hydraulic control system for an internal combustion engine according to an embodiment of the present invention;
[0012] [0012]FIGS. 2A to 2 C are schematic views for illustrating operations of a variable phase control mechanism and a hydraulic control valve for phase control, which are used in the hydraulic control system of FIG. 1;
[0013] [0013]FIG. 3 is a perspective view of a valve stop mechanism used in the hydraulic control system of FIG. 1;
[0014] [0014]FIGS. 4A and 4B are schematic views for illustrating operations of a hydraulic control valve for valve stop, used in the hydraulic control system of FIG. 1; and
[0015] [0015]FIGS. 5A and 5B are graphs for showing an advanced valve timing operation range and a part cylinder operation range, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] Referring first to FIG. 1, a hydraulic control system for an internal combustion engine includes first hydraulic operating mechanism 12 and second hydraulic operating mechanism 14 that are fluidly connected to oil pump 10 serving as a anon oil pressure source. In this embodiment, hydraulic operating mechanism 12 and 14 are embodied in valuable valve timing control mechanisms capable of varying lift characteristics of at least one of an intake valve and an exhaust valve of each cylinder. More specifically, hydraulic operating mechanisms 12 and 14 are embodied in a variable phase control mechanism for continuously varying the phase of an intake valve and a valve stop mechanism for temporarily stopping the intake and exhaust valves of some (e.g., a half) of the cylinders, respectively.
[0017] Further, the hydraulic control system includes hydraulic control valve 16 for phase control, that controls oil pressure supplied from oil pump 10 to variable phase control mechanism 12 , and hydraulic control valve 18 for valve stop, that controls oil pressure supplied from oil pump 10 to valve stop mechanism 14 .
[0018] Variable phase control mechanism 12 is of the type having been already proposed and described briefly with reference to FIGS. 2A to 2 C. Variable phase control mechanism 12 includes outer circumferential side gear potion 22 rotatable together with cam sprocket 21 which is in turn rotatable in timed relation with a crank shaft (not shown), inner circumferential side gear portion 24 disposed concentrically with and inside of cam sprocket 21 and rotatable together with intake cam shaft 23 , annular piston 25 meshed with the inner and outer circumferential surfaces of outer circumferential side gear portion 22 and inner circumferential side gear portion 24 by means of splines, and return spring 26 for urging piston 25 toward the retard side.
[0019] The opposite ends of piston 25 are associated with retard side oil pressure chamber 27 and advance side oil pressure chamber 28 , respectively. By axial movement of piston 25 in response to oil pressures in oil pressure chambers 27 and 28 , the phase of intake camshaft 23 relative to cam sprocket 21 is varied thereby varying the phase of the intake valve continuously.
[0020] Details of such a phase control mechanism are disclosed in Japanese Patent Provisional Publication Nos. 2000-073797, 2000-145487 and 2000-234533.
[0021] Valve stop mechanism 14 is of the type having been already proposed and described briefly with reference to FIG. 3. When the oil pressure in valve stop oil pressure chamber 31 is low, coupling 33 is urged by the bias of a spring (not shown) disposed inside thereof so as to protrude into a position where it contacts auxiliary rocker arm 36 a having roller bearing 34 . This causes rotational power to be transmitted to the intake and exhaust valves by way of auxiliary rocker arm 36 a , coupling 33 and rocker arm 36 thereby causing all the cylinders to operate. On the other hand, when a predetermined oil pressure is supplied to valve stop oil pressure chamber 31 , piston 38 pushes coupling 33 against the bias of the spring disposed inside coupling 33 and causes coupling 33 to move apart from auxiliary rocker arm 36 a . This shuts off transmission of power from auxiliary rocker arm 36 a to coupling 33 thereby performing a part cylinder operation where the intake and exhaust valves of some of the cylinders are stopped. Details of such a valve stop mechanism are disclosed in Pages 56 to 58 of Auto Motor and Sport (German car magazine) No. 15, published on Jul. 14, 1999.
[0022] Referring to FIGS. 1 to 4 A and 4 B, a hydraulic circuit of the hydraulic control system will be described. The hydraulic circuit includes first supply line 41 for supplying oil pressure from oil pumps 10 to hydraulic control valve 16 for phase control, second supply line 42 for supplying oil pressure fan oil pump 10 to hydraulic control valve 18 for valve stop, retard side control line 43 connecting between control valve 16 and retard side oil pressure chamber 27 , advance side control line 44 connecting between control valve 16 and advance side oil pressure fiber 28 , valve stop control line 45 connecting between control valve 18 and valve stop oil pressure chamber 45 , retard side drain line 46 for conducting pressure oil discharged from control valve 16 to oil sump or oil pan 11 , and drain line 47 for valve stop for conducting pressure oil discharged from control valve 18 to oil pan 11 .
[0023] In the embodiment, circulation line 48 is provided which is fluidly connected at one end to retard side oil pressure chamber 27 of phase control mechanism 12 and at another end to valve stop oil pressure chamber 31 of valve stop mechanism 14 so as to supply pressure oil discharged from retard side oil pressure chamber 27 to valve stop oil pressure chamber 31 . More specifically, circulation line 48 is connected at one end to control valve 16 so as to communicate with retard side oil pressure chamber 27 of phase control mechanism 12 by way of retard side control line 43 and at another end (downstream side) to valve stop control line 45 so as to communicate therethrough with valve stop oil pressure chamber 31 of valve stop mean 14 . Namely, circulation line 48 is constructed so that it can supply pressure oil discharged from retard side oil pressure chamber 27 not through control valve 18 but directly to valve stop oil pressure chamber 31 .
[0024] In circulation line 48 is disposed check valve 49 for preventing reverse flow of pressure oil from valve stop mechanism 14 to phase control mechanism 12 . Further, control valve 51 is disposed in advance side drain line 50 branching off from circulation line 48 at a location upstream of check valve 49 (i.e., on phase control mechanism 12 side of check valve 49 ) and extending up to oil pan 11 . The valve opening pressure of check valve 49 is set at a value lower than that of control valve 51 . For example, the valve opening pressure of check valve 49 is set at about 0.1 kgf/cm 2 and the valve opening pressure of control valve 51 is set at about 0.3 kgf/cm 2 .
[0025] The operation of the hydraulic control system will now be described.
[0026] Phase control mechanism 12 supplies a duty signal to a solenoid (not show) for driving spool 16 a of control valve 16 thereby feedback controlling the operation angle phase of the intake valve corresponding to the position of piston 25 .
[0027] More specifically, upon retard, i.e., when the operation angle phase of the intake valve is retarded, spool 16 a of phase control valve 16 is placed in the position shown in FIG. 2A. This causes the oil pressure from oil pump 10 to be supplied to retard side oil pressure chamber 27 by way of first supply line 41 and retard side control line 43 , while causing pressure oil in advance side oil pressure chamber 28 to be discharged through retard side drain line 46 into oil pan 11 . As a result, piston 25 is pushed toward the retard side (i.e., to the left-hand side in FIG. 2A). In the meantime, in FIG. 2A are shown the lift characteristics of the intake and exhaust valves that are retarded maximumly.
[0028] Upon advance. i.e., when the operation angle phase of the intake valve is advanced, spool 16 a is placed in the position shown in FIG. 2B. This causes oil pressure to be supplied to advance side oil pressure chamber 28 by way of first supply line 41 and advance side control line 44 , while causing pressure oil in retard side oil pressure chamber 27 to be discharged through retard side control line 43 and circulation line 48 . As a result, piston 25 is pushed to the advance side (i.e., to the right-hand side in FIG. 2B) . In the meantime, in FIG. 2B are shown the lift characteristics of the intake and exhaust valve that are advanced maximumly.
[0029] When the operation angle phase of the intake valve is to be held at any given phase, spool 16 a is placed in the position shown in FIG. 2C to close both of the ports connected to retard side control line 43 and advance side control line 44 . By this, the oil pressure in both oil pressure chambers 27 and 28 is confined therewithin, thus allowing piston 25 to be held at the present position, i.e., making it possible to hold piston 25 at any given position.
[0030] Valve stop mechanism 14 performs switching between full cylinder operation with all cylinders in operation and part cylinder operation with some of the cylinders kept out of operation, by switching the positions of spool 18 a of control valve 18 according to the operating condition of the engine as shown in FIGS. 4A and 4B. Specifically, at the time of full cylinder operation. spool 18 a of control valve 18 is placed at the position shown in FIG. 4A. This causes pressure oil in valve stop oil pressure chamber 31 to be discharged through valve stop control line 45 and valve stop drain line 47 into oil pan 11 . On the other hand, at the time of port cylinder operation, spool 18 a is placed at the position shown in FIG. 4B thereby causing oil pressure of oil pump 10 to be supplied through second supply line 42 and valve stop control line 45 to valve stop oil pressure chamber 31 .
[0031] In case oil pressure is supplied to valve stop mechanism 14 to start part cylinder operation at the time of advance, i.e., under the condition where pressure oil is discharged from retard side oil pressure chamber 27 into circulation line 48 , pressure oil is supplied through circulation line 48 to valve stop oil pressure chamber 31 rapidly. Namely, in addition to pressure oil supplied from oil pump 10 to valve stop oil pressure chamber 31 by way of second supply line 42 , control valve 18 and valve stop control line 45 , pressure oil is supplied from retard side oil pressure chamber 27 to valve stop oil pressure chamber 31 by way of circulation line 48 . Accordingly, retard side oil pressure chamber 27 functions as a kind of accumulator, so that it becomes possible to improve the responsiveness of valve stop mechanism 14 without using an additional accumulator or the like. As a result, it becomes possible to make longer the time of part cylinder operation and therefore it becomes possible to further improve the fuel consumption.
[0032] In other words, if the responsiveness of valve stop mechanism 14 is lowered, fuel will possibly be injected into a cylinder whose valves are stopped and therefore will possibly deteriorate the exhaust efficiency. However, since valve stop mechanism 14 starts part cylinder operation with an improved responsiveness, such a deterioration of the exhaust efficiency can be effectively suppressed.
[0033] Particularly, at low-speed engine operation, the oil pressure supplied by oil pump 10 is low so that the responsiveness of valve stop mechanism 14 tends to be lowered. However, according to the present invention, additional pressure oil is supplied from retard side oil pressure chamber 27 thereby enabling valve stop mechanism 14 to attain a good responsiveness even in an operation range where the oil pressure supplied to valve stop mechanism 14 is low.
[0034] Further, circulation line 48 is joined to valve stop control line 45 connecting between control valve 18 and valve stop oil pressure chamber 31 and is therefore constructed so as to supply pressure oil not through control valve 18 but directly to valve stop oil pressure chamber 31 .
[0035] Further, as seen from FIGS. 5A and 5B, the region H 2 where pressure oil is supplied to valve stop mechanism 14 to perform part cylinder operation with some of the cylinders kept out of operation is nearly included with the region H 1 where the operation angle phase of the intake valve is advanced from the maximumly retarded phase by phase control mechanism 12 thereby performing an advanced timing engine operation. Namely, when part cylinder operation is performed, it is desirable to advance the operation angle phase of the intake valve thereby retaining a predetermined torque by means of the remaining cylinders, while increasing an internal EGR thereby improving the fuel consumption and reducing the NOx emission. Accordingly, when oil pressure is supplied to valve stop mechanism 14 to start part cylinder operation, it is highly possible that phase control mechanism 12 is in a state of operation where the operation angle phase is advanced.
[0036] As indicated by arrows A 1 in FIGS. 5A and 5B, under an engine operating condition where the engine speed increases from the low-speed low-load range, the operating condition of phase control mechanism 12 is switched to the advance side simultaneously with switching to part cylinder operation. Further, as indicated by arrows A 2 , under an engine operating condition where the engine speed decreases from the high-speed low-load range, switching to the part cylinder operation is started during switching of phase control mechanism 12 to the advance side. Further, as indicated by arrows A 3 , even under an engine operating condition where the torque decreases from the high load range, switching to the part cylinder operation is started during switching of phase control mechanism 12 to the advance side. In this manner, when part cylinder operation is started, it is highly possible that phase control mechanism 12 has been switched to the advance side, i.e., it is highly possible that pressure oil is supplied through circulation line 48 to valve stop oil pressure chamber 31 , so that it becomes possible to make effectively higher the responsiveness of the hydraulic control system at the time of start of part cylinder operation.
[0037] In the meantime, in case phase control mechanism 12 is switched to the advance side under a condition where the oil pressure downstream of check valve 49 is high so that check valve 49 cannot be opened, such as the case where part cylinder operation is performed continuously, control valve 51 is adapted to open to enable pressure oil in retard side oil pressure chamber 27 to be discharged through advance side drain line 50 to oil pan 11 .
[0038] Further, at the time of full cylinder operation, the valve opening load of check valve 49 is lower than that of control valve (check valve) 51 and the oil pressure downstream of check valve 49 is low, so that when phase control mechanism 12 is switched to the advance side only check valve 49 is opened. Accordingly, pressure oil in retard side oil pressure chamber 27 is discharged through circulation line 48 , valve stop control line 45 and valve stop drain line 47 to oil pan 11 .
[0039] The entire contents of Japanese Patent Application P2001-12557 (filed Jan. 22, 2001) are incorporated herein by reference.
[0040] Although the invention has been described above by reference to a certain embodiment of the invention, the invention is not limited to the embodiment described above. Modifications and variations of the embodiment described above will occur to those skilled in the art, in light of the above teachings. For example, a flow restriction or orifice that generates a differential pressure can replace control valve 51 . The scope of the invention is defined with reference to the following claims.
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A hydraulic control system for an internal combustion engine is provided which comprises a first hydraulic operating mechanism and a second hydraulic operating mechanism, the first hydraulic operating mechanism and the second hydraulic operating mechanism being operated independently by oil pressure of a common oil press source, and a circulation line that supplies pressure oil discharged from the first hydraulic operating mechanism to the second hydraulic operating mechanism.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a suction cup assembly having a suction cup and holding device, and it more particularly relates to a suction cup assembly having a suction cup with a neck and a holding device which is removably attachable to the neck, the suction cup and the holding device each having one of a magnet and a magnetic metal for attaching them together to hold an article between them. The assembly can include a tether for attaching the holder to the suction cup or the magnet can be replaced with a sharp pin such as a thumbtack in which case the magnetic metal can be eliminated.
[0003] 2. Description of the Prior Art
[0004] There is a need in offices, schools and homes to hold and perhaps display pieces of paper, photographs, notes and other small, flat items. Often, tapes or other adhesives can be used to attach items to surfaces. Instead of adhesives, there are fixtures which can be used to hold and display these items. For example, a smaller wire fixture such as is shown in U.S. Pat. No. 1,230,242, can be used to hold sheets of paper and similar items. One embodiment of this fixture attaches to a button or knob but the fixture could be attached to a suction cup. Another method of hanging or holding small items such as papers, notices, pictures, recipes, flyers and the like, without requiring a hole in the small item, is with magnets. Clips attached to magnets or suction cups are also available for this purpose.
[0005] A problem with using adhesives to attach items to various smooth surfaces is that the adhesives often damage both the item being held and the surface to which the item adheres. A problem with wire fixtures which hold papers and the like is that each paper must have a hole from which it can be hung from the fixture. A separate problem with magnets as devices to attach items to flat surfaces is that the surface must be a magnetic metal to which a magnet could adhere. Clips themselves may be the cause of damage if the strength of the grip exceeds the toughness of the surface of the article or articles held in the clips.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide an assembly for holding paper and other items which combines a suction cup and a holding device, with means to detachably join the suction cup and the holding device.
[0007] It is another object of the present invention to provide an assembly for holding paper and other items which combines a suction cup and a holding device, one of which having a magnetic cap and the other having a magnet.
[0008] It is an another object of the present invention to provide an assembly which combines a suction cup with a magnet on a tether or a suction cup with a tether having a pin.
[0009] Another object of the present invention is to provide an assembly combining a resilient suction cup having a magnetic metal cap with a separable resilient tether having a magnet.
[0010] Another object of the present invention is to provide an assembly combining a resilient suction cup having a magnet for its cap with a separable resilient tether with a magnetic metal end.
[0011] Still another object of the present invention is to provide an assembly that can be used like a magnet on non-magnetic and non-metallic surfaces, such as glass, wood, plastic or stainless steel.
[0012] Still another object of the present invention is to provide an assembly that can be used like a thumbtack on non-porous surfaces, such as glass, wood, plastic or stainless steel.
[0013] Still another object of the present invention is to provide an assembly combining a resilient suction cup, and a tether with a holder containing either a magnet or magnetic material, or a pin, such that the assembly is inexpensive to manufacture, easy and economical to produce and assemble and attractive in appearance.
[0014] Yet another object of the present invention is to provide an assembly combining a suction cup and a tether with a holder containing either a magnet or a magnetic material, or a pin, such that the resulting assembly is sturdy.
[0015] Other objects will be apparent from the description to follow and from the appended claims.
[0016] The foregoing objects are achieved according to a preferred embodiment of the invention by means of a resilient suction cup having a tether attached on one end to the neck of the suction cup and having a magnet on its unattached end. The neck of the suction cup is capped with a magnetic metal cover, enabling the magnet to adhere to the suction cup and hold papers or other items placed between the magnetic metal and the magnet. In the alternative, the neck of the suction cup is capped with a magnet and the tether has a magnetic metal end, enabling the end of the tether to adhere to the suction cup and hold papers or other items placed between the magnetic metal and the magnet. The tether is preferably formed with the suction cup and is integral therewith.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a perspective view of the suction cup assembly with magnet disengaged.
[0018] [0018]FIG. 2 is a perspective view of the suction cup assembly with magnet engaged.
[0019] [0019]FIG. 3 is a top view of the suction cup assembly with magnet engaged.
[0020] [0020]FIG. 4 is a top view of the suction cup assembly with magnet dis-engaged.
[0021] [0021]FIG. 5 is a bottom view of the suction cup assembly with magnet engaged.
[0022] [0022]FIG. 6 is a bottom view of the suction cup assembly with magnet dis-engaged.
[0023] [0023]FIG. 7 is a side view of the suction cup assembly with magnet engaged.
[0024] [0024]FIG. 8 is a section taken along line A-A in FIG. 4 of the suction cup assembly with magnet dis-engaged.
[0025] [0025]FIG. 9 is a section taken along line B-B in FIG. 3 of the suction cup assembly with magnet engaged.
[0026] [0026]FIG. 10 is a perspective view of a second preferred embodiment of the suction cup assembly with tether dis-engaged.
[0027] [0027]FIG. 11 is a perspective view of a second preferred embodiment of the suction cup assembly with tether engaged.
[0028] [0028]FIG. 12 is a view through section A-A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] The preferred embodiments of the invention described below comprise a suction cup assembly with magnetic tether system as shown in the drawings, FIGS. 1 - 9 , comprising a suction cup 1 having a neck or nub 4 which can be covered by a magnetic cap 6 to which a magnet can adhere. The magnetic cap 6 can be made of a material, such as iron or steel, to which a magnet is attracted and will adhere. In a preferred embodiment, the neck 4 is cylindrical with an indentation 8 near the junction 10 with the suction cup 1 and the cap 6 is a magnetic metal. The cap 6 can have crimped edges 12 , enabling it to grasp the neck 4 of the suction cup in the indentation 8 . A tether 14 can be separably attached at one end 10 to the suction cup 1 at the junction 10 , or preferably molded with the suction cup and integral with it. The other end 16 of the tether 14 is attached to a holder 18 which contains a magnet 20 . In a preferred embodiment, the magnet 20 is riveted with rivet 22 and rivet cap 24 into the holder 18 . The suction cup, tether and holder can each be made of a resilient material such as rubber or rubber alloy or plastic, which could be elastometric plastic, or PVC.
[0030] A second preferred embodiment described below comprises a suction cup assembly with a tether system as shown in the drawings, FIGS. 10 - 12 , comprising a suction cup 101 having a neck or nub 104 . A tether 106 can be separably attached at one end 108 to the suction cup 101 at the junction 110 , or preferably molded with the suction cup and integral with it. The other end 112 of the tether 106 is attached to a holder 114 which contains a pin 116 protruding from the holder. The pin 116 can be engaged by or inserted into the neck 104 of the suction cup 101 or into a receiving piece (not shown), if desired.
[0031] In a preferred embodiment, the tether is between 2½ and 3 inches long and the cap is a circle which is 0.63 inches in diameter and 0.19 inches thick. In another preferred embodiment, the magnet is a cylinder whose diameter is 0.49 inches. In yet another preferred embodiment , the neck of the suction cup is a cylinder whose radius is 0.19 inches. However, the size can vary according to the use to which the suction cup is to have, and the area in which it is to be employed.
[0032] Although the cap and the magnet can be attached to the suction cup and holder as described above, they can be attached to the supporting structure in other ways as well. For example, either or both of them could be molded when the suction cup or tether are molded in an injection molding machine. In another embodiment, the sprue created during the injection molding process could serve as tether, linking the suction cup and the holder.
[0033] The invention can be used like a magnet on non-magnetic and non-metallic surfaces, such as glass, mirrors, wood, plastic or stainless steel. To use this invention, one suctions the suction cup onto a glass, stainless steel or other surface, places notes, pictures, flyers or other items onto the metal cap of the suction cup and then places the holder onto the items to engage the magnet and hold the items in place. The tether holds the magnet to the suction cup and prevents the magnet from becoming lost when not engaged. The invention is especially useful for hanging and displaying pictures, notes, flyers, and other items in lockers, kitchens and work areas. To use a second embodiment of this invention, one suctions the suction cup onto a surface, places notes, flyers or other items onto the neck of the suction cup and then pushes the pin contained in and protruding from the holder through the items and into the neck of the suction cup to secure the items.
[0034] The invention is particularly advantageous when formed of resilient materials such as plastic, rubber or rubber alloy but would apply to other materials as well. The invention could be virtually any size suction cup, tether and magnet or pin. The suction cup, tether and magnetic or non-magnetic holder can be integral, and can be molded in one molding operation; the magnet and the cap, or pin (in lieu of magnet and cap), could be inserted as well during the molding process, making the manufacturing process inexpensive, as opposed particularly to manual assembly. Variations in the foregoing description fall within the invention.
[0035] The invention has been described in detail with particular emphasis being placed on the preferred embodiments thereof, but variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains.
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The present invention provides a suction cup assembly having a magnetic tether system attached to a suction cup. The assembly includes a resilient suction cup, tether, holder and magnet. This assembly enables a suction cup to hold items on non-magnetic, smooth surfaces using a magnet.
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Latin name of the genus and species claimed: Dianthus Caryophyllus.
Variety denomination: FLORIAMETRINE.
FIELD OF THE INVENTION
The present invention relates generally to the field of genetic modification of plants. More particularly, the present invention is directed to genetically-modified carnation plants expressing unique color phenotypes in selected parts of the plants.
BACKGROUND OF THE INVENTION
The flower or ornamental plant industry strives to develop new and different varieties of flowers and/or plants. An effective way to create such novel varieties is through the manipulation of flower color. Classical breeding techniques have been used with some success to produce a wide range of colors for almost all of the commercial varieties of flowers and/or plants available today. This approach has been limited, however, by the constraints of a particular species' gene pool and for this reason it is rare for a single species to have the full spectrum of colored varieties. For example, the development of novel colored varieties of plants or plant parts such as flowers, foliage and stems would offer a significant opportunity in both the cut flower and ornamental markets. In the flower or ornamental plant industry, the development of desired (including novel) colored varieties of carnation is of particular interest. This includes not only different colored flowers but also anthers and styles.
Flower color is predominantly due to three types of pigment: flavonoids, carotenoids and betalains. Of the three, the flavonoids are the most common and contribute a range of colors from yellow to red to blue. The flavonoid molecules that make the major contribution to flower color are the anthocyanins, which are glycosylated derivatives of cyanidin and its methylated derivative peonidin, delphinidin and its methylated derivatives petunidin and malvidin and pelargonidin. Anthocyanins are localized in the vacuole of the epidermal cells of petals or the vacuole of the sub epidermal cells of leaves.
The flavonoid pigments are secondary metabolites of the phenylpropanoid pathway. The biosynthetic pathway for the flavonoid pigments (flavonoid pathway) is well established, (Holton and Cornish, Plant Cell 7:1071-1083, 1995; Mol et al., Trends Plant Sci. 3:212-217, 1998; Winkel-Shirley, Plant Physiol. 126:485-493, 2001a; and Winkel-Shirley, Plant Physiol. 127:1399-1404, 2001b, Tanaka and Mason, In Plant Genetic Engineering, Singh and Jaiwal (eds.) SciTech Publishing Llc., USA, 1: 361-385, 2003, Tanaka et al., Plant Cell, Tissue and Organ Culture 80: 1-24, 2005, Tanaka and Brugliera, In Flowering and Its Manipulation, Annual Plant Reviews Ainsworth (ed.), Blackwell Publishing, UK, 20: 201-239, 2006). Three reactions and enzymes are involved in the conversion of phenylalanine to p-coumaroyl-CoA, one of the first key substrates in the flavonoid pathway. The enzymes are phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H) and 4-coumarate: CoA ligase (4CL). The first committed step in the pathway involves the condensation of three molecules of malonyl-CoA (provided by the action of acetyl CoA carboxylase (ACC) on acetyl CoA and CO 2 ) with one molecule of p-coumaroyl-CoA. This reaction is catalyzed by the enzyme chalcone synthase (CHS). The product of this reaction, 2′,4,4′,6′, tetrahydroxy-chalcone, is normally rapidly isomerized by the enzyme chalcone flavanone isomerase (CHI) to produce naringenin. Naringenin is subsequently hydroxylated at the 3 position of the central ring by flavanone 3-hydroxylase (F3H) to produce dihydrokaempferol (DHK).
The pattern of hydroxylation of the B-ring of DHK plays a key role in determining petal color. The B-ring can be hydroxylated at either the 3′, or both the 3′ and 5′ positions, to produce dihydroquercetin (DHQ) or dihydromyricetin (DHM), respectively. Two key enzymes involved in this part of the pathway are flavonoid 3′-hydroxylase (F3′H) and flavonoid 3′, 5′-hydroxylase (F3′5′H), both members of the cytochrome P450 class of enzymes.
The production of colored anthocyanins from the dihydroflavonols (DHK, DHQ, DHM), involves dihydroflavonol-4-reductase (DFR) leading to the production of the leucoanthocyanidins. The leucoanthocyanidins are subsequently converted to the anthocyanidins, pelargonidin, cyanidin and delphinidin. These flavonoid molecules are unstable under normal physiological conditions and glycosylation at the 3-position, through the action of glycosyltransferases, stabilizes the anthocyanidin molecule thus allowing accumulation of the anthocyanins.
The substrate specificity shown by DFR can regulate the anthocyanins that a plant accumulates. Petunia and cymbidium DFRs do not reduce DHK and thus they do not accumulate pelargonidin-based pigments (Forkmann and Ruhnau, Z Naturforsch C. 42c, 1146-1148, 1987, Johnson et al., Plant Journal, 19, 81-85, 1999). Many important floricultural species including iris, delphinium, cyclamen, gentian, cymbidium are presumed not to accumulate pelargonidin due to the substrate specificity of their endogenous DFRs (Tanaka and Brugliera, 2006, supra).
In carnation, the DFR enzyme is capable of metabolizing two dihydroflavonols to leucoanthocyanidins which are ultimately converted through to anthocyanins pigments that are responsible for flower color. DHK is converted to leucopelargonidin, the precursor to pelargonidin-based pigments, giving rise to apricot to brick-red colored carnations. DHQ is converted to leucocyanidin, the precursor to cyanidin-based pigments, producing pink to red carnations. Carnation DFR is also capable of converting DHM to leucodelphinidin (Forkmann and Ruhnau, 1987 supra), the precursor to delphinidin-based pigments. However, naturally occurring carnation lines do not contain a F3′5′H enzyme and therefore do not synthesize DHM.
Nucleotide sequences encoding F3′5′Hs have been cloned (see International Patent Application No. PCT/AU92/00334 incorporated herein by reference and Holton et al., Nature, 366:276-279, 1993 and International Patent Application No. PCT/AU03/01111 incorporated herein by reference). These sequences were efficient in modulating 3′, 5′ hydroxylation of flavonoids in petunia (see International Patent Application No. PCT/AU92/00334 and Holton et al., 1993 supra), tobacco (see International Patent Application No. PCT/AU92/00334), carnations (see International Patent Application No. PCT/AU96/00296 incorporated herein by reference) and roses (see International Patent Application No. PCT/AU03/01111).
Carnations are one of the most extensively grown cut flowers in the world.
There are thousands of current and past cut-flower varieties of cultivated carnation. These are divided into three general groups based on plant form, flower size and flower type. The three flower types are standards, sprays and midis. Most of the carnations sold fall into two main groups, the standards and the sprays. Standard carnations are intended for cultivation under conditions in which a single large flower is required per stem. Side shoots and buds are removed (a process called disbudding) to increase the size of the terminal flower. Sprays and/or miniatures are intended for cultivation to give a large number of smaller flowers per stem. Only the central flower is removed, allowing the laterals to form a ‘fan’ of flowers.
Spray carnation varieties are popular in the floral trade, as the multiple flower buds on a single stem are well suited to various types of flower arrangements and provide bulk to bouquets used in the mass market segment of the industry.
Standard and spray cultivars dominate the carnation cut-flower industry, with approximately equal numbers sold of each type in the USA. In Japan, spray-type varieties account for 70% of carnation flowers sold by volume, whilst in Europe spray-type carnations account for approximately 50% of carnation flowers traded through out the Dutch auctions. The Dutch auction trade is a good indication of consumption across Europe.
Whilst standard and midi-type carnations have been successfully manipulated genetically to introduce new colors (Tanaka and Brugliera, 2006, supra; see International Patent Application No. PCT/AU96/00296), this has not been applied to spray carnations. There is an absence of blue color in color-assortment in carnation, only recently filled through the introduction of genetically-modified standard-type carnation varieties. However, standard-type varieties cannot be used for certain purposes, such as bouquets and flower arrangements where a large number of smaller carnation flowers are needed, such as hand-held arrangements, and small table settings.
One particular spray carnation which is particularly commercially popular is the Kortina Chanel line of carnations ( Dianthus caryophyllus cv. Kortina Chanel). The variety has excellent growing characteristics and a moderate to good resistance to fungal pathogens such as Fusarium. There are a number of varieties which have been released as “sports” of Kortina Chanel. These include Kortina, Royal Red Kortina, Cerise Kortina and Dusty Kortina. However, before the advent of the present invention, purple/blue spray carnations were not available.
SUMMARY OF THE INVENTION
The following traits represent the characteristics of the new Dianthus cultivar ‘FLORIAMETRINE’. These traits distinguish this cultivar from other commercial varieties. ‘FLORIAMETRINE’ may exhibit phenotypic differences with variations in environmental, climatic and cultural conditions, without any variance in genotype.
1. Dianthus ‘FLORIAMETRINE’ exhibits pronounced spray habit. 2. Dianthus ‘FLORIAMETRINE’ blooms profusely. 3. Dianthus ‘FLORIAMETRINE’ exhibits bright purple/violet flowers (RHS N78A). 4. Dianthus ‘FLORIAMETRINE’ exhibits green (RHS 137A) foliage. 5. At maturity, the height of the foliage mound of Dianthus ‘FLORIAMETRINE’ is 89 cm. The mature width about 15 to 18 cm. 6. Dianthus ‘FLORIAMETRINE’ is a perennial. 7. Dianthus ‘FLORIAMETRINE’ is suitable for use as a flowering plant in pots, containers, window boxes and the garden, but is primarily suited for the production of cut flowers. 8. Dianthus ‘FLORIAMETRINE’ is not hardy and is grown in a greenhouse.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying color drawing illustrates the overall appearance of the new variety Dianthus ‘FLORIAMETRINE’ showing colors as true as reasonably possible to obtain in colored reproductions of this type. Colors in the drawing may differ from the color values cited in the detailed botanical description, which accurately describe the actual colors of the new variety ‘FLORIAMETRINE’.
FIG. 1 is a photographic representation of the flower. Colors may appear different from the actual colors due to light reflection but are as accurate as possible by conventional photography.
FIG. 2 is a diagrammatic representation of the binary plasmid pCGP2442. Selected restriction endonuclease sites (AscI, PacI, PmeI) are marked. Abbreviations include LB=Left Border from A. tumefaciens Ti plasmid; RB=Right Border region from A. tumefaciens Ti plasmid; TetR=tetracycline resistance gene complex.
FIG. 3 is a photographic representation of a high resolution scan of a Southern blot autoradiograph showing 10 μg of EcoRI-treated genomic DNA from the transgenic carnation line 19907, in comparison to 10 μg of EcoRI-treated genomic DNA from the carnation lines Kortina Chanel, Vega and Purple Spectro, hybridized with the NtALS probe.
FIG. 4 is a photographic representation of the ‘Kortina Chanel’ control on the left and the cultivar ‘FLORIAMETRINE’ on the right.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention relates to a new and distinct cultivar of carnation that is grown for use as a flowering plant for pots and containers. The new cultivar is known botanically as Dianthus caryophyllus and is referred to hereinafter by the cultivar name ‘FLORIAMETRINE’.
‘FLORIAMETRINE’ is a complex transgenic plant comprising genetic sequences encoding at least two F3′5′H molecules and at least one DFR. The vector pCGP2442 used to transform meristematic cells contains a chimeric AmCHS 5′: Salivia F3′5′H#47: petD8 3′ gene in tandem with a petunia genomic DFR-A gene, a chimeric carnANS 5′: BPF3′5′H#18: carnANS 3′ gene and the 35S 5′: SuRB selectable marker gene cassette of the plasmid pWTT2132.
The new variety originated in vitro by Agrobacterium tumefaciens -mediated transformation of meristematic cells of the Kortina Chanel (unpatented) carnation with the pCGP2442 vector at Florigene Pty Ltd., in Bundoora, Victoria, Australia. Cuttings of Dianthus caryophyllus cv. Kortina Chanel were obtained from Van Wyk and Son Flower Supply, Victoria or Propagation Australia, Queensland, Australia. Transgenic plants containing the chimeric AmCHS 5′: SaliviaF3′5′H#47: petD8 3′ gene in tandem with a petunia genomic DFR-A gene, and a chimeric carnANS 5′: BPF3′5′H#18: carnANS 3′ gene were successfully generated from the cells. In addition to these genes, the plants also contains genes for acetolactate synthase resistance (SuRB) transformation selection markers. The transformation and regeneration process is described in International Patent Application No. PCT/US92/02612; International Patent Application No. PCT/AU96/00296; and Lu et al., Bio/Technology 9: 864-868, 1991, the contents of each of which are incorporated by reference.
The primary focus of the carnation generation program was to produce new cultivars of carnations which exhibited a selected and desired purple/violet color in the spray background. The term ‘FLORIAMETRINE’ was selected because of its pronounced production of delphinidin or delphinidin-based molecules pigments.
The new variety was selected from a group of 74 transgenic lines of which only three produced flowers with a significant shift in color into the violet, purple/violet range. ‘FLORIAMETRINE’ is essentially similar to the parent in the morphological aspects of the flower, but can be further distinguished from the parent throughout the accumulation of pigment in the filaments and anthers of the flower. This is a new phenotype of the transgenic line. Some styles and anthers of ‘FLORIAMETRINE’ also have a shift in color to light purple, whereas the styles and anthers from flowers of the parent line were a cream-white color.
The new variety was originally selected in vitro as a regenerated shoot from a ‘Kortina Chanel’ carnation meristematic cell that had been transfected with Agrobacterium tumefaciens AGL0 (Lazo et al., Bio/technology 9:963-967, 1991) carrying the plasmid pCGP2442.
Asexual reproduction of the new cultivar was first accomplished in 2007 in a cultivated area of Bundoora, Victoria, Australia. The method of asexual propagation used was vegetative cuttings. Since that time the characteristics of the new cultivar have been determined stable and are reproduced true to type in successive generation of asexual reproduction.
BOTANICAL DESCRIPTION OF THE PLANT
The following is a detailed description of the new cultivar ‘FLORIAMETRINE’. Data was collected from plants grown indoors in Bundoora, Victoria, Australia. The color determinations are in accordance with the 2001 edition of The Royal Horticultural Society (R.H.S.) Colour Chart except where general color terms of ordinary dictionary significance are used. Growing conditions are typical to other species, sports and lines of Dianthus.
Botanical classification: Dianthus caryophyllus. Species: Caryophyllus. Common name: Kortina Chanel. Commercial classification: Dianthus caryophyllus 19907. Type: Perennial. Use: Used as a flowering plant for pots and containers. Parentage: ‘FLORIAMETRINE’ is a transgenic plant that resulted from the transformation of D. caryophyllus with the transformation vector, pCGP2442.
TABLE 1
Plant Description
Bloom period
All year
Plant habit
Spray type carnation
Plant height
Average plant height at flowering—
891 mm
Plant width
About 150 to 180 mm at flowering
Plant hardiness
Not tested for hardiness
Root system
Fine fibrous root system
Propagation
Vegetative propagation
Cultural requirements
Grown hydroponically in a
greenhouse. Plants fertilized via
drip irrigation system
Pests and diseases
Susceptible to known Dianthus pest
and diseases
Time and Temperature needed to
About 3 to 4 weeks to produce
produce a rooted cutting
rooted cuttings, bench heat: 18-22°
C., Air temp approximately 15 to
22° C.
Crop time
Average days to flowering: 107.
Stem shape
Cylindrical, Average stem length
782 mm, Average stem diameter at
5th node: 6 mm
Stem surface
Glabrous and glaucous
Stem color
137B
Branching
Little branching from the axils of
lower leaves
Internode length
Average length of 5th internode:
73 mm
Node color
192D
Node dimensions
About 6 mm diameter and about 3
mm in length
Foliage
Type
Evergreen
Shape
Linear
Division
Simple
Apex
Acute
Base
Decurrent
Venation
Not prominent
Margins
Entire
Attachment
Sheathing
Arrangement
Opposite and spiraling up stem
Surfaces
Glaucous
Leaf dimensions
3rd leaf from flower, Average
length: 40.5 mm, Average width: 7
mm
Leaf color
137A
Fragrance
Absent
Flowers
Inflorescence
Cymose
Flower type
Saliform, double and symmetrical
Flower dimensions
Average corolla height: 22.5 mm,
(including calyx)
Average calyx height: 32.5 mm
Fragrance
Absent
Bud color
191B
Anthocyanin
Present
Bud dimensions
Average bud length: 26.4 mm,
Average bud width: 9 mm
Bud shape
Cylindrical
Petals
Persistent, apopetalous, overlapping
Petal number
Average number of petals: 27
Petal margin
Denate
Petal shape
Obtetoid
Petal surface
Glabrous
Petal dimensions
Average petal length: 47 mm,
Average petal width: 22 mm
Ground color of blade
N78A
Color of band around centre
N78A
Color of middle of strap
145C
Color of base of strap
145D
Calyx dimensions
Average calyx length: 32.5 mm,
Average calyx diameter at apex:
14.5 mm
Calyx color
138B
Anthocyanin
Absent
Sepals
Average number of sepals: 6
Fused or Unfused
Unfused
Sepal color
138B
Anthocyanin
Absent
Peduncle dimensions
Average peduncle length: 33.6 mm,
Average peduncle width: 2 mm
Peduncle color
138A
Peduncle surface
Glaucous
Epicalyx
Present
Bracts
1 pair in number (2 individual
bracts)
Bracts dimensions
About 3 mm by about 20 mm
Bract color
138A
Anthacyanin
Absent
Bracteoles
1 or 2 pair
Dimensions
About 3 mm by about 25 mm
Anthocyanin
Absent
Stipules
Absent
Stipules dimensions
N/A
Stipule color
N/A
Anthacyanin
N/A
Lastiness of flowers
14 days
Reproductive Organs
Stamens
Average number of stamens: 10
Stamen dimensions
Average length of stamen: 21.5 mm
Stamen color
Upper: N80C, Lower: N155B
Anther number
Average of normal anthers: 2,
Average of abnormal anthers: 6
Anther attachment
Dorsifixed
Anther color
N80C
Anther dimensions
Average anther length: 1.84 mm,
Average anther width: 0.68 mm
Pollen
Little pollen
Pistil
One that divides into 2 above the
ovary
Pistil dimensions
Average pistil length: 34 mm
Styles
Average No: 2, Average length: 26
mm
Style color
N155B
Stigma number
Single
Stigma shape
A single stigma
Stigma color
N155B
Height above petals
Stigma does not protrude above
petals
Ovary postion
Superior
Ovary dimensions
Average ovary height: 8 mm,
Average ovary width: 5.5 mm
Ovary shape
Obovoid
Ovary color
Upper: 145A, Lower: 155A
Seed
Absent
TABLE 2
Floriametrine
Kortina Chanel control
Description
Bloom period
All year
All year
Plant habit
Spray type carnation
Spray type carnation
Plant height
Average plant height at
Average plant height at
flowering —895 mm
flowering —853 mm
Plant width
150 to 180 mm at
150 to 180 mm at
flowering
flowering
Plant hardiness
Not tested for hardiness
Not tested for hardiness
Root system
Fine fibrous root system
Fine fibrous root system
Propagation
Vegetative propagation
Vegetative propagation
Cultural
Grown hydroponically
Grown hydroponically in
requirements
in a greenhouse. Plants
a greenhouse. Plants
fertilized via drip
fertilized via drip
irrigation system
irrigation system
Pests and diseases
Susceptible to known
Susceptible to known
Dianthus pest and
Dianthus pest and
diseases
diseases
Time and
3 to 4 weeks to produce
3 to 4 weeks to produce
Temperature
rooted cuttings, bench
rooted cuttings, bench
needed to
heat: 18-22° C., Air
heat: 18-22° C., Air temp
produce a
temp approx. 15 to
approx. 15 to 22° C.
rooted cutting
22° C.
Crop time
Average days to
Average days to
flowering: 107.
flowering: 108
Stem shape
Cylindrical, Ave stem
Cylindrical, Ave stem
length 782 mm, Ave
length 713 mm, Ave.
stem diameter at 5 th
stem diameter at 5 th node:
node: 6 mm
6.7 mm
Stem surface
Glabrous and glaucous
Glabrous and glaucous
Stem color
137B
137B
Branching
Little branching from
Little branching from the
the axils of lower leaves
axils of lower leaves
Internode length
Average length of 5 th
Average length of 5 th
internode: 73 mm
internode: 73 mm
Node color
192D
192D
Node dimensions
6 mm diameter and
6 mm diameter and 3 mm
3 mm in length
in length.
Foliage
Type
Evergreen
Evergreen
Shape
Linear
Linear
Division
simple
simple
Apex
Acute
Acute
Base
Decurrent
Decurrent
Venation
Not prominent
Not prominent
Margins
Entire
Entire
Attachment
Sheathing
Sheathing
Arrangement
Opposite and spiraling up
Opposite and spiraling
stem
up stem
Surfaces
Glaucous
Glaucous
Leaf dimensions
3 rd leaf from flower, Ave
3 rd leaf from flower, Ave
length: 40.5 mm, Ave
length: 39 mm, Ave
width: 7 mm
width: 8 mm
Leaf color
137A
137A
Fragrance
Absent
Absent
Flowers
Inflorescence
Cymose
Cymose
Flower type
Saliform, double and
Saliform, double and
symmetrical
symmetrical
Flower dimensions
Ave. corolla height:
Ave corolla height:
including
22.5 mm, Ave calyx
23.5 mm, Ave. calyx
calyx)
height: 32.5
height: 31.5 mm
Fragrance
Absent
Absent
Bud color
191B
191B
Anthocyanin
Present
Present
Bud dimensions
Ave bud length:
Ave bud length: 24.9 mm,
26.4 mm, Ave bud
Ave bud width: 9.9 mm
width: 9 mm
Bud shape
Cylindrical
Cylindrical
Petals
Persistent, apopetalous,
Persistent, apopetalous,
overlapping
overlapping
Petal number
Ave number of petals:
Ave number of petals: 32
27
Petal margin
Denate
Denate
Petal shape
Obtetoid
Obtetoid
Petal surface
Glabrous
Glabrous
Petal dimensions
Ave petal length:
Ave petal length: 47 mm,
47 mm, Ave petal
Ave petal width: 22 mm
width: 22 mm
Ground color
N78A
65A
of blade
Color of band
N78A
65A
around centre
Color of middle
145C
145C
of strap
Color of base
145D
145D
of strap
Calyx dimensions
Ave calyx length:
Ave calyx length: 31.5 mm,
32.5 mm, Ave calyx
Ave calyx diameter at
diameter at apex:
apex: 14.9 mm
14.5 mm
Calyx color
138B
138B
Anthocyanin
Absent
Absent
Sepals
Ave number of sepals:
Ave number of sepals:
6
5.4
Fused or Unfused
Unfused
Unfused
Sepal color
138B
138B
Anthocyanin
absent
absent
Peduncle
Ave peduncle length:
Ave peduncle length:
dimensions
33.6 mm, Ave peduncle
45.2 mm, Ave peduncle
width: 2 mm
width: 2.4
Peduncle color
138A
138A
Peduncle surface
Glaucous
Glaucous
Epicalyx
Present
Present
Bracts
1 pair in number (2
1 pair in number (2
individual bracts)
individual bracts)
Bracts dimensions
3 mm × 20 mm
3 mm × 20 mm
Bract color
138A
138A
Anthacyanin
absent
absent
Bracteoles
1 or 2 pair
1 or 2 pair
Dimensions
3 mm × 25 mm
3 mm × 25 mm
Anthocyanin
Absent
Absent
The Dianthus ‘FLORIAMETRINE’ is now described by the following non-limiting Examples.
EXAMPLE 1
GENERATION OF DIANTHUS ‘FLORIAMETRINE’
In order to increase the levels of delphinidin-based anthocyanins and therefore increase the chance of violet/purple/blue color in the Kortina Chanel spray carnation flowers, a novel construct was prepared that included the use of two F3′5′H chimeric genes and a petunia DFR gene.
The DFR genomic fragments used in this application were isolated from petunia. The petunia DFR enzyme is only capable of using DHQ and DHM as a substrate, but not DHK (Holton and Cornish, 1995 supra). This ensures that most or all of the anthocyanidin produced is delphinidin.
The F3′5′H coding sequences in the chimeric genes used in the new construct were from pansy (carnANS 5′: BP F3′5′H #18: carnANS 3′ in pCGP2205) and salvia (AmCHS 5′: Salvia F3′5′H #47: petD8 3′ in pCGP2122) as these represent the two expression cassettes that were the most efficient in producing the highest levels of delphinidin in the Kortina Chanel spray carnation.
Preparation of the Transformation Vector, pCGP2442
The transformation vector pCGP2442 ( FIG. 2 ) contains a chimeric AmCHS: Salvia F3′5′H#47: petD8 3′ gene in tandem with a petunia genomic DFR-A gene, a chimeric carnANS 5′: BPF3′5′H#18: carnANS 3′ gene and the 35S 5′: SuRB selectable marker gene cassette of the plasmid pWTT2132 (see International Patent Application No. PCT/AU03/01111 incorporated herein by reference).
Agrobacterium tumefaciens Strains and Transformations
The disarmed Agrobacterium tumefaciens strain used was AGL0 (Lazo et al., 1991 supra).
Plasmid DNA was introduced into the Agrobacterium tumefaciens strain AGL0 by adding 5 μg of plasmid DNA to 100 μL of competent AGL0 cells prepared by inoculating a 50 mL LB culture (Sambrook et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratories, Cold Spring Harbor, N.Y., USA, 1989) and incubation for 16 hrs with shaking at 28° C. The cells were then pelleted and resuspended in 0.5 mL of 85% (v/v) 100 mM CaCl 2 /15% (v/v) glycerol. The DNA- Agrobacterium mixture was frozen by incubation in liquid N 2 for 2 minutes and then allowed to thaw by incubation at 37° C. for 5 minutes. The DNA/bacterial mix was then placed on ice for a further 10 minutes. The cells were then mixed with 1 mL of LB (Sambrook et al., 1989 supra) media and incubated with shaking for 16 hrs at 28° C. Cells of A. tumefaciens carrying the plasmid were selected on LB agar plates containing appropriate antibiotics such as 50 μg/mL tetracycline or 100 μg/mL gentamycin. The confirmation of the plasmid in A. tumefaciens was done by restriction endonuclease mapping of DNA isolated from the antibiotic-resistant transformants.
Plant transformations were as described in International Patent Application No. PCT/US92/02612 or International Patent Application No. PCT/AU96/00296 or Lu et al., Bio/Technology 9: 864-868, 1991 each incorporated herein by reference.
Cuttings of Dianthus caryophyllus cv. Kortina Chanel were obtained from Van Wyk and Son Flower Supply, Victoria or Propagation Australia, Queensland, Australia.
EXAMPLE 2
DETECTION OF THE SURB CHIMERIC GENE FROM THE TRANSFORMATION VECTOR PGP2442 IN DIANTHUS ‘FLORAMETRINE’ PLANTS
In order to determine stable transformation of Dianthus caryophyllus with the T-DNA from the transformation vector pCGP2442, transgenic plants were analyzed by Southern blot. The results are shown in FIG. 3 .
Preparation of Genomic DNA and Southern Analysis
Genomic DNA was isolated from leaf tissues as described by Dellaporta et al., Molecular Biology Reporter 1(14):19-21, 1983. The genomic DNA (10 μg) was digested for 48 hours using 120 units of the restriction endonuclease EcoRI at 37° C. DNA fragments were separated by electrophoresis through a 0.8% w/v agarose gel. The DNA was transferred to Hybond NX membrane (Amersham) as described (Sambrook et al., 1989 supra).
The following samples were analyzed:
1. HindIII-treated λDNA standard markers (size range: 23.13, 9.42, 6.56, 4.36, 2.32, 2.03 kb), 2. 10 μg of EcoRI-treated genomic DNA from transgenic carnation line 19907 (FLORIAMETRINE), 3. 10 μg of EcoRI-treated genomic DNA from non-transgenic carnation parental line, Kortina Chanel, 4. 10 μg of EcoRI-treated genomic DNA from non-transgenic carnation line, Vega; and 5. 10 μg of EcoRI-treated genomic DNA from non-transgenic carnation line, Purple Spectro.
Following electrophoresis, the gel was prepared for blotting by a 15 minute depurination step in 0.25 M HCl, two 20 minute washes in denaturing solution (1.5 M NaCl, 0.5 M NaOH) and two 20 minute washes in neutralization solution (0.5 M Tri-HCl, pH 7.5, 0.48 M HCl, 1.5 M NaCl). DNA was capillary transferred to Hybond-NX nylon membrane (Amersham Biosciences, UK) in 20×SSC (3 M NaCl, 0.3 M Tris-Na citrate, pH 7.0).
Preparation of Probes
A probe corresponding to a 770 bp fragment of the ALS (acetolactate synthase) gene from Nicotiana tabacum (NtALS) was used for Southern blot analysis. The probe fragment was originally generated by PCR and subsequently sub-cloned into an amplification vector (pBluescript II, Stratagene, USA), given a reference number (pCGP1651) and the fragment sequenced. After confirmation of the correct sequence, the DNA fragment was isolated from the source plasmid using the restriction endonuclease HindIII. The fragment was separated by 1% w/v agarose gel electrophoresis and purified using the MinElute Gel Extraction kit and protocol (Qiagen, Australia).
32P-Labeling of DNA Probes
DNA fragments (25-50 ng) were labeled with 50 μCi of [α-32P]-dCTP (PerkinElmer Life and Analytical Sciences, USA) using a Decaprime kit (Ambion, USA). Unincorporated [α- 32 P]-dCTP was removed by chromatography on Sephadex G-50 (Fine) columns. The labeled probe fragment was counted using a BioScan radioisotope counter (QC:4000 XER, BioScan, USA).
Hybridization and Detection
Membranes were pre-hybridized in 10 mL hybridization buffer 50% v/v deionized formamide, 1 M NaCl, 1% w/v SDS and 10% w/v dextran sulfate) at 42° C. for 1 hr. Once denatured, 10,000,000 dpm of 32 P -labeled probe was added to the hybridization solution and hybridization was continued at 42° C. for a further 16 hours. Membranes were washed twice in low stringency buffer (2×SSC, 1% w/v SDS) at 65° C. for 30 minutes. Membranes were exposed to Kodax BioMax MS X-Ray film (Kodak, USA) with an intensifying screen at −70° C. for 16 hours. The exposed films were automatically developed using a Curix 60 X-ray developer (AGFR-Gevaert Group, Belgium).
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A new cultivar of Dianthus plant named ‘FLORIAMETRINE’ is characterized inter alia by altered inflorescence with respect to tissue and/or organelles including flowers or flower parts. This trait sets ‘FLORIAMETRINE’ apart from all other existing varieties, lines, strains or sports of Dianthus. In particular, Dianthus ‘FLORIAMETRINE’ has bright purple/violet flowers.
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FIELD
Embodiments of the present invention relate to circuits, and more particularly, to a bus in a computer or microprocessor system.
BACKGROUND
A bottleneck in microprocessor design is the use of long on-chip buses. In deep sub-micron process technology, the aspect ratio for intermediate wire layers is 2.0 or above. This indicates that as wire pitch decreases and interconnect aspect ratio increases, the lateral component of interconnect capacitance (coupling capacitance), which may be from three to five times as much as the vertical component of interconnect capacitance, will likely continue to grow so as to dominate the total interconnect capacitance of a bus. Interconnect capacitance affects bus delay and power dissipation.
In addition to capacitance effects, it has been shown that the resistance of interconnects may increase significantly when the lateral dimensions of the interconnects (width and height) are scaled to the sub-100 nanometer regime. This is due to the scattering processes of the conduction electrons at the external interfaces, e.g. interconnect surfaces, and at the internal interfaces, e.g., grain boundaries in the interconnects.
In addition to reducing the capacitance and resistance of buses, it may also be desirable to provide for a bus architecture that helps mitigate the effect of capacitance and resistance upon bus delay and power dissipation.
It has been shown that a significant savings in power (or energy) dissipation may be achieved if the number of bus lines is reduced by one-half, while keeping the same bus area and double-pumping each interconnect (serial link), e.g., multiplexing each two bits on one interconnect. This is discussed in M. Ghoneima, et al., “Serial Link Bus: A Low Power On-Chip Bus Architecture,” Proceedings of the ICCAD, November 2005. A reason for this reduction power dissipation is that if the number of bus interconnects is halved, where the same bus area is maintained, then the line pitch almost doubles. This increase in pitch allows an increase in the interconnect spacing and (or) the interconnect width, which in turn reduces the interconnect capacitance and (or) resistance. More generally, there may be a reduction in power dissipation where the number of bus lines is divided by an integer divisor, d, and the data pumping is increased by a factor equal to d, where d may be greater than two.
In order for the d-pumped bus to maintain the same throughput of the conventional parallel line bus, d bits must be transmitted within the same clock period on each interconnect. Thus, the interconnect delay of the d-pumped bus must be d times less than that of the conventional parallel-line bus. Simulations have shown that the relative reduction in serial link delay may be greater than the factor d, leading to an overall throughput increase. For example, simulations have shown that by halving the number of bus lines and double-pumping the data, the relative reduction in serial link delay is much better than 50%, and this is expected to further improve as technology scales to smaller dimensions (because C C /C G increases as technology scales). This indicates that a double-pumped serial-link with a line pitch double that of a conventional static bus may be structured to have a higher throughput. If, however, the throughput of the serial-link bus is to be kept the same as that of a conventional bus, then the extra reduction in delay (the delay slack) can be used to reduce the number of repeaters and their relative sizes. As a result, the reduction in repeater capacitance, together with the reduced serial-link capacitance, leads to an overall energy reduction when compared to a conventional static bus.
It is useful to provide a bus architecture with a further reduction in power dissipation.
The average activity factor of a line AF represents the probability that a line will switch from high to low or vice versa within a clock cycle. Each line in a conventional parallel line bus transmits one bit during each cycle, so the average activity factor of this line can vary between 0 and 1. However, as a line in a d-pumped bus serializes d bits in the same clock cycle, the average activity factor of a d-pumped line varies between 0 and d. For example, a double-pumped line will vary between 0 and 2
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates plots of the activity factor of a serial data stream formed from two data streams.
FIG. 2 illustrates an embodiment of the present invention for the case in which the activity factors of the two data streams sum to less than 1.
FIG. 3 illustrates an embodiment of the present invention for the case in which the activity factors of the two data streams sum to greater than 1.
FIG. 4 illustrates a flow diagram according to an embodiment of the present invention.
FIG. 5 illustrates an embodiment combining the features of FIGS. 2 and 3 according to an embodiment of the present invention.
FIG. 6 illustrates a flow diagram for allocating pitch according to activity factors according to an embodiment of the present invention.
FIG. 7 illustrates a portion of a computer system in which embodiments of the present invention may find application.
DESCRIPTION OF EMBODIMENTS
Before describing the embodiments, it is useful to discuss the energy dissipation and coupling capacitance of a bus.
The delay of an interconnect is a strong function of its total capacitance, C T , which is the sum of the line-to-ground capacitance, load capacitance, and the coupling capacitance. This may be expressed for an interconnect indexed by the index i as
C T ( i ) = C G ( i ) + ∑ j M ( i ; j ) C C ( i ; j ) ,
where C T (i) is the total capacitance for interconnect i, C G (i) represents the line-to-ground and load capacitance for interconnect i, C C (i; j) is the coupling capacitance between interconnect i and interconnect j, M(i; j) is the Miller coupling factor between interconnects i and j. The sum over the index j such that interconnect j is a neighbor to interconnect i.
The Miller coupling factor between any two neighboring interconnects depends on their relative switching activity. For two oppositely switching neighboring interconnects, the Miller coupling factor is approximately 2, whereas if only one interconnect is switching and the other neighbor is quiet, the Miller coupling factor is approximately 1. For two similarly switching neighboring interconnects, the Miller coupling factor is approximately 0.
The average dynamic energy dissipation of bus interconnect i, E DYN (i), may be written as follows:
E DYN ( i ) = 0.5 AF ( i ) C T V DD 2 = 0.5 AF ( C G ( i ) + ∑ j M ( i ; j ) C C ( i ; j ) ) V DD 2 ,
where V DD is a rail voltage, e.g., a supply voltage. The activity factor AF is 1 if the interconnect is switching, and is 0 if it is quiet.
If two data streams with activity factors 0<AF 1 <1 and 0<AF 2 <1 are multiplexed onto a serial link, it can be shown that the activity factor for the multiplexed data stream, AF S , is AF S =1, irrespective of the transition probabilities for the two individual data streams.
Transition encoding is a technique that has been proposed in M. Anders, et al., “A Transition-Encoded Dynamic Bus Technique for High-Performance Interconnects,” IEEE Journal of Solid-State Circuits, Vol. 38, May 2003, pp. 709-714. This encoding technique XORs the input data to the line with the data value already transmitted on the line.
It can be shown that if the data is transition encoded after being serialized (multiplexed) using a simple XOR (exclusive OR), the resulting activity factor is 2AF 1 (1−AF 1 )+2AF 2 (1−AF 2 ).
It can also be shown that if the data is transition encoded before being serialized (multiplexed) using a simple XOR, the resulting activity factor is the sum of the individual line activity factors AF 1 +AF 2 .
From the equation for the average dynamic energy dissipation, E DYN , displayed in [0019], it is seen that the average dynamic energy is reduced if the activity factor is reduced. With this in mind, embodiments of the present invention are motivated by considering the various plots in FIG. 1 for the activity factor of a serialized data stream formed from two data streams. The x-axis in FIG. 1 is the sum of the activity factors for the two data streams, AF 1 +AF 2 , and the y-axis is the activity factor, AF S , for the serialized data stream formed from the two data streams. The different plots represent different schemes for combining the two data streams.
Plot 102 represents the activity factor AF S in which only serialization is performed. That is, the two data streams are multiplexed onto a single serial link without encoding. As discussed above, the activity factor for this scheme is simply AF S =1. Plot 104 is for the scheme in which serialization is followed by encoding. Plot 106 is for the scheme in which serialization encoding is performed before serialization (multiplexing).
From the plots in FIG. 1 , it is seen that if the activity factors of a line-pair (two data streams) are such that their sum is less than 1, then transition encoding is applied after serialization. This scheme is illustrated in FIG. 2 , where two data streams b 0 and b 1 are serialized by multiplexer (or serializer) 202 , and the resulting multiplexed data stream is then encoded by encoder 204 . Encoder 204 may be a simple XOR applied to the multiplexed data stream. More particularly, if one represents the multiplexed data stream (before encoding) by the time series x(n) and the encoded serialized data stream as x E (n), where n is a time index, then encoding the time series x(n) involves forming the XOR of x(n) and x E (n−1). That is, if the, then
x E ( n )= XOR{x ( n ) x E ( n− 1)}=( x ( n )∩ x E ( n− 1) )∪( x ( n ) ∩ x E ( n− 1)).
The interconnect in FIG. 2 is shown with various repeaters, indicated by label 206 . Decoder 208 performs the inverse of encoder 204 to recover the serialized data stream, and de-multiplexer (de-serializer) 210 recovers the two data streams b 0 and b 1 (assuming that such factors as noise, inter-symbol interference, etc., does not introduce errors.) For simplicity, a separate bus driver is not shown, but may be considered as part of encoder 204 . Similarly, a separate bus receiver is not shown, but may be considered as part of decoder 208 .
From the plots of FIG. 1 , it is seen that if the activity factors of a line-pair are such that their sum is greater than 1, then encoding is performed before serialization. This scheme is illustrated in FIG. 3 , where the two data streams are first each encoded by encoder 302 and encoder 304 , followed by serialization by multiplexer 306 . Upon reception, the serialized data stream is de-serialized by de-multiplexer 308 , and then the resulting data streams are decoded by decoder 310 and decoder 312 . Either scheme, either FIG. 2 or FIG. 3 , may be employed for the case in which the activity factors sum to 1.
The above description may be illustrated by the flow diagram of FIG. 4 . In block 402 , the activity factors for the two data streams are summed, or in practice, estimated, and in block 404 a determination is made as to whether this sum is less than 1. If the sum is less than 1, then the order of blocks 406 and 408 indicate that serialization is performed before encoding, whereas otherwise encoding is performed before serialization as indicated by the order of blocks 410 and 412 . The resulting serialized data stream is then transmitted over the bus, as indicated in block 414 .
The circuit diagrams indicated in FIGS. 2 and 3 may be combined into the circuit diagram of FIG. 5 , where encoders are programmable such that they either encode or simply pass their input signal through to their output port. Similar remarks apply to the decoders in FIG. 5 . For example, if the activity factors are known, estimated, or measured to sum to less than 1, then encoders 502 and 504 are set so that they pass their input through unchanged, and encoder 506 is set so that it encodes its input. If the activity factors are known, estimated, or measured to sum to greater than 1, then encoders 502 and 504 are set so that they encode, whereas encoder 506 is set so that it passes its input through unchanged. Similar remarks apply to the decoders.
In addition to employing the various schemes as indicated in the above drawings and discussed above, the dimensions of the serial links may be designated by assigning different line pitches p according to their activity factors, where p=w+s, where w is the interconnect width and s denotes the spacing between two adjacent interconnects. Conventional buses are usually designed with minimum width and minimum spacing to save metal area, resulting in interconnects having the same pitch, width, spacing, and hence the same line capacitance. By employing the embodiments as described above into the same bus area as a conventional bus, the available serial link pitch is greater than that of a conventional bus because there are now half the number of interconnects occupying the same area. Thus, if the activity factors of the bus lines are known a priori, greater line pitch may be allocated to those serial links having higher activity factors.
The increased line pitch results in reduced capacitance. Hence, the pitch of each serial link may be selected such that the sum of the pitches is equal to the available bus width, and such that the sum
∑ i AF ( i ) C T ( i )
is minimized, while maintaining the same conventional bus throughput. This may be illustrated by the flow diagram of FIG. 6 , where given the activity factors, block 602 chooses a set of pitches p(i) over the index i such that the sum
∑ i p ( i )
equals the available bus width. By choosing the set of pitches, the capacitances C T (i) may be calculated in block 604 . A criterion of goodness may be invoked in block 606 to determine if the sum
∑ i AF ( i ) C T ( i )
is minimized or is close to minimum. If further iterations are needed to reduce this sum, then a new set of pitches may be chosen in block 602 . Various numerical techniques, such as the method of steepest decent, for example, may be invoked to iterate on the set of chosen pitches. Eventually, a criterion of goodness may be satisfied by which the sum
∑ i AF ( i ) C T ( i )
does not change much for a new iterations, in which case the procedure indicated by the flow diagram of FIG. 6 stops, as indicated in 608 .
The design of a double-pumped serial link is relatively straightforward, and does not require an extra clock signal with double the system frequency because both edges of the system clock may be used. Furthermore, double-pumped serial links may also be used for multi-cycle buses by using intermediate double-edged trigger flip-flops, with the first stage containing the serializer and the last stage containing the de-serializer. It should also be noted that time borrowing may be applied to serial link buses in a manner similar to that of applying it to conventional static buses.
Embodiments of the present invention are expected to find applications to, but not necessarily limited to, computer systems. In particular, a microprocessor with one or more cores may utilize relatively long buses for one component of the microprocessor to communicate with another component. Such microprocessors may be part of a computer system, as illustrated in FIG. 7 . FIG. 7 illustrates a portion of a computer system employing microprocessor 702 , chipset 704 , and system memory 706 . Chipset 704 may comprise one or more chips, or may be integrated or partially integrated with microprocessor 702 . Chipset 704 handles various communication functions, including communication with microprocessor 702 and system memory 706 . Embodiments of the present invention may find applications in microprocessor 702 , chipset 704 , or both, as well as other components making up a computer system.
Various modifications may be made to the disclosed embodiments without departing from the scope of the invention as claimed below.
It is to be understood in these letters patent that the meaning of “A is connected to B”, where A or B may be, for example, a node or device terminal, is that A and B are connected to each other so that the voltage potentials of A and B are substantially equal to each other. For example, A and B may be connected by way of an interconnect. In integrated circuit technology, the interconnect may be exceedingly short, comparable to the device dimension itself. For example, the gates of two transistors may be connected to each other by a polysilicon or copper interconnect that is comparable to the gate length of the transistors. As another example, A and B may be connected to each other by a switch, such as a transmission gate, so that their respective voltage potentials are substantially equal to each other when the switch is ON.
It is also to be understood in these letters patent that the meaning of “A is coupled to B” is that either A and B are connected to each other as described above, or that, although A and B may not be connected to each other as described above, there is nevertheless a device or circuit that is connected to both A and B. This device or circuit may include active or passive circuit elements, where the passive circuit elements may be distributed or lumped-parameter in nature. For example, A may be connected to a circuit element that in turn is connected to B.
It is also to be understood in these letters patent that various circuit blocks, such as current mirrors, amplifiers, etc., may include switches so as to be switched in or out of a larger circuit, and yet such circuit blocks may still be considered connected to the larger circuit because the various switches may be considered as included in the circuit block.
Various mathematical relationships may be used to describe relationships among one or more quantities. For example, a mathematical relationship or mathematical transformation may express a relationship by which a quantity is derived from one or more other quantities by way of various mathematical operations, such as addition, subtraction, multiplication, division, etc. Or, a mathematical relationship may indicate that a quantity is larger, smaller, or equal to another quantity. These relationships and transformations are in practice not satisfied exactly, and should therefore be interpreted as “designed for” relationships and transformations. One of ordinary skill in the art may design various working embodiments to satisfy various mathematical relationships or transformations, but these relationships or transformations can only be met within the tolerances of the technology available to the practitioner.
Accordingly, in the following claims, it is to be understood that claimed mathematical relationships or transformations can in practice only be met within the tolerances or precision of the technology available to the practitioner, and that the scope of the claimed subject matter includes those embodiments that substantially satisfy the mathematical relationships or transformations so claimed.
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Embodiments of the present invention provide a bus architecture utilizing multiple-pumped serial links, and a combination of encoding and serialization to two data streams to transmit and receive a serialized data stream over a bus. The order in which encoding and serialization takes place depends upon the anticipated activity factors of the two data streams, and is chosen to reduce average energy dissipation. Other embodiments are described and claimed.
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BACKGROUND OF THE INVENTION
This invention relates a data transmission system wherein a plurality of transmission modules are connected in a multidrop manner.
It is well known that signal transmission may be effected utilizing building or house wiring or cable for power distribution. A typical example of a multidrop connection scheme is illustrated in FIG. 1, which includes a power distribution cable 1 and a plurality of transmission modules 2 for the transmission and receipt of data. The most serious problem of this kind of system is that in the event that any one of the transmission modules 2 is faulty in a hardware aspect while signals representative of transmission data continued to be supplied to the cable 1, the system becomes disabled as a whole and fails to send signals. In the case that a large number of the modules are installed, it is very difficult to determine which module is working improperly.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a data transmission system featuring the ability to check the transmission state at the level of individual modules through proper selection of code notation of signals. If the system detects a faulty module or modules it will inhibit only those faulty modules from sending signals thereby avoiding the breakdown of the system as a whole.
In a broad aspect of the present invention, there is provided a data transmission system including a plurality of transmission modules connected to a single cable in a multidrop manner, each of said transmission modules comprising means for generating codes which do not last at the same level for more than a given time even when the same data are transmitted continuously, means for monitoring the time where said codes remain at the same level, and means for considering the subject module as faulty and compelling the transmission state to a halt if the time the level remains constant exceeds a predetermined time.
The present invention therefore provides a very useful data transmission system having the plurality of transmission modules connected to a single cable in a multidrop manner, which system treats a specific module that has signals lasting at the same level for more than a given time except cable outputs, as involving a faulty condition and compels its transmission state to a halt, thus preventing only such a faulty module or modules from transmitting signals and avoiding breakdown of the whole system.
These and other aspects and advantages of the present invention will be more completely described below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a multidrop connection transmission system;
FIG. 2 is a time chart for explaining an example of an NRZ (Non Return to Zero) code notation;
FIG. 3 is a time chart showing a signal waveform of Manchester codes;
FIG. 4 is a time chart showing a typical signal waveform of respective combinations of Manchester codes;
FIG. 5 is a flow chart describing trouble-shooting in an embodiment of the present invention;
FIG. 6 is a time chart showing a typical level variation during signal transmission according to the embodiment of the present invention;
FIG. 7 is a block diagram of the embodiment of the present invention;
FIG. 8 is a detailed circuit diagram of a major portion of FIG. 7;
FIG. 9 is a time chart showing signal waveforms in the major portion as shown in FIG. 8;
FIG. 10 is a block diagram of another embodiment of the present invention; and
FIG. 11 is a block diagram showing details of a major portion of FIG. 10.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 2 to 11, there are illustrated a few embodiments of the present invention.
The simplest data format is a so-called NRZ (Non Return to Zero) in which the signal level corresponds to the data on a one-to-one basis. When data are transmitted in NRZ notation, a voltage corresponding to a piece of data is applied to a signal line over a predetermined time τ as seen in FIG. 2. In the example of FIG. 2, a data "1" is defined by a voltage V P and a data "0" by a voltage V M . Nevertheless, in the case that the same data is transmitted continuously in the NRZ notation, the level remains constant and unchanged. This fact results in great difficulties in seeing if correct data are transmitted or if any hardware trouble arises in the system. The above problem may be overcome, provided that data are not represented by voltage levels on a one-to-one basis but by changes in the voltage levels.
The above precondition is satisfied by Manchester codes as depicted in FIG. 3, for example. According to the Manchester code notiation, each bit time τ is divided into two half slots and a data "0" is defined by a combination of levels "1" and "0" in time sequence and a data "1" by a combination of levels "0" and "1" in time sequence (or vice versa). In no event there is any signal lasting at the same level for more than τ seconds for possible four combinations of data, as would be understood from FIG. 4. If any signal lasts at the same level for more than τ seconds in the above code system, it may be considered that a hardware problem has happened somewhere in the sytem as long as such erroneous signal is distinguished from a silence.
The code notation as defined above is adopted in transmission modules pursuant to the teachings of the present invention. Trouble-shooting procedures are described in a flow chart of FIG. 5. A reference time is selected to be longer than τ and preferably selected to be more than 2τ. If there is no variation in the level of the signal being transmitted for more than such reference time, then the remedy taken thereafter is to treat the subject transmission module as having a hardware problem, disconnect its level supplying section and indicate that the subject module is out of condition.
One way to determine whether the module is in the transmission state and to disconnect the level supplying section is discussed below. To make detection of a silence easy, levels other than V P and V M are used during a silence interval (typically, V P +V M /2). A typical example for implementing detection of abnormal transmission and forced disconnection is illustrated in FIG. 7.
In FIG. 7, there are shown a cable 1 for module-to-module signal transmission (also for power distribution), a disconnecting switch 21 for disconnecting the faulty transmission module or modules from the transmission cable during a silence interval or forced interruption of transmission and an AND gate 24 for controlling the switch 21. A transmission output section is denoted by 22 and whether the output section 22 is in the transmission state is determined by a signal TXSENSE. A transmission level setting section 23 outputs levels corresponding to outputs from the preceding code converter 25. The code converter 25 is adapted to convert NRZ data into a suitable code notation (the Manchester code or the like as described above). A data generation and control section 26 on one hand feeds the NRZ data to the code converter 25 and on the other hand feeds a transmission/disconnection signal TXENABLE to the AND gate 24. Another AND gate 27 is to permit monitoring of the transmission level by the signal TXSENSE only while the switch 21 is ON. A timer 28 is adapted for measuring the time that the signal remains at the same level. It is cleared with every variation in the level and keeps timer operation while the transmission level remains unchanged.
When the reference time is reached by the timer, its output TIMEOUT becomes true so that the output of the AND gate 24 is false and the switch 21 is OFF to bring transmission by the module to a stop. Since the data generation and control section 26 is usually implemented with a microcomputer or complicated hardware logic connection, this section more often causes a hardware trouble than the other sections in FIG. 7. In particular, when this is implemented with the microcomputer, it demands a special means to recover after a program sequence therein falls into disorder and the section gets out of control. To this end the signal TIMEOUT is applied as a RESET signal to the data generation and control section 26, with concurrent inhibition of level supply. Should the data control section return to its normal state with the signal RESET, the system is ready to re-start transmission. Unless the data control section recovers its normal state, the subject module is disabled and the system cannot transmit data to and from that module. However, in no event is the system broken down as a whole.
A simple and reliable way to generate the signal TXSENSE is to derive a power source current from the final stage. For this reason the transmission output section 22 of FIG. 7 is of an emitter follower configuration as shown in FIG. 8 (when V P <0, V M =0).
In FIG. 8, the transmission output section 22 includes an output stage emitter follower 31, a detector circuit 32 for deciding by current detection if a transistor T 1 is ON when IN=V P , and a detector circuit 33 decides by current detection if a transistor T 2 is ON when IN=0. The signal TXSENSE is derived from an OR gate 34 responsive to the outputs of the two detector circuits 32 and 33. The detection levels may be optionally selected through the use of R S1 and R S2 with the resistances determined by the following definition.
I.sub.SP ≦R.sub.S1.Vbe.sub.P, I.sub.SM ≦R.sub.S2 Vbe.sub.M (1)
Vbe P =base-emitter voltage of T 3 ˜0.7 V
Vbe M =base-emitter voltage of T 4 ˜0.7 V
Various signals occurring in the circuit of FIG. 8 in operation are depicted in FIG. 9. The output of the circuit 32 is A and the output of the circuit 33 is B. The charging of a capacitor C via a resistor R starts when a transistor Tr 3 or Tr 4 in the detector circuits is turned ON, and the output appears with a time delay T determined as a function of the CR time constant and the threshold voltage Vth of the OR gate 34 as follows: ##EQU1## The potential at the cpacitor C drops to zero immediately after the transistor Tr 3 or Tr 4 is turned OFF. In the illustrated example, the timer 28 of FIG. 7 is made up by a CR integration circuit. Whenever the level of the signal under transmission changes, the signal TXSENSE never fails to fall to zero for the time T. This results in initializing the timer to zero and re-starting time measurement. As already described, if the signal TXSENSE lasts for more than the reference time, the signal TIMEOUT is developed to force the transmission state to a halt.
It is obvious that the present invention is equally applicable to transmission systems that use a carrier. Another embodiment of the present invention using AM modulation is shown in FIG. 10, with a simpler circuit than the previous embodiment of FIG. 7. The components 1, 22, 24-26 are similar to those in FIG. 7. A transmission/disconnection switch 21' also serves to determine whether to apply the carrier. A carrier oscillator is denoted by 41. FIG. 11 shows a circuit corresponding to that in FIG. 8, wherein a CR integration circuit 42 is equivalent to the timer 28 of FIG. 7. The CR time constant of the integration circuit 42 is selected within a range from T to 2τ. The circuit 33 in FIG. 8 is not necessary because of the need for only decision as to whether to apply the carrier.
The invention thus being described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications are intended to be included within the scope of the following claims.
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A very useful data transmission system having a plurality of transmission modules connected to a single cable in a multidrop manner is disclosed herein. The system features its ability to check the transmission state at the level of individual modules through use of a proper code notation (typically, Manchester code). The system detects a specific module with proper signals lasting at the same level for more than a given time, except cable outputs, and treats it as involving a faulty condition and compels the transmission state to a halt, thus preventing only the faulty module or modules from transmitting signals thereby avoiding breakdown of the whole system.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Divisional of application Ser. No. 11/474,313 filed on Jun. 26, 2006, which is a non-provisional application that claims the benefit of French Application No. 05 51825 filed on Jun. 29, 2005 and U.S. Provisional Application No. 60/701,063 filed on Jul. 21, 2005. The disclosures of the prior applications are hereby incorporated by reference herein in their entireties.
[0002] The present invention relates to applicators for applying a cosmetic or a care product, for example, makeup or a skin care product, for example, a composition such as a nail varnish. The present invention also relates to packaging and applicator devices including such applicators.
BACKGROUND
[0003] Numerous applicators comprise an applicator member, for example, a bundle of bristles, fastened to an end of a stem for applying composition to a surface of the human body, for example, skin, lips, hair, or nails, for example, fingernails or toenails.
[0004] French patent applications FR-A-2 722 380 and FR-A-2 722 381 disclose applicators having a stem that includes flexibility that is close to a flexibility of the applicator member, the stem being, over a large portion of a length thereof, of smaller cross-section than a remainder of the stem.
[0005] Patent application EP-A-1 504 691 discloses an applicator including a stem having a flexible portion with shape memory, and a bottom half that is substantially non-flexible.
SUMMARY
[0006] Stems such as those disclosed in FR-A-2 722 380 and FR-A-2 722 381 may be molded. It may be necessary for each type of applicator to modify the length of the portion of smallest cross-section, thereby requiring several molds to be made, correspondingly resulting in relatively high costs.
[0007] Fastening the applicator member in a flexible stem, such as disclosed in EP-A-1 504 691, for example, by implanting a bundle of bristles, a flocked endpiece, felt, or a foam in the stem, may be made more difficult by the fact that the stem may bend easily. To avoid that problem, it is possible to hold the stem during the fastening operation, but that complicates assembly.
[0008] There exists a need to have an applicator that makes it possible to apply makeup accurately, while being comfortable to use.
[0009] There also exists a need to make it easier to manufacture an applicator including a stem that has a desired deformability characteristics, while avoiding the use of costly molds.
[0010] There also exists a need to make it possible to implant the applicator member easily into the stem.
[0011] Exemplary embodiments of the invention seek, for example, to satisfy such needs, in full or in part.
[0012] Exemplary embodiments of the invention may achieve one or more of such advantages by providing an applicator for applying a cosmetic or a skin care product, the applicator comprising: a stem including at least one stamped portion comprising a joint; and an applicator member disposed at a first end of the stem.
[0013] The term “stamped portion” should be understood as a portion of the stem that is deformed hot or cold by being subjected to pressure of a die. The stem of the applicator may advantageously be deformed once the stem has been molded and removed from the mold.
[0014] It may thus be possible to use standard stems without it being necessary to make specific molds.
[0015] The material of the stem may creep under the pressure of the die. Where appropriate or desired, the die may be configured in such a manner as to orientate deformation generated by the creep so as to form a portion in relief, which may make it possible to regulate flow of composition along the stem.
[0016] The stamped portion may substantially maintain the deformation acquired during stamping, without returning to an initial shape thereof during the lifetime of the applicator.
[0017] During stamping, depending on the flexibility desired, and on the kind of stem, a thickness of the stem may be reduced by at least 50%, for example, or even by at least 97%, for example, in a direction in which the pressure is applied to cause the material to creep.
[0018] The thickness of the stem prior to creep may be 3.5 millimeters (mm), and a minimum thickness of the stamped portion may not be greater than 0.1 mm, for example, such exemplary values in no way limiting the invention.
[0019] The joint may make it possible to create a hinge and/or a zone of weakness that enables two adjacent stem segments to change orientation relative to each other. The joint-forming stamped portion may not serve to fasten the applicator member on the stem.
[0020] Exemplary embodiments may make it possible to create a wide variety of stems including at least one joint, without the need to manufacture specific molds. Thus, at least during use, the stem may be given a non-rectilinear shape.
[0021] Exemplary embodiments may make it possible to reduce pressure of the applicator member on the treated surface by the stem deforming. The applicator may enable a user to have a better application technique that is more flexible, more comfortable, and/or more accurate.
[0022] The stem may include at least one bead resulting from stamping. The stamped bead may form a lateral projection on the stem.
[0023] The stem may include at least two stamped portions, indeed three or even more, each portion comprising a respective joint. The stamped portions may be made simultaneously with a common die, or successively by displacing the stem relative to the die, for example.
[0024] The stamped portion need not be circularly symmetrical, so as to encourage the creation of a joint about a predefined hinge axis. For example, the stamped portion may comprise a bridge of material including a flat shape in cross-section.
[0025] The applicator may be symmetrical about a mid-plane, for example, a plane that is perpendicular to a hinge axis defined by a stamped portion. At least one stamped portion may be situated in a bottom half of the stem.
[0026] The stem may include at least one stamped portion including at least one opening, for example, at least one opening disposed between two branches interconnecting stem segments that are situated on either side of the stamped portion. For example, such an opening may be formed during the stamping operation, by being cut out.
[0027] A bottom wall of the stamped portion may extend substantially perpendicularly to the longitudinal axis of the stem. In another exemplary embodiment, the bottom wall of at least one stamped portion may extend non-perpendicularly to the longitudinal axis of the stem. The orientation of the stamped portion(s) may be selected as a function of a way in which it is desired that the stem will deform. For example, the stem may include at least two stamped portions that extend along lines that are not parallel.
[0028] The stem may include at least two stamped portions of different shapes, for example, because the portions may result from applying two dies of different shapes, or from applying a common die with different pressures and/or on regions of the stem including different initial shapes and/or orientations, for example.
[0029] The stem may include at least two stamped portions of a same shape, for example, resulting from the use of a common die.
[0030] The stem may include at least two stamped portions including a same profile when the stem is observed in a direction that is perpendicular to the longitudinal axis thereof. The two stamped portions may optionally be symmetrical to each other about a plane, for example, a plane extending perpendicularly to the longitudinal axis of the stem.
[0031] At least one stamped portion may include at least one projection of material that may be situated on at least one flank of a stem segment that may be connected to the stamped portion. The projection may be formed during the stamping operation, for example, by giving a corresponding shape to the die. The projection may correspond to a portion of the material that is displaced by creep. The stem may include at least two flanks that are situated on either side of the stamped portion, sloping relative to the longitudinal axis of the stem, and indeed substantially perpendicular to the stem. Where appropriate or desired, the shape of the stamped portion may be selected in such a manner as to define a maximum pivot angle of adjacent stem segments, by one flank coming into abutment against the other. The stamped portion may thus be configured to limit a degree to which the stem segments that are situated on either side of the stamped portion may pivot relative to each other.
[0032] The stamped portion may extend over various lengths, depending on a degree to which the hinge is to be localized, for example. The length of the stamped portion may be up to 25 mm, for example, although a shorter length is preferred in most applications.
[0033] At least one stamped portion may include a longitudinal cross-section of shape that may be generally rectangular, triangular, or even circular, oval, or elliptical, at least in part, depending on a shape of the die used, for example.
[0034] The shape of the cross-section of the stem may be selected from: circular, non-circular, oblong, oval, elliptical, polygonal, square, rectangular, kidney-shaped, notched, or star-shaped, and with one or more grooves, where appropriate or desired. Prior to stamping, the stem may optionally include a cross-section that is constant, and may be solid or hollow over an entire length thereof or in portions, for example. For example, the stem may be solid in a joint-forming stamped portion, and may be hollow elsewhere. For example, a diameter of the stem may be less than about 10 mm.
[0035] The stem may be made of a thermoplastic material, for example, at least one of the materials selected from the group constituted by: high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear polyethylene (linear PE), polypropylene (PP), polyoxymethylene (POM), polyamide (PA), polyethylene (PET), and polybutyl terephthalate (PBT), or a mixture of such materials. Linear PE may provide better resistance to pressure and forces exerted during stamping.
[0036] The applicator member may comprise at least one of: a bundle of bristles, for example, comprising a paint brush; a comb; a brush; felt; a flocked coating; and a foam. For example, the applicator member may comprise a flocked endpiece, for example, a flocked tip.
[0037] In exemplary embodiments in which the applicator member comprises a bundle of bristles, at least two bristles of the bundle may each include a respective periodic pattern including at least one wave, with at least two periodic patterns being different. The expression “periodic pattern” refers to a portion of the bristle that is reproduced substantially periodically along the bristle.
[0038] The bundle of bristles may comprise at least two bristles of lengths, and/or diameters, and/or cross-sections, and/or materials that are different.
[0039] The bristles may be made of synthetic material, for example, a thermoplastic material, for example, thermoplastic elastomer. At least one bristle may be made of a natural material.
[0040] The bristles may include cross-sections that are solid or hollow and optionally circular. The cross-sections need not be constant along the bristles, for example, alternating between cross-sections of relatively large diameter and cross-sections of relatively small diameter. The bristles may possibly be coated in flocking.
[0041] Over an entire length thereof, or over a fraction only of the length thereof, the bristles may also include a filler, for example, of a magnetic compound, or a moisture-absorbing compound, or a compound for creating roughness on a surface of the bristle, or even for favoring sliding. The filler may be distributed in such a manner as to create a periodic pattern.
[0042] The bundle of bristles may be fastened in a housing formed at the first end of the stem. The bristles may be configured, for example, to be fastened in the housing by adhesive, stapling, stamping the stem, heat sealing, and/or injection molding. The housing may include an oblong cross-section that is elongate along a long axis, so as to form a flat bundle. For example, the long axis of the cross-section of the housing may be substantially parallel to a hinge axis defined by a stamped portion.
[0043] The housing may include a cross-section that decreases toward an end wall thereof, with a degree to which the cross-section decreases depending on a degree to which the bristles are to diverge. The end wall of the housing may include a recess in which the bristles are fastened, and which opens into a portion of the housing that flares toward the opening of the housing. Such a flared portion may enable the bristles to spread out more easily from each other so as to give the bundle a wide shape.
[0044] The housing may be configured in such a manner that the bristles extend from the housing over a distance that may be greater than a depth of the housing.
[0045] In another exemplary embodiment, the stem and the applicator member may be made as a single part, for example, by injection-molding or by dual-injection-molding.
[0046] The stem may also be injection molded on the applicator member.
[0047] The applicator may include a handle fastened to a second end of the stem, remote from the first end. The handle of the applicator may also comprise a closure cap configured to close a receptacle containing the composition to be applied.
[0048] At a second end thereof, remote from the first end, the stem may include a fastener member configured to be fastened to the handle. The fastener member may include an endpiece configured to be force-fitted and/or snap-fastened in the handle. The endpiece may include a tubular skirt with a collar at a base thereof. The collar may be configured to come to bear against a top surface of a neck of a receptacle containing the composition, ensuring that the receptacle is closed in a leaktight manner, for example. In another exemplary embodiment, the receptacle may be closed in a leaktight manner using other means.
[0049] The handle may include fastener means for fastening to a receptacle, for example, a thread.
[0050] A shape of the handle need not be circularly symmetrical, thereby favoring a predefined orientation for holding the applicator. The handle may include at least one reception zone configured to receive a finger, for example, a flat or an indent that extends substantially parallel to a hinge axis defined by a stamped portion.
[0051] Independently or in combination with the above, exemplary embodiments of the invention may provide a packaging and applicator device for applying a cosmetic composition comprising an applicator as defined above, and a receptacle containing a composition to be applied.
[0052] The composition may be a nail composition, for example, a nail varnish or a care product for the nails. In another exemplary embodiment, the composition may be an eyeliner, an eyeshadow, or a lip composition, for example, a lipstick or a lipgloss.
[0053] The device may further include a wiper member configured to wipe the applicator member while the applicator member is being removed from the receptacle.
[0054] The device may advantageously include means for ensuring that the receptacle is closed in a leaktight manner.
[0055] Independently or in combination with the above, exemplary embodiments of the invention may provide a method of manufacturing an applicator as defined above. The method may comprise stamping at least one portion of a stem including an applicator member, so as to form at least one joint.
[0056] In exemplary embodiments, the portion of the stem may be stamped at ambient temperature, i.e., cold stamped, without special heating. In another exemplary embodiment, the portion of the stem may be hot stamped.
[0057] In exemplary embodiments, a plurality of stamped portions may be formed simultaneously. In another exemplary embodiment, a plurality of stamped portions of the stem may be stamped successively, for example, using a same die, with relative displacement of the stem and the die between the stamping operations.
[0058] Independently or in combination with the above, exemplary embodiments of the invention may provide a manufacturing machine that is configured to receive a stem, and that includes a die configured to stamp the stem so as to form a joint on the stem.
[0059] The stem may be provided with an applicator member prior to the stamping operation. The die may include a housing that is configured to receive and hold the stem during the stamping operation. Both of the jaws of the die may be movable, or one of them may be stationary.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] Various details of the present invention may will be better understood on reading the following detailed description of non-limiting embodiments, and on examining the accompanying drawings, in which:
[0061] FIG. 1 is a diagrammatic longitudinal view in axial cross-section illustrating an exemplary device for applying a composition to nails;
[0062] FIGS. 2 and 3 are fragmentary diagrams in axial cross-section illustrating the stem and the applicator member of the device of FIG. 1 ;
[0063] FIG. 4 is a fragmentary diagram in axial cross-section illustrating the applicator of FIG. 1 in use;
[0064] FIG. 5 is a larger-scale view illustrating a detail of another exemplary embodiment of the stem;
[0065] FIG. 6 is a fragmentary side view of the applicator of FIG. 5 ;
[0066] FIG. 7 is a view similar to FIG. 2 illustrating another exemplary embodiment;
[0067] FIGS. 8 to 14 and 16 to 21 are diagrammatic views similar to FIG. 5 illustrating exemplary embodiments of the stem;
[0068] FIG. 15 is a longitudinal cross-section taken along XV-XV in FIG. 14 ;
[0069] FIG. 22 is a diagrammatic and fragmentary perspective view of another exemplary embodiment of the stem;
[0070] FIGS. 23 to 31 are exemplary stem cross-sections taken at the applicator member;
[0071] FIGS. 32 to 36 are diagrams illustrating exemplary embodiments of applicator members;
[0072] FIGS. 37 to 43 are diagrams illustrating exemplary cross-sections of bristles that are suitable for forming the applicator member;
[0073] FIG. 44 is a diagrammatic and fragmentary view in longitudinal cross-section illustrating another exemplary embodiment of the applicator member;
[0074] FIG. 45 illustrates another exemplary embodiment of an applicator member;
[0075] FIG. 46 is a diagram in perspective illustrating another exemplary embodiment of the applicator;
[0076] FIG. 47 is a fragmentary longitudinal cross-section illustrating another exemplary embodiment; and
[0077] FIGS. 48 to 51 illustrate exemplary dies that make it possible to deform the stem of an applicator.
DETAILED DESCRIPTION OF EMBODIMENTS
[0078] FIG. 1 illustrates a packaging and applicator device 1 comprising a receptacle 2 containing a composition P for application, for example, a nail varnish, and an applicator 3 comprising a stem 4 that carries, at a first end 5 , an applicator member 6 , and that may be engaged, at a second end 8 , in a handle 9 which, in the exemplary embodiment, also constitutes a closure cap of the receptacle 2 , and may be configured to be screwed onto the receptacle.
[0079] The stem 4 of the applicator 3 is illustrated in isolation in FIGS. 2 and 3 .
[0080] In exemplary embodiments, the stem 4 may include at least one stamped portion 10 comprising a joint, and specifically two such stamped portions 10 in the exemplary embodiment.
[0081] In the exemplary embodiment, each stamped portion may include two beads 11 on two opposite sides of the stem. The stem 4 may thus be widened in a first direction of observation that is perpendicular to a longitudinal axis thereof, as illustrated in FIG. 2 .
[0082] In a second direction of observation that is perpendicular to the longitudinal axis X and to the first direction, the stem 4 may be made narrower, as illustrated in FIG. 3 , and may form a joint that encourages the stem 4 to deform about a hinge axis W.
[0083] Thus, each stamped portion 10 may not be circularly symmetrical, and may include a smaller flat cross-section of major axis parallel to the hinge axis W.
[0084] Nevertheless, each stamped portion 10 may be substantially symmetrical about a mid-plane that contains the longitudinal axis X of the stem, and that is perpendicular to the corresponding hinge axis W.
[0085] As illustrated, at least one stamped portion 10 may be situated in a bottom half of the stem 4 , in such a manner as to encourage the stem to deform in a proximity of the applicator member 6 , so as to provide flexibility during application.
[0086] At least one stamped portion may also be situated in proximity to the end 8 of the stem, for example, in a top half of the stem.
[0087] In the exemplary embodiment, the applicator member 6 may comprise a tuft of bristles in such a manner as to form a brush. At the first end 5 , the stem 4 may include a housing 23 inside which the bristles are fastened, for example, by stapling, adhesive, heat sealing, and/or injection molding. For example, the housing 23 may include an opening of rectangular cross-section, of elongate shape along a major axis that is perpendicular to the longitudinal axis X of the stem 4 , and that is parallel to the hinge axes W.
[0088] As illustrated in FIGS. 2 and 3 , the housing 23 may include a cross-section that decreases toward the end wall 24 of the housing. The bristles may spread out when the brush is applied to the nail, as illustrated in FIG. 4 . Depending on a shape given to the housing 23 , a wider or narrower bundle of bristles may be obtained.
[0089] At the second end 8 , the stem 4 may include an endpiece configured to be fastened in the handle 9 . The endpiece may comprise a tubular skirt 27 , and a collar 29 that may be formed at a base thereof that is configured to come to bear against a top edge of the neck 28 when the applicator is in place on the receptacle 2 . Below the collar 29 , the stem 4 may include a cone-shaped portion 30 that may be capable of contributing to closing the receptacle 2 in a leaktight manner when the applicator 3 is in place on the receptacle.
[0090] Naturally, the stem 4 may be fastened onto the handle 9 in some other way, and, for example, may be made integrally, i.e., monolithically, with the handle, or fastened to the handle by adhesive, heat sealing, or force fitting, or by a fastener element fitted on the handle and/or on the stem.
[0091] For example, the stem 4 may be made of a thermoplastic material such as a polyolefin, for example, polyethylene or polypropylene, or may be made of other plastics materials such as POM, PA, PET, and/or PBT.
[0092] During use, at least one stamped portion 10 may make it possible for adjacent stem segments to pivot relative to each other, as illustrated in FIG. 4 , thereby making it possible to obtain smoother application, for example. Where appropriate or desired, a shape of each stamped portion 10 may be selected in such a manner as to limit a pivot angle of adjacent segments. For example, the pivot angle may be determined by a length l of the stamped portion, measured between the adjacent segments, as illustrated in FIG. 3 , and by a shape of the flanks facing the segments.
[0093] When the user ceases to press the applicator member 6 against the surface to be treated, each stamped portion 10 may spread out elastically to a greater or lesser extent depending on the material used to make the stem, so as to return the first end 5 and the applicator member 6 into alignment with the second end 8 .
[0094] In another exemplary embodiment, the stem need not return to its initial shape after application.
[0095] In the exemplary embodiment in FIGS. 1 to 4 , the stem 4 may include two stamped portions 10 . It is contemplated that the stem 4 may include a different number of stamped portions, for example, a single portion, as illustrated in FIG. 7 , or more portions, as illustrated in FIGS. 5 and 6 .
[0096] In exemplary embodiments in which the stem 4 includes a large number of stamped portions, the stem 4 may be deformed almost continuously during application, with each stem segment adjacent to a stamped portion sloping by an angle that may be relatively small relative to the adjacent segment(s), for example.
[0097] A stamped portion 10 may include a longitudinal cross-section of substantially triangular shape over at least a fraction of a length thereof, as illustrated in FIG. 8 , thereby making it possible, depending on the angle formed between the facing flanks of the adjacent stem segments, to define a maximum pivot angle. In another exemplary embodiment, the stamped portion 10 may include a longitudinal cross-section of substantially rectangular or trapezoidal shape, as illustrated in FIG. 9 , thereby enabling pivoting to be greater.
[0098] A length a of a bridge of material 13 of a stamped portion 10 , measured along the longitudinal axis of the stem, may lie in a range of about 0.1 mm to about 25 mm, for example.
[0099] A minimum thickness b of the bridge of material 13 of a stamped portion 10 may be 0.1 mm, for example.
[0100] A diameter of a circle in which the cross-section of the stem is inscribed prior to stamping may not be greater than about 10 mm, for example.
[0101] A stamped portion 10 may comprise a bridge of material 13 that connects two adjacent stem segments 14 , 15 , and that may be provided with at least one notch 18 , as illustrated in FIG. 10 , so as to make pivoting even easier. The notch 18 may advantageously be formed during stamping.
[0102] For example, the bridge of material 13 may lie on the longitudinal axis of the stem X, as illustrated in FIGS. 8 to 10 , In another exemplary embodiment, the bridge of material 13 may be offset relative to the longitudinal axis X, as illustrated in FIG. 11 .
[0103] Still in another exemplary embodiment, the bridge of material 13 may include one side lying substantially in line with the segments 14 and 15 that the bridge of material 13 connects, as illustrated in FIG. 12 , and may possibly include a small projection on a side remote from a recess resulting from the stamping, as illustrated in FIG. 13 .
[0104] The bridge of material 13 may be solid, or, in another exemplary embodiment, may include an opening formed by being cut out during the stamping operation.
[0105] For example, FIGS. 14 and 15 illustrate a stem including at least one stamped portion 10 including at least one opening 16 , disposed between two branches 17 interconnecting the segments 14 and 15 . The branches may optionally be rectilinear, or optionally concentric.
[0106] The stem 4 may include stamped portions that are all identical, for example, including a same profile when the stem is observed perpendicularly to the longitudinal axis X, or may include stamped portions including the same profile in a first direction that is perpendicular to the longitudinal axis X, and different profiles when observed in a second direction that is perpendicular to the longitudinal axis X, and that is also perpendicular to the first direction, for example. Still in another exemplary embodiment, the stem may include at least two stamped portions including a different profile whatever the direction in which the stem is observed.
[0107] The stem may include at least two stamped portions 10 including different shapes, as illustrated in FIG. 16 , with one stamped portion comprising a bridge of material 13 that may be longer than the other. For example, this may make it possible to further control the way in which the segments tend to pivot relative to each other during use.
[0108] In all of the embodiments described above, the stamped portions illustrated may be symmetrical about a mid-plane of the portion, and may be perpendicular to the longitudinal axis X of the stem. It is contemplated, however, that this may be otherwise.
[0109] For example, FIGS. 17 to 19 illustrate exemplary embodiments of stamped portions that extend in a non-symmetrical manner about a plane that is perpendicular to the longitudinal axis X of the stem.
[0110] In the exemplary embodiment in FIG. 17 , the stamped portion may define a hinge axis W that is not perpendicular to the longitudinal axis X of the adjacent stem segment.
[0111] In the exemplary embodiment in FIG. 18 , the stamped portion may be substantially trapezoidal, comprising two asymmetric beads 11 disposed on either side of the stem.
[0112] In the exemplary embodiment in FIG. 19 , the stem 4 may comprise two stamped portions 10 that extend obliquely while being symmetrical relative to each other about a plane that is perpendicular to the longitudinal axis X of the stem.
[0113] In the exemplary embodiments described above, the bottom wall of the stamped portions may extend along a rectilinear line, for example, that is perpendicular to the longitudinal axis of the stem. However, it is contemplated that this may be otherwise. For example, FIGS. 20 and 21 illustrate exemplary embodiments of bent stamped portions.
[0114] At least one stamped portion 10 may include at least one projection of material that is situated on at least one of the flanks of the adjacent stem segments.
[0115] For example, FIG. 22 illustrates an exemplary stem 4 including a stamped portion 10 interconnecting two segments 14 and 15 of the stem that include, on respective flanks 20 thereof, two projections of material 19 that are situated on either side of the bridge of material 13 . Where appropriate or desired, the projections may serve to limit the degree to which one segment pivots relative to the other, and/or may act on a flow of composition along the stem during application.
[0116] The first end 5 of the stem 4 may include different cross-sections at the housing 23 configured to receive the applicator member 6 .
[0117] FIGS. 23 to 31 illustrate various exemplary cross-sections, amongst others. For example, the cross-section may be circular as illustrated in FIG. 23 , oblong as illustrated in FIG. 24 , for example, oval or elliptical, polygonal as illustrated in FIGS. 25 and 26 , for example, square or rectangular, kidney-shaped as illustrated in FIG. 27 , star-shaped as illustrated in FIG. 28 , or notched as illustrated in FIG. 29 .
[0118] The stem 4 may include at least one longitudinal groove 30 opening level with a middle of a long side of the housing containing the bristles, for example, as illustrated in FIGS. 30 and 31 . In the exemplary embodiment in FIG. 31 , the cross-section of the stem may be coaxial about the cross-section of the housing, and the thickness of the stem may be substantially constant over an entire periphery of the housing.
[0119] The bristles of the applicator member 6 may be of a very wide variety of kinds. For example, bristles may be used that include one of the cross-sections illustrated in FIGS. 37 to 43 , for example, a solid cross-section of circular outline as illustrated in FIG. 37 , a hollow cross-section, for example, of circular outline, as illustrated in FIG. 38 , a polygonal cross-section, for example, square as illustrated in FIG. 39 , triangular as illustrated in FIG. 40 , rectangular as illustrated in FIG. 41 , or even an oblong cross-section, for example, of elliptical outline as illustrated in FIG. 42 . The bristles may also include at least one capillary channel, as illustrated in FIG. 43 .
[0120] The bundle of bristles may comprise a mixture of kinds of bristle, as indicated above.
[0121] The bundle of bristles 6 may be given any shape, for example, with the bundle being trimmed while the bristles are in place on the stem. Free ends of the bristles may be trimmed in such a manner that the end of the applicator is rectilinear as illustrated in FIG. 32 , being perpendicular to the axis of the stem 4 , or including a concave curved shape as illustrated in FIG. 33 , a convex shape as illustrated in FIG. 34 , a chamfered shape as illustrated in FIG. 35 , or even trimmed to a pointed shape as illustrated in FIG. 36 .
[0122] Naturally, the invention is not limited to an applicator member 6 constituted by a bundle of bristles. For example, the applicator member may comprise a flocked endpiece as illustrated in FIG. 45 , or a flocked tip as illustrated in FIG. 44 . For example, the flocked tip may be configured to apply composition to skin, lips, hair, or nails, for example, lips, eyelids, or nails.
[0123] The applicator member 6 may also comprise any other applicator member such as a foam, a brush, felt, a comb, or an applicator including capillarity, for example, as a function of the kind of composition and the surface to be treated. Further, the applicator member 6 may possibly be made integrally, i.e., monolithically, with the first end 5 of the stem 4 , or fitted therein.
[0124] In exemplary embodiments in which at least one stamped portion 10 is made with a cross-section that is not circularly symmetrical, thus giving the stem 4 at least one preferred direction of deformation about a hinge axis W, the handle may be made with a shape that causes the user to hold the handle in a predetermined manner, in association with the orientation of the cross-section of the stamped portion 10 .
[0125] For example, the handle may include, on two sides that are remote from each other, recesses 33 or flats that serve to receive the fingers of the user, as illustrated in FIG. 46 .
[0126] The stamped portion(s) 10 and the handle may include generally flat shapes along a common plane that is substantially parallel to at least one of the hinge axes W, the stem 4 being able to deform perpendicularly to the plane.
[0127] In the exemplary embodiment in FIG. 1 , the device may not include a wiper member, and the applicator member 6 may, for example, be wiped on the neck 28 of the receptacle 2 while the applicator 3 is being removed from the receptacle.
[0128] In another exemplary embodiment, and as illustrated in FIG. 47 , the device may include a wiper member 34 disposed in the neck 28 of the receptacle. For example, the wiper member 34 may include an orifice, of diameter substantially equal to a diameter of the stem 4 , through which the applicator member 6 may pass.
[0129] The exemplary applicators described above may be manufactured by a die 40 comprising two jaws 41 and 42 that are movable relative to each other, and that are configured to move toward each other so as to stamp the stem, as illustrated in FIG. 48 .
[0130] FIG. 48 illustrates the stem received in the bottom jaw 42 , which may be stationary and includes a recess 43 . For example, the top jaw 41 may include a projection 44 including a profile that is to be hollowed out of the stem, as illustrated diagrammatically in FIG. 49 .
[0131] In the exemplary embodiment in FIGS. 48 and 49 , the zone of the bottom jaw 42 on which the movable jaw 41 comes to bear may be planar. In another exemplary embodiment, the jaw 42 may also include a projection 44 , as illustrated in FIG. 50 . Still in another exemplary embodiment, the jaws 41 and 42 may be configured to give the stem a non-rectilinear shape during stamping. For example, and as illustrated in FIG. 51 , the jaws 41 and 42 may be of generally curved shape, with one being concave and the other being convex.
[0132] The stem may already be provided with the applicator member during the stamping operation. The applicator member may thus be put into place more easily on a stem that is straight and relatively rigid.
[0133] The invention is not limited to the exemplary embodiments described above. For example, characteristics of the various embodiments may be combined with one another.
[0134] The expression “comprising a” should be understood as being synonymous with “comprising at least one”, unless specified to the contrary.
[0135] Although various details of the present invention herein have been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention.
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An applicator for applying a cosmetic or a skin care product may include a stem including at least one stamped portion forming a joint, and an applicator member disposed at a first end of the stem.
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FIELD OF THE INVENTION
The invention relates to the handling of printed products, for example newspapers, which are being fed in a continuous stream. In particular, the invention relates to a device for ensuring that the stream-fed products are regularly spaced.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a device which equalizes the spacing of printed products that are fed in a continuous stream.
According to the invention such a device is characterized in that a multiplicity of spacers are provided which are guided in a freely movable manner towards and then parallel to the stream-feed transport path and each of which has a driving stop which, in the region of the portion of the spacer guide which is parallel to the stream feed, engages in the path of movement of the leading edges of the printed products so that each of the spacers is driven by a printed product, while at a distance from the beginning of the aforesaid portion of the guide a brake device is provided which acts on the spacers to ensure that the spacers run on to one another.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are illustrated diagrammatically in the accompanying drawings, in which:
FIG. 1 is a side view of an exemplary device according to the invention,
FIG. 2 shows on a larger sacle the part of the device which is on the left in FIG. 1, but with modified stops,
FIG. 3 shows on a larger scale a slightly modified construction of the part of the device which is on the right in FIG. 1,
FIG. 4 is a view from above of a spacer in the position of readiness,
FIG. 5 is a side view of the spacer shown in FIG. 4,
FIG. 6 a front view of the spacer shown in FIGS. 4 and 5, viewed from the direction of the arrow P in FIG. 4,
FIG. 7 shows in perspective a modified construction of the spacer,
FIG. 8 is a view from above of the spacer shown in FIG. 7,
FIG. 9 a side view of the spacer of FIG. 8, and
FIG. 10 a front view of the spacer of FIG. 8.
DESCRIPTION OF PREFERRED EMBODIMENTS
As shown in FIG. 1, the stream feed formation given the general designation 1 is guided on conveyor belts 2, 3, and 4, which together form the transport path of the stream feed formation 1. It is convenient for the conveyor belt 3 to run at a higher speed than the belts 2 and 4, while however it may have a conveyor surface with lower friction than the other belts. The purpose of these arrangements will be explained in detail later on.
In the region of the conveyor belt 2 are disposed rollers 5 and 6 which are associated with one another and which together form a nip 7 through which the stream 1 passes. Because the roller 5 is disposed at a higher level than the conveyor surface of the belt 2, the leading edge -- as indicated at 8 -- of the stream-fed printed products, which in the present case are newspapers 9, is lifted until this edge comes to lie on a slide bar 10 and in accordance with the movement of the stream is guided while lying on the said bar. As indicated at 11, the slide bar 10 is mounted on a machine frame (not shown), together with two guide bars 12 which are parallel to one another and which extend side by side and spaced apart parallel to the transport path 2, 3, 4, their other ends likewise being fastened at 13 to the machine frame. According to this arrangement, only one of the guide bars 12, which in the present case have a circular profile, can be seen in FIG. 3.
A magazine 15 is fastened by means of a mounting 14 on the guide bars and, as can be seen in FIG. 4, has a pair of angle-bars 16 and a pair of hollow bars 17, which together form a vertical guide passage 18. In FIG. 1, only one of the angle bars 16 and one of the hollow bars 17 can be seen, whereas FIG. 4 shows the entire arrangement.
A stack 19 of spacers 20 lying one on the other is disposed in the magazine, the lowermost spacer lying on the guide bars 12. In order to enable this arrangement to be better understood and in particular to explain the construction of the spacers, reference will here first also be made to FIGS. 4, 5, and 6. It can be seen above all from FIG. 4 that the spacers 20 are in the form of a U-shaped bow, consisting of a web 21 and two arms 22 directed at right angles to the web 21. In FIGS. 5 and 6 it can be seen that the arms have slide surfaces 23 which are inclined downwards and inwards, that is to say towards one another, and which rest on the guide bars 12. As can be seen in FIG. 5, these slide surfaces form with the longitudinal axis of the arms 22 an angle such that the web 21 lies substantially above the guide bars 12. FIG. 5 also shows that the web 21 is formed by bent-over sheet material provided with a driving stop 24 which extends downwards (in accordance with FIG. 6 extending between two guide bars 12 to a point below them) and which has a bent-over blade-like extension 25 extending roughly parallel to the arms 22. A feed pin 26 is provided on each side of the driving stop, projecting at right angles therefrom and extending in the direction of the neighboring arm 22. The arms 22 are each provided with a feed lug 66, these lugs extending on the one hand towards one another and on the other hand in the longitudinal direction of the arms and in the direction of the web 21, but only to such an extent (see FIGS. 4 and 5) that they do not overlap the feed pins 26 when the spacer 20 rests on the guide bars 12.
The purpose of these arrangements will be described later on. The same applies to a driving pin 27 which is situated in the middle of the web and extends vertically upwards when the spacer lies on the guide bars 12. In this position the end faces 28 and 29 of the arms (see FIG. 5) are likewise directed vertically. As can be seen from FIG. 4, when the spacers 20 are situated in the guide passage 18 they are also guided by their end faces 28 on the bars 16 and by the ends of the feed lugs 66, remote from the web 21, on the hollow bars 17. The outer and inner sides of the arms 22 naturally likewise participate in the guiding.
The remarks made can moreover be very easily understood by reference to FIG. 2. In conjunction with FIGS. 4 to 6, FIG. 2 in fact shows that the spacers 20, when they are stacked in the guide passage 18, lie with a lower supporting surface 30 (FIG. 5) of their arms on the upper side 31 of the arms of the next lower spacer, while the lowermost spacer rests on the guide bars 12. For the sake of better understanding the last-mentioned spacer is designated 20' in FIG. 2, and the spacer lying above it is designated 20". The same differentiation is made hereinbelow in respect of the various parts of these two spacers, where these parts are mentioned at all. It can now be seen from FIG. 2 that the feed pins 26" of the lowest next to the spacer 20" lie at a slightly lower level than the ends -- facing the web 21' -- of the feed lug 66' of the lowermost spacer 20', while it should be particularly observed that these feed lugs are inclined so that their other ends extend to a point above the level of the feed pins 26". From the same Figure it can also be seen that the angle bars 16 are provided above the guide bars 12 with a cutout 32 which enables the lowermost spacer 20' to be pushed out of the guide passage 18 on the guide bars 12 (to the right in the drawing). During this movement of the lowermost spacer 20' its feed lugs 66' run on to the feed pins 26" of the spacer immediately above it and impart to the latter a downwardly directed advance in accordance with their angle of adjustment. Consequently the next to the lowest spacer 20", which because it is supported on the inclined upper side 31' of the arms of the lowermost spacer 20' will in any case move downwards on the displacement of the latter, is accelerated in the downward direction and placed on the guide bars 12. In this manner one spacer after the other can thus be brought very rapidly out of the magazine 15 along the guide bars 12, since the next spacer is advanced into the position of readiness not only by the weight of the stack of spacers, but also by a positive forward movement.
Refering against to FIG. 2, it can now be seen that the driving stop 24' of the lowermost spacer 20 in the magazine extends into the path of movement of the leading edge 8 of the newspapers 9 arriving in a fanned-out stream, this path of movement being formed by the slide bar 10 whose end 10' facing the magazine extends approximately parallel to the extension 25' of the lowermost spacer 20'. In accordance with this arrangement there is now an operative connection between the leading edge of each newspaper and the driving stop of the spacer which is lowermost at the time in question, with the consequence that, as can be seen particularly clearly in FIG. 2, each of the newspapers takes a spacer 20 out of the magazine and carries it along with it. The constrained advance of the spacer which in each particular case is next to the lowest is of particular importance in this connection, since at the usual stream feed speeds the spacers must be available very rapidly one after the other.
The spacers carried along by the individual newspapers now slide on the guide bars 12 and, as can be seen firstly from FIG. 2 and then from FIG. 3 in conjunction with FIG. 1, pass into the region of a brake device given the general designation 33. This brake device is here in the form of a rotationally driven grooved roller 34, which is disposed above the guide bars 12 with its axis parallel to them, in such a manner that the spacers travelling with the newspapers come to lie with their driving pins 27 against the end face 35 of the roller 34. The roller 34 has a helical peripheral groove 36 the widened starting portion of which has its mouth on the end face 35. The spacers 20 arriving at the roller 34 are therefore halted in the corresponding rotational positions of the roller 34 because their driving pins 37 lie against the end face 35, until the mouth of the groove reaches the respective driving pin 37. The latter is then received by the groove 36, while the respective spacer -- like all the other spacers -- can continue to move in accordance with the path of this groove 36. As an immediate consequence of this arrangement the spacers now run on to one another, being supported by the spacer or spacers whose advance has already been effected by the roller 34. For the purpose of supporting the spacers against one another use is made on the one hand of the end face 28 of the arms 22 in conjunction with the free end surface 37 of the feed lugs 26, these end faces 37 merging into a corresponding stepping of the ends of the arms 22 (see FIGS. 3 to 6). In the region of the brake device 33 there are also provided, above the guide bars 12, holding-down bars 38 which, as can be seen in FIG. 1, can extend in both directions considerably beyond the roller 36. These holding-down bars additionally ensure that the following spacers will not jump over the end faces 37 serving as stops for them. Thus, as can be seen in FIG. 3, these spacers accurately determine the mutual spacing of the successive stream-fed newspapers. The pitch of the groove 36 in the roller 34 is selected to coincide with this spacing. In these circumstances, in addition to the braking of the arriving spacers, the purpose of the roller 34 is limited to allowing the newspapers, which are supported on the spacers gripped by the groove 36, to pass through and be carried further in accordance with a determined transport plan (that is to say in a determined phase). The purpose of this arrangement will also be explained later on.
With the aid of the Figures previously mentioned the following intermediate conclusions can be drawn in connection with the mode of operation of the apparatus: the stream is passed through the nip 7 of the rollers 5 and 6, the leading edge 8 of the newspapers being raised and with the aid of the sliding bar being brought against the driving stop 24' of the spacer lying in the lowest position in the magazine 15 at the time in question. In this way, each newspaper carries with it a spacer, which is first guided on the bars 12 and then is also guided with the aid of the bars 38. The feed stream is carried further by the belts 3 and 4, the belt 3 preferably running more quickly than the other two belts, but having a surface with reduced friction in order not to damage the newspapers. The spacers carried along are braked with the aid of the brake device 33, so that they run on to one another and determine the spacing of the newspapers. In the embodiment shown in FIG. 3 the newspapers are passed on by the roller 34 while this spacing is retained, and -- as is immediately clear -- the timing is effected by the speed of rotation of the roller 34 in conjunction with the rotational position or positions in which the driving pins 27 of the spacers engage in the groove 36 and pass out of this groove.
The embodiment shown in FIG. 1 coincides basically with that shown in FIGS. 2 and 3, with the exception of the construction of the roller, which in FIG. 1 is designated 34', while as the result of this difference modified spacers are here also used. The roller 34' differs from the roller 34 in that it has a groove 36' whose pitch is progressive, so that the spacing of the spacers still lying on one another upstream of the roller is increased again in the region of the roller 34'. In addition to determining the transport plan, the roller here consequently also serves the purpose of adjusting the final spacing of the newspapers.
In this case of course the spacers accelerated by the roller 34' must correspondingly pull the newspaper forwards. For this purpose the spacers in the embodiment shown in FIG. 1 (where they are designated 20') is equipped with a pulling gripper whose one arm is formed by the extension 25 already mentioned in connection with FIGS. 4 to 6, this extension cooperating with a second gripper arm shown at 39 in FIG. 1. One possible construction of a spacer equipped with a pulling gripper is shown in FIGS. 7 to 10, where for the sake of clarity the parts which are not changed in relation to the spacer 20 are not given references. Modified references are once again allocated to modified parts.
The main difference consists of a central part 40 of the driving stop 24' or of the extension 25' thereof is punched out and extends in the form of a tongue parallel to the extension 25', which is here composed of two parts. This extension 25' and the tongue-shaped part 40 form gripper jaws into which the leading edge of the newspaper runs. A central longitudinal portion 41 of the tongue-shaped part 40 is once again separated by punching cuts from the edges of this part, as can best be seen in FIG. 7, and is stretched so that this portion 41 has a greater length than the corresponding edges 40'. This has the consequence that the portion 41 must curve and thus has a bi-stable clamp element which in addition to the position shown in solid lines in FIG. 7 and in FIG. 9 can assume a downwardly curved position (shown in a dot-and-dash line in FIG. 9). In this last-mentioned position the leading edge 8 of the newspaper 9 is held by clamping, so that the newspaper in question can be accelerated together with the spacer 20'. When the portion 41 is swung up again, the newspaper is freed and the connection can be released by corresponding acceleration of the spacer. How this is done will be explained further on in detail. First however, fundamental details in connection with the operation of the clamp grippers 25', 39 must be mentioned. In FIG. 1 an actuating device is indicated diagrammatically at 42, which has a member 43 adapted to move vertically after the style of a punch. This member 43 for transmission means coupled to it acts on the clamp portion 41 of the spacer moving past, so as to bring it into the clamping position. It is obvious that the member 43 is driven in unison with the machine. For the purpose of opening the grippers 39, 25 an opening device is disposed at the other end of the roller -- as indicated at 44, and is in turn provided with a vertically movable member 65 which is driven in unison with the machine and which brings the clamp portion 41 of the spacers 20' into the open position shown in FIG. 7. This could for example be effected with the aid of a pull magnet. It would also be conceivable for the entire part 40 to be subjected to a bending moment in order to open (or to close) the gripper. In this connection it must be vigorously emphasised that although the spacers illustrated in FIGS. 7 to 10 and provided with clamp means and their operation are entirely feasible in practice, nevertheless the description given above is mainly of a symbolic character and serves the purpose of illustrating to the specialist the basic principles of an arrangement of this kind. With this starting point, the specialist's skill and knowledge will then be sufficient to put these principles into practice.
Now that it has been explained how with the aid of the spacers, and optionally with the assistance of the roller 34 or 34', the feed stream is brought "into unison and phase," it must still be explained how the spacers are detached from the stream formation and made available for re-use after serving their purpose. In this connection reference will be made to both FIG. 1 and FIG. 3. In these Figures can be seen a blast pipe 45 downstream of the brake device 33 in the direction of flow and which has a mouth pointing substantially in the direction of flow. Compressed air is passed through this blast pipe. The air jet passing out of the mouth of the past pipe is directed on to the web of the spacers, so that when subjected to the action of this air jet they are driven by impact. Through the action of the air impact the spacers free the leading edge of the newspapers and, while the adjusted spacing is retained, this edge is laid down on the newspaper preceding it, while the spacers move to the end of the guide rods 12. In the end region of these rods is now provided a return roller 46 of an endless belt running around other guide rollers 47, 48, and 49, and on a drum 50. Commencing with the return roller 46 there are disposed along the belt 51 curved or rectilinear segments (all designated 52) of permanent-magnet material, which segments extend approximately to the passage 18 of the magazine 15. With the aid of these magnet segments the space is, whose webs are made of a magnetisable material, are now attached to the belt 51 at the end of the guide bars 12 and are carried along by the belt 51, as indicated in FIG. 1, until they each the portion of the belt extending between the drum 50 and roller 49 above the passage 18. Here the spacers are released or stripped off by a suitable construction of the guide bars 16, so that they continuously replenish the stack 19 contained in the passage. The arrangement is naturally such that this stack has a sufficient buffer stock to comply with any changes of speed of the stream feed. Similarly, the belt drive is adjusted to the delivery path of the feed stream.
The same naturally also applies to the drive, indicated at 53 in FIG. 1, for the roller 34', a buffer zone for the spacers being here again formed upstream of the roller. On the other hand, the operation of the arrangement described is usually syncronized with a following processing station or machine, which in turn requires a feed stream "in time and in phase." As an example of this, the newspapers are subjected to an individual processing operation, for example the known operation of inserting insets. For this purpose each copy of the so-called main product must be brought together with one or more copies of the previous product and/or with a supplement. An insertion machine (whatever its type) can then obviously work under far more favourable conditions if the newspapers are fed to it at regular intervals of time, and at the correct moment of time in each case. This can be achieved with the device described. At the same time it is entirely possible to provide between the insertion machine (or any other processing station, even one of completely different kind) and the device described a conveyor which individually grips the newspapers from a feed stream by means of grippers which in turn are guided at determined intervals, for example with the aid of a chain (on a circulating path). Obviously, it is immediately conceivable for the sole purpose or the main purpose of the device described to consist in bringing the stream feed formation into unison and phase in relation to a conveyor of this kind. In addition, the drive provided by the belt 3 can obviously be so adjusted that the newspapers can follow the acceleration of the spacers (in this case as at 20) through the roller 34' without being clamped.
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A device for equalizing the spacing of printed products, such as newspapers, comprises a plurality of spacers movable in a path parallel to the path of the products. Each of the spacers receives the leading edge of a printed product and is driven thereby to a braking device that causes each spacer to abut the preceding spacer. The printed products are carried by a conveyer belt system and a sill raises their leading edges ready for reception by the spacers. After leaving the braking device, the products are deposited from the spacers which are then returned to a magazine to receive further products.
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FIELD AND BACKGROUND OF INVENTION
[0001] The present invention relates generally to the field of tube extracting devices, and more particularly to an improved tube extracting device for facilitating the removal of tubes from different types of structures, such as boilers, condensers, evaporators, and the like.
[0002] A typical condenser comprises a pair of parallel tube sheets, a plurality of baffle plates, and a plurality of heat exchanger tubes. The tube sheets are located at the ends of the condenser. The baffle plates are positioned between the tube sheets and generally parallel thereto. The heat exchanger tubes extend between the tube sheets and through the baffle plates and are supported by the tube sheets. The tube sheets and baffle plates have a series of aligned holes formed therein, and the heat exchanger tubes are inserted through these holes and then expanded in the areas of the tube sheets into fluid-tight pressure contact therewith.
[0003] Because of malfunctions or normal preventive maintenance, it may be necessary to remove one or all of the tubes from the structure. This is generally accomplished by first relieving the pressure forces between the tubes and the tube sheets and then longitudinally pulling the tubes through the baffle plates and the tube sheets. Various types of devices are used to initially relieve or break the secured connection between the tubes and tube sheets, and then another apparatus is used to withdraw the tubes from the structure.
[0004] In the refurbishing of a water-tube boiler and the replacing of the tubes thereof, the tubes are conventionally removed by the use of an air hammer or the like, chipping away at the tube connection to the drum, to physically force the tube from the associated opening in the boiler drum. These methods have often resulted in damage to the drum and the opening through which the tube stub section projected.
[0005] Another method often used for removing tubing from structures is by use of a cutting torch. This is particularly common in the case of large boilers using heavy walled tubing on the order of three inches in diameter. Errors in use of the cutting torch can, of course, damage the tube sheet requiring expensive refinishing and repair work.
[0006] Prior art believed to be relevant to the present invention includes U.S. Pat. No. 4,233,730 issued to Godbe, U.S. Pat. No. 4,231,246 to issued Gorenc et al., and U.S. Pat. No. 4,180,903 issued to Hannigan, Jr., as well as, U.S. Pat. No. 2,507,201 issued to Evans, U.S. Pat. No. 2,744,429 issued to Seely and U.S. Pat. No. 3,245,247 issued to Valente.
[0007] The Godbe patent discloses a crimping tool having a hydraulic-driven ram which drives a wedge into the outside wall of the tube to crimp the tube. The crimping operation breaks the bond between the tube and tube sheet and allows the tube to be pushed from the hole.
[0008] A crimping tool for crimping a boiler tube to facilitate its removal is disclosed in the Gorenc patent.
[0009] The Hannigan, Jr. teaches a hydraulic-driven apparatus having a plurality of arms with gripping fingers for engaging and crimping the tube.
[0010] The Evans patent discloses a one-piece cutter or plow-type tool for slitting the tubes from the outside of the tube sheet to break the bond between the tube and the tube sheet.
[0011] The Seely patent teaches a particular type of tube crimper used in reducing the cross-section of a capillary tube to provide a precise flow resistance.
[0012] The Valente patent teaches a complicated device for pointing the end of tubing so that the tubing may be inserted into a drawing die.
[0013] There is a need for a simpler device for facilitating the removal of tubing, especially heavy-walled tubing from drums and/or tube sheets without damaging the drum and/or tube sheet bonding surfaces.
SUMMARY OF INVENTION
[0014] It is an object of the present invention to provide a novel device for breaking the seal between a tube and a hole in a drum or tube sheet.
[0015] It is a further object of the invention to provide a simplified device for facilitating the removal of tubes from a drum or tube sheet without damaging the tube sheet bonding surfaces.
[0016] Accordingly, an object of the invention is to provide a tube extraction device which facilitates the removal of a tube from a tube hole in a drum. The device comprises a housing which is mounted over an exterior surface of the drum. The housing has an opening which receives a part of the tube. The device has a wedge which is slidably mounted in the housing. The wedge has a slanted face and a bottom edge. A thrusting ram is slidably mounted in the housing. The side thrusting ram laterally moves the wedge so that the slanted face indents the tube inwardly. A drive down ram is slidably mounted in the housing. The drive down ram drives the wedge down into the zone between the tube outside wall and the tube hole so that the tube collapses into the tubes hole.
[0017] It will be seen that use of the device is very rapid and removal of a tube from its secured connection in the boiler drum opening is materially facilitated, thereby materially reducing the costs involved in retubing a boiler or replacing a tube. The tool is light and portable enough so that a single workman utilizing the tool can readily and rapidly accomplish the job of removing the boiler tubes from a boiler. In the past, such a retubing operation normally required several workmen.
[0018] The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the drawings:
[0020] FIG. 1 is a front elevational view of the external tube extracting device of the invention;
[0021] FIG. 2 is a side elevational view of the external tube extracting device of the invention;
[0022] FIG. 3 is a top view of the external tube extracting device of the invention; and
[0023] FIG. 4 is a top view of the external tube extracting device of the invention having multiple ram assemblies.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Referring now to the drawings, in which like reference numerals are used to refer to the same or similar elements, FIG. 1 shows a side view of the tube extracting device 100 . The device has a housing 10 preferably comprised of two parts connected by typical fasteners, such as bolts 11 . The housing 10 is supported on an external surface of a drum 200 of a typical boiler, heat exchanger or the like. The drum 200 houses conventional tube(s) 300 in tube holes 210 . The tubes 300 are typically expanded into the tube holes 210 thereby forming a joint 215 between the tube 300 and the tube hole 210 .
[0025] A tube stub 310 extends out of the tube hole 210 . The housing 10 has a bottom opening 12 and a top opening 14 which receive the tube stub 310 . The tube stub 310 exits the housing 10 from the top opening 14 .
[0026] A wedge 20 is slidably mounted in the housing 10 . The wedge 20 has a face 22 adjacent the portion of the tube stub 310 . The face 22 of the wedge 20 preferably has a curved contour 23 as illustrated in FIG. 3 . The face 22 has a top edge 24 which is closest to the tube and a bottom edge 26 which is farthest from the tube 300 . Thus, the face 22 of the wedge 20 slants downward away from the tube 300 . The bottom edge 26 is preferably round.
[0027] A side thrusting ram 40 is slidably mounted in the housing 10 preferably behind the wedge 20 . The side thrusting ram 40 is connected to the wedge 20 by conventional means. The side thrusting ram 40 is a device well-known in the prior art. For example, the side thrusting ram includes control valves (not shown), spring return (not shown), a piston 500 (shown hidden) and a cylinder, which are all conventional parts of a ram. The side thrusting ram 40 is preferably coupled to a typical hydraulic pump (not shown) which powers the side thrusting ram 40 . The hydraulic pump provides pressurized hydraulic fluid to the cylinder and causes an outward extension of the side thrusting ram 40 . The spring may automatically return the side thrusting ram 40 inwardly back to its starting position upon shutting off the flow of hydraulic fluid to the power unit via the control valve.
[0028] A conventional drive down ram 50 is also slidably mounted in the housing 10 preferably above the wedge 20 . The drive down ram 50 is connected to the wedge 20 by means well-known in the prior art. The drive down ram 50 , preferably hydraulically powered, drives the bottom edge 26 of the wedge 20 into the indented tube whereby the tube 300 collapses into the tube hole. Tube 300 , as collapsed, is then easily removed from the hole by conventional extracting means. When the drive down ram 50 is in operation, the side thrusting ram 40 moves downward or upward along with the wedge 20 .
[0029] A guide means maintains the wedge 20 in operational alignment with the drive down ram 50 . The guide means generally comprises a key and carriage assembly 60 . As shown in FIG. 2 , a key 62 , preferably a T-shaped member, is connected to the top of the wedge 20 . A carriage 64 , preferably a C-shaped member, is connected to the bottom end of the drive down ram 50 . The key 62 slidably engages the carriage 64 to connect the drive down ram 50 to the wedge 20 and allows the wedge 20 to move laterally with respect to the tube hole 210 .
[0030] Operation of the tube extracting device 100 for removing a tube from anchored relationship to a boiler drum is preferably as follows. In the use of the present device 100 , the device 100 is positioned down over the tube stub 310 such that the tube stub 310 may project through the housing 10 . Thereupon, the control valve for the power means is actuated to apply pressurized fluid via hose (not shown) to the cylinder, causing extension of the side thrust ram 40 , and movement of the wedge 20 into engagement with the tube stub 310 .
[0031] The slide thrust ram 40 laterally drives the wedge 20 into the tube stub 310 . As illustrated in FIG. 2 , the face 22 of the wedge 20 applies a force to the wall of the tube stub 310 , indenting the tube along an area running generally lengthwise thereof. The wedge 20 moves into the tube stub 310 to a point where the bottom edge 26 is above the joint 215 formed between the tube 300 and the tube hole 210 . The face 22 of the wedge 20 applies a force to the tube stub 310 , running vertically lengthwise along the tube stub 310 , causing inward crimping lengthwise along tube stub 310 as shown for instance in FIG. 3 . This inward crimping deforms the periphery of the tube stub 310 section inwardly, pulling the tube 300 away from the inside wall of the tube hole 210 from its attached or secured condition in the boiler drum 200 . Thus, the side thrust ram 40 creates a gap between the tube 300 and the inside wall of the tube hole 210 . When the bottom edge 26 of the wedge 20 is over such gap, the control valve shuts supply of pressurized fluid to the side thrust ram 40 and, in turn, supplies pressurized fluid to the drive down ram 50 . The drive down ram 50 drives the wedge 20 lengthwise down the tube stub 310 whereupon it collapses tube 300 downwardly into the interior of the tube hole 210 . Tube 300 , as collapsed, can then be readily removed through the tube hole 210 in the drum.
[0032] The device 100 will collapse the tube 300 such that the tube 300 will readily fall out of the tube hole 210 upon retraction of the device 100 . Depending on the thickness of the tube 300 , diameter of the tube hole 210 or whether there are ring grooves into which the tube 300 had been originally expanded, the collapsed tube 300 can attach to the wedge 20 and be removed upon retraction of the wedge 20 from the tube hole 210 .
[0033] In a preferred embodiment, a keeper plate 16 is secured to the portion of the tube stub 310 which exits the housing 10 . The keeper plate 16 is secured to the tube stub 310 by conventional methods such as welding or clamping. The wedge 20 creates a reactive force when it strikes the tube stub 310 which tends to move the device 100 away from the drum 200 . The keeper plate 16 stabilizes the device 100 and prevents the device 100 from moving away from the drum 200 .
[0034] In another embodiment of the present invention, as shown in FIG. 4 , the tube extracting device 100 comprises a plurality of ram assemblies 30 each having a wedge 20 , a side thrust ram 40 , and a drive down ram 50 . This embodiment operates in the following manner. The side thrust ram 40 of the first ram assembly 30 laterally moves the wedge 20 into the tube stub 310 , followed in sequence by the side thrust rams 40 of the remaining ram assemblies 30 . Therefore, the tube stub 310 is indented at multiple angles by the wedges 20 of the ram assemblies 30 . The drive down ram 50 of the first ram assembly 30 drives the wedge 20 into the tube stub 310 . The drive down rams 50 and wedges 20 of the remaining ram assemblies 30 follow in sequence. The drive down rams 50 collapses the tube 300 into the tube hole 210 .
[0035] In yet another embodiment of the present invention, the tube extracting device 100 comprising a plurality of ram assemblies 30 . In this embodiment each of the side thrust ram 40 of the two or more ram assembly 30 concurrently indent the tube stub 310 . The drive down ram 50 of each of the two or more ram assemblies 30 then concurrently drive wedge 20 of the two or more ram assemblies down tube stub 310 . The drive down ram 50 of the two or more ram assemblies 30 concurrently collapses the tube 300 into the tube hole 210 .
[0036] While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A tube extraction device which facilitates the removal of a tube from a tube hole in a drum. The tube extraction device comprises a housing which is mounted over an exterior surface of the drum. The housing has an opening which receives a removed part of the tube. A wedge having a slanted face and a bottom edge is slidably mounted in the housing. At least one side thrusting ram and at least one drive down ram are slidably mounted in the housing. The side thrusting ram laterally moves the wedge so that the slanted face indents the tube inwardly, while the drive down ram drives the wedge down into the tube so that the tube collapses in the tube hole.
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FIELD OF THE INVENTION
[0001] This invention relates generally to the art of making and using oilfield treatment in severe environments. More particularly it relates to methods of using fluids for environments at high temperature in contact with carbon dioxide and especially to methods of using such fluids in fracturing fluids in a well from which oil and/or gas can be produced.
BACKGROUND
[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0003] In typical wellbore operations, various treatment fluids may be pumped into the well and eventually into the formation to restore or enhance the productivity of the well. For example, a reactive or non-reactive “fracturing fluid” or a “frac fluid” may be pumped into the wellbore to initiate and propagate fractures in the formation thus providing flow channels to facilitate movement of the hydrocarbons to the wellbore so that the hydrocarbons may be pumped from the well. In such fracturing operations, the fracturing fluid is hydraulically injected into a wellbore penetrating the subterranean formation and is forced against the formation strata by pressure. The formation strata are forced to crack and fracture, and a proppant is placed in the fracture by movement of a viscous-fluid containing proppant into the crack in the rock. The resulting fracture, with proppant in place, provides improved flow of the recoverable fluid (i.e., oil, gas or water) into the wellbore. In another example, a reactive stimulation fluid or “acid” may be injected into the formation. Acidizing treatment of the formation results in dissolving materials in the pore spaces of the formation to enhance production flow. It is common in all these types of operations to add further chemical components to treat the formation. In the case of proppant, scale inhibitors, filter cake remover, surfactant, gas hydrate inhibitors and other chemicals may be used.
[0004] Viscosifying agent based on polymer gels have been widely used for fracturing operations. However, none of said methods allows guar or guar derivative-based frac fluids when foamed or energized with CO 2 to be used at elevated temperatures due to the low pH caused by CO 2 . The applicants found that some salt can be used with guar or guar derivatives to be usable at elevated temperatures.
SUMMARY
[0005] In a first aspect, a method is disclosed. The method comprises the step of providing a composition comprising a carrier fluid, a polymer viscosifying agent, and a formate ion compound; contacting the composition with carbon dioxide; and allowing the composition to be at a temperature above 100 degrees Celsius.
[0006] In a second aspect, a method of treating a subterranean formation from a wellbore is disclosed. The method comprises the step of providing a composition comprising a carrier fluid, a polymer viscosifying agent, carbon dioxide and a formate ion compound; injecting into a wellbore, the composition; contacting the composition with the subterranean formation, wherein the temperature is above 100 degrees Celsius at this contact; and allowing the composition to treat the subterranean formation.
[0007] In a third aspect, a composition is disclosed. The composition comprises a carrier fluid, a polymer viscosifying agent, carbon dioxide and a formate ion compound, wherein the carbon dioxide is present with a foam quality of from about 25% to about 80%.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a graph comparing viscosity over time at about 280° F. (138° C.) for Fluid 1 in 400 psi N 2 , for Fluid 2 in 400 psi CO 2 , and for Fluid 3 containing 11% potassium formate in 400 psi CO 2 , respectively.
[0009] FIG. 2 is a graph comparing viscosity over time at about 280° F. (138° C.) for Fluid 1 in 400 psi N 2 , for Fluid 2 in 400 psi CO 2 , and for Fluid 3 containing 11% potassium formate in 400 psi CO 2 , respectively (all fluids contained 2% KCl).
[0010] FIG. 3 is a graph comparing viscosity over time at about 225° F. (107° C.) for Fluid 1 in 400 psi N 2 , for Fluid 2 in 400 psi CO 2 , and for Fluid 3 containing 11% potassium formate in 400 psi CO 2 , respectively (all fluids contained 2% KCl).
DETAILED DESCRIPTION
[0011] At the outset, it should be noted that in the development of any actual embodiments, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system and business related constraints, which can vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
[0012] The description and examples are presented solely for the purpose of illustrating embodiments of the invention and should not be construed as a limitation to the scope and applicability of the invention. In the summary of the invention and this detailed description, each numerical value should be read once as modified by the term “about” (unless already expressly so modified), and then read again as not so modified unless otherwise indicated in context. Also, in the summary of the invention and this detailed description, it should be understood that a concentration range listed or described as being useful, suitable, or the like, is intended that any and every concentration within the range, including the end points, is to be considered as having been stated. For example, “a range of from 1 to 10” is to be read as indicating each and every possible number along the continuum between about 1 and about 10. Thus, even if specific data points within the range, or even no data points within the range, are explicitly identified or refer to only a few specific, it is to be understood that inventors appreciate and understand that any and all data points within the range are to be considered to have been specified, and that inventors possession of the entire range and all points within the range disclosed and enabled the entire range and all points within the range.
[0013] As used herewith the term “gel” means a substance selected from the group consisting of (a) colloids in which the dispersed phase has combined with the continuous phase to produce a viscous, jelly-like product, (b) crosslinked polymers, and (c) mixtures thereof.
[0014] According to a first embodiment, the composition comprises a carrier fluid, a polymer viscosifying agent, carbon dioxide and a formate ion compound.
[0015] The carrier fluid may be any liquid in which the crosslinkable polymer and crosslinking agent can be dissolved, mixed, suspended or otherwise dispersed to facilitate gel formation. The carrier fluid may be fresh water, an aqueous composition, brine, and/or may include a brine. Also the carrier fluid may be an oil-based fluid including a gelled, foamed, or otherwise viscosified oil.
[0016] The fluid composition can be foamed or energized with carbon dioxide in a separate phase, for example with a foam quality of from about 25% to about 80%. The foam quality is the fraction of the non-aqueous phase. The fluid composition can also be in equilibrium with the carbon dioxide atmosphere at a pressure from above 0 psi to about 400 psi or higher.
[0017] The formate ion compound may be a formate salt or a formic acid. The formate ion compound may be present in concentration varying from below 0.1% to above 15% bw. When the formate ion compound is a formate salt, it may be present as a potassium formate, sodium formate, or other formates, or the combination.
[0018] The composition can further comprise an ion compound selected from the group consisting of: sulfite, oxalate, phosphate, ascorbate, and the combination thereof.
[0019] The polymer viscosifying agent may be hydratable gels (e.g. guars, poly-saccharides, xanthan, diutan, hydroxy-ethyl-cellulose, etc.), a cross-linked hydratable gel. The polymer viscosifying agent may be a crosslinkable polymer and a crosslinking agent capable of crosslinking the polymer.
[0020] A crosslinked polymer is generally formed by reacting or contacting proper proportions of the crosslinkable polymer with the crosslinking agent. However, the gel-forming composition need only contain either the crosslinkable polymer or the crosslinking agent. When the crosslinkable polymer or crosslinking agent is omitted from the composition, the omitted material is usually introduced into the subterranean formation as a separate slug, either before, after, or simultaneously with the introduction of the gel-forming composition. The composition may comprise at least the crosslinkable polymer or monomers capable of polymerizing to form a crosslinkable polymer. In another embodiment, the composition comprises both (a) the crosslinking agent and (b) either (i) the crosslinkable polymer or (ii) the polymerizable monomers capable of forming a crosslinkable polymer.
[0021] Embodiments of crosslinkable polymer include, for example, polysaccharides such as substituted galactomannans, such as guar gums, high-molecular weight polysaccharides composed of mannose and galactose sugars, or guar derivatives such as hydroxypropyl guar (HPG), carboxymethylhydroxypropyl guar (CMHPG) and carboxymethyl guar (CMG), hydrophobically modified guars, guar-containing compounds, and synthetic polymers. Crosslinking agents based on boron, titanium, zirconium or aluminum complexes are typically used to increase the effective molecular weight of the polymer and make them better suited for use in high-temperature wells.
[0022] Other embodiments of crosslinkable polymer include polyvinyl polymers, polymethacrylamides, cellulose ethers, lignosulfonates, and ammonium, alkali metal, and alkaline earth salts thereof. More specific examples of other polymers are acrylamide polymers and copolymers, acrylic acid-acrylamide copolymers, acrylic acid-methacrylamide copolymers, polyacrylamides, partially hydrolyzed polyacrylamides, partially hydrolyzed polymethacrylamides, polyvinyl alcohol, polyvinyl acetate, polyalkyleneoxides, carboxycelluloses, carboxyalkylhydroxyethyl celluloses, hydroxyethylcellulose, other galactomannans, heteropolysaccharides obtained by the fermentation of starch-derived sugar (e.g., xanthan gum), diutan, and ammonium and alkali metal salts thereof.
[0023] Cellulose derivatives are also used in an embodiment, such as hydroxyethylcellulose (HEC) or hydroxypropylcellulose (HPC), carboxymethylhydroxyethylcellulose (CMHEC) and carboxymethycellulose (CMC), with or without crosslinkers. Xanthan, diutan, and scleroglucan, three biopolymers, have been shown to have excellent proppant-suspension ability even though they are more expensive than guar derivatives and therefore have been used less frequently unless they can be used at lower concentrations.
[0024] The crosslinkable polymer is available in several forms such as a water solution or broth, a gel log solution, a dried powder, and a hydrocarbon emulsion or dispersion. As is well known to those skilled in the art, different types of equipment are employed to handle these different forms of crosslinkable polymers.
[0025] Other type of crosslinking agents may include organic and inorganic compounds well known to those skilled in the art. Exemplary organic crosslinking agents include, but are not limited to, aldehydes, dialdehydes, phenols, substituted phenols, hexamethylenetetramine and ethers. Phenol, phenyl acetate, resorcinol, glutaraldehyde, catechol, hydroquinone, gallic acid, pyrogallol, phloroglucinol, formaldehyde, and divinylether are some of the more typical organic crosslinking agents. Typical inorganic crosslinking agents are polyvalent metals as disclosed previously, chelated polyvalent metals, and compounds capable of yielding polyvalent metals.
[0026] According to a further embodiment, the composition may comprise a surfactant. Surfactants may be used to reduce the surface tension between the solvent and the gas. The surfactants may be water-soluble and have sufficient foaming ability to enable the composition, when traversed by a gas, to foam and, upon curing, form a foamed gel. Typically, the surfactant is used in a concentration of up to about 10, about 0.01 to about 5, about 0.05 to about 3, or about 0.1 to about 2 weight percent.
[0027] The surfactant may be substantially any conventional anionic, cationic or nonionic surfactant. Anionic, cationic and nonionic surfactants are well known in general and are commercially available. Exemplary surfactants include, but are not limited to, alkyl polyethylene oxide sulfates, alkyl alkylolamine sulfates, modified ether alcohol sulfate sodium salt, sodium lauryl sulfate, perfluoroalkanoic acids and salts having about 3 to about 24 carbon atoms per molecule (e.g., perfluorooctanoic acid, perfluoropropanoic acid, and perfluorononanoic acid), modified fatty alkylolamides, polyoxyethylene alkyl aryl ethers, octylphenoxyethanol, ethanolated alkyl guanidine-amine complexes, condensation of hydrogenated tallow amide and ethylene oxide, ethylene cyclomido 1-lauryl, 2-hydroxy, ethylene sodium alcoholate, methylene sodium carboxylate, alkyl arylsulfonates, sodium alkyl naphthalene sulfonate, sodium hydrocarbon sulfonates, petroleum sulfonates, sodium linear alkyl aryl sulfonates, alpha olefin sulfonates, condensation product of propylene oxide with ethylene oxide, sodium salt of sulfated fatty alcohols, octylphenoxy polyethoxy ethanol, sorbitan monolaurate, sorbitan monopalmitate, sorbitan trioleate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, dioctyl sodium sulfosuccinate, modified phthalic glycerol alkyl resin, octylphenoxy polyethoxy ethanol, acetylphenoxy polyethoxy ethanol, dimethyl didodecenyl ammonium chloride, methyl trioctenyl ammonium iodide, sodium tridecyl ether sulfate, trimethyl decenyl ammonium chloride, and dibutyl dihexadecenyl ammonium chloride.
[0028] According to a further embodiment, another foaming gas may be present. The foaming gas is usually a noncondensable gas. Exemplary noncondensable gases include air, oxygen, hydrogen, noble gases (helium, neon, argon, krypton, xenon, and radon), natural gas, hydrocarbon gases (e.g., methane, ethane), and nitrogen.
[0029] The amount of gas injected (when measured at the temperature and pressure conditions in the subterranean formation being treated) is generally about 1 to about 99 volume percent based upon the total volume of treatment fluids injected into the subterranean formation (i.e., the sum of the volume of injected gas plus the volume of injected foamable, gel-forming composition).
[0030] According to a further embodiment, the composition may further comprise proppant. Any conventional proppant (gravel) can be used. Such proppants (gravels) can be natural or synthetic (including but not limited to glass beads, ceramic beads, sand, and bauxite), coated, or contain chemicals; more than one can be used sequentially or in mixtures of different sizes or different materials. The proppant may be resin coated, pre-cured resin coated, provided that the resin and any other chemicals that might be released from the coating or come in contact with the other chemicals of the Invention are compatible with them. Proppants and gravels in the same or different wells or treatments can be the same material and/or the same size as one another and the term “proppant” is intended to include gravel in this discussion. In general the proppant used will have an average particle size of from about 0.15 mm to about 2.39 mm (about 8 to about 100 U.S. mesh), more particularly, but not limited to 0.25 to 0.43 mm (40/60 mesh), 0.43 to 0.84 mm (20/40 mesh), 0.84 to 1.19 mm (16/20), 0.84 to 1.68 mm (12/20 mesh) and 0.84 to 2.39 mm (8/20 mesh) sized materials. Normally the proppant will be present in the slurry in a concentration of from about 0.12 to about 0.96 kg/L, or from about 0.12 to about 0.72 kg/L, or from about 0.12 to about 0.54 kg/L. The viscosified proppant slurry can be designed for either homogeneous or heterogeneous proppant placement in the fracture, as known in the art.
[0031] According to a further embodiment, the composition may further comprise additives as breakers, anti-oxidants, corrosion inhibitors, delay agents, biocides, buffers, fluid loss additives, pH control agents, solid acids, solid acid precursors, organic scale inhibitors, inorganic scale inhibitors, demulsifying agents, paraffin inhibitors, corrosion inhibitors, gas hydrate inhibitors, asphaltene treating chemicals, foaming agents, fluid loss agents, water blocking agents, EOR enhancing agents, or the like. The additive may also be a biological agent.
[0032] The fluid may be used, for example in oilfield treatments. The fluids may also be used in other industries, such as in household and industrial cleaners, agricultural chemicals, personal hygiene products, cosmetics, pharmaceuticals, printing and in other fields.
[0033] The fluid may be used for carrying out a variety of subterranean treatments, where a viscosified treatment fluid may be used, including, but not limited to, drilling operations, fracturing treatments, and completion operations (e.g., gravel packing). In some embodiments, the fluid may be used in treating a portion of a subterranean formation. In certain embodiments, the fluid may be introduced into a well bore that penetrates the subterranean formation. Optionally, the fluid further may comprise particulates and other additives suitable for treating the subterranean formation. For example, the fluid may be allowed to contact the subterranean formation for a period of time sufficient to reduce the viscosity of the treatment fluid. In some embodiments, the fluid may be allowed to contact hydrocarbons, formations fluids, and/or subsequently injected treatment fluids, thereby reducing the viscosity of the treatment fluid. After a chosen time, the fluid may be recovered through the well bore.
[0034] Accordingly, the composition fluid is especially suitable for downhole application in high temperatures above 212° F. (100° C.), or above 250° F. (121° C.), or above 270° F. (132° C.) or even above 280° F. (138° C.).
[0035] The fluids are also suitable for gravel packing, or for fracturing and gravel packing in one operation (called, for example frac and pack, frac-n-pack, frac-pack, StimPac treatments, or other names), which are also used extensively to stimulate the production of hydrocarbons, water and other fluids from subterranean formations. These operations involve pumping a slurry of “proppant” (natural or synthetic materials that prop open a fracture after it is created) in hydraulic fracturing or “gravel” in gravel packing. In low permeability formations, the goal of hydraulic fracturing is generally to form long, high surface area fractures that greatly increase the magnitude of the pathway of fluid flow from the formation to the wellbore. In high permeability formations, the goal of a hydraulic fracturing treatment is typically to create a short, wide, highly conductive fracture, in order to bypass near-wellbore damage done in drilling and/or completion, to ensure good fluid communication between the rock and the wellbore and also to increase the surface area available for fluids to flow into the wellbore.
[0036] Gravel is also a natural or synthetic material, which may be identical to, or different from, proppant. Gravel packing is used for “sand” control. Sand is the name given to any particulate material from the formation, such as clays, that could be carried into production equipment. Gravel packing is a sand-control method used to prevent production of formation sand, in which, for example a steel screen is placed in the wellbore and the surrounding annulus is packed with prepared gravel of a specific size designed to prevent the passage of formation sand that could foul subterranean or surface equipment and reduce flows. The primary objective of gravel packing is to stabilize the formation while causing minimal impairment to well productivity. Sometimes gravel packing is done without a screen. High permeability formations are frequently poorly consolidated, so that sand control is needed; they may also be damaged, so that fracturing is also needed. Therefore, hydraulic fracturing treatments in which short, wide fractures are wanted are often combined in a single continuous (“frac and pack”) operation with gravel packing. For simplicity, in the following we may refer to any one of hydraulic fracturing, fracturing and gravel packing in one operation (frac and pack), or gravel packing, and mean them all.
[0037] To facilitate a better understanding of some embodiments, the following examples of embodiments are given. In no way should the following examples be read to limit, or define, the scope of the embodiments described herewith.
EXAMPLES
[0038] Series of experiments were conducted to demonstrate properties of compositions and methods as disclosed above.
Example 1
Prior Art
[0039] In a first example, a fluid according to prior art is prepared. The Fluid 1 was prepared with tap water, 0.1% tetramethyl ammonium chloride, 0.6% carboxymethyl hydroxypropyl guar (CMHPG), 0.036% sodium bicarbonate, and 0.12% sodium thiosulfate pentahydrate. The fluid pH was adjusted to about 5 with acetic acid, and then about 0.04% sodium zirconium lactate was added as the crosslinker. The gel pH was about 5.2. The viscosity at 138° C. (280° F.) was measured with a Fann50-type viscometer, following the API RP 39 schedule. The viscometer was connected to a gas cylinder, and the gas type and gas pressure could be selected for the fluid tested in the viscometer. In one case, the gel was tested in the 400 psi nitrogen (N 2 ) atmosphere. In another case, the same gel was tested in the 400 psi carbon dioxide (CO 2 ) atmosphere. The gel viscosity stayed above 100 cP (at the shear rate of 100/s) for about 41 minutes in N 2 , while the gel viscosity stayed above 100 cP for only about 14 minutes in CO 2 . The comparison between the 2 cases clearly shows that CO 2 could damage the gel at high temperatures. The damage could be caused by the CO 2 in the gel that lowered the fluid pH. Guar and guar derivative-based gels can be damaged by low pH, especially at elevated temperatures. When 2.5 atm (about 37 psi) CO 2 is dissolved in water, the pH drops to about 3.7. When 10 atm (about 147 psi) CO 2 is dissolved in water, the pH drops to about 3.4. In the tests shown here, the CO 2 pressure was about 400 psi.
Example 2
[0040] In this example, Fluid 1 was prepared with tap water, 0.1% tetramethyl ammonium chloride, 0.6% CMHPG, 0.036% sodium bicarbonate, and 0.12% sodium thiosulfate pentahydrate. The fluid pH was adjusted to about 5 with acetic acid, and then about 0.04% sodium zirconium lactate was added as the crosslinker. The gel pH was about 5.2. The viscosity at 138° C. (280° F.) was measured with a Fann50-type viscometer, following the API RP 39 schedule. The viscosity of Fluid 1 was measured in about 400 psi N 2 atmosphere. Fluid 2 was similarly prepared as Fluid 1 , and the gel was measured in about 400 psi CO 2 atmosphere. Fluid 3 was similarly prepared as Fluid 1 , but with about 11% (wt) potassium formate mixed and dissolved in the fluid, and Fluid 3 was measured in about 400 psi CO 2 atmosphere. The viscosity curves are shown in FIG. 1 . Fluid 1 gel viscosity stayed above 100 cP (at 100/s) for about 41 minutes in N 2 , while Fluid 2 viscosity stayed above 100 cP for only about 14 minutes in CO 2 . With 11% potassium formate in Fluid 3 , the gel viscosity stayed above 100 cP for about 43 minutes in CO 2 , comparable to Fluid 1 (without potassium formate) in N 2 . The comparison among the above 3 fluids clearly shows that formate protects the fluid from the CO 2 damage at high temperatures.
Example 3
[0041] In this example, the fluid with dual salts (for example, with both formate and KCl) is tested. Fluid 1 was prepared with tap water, 2% KCl, 0.1% tetramethyl ammonium chloride, 0.6% CMHPG, 0.036% sodium bicarbonate, and 0.12% sodium thiosulfate pentahydrate. The fluid pH was adjusted to about 5 with acetic acid, and then about 0.04% sodium zirconium lactate was added as the crosslinker. The gel pH was about 5.2. The viscosity at 138° C. (280° F.) was measured with a Fann50-type viscometer, following the API RP 39 schedule. Fluid 1 was measured in about 400 psi N 2 atmosphere. Fluid 2 was similarly prepared as Fluid 1 , and the gel was measured in about 400 psi CO 2 atmosphere. Fluid 3 was similarly prepared as Fluid 1 , but with about 11% (wt) potassium formate mixed and dissolved in the fluid, and Fluid 3 was measured in about 400 psi CO 2 atmosphere. The viscosity curves are shown in FIG. 2 . Fluid 1 gel viscosity stayed above 100 cP (at 100/s) for over 60 minutes in N 2 , while the gel viscosity of Fluid 2 stayed above 100 cP for only about 13 minutes in CO 2 . With 11% potassium formate in Fluid 3 , the gel viscosity stayed above 100 cP for about 42 minutes in CO 2 , comparable to Fluid 1 (without potassium formate) in N 2 . The comparison among the above 3 cases again shows that formate could protect the fluid from the CO 2 damage at high temperatures.
Example 4
[0042] In this example, the formate salt is tested with another viscosifying agent/crosslinker. Fluid 1 was prepared with lab water, 2% KCl, 0.6% guar, 0.12% sodium bicarbonate, 0.24% sodium thiosulfate pentahydrate, 0.2% acetic acid, 0.04% glycolic acid, and 0.08% triethanolamine titanate (the crosslinker). The gel pH was about 4.5. The viscosity at 107° C. (225° F.) was measured with a Fann50-type viscometer, following the API RP 39 schedule. Fluid 1 was measured in about 400 psi N 2 atmosphere. Fluid 2 was similarly prepared as Fluid 1 , and was measured in about 400 psi CO 2 atmosphere. Fluid 3 was similarly prepared as Fluid 1 , but with about 11% (wt) potassium formate mixed and dissolved in the fluid, and Fluid 3 was measured in about 400 psi CO 2 atmosphere. The viscosity curves are shown in FIG. 3 . The viscosity of Fluid 1 stayed above 100 cP (at 100/s) for about 65 minutes in N 2 , while the viscosity of Fluid 2 stayed above 100 cP for about 50 minutes in CO 2 . With 11% potassium formate in Fluid 3 , the gel viscosity stayed above 100 cP for over 2 hours in CO 2 with enhanced viscosity values. The comparison among the above 3 fluids shows that formate protects Fluid 3 from the CO 2 damage at high temperatures.
[0043] The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope of the embodiments described herewith. Accordingly, the protection sought herein is as set forth in the claims below.
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A method for treating a subterranean formation is made of steps of providing a composition comprising a carrier fluid, a polymer viscosifying agent, carbon dioxide and a formate salt or formic acid; injecting into a wellbore, the composition; contacting the composition with the subterranean formation, wherein the temperature is above 100 degrees Celsius at this contact; and allowing the composition to treat the subterranean formation.
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FIELD OF THE INVENTION
The field of this invention relates to tools usable for retrieval of objects from subterranean wells. There are generally two types of these tools. A spear engages the inside of the stuck object while an overshot engages the outside of a stuck object. As referred to in this patent application, the words "fishing tool," "spear," and "overshot" will be used interchangeably such that fishing tool refers to both spears and overshots, a spear also refers to an overshot, while an overshot also refers to a spear.
BACKGROUND OF THE INVENTION
Many times during operations in a wellbore, objects become stuck and must be retrieved from the wellbore. Sometimes the casing or tubing can experience a catastrophic failure and must be retrieved from the wellbore. In the past, various mechanical designs have been used which generally involve a series of mechanically actuated grippers to slips to grab the object to be retrieved or "fish" so that it can be brought to the surface. Many of these designs employed shear pins that have to be sheared to allow release from the fish, if required. These tools were not resettable because once the shear pin was broken the fishing tool had to be brought to the surface so that the shear pin could be redressed. Additionally, the use of shear pins limited the upward pull that could be exerted on the fishing tool. Operators of fishing tools that had shear pins had to be careful not to exert too great a pulling force or else the fishing tool would accidently release the fish. Another drawback of shear pins was that they would release at smaller values of forces than anticipated. This was primarily due to the cyclical stresses imposed on shear pins which, over time, would weaken them and make them release or fail at pulling forces lower than anticipated.
Various tools, in the past, have employed different mechanisms to set the slips. Some have done so mechanically, while others have done so hydraulically. Typical of such tools are U.S. Pat. Nos. 808,378 (mechanically set); 803,450 (hydraulically set); 1,457,139 (hydraulically set); 1,728,136 (hydraulically set); 1,619,254 (hydraulically set); 1,580,352 (hydraulically set); 1,621,947 (hydraulically set); 1,638,494 (hydraulically set); 1,712,898 (hydraulically set); 1,779,123; 1,794,652; 1,815,462; 1,917,135; 2,141,987; 2,290,409; 2,806,534; 2,732,901; 3,638,989; and 3,262,501. Some of these tools employ hydraulic force to move a piston to in turn move a mechanical member which in turn sets the slips for gripping. Thereafter, some mechanical action is required to release the slips, such as breaking a shear pin or by pulling up on the tool with sufficient force. Also of interest is European Application 0213798, which discloses a packer retrieval assembly. This device presents two different outside diameters so that it can be inserted through a packer and expanded to its larger diameter for retrieving the packer. This apparatus also uses shear pins to actuate from one position to another. U.S. Pat. No. 4,616,721 shows a packer retrieval tool having a milling feature for cutting loose the slips. This tool can disengage the packer only by failure of a ring component from hoop tension. At that point, the packer falls to its original position and the tool must be removed from the well to be reset.
Also of interest to the field of this invention is a packer retrieving tool product No. 646-17 made by Baker Oil Tools and referred to as BAKER 43 RETRIEVA-D LOK-SET® which is used to retrieve BAKER 43 RETRIEVA-D LOK-SET® packers.
A fishing tool that releases hydraulically and which can release from the fish and reattach to the fish without removal to the surface is illustrated in U.S. Pat. No. 5,242,201.
SUMMARY OF THE INVENTION
A fishing tool is disclosed which is responsive to hydraulic pressure to move away support for collets to allow the collects to deflect and make contact with the stuck object. Upon removal of the hydraulic force, the support for the collets is returned, preferably by a biasing spring, to its original position to lend support for the collets while the collets have engaged the stuck object. The object can then be retrieved to the surface. Application of further hydraulic force while the object engaged releases the support for the collects which allows the collets to disengage from the object. The process can be repeated to obtain successive releases and engagements with the stuck object without taking the fishing tool out of the wellbore.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a sectional view of the spear of the present invention in the run-in position.
FIG. 2 is the view of FIG. 1 with hydraulic pressure applied to the spear to remove support for the collets.
FIG. 3 is the view of FIG. 2 showing advancement of the spear into the fish.
FIG. 4 is the view of FIG. 3 with the hydraulic pressure removed and an upward force applied to the spear to firmly engage the fish.
FIG. 5 is the run-in position in a sectional view of an overshot of the present invention.
FIG. 6 is the view of FIG. 5 with hydraulic pressure applied to the overshot to remove support for the collets.
FIG. 7 is the view of FIG. 6 showing the overshot advanced over the fish while hydraulic pressure is applied.
FIG. 8 is the view of FIG. 7 showing the removal of hydraulic pressure combined with an upward pull on the overshot to firmly engage the overshot to the fish.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The apparatus A of the present invention is shown in the run-in position in FIG. 1. It has a top sub 10 which has a thread 12. Thread 12 can be used to engage rigid or coiled tubing (not shown). The top sub 10 has a thread 14 which engages the collet member 16. The collet member terminates in a plurality of fingers 18, each of which terminates in a head 20. Collet member 16 has an internal shoulder 22 which supports a spring 24. Spring 24 bears on shoulder 26 of mandrel 28. Mandrel 28 has a central bore 30 which results from a taper 32 adjacent its upper end 34. Bore 30 continues beyond taper 32 into top sub 10 so that it is in fluid communication with the rigid tubing or coiled tubing (not shown). Mandrel 28 is mounted for relative movement with respect to collet member 16 with O-rings 36 and 38 mounted therebetween. Another O-ring 40 is mounted between top sub 10 and collet member 16. In the run-in position, the heads 20 are fully supported by mandrel 28 when surface 42 of mandrel 28 abuts surface 44 adjacent the heads 20. As seen in FIG. 2, when hydraulic pressure is applied by flow through bore 30, a force is exerted on taper 32 and upper end 34 due to the constricting effect and the presence of O-rings 36 and 38 and 40. Due to the unbalanced force on the mandrel 28, it is displaced downwardly, as shown in FIG. 2, such that surface 42 is removed by longitudinal translation away from surface 44. The fingers 18 become unsupported, as shown in FIG. 2. Thereafter, as shown in FIG. 3, the apparatus A is advanced into the fish 46. The fish 46 has an internal neck 48. Since the support for fingers 18 has been removed, they can flex radially inwardly toward surface 50 on the mandrel 28. Having attained this position shown in FIG. 3, the applied pressure to mandrel 28 through bore 30 is removed. This allows the spring 24 to return the mandrel 28 back to the position shown in FIG. 1. The support is thus returned to the collet heads 20, as shown in FIG. 4. As seen in FIG. 4, the heads 20 engage the fishing neck 48 while surface 42 of mandrel 28 fully supports surface 44 on fingers 18. The fish 46 is now ready to be lifted from the wellbore. If, for any reason, the operator decides to release the fish, the mere application of fluid pressure to the mandrel 28 by flow through bore 30 will once again displace the mandrel 28 downwardly to take away support for the collet heads 20. The operator simply applies pressure from the rigid or coiled tubing (not shown) while taking off the pulling force applied to the apparatus A and compressing spring 24 so as to reattain the position shown in FIG. 3. Thereafter, by simply maintaining the hydraulic pressure applied to the mandrel 28, the apparatus A can be detached from the fish by simply pulling upwardly.
Referring now to FIGS. 5-8, the detailed operation of the overshot of the preferred embodiment will be explained. As shown in FIG. 5, the overshot has a top sub 52 which has a thread 54. Thread 54 is used to attached rigid or coiled tubing (not shown). The top sub 52 has another thread 56 which is used to engage the collet assembly 58. Mounted over the collet assembly 58 is a mandrel 60. O-ring 62 seals between mandrel 60 and top sub 52. O-ring 64 seals between top sub 52 and collet assembly 58. A cavity 66 is formed between the collet assembly 58 and the mandrel 60. A lateral port or ports 68 connect bore 70 in collet assembly 58 to cavity 66. O-ring 72 is also mounted between collet assembly 58 and mandrel 60 to facilitate sealing variable volume cavity 66. The mandrel 60 has an internal shoulder 74 on which bears spring 76. Spring 76 also bears on shoulder 78 of collet assembly 58. Collet assembly 58 has a series of elongated fingers 80 which terminate at heads 82. In the run-in position shown in FIG. 5, the heads 82 are supported by surface 84 of mandrel 60. To facilitate latching onto the fish 86, a fishing neck 88 is provided.
In order to facilitate engagement of the fish 86, hydraulic pressure is applied through rigid or coiled tubing (not shown) and into bore 70. Bore 70 has a taper 90 which creates a smaller bore 92. As flow goes through smaller bore 92, it creates a backpressure in larger bore 70 which is in turn communicated through port 68 into variable volume cavity 66. As pressure builds up in cavity 66, the mandrel 60 is displaced, shown by comparing FIG. 6 to FIG. 5. Variable volume cavity 66 has enlarged in the view of FIG. 6 due to the additional pressure applied therein coupled with movement of mandrel 60 to compress spring 76. Since the top sub 52 is retained stationary by the coiled or rigid tubing (not shown) and the collet assembly 58 is securely mounted to the top sub 52 at thread 56, the lower end 94 of mandrel 60 moves longitudinally beyond the heads 82. When this occurs, surface 84 of mandrel 60, which is an annular member, no longer supports the fingers 80 at each one of their surfaces 96. While maintaining the hydraulic pressure that overcomes the force of spring 76 and advancing the apparatus A, as shown in FIG. 6, the collet heads 82 can flex outwardly to clear the fishing neck 88, as shown by comparing FIG. 6 to FIG. 7. It should be noted that the spring 76 remains in the compressed state in FIGS. 6 and 7 because the hydraulic pressure is maintained as the apparatus A is advanced. Having sufficiently advanced the apparatus A with hydraulic pressure applied to cavity 66, the hydraulic pressure is released allowing spring 76 to retract the mandrel 60 thus placing surface 84 back in a position to support the heads 82 at each surface 96. A simple upward pull on the apparatus A when attaining the position shown in FIG. 8 will allow removal of the fish 86. As with the spear, the overshot shown in FIGS. 5-8 can be released having grabbed the fish 86 by simply applying hydraulic pressure back into bore 70. This is accomplished by allowing flow through the restriction which is created by bore 92. By doing this, the apparatus A will be placed once again in the position shown in FIG. 7 where a mere upward pull is sufficient to allow release from the fish 86. This is because the heads 82 can flex radially outwardly toward surface 98 when shown in the position of FIG. 7 to either facilitate grabbing the fish 86 or releasing therefrom.
Those skilled in the art will appreciate that as to the overshot of FIGS. 5-8, the hydraulic force can be created in several different ways without departing from the spirit of the invention. The preferred mode is shown in FIGS. 5-8. In another mode, for example, the bore 92 may be eliminated completely so that the hydraulic pressure in cavity 66 can be created without any flow through the collet assembly 58. Alternatively, the components can be reconfigured so as to allow the use of annulus pressure as opposed to the pressure inside rigid tubing or coiled tubing (not shown) which is attached to top sub 52 to actuate the components as described. As one example, the lateral port 68 instead of communicating to bore 70 can be reconfigured to extend from cavity 66 radially outwardly through the mandrel 60 and into the annular space. To the extent it is possible to pressurize the annulus, the apparatus can be operated in that manner.
While a spring has been disclosed as the preferred embodiment for returning the mandrel 60 (see FIG. 8) or the mandrel 28 (see FIG. 4) to its run-in position other devices can be employed to put a biasing force on the mandrel without departing from the spirit of the invention. These components could include different types of springs or the application of available hydraulic pressure to obtain the requisite movement of the mandrel 60 or 28 to its run-in position shown in FIGS. 5 and 1, respectively.
It should be noted that the presence of O-rings 36, 38, and 40 facilitate the application of the applied hydraulic pressures due to the flow through bore 30 onto the mandrel 28 to facilitate its displacement against the opposing force of spring 24. Similarly, O-rings 62, 64, and 72 provide the necessary seals for variable volume cavity 66 so that when pressure is applied therein from flowthrough bores 70 and 92, the force applied to mandrel 60 overcomes the opposing force of spring 76.
Those skilled in the art will appreciate that the application of hydraulic force is used to displace a mandrel away from a collet or collets which it supports prior to bringing the apparatus A into engagement with the fish. Once the engagement is obtained, the fishing neck 48 of the fish 46 is fully supported by the heads 20 which are in turn backed up by the annular member mandrel 28. Similarly, in the case of the overshot of the present invention, the fishing neck 88 is fully supported by the heads 82 as backed up by the mandrel 60. The physical limits of pull that can be applied to a fish, such as 86, is limited only by the physical strength of the fingers 80 with their heads 82 when fully supported by the mandrel 60, as shown in FIG. 8. The same holds true for the spear in the position shown in FIG. 4.
As shown in FIG. 1, a sleeve 100 can be used and connected to collet member 16 at thread 102. Sleeve 100 can protect the collets against damage during handling. Such a sleeve is not used in the overshot, as illustrated in FIGS. 5-8, primarily for the reason that the annularly-shaped sleeve 60, which is on the exterior of the overshot, serves to protect the collet fingers 80 and heads 82.
Those skilled in the art will appreciate by examining FIGS. 4 and 8 that the weight of the fish 46 or 86 is fully supported by the collet heads 20 or 82 with radial support being provided by the mandrel 28 or 60, respectively. In the case of the spear of FIG. 1, the mandrel 28 radially supports the heads 20 from within, while in the overshot the parts are reversed and the mandrel 60 supports the heads 82 from outside.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the spirit of the invention.
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A fishing tool is disclosed which is responsive to hydraulic pressure to move away support for collets to allow the collects to deflect and make contact with the stuck object. Upon removal of the hydraulic force, the support for the collets is returned, preferably by a biasing spring, to its original position to lend support for the collets while the collets have engaged the stuck object. The object can then be retrieved to the surface. Application of further hydraulic force while the object engaged releases the support for the collects which allows the collets to disengage from the object. The process can be repeated to obtain successive releases and engagements with the stuck object without taking the fishing tool out of the wellbore.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods for rendering materials inflammable, and in particular, to methods for preparing fireproof feathers.
2. Prior Art
Although readily flammable, feathers and wool are used extensively as cushioning material for cushions, pillows, mattresses and the like, as well as for insulating material in jackets, sleeping bags, comforters and the like to retain body heat.
In the case of the wool, several processes have been proposed to impart fire resistant and fireproof properties. Japanese Patent Applications, Nos. 49-30879 and 50-17596 disclose a processes for preparing fireproof wool in which the ionized form of a metal element such as zirconium, titanium or the like is used as a fire-retarding agent. In this process, absorbtion of the metal ions into the wool is accomplished by ionic binding between metal ions and ionized portions of the wool. This process is not applicable to feathers, however, because the metal ions are poorly absorbed by feathers which contain a large proportion of non-polar amino-acids in comparison with wool.
A conventional process for fireproofing feathers exists in which a fire-retarding agent is applied to the surface of the feathers, for example, dimethylphosphonate oligomer. This process has the disadvantage that the fire-retarding agent tends to be washed away in subsequent processing. Additionally, this process tends to adversely affect the softness of the processed feathers.
SUMMARY OF THE INVENTION
In view of the above, it is an object of the present invention to provide a process for preparing fireproof feathers in which the feathers are treated with an acidic solution which imparts a positive charge to the surface of the feathers, and further, treating the feathers with an emulsified tetrabromophthalate derivative suspended in an aqueous solution of a water soluble compound, for example, zirconium fluoride or titanium fluoride, thus effecting fireproofing. In this way, fireproof feathers can be prepared easily and efficiently without adversely affecting the softness or other properties of the feathers.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following, a first preferred embodiment of the present invention will be described.
Feathers to be treated by the method of the present invention are first washed in water and collected until a suitable amount of feathers to be treated have been accumulated.
In the first step of the process according to the present invention, feathers are suspended in water in a ratio of from 1:10 to 1:50 by volume. The amount of water varies in proportion to the softness, and hence the density of the feathers. When the total volume of feathers to be treated (hereafter referred to as TV) are comprised of down by 80% or more, it is preferable that the ratio of feathers to water is approximately 1 to 30. On the other hand, if the down composition is less than 50% of TV, it is preferable that the ratio of feathers to water lie in the range of from 1:10 to 1:15.
For ionizing the surface of the feathers, the pH of the suspension is adjusted so as to be in the range of pH 2-4, using an acid selected from the group including hydrochloric acid, formic acid, sulfuric acid, acetic acid and the like. Because the isoelectric point of the surface of feathers is approximately pH 4.5, the surface of the feathers can be positively charged in this way.
In the second step of the process of the present invention, the water soluble compound such as zirconium fluoride or titanium fluoride, and the tetrabromophthalate derivative are added to the suspension of feathers.
In the present embodiment, the water soluble compound used is zirconium fluoride or titanium fluoride, or more preferably, potassium zirconium fluoride or the hydro-acid of titanium fluoride. A suitable amount of the compound is equivalent to 10 to 30% of total volume of feathers to be treated TV. Using lower or the higher amounts of the water soluble compound results in poor fire resistance properties for the treated feathers.
Following emulsification of the tetrabromophthalate derivative in water, this emulsified derivative is suspended in the suspension of feathers. A suitable amount of the derivative in the suspension is equivalent to 10 to 20%, more preferably 12 to 15% of TV.
In general, the surface of natural feathers is coated by hydrophobic substances such as lipids so that the feathers can readily shed water. The positive charged portions of the feathers to which the fire resistance imparting agent binds are masked by these hydrophobic substances. For this reason, in order to enhance the fire resistance properties of the treated feathers, these hydrophobic substances should be washed away from the surface of the feathers by incubating the feathers with a non-ionic detergent added to the suspension to maximize binding of the fire resistance imparting agent. Our investigation indicated that non-ionic detergents facilitated binding between the feathers and the fire resistance imparting agent. By contrast, our investigation also indicated that anionic detergents were not suitable because the anionic detergent competed with the fire resistance imparting agent for binding sites.
After addition of the water soluble compound and the tetrabromophthalate derivative, the suspension is gradually heated and incubated at 70°-100° C. over 30 minutes in an incubator. Following with the incubation, the feathers are drained, resuspended in water, washed and rinsed.
To further improve the fire resistance properties of the feathers treated as described above, after the above described steps, the feathers are resuspended in water in a ratio of from 1:10 to 1:50 by volume. Hydrofluorosilicic acid is added to the suspension and the resulting suspension is incubated at 50°-60° C. for 15-20 minutes. The amount of added hydrofluorosilicic acid is preferably equivalent to 2-5% of the total volume (TV). After the incubation, the feathers are drained, resuspended in water and washed. In spite of the repeated washings, the feathers treated by the process of the present invention continue to maintain their softness.
It is preferable that the amount of hydrofluorosilicic acid adding in the above described mixture is proportionate to the amount of the water soluble compound used previously, as shown in Table 1 below.
TABLE 1______________________________________Preferred ratio of hydrofluorosilicic acidand zirconium fluoride.zirconium fluoride (%) hydrofluorosilicic acid (%)______________________________________10 220 3.530 5______________________________________
Unless, otherwise stated, the expression "%" as used herein represents percentage of by weight. In addition, weights given for feathers (hereafter referred to as TW) are dry weights measured under conditions of 60% relative humidity at 20° C.
The invention will be more clearly understood by the following examples.
EXAMPLE 1:
(1) Sample preparation:
One kg of feathers (consisting of 70% down) were obtained from Chinese white geese. The obtained feathers were suspended in 30 liters of water at ambient temperature and the pH of the suspension was to 2.2 using 12% HCl.
(2) Chemical treatment:
Potassium zirconium fluoride and tetrabromophthalate derivative were added to the acidic suspension. The amount of potassium zirconium fluoride was equivalent to 20% of (TW). The amount of tetrabromophthalate derivative (Apex Flame Proof #160, Apex Chemical Corp., U.S.A.) was equivalent to 15% of TW and was emulsified prior to being added to the acidic suspension.
The acidic suspension was incubated at 75° C. for 30 minutes, after which the feathers were drained and resuspended in water at ambient temperature. The feathers were washed in the water, drained and allowed to dry. The dried feathers were divided into samples, after which each sample was subjected to a burning test or a re-forming test as described below.
(3) Burning test:
The burning test was accomplished by a conventional method which was established by the Nippon Bosai Kyokai (Japanese association responsible for certifying fireproof products).
An sample of 2 g of the feathers was stuffed into a basket (20 mm H×150 mm D×100 mm W, made of stainless steel with a fine mesh of approximately 0.2-0.4 mm in diameter).
Before subjecting the feathers to the burning test, the feathers and basket were incubated at 50°±2° C. for 24 hours in a dry atmosphere. After the incubation, the feathers and basket were transferred into a desiccator containing anhydrous silica gel. After 2 hours in the desiccator, the feathers and basket were placed in a burning test chamber in which the basket was fixed and inclined at an angle of 45 degrees.
In the basket, a solid fuel (0.15 g of hexamethylenetetramine) was fixed and localized 45 cm above the central part of the base of the basket. The solid fuel was then ignited and allowed to burn, after which the depth to which the sample was charred was measured. The test was repeated on two other aliquots of the feathers, the results of which are shown in Table 2 below.
In the burning test thus described, acceptable fire resistant properties are defined such that the maximum charring for any sample must be less than 120 mm, and the average charring for multiple samples must be less than 100 mm. On this basis, the feathers treated as described in Example 1 was determined to be acceptable.
(4) Re-forming test:
The Re-forming test was performed as described below according to the conventional method of the Feather Product Association under the auspices of the Ministry of International Trade and Industry of Japan.
Prior to the test, a sample of the feathers was subjected to a vacuum, after which the moisture content of the sample was allowed to equilibrate within an atmosphere having 65% relative humidity at 20° C. The sample thus treated was then stuffed into a cylindrical container and a standard weight was placed over the feathers for 2 minutes, after which the weight was removed. The height of the feathers was then measured and compared with the height prior to placing the weight. This test was repeated using three samples of the treated feathers. The results are shown in Table 3.
(5) Results:
As shown in Tables 2 and 3, the results of these tests indicate that the fireproof feathers of Example 1 prepared according to the method of the present invention maintained their fire-resistance properties and bulk after several washings.
EXAMPLE 2
The same procedures as described for Example 1 were repeated using feathers having a down content of 70%. The results of the re-forming test are shown in Table 3. These results indicated that the fireproof feathers of Example 2 prepared according to the method of the present invention maintained their bulk after several washings.
EXAMPLE 3
The same procedures as described for Example 1 were repeated using feathers having a down content of 90%. The results of the re-forming test are shown in Table 3. These results indicated that the fireproof feathers of Example 3 prepared according to the method of the present invention maintained their bulk after several washings.
EXAMPLE 4
The same procedure as described for Example 1 was repeated except that potassium titanium fluoride was added to the solution rather than potassium zirconium fluoride. The amount of potassium titanium fluoride is equivalent to 12% of TW. The results of the burning test and the re-forming test are shown in tables 2 and table 3, respectively.
The results indicated that the fireproof feathers of Example 4 treated according to the method of the present invention maintained their fire resistance properties and bulk after several washings. However, the feathers were discolored to pale yellow during the process according to this example.
EXAMPLE 5
The same procedure as in Example 4 were repeated except that the sample had a down content of 50%. The results of the re-forming test are shown in Table 3.
The results indicated that the fireproof feathers of Example 5 treated according to the method of the present invention maintained their bulk after several washings.
EXAMPLE 6
The same procedure as in Example 4 were repeated except that the sample had a down content of 90%. The results of the re-forming test are shown in Table 3.
The results indicated that the fireproof feathers of Example 6 treated according to the method of the present invention maintained their bulk after several washings.
EXAMPLE 7
One kg of feathers (consisting of 70% down) were obtained from Chinese white geese. The obtained feathers were suspended in 30 liters of water at ambient temperature and the pH of the suspension was to 2.2 using 12% HCl.
Potassium zirconium fluoride and tetrabromophthalate derivative were added to the acidic suspension. The amount of potassium zirconium fluoride was equivalent to 20% of TW. The amount of tetrabromophthalate derivative (Apex Flame Proof #160, Apex Chemical Corp., U.S.A.) was equivalent to 15% of TW and was emulsified prior to being added to the acidic suspension.
The acidic suspension was gradually heated to 75° C. and was incubated at that temperature for 30 minutes, after which the feathers were drained and resuspended in water at ambient temperature. The feathers were then washed in the water, drained and allowed to dry.
The washed feathers were resuspended in 30 liters of water at the normal temperature. An amount of hydrofluorosilicic acid equivalent to TW was added to the suspension, after which the resulting suspension was heated to 60° C., and maintained at that temperature for 20 min. Afterwards, the feathers were washed in water, drained and allowed to dry. The dried feathers were divided into samples, after which each sample was subjected to a burning test or a re-forming test as described for Example 1. The results of the burning test and the re-forming test are shown in Tables 2 and Table 3, respectively.
The results indicated that the fireproof feathers of Example 7 prepared according to the method of the present invention demonstrated improved fire resistance properties and bulk retention compared with the feathers processed in example 1.
EXAMPLE 8
The same procedures as described for Example 7 were repeated using feathers having a down content of 50%. The results of the re-forming test are shown in Table 3. These results indicated that the fireproof feathers of Example 2 prepared according to the method of the present invention maintained their bulk after several washings.
EXAMPLE 9
The same procedures as described for Example 7 were repeated using feathers having a down content of 90%. The results of the re-forming test are shown in Table 3. These results indicated that the fireproof feathers of Example 9 prepared according to the method of the present invention maintained their bulk after several washings.
CONTROL EXPERIMENT 1
An 8% dimethylphosphonate oligomer (Fran TF-2000, Yamato Chemical Industry Co., Japan) solution was prepared by solving the oligomer in 30 liters of water. One kg of feathers (consisting of 70% down) obtained from Chinese white geese were suspended in the solution and the resulting suspension was incubated at ambient temperature for 15 minutes. The feathers were then drained and resuspended in water and washed. The washed feathers were then drained and dried in an atmosphere of 50% relative humidity, after which they were subjected to the burning test and the re-forming test described for Example 1.
The results indicated that the fireproof feathers of control experiment 1 had poor fire resistance properties and bulk retention after washing.
CONTROL EXPERIMENT 2
The same procedures as in Control experiment 1 were repeated using feathers having a down content of 50%. The results obtained are shown in tables 2 and 3. The results indicated that the fireproof feathers of control experiment 2 had poor fire resistance properties and bulk retention after washing.
CONTROL EXPERIMENT 3
The same procedures as in Control experiment 1 were repeated using feathers having a down content of 90%. The results obtained are shown in tables 2 and 3. The results indicated that the fireproof feathers of control experiment 3 had poor fire resistance properties and bulk retention after washing.
CONTROL EXPERIMENT 4
One kg of feathers (consisting of 70% down) were obtained from Chinese white geese. The obtained feathers were suspended in 30 liters of water at ambient temperature and the pH of the suspension was to 2.2 using 12% HCl.
An amount of tetrabromophthalate derivative (Apex Flame Proof #160, Apex Chemical Corp., U.S.A) equivalent to 15% of TW and was emulsified and then added to the acidic suspension. The acidic suspension was heated to 75° C. and was incubated at that temperature for 30 minutes, after which the feathers were drained and resuspended in water at ambient temperature. The feathers were then washed in the water, drained and allowed to dry.
The dried feathers were divided into samples, after which each sample was washed five times and then subjected to the re-forming test as described for Example 1. The results of the re-forming test are shown in Table 3.
The results indicated that the fireproof feathers of control experiment 4 had poor bulk retention properties after washing.
CONTROL EXPERIMENT 5
One kg of feathers (consisting of 70% down) were obtained from Chinese white geese. The obtained feathers were suspended in 30 liters of water at ambient temperature and the pH of the suspension was to 2.2 using 12% HCl.
An amount of potassium zirconium fluoride equivalent to 20% of TW was disolved in the acidic suspension. The acidic suspension was heated to 75° C. and was incubated at that temperature for 30 minutes, after which the feathers were drained and resuspended in water at ambient temperature. The feathers were then washed in the water, drained and allowed to dry.
The dried feathers were divided into samples, after which each sample was washed five times and then subjected to the re-forming test as described for Example 1. The results of the re-forming test are shown in Table 3.
The results indicated that the fireproof feathers of control experiment 5 had poor bulk retention properties after washing.
CONTROL EXPERIMENT 6
One kg of feathers (consisting of 70% down) were obtained from Chinese white geese. The obtained feathers were suspended in 30 liters of water at ambient temperature and the pH of the suspension was to 2.2 using 12% HCl.
An amount of potassium titanium fluoride equivalent to 12% of TW was disolved in the acidic suspension. The acidic suspension was heated to 75° C. and was incubated at that temperature for 30 minutes, after which the feathers were drained and resuspended in water at ambient temperature. The feathers were then washed in the water, drained and allowed to dry.
The dried feathers were divided into samples, after which each sample was washed five times and then subjected to the re-forming test as described for Example 1. The results of the re-forming test are shown in Table 3.
The results indicated that the fireproof feathers of control experiment 6 had poor bulk retention properties after washing.
TABLE 2______________________________________The results of the burning assay The length of a carbonied part of the sample which is subjected to one of the treatments of followings:Sample fire- dry- washing washingNo. preventing cleaning (40° C.) (60° C.)______________________________________Example 1. 1 6.6 7.5 7.8 8.6 2 7.2 6.8 7.4 9.4 3 6.8 6.5 6.5 8.8Example 4. 4 6.2 6.7 5.5 8.8 5 6.0 6.4 6.5 8.5 6 6.4 6.2 6.8 7.8Example 7. 7 5.5 6.0 5.3 6.5 8 5.8 6.2 5.5 7.0 9 6.0 6.0 4.8 8.0Control 1. 10 7.2 8.6 * * 11 8.5 7.8 * * 12 7.8 9.3 * *Control 4. 13 5.6 8.3 * * 14 6.0 7.8 * * 15 7.3 8.1 * *Control 5. 16 9.8 9.2 9.2 11.6 17 10.0 6.2 7.4 9.8 18 6.6 6.3 6.5 12.1Control 6. 19 6.8 7.2 8.3 10.0 20 7.2 7.3 8.7 11.8 21 7.8 8.0 7.8 11.5______________________________________ *the feathers were all burned.
TABLE 3______________________________________The results of the re-forming assay Resulting height of the stuffed feathers after the weighing (cm) before the treatment after the treatment______________________________________Example 1. 11.2 11.0Example 2. 8.5 8.4Example 3. 14.5 14.6Example 4. 11.2 11.1Example 5. 8.5 8.5Example 6. 14.8 14.7Example 7. 11.2 11.0Example 8. 8.5 8.3Example 9. 14.8 14.5Control 1. 11.2 8.7Control 2. 8.5 6.6Control 3. 14.8 11.5______________________________________
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The present inventon relates to methods for rendering materials inflammable, and in particular, to methods for preparing fireproof feathers.
According to the present invention, a process for preparing fireproof feathers comprising steps of: (a) suspending a predetermined amount of feathrs in water to make a suspension of the feathers; (b) adjusting the pH of the suspension to lie within the range of pH 2-4 with acid to make a acidic suspension; (c) adding tetrabromophthalate derivative which is emulsified in water in advance and a water soluble compound to the acidic suspension, where the water soluble compound is preferably selected from the group including zirconium fluoride and titanium fluoride, and more preferably from the group including potassium zirconium fluoride and the hydro-acid of titanium fluoride; (d) resuspending and wahsing the feathers in water; and (e) drying the thus processed feathers.
In this way, fireproof feathers can be prepared easily and efficiently without adversely affecting the softness or other properties of the feathers.
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CROSS REFERENCE TO RELATED PATENT APPLICATION
This patent application is related to commonly owned U.S. patent application Ser. No. 09/153,211; filed Sep. 14, 1998 still pending; entitled “Method and System for Implementing Intelligent Distributed Input-Output Processing as a Software Process in a Host Operating System Environment” by Thomas J. Bonola, and is hereby incorporated by reference for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a computer system using intelligent input-output (I 2 O), and more particularly, to a multi-processor computer system using at least one of its processors for processing I 2 O transactions.
2. Description of the Related Technology
Use of computers, especially personal computers, in business and at home is becoming more and more pervasive because the computer has become an integral tool of most information workers who work in the fields of accounting, law, engineering, insurance, services, sales and the like. Rapid technological improvements in the field of computers have opened up many new applications heretofore unavailable or too expensive for the use of older technology mainframe computers. These personal computers may be used as stand-alone workstations (high end individual personal computers) or linked together in a network by a “network server” which is also a personal computer which may have a few additional features specific to its purpose in the network. The network server may be used to store massive amounts of data, and may facilitate interaction of the individual workstations connected to the network for electronic mail (“E-mail”), document databases, video teleconferencing, whiteboarding, integrated enterprise calendar, virtual engineering design and the like. Multiple network servers may also be interconnected by local area networks (“LAN”) and wide area networks (“WANs”).
A significant part of the ever-increasing popularity of the personal computer, besides its low cost relative to just a few years ago, is its ability to run sophisticated programs and perform many useful and new tasks. Personal computers today may be easily upgraded with new peripheral devices for added flexibility and enhanced performance. A major advance in the performance of personal computers (both workstation and network servers) has been the implementation of sophisticated peripheral devices such as video graphics adapters, local area network interfaces, SCSI bus adapters, full-motion video, redundant error checking and correcting disk arrays, and the like. These sophisticated peripheral devices are capable of data transfer rates approaching the native speed of the computer system microprocessor central processing unit (“CPU”). The peripheral devices' data transfer speeds are achieved by connecting the peripheral devices to the microprocessor(s) and associated system random access memory through high speed information (data and address) buses.
The computers system has a plurality of information buses such as a host bus, a memory bus, at least one high speed local peripheral expansion bus, and other peripheral buses such as the Small Computer System Interface (“SCSI”), Extension to Industry Standard Architecture (“EISA”), Industry Standard Architecture (“ISA”), and Peripheral Component Interconnect (“PCI”). The microprocessor(s) of the computer system communicates with main memory and with the peripherals that make up the computer system over these various buses. The microprocessor(s) communicates to the main memory over a host bus to memory bus bridge. The peripherals, depending on their data transfer speed requirements, are connected to the various buses which are connected to the microprocessor host bus through bus bridges that detect required actions, arbitrate, and translate both data and addresses between the various buses.
A widely used peripheral expansion bus that may be used in IBM-compatible PCs, Apple computers and RISC workstations is a high speed expansion bus standard called the “Peripheral Component Interconnect” or “PCI.” The PCI bus standard is microprocessor-independent and has been embraced by a significant number of peripheral hardware manufacturers and software programmers. A more complete definition of the PCI local bus may be found in the PCI Local Bus Specification, revision 2.1; PCI/PCI Bridge Specification, revision 1.0; PCI System Design Guide, revision 1.0; and PCI BIOS Specification, revision 2.1, the disclosures of which are hereby incorporated by reference. These PCI specifications are available from the PCI Special Interest Group, P.O. Box 14070, Portland, Oreg. 97214.
Computer system peripheral hardware devices, i.e., hard disks, CD-ROM readers, network interface cards, video graphics controllers, modems and the like, may be supplied by various hardware vendors. These hardware vendors must supply software drivers for their respective peripheral devices used in each computer system even though the peripheral device may plug into a standard PCI bus connector. The number of software drivers required for a peripheral device multiplies for each different computer and operating system. In addition, both the computer vendor, operating system vendor and software driver vendor must test and certify the many different combinations of peripheral devices and the respective software drivers used with the various computer and operating systems. Whenever a peripheral device or driver is changed or an operating system upgrade is made, retesting and recertification may be necessary.
The demand for peripheral device driver portability between operating systems and host computer systems, combined with increasing requirements for intelligent, distributed input-output (“I/O”) processing has led to the development of an “Intelligent Input/Output” (“I 2 O”) specification. The basic objective of the I 2 O specification is to provide an I/O device driver architecture that is independent of both the specific peripheral device being controlled and the host operating system. This is achieved by logically separating the portion of the driver that is responsible for managing the peripheral device from the specific implementation details for the operating system that it serves. By doing so, the part of the driver that manages the peripheral device becomes portable across different computer and operating systems. The I 2 O specification also generalizes the nature of communication between the host computer system and peripheral hardware, thus providing processor and bus technology independence.
The I 2 O specification, entitled “Intelligent I/O (I 2 O) Architecture Specification,” Draft Revision 1.5, dated March 1997, is available from the I 2 O Special Interest Group, 404 Balboa Street, San Francisco, Calif. 94118; the disclosure of this I 2 O specification is hereby incorporated by reference.
FIG. 1 illustrates a schematic block diagram of a multi-processor computer system. The computer system is generally indicated by the numeral 100 and comprises central processing units (“CPUs”) 102 , core logic 104 , system random access memory (“RAM”) 106 , a video graphics controller 110 , a local frame buffer 108 , a video display 112 , a PCI/SCSI bus adapter 114 , a PCI/EISA/ISA bridge 116 , a PCI/IDE controller 118 , and PCI/PCI bus bridges 124 a, 124 b. The local frame buffer 108 connects to a video graphics controller 110 which interfaces and drives a video display 112 . Single or multilevel cache memory (not illustrated) may also be included in the computer system 100 according to the current art of microprocessor computer systems.
The CPUs 102 are connected to the core logic 104 through a CPU host bus 103 . The system RAM 106 is connected to the core logic 104 through a memory bus 105 . The core logic 104 includes a host-to-PCI bridge between the host bus 103 , the memory bus 105 and a first PCI bus 109 . The local frame buffer memory 108 , and PCI/PCI bridges 124 a, 124 b are connected to the first PCI bus 109 . The PCI/SCSI bus adapter 114 and PCI/EISA/ISA bridge 116 are connected to the PCI/PCI bridge 124 a through a second PCI bus 117 . The PCI/IDE controller 118 and a network interface card (“NIC”) 122 are connected to the PCI/PCI bridge 124 b through a third PCI bus 115 . Some of the PCI devices such as the local frame buffer 108 /Video controller 110 and NIC 122 may plug into PCI connectors on the computer system 100 motherboard (not illustrated). PCI connectors 160 and 162 are illustrated connected to the PCI bus 117 and are for plugging PCI device cards into the computer system 100 . Three PCI buses 109 , 117 and 115 are illustrated in FIG. 1, and may have logical PCI bus numbers of zero, one and two, respectively.
Hard disk 130 and tape drive 132 are connected to the PCI/SCSI bus adapter 114 through a SCSI bus 111 . The NIC 122 is connected to a local area network 119 . The PCI/EISA/ISA bridge 116 connects over an EISA/ISA bus 113 to a ROM BIOS 140 , non-volatile random access memory (NVRAM) 142 , modem 120 , and input-output controller 126 . The modem 120 connects to a telephone line 121 . The input-output controller 126 interfaces with a keyboard 146 , real time clock (RTC) 144 , mouse 148 , floppy disk drive (“FDD”) 150 , and serial/parallel ports 152 , 154 . The EISA/ISA bus 113 is a slower information bus than the PCI bus 109 , but it costs less to interface with the EISA/ISA bus 113 .
When the computer system 100 is first turned on, start-up information stored in the ROM BIOS 140 is used to begin operation thereof. Basic setup instructions are stored in the ROM BIOS 140 so that the computer system 100 can load more complex operating system software from a memory storage device such as the disk 130 . Before the operating system software can be loaded, however, certain hardware in the computer system 100 must be configured to properly transfer information from the disk 130 to the CPU 102 . In the computer system 100 illustrated in FIG. 1, the PCI/SCSI bus adapter 114 must be configured to respond to commands from the CPUs 102 over the PCI buses 109 and 117 , and transfer information from the disk 130 to the CPU 102 via buses 117 , 109 and 103 . The PCI/SCSI bus adapter 114 is a PCI device and remains platform independent. Therefore, separate hardware independent commands are used to setup and control any PCI device in the computer system 100 . These hardware independent commands, however, are located in a PCI BIOS contained in the computer system ROM BIOS 140 . The PCI BIOS is firmware that is hardware specific but meets the general PCI specification. Plug and play, and PCI devices in the computer system are detected and configured when a system configuration program is executed. The results of the plug and play, and PCI device configurations are stored in the NVRAM 142 for later use by the startup programs in the ROM BIOS 140 and PCI BIOS which configure the necessary computer system 100 devices during startup. After startup of the computer system 100 , the operating system software including the I 2 O software, according to the I 2 O Specification incorporated by reference above, is loaded into the RAM 106 for further operation of the computer system 100 . An I/O processor, a hardware device, called an I/O Processor (“IOP”) 202 , is utilized in conjunction with the I 2 O Specification, as more fully described hereinbelow.
FIG. 2 illustrates a functional block diagram of the I 2 O specification, which divides the peripheral drivers into two parts: 1) the Operating System Services Module (“OSM”) 212 which interfaces with the host operating system (“OS”) 200 ; and 2) the Device Driver Module (“DDM”) 204 that executes on an IOP 202 and which interfaces with a particular hardware device, media or server ( 206 ) that the driver must manage. All of the modules are capable of communicating with each other across a common communication layer 208 . As defined in the I 2 O Specification, the IOP 202 is a platform (node) consisting of a processor, memory, and I/O devices that are managed independently from other processors within the system for the sole purpose of processing I/O transactions.
FIG. 3 illustrates the basic software architecture of an I 2 O compliant system. A DDM can be a hardware driver module (“HDM”) 308 , an Intermediate Service Module (“ISM”) 306 , or both. These two modules interface with other components via a communication system comprised of two parts: 1) message layers 300 and 304 which operate in conjunction with the host operating system 200 and the IOP 202 , respectively, to set up a communications session between parties (OSM-DDM or DDM-DDM); and 2) a transport layer 302 which defines how the two parties will share information. Much like a standard communications protocol, the message layers 300 , 304 reside on the transport layer 302 .
The communications model defined in the I 2 O specification, when combined with an execution environment and configuration interface, provides the DDM 204 with a host-independent interface. The modules are able to communicate without knowledge of the underlying bus architecture or computer system topology. Messages form a meta-language for the modules to communicate in a manner that is independent of the bus topology and host OS interfaces. The communications model for the I 2 O architecture is a message passing system. The I 2 O communication model is analogous to a connection oriented networking protocol, such as TCP/IP, in which the two parties interested in exchanging messages utilize the communication layer 208 to set up a connection and exchange data and control.
FIG. 4 illustrates the basic I 2 O communication model. When the OSM 212 is presented with a request from the host OS 200 , it translates the request into an I 2 O request ( 400 ) and invokes the host's Message Transport layer 402 to deliver the message. The OSM Message Transport layer 402 removes the first free message frame (MFA) 404 from the remote IOP's ( 202 ) inbound free list 408 , places the request information into the MFA 404 and posts the inbound message 406 in the remote IOP's ( 202 ) inbound post queue 408 . The remote IOP's ( 202 ) Message Transport layer 414 removes the message 412 from the inbound post queue 408 , extracts the request information from the inbound MFA 412 , returns the now-free MFA 412 to the Inbound free list 408 , and dispatches the posted request 416 to the appropriate DDM 204 for processing,.
Upon completion of the request, the DDM 204 issues a response 420 that notifies the IOP 202 to dispatch the result back to the OSM 212 by sending a message through the I 2 O Message Layer. The remote IOP's Message Transport Layer 414 removes a free MFA 422 from the outbound free list 426 , places the response data 420 into the MFA 424 , posts the MFA 424 into the outbound post list 426 , and notifies the OSM 212 that a response is waiting. The host Message Transport Layer 402 reads the MFA 430 from the outbound post list 426 , removes the response data 432 from the MFA, returns (writes) the now-free MFA 428 to the outbound free list 426 , and returns the response 432 to the OSM 212 . The OSM 212 behaves just like any other device driver in the host OS 200 . The OSM 212 interfaces to host-specific Application Programming Interfaces (“APIs”), translating them to a neutral message-based format that is then sent to a DDM 204 for processing.
Referring now to FIG. 5, operations flow of a standard I 2 O-compliant system is illustrated. The OS 200 of the host CPU(s) 102 issues an I/O request 500 . The OSM 212 accepts the request 500 and translates it (step 502 ) into a message 504 addressed to the target DDM 204 running on the IOP 202 . The OSM 212 invokes the host Message Transport layer 402 to deliver the message. The host Message Transport layer 402 queues the message 510 by copying it (step 508 ) across the PCI buses 109 and 117 into a message frame buffer on the remote IOP 202 . The remote IOP 202 Message Transport 414 posts the message 514 to the event queue (step 512 ) of the DDM 204 . The DDM 204 then processes the request (step 516 ).
After processing the message and satisfying the request (step 516 ), the DDM 204 builds a reply 520 (step 518 ), addresses the reply 520 to the initiator of the request, and invokes the remote IOP 202 Message Transport layer 414 to send the reply 524 to the initiator. The remote IOP Message Transport layer 414 queues the reply 524 by copying it (step 522 ), across the PCI buses 109 , 117 , into a message frame buffer residing at the host's Message Transport layer 402 . The remote IOP 202 then alerts the host's Message Transport layer 402 that a message is ready for delivery. The host's Message Transport layer 402 invokes the OSM's 212 message handler (step 526 ) which retrieves the OS 200 I/O request 532 from the message in order to complete the OS I/O request (step 530 ). Finally, the request itself is returned to the OS 200 (step 528 ).
Referring now to FIG. 6, a schematic block diagram of a standard I 2 O architecture is illustrated. The DDMs 204 a and 204 b are the lowest level modules in the I 2 O environment, encapsulating the software which is specific to a particular controller and the associated peripheral devices (LAN 206 a and disk 206 b ), in essence, providing an abstract device driver for the I 2 O environment. The DDM translation layer is unique to each individual peripheral device and vendor, and supports a range of operating types, including synchronous, asynchronous request, event-driven, and polled. The DDMs 204 a and 204 b, which execute on the IOP 202 , are managed by the I 2 O real-time input-output operating system (“iRTOS”) 608 , which provides the necessary support for the operating system processes and bus-independent execution. DDMs in general may therefore be designed in a manner which minimizes changes when moving from one computer system hardware platform to another.
In order to support the I 2 O device model, the I 2 O specification defines a hardware architecture which uses a single host processor (which may consist of multiple processors 102 a, 102 b and 102 c on a single host bus) and an intelligent I/O subsystem containing one or more physical hardware I/O processors 202 . The I/O subsystem 202 has its own operating system 608 , local memory (ROM and RAM) and local I/O bus(es) (not illustrated). The dedicated I/O processor(s) 202 may be located on a plug-in feature card, generally a PCI device card. Special memory must also be provided for each dedicated I/O processor so that both private and shared memory are available. The private memory is only used by the associated I/O processor 202 , but the shared memory must be available to all of the computer system resources.
The shared memory, through appropriate memory address translators, is the vehicle through which different I/O processors and the host processor communicate with one another through the message and transport layers. Messages sent to the IOP 202 are allocated from the inbound free list 406 and placed in the inbound post queue 408 located at an address equal to the PCI card's base address plus 0x40 (hexadecimal) ( 600 ). Messages from the IOP 202 to the OSM 212 are allocated from the outbound free list 604 and placed in an outbound post queue 606 located at an address equal to the PCI card's base address plus 0x44 ( 602 ).
According to the I 2 O Specification, these I/O processors (IOP 202 ) require a separate computer subsystem complete with its own dedicated microprocessor, memory, internal information bus(es) and printed circuit board real estate. This is neither cost effective nor practical for manufacturing general use computer systems having an optimal performance to cost ratio. In addition, legacy computer systems having only ISA and EISA buses could not utilize newer OS and peripheral devices running under the I 2 O specification because of their lack of a PCI bus(es).
What is needed is a method and system for implementing intelligent distributed I/O processing, such as I 2 O, in a multi-processor computer system without requiring special hardware for a dedicated I/O processor subsystem.
SUMMARY OF THE INVENTION
The present invention provides a software program used in conjunction with a standard general purpose multi-processor computer system as a means of implementing an I 2 O-compliant IOP without requiring a special hardware IOP processor embedded on a PCI device card. The present invention utilizes software modules inserted into the operating system during computer system initialization, thereby causing the OSM of the OS to operate as if it is communicating with a physical IOP installed on a PCI bus, but instead is utilizing at least one of the multi-processors as a virtual input-output processor (hereinafter “V-IOP”) of the computer system. These software modules intercept messages to and from the DDMs and assign them to the V-IOP, thus making operation of the computer system with the present invention indistinguishable from messages that would have been processed by a hardware configured IOP in the computer system.
Therefore, the present invention solves the technical problem of implementing I 2 O functionality in a computer system without requiring the added cost and complexity of a special hardware I 2 O compliant IOP device. The present invention also solves the technical problem of implementing I 2 O functionality on systems that could not otherwise utilize the I 2 O standard, such as non-PCI bus configured legacy computers.
Thus, the present invention provides a method and system for implementing intelligent distributed input-output processing in a multi-processor computer system by allocating one or more of the multi-processors of the host computer system as an I 2 O-compliant IOP running the DDMs and operating under the I 2 O communications protocols. The DDMs may use system memory which utilizes cache coherency hardware provided by the host multi-processor computer system. The present invention may store I 2 O message frames in the host main memory without traversing over the I/O bus(es) unless needed by a target device. In addition, the present invention enables I 2 O functionality on currently installed computers without requiring hardware upgrades to a dedicated hardware I/O processor subsystem, thus enabling non-PCI bus configured computers to take advantage of new OS and peripheral hardware utilizing the I 2 O specification.
Other and further features and advantages will be apparent from the following description of presently preferred embodiments of the invention, given for the purpose of disclosure and taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a typical computer system;
FIG. 2 is a schematic block diagram of the typical I 2 O split driver model;
FIG. 3 is a schematic block diagram of the I 2 O software architecture;
FIG. 4 is a schematic block diagram of the I 2 O communication model;
FIG. 5 is a schematic block diagram of the standard I 2 O I/O operations flow.
FIG. 6 is a schematic block diagram of the I 2 O standard architecture;
FIG. 7 is a schematic block diagram of the I 2 O-compliant software architecture according to the present invention;
FIG. 8 is a flow diagram showing the process of initializing and starting the software of the present invention;
FIG. 9 is a flow diagram showing the initialization process for the V-IOP Driver;
FIG. 10 is a flow diagram showing the launching of the V-IOP;
FIG. 11 is a flow diagram showing the startup of the V-IOP Driver;
FIG. 12 is a flow diagram showing the Target CPU Initialization;
FIG. 13 is a flow diagram showing the Target CPU Startup;
FIG. 14 is a flow diagram showing the method of handling interrupt requests;
FIG. 15 is a flow diagram showing the creation of the List of Active Event Queues; and
FIG. 16 is a flow diagram showing the allocation of resource required to implement the V-IOP iRTOS.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a system and method for implementing an I 2 O-controlled IOP system using general computer system hardware controlled by software. Although the following describes the implementation of the present invention on an I 2 O-compliant system, it will be understood by those of ordinary skill in the art that the present invention can work with other input-output schemes besides the I 2 O scheme. The present invention comprises: (1) a system driver (V-IOP driver) program capable of intercepting and redirecting input-output related messages and capable of handling interrupts; (2) a real-time operating system program (V-IOP OS) that provides communication between I 2 O-controlled devices and the operating system module (OSM) that contains the V-IOP driver; and (3) an installation is program that installs the V-IOP driver and the V-IOP OS image onto the computer system and designates the number of CPUs that are to be devoted to input-output processing.
A CPU that runs under the V-IOP OS is called a V-IOP (“virtual input-output processor”). More than one CPU can be operated under the V-IOP OS so that multiple I/O commands can be processed in parallel. The V-IOP OS is not intended to be run under the bootstrap processor (i.e., the CPU that is running the host OS). Consequently, the number of V-IOPs possible on any computer system is the number of CPUs less one.
When an interrupt signal emanates from, or is sent to, the host operating system (specifically, the OSM), the V-IOP driver is invoked. The V-IOP driver interprets the intercepted signals and, if the signal is associated with an I 2 O-controlled device, forwards the signal to one of the V-IOPs. The V-IOP OS, which contains a special wrapper for the I 2 O-compliant real-time input-output operating system executable, then processes the forwarded signal. This arrangement allows multiple input-output signals to be processed in parallel and does not require a dedicated processor on a separate board.
Installation of the Software onto the Computer System
The software of the present invention is installed conventionally onto the computer system. In the preferred embodiment of the present invention, there are two electronic files: a V-IOP driver that is loaded by the host operating system, and a V-IOP executable image that runs on one or more of the multiprocessors. An installation program is provided to facilitate the setup of the two electronic files on the computer system. The installation program prompts the computer system operator to identify the folder(s) where the two files (the V-IOP driver and the V-IOP OS) are to be stored and requests the operator to designate the number of CPUs that are to be devoted to input-output processing. The installation program then copies the two files to the appropriate directory and, for example, modifies the system registry or otherwise stores information to reflect the number of CPUs that are to be devoted to the software of the present invention.
It should be understood that the number of CPUs originally designated during the installation phase may not be the number actually designated upon system startup. Problems could arise. For example, one of the multiprocessors originally allocated to the present invention may have been removed. For this reason, upon booting of the computer system, the V-IOP driver of the present invention counts the number of CPUs present on the computer system and allocates either the number originally requested, or as many CPU's as are available less one (that is the bootstrap processor (BSP)).
Configuration of the Apparatus
An overview of the software architecture of the present invention is illustrated in FIG. 7 . As in a standard I 2 O compliant system, the input-output driver 211 is an operating system module (OSM) that executes under the control of the host OS 200 . Unlike the prior art implementation of I 2 O, which requires a separate, special hardware IOP board 202 (FIGS. 1 and 6) connected to the PCI bus 117 (FIG. 1) in order to execute a standard iRTOS (not shown) and associated DDMs ( 204 a and 204 b ), the present invention shown in FIG. 7 allocates one or more CPUs 102 d to the task of acting as a virtual IOP (“V-IOP”) 702 . Executing on the V-IOP 702 is the V-IOP OS 704 in the form of a special wrapper 704 that contains an iRTOS 710 with I 2 O functionality as well as the associated DDMs ( 204 a and 204 b ). The wrapper 704 presents an I 2 O iRTOS personality to the DDM's, i.e., the DDM's within the wrapper 704 cannot distinguish the iRTOS 710 in the wrapper 704 from a standard I 2 O iRTOS running on a separate IOP running on the host OS. The wrapper 704 is described more fully in commonly owned U.S. patent application Ser. No. 09/152,728; filed Sep. 23, 1998 still pending; entitled “Method and Apparatus for Providing Symmetric Multiprocessing in an I 2 O Real-Time Operating System” by Thomas J. Bonola, and is hereby incorporated by reference.
The present invention also differs from the prior art in that it allocates memory for the V-IOP 702 within the computer system RAM 106 (FIG. 7) rather than from dedicated memory on a physical IOP board 202 . Yet another way in which the present invention differs from the prior art is that, although it can communicate with devices connected to a PCI bus as in the prior art, it can also communicate with hardware I/O devices 206 a and 206 b connected to non-PCI buses, such as the EISA/ISA bus 113 (FIG. 1) commonly found in legacy computer systems. Finally, the present invention differs from the prior art in that all messages between the input-output operating system module (“OSM”) 212 (which contains the standard IOP driver 211 ), and the iRTOS 710 within the wrapper 704 that is executing on the V-IOP 702 , are sent over the host bus 103 via the I 2 O message handlers 706 in the V-IOP driver 700 .
The V-IOP driver 700 also contains a V-IOP startup routine 708 that is used to allocate a CPU, load the V-IOP OS onto that CPU, perform a fix up procedure to link the V-IOP OS to the V-IOP driver, and then launch (i.e. restart) that CPU so that it will operate under the V-IOP OS to form a V-IOP.
Initalization and Starting of the Software
FIG. 8 is a flow diagram showing the overall process of initializing and starting the software of the present invention. Specific elements of the initialization process are explained more fully elsewhere in the description and other figures. For example, step 900 is illustrated in FIG. 9, step 1000 in FIG. 10, and so on with corresponding textual explanation found in subsequent sub-sections.
The initialization and starting process is entered in step 800 . First, in step 802 , the number of CPU's present in the computer system is determined along with the context of the computer system. Part of the context determination process includes determining which operating system has overall command of the computer system. For example, a typical context for the present invention would have a PENTIUM PRO multiprocessor (made by Intel Corp.) utilizing A WINDOWS NT (manufactured by Microsoft Corp.) as an operating system. Once the context has been determined, the V-IOP driver will be initialized in step 804 . The manner in which the V-IOP driver is initialized depends upon the context detected in step 802 . Next, in step 900 , the V-IOP driver will be initialized. Once the V-IOP driver has been initialized, the first V-IOP CPU is launched in step 1000 . A check is made in step 806 to determine whether any more V-IOPs were requested (per the installation procedure). If so, step 1000 is repeated until all of the requested V-IOP CPUs have been launched. Once all of the V-IOP CPUs have been launched, the V-IOP driver is started, step 1100 . The initialization status is then returned to the host OS in step 808 and the initialization and startup process ends in step 810 and control is returned to the calling module.
Initialization of the V-IOP Driver
FIG. 9 illustrates the initialization process for the V-IOP driver. As mentioned earlier, one of the features of the present invention that is not duplicated in the prior art is the utilization of shared memory for IOP purposes instead of requiring extra RAM on a separate IOP card. One consequence of this feature is the need to allocate a region of shared memory ( 106 of FIG. 1) for use by the V-IOPs and the V-IOP driver. The process is entered in step 902 and, in step 904 , shared memory is allocated for use by all V-IOPs and the V-IOP driver. Finally, the hardware abstraction layer (HAL) is scanned for processor control registers (PCRs), step 906 . This process is ended in step 908 and control is returned to the calling module for subsequent processing (e.g., step 1000 of FIG. 8 ).
Launching of the V-IOP
FIG. 10 is a flow diagram showing the launching of the V-IOP (step 1000 of FIG. 8 ). Portions of this process are illustrated more fully in FIGS. 12 and 13, as well as textually later in this description.
After the process is entered (step 1002 ), the target CPU is initialized, step 1200 . A “target” CPU is one that has been designated for IOP processing. As mentioned earlier, the specific CPU that is targeted is not determined until startup time, to accommodate possible problems in the computer system that may not have been present when the V-IOP software was installed onto the computer system. Once the target CPU has been initialized, the target CPU is started in step 1300 to form a V-IOP. This initialization/startup procedure is performed for each of the CPUs that has been designated as an IOP. The process terminates and control is returned for subsequent processing, e.g. step 806 of FIG. 8 .
Startup of the V-IOP Driver
FIG. 11 is a flow diagram showing the details of the startup process of the V-IOP driver (step 1100 of FIG. 8 ). The process is entered in step 1102 . First, in step 1104 , the entry points in the Interrupt Dispatch Table (IDT) are saved. Next, in step 1106 , the saved entry points are patched into the dispatch routine's code space. In step 1108 , the Inter-Processor Interrupt (IPI) and End of Interrupt (EOI) codes for the specific platform are verified. Once verified, the IPI and EOI codes are used to connect the various interrupt event handlers in step 1110 . In step 1112 , the virtual adapter memory region of the shared memory (i.e., the system memory 106 of FIG. 7) is mapped and the first page of this memory region is marked “Not-Present.” By marking this memory region Not-Present, calls using this memory space, such as I/O-related calls to/from I/O devices will cause a page fault. Once the page fault occurs, it is intercepted by the V-IOP driver, the command interpreted, and, if necessary redirects the command to one of the V-IOPs. Note, only the first page is marked “Not-Present.” In step 1112 , caching is enabled for the remaining pages of the virtual adapter memory region.
Next, in step 1114 , it is determined which PCI bus and PCI slot will be used to report back to the OSM. Subsequently, in step 1116 , for each supported adapter, the PCI space in shared memory is scanned for information. This PCI information is placed into each adapter's PCI configuration information. In step 1118 , hooks are made on the kernel and the HAL routines needed to intercept the I/O-related calls. Finally, the V-IOP driver is “kicked-off” with a “NOP” (no operation) messaged which, in this context, is essentially a “Go” message. The V-IOP driver startup routine ends in step 1122 and control is returned (to step 808 of FIG. 8) for subsequent processing.
Initialization of the Target CPU
FIG. 12 is a flow diagram showing the Target CPU Initialization. The process is entered in step 1202 . First, in step 1204 , shared system memory is allocated for the iRTOS Executive Function Array and the array itself is then built. In step 206 , a check is made to determine whether one of the V-IOP CPU's has already been initialized. If so, execution skips to step 1218 . If not, then the next four steps are executed. In step 1208 , V-IOP information is extracted from the shared memory. Next, in step 1210 , The heap is extracted from the shared memory and initialized. Subsequently, with all of the critical information in place, the V-IOP PCI configuration space information is filled in during step 1214 . Once this information is filled in, the specific physical address of the shared memory is passed back to the PCI configuration space in step 1216 .
Step 1218 is executed only after at least one V-IOP CPU has been installed. During step 1218 , memory is allocated for the virtual inbound and outbound FIFO's in the local heap. In the preferred embodiment of the present invention, the inbound and outbound FIFOs are both concurrent and non-blocking. However, other FIFO schemes, such as preemption-safe locking, can be utilized. Once the memory is allocated, then the virtual inbound and outbound FIFO's are initialized, step 1220 . With the FIFO's initialized, the inbound FIFO is filled with the available MFA's (Message Frames) for use by the OSM in step 1222 . Next, in step 1500 , the list of active event queues is created. Step 1500 is described in more detail below and in FIG. 15 . Finally, in step 1600 , the resources that are required to implement the iRTOS in the V-IOP are allocated. Step 1600 is described in more detail below and in FIG. 16 .
Startup of the Target CPU
FIG. 13 is a flow diagram showing the V-IOP (Target CPU) Startup. The process is entered in step 1302 . First, in step 1304 , a check is made to determine whether a V-IOP has been initialized. If so, then execution is redirected to step 1400 . Otherwise, execution continues on to step 1306 . In step 1306 , a check is made to determine if a “Go” message was received from the V-IOP driver (indicating that the V-IOP has been initialized). If no “Go” message has been received, then step 1306 is re-executed—essentially placing the process in a wait mode until a “Go” signal is received from the V-IOP driver.
Once the “Go” signal has been received, execution resumes at step 1308 , where the virtual adapter table for each available adapter is initialized. Next, in step 1310 , memory for a local message frame is allocated and the Device Attach message is constructed. Subsequently, a message is posted to the Executive (i.e., the inbound FIFO). Afterwards, a signal is dispatched to indicate that the initialization of the V-IOP is complete. Once the V-IOP has been initialized, is now ready to handle interrupt requests per step 1400 . Step 1400 is described in more detail below and in FIG. 14 .
Handling Interrupt Requests
FIG. 14 is a flow diagram showing the method of handling interrupt requests. The process is entered in step 1402 where a check is made to determine if the signal was an IRQ (interrupt request). If so, an assert process is executed in step 1404 . The assert process of step 1404 is required because the iRTOS in the V-IOP OS runs as a software emulation that is not directly connected to a specific hardware device (that would otherwise issue the IRQ). In the assert process, the V-IOP OS posts a message to the outbound post list FIFO that asserts the IRQ to the proper hardware device.
If the signal is not an IRQ, or if the assert process has been performed, then step 1406 executed where the free event object is grabbed. Next, in step 1408 , a check is made to determine whether the grabbed object is a free event object. If not, execution is routed to step 1418 . Otherwise, execution proceeds to step 1410 where the inbound posted MFA is removed. A check is made immediately to determine if an MFA was removed in step 1412 . If not, then the free event is placed onto the free event list in step 1414 and execution is then routed to step 1418 . If, however, an MFA was removed in step 1412 , then the event object is posted to the target event queue in step 1416 . In step 1418 , the next active event queue is grabbed. A check is made in step 1420 to determine if the grabbing step of 1418 was successful. If not, execution is rerouted all the way back to the beginning to step 1402 . Otherwise, if successful, then execution is allowed to proceed to step 1422 .
In step 1422 , the highest priority event is grabbed. The success or failure of step 1422 is determined in step 1424 . If failure was detected in step 1422 , then the event queue is placed onto the active event queue and execution is rerouted to the beginning at step 1402 to await the next signal. Otherwise (i.e., success was detected in step 1422 ), then execution proceeds to step 1428 where the event is dispatched. Once the event is dispatched, the free event object is placed onto the free event list, step 1430 . Finally, in step 1432 , the event queue is placed onto the active event queue list and the process ends in step 1434 .
Creating the Active Event Queues
FIG. 15 is a flow diagram showing the creation of the List of Active Event Queues. This process starts in step 1502 . First, in step 1504 , the active event queue list is created. Next, in step 1506 , memory in the shared memory heap is allocated. Once allocated, the active event queue is initialized in step 1508 . Next, in step 1510 , the free event list is created and, in step 1512 , the free events list is filled with the available event objects. Execution is returned to the calling routine in step 1514 (see FIG. 12 ).
Allocating the Resources for the V-IOP iRTOS
FIG. 16 is a flow diagram showing the allocation of resource required to implement the iRTOS in the V-IOP. This process is started in step 1602 . First, the event queue for the Executive is created in step 1604 . Next, the Executive dispatch table is created in step 1606 . Finally, the Executive device object is created and initialized in step 1608 . Execution is returned to the calling routine in step 1610 (see FIG. 12 ).
The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While the present invention has been depicted, described, and is defined by reference to particular preferred embodiments of the invention, such references do not imply a limitation on the invention, and no such limitation is to be inferred. The invention is capable of considerable modification, alternation, and equivalents in form and function, as will occur to those ordinarily skilled in the pertinent arts. The depicted and described preferred embodiments of the invention are exemplary only, and are not exhaustive of the scope of the invention. Consequently, the invention is intended to be limited only by the spirit and scope of the appended claims, giving full cognizance to equivalents in all respects.
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A software program is used in conjunction with a standard general purpose multi-processor computer system as a means of implementing an I 2 O-compliant input-output processor (“IOP”) without requiring a special hardware IOP processor embedded on a PCI device card and connected to a computer system PCI bus. At least one of the multi-processor is targeted for operating a special software operating system module. The special software operating system module is capable of emulating the I 2 O-compliant input-output operating system program. This enables the targeted CPU to act as a virtual IOP. A driver software module is inserted into the operating system during computer system initialization which causes the software operating system to operate as if it is communicating with a physical IOP installed on a PCI bus, but instead the driver software module is redirecting the message to one of the virtual IOPs, thus making operation of the computer system indistinguishable from messages that would have been processed by a hardware implemented IOP in a computer system. Legacy computers may also implement I 2 O functionality without needing to be PCI bus configured, nor requiring special hardware IOP.
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This is a continuation of application Ser. No. 08/256,959, filed as PCT/GB93/00204, Jan. 29, 1993, which is now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to chiral synthesis; more particularly, it relates to the modification of enzymes to facilitate such synthesis.
Enzymes are biological catalysts which are specific both in terms of chemical activity and substrate structure, and it is this specificity which has been exploited in a variety of commercial applications. Although many such activities are known, it may be desirable to change the range of substrates that are suitable for catalysis and/or to change the efficiency of a given catalysis for a particular type of enzyme. Given a type of enzyme with known key elements vis-a-vis substrate preference and hence activity, it may be possible purposefully to change those elements to bring about desired modifications and hence to expand the potential industrial utility of a particular enzyme.
Enzyme activity is primarily controlled by the amino acid composition especially in certain important functional areas of the enzyme, altering these amino acids is known to change activity and may be achieved by the use of either specific or non-specific techniques. For example, the introduction of a neutralising amino acid may facilitate the catalysis of a substrate with an altered charge and this could be regarded as a predictable alteration, although no result may ever be predicted with total certainty, especially where the tertiary structures of enzymes are not as precisely known as would be necessary for complete confidence. However, while it is possible to make individual changes by known means, this would prove an almost infinite task and so it is often convenient initially to make a "macro-change" and then to "fine tune" with discrete changes. Of course, in a given case, a macro-change may prove to be sufficient, or, indeed, discrete changes may be all that are required.
Although alteration of the enzyme structure has been described, this is not achieved by any direct effect on the amino acid components, but by known techniques on the DNA encoding for the enzyme prior to protein transcription. Taking as an example the enzyme lactate dehydrogenase (natural substrate pyruvate), when acting on the carboxylic acid analogue of pyruvate, oxalo acetic acid, it would have substantially reduced activity due to the negative charge introduced into the active site. In this case, site-directed mutagenesis involving the introduction of a neutralizing charge into the correct region of the active site alters substrate specificity allowing the enzyme to take on the activity that would be expected of a malate dehydrogenase. Such specific mutations may be considered predictable in gross terms, but are very unlikely to be the ultimate refinement in increasing specificity towards such a substrate. For alternative substrates, such as those with increased alkyl chain lengths, phenyl residues or heterocyclic additions, predictions of site-specific changes are unlikely to be reliable. It is probable that the changes necessary to accommodate such "unnatural substrates" are most likely to be required adjacent to or in the active site region of the enzyme, which in many enzymes may involve up to 20 amino acids, which may be derived from many disparate parts of the primary sequence. Clearly, if one tried to proceed by alterations in individual amino acids, the scale of the undertaking would be impractical even with modern techniques.
In order to achieve the desired objective while circumventing the above disadvantages, it is possible in the case of lactate dehydrogenase, for example, to make use of the known loop region forming part of the active site. As a convenient first step, at least a portion of the loop region may be exchanged for a larger or smaller section of loop region from a similar enzyme. This may be expected to allow some variation in substrate specificity and relative catalytic efficiency, while retaining the typical activity. Having chosen the most promising loop region for a desired substrate, which could indeed be the starting wild-type loop, specific amino acid residues may be targeted for further change. In order to secure the best possible option, it is necessary to survey all possible amino acid combinations in the positions of interest. This is done by generating random nucleotides in the region coding for the amino acids targeted. Following routine cloning, it becomes necessary to select for a desired modification from amongst the numerous alternatives produced. Such screens are in common use. This approach to enzyme engineering is facilitated by the introduction of unique endonuclease restriction sites into the coding DNA, if such are not already present, at desired points. Such changes may often be achieved by alteration in the bases without altering the amino acid encoded due to code degeneracy or alternatively they are achieved by the introduction of codes as far as possible for similar amino acids. This allows the region of particular interest to be handled independently of the remainder.
SUMMARY OF THE INVENTION
As will be appreciated from the foregoing, the present invention relates to a method for modifying the specificity and/or efficiency of an enzyme, while retaining its catalytic activity, characterised in that it comprises: selecting an enzyme, the tertiary structure of which is substantially known or deduced; identifying at least one specificity and/or efficiency-related region; identifying or constructing unique restriction sites bounding the identified region in the DNA coding therefor; generating a DNA sequence which corresponds to at least a portion of the identified region, except that the nucleotides of at least one codon are randomized, or selecting as a substitute for at least a portion of the identified region an alternative such region, which may itself be similarly randomized; using the generated or substitute DNA sequence to replace the original such sequence; expressing the DNA including the generated or substitute DNA sequence; and selecting for a desired modification so that the DNA coding therefor may be isolated.
It will be described in more detail below, but the present method may be illustrated by reference to a dehydrogenase, in particular an α-hydroxy acid dehydrogenase, such as lactate dehydrogenase. In this illustration, it is the loop region of the enzyme which is identified initially as being specificity and/or efficiency-related. Generally, the randomized DNA is generated by means of an inosine triphosphate PCR method or a spiked oligonucleotide method or a PCR assembly method, all of which will be discussed in more detail below. If a substitute is to be selected for at least a portion of the region of interest, it is often based on a corresponding sequence from a similar enzyme. Once the original DNA sequence has been replaced by the generated or substitute DNA sequence, it is cloned into a plasmid or phage vector and transformed into a bacterium or virus for expression. Thereafter, a screen may be used to select for a desired modification. Taking L-lactate dehydrogenase as an example, positions 101 and 102 are particularly appropriate for randomization.
The present invention also relates to the use of such modified enzymes particularly in the production of chiral products. Often, such processes involve the use of a cofactor recycling system. One example is the reduction of 2-oxo-4-phenyl-propanoic acid characterised in that it comprises the use of L-lactate dehydrogenase which has been modified in the loop region by the present method and another is the reduction of 4-methyl-2-oxo-3-pentenoic acid characterised in that it comprises the use of MVS/GG obtainable by the present method.
Having outlined the present invention, it will now be described more fully.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram depicting the active site of the lactate dehydrogenase enzyme.
FIG. 2 is a diagram showing how two overlapping primary products can be assembled by PCR to generate an LDH hybrid gene.
DETAILED DESCRIPTION OF THE INVENTION
The use of enzymes in chemical synthesis has gained increasing acceptance as an academic possibility, while its introduction into industrial chemical procedures is rare. The potential advantages of enzymes as catalysts, such as obtaining stereospecificity and regiospecificity under mild conditions, have initiated many attempts to obtain enzymes suitable for particular chemical conversions.
Several approaches to selection of the enzyme are possible. Experimentation with currently-available enzymes may yield surprising results in terms of breadth of substrate specificity not predictable from the literature. It is thus possible to utilise commercially-available enzymes, which may have a low catalytic efficiency, but, because of cost, may form the basis of an industrial process. A second approach is to screen large numbers of environmental micro-organisms in an attempt to effect a particular transformation. Should such an activity be obtained, it is often required that the enzyme be obtained in a purer form than whole microbial cells or crude preparations thereof. To obtain enzymes from such a screen in sufficient quantity and at a reasonable cost for an industrial process requires extensive development often with the involvement of cloning and over-expression of the gene. Another approach for obtaining suitable enzyme catalysts is to modify the structure of an existing enzyme to improve its catalysis for a particular substrate. This approach of so-called "enzyme engineering", which is in its very early stages has great potential for the preparation of catalysts for the synthesis of homochiral molecules. The importance of these molecules in the synthesis of single isomer pharmaceuticals and agrochemicals is well recognised.
Despite the obvious attraction of enzyme engineering, the results of amino acid changes are often, at best, only of limited predictability due to the structural complexity of enzymes. At present, it is not possible to predict the effect of certain amino acid changes on the finer points of substrate recognition and catalytic performance where the substrate is altered in size and additional functionalities introduced from the natural substrate. It is generally easy to predict the removal of activity by the elimination of one of the catalytically-vital amino acids which are generally well known from the classical studies of enzyme mechanism and function. To enhance the activity towards an unnatural substrate remains a challenge.
The opportunity for enzyme engineering may be calculated for a 300 residue protein of 20 amino acids as 10 390 possible sequences. The vast majority of these sequences cannot have been explored for biological function. It may be suggested that a typical large protein of 300 amino acids residues cannot represent a global optimum for any biological function, but at best is an assembly of empirically optimised 25-35 amino acid domains. Thus, enzyme engineering should be capable of improving a large frame-work for any particular target function.
Recently, methods have been developed to express random sequences of DNA as protein fused to phage M13 coat protein and it has been suggested that it will be possible to mimic the process of evolution by suitable affinity chromatography to isolate both the required protein sequences and its gene (Kang, PNAS, 88, 1991, 4363). However, just as evolution has been unable to sample all possible sequences, so too the protein engineer will be limited to the number of M13 phage that may be screened (10 15 plaque-forming units are produced per litre culture of E. coli cells containing the phage M13). With 10 15 variants, the length of DNA which may be optimised is obtained from 4 N =10 15 , i.e. N=24 bases or 8 amino acids. The other problem encountered is that a phage display system determines binding not catalysis and thus is not designed to obtain enzymes with new chemical potential.
Random mutagenesis of existing proteins is also limited in its ability to produce radically altered proteins by problems of sampling all the possible variants. In addition, the genetic code is very resistant to change. Not only are codons redundant at the third position, but also amino acid residues with similar properties are coded by similar sequences and thus resistant to sparse mutagenesis. For example: (i) a codon having a T at the second position always codes for an amino acid residue having a hydrophobic side chain; (ii) the codons for aspartate and glutamate differ only at the third position. Therefore, strategies, such as use of thioate nucleotides (Holm, Prot Eng, 3, 1990, 181) , which create randomly dispersed mutations (in which only one mutation is likely to be present in any codon) are unlikely to yield new proteins having dramatically different properties to those of the parent proteins.
Although it should be possible to engineer any designed property into any protein framework, only those which have been well characterised are likely to be redesigned successfully.
In order to obtain the fundamental knowledge required for rational redesign, a combination of crystallography, site-directed mutagenesis and transient kinetic techniques was used to relate function to structure in the NAD-dependent lactate dehydrogenases from both prokaryotes and eukaryotes. That knowledge not only revealed those amino acids required for the catalytic pathway, but also mapped those amino acids which are part of a major rearrangement of shape which is induced when the negatively-charged substrate acid enters the active site and causes the protein to sequester the substrate in an internal vacuole which is sensitive to the size of the substrate and which contains exactly balanced charge. Using this knowledge, it has been possible to design specific new enzymatic properties with respect to charged substrates and so avoid the low statistical probabilities associated with random mutagenesis. It should, of course, be appreciated that the present invention is more generally applicable than to this particular illustration.
Accordingly FIG. 1 depicts the active site of lactate dehydrogenase. In this illustration, some of the residues which determine substrate specificity are carried on the under-surface of the "upper jaw". The rate-limiting step in lactate dehydrogenase catalysis is the rate at which this loop may sweep through a viscous solvent to close onto the upper surface of helix α2G. The rate-limiting step is largely independent of the sequence of amino acids on the "upper jaw" and since the chemical step is much faster than the shape change, the lactate dehydrogenase system has the advantage that the loop sequence may be easily varied to achieve different substrate specificities without much danger that the chemical step will become rate-limiting. Thus, in order to obtain enzymes improved by engineering towards particular substrates, a combination of techniques may be preferentially employed. Specific residues may be changed to accommodate functional groups, such as an altered charge to that of the natural substrate, but to perfect the enzyme for activity towards a different substrate, elements of the infinite variability of random amino acid changes may be required. This may be applied to a particular area of the enzyme and selected for using screening techniques.
An object of the present invention was to modify an already useful, but substrate-restricted enzyme, S lactate dehydrogenase, to provide an improved catalyst for reduction of the a-keto group in acids larger than the natural substrate, pyruvate. In particular, the substrates of interest contain bulky aromatic groups.
The natural enzyme used as the basis for engineering was the thermophilic lactate dehydrogenase (LDH) isolated from Bacillus stearothermophilus, which has been cloned and expressed in Escherichia coli.
This enzyme has been one of the most thoroughly characterised protein frameworks (Dunn, C. R., et al, Philos. Trans. R. Soc. London Ser. B, 1991, 332, 184) , including the study of inhibition, substrate interaction and genetic manipulation. The physical stability of the enzyme, especially to thermal denaturation, makes it an ideal candidate for demonstrating the features of redesign which would be generally applicable to α-hydroxy acid dehydrogenases, for example.
The modification of wild-type enzymes presents a significant challenge because, even in the case of a protein with considerable literature knowledge, the results may be unexpected and surprising. Thus, redesign of even well-studied enzymes is of limited predictability.
Changes in the amino acid composition of enzymes and thus effects on kinetics and substrate specificity have occurred throughout nature and various methods have been developed in order to potentiate the natural divergence of enzyme structure. Random mutations may be produced in genetic information (and thus in the protein coded for) by the use of classical mutagenesis. Lately, the technique of site directed mutagenesis has allowed the alteration of specific bases in genes, thus producing directed amino acid changes in the target protein at a known position. Using similar techniques, it has been possible to achieve the replacement of significant amino acid sequences in a functionally important area of the enzyme.
Detailed knowledge of the protein, such as primary sequence and tertiary structure from X-ray analysis, along with molecular modelling allow the identification of the position of various amino acids in what are known as conserved regions. This is illustrated with the nomenclature of the amino acids of various lactate dehydrogenase enzymes. Thus, any structure in the protein which is retained between species is regarded as conserved and probably essential for the enzyme's function. This information will allow any change in a particular enzyme to be pinpointed for all other homologous enzymes across all general substrate types; if this were not possible the enzymes would not fulfil the same biochemical function. The enzymes of particular interest at present are α-hydroxy acid dehydrogenases, which catalyse the NADH/NADPH dependent reduction of a keto group in an α-position to a carboxylic acid, or, alternatively, the reverse reaction where the α-hydroxy group is oxidised to the ketone.
Attempts to modify the enzyme lactate dehydrogenase to expand the natural substrate specificity to allow an increased reaction rate with larger substrates with various functional groups has led to the present unpredictable observations. Although it may be possible to prepare substrates and corresponding chiral products of interest by chemical synthesis, followed by wild-type enzyme reduction, such an approach may not be attractive and it may be that preparation via a redesigned protein framework may provide a more rational and cost effective approach. Additionally, the alteration of the enzyme has demonstrated that the activity towards the natural substrate may be so dramatically reduced that completely different substrate selectivity is produced. This may not be a requirement of a biotransformation catalyst, where the enzyme is presented with only one substrate species for reduction, but, when a mixture of potential substrates is present, such as may occur in a biological sample, this may be essential for achievement of selective conversion or the determination of one particular chemical species. This alteration in substrate specificity could also be advantageous in a biotransformation using whole cells where the intended substrate is necessarily contaminated with other entities which could also be transformed.
In the work of Wilks et al (Biochemistry, 1990, 27, 8587) a mutation strategy is described for the production of NAD-dependent dehydrogenases which have altered substrate specificity. The disclosed enzymes catalyse the reduction of homologues of pyruvic acid corresponding to the general formula: C n H 2n+1 CO COOH, which may include straight- and branched-chain alkyl residues. The initial intention of the present work was to continue the design method for substrates with an aromatic function, in addition to extended alkyl residues and hydroxyl and keto substitution associated with the same base structure of α-oxoacids.
Enzymes capable of reducing such substrates would be of particular value in the field of synthetic chemistry where an α-keto compound could be converted stereospecifically to the corresponding secondary alcohol. The production of individual optical isomers of secondary alcohols is especially valuable in the manufacture of optical isomers of pharmaceuticals and drug intermediaries. The feature of thermophilicity which may be obtained with some α-hydroxy acid dehydrogenases is valuable as it enables the enzymic reactions to be carried out at relatively high temperature where a rate acceleration may exist and the enzymes are inherently stable. These enzymes may also be suitable for incorporation into determinations of the levels of particular substrates obtained in biological samples under certain disease states.
A numbering convention has evolved in the field of NAD-dependent dehydrogenases, which was originally based on an X-ray structure of dogfish muscle lactate dehydrogenase. This system numbers amino acids in ascending order extending from the N terminus. This system identifies conserved residues, such as glycine at positions 30 and 33, tyrosine at position 85, arginine at position 109, serine at position 163 and aspartic acid at position 168.
Thus, in any given NAD dependant dehydrogenase, natural or subject to mutation, there are regions of sequence which are homologous with the amino acid sequence of the numbering convention. An important aspect of this convention is that any amino acid change in an NAD dependent dehydrogenase may be accurately described.
In Table 1 below, an alignment of amino acid sequences is shown for three NAD dependent lactate dehydrogenases: the M4 isoenzyme of pig SEQ ID NO: 1, the testis isoenzyme of man SEQ ID NO: 2 and the Bacillus stearothermophilus enzyme SEQ ID NO: 3. (The symbols "-" do not signify breaks in the continuous polypeptide chains, instead they are conventional representation of discontinuities of numbering which allow alignment with sequences of other enzymes to give maximum homology.)
TABLE 1__________________________________________________________________________ ##STR1## ##STR2## ##STR3## ##STR4## ##STR5## ##STR6## ##STR7## ##STR8## ##STR9## ##STR10## ##STR11##__________________________________________________________________________Expression cloing of human testis-specific lactate dehydrogenase cDNA.Millan, J.L., Driscoll, C.E. and Goldberg E.Sequence from cDNA - Genbank accession number Jφ2938 (1986).The DNA sequence of the thermophilic lactate dehydrogenase fromBacillus stearothermophilus.Barstow, D., Clarke, A.R., Wigley, D., Holbrook, J.J. and Atkinson, T.Gene, 46, (1986), 47-55
Within the conventional numbering system are short sequences which may be correlated with specific structural elements in the folded polypeptide and which may have specific functional properties such as the substrate recognition site or the activation site.
The substrate recognition site is carried in part by a mobile loop of polypeptide chain, conventionally numbered 98 to 110. This sequence is contiguous but traditionally omits a residue 103.
It is known for α-hydroxy acid dehydrogenases of the L type which generate S stereochemistry on reduction to the hydroxy function that a mobile surface loop exists which changes conformation after substrate binding. This loop consists of the amino acid residues 98-110 and contains an arginine at position 109 which is important for catalysis as the positive charge from the amidine group stabilises the stretched substrate carbonyl and thus decreases the energy required to obtain the transition state necessary for hydride transfer.
The loop region is also involved in substrate selection and for that reason was the particular object for the present enzyme engineering study.
The mechanism by which lactate dehydrogenase distinguishes different substrates is the ability of the substrate to fit into a proton-impermeable, fixed-sized internal vacuole which is formed when the mobile surface polypeptide loop closes down onto the protein surface. Not only is loop closure only possible over suitably small and singly negatively charged substrates, but also the loop closure triggers catalysis through the arginine 109 residue. The variation in composition and length of this mobile loop region is the immediate object. For the convenience of these experiments, a particular gene for wild-type Bacillus stearothermoiphilus lactate dehydrogenase was chosen where the amino acids alanine at positions 235 and 236 had been changed for glycines. The effects of this particular amino acid substitution have been presented by Wilks et al. for a limited range of substrates (Biochemistry, 28, 8587) and generally increased the activity towards substrates with larger alkyl groups. Although used to demonstrate the principle of loop exchange, the technique would not be constrained to this particular enzyme, rather it is applicable not only to this mutant enzyme, but also to all other structurally-related α-hydroxy acid dehydrogenases, for example.
The mutation where alanines at 235,236 are replaced by glycines has been combined with three mutations in the mobile polypeptide loop (residues 98-112), namely glycine 102 by methionine, lysine 103 by valine and proline 105 by serine (MVS/GG).
This new enzyme construction was evaluated for activity towards longer substrates, in particular an unsaturated branched substrate 4-methyl-2-oxo-3-pentenoic acid, which is reduced to the following alcohol: ##STR12##
Steady state kinetic measurements indicated that reduction of this compound by the wild-type enzyme proceeded slowly, obtaining an estimate for turnover of 0.03S -1 in contrast to that obtained with the mutant enzyme of 1.2S -1 . The Km determined under similar conditions of substrate concentration (1-20 mM) in the presence of 5 mM fructose 1,6-bisphosphate (sometimes identified hereinafter as "FBP") was 22 mM. This observation regarding the specificity alteration towards a less flexible substrate indicates that the loop region has importance in substrate reduction.
The method used to make new loop constructions was to insert restriction enzyme sites at either end of the DNA coding for the loop region. These new restriction sites which are unique within the DNA coding for the enzyme, are cleaved and then religated with synthetic DNA designed to code for the required new loop region. One of the restriction sites introduced was for SacII near amino acid 97. The construction of the Sac II restriction site required that the wild type coding sequence for cysteine 97 was changed to threonine. The Xba1 site retained the wild-type amino acid sequence with arginine at 109, but did result in the creation of an MluI site close to threonine 108. The new MluI site was used to advantage as it was destroyed in transformants and thus enabled easy distinction thereof from the wild-type gene.
To illustrate the utility of the loop design approach to enzyme engineering, novel loops were introduced, two shorter by 3 amino acids and one longer by 4 amino acids. The new enzymes generated in this manner were evaluated against a range of experimental substrates to determine the effect of the loop exchanges.
It was clearly demonstrated that the new loops altered the properties of the enzyme from that of the framework used in the construction thereof. The results also illustrate the difference obtained with the alanine→glycine alteration at amino acids 235 and 236 and the introduction of the threonine in place of cysteine at amino acid 97.
The increase in turnover of α-ketocaproate and α-ketoisocaproate with the alanine→glycine double mutation was consistent with the results of Wilks et al. (Biochemistry, 29, 1990, 8587). The increase in turnover for the aromatic substrate 2-oxo-4-phenyl propanoic acid: ##STR13## along with increases in the Km for both was not obvious and indicates useful improvement with respect to the use of the mutant enzyme in the synthesis of the chiral α-hydroxy group of this aromatic substrate.
The exchange of threonine for cysteine at amino acid 97 maintained the beneficial Km effect for 2-oxo-4-phenyl butanoic acid: ##STR14## over the wild-type enzyme.
The effect of these individual mutations on the reduction of the aromatic substrates is of clear interest as the homochiral hydroxyacids produced form useful chiral building blocks for the synthesis of bioactive compounds.
The introduction of the new loop sequences further alters the substrate specificity of the enzyme reducing the turnover of the natural substrate from that of the wild type enzyme. The three new loop enzymes retained most of the wild type catalytic potential towards the 2-oxo-4-phenyl propanoic acid as shown by turnover and Km and, in the example of the longer loop and second shorter loop version, resulted in an increase in turnover.
These examples serve to illustrate that the activity of the enzyme may be dramatically altered by changes in the loop sequences, both towards the natural substrate and larger unnatural substrates.
In the large loop, it is observed that the Kcat/Km for 2-oxo-4-phenyl propanoic acid was 1700 times better than for pyruvate compared to the wild type enzyme which is conversely 230 times better for pyruvate, representing a switch in specificity of 391,000 fold.
The alteration in specificity of the enzyme from pyruvate to 2-oxo-4-phenyl propanoic acid renders the new enzyme suitable for the determination of the concentration of 2-oxo-4-phenyl propanoic acid, often termed phenyl pyruvate in clinical chemistry nomenclature, especially from body fluids, such as blood and urine.
Phenyl pyruvate levels are normally low, but rise to significant levels with the increase in phenylalanine concentration, which is associated with the genetic disease phenylketonuria (Langenbeck et al., J. Inher. Metab. Dis., 4, 1981, 69). It is also possible that the phenyl pyruvate reductase or phenyl lactate dehydrogenase enzyme could be used in conjugation with phenylalanine dehydrogenase, a current method of determining the phenylketonuria level such that interference from phenyl pyruvate could be negated, thereby enhancing the sensitivity of the phenylalanine-based method.
The construct having the restriction sites at either end of the loop region may be used to produce a series of dehydrogenases having loops of variable length and variable sequence. Thus, by restricting random mutagenesis to the region of lactate dehydrogenase which has been identified as being important for substrate recognition, it is possible to isolate enzymes which may carry out a desired chiral reduction. The random mutagenesis may be generated by use of spiked oligonucleotides at specific positions and on different length loops or, alternatively, by the incorporation of inosine triphosphate in a polymerase chain reaction (PCR) that randomises either the entire loop region or specific residues. Both of these techniques have been employed to prepare mutant libraries using the restriction sites engineered into the DNA coding for the loop region of LDH. A further PCR method was used to generate a random combinational DNA library of specific positions of the loop region. This technique was specifically targeted to positions 101 and 102 as these are involved in defining enzyme substrate specificity.
The PCR was initially used to generate 300 & 800 base pair fragments that had complementary overlapping ends. These primary products which had random sequences incorporated in the overlap, were then primed on each other and extended to yield an LDH hybrid gene. A second PCR with two outer primers annealing at non-overlapping ends was finally used to amplify the LDH product.
Previous manipulation of the Bacillus stearothermophilus LDH gene involved cloning an EcoRI/PstI digested gene in to PKK 233-2, or M13 plasmid vectors. Where, as now, it is possible to clone the PCR product into any one of a number of vectors, because one of the outer primers (2), which anneals past the coding region, was designed with an additional EcoRI site incorporated. For example, in order to verify that there is a representative library with random sequences in the desired positions, it is possible to clone the gene with unique EcoRI sites into PUC18, which produces a high yield of DNA from mini-preps, and subsequently the PCR product may be cloned into plasmid or phage expression vectors, such as PKK 233-2. (See accompanying illustrative FIG. 2.)
The following advantages are obtained with the PCR method:
1. High yield of PCR product obtained.
2. The ability to identify product as mutant DNA and select against wild-type sequences via MluI digestion.
3. Ease of handling and monitoring a 1 kb product compared to previous attempts which involved designing restriction sites either side of the loop region, such that a 40 base pair wild-type sequence may be replaced with a mutant sequence.
4. Speed of method.
5. The design of primer 2 with an EcoRI site enables the cloning of gene product into a number of vectors.
6. Use of double-stranded template for mutagenesis.
7. Application of method to manipulate other areas of the LDH gene and the ease by which interesting mutations in different regions may be brought together in one molecule using this splice overlap extension method.
8. Having mutant oligos with a high region of complementarity to the template at the 3'-end ensures that annealing of oligos to the vector is highly efficient.
In order successfully to utilise a directed random mutagenesis method that generates a library of mutants covering the loop region of the enzyme, or indeed any specific region of any target enzyme, requires a suitable screen for clones which express mutant enzymes of the desired specificity. For the dehydrogenases, this is simply provided by coupling NADH production with phenazine metasulphate to formation of insoluble blue formazan dye.
The screen is based on the work of Katzen and Schimkel (PNAS, 54, 1218) and relies on the ability of a colony expressing an enzyme with specificity to oxidise the required substrate and to reduce NAD + to NADH. The reduced coenzyme then reduces phenazine metasulphate which in turn reduces nitroblue tetrazolium to form an insoluble blue dye.
The mutant DNA is transformed into competent E. coli cells and is stored on agar plates containing 15% glycerol and ampicillin at -80° C. obtaining electro-competent cells with high transformation rates has produced rates of 10 6 per μg of DNA, a rate which produces a sufficiently representative population of mutant colonies for screening. Copies of this plate are made using a velvet replicator and the copies grown up overnight. (The E. coli LDH activity is removed by incubation of the filter paper at 67° C. for 30 minutes, the activity of the wild-type enzyme is not lost until 45 minutes at this temperature.) The copies are then screened against a range of substrates and individual colonies may be compared. Each master plate is screened at least three times to ensure conditions are ideal in each case.
Using this technique demonstrates differential rates of staining have been shown between filter copies of wild-type colonies and those containing the malate dehydrogenase activity mutant enzyme (Q102R) with lactate and malate as substrates, respectively, confirming the validity of the screen to identify individual colonies.
The following illustrates the present invention:
Mutagenesis of lactate dehydrogenase
Mutants of lactate dehydrogenase from Bacillus stearothermophilus were generated by the oligonucleotide mismatch procedure of Winter et al. (Nature, 1982, 299, 756) in M13 with the mutagenic oligonucleotide as the primer for in vitro chain extensions. The double alanine replacement at 235 and 236 by glycine was obtained using the oligonucleotide sequence as SEQ ID NO: 4 3'CGCGCTACCGCCGATGTTTA5'. The wild type and mutant enzymes were expressed in the PKK223-3 plasmid in E. coli (Barstow et al., Gene, 1986, 46, 47).
Mutagenesis to construct Sac II and XbaI sites at either end of the gene coding for wild type active site loop
A 54-mer oligonucleotide was used to direct mutagenesis to introduce unique restriction sites (SacII and XbaI) at either end of the active site loop (amino acids 98-110) using the wild-type template (Barstow loc. cit). The mutagenic oligonucleotide SEQ ID NO. 5 was: 5'GTCCACAAGGTCTAGACGCGTCTCGCCCGGTTTTTGGTTGGCGCCCGCGGTAATGACAAC3', the annealing, chain extension and cloning were as described by Clarke et al. (Nature, 1986, 329, 699).
Mutants were identified by making mini-preps and restricting with SacII and XbaI. Mutant mini-preps were restricted with EcoRI and XhoI and the small fragment was subcloned into PKK223-3 containing Ala235Gly, Ala236Gly mutant LDH from which the small EcoRI/XhoI fragment had been removed (Wilks et al. Biochemistry, 1990, 29, 8587). The resulting plasmid (pLDHrs) was transformed into competent E. coli TG2 cells. The whole sequence was redetermined using a "Dupont Genesis 2000" automatic sequencer and showed the correct loop sequence had been inserted. The partial DNA sequences of the wild type gene and the mutant with inserted restriction sites are shown in Table 2 below.
TABLE 2__________________________________________________________________________Comparison of the protein and DNA sequences of wildtype B.stearothermophiluslactate dehydrogenase in loop (93-111) region of wildtype and the mutantwth Sac IIand Xba I restriction sites at either end of the loop, and the variableloop sequences derived from them.__________________________________________________________________________Wild-type DNA sequence in loop region (Cys changed to Thr) identified asSEQ ID No 6:LeuValValIleCysAlaGlyAlaAsnGlnLysProGlyGluThrArgLeuAsp.sup.5' TTGGTTGTCATTTGCGCCGGCGCCAACCAAAAACCGGGCGAGACGCGGCTTGAT.sup.3'.sup.3' AACCAACGATAAACGCGGCCGCGGTTGGTTTTTGGCCCGCTCTGCGCCGAACTA.sup.5'Mutant DNA (pLDHrs) sequence in loop region identified as SEQ ID No 7:LeuValVALIleThrAlaGlyAlaAsnGlyLysProGlyGluThrArgLeuAsp.sup.5'TTGGTTGCTATTACCCCCCCCGCCAACCAAAAACCGGGCGAGACGCGTCTACAC.sup.3' ##STR15##Two oligonucleotides (LLA and LLB) used to synthesise the big loop byPCTidentified as SEQ ID No: 8 and SEQ ID No 9, respectively:.sup.5'TACCGCGGGCAACATTAAATTGCAACAAGATAA.sup.3'(LLA)5'GGTCTAGACGATCGCCCGTCGGGTTATCTTGTT.sup.3'(LLB)Big loop sequence in the 97-110 region identified as SEQ ID No: 10 (notetheMlu1 site is destroyed):CysAlaGlyAlaAsnGlnLys------------ProGlyGluThrArgLeuAsp(wildtype)ThrAlaGlyAsnIleLvsLeuGlnGlnAspAsnProTnrGlyAspArgLeuAsp(bigloop).sup.5'TACCGCGGGCAACATTAAATTGCAACAAGATAACCCGACGGGCGATCGTCTAGACC .sup.3' ##STR16##Oligonucleotides for PCT synthesis of LeuLysGly and SerLysGly shortloopsidentified as SEQ ID No: 11, SEQ ID No: 12 and SEQ ID No: 13,respectively:SLA5' TACCGCGGGCGCCAACT3'SLB5' GGTCTAGACGGCCTTTGGAGTTGGCGCC3'SLC5' GGTCTAGACGGCCTTTGGAGTTGGCGCC3'Short loop sequence in the original 97-111 region, identified as SEQ IDNo. 14and SEQ ID No. 15, respectively ( Mlu1 site is again destroyed): ##STR17## ##STR18##5'TACCGCGGGCGCCAACTTGASAAGGCCGTCTAGACC3'3'ATGGCGCCCGCGGTTGAACTTTCCGGCAGATCTGG5' ##STR19##5'TACCGCGGGCGCCAACTCCAAAGGCCGTCTAGACC 3' ##STR20##__________________________________________________________________________
PCR assembly method for generation of random combinational library of the loop region of the B. stearothermophilus LDH gene:
1. Single-stranded oligos were made such that the oligos were only different to the wild-type sequence at positions encoding amino acids 101 and 102 where each one of the bases A, T, C, G has an equal chance of being inserted. (Oligo mix 101,102 forward.)
2. An MluI restriction site which is present in the wild-type template is destroyed by change of the third codon position of amino acid 108 from an ACG to an ACT without altering threonine as the amino acid being coded. The absence of the MluI site enables verification that the mutants have been generated and to select against wild-type sequences.
3. A DNA primer which has 14 base homology to olio mix 101,102 forward was used to make the complementary strand (oligo mix 101,102 reverse) using a Klenow reaction.
4. Single-stranded library oligos were used with primer 1 and 5 ng of wild-type template in order to generate a 300 base pair product with 25 cycles of PCR (94° C., for 1 minute, 55° C. for 1 minute, 72° C. for 2 minutes).
5. Double-stranded Klenow oligos were used with primer 2 and 5 ng of wild-type template to generate an 800 base pair product which overlaps the 300 base pair product. (PCR conditions as in 4.)
The use of double-stranded oligo as primer in 5 is very important in ensuring that both the 300 and 800 base pair products are made and primed using mutant oligos and that the wild-type sequence at position 101 and 102 is not copied.
6. After gel purification, 20 ng of the 300 base pair product and 60 ng of the 800 base pair product were mixed without primers and thermocycled seven times in order to join the fragments (94° C. for 2 minutes, 55° C. for 1 minute, 72° C. for 4 minutes).
7. After seven cycles, primers 1 and 2 were added, and the product amplified for twenty cycles (94° C. for 1.5 minutes, 55° C. for 1 minute, 72° C. for 2.5 minutes).
8. The 1 kb PCR product was then gel purified, digested with EcoRI, and gel purified again before ligation into EcoRI-cut PUC18 plasmid vector and transformation into E. coli.
9. Recombinant colonies were selected for by IPTG and X-Gal insertional inactivation.
10. Of the nine white colonies picked, seven were verified for the presence of the LDH gene and to resistance to MluI digestion via gel and restriction analysis. The other two did not have inserts.
11. Six of the mutants were sequenced using a Dupont 2000 sequencer and confirm that the random mutagenesis approach had been achieved.
See Table 3 below:
TABLE 3__________________________________________________________________________ ##STR21## ##STR22##__________________________________________________________________________
Generation of double-stranded DNA loop fragments by oligonucleotide-overlap
Each pair of overlapping oligonucleotides (20 μM of each) were subjected to 30 cycles of annealing and extension (94° C. for 1 minute, cool to 45° C. for 2 minutes, 45° C. for 1 minute, heat to 72° C. in 1 minute, 72° C. for 1 minute in 50 μl containing 0.05M KCl , 10 mM Tris pH 8.3, 1.5 mM MgCl 2 , 0.01% gelatin), 200 μM of each dNTP and 2.5 units TAQ DNA polymerase). The double-stranded DNA product was purified and then cut with SacII and XbaI before ligating it into the plasmid pLDHrs cut with the same enzymes. The ligated products were restricted with MluI to cleave wild-type plasmid pLDHrs.
The DNA was purified, microdialysed and used to transform E. coli TG2 cells by electroporation. Transformed cells were selected for ampicillin resistance. Ten such colonies were picked and plasmid DNA purified from overnight cultures. The presence of mutant loops was confirmed by resistance to MluI digestion.
The expression of the enzymes was obtained as described above.
Purification of lactate dehydrogenase and mutants
Overnight cultures (11) were centrifuged and the packed cells were resuspended in 50 mM triethanolamine, pH 6.0. The cells were sonicated and the debris was removed by centrifugation. The protein in the supernatant was precipitated by the addition of 65% ammonium sulphate. The precipitate was spun down and resuspended in 50 mM triethanolamine, pH 6.0 and dialysed against the same buffer. After dialysis, NADH and FBP were added to the protein to final concentrations of 5 mM and 10 mM before loading onto an oxamate Sepharose column which had been pre-equilibrated with 50 mM triethanoloamine, pH 6.0, 3 mM NADH and 5 mM FBP. After washing off unbound protein with column buffer mutant LDH was eluted with 50 mM triethanolamine, pH 9.0, 0.3 M NaCl. The elutant was precipitated with 65% ammonium sulphate and then resuspended in and dialysed against 50 mM triethanolamine, pH 7.5. The protein was then loaded onto a Q-Sepharose Fast Flow column and eluted with a salt gradient. LDH eluted at a concentration of 0.25M NaCl. For the double glycine mutant enzyme, the first chromatography procedure with oxamate Sepharose was replaced by chromatography on Blue Sepharose -F3GA, otherwise the procedure was essentially the same. All proteins were judged to be greater than 98% pure from the intensity of Coomassie blue staining on an SDS Phast gel (Pharmacia). The yield of protein was usually 0.2 g/l of original broth.
Steady-State Kinetics
Steady-state measurements were made by following the reduction in absorbance at 340 nm in the NADH/NAD + conversion. All assays were at 25° C. in the buffer Bis-Tris, pH 6, (20 mM), containing KC1 (50 mM) and when used fructose-1,6-bisphosphate at 5 mM. Protein concentration was determined from the absorbance at 280 nm using the value of 0.91 for 1 mg/ml protein in 1 cm path and an Mr of 33,000.
The results from these determinations are shown in Table 4 below. The specific substrates used in the evaluations are shown in the left column of Table 4. In Table 4, "235/6GG" denotes the mutant enzyme formed by substituting GlyGly for AlaAla at the 235-236 positions of the enzyme (Wilks et al., Biochemistry 1990, 29, 8587-8591), and "WTrs" denotes a mutant derived from the wild-type strain as shown in FIG. 1 of Wilks et al., Biochemistry 1992, 31, 7802-7806.
TABLE 4__________________________________________________________________________Steady State Kinetic Parameters of some Loop Exchange Mutants WILD- BIG TYPE 235/6.sub.GG WTrs LOOP SL1 SL2 ENZYME +FBP -FBP +FBP -FBP +FBP -FBP +FBP -FBP +FBP -FBP +FBP -FBP__________________________________________________________________________PYRUVATE k.sub.cat s.sup.-1 250 250 167 -- 60 19 0.2 0.05 0.2 0.1 0.07 0.04 K.sub.m mM 0.06 2 4 -- 3.5 100 42 50 0.08 2.0 0.065 0.5k.sub.cat /K.sub.M M.sup.-1 · s.sup.-1 4.2E6 5E4 4.2E4 -- 1.7E4 -- 4.7 -- 2.5E3 -- 1076 80KETO k.sub.cat s.sup.-1 29 -- 240 -- 88 12 6 0.3 0.8 0.07 0.1 0.1CAPROATE K.sub.m mM 3.4 -- 5.6 -- 5.8 30 20 27 16 20 25 60k.sub.cat /K.sub.M M.sup.-1 · s.sup.-1 8.5E3 -- 4.2E4 -- 1.5E4 -- 300 -- 50 -- 4 1.6KETOISO k.sub.cat s.sup.-1 0.33 -- 1.74 -- 1.8 0.2 0.3 0.06 0.07 0.01 0.9 0.08CAPROATE K.sub.m mM 6.7 -- 15.4 -- 4 28 18 32 20 40 25 30k.sub.cat /K.sub.M M.sup.-1 · s.sup.-1 50 -- 112 -- 450 -- 17 -- 3.5 -- 36 2.62-OXO-4-PHENYL K.sub.cat S.sup.-1 6 -- 7 -- 6 0.8 1.0 0.1 0.03 0.002 0.2 0.01BUTANOATE K.sub.m mM 0.6 -- 13 -- 4 12 7 12 4 4 4 4k.sub.cat /K.sub.M M.sup.-1 · s.sup.-1 1E4 -- 538 -- 1.5E3 -- 143 -- 7.5 -- 50 2.52-OXO-4-PHENYL k.sub.cat s.sup.-1 32.7 -- 53.4 -- 58 4 40 6 20 10 100 20PROPANOATE K.sub.m mM 1.8 -- 4.5 -- 6 21 5 100 11 80 3 20k.sub.cat /K.sub.M M.sup.-1 · s.sup.-1 1.8E4 -- 1.2E4 -- 9.6E3 -- 8E3 -- 1.8E3 -- 3.3E4 1E3__________________________________________________________________________ K.sub.m values above 50 mM are less accurate due to the large substrate absorbance
Reduction of 4-methyl-2-oxo-3-pentenoic acid using MVS/GG (the mutant enzyme formed by substituting MetValSer for GlnLysPro at the 102-105 positions and GlyGly for AlaAla at the 235-236 positions):
MVS/GG (6 units (μ moles/minute/30° C.)) and yeast formate dehydrogenase (5 units) were added to a solution of 4-methyl-2-oxo-3-pentenoic acid (1.0 mM) in deoxygenated Tris buffer (5 mM:pH 6.0; 80 ml) containing NADH (0.02 mM), sodium formate (3.1 mM), fructose-1,6-bisphosphate (0.4 mM) and dithiothreitol (0.08 mM). The solution was stirred at room temperature (-20° C.) under nitrogen for 5 days with periodic addition of 0.2 mM HCl to maintain pH in the range of 6.0-6.2. Acidification to pH 2.0 and extractive work-up with ethyl acetate gave (S)-2-hydroxy-4-methyl-3-pentenoic acid in 91% isolated yield. Analysis of the (R)-MTPA derivative and comparison to a racemic standard gave a value of at least 99% for entantiomeric excess.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 15(2) INFORMATION FOR SEQ ID NO: 1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 333 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(iii) HYPOTHETICAL: NO(iii) ANTI-SENSE: NO(v) FRAGMENT TYPE: internal(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (29 30)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (42 43)- numbering discontinuity"te= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (43 44)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (44 45)--- numberingORMATION: /note= "discontinuity"(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (54 55)- numbering discontinuity"te= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (83 84)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (87 88)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (97 98)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (129 130)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (152 153)--- numberingORMATION: /note= "discontinuity"(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (190 191)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (195 196)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (210 211)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (245 246)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (249 250)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (266 267)- numbering discontinuity"te= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (279 280)--- numberingORMATION: /note= "discontinuity"(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (302 303)numbering discontinuity"note= "(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 1:AlaThrLeuLysGluLysLeuIleAlaProValAlaGlnGlnGluThr151015ThrIleProAsnAsnLysIleThrValValGlyValGlyGlnValGly202530MetAlaCysAlaIleSerIleLeuGlyLysSerLeuThrAspGluLeu354045AlaLeuValAspValLeuGluAspLysLeuLysGlyGluMetMetAsp505560LeuGlnHisGlySerLeuPheLeuGlnThrProLysIleValAlaAsn65707580LysAspTyrSerValThrAlaAsnSerLysIleValValValThrAla859095GlyValArgGlnGlnGluGlyGluSerArgLeuAsnLeuValGlnArg100105110AsnValAsnValPheLysPheIleIleProGlnIleValLysTyrSer115120125ProAsnCysIleIleIleValValSerAsnProValAspIleLeuThr130135140TyrValThrTrpLysLeuSerGlyLeuProLysHisArgValIleGly145150155160SerGlyCysAsnLeuAspSerAlaArgPheArgTyrLeuMetAlaGlu165170175LysLeuGlyValHisProSerSerCysHisGlyTrpIleLeuGlyGlu180185190HisGlyAspSerSerValAlaValTrpSerGlyValAsnValAlaGly195200205ValSerLeuGlnGlnLeuAsnProGluMetGlyThrAspAsnAspSer210215220GluAsnTrpLysGluValHisLysMetValValGluSerAlaTyrGlu225230235240ValIleLysLeuLysGlyTyrThrAsnTrpAlaIleGlyLeuSerVal245250255AlaAspLeuIleGluSerMetLeuLysAsnLeuSerArgIleHisPro260265270ValSerThrMetValGlnGlyMetTyrGlyIleGluAsnGluValPhe275280285LeuSerLeuProCysValLeuAsnAlaArgGlyLeuThrSerValIle290295300AsnGlnLysLeuLysAspAspGluValAlaGlnLeuLysAsnSerAla305310315320AspThrLeuTrpGlyIleGlnLysAspLeuLysAspLeu325330(2) INFORMATION FOR SEQ ID NO: 2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 327 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(iii) HYPOTHETICAL: NO(iii) ANTI-SENSE: NO(v) FRAGMENT TYPE: internal(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (16 17)- numbering discontinuity"te= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (27 28)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (40 41)- numbering discontinuity"te= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (41 42)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (42 43)--- numberingORMATION: /note= "discontinuity"(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (52 53)- numbering discontinuity"te= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (81 82)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (85 86)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (95 96)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (127 128)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (150 151)--- numberingORMATION: /note= "discontinuity"(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (188 189)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (193 194)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (208 209)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (243 244)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (247 248)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (259 260)- numbering discontinuity"te= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (262 263)- numbering discontinuity"te= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (275 276)--- numberingORMATION: /note= "discontinuity"(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (298 299)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (308 309)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (326 327)numbering discontinuity"note= "(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 2:SerThrValLysGluGlnLeuIleGluLysLeuIleGluAspAspGlu151015SerGlnCysLysIleThrIleValGlyThrGlyAlaValGlyMetAla202530CysAlaIleSerIleLeuLeuLysAspLeuAlaAspGluLeuAlaLeu354045ValAspValAlaLeuAspLysLeuLysGlyGluMetMetAspLeuGln505560HisGlySerLeuPhePheSerThrSerLysValThrSerGlyLysAsp65707580TyrSerValSerAlaAsnSerArgIleValIleValThrAlaGlyAla859095ArgGlnGlnGluGlyGluThrArgLeuAlaLeuValGlnArgAsnVal100105110AlaIleMetLysIleIleIleProAlaIleValHisTyrSerProAsp115120125CysLysIleLeuValValSerAsnProValAspIleLeuThrTyrIle130135140ValTrpLysIleSerGlyLeuProValThrArgValIleGlySerGly145150155160CysAsnLeuAspSerAlaArgPheArgTyrLeuIleGlyGluLysLeu165170175GlyValHisProThrSerCysHisGlyTrpIleIleGlyGluHisGly180185190AspSerSerValProLeuTrpSerGlyValAsnValAlaGlyValAla195200205LeuLysThrLeuAspProLysLeuGlyThrAspSerAspLysGluHis210215220TrpLysAsnIleHisLysGlnValIleGlnSerAlaTyrGluIleIle225230235240LysLeuLysGlyTyrThrSerTrpAlaIleGlyLeuSerValMetAsp245250255LeuValProLeuLysAsnLeuArgArgValHisProValSerThrMet260265270ValLysGlyLeuTyrGlyIleLysGluGluLeuPheLeuSerIlePro275280285CysValLeuGlyArgAsnGlyValSerAspValValLysIleAspLeu290295300SerGluGluGluAlaLeuLeuLysLysSerAlaGluThrLeuTrpAsn305310315320IleGlnLysAsnLeuIlePhe325(2) INFORMATION FOR SEQ ID NO: 3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 317 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(iii) HYPOTHETICAL: NO(iii) ANTI-SENSE: NO(v) FRAGMENT TYPE: internal(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (15 16)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (28 29)- numbering discontinuity"te= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (29 30)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (30 31)--- numberingORMATION: /note= "discontinuity"(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (40 41)- numbering discontinuity"te= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (69 70)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (73 74)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (83 84)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (115 116)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (138 139)--- numberingORMATION: /note= "discontinuity"(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (176 177)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (181 182)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (196 197)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (211 212)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (230 231)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (234 235)numbering discontinuity"note= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (251 252)- numbering discontinuity"te= "(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (264 265)--- numberingORMATION: /note= "discontinuity"(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: (286 287)numbering discontinuity"note= "(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 3:MetLysAsnAsnGlyGlyAlaArgValValValIleGlyAlaGlyPhe151015ValGlyAlaSerTyrValPheAlaLeuMetAsnGlnGlyIleAlaAsp202530GluIleValLeuIleAspAlaAsnGluSerLysAlaIleGlyAspAla354045MetAspPheAsnHisGlyLysValPheAlaProLysProValAspIle505560TrpHisGlyAspTyrAspAspCysArgAspAlaAspLeuValValIle65707580CysAlaGlyAlaAsnGlnLysProGlyGluThrArgLeuAspLeuVal859095AspLysAsnIleAlaIlePheArgSerIleValGluSerValMetAla100105110SerGlyPheGlnGlyLeuPheLeuValAlaThrAsnProValAspIle115120125LeuThrTyrAlaThrTrpLysPheSerGlyLeuProHisGluArgVal130135140IleGlySerGlyThrIleLeuAspThrAlaArgPheArgPheLeuLeu145150155160GlyGluTyrPheSerValAlaProGlnAsnValHisAlaTyrIleIle165170175GlyGluHisGlyAspThrGluLeuProValTrpSerGlnAlaTyrIle180185190GlyValMetProIleArgLysLeuValGluSerLysGlyGluGluAla195200205GlnLysAspLeuGluArgIlePheValAsnValArgAspAlaAlaTyr210215220GlnIleIleGluLysLysGlyAlaThrTyrTyrGlyIleAlaMetGly225230235240LeuAlaArgValThrArgAlaIleLeuHisAsnGluAsnAlaIleLeu245250255ThrValSerAlaTyrLeuAspGlyLeuTyrGlyGluArgAspValTyr260265270IleGlyValProAlaValIleAsnArgAsnGlyIleArgGluValIle275280285GluIleGluLeuAsnAspAspGluLysAsnArgPheHisHisSerAla290295300AlaThrLeuLysSerValLeuAlaArgAlaPheThrArg305310315(2) INFORMATION FOR SEQ ID NO: 4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 20 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 4:ATTTGTAGCCGCCATCGCGC20(2) INFORMATION FOR SEQ ID NO: 5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 60 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 5:GTCCACAAGGTCTAGACGCGTCTCGCCCGGTTTTTGGTTGGCGCCCGCGGTAATGACAAC60(2) INFORMATION FOR SEQ ID NO: 6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 54 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 6:TTGGTTGCTATTTGCGCCGGCGCCAACCAAAAACCGGGCGAGACGCGGCTTGAT54(2) INFORMATION FOR SEQ ID NO: 7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 54 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: complement (14..19)(D) OTHER INFORMATION: /note= "SacII"(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: complement (50..53)(D) OTHER INFORMATION: /note= "XbaI"(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: complement (44..47)(D) OTHER INFORMATION: /note= "MluI"(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 7:TTGGTTGCTATTACCGCGGGCGCCAACCAAAAACCGGGCGAGACGCGTCTAGAC54(2) INFORMATION FOR SEQ ID NO: 8:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 33 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: 3..7(D) OTHER INFORMATION: /note= "SacII"(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 8:TACCGCGGGCAACATTAAATTGCAACAAGATAA33(2) INFORMATION FOR SEQ ID NO: 9:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 33 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: 3..6(D) OTHER INFORMATION: /note= "XbaI"(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 9:GGTCTAGACGATCGCCCGTCGGGTTATCTTGTT33(2) INFORMATION FOR SEQ ID NO: 10:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 56 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: complement (3..7)(D) OTHER INFORMATION: /note= "SacII"(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: complement (51..54)(D) OTHER INFORMATION: /note= "XbaI"(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 10:TACCGCGGGCAACATTAAATTGCAACAAGATAACCCGACGGGCGATCGTCTAGACC56(2) INFORMATION FOR SEQ ID NO: 11:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 17 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 11:TACCGCGGGCGCCAACT17(2) INFORMATION FOR SEQ ID NO: 12:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 28 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 12:GGTCTAGACGGCCTTTCAAGTTGGCGCC28(2) INFORMATION FOR SEQ ID NO: 13:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 28 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 13:GGTCTAGACGGCCTTTGGAGTTGGCGCC28(2) INFORMATION FOR SEQ ID NO: 14:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 35 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 14:TACCGCGGGCGCCAACTTGAAAGGCCGTCTAGACC35(2) INFORMATION FOR SEQ ID NO: 15:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 35 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: complement (3..7)(D) OTHER INFORMATION: /note= "SacII"(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: complement (30..33)(D) OTHER INFORMATION: /note= "XbaI"(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 15:TACCGCGGGCGCCAACTCCAAAGGCCGTCTAGACC35__________________________________________________________________________
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A method for modifying the specificity or efficiency of an enzyme, while retaining its catalytic activity, is disclosed. The method is characterized by selecting an enzyme, the tertiary structure of which is substantially known or deduced; identifying a single specificity or efficiency-related region of the enzyme; identifying or constructing unique restriction sites bounding the identified region in the DNA coding therefor; generating a DNA sequence which corresponds to at least a portion of the identified region, except that the nucleotides of at least one codon are randomized, using the generated DNA sequence to replace the original such sequence; expressing the DNA including the generated DNA sequence; and selecting for a desired modification so that the DNA coding therefor may be isolated; the randomized DNA being generated by means of a PCR assembly method. Enzyme generated using this method, and having enhanced specificity or efficiency, are also disclosed.
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TECHNICAL FIELD OF THE INVENTION
The present invention relates to an integrated apparatus for generating power and/or oxygen-enriched fluid and a process for the operation thereof.
BACKGROUND OF THE INVENTION
All present oxygen production facilities extract oxygen from air. Air has the advantage of being free and available everywhere. One of the drawbacks is that because air is at atmospheric pressure, it contains a lot of water and CO2 at low partial pressure. And pressure drops in process cycles are energy expensive close to atmospheric pressure. It is the reason why most oil, chemical or petrochemical processes operate in the range of 10-40 bar. The pressure drops are less costly, heat exchange is easier, and the size of plants is reduced, drastically decreasing overall cost.
In the case of oxygen production, as air contains 80% nitrogen, a low pressure waste gas containing the nitrogen is normally produced. In case of cryogenic distillation, the cold heat contained in the waste nitrogen has to be recuperated through heat exchangers which are costly both in investment and related energy needs.
Some oxygen plants operate at higher than normal pressure with some means and additional investment to recover the energy lost in the waste nitrogen.
FIG. 1 shows a basic power gas turbine arrangement in which an air compressor 1 sends air 3 at between 8 and 35 bar to a combustor 5 fed by fuel 6 . The combustion gas 7 mixed with dilution air 4 forms mixture stream 8 which is expanded in gas turbine 9 having an inlet temperature between 900 and 1400° C. and generates power. To achieve good combustion in the bumer, a close to stoichiometric mixing is necessary to use fuel efficiently and produce minimum pollution. But in this case, combustion produces a hot gas at temperatures higher than 2000° C., well above what any kind of hot turbine can accept. For this reason, quench type cooling takes place by mixing this very hot flue gas 7 with compressed dilution air 4 from the compressor at the same pressure as stream 3 but much lower temperature. The dilution air flow 4 is of the same order of magnitude as the combustion air flow 3 .
Because this dilution air 4 does not participate in the combustion, oxygen is not necessary. So it is possible to extract the oxygen contained in the dilution air 4 as shown in FIG. 2 . The air 4 is cooled, purified and distilled in separation unit 12 producing oxygen 10 and nitrogen 11 . The nitrogen 11 is mixed with combustion gas 7 .
Generally the separation unit used is a double column comprising a thermally linked high pressure column and low pressure column. However it is known to use a single column with a top condenser and a bottom reboiler for this purpose.
If the amount of nitrogen 11 is limited, it may alternatively be mixed with air stream 3 and sent to combustor 5 as described in U.S. Pat. No. 4,224,045. Another option is to send the nitrogen to be mixed with the fuel stream 6 .
SUMMARY OF THE INVENTION
According to the present invention, there is provided an integrated apparatus for generating power and/or oxygen enriched fluid comprising a first air separation unit, a gas turbine comprising a combustor and an expander, a first compressor, means for sending air from the first compressor to the combustor and to the air separation unit, means for sending combustion gases from the combustor to the expander, means for sending nitrogen from the air separation unit to a point upstream of the expander and means for either compressing the nitrogen sent to a point upstream of expander, further compressing the air sent to the first air separation unit from the first compressor or expanding the air sent to the combustor from the first compressor
characterized in that the first air separation unit comprises at least a single column fed by air and the apparatus comprises means for sending liquid nitrogen from an external source to the top of the single column, said external source not being a condenser fed by gaseous nitrogen from the top of the single column, and means for removing gaseous nitrogen from the top of the single column and for removing an oxygen-enriched fluid from the bottom of the column.
According to further optional aspects of the invention:
the single column has no bottom reboiler and no top condenser;
the apparatus comprises a second compressor and means for sending air from the further compressor to the single column;
the external source of liquid nitrogen is a second air separation unit comprising at least one distillation column;
the second air separation unit comprises a high pressure column and a low pressure column which are thermally linked;
there are means for withdrawing the liquid nitrogen from the high pressure column or the low pressure column, where necessary pressurizing it and sending it to the top of the single column in liquid form and/or means for sending the oxygen-enriched liquid from the bottom of the single column to the high pressure column and/or the low pressure column;
there are means for sending air to the double column from one of the first, second or a third compressor;
Alternatively there may be means for sending gaseous nitrogen from the single column to the double column and/or means for sending nitrogen from the double column to a point upstream of the expander.
The apparatus may additionally include a gasifier, means for sending oxygen from the air separation unit and a carbon containing substance to the gasifier and means for sending fuel from the gasifier to the combustor.
According to a still further aspect of the invention, there is provided a process for generating power and/or oxygen enriched fluid using an integrated power generation system comprising compressing air in a first compressor, sending air from the first compressor to a combustor and to a first air separation unit, sending nitrogen from the air separation unit to a point upstream of an expander, sending fuel to the combustor, sending combustion gas from the combustor to the expander and either compressing the nitrogen sent to a point upstream of expander, further compressing the air sent to the first air separation unit from the first compressor or expanding the air sent to the combustor from the first compressor
characterized in that the first air separation unit comprises at least one column and the process comprises feeding a column of the first air separation unit column with air, sending liquid nitrogen from an external source to the top of the single column, the external source not being a condenser fed by gaseous nitrogen from the top of the s column and removing gaseous nitrogen from the top of the single column and an oxygen enriched fluid from the bottom of the column.
Further features of the process may include:
said column having no bottom reboiler and no top condenser;
sending air from a second compressor to the single column;
the external source being a second air separation unit comprising at least one column
the external source comprises a high pressure column and a low pressure column which are thermally linked;
withdrawing the liquid nitrogen from the high pressure column, pressurizing and sending it to the top of the column of the first air separation unit;
sending the liquid from the bottom of the single column to the second air separation unit, optionally to the high pressure column or low pressure column of the second air separation unit;
sending air to the second air separation unit from one of the first, second or a third compressor;
sending gaseous nitrogen from the column of the first air separation unit to the second air separation unit;
means for sending nitrogen from the second air separation unit to a point upstream of the expander;
wherein the column of the first air separation unit operates at between 8 and 35 bar;
the highest pressure of the second air separation unit is between 5 and 25 bar;
the amount of air sent from the first compressor to the first air separation unit and the amount of nitrogen sent upstream of the expander differ by no more than 10%, preferably 5%;
all the nitrogen originates from the first air separation unit;
the nitrogen originates from the first air separation unit and the external source;
the external source is the second air separation unit.
In particular the process may be an integrated gasification combined cycle process in which oxygen from the air separation unit is sent to gasify a carbon containing substance thereby producing fuel for the combustor.
BRIEF DESCRIPTION OF THE DRAWING
The invention will now be described in further detail with reference to the FIGS. 3 to 6 which are schematic flow sheets of an integrated air separation unit for use in an integrated power generation system.
DETAILED DESCRIPTION OF THE INVENTION
Cryogenic technology is the basic technology for large air separation plants.
In the process of FIG. 3, air is compressed to between 8 and 35 bar in compressor 1 . Air stream 3 is sent to combustor 5 where it is burnt with fuel 6 . Air stream 4 is cooled in heat exchanger 8 , purified in purifying unit 14 and then cooled in heat exchanger 13 to a temperature suitable for cryogenic distillation. It is then sent to a first air separation unit, in this case a wash column 15 which is a single column fed at the top by a liquid nitrogen wash stream 17 which may be pure or contain up to 5% oxygen. Various sources for the liquid are shown in FIGS. 4 to 6 .
Liquid containing between 27 to 40% oxygen is removed from the bottom of column 15 . Gaseous nitrogen 21 is removed from the column at a pressure between 8 and 25 bar, warmed in exchangers 13 , 8 , reactivates air purification 14 , compressed and mixed either with the combustion gas as shown or with air stream 3 . The mixture thus formed is sent to expander 9 producing external work The nitrogen is compressed in a booster 16 at ambient temperature but may be compressed at sub-ambient or super-ambient temperatures so as to make up for the pressure drop in the exchangers and column. Alternatively air stream 4 may be boosted at any of the temperatures described. A less economical option would be to expand the feed air 3 slightly before sending it to the combustor.
When the air separation from our gas turbine by-pass is done using a liquid nitrogen wash column 15 (FIG. 3 ), we get the following advantages:
all heat exchange (hot and cold) and purification are carried out at elevated pressure thus reducing investment and energy drop cost;
the nitrogen wash column 15 is fed by liquid nitrogen, and very impure oxygen is removed in liquid rich phase. These liquids easily can be pumped and expanded, thus rending this wash totally independent of the rest of the oxygen process;
gaseous nitrogen flow at the outlet of the wash column 15 is almost equal to the air flow at the inlet of this column, thus maintaining the perfect balance of the gas turbine.
In the version of FIG. 4, the liquid nitrogen for the wash column 15 is derived from a second air separation unit comprising a double column with a high pressure column 25 and a low pressure column 27 thermally linked via a reboiler condenser 29 as in standard plants. The system may additionally include an argon separation column fed by the low pressure column. The operating pressures preferably vary between 5 and 25 bar for the high pressure column.
The air for the double column comes from a compressor 30 and is sent to the high pressure column 25 after cooling in exchanger 33 . Oxygen enriched and nitrogen enriched liquids are sent from the high pressure column to the low pressure column as reflux. The system may use a Claude turbine, an turbine feeding air to the low pressure column or a nitrogen turbine to produce refrigeration.
Gaseous oxygen is produced from the low pressure column either directly or by vaporizing liquid oxygen. Waste nitrogen is withdrawn from the low pressure column.
Liquid nitrogen 17 from the top of the high pressure column 25 is sent to the top of wash column 15 following pumping in pump 35 . Liquid 37 from the bottom of column 15 is expanded in a valve 39 and sent to the bottom of the high pressure column or to the low pressure column.
A standard cryogenic oxygen plant has a medium pressure column with liquid nitrogen at the top and oxygen rich liquid at the bottom. If one installs a gas turbine next to an oxygen plant to produce electric power (for the oxygen plant or not) or to produce a combination of power and steam (cogeneration), further arrangement can be made.
With the arrangement of FIG. 4, some liquid nitrogen or poor liquid 17 can be withdrawn from the medium pressure column or any other point of the process such as the low pressure column. It can be pumped to the relevant pressure in order to feed the nitrogen wash column. The corresponding rich liquid 37 will be returned to the low pressure column as the normal rich liquid. Thus some extra oxygen molecules will be fed to the column, allowing increased oxygen production (at the same or reduced purity, depending on the boosting ratio).
Obviously, this interesting process can be used in a grass root plant. In this case, a dedicated cold box will be better suited than a standard plant. Because oxygen is to be replaced by nitrogen or air for the gas turbine, some additional compressed air is needed. It can be injected (FIG. 5) either:
In the cold box 41 via compressor 30 . The necessary pressure will be lower but a second air purification 38 is necessary;
Injected at the inlet of the turbine 9 (before or after the hot exchanger 8 ). No purification is necessary but the corresponding oxygen will be lost (Which is not a problem if the by-pass flow is sufficient for oxygen demand;
Mixed with the by-pass air 4 before nitrogen wash (before or after the hot exchanger 8 ). In that case the existing purification 14 can be used to purify the air.
In certain cases and depending on the final oxygen pressure required, a nitrogen (or air) recycle compressor 43 is necessary to adjust the separation power requirement of the oxygen separation and compression cycle. To maintain the advantages of the global pressurized cycle, this compressor will preferably receive air or nitrogen at medium pressure (above 3 bar).
Refrigeration from oxygen will be recovered in the cold box 41 or within the cold exchanger 13 .
Because the gas at the top of nitrogen wash column is nitrogen, it can be used partly 45 to help the final distillation instead of the recycle compressor. The flow to the turbine can be readjusted as before with air or waste nitrogen recompression 47 . It might have an advantage over a nitrogen recycle compressor as this compressed nitrogen will not need any final cooling (FIG. 6 ).
It will be appreciated that the external source for the liquid nitrogen could be a remote storage tank periodically replenished by tanker trucks or a liquefier in which gaseous nitrogen e.g. from a pipeline is condensed. The oxygen enriched liquid from the first air separation unit may then be sent to another column or another user, or to liquefy after expansion the gaseous nitrogen from the pipe-line.
In the case where the external source is a second air separation unit, this may be a single column air separator generating liquid nitrogen, a standard double column with or without minaret, an external condenser of an air separation column, a double column in which oxygen enriched liquid from the bottom of the low pressure column is fed to a top condenser of the low pressure column, a triple column in which rich liquid from a high pressure column feeds a medium pressure column and liquid from the medium pressure column feeds the low pressure column for example of the type shown in FR1061414 or EP538118.
The second air separation unit serving as an external source may produce other liquids in addition to the nitrogen and other gaseous products. Gases may be produced at high pressure by pumping and vaporizing liquids withdrawn from columns of the second air separation unit.
One advantage of the present system is that the first air separation unit and the second air separation unit can operate independently by providing storage tanks for the liquid nitrogen from the second air separation unit and the oxygen enriched liquid from the first air separation unit.
Thus when the second air separation unit is not operational, the first air separation unit draws liquid nitrogen from the storage. Similarly when the first air separation unit is not operational the oxygen enriched liquid is removed from the storage and sent to the second air separation unit.
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In an integrated power generation system, part of the air from a gas turbine compressor is separated in a single nitrogen wash column to remove oxygen and the gaseous nitrogen produced at the top of the column is sent back to a point upstream of the expander of the gas turbine. The wash column may be fed with liquid nitrogen from an independent air separation unit in which air is separated. Liquid from the bottom of the wash column may be fed back to the air separation unit.
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